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Figure S2C displays probability of progression-free survival over time in subgroups of patients with and without bulky disease

Purpose:In the phase III DUO trial, duvelisib, an oral dual PI3K-δ,γ inhibitor, demonstrated significantly improved efficacy versus ofatumumab [median (m) progression-free survival (PFS), 13.3 vs. 9.9 months (HR, 0.52; P < 0.0001); overall response rate [ORR], 74% vs. 45% (P < 0.0001)], with a manageable safety profile in patients with relapsed/refractory (R/R) chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL). We report results from patients with progressive disease (PD) after ofatumumab who crossed over to duvelisib in the DUO trial.Patients and Methods:Patients with radiographically confirmed PD after ofatumumab received duvelisib 25 mg twice daily in 28-day cycles until PD, intolerance, death, or study withdrawal. The primary endpoint was ORR per investigator. Secondary endpoints included duration of response (DOR), PFS, and safety.Results:As of December 14, 2018, 90 ofatumumab-treated patients in the DUO trial prior to crossover had an ORR of 29%, mDOR of 10.4 months, and mPFS of 9.4 months. After crossover, 77% of patients (69/90) achieved a response, with an mDOR of 14.9 months and mPFS of 15.7 months. Patients with del(17p) and/or TP53 mutations had similar outcomes [ORR, 77% (20/26); mPFS, 14.7 months]. Notably, 73% of patients (47/64) with disease previously refractory to ofatumumab achieved a response. The most frequent any-grade/grade 3/4 treatment-emergent adverse events were diarrhea (47%/23%), neutropenia (26%/23%), pyrexia (24%/4%), cutaneous reactions (23%/4%), and thrombocytopenia (10%/6%).Conclusions:Duvelisib demonstrated high response rates with good durability and a manageable safety profile in patients with R/R CLL/SLL who progressed on ofatumumab, including patients with high-risk disease and disease previously refractory to ofatumumab.

Supplemental Figure Legend

Figure S3 displays probability of overall survival over time in the study population

•Table S1 shows a summary of prior anticancer therapies received by all patients in the study •Table S2 shows best overall response, overall response rate, and duration of response by investigator in the study population of patients while receiving ofatumumab in the parent DUO study before crossover •Table S3 shows rates of all serious TEAEs and individual hematologic and non-hematologic serious TEAEs in {greater than or equal to} 2% of patients in the study population • Table S4 shows rates of all TEAEs leading to death in patients in the study population •Table S5 shows a summary of patient disposition information

Figure S1 displays probability of progression-free survival over time in the study population and in the subgroup of patients with del(17p) and/or TP53 mutations that received ofatumumab while participating in the parent DUO study before crossover

Background: Low-grade serous ovarian cancer (LGSOC) constitutes up to 10% of all ovarian cancer and has clinical and molecular characteristics (resistance to chemotherapy, presence of RAS/RAF mutations, lack of TP53 mutations) distinct from high-grade serous ovarian cancer. Here, we characterized the effects of the dual RAF/MEK inhibitor VS-6766 and the FAK inhibitor defactinib on signal transduction and viability in LGSOC cell lines and patient-derived organoids. To correlate molecular characteristics with clinical response, we characterized genomic alterations in archival tumor samples from patients with LGSOC treated with the combination of VS-6766 and defactinib on a clinical trial (FRAME). Material and Methods: We exposed 5 LGSOC cell lines to clinical Cmax concentrations adjusted for protein binding of VS-6766 and defactinib. We quantified phospho- and total proteins (n=66) with an antibody-bead based assay normalized to GAPDH. We also studied growth inhibitory effects of the combination on KRAS mutant (mt) LGSOC patient-derived organoids. We performed next generation sequencing on archival samples from LGSOC patients treated with VS-6766 in combination with defactinib. Results: Signal transduction changes at 1 hr included reduction of p-FAK in 5/5 cell lines in response to defactinib. Cells exposed to VS-6766 showed a reduction in p-ERK and p-p90-RSK in 4/5 cell lines. Additionally, VS-6766 decreased p-cJUN and increased p-IκB in 4/5 cell lines, changes correlated with apoptosis. At 24 hrs, p-ERK and p-p90-RSK inhibition were maintained in 3/5 cell lines. Both drugs increased cleaved PARP in 4/5 cell lines and VS-6766 increased p-SMAD3 and BIM levels, indicating an increase in cell death/apoptosis. The combination of VS-6766 + defactinib showed synergistic growth inhibition in a KRAS mt LGSOC organoid model (combination index 0.51). The clinical combination of VS-6766 and defactinib (September 2021 cut-off) has shown an objective response rate (ORR) of 11/24 (46%) across all patients with LGSOC, and an ORR of 64% (7/11) for patients with KRAS mt LGSOC (n=11). In addition to mutations in KRAS, emerging data may suggest a correlation of U2AF1 and MED12 mutations with response. Conclusions: VS-6766, the dual RAF/MEK inhibitor, induces significant inhibition of ERK pathway signaling in addition to perturbations in TNF/NFκB signaling. Both defactinib and VS-6766 induce apoptosis in LGSOC models. The results provide mechanistic insights into the encouraging response rates observed in patients with LGSOC treated with VS-6766 and defactinib (NCT03875820). These data support the ongoing randomized phase II ENGOTov60/GOG3052/RAMP201 study (NCT04625270). Citation Format: Adam R. Stewart, Lisa Pickard, Ekta Paranjape, Victoria Sanchez Perez, Sanjib Chowdhury, Stephanie Lustgarten, Silvia Coma, Jonathan A. Pachter, Mark S. Carey, Gabriel DiMattia, Hannah C. Badham, Toby Prout, Mona Parmar, Muneeb Mahmud, Christina Yap, Matthew G. Krebs, Susana Banerjee, Udai Banerji. Mechanistic evaluation of VS-6766 (dual RAF/MEK inhibitor) and defactinib (FAK inhibitor) in low-grade serous ovarian cancer models with correlations to clinical response [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3476.

Purpose: In the phase III DUO trial, duvelisib, an oral dual PI3K-δ,γ inhibitor, demonstrated significantly improved efficacy versus ofatumumab [median (m) progression-free survival (PFS), 13.3 vs. 9.9 months (HR, 0.52; P < 0.0001); overall response rate [ORR], 74% vs. 45% (P < 0.0001)], with a manageable safety profile in patients with relapsed/refractory (R/R) chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL). We report results from patients with progressive disease (PD) after ofatumumab who crossed over to duvelisib in the DUO trial. Patients and Methods: Patients with radiographically confirmed PD after ofatumumab received duvelisib 25 mg twice daily in 28-day cycles until PD, intolerance, death, or study withdrawal. The primary endpoint was ORR per investigator. Secondary endpoints included duration of response (DOR), PFS, and safety. Results: As of December 14, 2018, 90 ofatumumab-treated patients in the DUO trial prior to crossover had an ORR of 29%, mDOR of 10.4 months, and mPFS of 9.4 months. After crossover, 77% of patients (69/90) achieved a response, with an mDOR of 14.9 months and mPFS of 15.7 months. Patients with del(17p) and/or TP53 mutations had similar outcomes [ORR, 77% (20/26); mPFS, 14.7 months]. Notably, 73% of patients (47/64) with disease previously refractory to ofatumumab achieved a response. The most frequent any-grade/grade 3/4 treatment-emergent adverse events were diarrhea (47%/23%), neutropenia (26%/23%), pyrexia (24%/4%), cutaneous reactions (23%/4%), and thrombocytopenia (10%/6%). Conclusions: Duvelisib demonstrated high response rates with good durability and a manageable safety profile in patients with R/R CLL/SLL who progressed on ofatumumab, including patients with high-risk disease and disease previously refractory to ofatumumab.

Relapsed or refractory (R/R) peripheral T-cell lymphoma (PTCL) is an aggressive lymphoma with a median overall survival (OS) of 6 months. Most approved therapies have overall response rates (ORR) of < 30%, low complete response (CR) rates, and short progression free survival (PFS). Duvelisib (DUV), a dual PI3K-δ,γ inhibitor, is FDA approved at 25 mg twice daily (BID) for the treatment of R/R chronic lymphocytic leukemia or small lymphocytic lymphoma after ≥ 2 lines of prior therapy and R/R follicular lymphoma after ≥ 2 prior systemic therapies, the latter based on accelerated approval. DUV monotherapy demonstrated an ORR of 50% in patients (pts) with R/R PTCL in a Phase 1 study across multiple subtypes (Horwitz, Blood 2018). In the Phase 2, open-label, multi-center, PRIMO trial of DUV in R/R PTCL, the initial results of the dose-optimization phase (N=33) showed a 54% ORR in the 75 mg BID (N=13) and 35% in the 25 mg BID (N=20) cohorts by investigator assessment (INV) , the primary endpoint (Horwitz, ASH 2019). We report mature dose-optimization results and the initial results of a planned preliminary assessment (N=20) of the dose-expansion (NCT03372057; supported by Verastem Oncology). In the dose-optimization phase, pts received DUV at 25 mg (Cohort 1) or 75 mg BID (Cohort 2). Pts were evaluable if they completed 1 cycle (28 days) of DUV and had ≥ 1 efficacy assessment. The dose-expansion phase is ongoing with a targeted enrollment of 100 pts; pts were eligible if they had histologically confirmed R/R PTCL after ≥2 cycles of a prior standard regimen and a CD4 lymphocyte count of ≥ 50/mm3 (0.05 x 109/L). Based on the initial dose-optimization results, it was determined pts will receive DUV starting at 75 mg BID for 2 cycles to achieve more rapid tumor control, followed by 25 mg to try to maintain long-term disease control and mitigate the potential for later onset toxicities. Pts were to be maintained on therapy continuously until progressive disease (PD) or unacceptable toxicity. For those at 25mg BID, it was permitted for the dose to be re-escalated to 75 mg BID if an assessment shows PD and the pt had not required a dose modification due to toxicity. The primary endpoint is ORR by an Independent Review Committee (IRC), and secondary endpoints include duration of response (DOR), PFS, OS, disease control rate, and safety; all analyses consisted of pts that received at least 1 dose of DUV. The statistical analysis plan was amended to take a preliminary assessment of ORR after approximately 20 pts were evaluated for response in the dose-expansion phase, consistent with the number of pts that were evaluated in the dose-optimization phase (Cohort 2). Dose-Optimization Phase Efficacy Update: As of the data cutoff, 2 pts (1 each cohort) remain on treatment. Efficacy data are summarized in Table 1. Of those pts that achieved a CR, 1 in each cohort proceeded to undergo stem cell transplant or consolidated radiation therapy with curative intent, and are censored in the DOR assessment . Dose-Expansion Phase Initial Summary: As of the data cutoff of 23 March 2020, a total of 25 pts have been dosed, 20 of whom underwent at least 1 disease response assessment (Table 1). Pts had a median age of 61 years (range, 21-86 years) and a median of 2 prior therapies (range, 1-6). Forty-five percent (9/20) of pts remain on treatment (5 responders, 3 with assessments not yet performed, 1 on treatment with stable disease);11 pts discontinued due to PD (n=7), adverse events (n=2) , or to under go transplant (n=2). Responses occurred in 8/20 pts: PTCL-NOS (4 CR, 1 partial response [PR]), ALCL (1 PR), AITL (1 CR) and SPTCL (1 CR). The most frequent adverse events seen were neutrophil count decreased (25%), ALT increased (21%), WBC decreased (21%) and lymphocyte count decreased (21%). In summary, the DUV data observed to date show consistent response rates in a R/R PTCL pt population. The safety profile observed in PRIMO to date is consistent with the current safety profile of DUV. The mature dose-optimization phase results demonstrated a median DOR of 12.2 months for the 75 mg BID cohort. The preliminary results from the PRIMO dose-expansion cohort (75 mg BID followed by 25 mg BID dosing) show an ORR of 40 % and CR rate of 30% (6/20) by INV assessment. These data support continued evaluation of DUV as a treatment option for R/R PTCL. Updated data from the planned interim analysis after 40 pts enroll (occurred June 2020) will be presented. Disclosures Pro: Verastem Oncology: Research Funding. Brammer:Bristol-Myers Squibb: Research Funding; Celgene: Research Funding; Seattle Genetics: Honoraria, Speakers Bureau; Kymera: Honoraria; Verastem Oncology: Other: Travel. Jacobsen:Takeda: Honoraria; Merck, Pharmacyclics, F. Hoffmann-LaRoche, Novartis: Research Funding; Acerta, AstraZeneca, Merck: Consultancy. Mehta-Shah:Corvus: Research Funding; Verastem: Research Funding; Celgene: Research Funding; Bristol Myers-Squibb: Research Funding; Genetech/Roche: Research Funding; C4 Therapeutics: Consultancy; Karyopharm Therapeutics: Consultancy; Innate Pharmaceuticals: Research Funding; Kyowa Hakko Kirin: Consultancy. Zain:Seattle Genetics: Research Funding; Kyowa Kirlin: Research Funding; Mundai Pharma: Research Funding. Zinzani:Immune Design: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Merck: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; MSD: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sandoz: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen-Cilag: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celltrion: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Verastem: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees; ADC Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kirin Kyowa: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; EUSA Pharma: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Servier: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; TG Therapeutics, Inc.: Honoraria, Speakers Bureau; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Portola: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Eusapharma: Consultancy, Speakers Bureau; Kyowa Kirin: Consultancy, Speakers Bureau; Immune Design: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Lustgarten:Verastem Oncology: Current Employment, Current equity holder in publicly-traded company. Youssoufian:Verastem Oncology: Current Employment, Current equity holder in publicly-traded company. Horwitz:Janssen: Consultancy; GlaxoSmithKline: Consultancy; Daiichi Sankyo: Research Funding; C4 Therapeutics: Consultancy; Beigene: Consultancy; Portola: Consultancy, Research Funding; Mundipharma: Consultancy; Innate Pharma: Consultancy; Corvus: Consultancy; Trillium: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Millenium/Takeda: Consultancy, Research Funding; Kyowa Hakka Kirin: Consultancy, Research Funding; Infinity/Verastem: Research Funding; Forty Seven: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Aileron: Consultancy, Research Funding; ADCT Therapeutics: Consultancy, Research Funding; Vividion Therapeutics: Consultancy; Verastem: Consultancy, Research Funding; Myeloid Therapeutics: Consultancy; Miragen: Consultancy; Kura Oncology: Consultancy; ASTEX: Consultancy; Affirmed: Consultancy. OffLabel Disclosure: Duvelisib (DUV), a dual PI3K-δ,γ inhibitor, is FDA approved at 25 mg twice daily (BID) for the treatment of R/R chronic lymphocytic leukemia or small lymphocytic lymphoma after at least 2 lines of prior therapy and R/R follicular lymphoma after at least 2 prior systemic therapies, the latter based on accelerated approval. This indication is approved under accelerated approval based on overall response rate. Continued approval for this indication may be contingent upon verification and description of clinical benefit in confirmatory trials. Duvelisib is not approved for Peripheral T-Cell Lymphoma. This study is investigating treatment or outcomes that have not received approval from a Health Authority. The information presented is not intended to convey conclusions of safety or efficacy. There is no guarantee that the outcome of these studies will result in approval by a Health Authority.

PURPOSE Indolent non-Hodgkin lymphoma (iNHL) remains largely incurable and often requires multiple lines of treatment after becoming refractory to standard therapies. Duvelisib was approved by the Food and Drug Administration for relapsed or refractory (RR) chronic lymphocytic leukemia or small lymphocytic lymphoma (SLL) and RR follicular lymphoma (FL) after two or more prior systemic therapies. On the basis of the activity of duvelisib, a first-in-class oral dual inhibitor of phosphoinositide 3-kinase-δ,-γ, in RR iNHL in a phase I study, the safety and efficacy of duvelisib monotherapy was evaluated in iNHL refractory to rituximab and either chemotherapy or radioimmunotherapy. PATIENTS AND METHODS Eligible patients had measurable iNHL (FL, SLL, or marginal zone B-cell lymphoma) double refractory to rituximab (monotherapy or in combination) and to either chemotherapy or radioimmunotherapy. All were treated with duvelisib 25 mg orally twice daily in 28-day cycles until progression, unacceptable toxicity, or death. The primary end point was overall response rate (ORR) using the revised International Working Group criteria for malignant lymphoma. RESULTS This open-label, global phase II trial enrolled 129 patients (median age, 65 years; median of three prior lines of therapy) with an ORR of 47.3% (SLL, 67.9%; FL, 42.2%; MZL, 38.9%). The estimated median duration of response was 10 months, and the estimated median progression-free survival was 9.5 months. The most frequent any-grade treatment-emergent adverse events (TEAEs) were diarrhea (48.8%), nausea (29.5%), neutropenia (28.7%), fatigue (27.9%), and cough (27.1%). Among the 88.4% of patients with at least one grade 3 or greater TEAE, the most common TEAEs were neutropenia (24.8%), diarrhea (14.7%), anemia (14.7%), and thrombocytopenia (11.6%). CONCLUSION In the DYNAMO study, oral duvelisib monotherapy demonstrated clinically meaningful activity and a manageable safety profile in heavily pretreated, double-refractory iNHL, consistent with previous observations. Duvelisib may provide a new oral treatment option for this patient population of which many are elderly and in need of additional therapies.

The third-generation tyrosine kinase inhibitor (TKI) ponatinib shows activity against all common BCR-ABL1 single mutants, including the highly resistant BCR-ABL1-T315I mutant, improving outcome for patients with refractory chronic myeloid leukemia (CML). However, responses are variable, and causal baseline factors have not been well-studied. The type and number of low-level BCR-ABL1 mutations present after imatinib resistance has prognostic significance for subsequent treatment with nilotinib or dasatinib as second-line therapy. We therefore investigated the impact of low-level mutations detected by sensitive mass-spectrometry before ponatinib initiation (baseline) on treatment response in 363 TKI-resistant patients enrolled in the PONATINIB for Chronic Myeloid Leukemia Evaluation and Ph+ Acute Lymphoblastic Leukemia trial, including 231 patients in chronic phase (CP-CML). Low-level mutations were detected in 53 patients (15%, including low-level T315I in 14 patients); most, however, did not undergo clonal expansion during ponatinib treatment and, moreover, no specific individual mutations were associated with inferior outcome. We demonstrate however, that the number of mutations detectable by mass spectrometry after TKI resistance is associated with response to ponatinib treatment and could be used to refine the therapeutic approach. Although CP-CML patients with T315I (63/231, 27%) had superior responses overall, those with multiple mutations detectable by mass spectrometry (20, 32%) had substantially inferior responses compared with those with T315I as the sole mutation detected (43, 68%). In contrast, for CP-CML patients without T315I, the inferior responses previously observed with nilotinib/dasatinib therapy for imatinib-resistant patients with multiple mutations were not seen with ponatinib treatment, suggesting that ponatinib may prove to be particularly advantageous for patients with multiple mutations detectable by mass spectrometry after TKI resistance. Refereed/Peer-reviewed

Background Duvelisib, an oral dual PI3K-δ and PI3K-γ inhibitor, is approved by the US Food and Drug Administration for the treatment of adult patients with relapsed or refractory (R/R) follicular lymphoma (FL) after ≥ 2 prior systemic therapies. In multiple phase 1-3 studies that included patients with iNHL, duvelisib was shown to be efficacious, with a favorable risk-benefit profile. This study will evaluate whether duvelisib efficacy at the approved 25 mg twice daily (BID) dose can be achieved and maintained with an acceptable or improved safety profile by the inclusion of prespecified 2-week drug holidays in patients with R/R iNHL. Study Design and Methods TEMPO is a randomized, open-label, multicenter, international, phase 2 study of duvelisib in adult patients with R/R iNHL in whom ≥ 1 line of prior therapy has failed. The primary objective is to evaluate the efficacy of duvelisib administered with prescribed drug holidays, with the primary endpoint of overall response rate (ORR) by the 2007 revised International Working Group criteria. Key secondary endpoints include ORR by the 2014 Lugano criteria, progression-free survival, overall survival, time to treatment failure, duration of response, lymph node response rate, time to the first response, adverse event profile, and determination of pharmacokinetics parameters. Exploratory objectives include assessment of quality of life and biomarkers of treatment response and toxicity. Key inclusion criteria include histologically confirmed FL grades 1 to 3a, marginal zone lymphoma (splenic, nodal, or extranodal) or small lymphocytic lymphoma, radiological evidence of disease progression and ≥ 1 bidimensionally measurable lesion ≥ 1.5 cm, adequate organ function, and Eastern Cooperative Oncology Group performance status ≤ 2. Key exclusion criteria include prior allogeneic hematopoietic stem cell transplant; previous treatment with a PI3K inhibitor; history of drug-induced colitis or drug-induced pneumonitis; ongoing treatment for systemic infection; central nervous system NHL; prolonged QT interval; history of tuberculosis treatment within the 2 past years; history of stroke, unstable angina, myocardial infarction, or ventricular arrhythmia requiring medication or mechanical control within the past 6 months; history of or concurrent interstitial lung disease of any severity and/or severely impaired lung function; ongoing treatment with chronic immunosuppressants; and any unstable or severe uncontrolled medical condition. A total of 102 patients are planned to be enrolled. Patients will be randomized 1:1 to 2 arms and stratified by number of prior therapies (1 or > 1), bulky disease status (longest diameter of baseline lesion < 5 cm or ≥ 5 cm), and time since last recurrence (≥ 24 months or < 24 months). In arm 1, patients will receive duvelisib 25 mg BID for one 10-week (W) cycle followed by 25 mg BID on W3 and W4 of each subsequent 4-week cycle. In arm 2, patients will receive duvelisib 25 mg BID on W1, W2, W5, W6, W9, and W10 of one 10-week cycle and then on W3 and W4 of each subsequent 4-week cycle. Patients will be treated until disease progression, unacceptable toxicity, or withdrawal. This study will test the null hypothesis that the ORR in each arm is ≤ 30% against the alternative that the ORR is ≥ 55%. The study has a 2-stage design. In stage 1, 15 patients will be enrolled in each arm, with response assessment after ≥ 3 cycles. If there are fewer than 6 partial or complete responses, consideration may be given to terminating the arm. Otherwise, in stage 2, 36 additional patients will be enrolled, for a total of 51 per arm. Enrollment is planned to be initiated in August 2019. Approximately 50 sites will be open for enrollment across the United States, Europe, and Asia. Disclosures Karmali: Takeda, BMS: Other: Research Funding to Institution; Gilead/Kite; Juno/Celgene: Consultancy, Speakers Bureau; Astrazeneca: Speakers Bureau. Youssoufian:Verastem Oncology: Consultancy, Equity Ownership. Sprott:SMOC Therapeutics: Employment, Equity Ownership; Verastem Oncology: Employment, Equity Ownership. Weaver:FemtoDx: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties: Inventor; Verastem Oncology: Employment, Equity Ownership, Patents & Royalties: Inventor; Hillstream Biopharma: Consultancy, Equity Ownership. Narasimhan:Verastem: Employment, Equity Ownership. Lustgarten:Verastem: Employment. Patrick:Verastem Oncology: Employment. Zalutskaya:Verastem Inc: Employment, Equity Ownership. Gordon:Gilead: Other: Advisory Board; Juno/Celgene: Other: Advisory Board, Research Funding; Zylem LLC: Other: co-founder; research in nanoparticles in cancer; Bayer: Other: Advisory Board. OffLabel Disclosure: Duvelisib (DUV), a dual PI3K-delta,gamma inhibitor, is US FDA approved at 25 mg twice daily (BID) for the treatment of R/R chronic lymphocytic leukemia or small lymphocytic lymphoma after at least 2 lines of prior therapy and R/R follicular lymphoma after at least two prior systemic therapies.

Ponatinib has potent activity against native and mutant BCR-ABL1, including BCR-ABL1T315I. The pivotal phase 2 Ponatinib Ph+ ALL and CML Evaluation (PACE) trial evaluated efficacy and safety of ponatinib at a starting dose of 45 mg once daily in 449 patients with chronic myeloid leukemia (CML) or Philadelphia chromosome–positive acute lymphoblastic leukemia (ALL) resistant/intolerant to dasatinib or nilotinib, or with BCR-ABL1T315I. This analysis focuses on chronic-phase CML (CP-CML) patients (n = 270) with 56.8-month median follow-up. Among 267 evaluable patients, 60%, 40%, and 24% achieved major cytogenetic response (MCyR), major molecular response (MMR), and 4.5-log molecular response, respectively. The probability of maintaining MCyR for 5 years was 82% among responders. Dose reductions were implemented in October 2013 to decrease the risk of arterial occlusive events (AOEs); ≥90% of CP-CML patients who had achieved MCyR or MMR maintained response 40 months after elective dose reductions. Estimated 5-year overall survival was 73%. In CP-CML patients, the most common treatment-emergent adverse events were rash (47%), abdominal pain (46%), thrombocytopenia (46%), headache (43%), dry skin (42%), and constipation (41%). The cumulative incidence of AOEs in CP-CML patients increased over time to 31%, while the exposure-adjusted incidence of new AOEs (15.8 and 4.9 per 100 patient-years in years 1 and 5, respectively) did not increase over time. These final PACE results demonstrate ponatinib provides durable and clinically meaningful responses, irrespective of dose reductions, in this population of heavily pretreated CP-CML patients. This trial was registered at www.clinicaltrials.gov as #NCT01207440.

We compared the efficacy of ponatinib and second-generation tyrosine kinase inhibitors (2G-TKIs: bosutinib, dasatinib, and nilotinib) in chronic phase CML resistant/intolerant to ≥1 prior 2G-TKI. Estimated probabilities of CCyR with 2G-TKI ranged from 22% to 26%, compared with 60% (95% CrI 52-68%) with ponatinib. The estimated probability of ponatinib providing higher response rate than all other included treatments was 99% (CCyR) and 97% (MCyR). Use of further 2G-TKI may provide limited benefit in CP-CML patients resistant/intolerant to prior 2G-TKI treatment. Compared with 2G-TKIs, ponatinib is estimated to provide substantially higher probability of achieving CCyR and MCyR; safety was not compared.

In this ongoing Phase 1/2 study (NCT01667133), we evaluated ponatinib and assessed its recommended dose in Japanese patients with chronic myeloid leukemia (CML) resistant/intolerant to dasatinib or nilotinib, or with Philadelphia chromosome–positive acute lymphoblastic leukemia (Ph+ALL) resistant/intolerant to ≥1 tyrosine kinase inhibitor (TKI). The primary endpoints were safety of the recommended dose (Phase 1) and major cytogenetic response (MCyR) by 12 months in chronic-phase CML (CP-CML) patients or major hematologic response (MaHR) by 6 months in patients with advanced phase disease (Phase 2). MCyR was achieved/maintained by 12 months in 65% of CP-CML patients; MaHR was achieved by 6 months in 61% of patients with advanced phase disease. The most common nonhematologic grade 3/4 treatment-emergent adverse event (AE) was hypertension (37%); common hematologic grade 3/4 AEs were thrombocytopenia (57%), neutropenia (34%), and leukopenia (26%). Overall, five (14%) patients experienced arterial occlusive events (AOEs); no grade 5 AOEs were reported. The steady-state accumulation ratio of ponatinib (based on area under the curve) ranged from 2.6 (15 mg/day) to 1.3 (45 mg/day). In summary, ponatinib demonstrated efficacy in Japanese patients with CML and Ph+ALL resistant/intolerant to prior TKI treatment; safety data support a recommended starting dose of 45 mg/day in these patients.

7523 Background: Duvelisib (DUV), a first-in-class oral dual PI3K-δ,γ inhibitor, is approved for treatment (tx) of R/R CLL/SLL after ≥ 2 prior therapies. In the phase 3 DUO trial, DUV 25 mg BID significantly improved efficacy vs ofatumumab (OFA; mPFS, 13.3 vs 9.9 mo; HR, 0.52 [ P < .0001]; ORR, 74% vs 45% [ P < .0001]) in pts with R/R CLL/SLL. Tx-emergent AEs (TEAEs) of special interest (AESIs) such as infections, diarrhea, colitis, neutropenia, rash, ALT/AST elevation, and pneumonitis, were moderate and manageable with early intervention and dose modification. We examined dose-modification patterns and their impact on response to DUV in the DUO trial. Methods: Dose interruptions (DI) or reductions (DR) to 15, 10, or 5 mg BID were permitted per study protocol to manage TEAEs. Responses were assessed by IRC. Results: Among 158 DUV-treated pts, median duration of DUV exposure was 11.6 mo (vs 5.3 mo, OFA). DI and DR occurred in 80% (126/158) and 27% (43/158) of pts, respectively. The most common cause of DI was diarrhea (23%), followed by neutropenia (12%) and pneumonia or colitis (11% each). Among responders (n = 118), median time to first response on DUV was 1.9 mo and estimated median duration of response was 11.1 mo. Median time to first DI was 3.9 mo and median duration of DI was 15 d (range, 1-133 d). Response to DUV was improved or maintained in most pts evaluated for response who had ≥ 1 DI for > 1 wk (84% [42/50]) or > 2 wk (82% [31/38]) followed by ≥ 3 wk on DUV. In a landmark analysis, median PFS was similar in pts with DI and those without DI for > 1 wk (17.8 vs 16.3 mo) or > 2 wk (17.8 vs 16.3 mo) within the first 3 mo. The median time to DR after CR/PR was 5.6 mo (n = 25) and median duration was 3.4 mo. Median time to onset across AESIs after starting DUV ranged from 2.2 to 4.3 mo; median time to resolution was within 4 wk across AESIs. Proportions of pts experiencing AESIs were stable or decreased over time after 3-6 mo: 0-3 mo, 64% (101/158); > 3-6 mo, 63% (86/137); > 6-9 mo, 47% (54/114); > 9-12 mo, 52% (52/100), and seldom led to discontinuation of DUV (≤ 10%). Conclusions: DI/DR can contribute to the effective management of TEAEs with DUV. These findings suggest that DI of > 1-2 weeks or more do not appear to significantly impact response to DUV or PFS. Clinical trial information: NCT02004522.

Introduction: Indolent NHL (iNHL) remains largely incurable, with the majority of patients (pts) eventually becoming refractory to standard therapies, necessitating new effective and tolerable treatments. Duvelisib is an oral dual PI3K-δ,γ inhibitor being developed for the treatment of hematologic malignancies, including CLL/SLL and follicular lymphoma (FL). In the Phase 2 DYNAMO trial of duvelisib monotherapy for relapsed/refractory iNHL(NCT01882803), the FL subgroup (n=83) had a median progression-free survival (mPFS) of 8.3 months (mo) and an overall response rate (ORR) of 43%. Although adverse events (AEs) observed with other PI3K-inhibitors also occurred with duvelisib, they infrequently led to discontinuation of treatment. An understanding of prognostic factors that can inform duvelisib responsiveness would be valuable for guiding patient selection treatment options. This study presents updated data on prognostic factors potentially associated with duvelisib efficacy and safety. Methods: To identify FL risk subgroups, clinical parameters were assessed according to the FL Prognostic Index (FLIPI). Incidences of AEs (per combined preferred term: neutropenia, diarrhea, colitis, pneumonia, pneumonitis, transaminase elevation, rash, and infections) were also evaluated for associations with clinical responses. Blood collected at baseline (Cycle1 Day1) was analyzed by a central laboratory for a 7 gene expression signature to generate the combined M7-FLIPI, and biopsies were evaluated at screening for del(6q) cytogenetics. In addition, baseline immune cell counts (subgrouped low [L] or high [H] by flow cytometry), and levels of key chemokines, cytokines, and serum factors were centrally assessed. Multivariate regression models were developed via a stepwise procedure from a selection of these parameters identified by individual univariate analysis for the efficacy endpoints of mPFS and ORR. Results: In the DYNAMO study, there were no significant differences in mPFS, ORR, or lymph node response rate (LNRR) identified for FL pts between high and low risk subgroups stratified by prognostic indexes. Efficacy responses were similar using the FLIPI (FLIPI Prognostic factors selected via univariate analyses for mPFS or ORR were advanced into multivariate models. None of these factors reached significance in a multivariate mPFS model, and only CD3H was significant in a stepwise ORR model (odds ratio H/L=2.69, 95% CI [1.20,6.06]). The FL pt subgroups having AEs were evaluated for mPFS (mo [95% CI] as follows: neutropenia, 8.3 mo [3.5,11.8], n=25; diarrhea 11.0 mo [8.3,16.4], n=40; colitis 10.0 mo [8.3,24.0], n=5; rash 8.3 mo [1.9,28.0], n=26; transaminase elevation, 11.8 mo [1.4,24.0], n=12; pneumonitis 13.0 mo [9.5,16.4], n=4; pneumonia 12.0 [4.2,28.0], n=8; and infection 9.0 [3.7,12.0], n=38. Conclusion In the Phase 2 DYNAMO study, mPFS and ORR were similar for duvelisib-treated FL pts regardless of poor prognostic indicators, including FLIPI, M7-FLIPI, and chromosome 6q deletions. Elevated levels of CXCL11 and IL2RA correlated with shorter mPFS. This analysis also shows that AEs, when managed, allow continued treatment with duvelisib and increased benefit as demonstrated by mPFS. Overall, these data suggest that duvelisib as a single-agent is effective in FL patients, including pts with poor prognostic factors. Disclosures Zinzani: SERVIER: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Merck: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celltrion: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; Merck: Honoraria, Membership on an entity's Board of Directors or advisory committees; TG Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bayer: Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Speakers Bureau; Takeda: Membership on an entity's Board of Directors or advisory committees; Bayer: Membership on an entity's Board of Directors or advisory committees; MSD: Honoraria, Speakers Bureau; PFIZER: Honoraria, Membership on an entity's Board of Directors or advisory committees; PFIZER: Honoraria, Membership on an entity's Board of Directors or advisory committees; TG Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; Verastem: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Astra Zeneca: Speakers Bureau; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Flinn:Novartis: Research Funding; Infinity: Research Funding; Takeda: Research Funding; Gilead: Research Funding; Trillium: Research Funding; Constellation: Research Funding; Curis: Research Funding; Verastem: Research Funding; TG Therapeutics: Research Funding; Verastem: Consultancy, Research Funding; BeiGene: Research Funding; Calithera: Research Funding; Constellation: Research Funding; Celgene: Research Funding; Seattle Genetics: Research Funding; Forty Seven: Research Funding; Merck: Research Funding; Gilead: Research Funding; Takeda: Research Funding; Pharmacyclics: Research Funding; Verastem: Research Funding; Trillium: Research Funding; Portola: Research Funding; TG Therapeutics: Research Funding; Forma: Research Funding; Forma: Research Funding; Genentech: Research Funding; ArQule: Research Funding; Genentech: Research Funding; Incyte: Research Funding; Agios: Research Funding; ArQule: Research Funding; Pfizer: Research Funding; Portola: Research Funding; Novartis: Research Funding; BeiGene: Research Funding; Celgene: Research Funding; Kite: Research Funding; Kite: Research Funding; Merck: Research Funding; Forty Seven: Research Funding; Pfizer: Research Funding; Agios: Research Funding; Seattle Genetics: Research Funding; Verastem: Consultancy, Research Funding; Calithera: Research Funding; Infinity: Research Funding; Janssen: Research Funding; Curis: Research Funding; Incyte: Research Funding; Janssen: Research Funding; Pharmacyclics: Research Funding. Miller:CTI: Research Funding; Gilead: Honoraria, Research Funding; Incyte: Consultancy, Honoraria, Research Funding, Speakers Bureau; Novartis: Honoraria, Speakers Bureau. Ardeshna:Celgene: Membership on an entity's Board of Directors or advisory committees; ADC Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees, Other: Conference expenses, Research Funding. Le:Verastem Oncology: Employment. Pachter:Verastem Inc: Employment, Other: Stockholder. Sprott:Verastem Oncology: Employment. Lustgarten:Verastem Oncology: Employment. Weaver:Verastem Oncology: Employment, Other: Stockholder; Agios Pharmaceuticals: Employment; Femto Dx: Equity Ownership. Wagner-Johnston:Novartis: Research Funding; ASTEX: Research Funding; Celgene: Research Funding; JUNO: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Merck: Research Funding; ADC Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees.

Background: Duvelisib (DUV) is a first-in class, oral dual inhibitor of PI3K-δ,-γ being developed for the treatment of advanced B- and T-cell malignancies. To date 304 patients (pts) with relapsed/refractory (RR) CLL/SLL have been treated with DUV monotherapy 25 mg BID in 4 studies: Study IPI-145-02 [NCT01476657], a Phase 1 study in advanced hematologic malignancies; DYNAMOTM [NCT01882803], a Phase 2 study in iNHL; DUOTM [NCT02004522], a Phase 3 study in CLL/SLL; and Study IPI-145-12 [NCT02049515], a Phase 3 crossover study from DUO. Here we present pooled efficacy and safety analyses from these 4 studies in RR CLL/SLL, examining the baseline characteristics, incidence and timing of AEs, and response in the subset of pts who received DUV monotherapy for >2 years in order to characterize the factors that contribute to long-term treatment with DUV. Methods: In this analysis we examined pts treated with DUV for >2 years (n=45) referred to as long-term (LT) pts. Efficacy and safety data from 4 studies of DUV monotherapy in pts with RR CLL/SLL treated at 25 mg BID were pooled. Response was based on investigator assessment per IWCLL/IWG criteria. Treatment-emergence (TE) was defined as those adverse events (AEs) that occurred from first dose to 30 days post last dose of DUV. All AEs were coded using MedDRA version 16.1; severity was assessed by investigators according to the National Cancer Institute-Common Terminology Criteria for Adverse Events version 4.03. Results: Baseline characteristics of LT pts were similar to pts who discontinued The median exposure for LT pts was 31 months, with 20 pts on DUV >3 years and 3 pts on DUV >4 years. The majority of LT pts (60%) remain on treatment as of June 2018. The median PFS in LT pts was 37 months, with an investigator-assessed ORR of 89%; best responses included 16% CR/CRi, 73% PR, and 11% SD. Among LT pts, 98% had an AE, 80% had a ≥ Gr 3 AE, 46% an SAE, and 9% an AE leading to discontinuation (after 2 years on DUV); 69% of pts had at least 1 dose modification due to an AE (69% hold, 40% reduction). Table 1 shows the incidence of AEs in LT pts by 6-month treatment intervals. Overall, ≥ Gr 3 AEs occurred less frequently over time but still occurred in 27% pts after 2 years. The rate of colitis was consistent over the 2 years of treatment (≤ 2.2% per 6-month interval). No ≥ Gr 3 AEs of diarrhea were observed within the first 6 months of treatment, while the overall rate of all grade diarrhea was consistent over time (16-27% per 6-month interval); dose modification for the management of diarrhea increased over time allowing pts to remain on therapy. Neutropenia, ALT increase, and lipase increase were more common in the first 6 months; most ≥ Gr 3 AEs of neutropenia did not require any dose modification. Compared to all pts with RR CLL/SLL treated with DUV (n=442), the incidences and types of AEs in LT pts were generally similar. Four (9%) LT pts discontinued DUV due to an AE, and included: colitis (n=2), diarrhea (n=1), Clostridium difficile colitis (n=1), and rectal adenocarcinoma (n=1). Pneumocystis jirovecii pneumonia occurred in 1 LT pt (not on prophylaxis at the time) and was the only opportunistic infection reported for this population. There have been no fatal events in the LT pts. Conclusions: 45 pts with RR CLL/SLL have been on DUV 25 mg BID for >2 years, with a median of 31 months on treatment. The investigator-assessed ORR for these long-term pts was 89% (16% CR/CRi, 78% PR) and the median PFS was 37 months. A majority (60%) of the long-term pts remain on treatment. Baseline characteristics were similar in these long-term pts compared to pts who discontinued < 2 years. Most of the commonly occurring ≥ Gr 3 AEs decreased over time, with the exception of diarrhea. The majority of ≥ Gr 3 AEs were managed through dose modification (dose interruption and or reduction). These data support DUV monotherapy as a long-term treatment option for pts with RR CLL/SLL with the potential for durable response and good tolerability over time. Disclosures Flinn: ArQule: Research Funding; Infinity: Research Funding; Verastem: Research Funding; BeiGene: Research Funding; Curis: Research Funding; Merck: Research Funding; Seattle Genetics: Research Funding; Agios: Research Funding; Forma: Research Funding; Portola: Research Funding; Kite: Research Funding; Forty Seven: Research Funding; Genentech: Research Funding; Gilead: Research Funding; Celgene: Research Funding; Verastem: Consultancy, Research Funding; Incyte: Research Funding; Janssen: Research Funding; Takeda: Research Funding; TG Therapeutics: Research Funding; Pharmacyclics: Research Funding; Pfizer: Research Funding; Trillium: Research Funding; Novartis: Research Funding; Calithera: Research Funding; Constellation: Research Funding. Montillo:Roche: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria, Speakers Bureau; Gilead: Consultancy, Honoraria, Speakers Bureau. Davids:BMS: Research Funding; TG Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy; Merck: Consultancy; Surface Oncology: Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Verastem: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; MEI Pharma: Consultancy, Research Funding; Roche/Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie, Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees. Le:Verastem Oncology: Employment. Lustgarten:Verastem Oncology: Employment.

Introduction In CLL, the timing and selection of therapy is largely informed by disease stage, prognostic molecular features, tumor load, and patient (pt) performance status. Duvelisib (DUV) is a novel, oral, dual PI3K-δ,γ inhibitor in clinical development for the treatment of CLL/SLL, FL, and other hematologic malignancies. Results from the Phase 3 DUO study (NCT02004522) for relapsed/refractory CLL/SLL showed that DUV monotherapy resulted in statistically significant improvement over ofatumumab (OFA) monotherapy for median progression-free survival (mPFS; 13.3 vs 9.9 months (mo); p Methods Of the 319 pts enrolled in the DUO study, 158 were treated with DUV and 155 with OFA. Tumor burden was assessed at baseline using target lymph node diameter and absolute lymphocyte count. Baseline blood samples from Cycle1 Day1 were analyzed for cytogenetic abnormalities (17p, 11q, 6q deletions; trisomy 12); immune cell counts by flow cytometry; and serum chemokine, cytokine, and serum factor levels. Univariate analysis of these markers was conducted for PFS and ORR. The statistically significant univariate markers were tested in a stepwise multivariate regression (MVR) model using binary high [H] or low [L] thresholds based on the median. Results Tumor Burden: The mPFS (in mo) for DUV monotherapy did not appear to be impacted by baseline tumor burden: high (n=20), 16.6; medium (n=88), 12.7; and low (n=47), 15.1. Across these tumor burden levels, DUV maintained its PFS advantage over OFA. Cytogenetics: DUV-treated pts with del(11q), a marker associated with poor CLL outcomes, had a longer mPFS (in mo) and ORR compared to pts without del(11q) (mPFS: 24.8, n=25 vs 12.7, n=81; HR 0.56, 95% CI [0.30,1.06]; ORR: 80.0% vs 69.1%, odds ratio, 0.56). In contrast, mPFS was shorter in OFA-treated del(11q) pts relative to those without this deletion (5.3, n=24 vs 11.3, n=71). Median PFS was significantly extended in the del(17p) subgroup for DUV vs OFA (16.6, n=27 vs 9.2, n=27; HR 0.42, [0.21,0.85]), and, to a lesser degree, in pts without del(17p) (13.1, n=83 vs 11.1, n=74; HR 0.55 [0.37,0.83]). For the 6 DUV pts with del(11q/17p), mPFS was 17.4 mo. A shorter mPFS was observed for DUV-treated pts with trisomy 12 compared with trisomy 12-negative pts (9.1, n=16 vs 16.5, n=73). For the 10 DUV pts with trisomy 12 as well as del(11q/17p), mPFS was more similar to the trisomy 12 group, at 9.1 mo. Immune cell profiles and serum factors: Several immune cell profiles correlated with longer mPFS (in mo) for DUV, including Treg (16.4H vs 12.9L, HR 0.69 [0.43,1.12]) and monocytes (15.1L vs 12.7H, HR 0.82 [0.54,1.24]). Baseline chemokine and serum factor levels associated with longer mPFS with DUV included CCL3 (22.1L vs 12.2H, HR 0.60 [0.37,0.99]), IL2RA (16.3L vs 11.6H, HR 0.73 [0.47,1.14]), and TNFα (16.6L vs 12.2H, HR 0.78 [0.49,1.24]). Multivariate regression model: The MVR model showed that the biomarker profile of trisomy 12-negative (HR -/+, 0.15), CCL22L (HR H/L, 2.23), TNFαL (HR H/L, 3.66), TregH (HR H/L, 0.31), and monocytesL (HR H/L, 2.45), was associated with longer PFS; TNFαL and TregH were the largest associations, with estimated 73% and 69% reductions in risk of progression or death, respectively. Similarly, stepwise models yielded TNFαL (odds ratio H/L, 0.37) and CXCL11H (odds ratio H/L, 2.99) as biomarkers for improvement in ORR. Based on these analyses, pts with TNFαL tend to have better efficacy profiles for PFS and/or ORR. Conclusions: DUV monotherapy was highly efficacious in CLL/SLL pts with markers of poor response, including high tumor burden, del(17p), and del(11q) as shown by univariate analyses of tumor burden, cytogenetics, immune cell profiles, and serum factors. Multivariate analyses revealed a biomarker profile of CCL22L, TNFαL, TregH, monocytesL, and trisomy 12-negative that correlated with improved mPFS and/or ORR. Additional analyses are underway to characterize the predicted PFS for the biomarker profile. Disclosures Brown: Verastem: Consultancy, Research Funding; Janssen: Consultancy; Morphosys: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Consultancy; Sun Pharmaceutical Industries: Research Funding; TG Therapeutics: Consultancy; Sunesis: Consultancy; Gilead: Consultancy, Research Funding; Roche/Genentech: Consultancy; Genentech: Consultancy; Celgene: Consultancy; Boehringer: Consultancy; Beigene: Membership on an entity's Board of Directors or advisory committees; Acerta / Astra-Zeneca: Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy; Invectys: Membership on an entity's Board of Directors or advisory committees; Loxo: Consultancy. Flinn:Novartis: Research Funding; Merck: Research Funding; Infinity: Research Funding; Forty Seven: Research Funding; Janssen: Research Funding; Trillium: Research Funding; Pharmacyclics: Research Funding; Verastem: Research Funding; Pfizer: Research Funding; Kite: Research Funding; Takeda: Research Funding; Forma: Research Funding; BeiGene: Research Funding; Curis: Research Funding; Seattle Genetics: Research Funding; TG Therapeutics: Research Funding; Verastem: Consultancy, Research Funding; Portola: Research Funding; Calithera: Research Funding; ArQule: Research Funding; Celgene: Research Funding; Constellation: Research Funding; Genentech: Research Funding; Incyte: Research Funding; Gilead: Research Funding; Agios: Research Funding. Davids:Surface Oncology: Research Funding; Merck: Consultancy; Roche/Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees; AbbVie, Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; MEI Pharma: Consultancy, Research Funding; Verastem: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Research Funding; TG Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Hillmen:F. Hoffmann-La Roche Ltd: Research Funding; Celgene: Research Funding; Alexion Pharmaceuticals, Inc: Consultancy, Honoraria; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead Sciences, Inc.: Honoraria, Research Funding; Pharmacyclics: Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Acerta: Membership on an entity's Board of Directors or advisory committees. Montillo:Gilead: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria; Roche: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Speakers Bureau. Tam:Janssen: Consultancy, Honoraria, Research Funding; Pharmacyclics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; BeiGene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Jaeger:GSK: Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AOP Orphan: Membership on an entity's Board of Directors or advisory committees; Bioverativ: Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda-Millenium: Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda-Millenium: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy, Honoraria; Infinity: Membership on an entity's Board of Directors or advisory committees; Mundipharma: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; MSD: Research Funding. Ghia:Sunesis: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; BeiGene: Honoraria, Research Funding; Acerta: Honoraria, Research Funding; Gilead: Honoraria, Research Funding; AbbVie, Inc: Honoraria, Research Funding. Stilgenbauer:Genzyme: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Boehringer-Ingelheim: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; GSK: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmcyclics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Hoffmann La-Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Mundipharma: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Moreno:Janssen: Consultancy; AbbVie: Consultancy; Pharmacyclics LLC, an AbbVie Company: Consultancy. Le:Verastem Oncology: Employment. Lustgarten:Verastem Oncology: Employment. Sprott:Verastem Oncology: Employment. Pachter:Verastem Inc: Employment, Other: Stockholder. Weaver:Agios Pharmaceuticals: Employment; Verastem Oncology: Employment, Other: Stockholder; Femto Dx: Equity Ownership.

Background: Duvelisib (DUV), an oral, first-in-class dual inhibitor of PI3K-δ,-γ, is being developed for the treatment of hematologic malignancies, including relapsed/refractory (RR) CLL/SLL. In the Phase 3 DUO study (NCT02004522) DUV monotherapy demonstrated a significant improvement in efficacy compared to ofatumumab (OFA) monotherapy (median PFS [mPFS] 13.3 vs 9.9 mo., p Methods: Eligible pts enrolled within 3 months of PD on the DUO study (excluding Richter's transformation or prolymphocytic leukemia). DUV 25 mg BID was administered until PD, intolerance, death, or study withdrawal. Responses were determined by investigators per IWCLL (Cheson 2011)/IWG criteria (Cheson 2007) with modification for treatment-related lymphocytosis. Results: As of 15 June 2018, 90 pts crossed over from OFA on the DUO Study to receive DUV monotherapy 25 mg BID on Study IPI-145-12. At the initial study entry (DUO) the median age was 68 yrs (range: 39-89); 63% were male; and 90% Caucasian. Nearly half (49%) of the pts had Rai Stage III/IV or Binet Stage C, and 23% had del(17p) and/or TP53 mutation. The median number of prior anticancer therapies was 3 (range: 2-8), with 60% of pts having received ≥ 3 prior anticancer therapies. 90 of the 101 pts treated with OFA on DUO who had PD crossed over to receive DUV. The median exposure to OFA for these 90 pts was 23 weeks (range: 1-26 weeks), with 61% receiving all 12 prescribed infusions. Post-crossover, the median exposure to DUV was 43 weeks (range: 2-170 weeks). Table 1 shows the overall response rate for the same pt set pre-crossover on OFA and post-crossover on DUV. The mPFS on DUV post-crossover was 15 months (95% CI: 12, 20) compared to a mPFS of 9 months (95% CI: 9, 11) on OFA pre-crossover. This difference was even more pronounced in pts with del(17p) (n=20), who had a mPFS of 17 months (95% CI: 9, 21) on DUV post-crossover compared to a mPFS of 8 months (95% CI: 5, 11) on OFA pre-crossover. The ORR on DUV post-crossover was 77% compared to 29% on OFA pre-crossover, and in the subset of pts with del(17p) was 80% on DUV vs 15% on OFA. In the subset of pts (n=47) who had no response on OFA pre-crossover (SD/PD), the ORR post-crossover on DUV was 73%. Pts on DUV achieved rapid lymphocytosis (median 1.1 months) with a median time to first response of 2.6 months (i.e., first response assessment). The most common severe (≥ Gr 3) hematologic AEs on DUV included neutropenia (23%) and thrombocytopenia (4%). The most common severe non-hematologic AEs included diarrhea (21%), pneumonia (12%), colitis (11%), lipase increased (7%), acute renal failure (6%), and bronchitis, rash, and sepsis (4%, each). Nine pts had AEs with a fatal outcome with 1 assessed as related to treatment (PJP). Approximately 70% of pts had a dose modification (interruption and/or reduction) due to an AE, with the most common (>5%) being diarrhea (27%), pneumonia (10%), colitis (8%), neutropenia and lipase increased (7% each). AEs leading to treatment discontinuation (≥ 2 pts) included colitis (n=9; 10%), diarrhea (n=8; 9%), pneumonia (n=2; 2%), and rash (n=2; 2%). Seventy-three pts (81%) have discontinued DUV on Study IPI-145-12, 39 (43%) due to AEs, 19 (21%) due to PD, 6 (7%) due to death, 5 (6%) due to voluntary withdrawal/investigator decision, and 4 (4%) for other reasons; 17 (19%) pts remain on DUV. Conclusions: DUV monotherapy achieved robust and durable responses (ORR 77%, mPFS 15 months) in pts with RR CLL/SLL who had PD following OFA monotherapy on the DUO study, including pts with del(17p) (ORR 80%). DUV also showed strong activity (ORR 73%) in pts who had no prior response on OFA. Response on DUV was rapid, with a median time to lymphocytosis of ~ 1 month and a median time to response of ~2 months (first response assessment). The safety profile of DUV monotherapy in this crossover study was manageable and similar to that observed with DUV monotherapy on the DUO study. These data further support the potential clinical benefit of DUV monotherapy in pts with RR CLL/SLL. Disclosures Davids: Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; TG Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie, Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; MEI Pharma: Consultancy, Research Funding; Surface Oncology: Research Funding; Merck: Consultancy; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy; Verastem: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche/Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Research Funding. Hillmen:Alexion Pharmaceuticals, Inc: Consultancy, Honoraria; Pharmacyclics: Research Funding; F. Hoffmann-La Roche Ltd: Research Funding; Gilead Sciences, Inc.: Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Acerta: Membership on an entity's Board of Directors or advisory committees; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Research Funding. Montillo:Roche: Consultancy, Honoraria, Research Funding; Gilead: Consultancy, Honoraria, Speakers Bureau; AbbVie: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria. Lamanna:TG Therapeutics: Research Funding; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Jannsen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Acerta: Research Funding; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Verastem: Research Funding. Tam:Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Pharmacyclics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; BeiGene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Honoraria, Research Funding. Stilgenbauer:Mundipharma: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Hoffmann La-Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmcyclics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Boehringer-Ingelheim: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Genzyme: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; GSK: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Ghia:Acerta: Honoraria, Research Funding; BeiGene: Honoraria, Research Funding; Sunesis: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; AbbVie, Inc: Honoraria, Research Funding; Gilead: Honoraria, Research Funding; Janssen: Honoraria, Research Funding. Le:Verastem Oncology: Employment. Lustgarten:Verastem Oncology: Employment. Weaver:Verastem Oncology: Employment, Other: Stockholder; Femto Dx: Equity Ownership; Agios Pharmaceuticals: Employment. Jaeger:Takeda-Millenium: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Consultancy, Honoraria; Infinity: Membership on an entity's Board of Directors or advisory committees; Mundipharma: Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda-Millenium: Membership on an entity's Board of Directors or advisory committees; Bioverativ: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; AOP Orphan: Membership on an entity's Board of Directors or advisory committees; GSK: Membership on an entity's Board of Directors or advisory committees; MSD: Research Funding.

Aims This phase I dose-escalation study was designed to evaluate the combination of the mammalian target of rapamycin inhibitor ridaforolimus with the vascular endothelial growth factor inhibitor bevacizumab. Materials and methods Seventeen adult patients with refractory advanced solid tumours received oral ridaforolimus (30 or 40 mg) once daily for 5 days per week (QDx5/wk) combined with intravenous bevacizumab (10 mg/kg every 2 weeks [Q2wk] or 15 mg/kg every 3 weeks [Q3wk]). Patients were evaluated for dose-limiting toxicities, safety and anti-tumour activity. Results A 40 mg dose of ridaforolimus with either bevacizumab dosing schedule was the recommended phase II dose. No dose-limiting toxicities were reported; the most common drug-related adverse events were mucosal inflammation and anorexia. Seven patients, with clinical features that included primary tumour of the abdominal origin (colorectal, pancreatic or gynaecological cancers) and previous abdominal radiotherapy, reported serious adverse events related to bowel perforations. There were no objective responses, but 65% of patients had a best response of stable disease. Conclusion Oral ridaforolimus (40 mg QDx5/wk) is feasible to combine with standard doses of bevacizumab, although careful patient selection would be needed to mitigate the risk of bowel perforation-related adverse events. Combination therapy produced prolonged stable disease in several heavily pretreated patients.

Activating mutations in the FMS-like tyrosine kinase-3 (FLT3), a tyrosine kinase receptor important in haematopoiesis, are among the most common molecular aberrations in acute myeloid leukaemia (AML), occurring in 30% of adult patients (Levis & Small 2003). Common FLT3-activating mutations include FLT3 internal tandem duplications (FLT3-ITDs), detected in about 23% of AML patients, and point mutations within the tyrosine kinase domain, found in about 8% (Levis & Small 2003). These mutations result in a constitutively active FLT3 receptor, leading to growth factor–independent proliferation and survival of leukaemic cells and conferring poor prognosis (Levis & Small 2003). Clinical studies of single-agent first-generation FLT3 inhibitors have demonstrated clinical activity, with responses that are typically short-lived and mostly partial or complete responses with incomplete haematopoietic recovery. This may be due to suboptimal potency and/or pharmacokinetics, leading to insufficient or transient target inhibition, or concomitant c-kit inhibition (Knapper 2011). Recently, high potency second-generation FLT3 inhibitors (eg, quizartinib) have shown substantial efficacy as monotherapy, suggesting a potency threshold for clinical benefit (Knapper 2011). The validation of FLT3-ITD as a therapeutic target has rekindled interest in developing and testing new potent FLT3 inhibitors in AML patients with FLT3-ITD mutations (Smith et al, 2012). Ponatinib is a novel, orally administered tyrosine kinase inhibitor (TKI) and a potent pan–BCR-ABL1 inhibitor (O’Hare et al, 2009). Based on results in patients with chronic myeloid leukaemia (CML) and Philadelphia chromosome–positive acute lymphoblastic leukaemia (Ph+ ALL) in phase 1 and phase 2 clinical trials (Cortes et al 2012a, Cortes et al (2012b), ponatinib (45 mg once daily) has been approved in the United States for the treatment of patients with CML and Ph+ ALL that is resistant or intolerant to prior TKI therapy. Preclinical studies revealed that ponatinib also potently inhibits FLT3, leading to apoptosis of leukaemic cell lines carrying the FLT3-ITD mutation and tumour regression in xenograft models, suggesting the potential for activity in patients with AML (Gozgit et al, 2011). Additionally, ponatinib appears to retain activity against the clinically-relevant quizartinib-resistant mutant FLT3-ITD F691L (Smith et al, 2013). Here we report the first clinical experience with ponatinib in 12 AML patients included in the phase 1 study. Methods are described in the on-line supporting information. The median age of these patients was 49 (30-72) years. The median time from diagnosis to treatment was 1 year. Patients received a median of 3 (1-7) prior therapies; 58% had received 3 or more prior therapies (Table I and Table S1). Mutational analysis in a central laboratory confirmed the presence of FLT3-ITD in 7 patients (58%). Three additional patients did not have an adequate DNA sample at study entry; however, they had a history of FLT3-ITD mutation—as reported by the investigator—and they are included in the FLT3-ITD mutation– positive group for these analyses. Three patients (all FLT3-ITD mutation positive) were previously treated with one or more FLT3 inhibitors (sorafenib, quizartinib, and/or IMC-EB10); one patient progressed on IMC-EB10 and had a partial response to sorafenib, one patient had a complete response to sorafenib and a partial response to quizartinib, and one patient had a partial response to quizartinib. Seven patients (70%) with FLT3-ITD mutation were FLT3 inhibitor– naive (Table I). The median treatment duration was 52 (10-173) days. At the time of analysis, all patients had discontinued ponatinib: 5 (42%) due to death (all unrelated to ponatinib), 3 (25%) due to adverse events (AEs: unrelated central nervous system [CNS] haemorrhage, possibly related acute pancreatitis, unrelated graft vs host disease), 2 (17%) due to progressive disease (PD), and 2 (17%) due to investigator decision (Table I). Table 1 Selected baseline characteristics, treatment duration, response, and reasons for discontinuation by individual patients with AML Nine patients experienced at least one treatment-related AE. The most common treatment-related AEs occurring in 2 or more patients were pancreatitis (n=3) and petechiae (n=2). Three patients experienced a treatment-related serious AE (SAE) of pancreatitis (all grade 2), which was a dose-limiting toxicity in this trial (Cortes et al, 2012a). Pancreatitis resolved in 2 patients after dose interruption, lasting 3 days in one patient and 8 days in the other. These 2 patients continued therapy at a reduced dose (30 mg) and were subsequently re-escalated to 45 mg without recurrence. The third patient discontinued therapy per investigator decision. Additional details regarding treatment-emergent AEs and SAEs can be found in Table S2. Seven patients died during the study for reasons not related to ponatinib: disease progression (n=3), multiorgan failure (n=2), pneumonia and sepsis (n=1), and CNS haemorrhage (n=1) (Table I). Ponatinib had an acceptable safety profile in this small group of patients with refractory AML, similar to that observed in patients with CML and Ph+ ALL. Few treatment-related AEs were reported; the most common was pancreatitis, which was manageable, and re-challenge with ponatinib was possible in most cases. The geometric mean maximal concentration and area under the curve of single-dose ponatinib at day 1, cycle 1 in AML patients were 97 nM and 1441 nM*h, respectively, similar to findings across all 31 patients receiving 45 mg ponatinib (98.8 nM and 1360.1 nM*h). The overall response rate (RR, partial remission or better) was 3/12 (25%): 2 patients achieved complete remission with incomplete blood count recovery and one patient experienced partial remission (Table I, Fig 1). These 3 responders carried FLT3-ITD mutations and were all FLT3 inhibitor–naive; the duration of ponatinib treatment in these patients was 3 to 6 months. Among 10 patients with FLT3-ITD mutations, RR was 3/10 (30%). Among 7 patients with FLT3-ITD mutations who were FLT3 inhibitor–naive, RR was 3/7 (43%). Three patients (2 FLT3-ITD negative) had stable disease, as they did not meet criteria for complete/partial remission or PD; however, peripheral blood blasts in 2 of these patients decreased considerably (~60-90%) during the first treatment cycle. The RR reported with quizartinib in phase 1 testing was 30% (Cortes et al, 2009) and 10% with sorafenib (Borthakur et al, 2011). Although the sample size reported here is small, these results suggest that ponatinib has clinical activity in AML patients with FLT3-ITD, requiring confirmation in a larger cohort of patients and with additional focus on optimization of response (eg, combination therapy) and response durability. Figure 1 Course of the disease in 3 responders during ponatinib treatment

Summary Background Ponatinib has shown potent activity against chronic myeloid leukaemia that is resistant to available treatment, although it is associated with arterial occlusion. We investigated whether this activity and safety profile would result in superior outcomes compared with imatinib in previously untreated patients with chronic myeloid leukaemia. Methods The Evaluation of Ponatinib versus Imatinib in Chronic Myeloid Leukemia (EPIC) study was a randomised, open-label, phase 3 trial designed to assess the efficacy and safety of ponatinib, compared with imatinib, in newly diagnosed patients with chronic-phase chronic myeloid leukaemia. Patients from 106 centres in 21 countries were randomly assigned (1:1, with stratification by Sokal score at diagnosis) using an interactive voice and web response system to receive oral ponatinib (45 mg) or imatinib (400 mg) once daily until progression, unacceptable toxicity, or other criteria for withdrawal were met. Eligible patients were at least 18 years of age, within 6 months of diagnosis, and Philadelphia chromosome-positive by cytogenetic assessment, with Eastern Cooperative Oncology Group performance status of 0–2, and had not previously been treated with tyrosine kinase inhibitors. The primary endpoint was major molecular response at 12 months. Patients who remained on study and had molecular assessments at specified timepoints were studied at those timepoints. Safety analyses included all treated patients, as per study protocol. This trial is registered with ClinicalTrials.gov, number NCT01650805. Findings Between Aug 14, 2012, and Oct 9, 2013, 307 patients were randomly assigned to receive ponatinib (n=155) or imatinib (n=152). The trial was terminated early, on Oct 17, 2013, following concerns about vascular adverse events observed in patients given ponatinib in other trials. Trial termination limited assessment of the primary endpoint of major molecular response at 12 months, as only 13 patients in the imatinib group and ten patients in the ponatinib group could be assessed at this timepoint; the proportion of patients achieving a major molecular response at 12 months did not differ significantly between the two groups (eight [80%] of ten patients given ponatinib and five [38%] of 13 patients given imatinib; p=0·074). 11 (7%) of 154 patients given ponatinib and three (2%) of 152 patients given imatinib had arterial occlusive events (p=0·052); arterial occlusive events were designated serious in ten (6%) of 154 patients given ponatinib and in one (1%) of 152 patients given imatinib (p=0·010). The data monitoring committee criterion for risk assessment (significant difference in serious grade 3 or 4 ischaemic events between groups) was not met (five [3%] of 154 vs one [1%] of 152; p=0·21). Grade 3 or 4 adverse events observed in more than 5% of patients in the ponatinib group were increased lipase (22 [14%] of 154 vs three [2%] of 152 with imatinib), thrombocytopenia (19 [12%] of 154 vs ten [7%] of 152 with imatinib), rash (ten [6%] of 154 vs two [1%] of 152 with imatinib). In the imatinib group, grade 3 or 4 adverse events observed in more than 5% of patients were neutropenia (12 [8%] of 152 vs five [3%] of 154 with ponatinib) and thrombocytopenia (ten [7%] of 152 vs 19 [12%] of 154 with ponatinib). Serious adverse events that occurred in three or more patients given ponatinib were pancreatitis (n=5), atrial fibrillation (n=3), and thrombocytopenia (n=3). No serious adverse event occurred in three or more patients given imatinib. Interpretation The efficacy of ponatinib treatment of newly diagnosed chronic-phase chronic myeloid leukaemia compared with imatinib could not be assessed due to trial termination, but preliminary data suggest there might be benefit, although with more arterial occlusive events than with imatinib at the doses studied. Because the EPIC trial was terminated early, efficacy of ponatinib in this setting remains to be established. Funding ARIAD Pharmaceuticals.

BCR-ABL1 kinase domain mutations can confer resistance to first- and second-generation tyrosine kinase inhibitors (TKIs) in chronic myeloid leukemia (CML). In preclinical studies, clinically achievable concentrations of the third-generation BCR-ABL1 TKI ponatinib inhibit T315I and all other single BCR-ABL1 mutants except T315M, which generates a single amino acid exchange, but requires 2 sequential nucleotide exchanges. In addition, certain compound mutants (containingmutations in cis) confer resistance. Initial analyses based largely on conventional Sanger sequencing (SS) have suggested that the preclinical relationship between BCR-ABL1 mutation status and ponatinib efficacy is generally recapitulated in patients receiving therapy. Thus far, however, such analyses have been limited by the inability of SS to definitively identify compound mutations or mutations representing less than ∼20%of total alleles (referred to as "low-level mutations"), as well as limited patient follow-up. Here we used next-generation sequencing (NGS) to define the baseline BCR-ABL1 mutation status of 267 heavily pretreated chronic phase (CP)-CML patients from the PACE trial, and used SS to identify clonally dominant mutants that may have developed on ponatinib therapy (30.1 months median follow-up). Durable cytogenetic and molecular responses were observed irrespective of baseline mutation status and included patients with compound mutations. No single or compound mutation was identified that consistently conferred primary and/or secondary resistance to ponatinib in CP-CML patients. Ponatinib is effective in CP-CML irrespective of baseline mutation status. Refereed/Peer-reviewed

To evaluate the association of efavirenz hypersusceptibility (EFV-HS) with clinical outcome in a double-blind, placebo-controlled, randomized trial of EFV plus indinavir (EFV+IDV) vs. EFV+IDV plus abacavir (ABC) in 283 nucleoside-experienced HIV-infected patients.Rates of virologic failure were similar in the 2 arms at week 16 (p = .509). Treatment discontinuations were more common in the ABC arm (p = .001). Using logistic regression, there was no association between virologic failure and either baseline ABC resistance or regimen sensitivity score. Using 3 different genotypic scoring systems, EFV-HS was significantly associated with reduced virologic failure at week 16, independent of treatment assignment. In some patients on the nucleoside-sparing arm, the nucleoside-resistance mutation L74V was selected for in combination with the uncommonly occurring EFV-resistance mutations K103N+L100I; L74V was not detected as a minority variant, using clonal sequence analysis, when the nucleoside-sparing regimen was initiated.Premature treatment discontinuations in the ABC arm and the presence of EFV-HS HIV variants in this patient population likely made it difficult to detect a benefit of adding ABC to EFV+IDV. In addition, L74V, when combined with K103N+L100I, may confer a selective advantage to the virus that is independent of its effects on nucleoside resistance.

Interferon alfa is widely used for metastatic renal-cell carcinoma but has limited efficacy and tolerability. Temsirolimus, a specific inhibitor of the mammalian target of rapamycin kinase, may benefit patients with this disease.In this multicenter, phase 3 trial, we randomly assigned 626 patients with previously untreated, poor-prognosis metastatic renal-cell carcinoma to receive 25 mg of intravenous temsirolimus weekly, 3 million U of interferon alfa (with an increase to 18 million U) subcutaneously three times weekly, or combination therapy with 15 mg of temsirolimus weekly plus 6 million U of interferon alfa three times weekly. The primary end point was overall survival in comparisons of the temsirolimus group and the combination-therapy group with the interferon group.Patients who received temsirolimus alone had longer overall survival (hazard ratio for death, 0.73; 95% confidence interval [CI], 0.58 to 0.92; P=0.008) and progression-free survival (P0.001) than did patients who received interferon alone. Overall survival in the combination-therapy group did not differ significantly from that in the interferon group (hazard ratio, 0.96; 95% CI, 0.76 to 1.20; P=0.70). Median overall survival times in the interferon group, the temsirolimus group, and the combination-therapy group were 7.3, 10.9, and 8.4 months, respectively. Rash, peripheral edema, hyperglycemia, and hyperlipidemia were more common in the temsirolimus group, whereas asthenia was more common in the interferon group. There were fewer patients with serious adverse events in the temsirolimus group than in the interferon group (P=0.02).As compared with interferon alfa, temsirolimus improved overall survival among patients with metastatic renal-cell carcinoma and a poor prognosis. The addition of temsirolimus to interferon did not improve survival. (ClinicalTrials.gov number, NCT00065468 [ClinicalTrials.gov].).

7050 Background: Ponatinib is approved for pts with refractory CML or Ph+ ALL for whom no other TKI therapy is indicated, or for patients with T315I. Previously (Mueller ASCO ‘16), we reported the positive association of early landmark responses with ponatinib on survival at 3 yrs in heavily pretreated pts with CP-CML in PACE (NCT01207440). Here, we provide an update with survival outcomes at 4 yrs. Methods: The association of molecular (assessed in a central lab) and cytogenetic responses (CyR) at 3, 6 and 12 mo with 4-yr post-landmark PFS and OS was evaluated in CP-CML pts (n = 267). P values: calculated using log-rank test. Data cutoff: 3 Oct ‘16. Results: At baseline, median time from diagnosis: 7 (range, 0.5–27) yrs; median age: 60 (18–94) yrs; median %Ph+: 100% (3–100), ≤10% Ph+: 19 pts (7%); 61% of pts had ≥3 prior TKIs. Among evaluable pts at 3, 6 and 12 mo, MCyR/CCyR was achieved in 48%/39%, 62%/52% and 71%/56% and MMR in 14%, 29% and 39% of pts, respectively. Greater reductions in BCR-ABL1 levels (Table) and CyR at most landmark time points were associated with improved 4-yr post-landmark PFS and OS. Deeper responses at all landmark time points were associated with achievement of MR4.5 over time. Conclusions: As with the 3-yr landmark analysis, CyR and deep reductions in BCR-ABL1 transcripts at early time points correlated with improved 4-yr post-landmark survival in this refractory population. These data continue to demonstrate the prognostic value of early cytogenetic and molecular responses with ponatinib in heavily pretreated pts with CP-CML. Clinical trial information: NCT01207440. [Table: see text]

TPS7073 Background: Ponatinib is an oral TKI with potent activity against BCR-ABL1. The pivotal PACE study (NCT01207440) formed the basis for approval of ponatinib in the US for the treatment of patients with resistant/intolerant CML or Ph+ ALL, or those with the T315I mutation. Long-term follow-up of PACE showed a higher cumulative incidence of vascular occlusive events (VOEs) than reported at the time of approval — dose reductions were later implemented to mitigate VOEs. VOEs comprise arterial occlusive events (AOE) and venous thromboembolic events. The exposure-adjusted incidence of AOEs has not increased over time in PACE; in patients with a history of ischemic disease, the relative risk of serious AOEs was 2.6 in those with ≥2 vs 0 risk factors. The primary objective of this patient registry is to assess VOEs occurring during ponatinib use in routine clinical practice in the US. Methods: OMNI (NCT02455024) is a prospective observational registry of eligible patients (Table) with CML or Ph+ ALL for whom the decision to initiate treatment with ponatinib has already been made for the approved US indications. Patients voluntarily enroll into the registry, which is non-interventional with no protocol-mandated tests/procedures — all treatment decisions are made at the discretion of the health care practitioner in consultation with their patient. Study duration is anticipated as ~30 mo (~18-mo enrollment followed by 12 mo of data collection, which will occur every 3 mo). The primary analysis will be performed 12 mo after last patient enrolled and will estimate the incidence of VOEs by duration of ponatinib exposure. To understand differences between those with and without VOEs, exploratory analyses will be performed, considering factors such as patient demographics, risk factors for developing VOEs, dose and duration of ponatinib treatment, and concomitant medications. VOE outcomes also will be assessed. Enrollment will begin in 2017, with a target of ≥300 patients. Clinical trial information: NCT02455024. [Table: see text]

In trials with failure-time outcomes, statistical information is determined by accumulated events. Interim and final analyses are performed after a prespecified number of events have been observed. It is of interest to predict when a prespecified number of events will be observed based on accumulating data. We propose a fully Bayesian nonparametric approach in modeling the survival probabilities. We compare the accuracy and precision of this approach to proposed parametric and semi-parametric methods. In summary, the proposed method offers greater flexibility and based on our studies has the ability to match or outperform existing methods.

Background: Ponatinib, an oral tyrosine kinase inhibitor with potent activity against native and mutant BCR-ABL1, is approved for patients with refractory chronic myeloid leukemia (CML) or Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) for whom no other tyrosine kinase inhibitor (TKI) therapy is indicated, or for patients with the T315I mutation. The efficacy and safety of ponatinib in patients with resistant/refractory hematologic malignancies were evaluated in a phase 1 trial (NCT00660920). Here, we report 4-year follow-up data from chronic-phase (CP)-CML patients; final data (approximately 5-year follow-up) will be presented. Methods: In this open-label, dose-escalation, phase 1 trial, 81 patients with resistant/refractory hematologic malignancies (CP-CML, 43 patients; accelerated-phase CML, 9 patients; blast-phase CML, 8 patients; Ph+ ALL, 5 patients) were enrolled. Patients were treated with ponatinib at a starting dose of 2 mg/d - 60 mg/d; intra-patient dose escalation was permitted. In Oct 2013, dose reduction instructions were provided in response to an observed accumulation of arterial occlusive events (AOEs) with longer follow-up across the ponatinib clinical program. For data presented herein, the data cutoff date is 2 Feb 2015, with median follow-up of 53.1 months (range, 1.7 - 69.9 months) for CP-CML patients. Results: Among CP-CML patients, at baseline, median age was 55 years and median time since diagnosis was 6.6 years; BCR-ABL1 kinase domain mutations were reported in 63% of patients, with T315I confirmed at a central laboratory in 28% of patients. Patients were heavily pretreated, with 37% having received 2 prior TKIs and 60% having received ≥3 prior TKIs. Of 43 CP-CML patients, 22 (51%) remained on ponatinib treatment at data cutoff. Adverse events (AEs; 26%) and disease progression (9%) were the most common reasons for discontinuation of treatment. Cumulative response rates were: major cytogenetic response (MCyR), 72%; complete cytogenetic response (CCyR), 65%; major molecular response (MMR; assessed at a central laboratory), 56%; molecular response 4 (MR4), 42%; MR4.5, 28%. Responses were durable (Table), with median durations of response not reached for MCyR, CCyR, and MMR. Among patients who received ponatinib at starting doses of ≤30 mg/d (n = 15), MCyR was achieved by 67%, CCyR by 53%, and MMR by 47%; ponatinib dose was ≤30 mg/d in all but one of these patients at the time of response. Of 19 patients who were ongoing and in MCyR as of Oct 2013, 13 had their dose reduced; all 13 dose-reduced patients maintained MCyR at data cutoff. Of the 22 ongoing patients at the time of the present analysis, 18 (82%) had CCyR and 17 (77%) had MMR or better (MMR, 6 patients; MR4, 1 patient; MR4.5, 9 patients; MR5, 1 patient) as their response at the data cutoff; 14/22 (64%) ongoing patients were receiving 15 mg/d as their current dose as of the data cutoff. Rash (65%), fatigue (63%), abdominal pain (58%), headache (58%) and arthralgia (53%) were the most common treatment-emergent AEs. The incidence of AOEs (any/serious) was 40%/30% (by subcategory: cardiovascular, 30%/21%; cerebrovascular, 9%/7%; peripheral vascular, 14%/9%). Conclusions: With median follow-up of over 4 years in this phase 1 study, ponatinib continues to provide clinical benefit to heavily pre-treated CP-CML patients, approximately half of whom continue to receive ponatinib, with a majority in deep response that has been long-lasting; final study data will be presented. The most common treatment-emergent AEs were consistent with the AE profile across the clinical program. Potential for long-term benefit, demonstrated herein, versus risk should be considered when using ponatinib in this patient population. Study sponsor: ARIAD Pharmaceuticals, Inc. Disclosures Mauro: BMS: Consultancy, Honoraria; ARIAD: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria. Cortes:ARIAD: Consultancy, Research Funding; Bristol-Myers Squib: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Teva: Research Funding. Kantarjian:Bristol-Myers Squibb: Research Funding; Amgen: Research Funding; ARIAD: Research Funding; Pfizer Inc: Research Funding; Delta-Fly Pharma: Research Funding; Novartis: Research Funding. Shah:ARIAD: Research Funding; BMS: Research Funding; Daiichi-Sankyo: Research Funding; Pfizer: Research Funding; Plexxikon: Research Funding. Flinn:Janssen: Research Funding; Pharmacyclics LLC, an AbbVie Company: Research Funding; Gilead Sciences: Research Funding; ARIAD: Research Funding; RainTree Oncology Services: Equity Ownership. Rivera:ARIAD: Employment, Equity Ownership. Lustgarten:ARIAD: Employment, Equity Ownership. Santillana:ARIAD: Employment, Equity Ownership. Heinrich:Novartis: Consultancy, Patents & Royalties, Research Funding; Pfizer: Consultancy; Bayer: Research Funding; BMS: Research Funding; Blueprint Medicines: Consultancy; MolecularMD: Consultancy, Equity Ownership; ARIAD: Consultancy, Research Funding; Onyx: Consultancy. Druker:Agios: Honoraria; Ambit BioSciences: Consultancy; ARIAD: Patents & Royalties, Research Funding; Array: Patents & Royalties; AstraZeneca: Consultancy; Blueprint Medicines: Consultancy, Equity Ownership, Other: travel, accommodations, expenses ; BMS: Research Funding; CTI: Equity Ownership; Curis: Patents & Royalties; Cylene: Consultancy, Equity Ownership; D3 Oncology Solutions: Consultancy; Gilead Sciences: Consultancy, Other: travel, accommodations, expenses ; Lorus: Consultancy, Equity Ownership; MolecularMD: Consultancy, Equity Ownership, Patents & Royalties; Novartis: Research Funding; Oncotide Pharmaceuticals: Research Funding; Pfizer: Patents & Royalties; Roche: Consultancy. Deininger:Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Research Funding; Incyte: Consultancy, Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy, Research Funding; CTI BioPharma Corp.: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding; Bristol Myers Squibb: Consultancy, Research Funding; Ariad: Consultancy, Membership on an entity's Board of Directors or advisory committees. Talpaz:Novartis: Research Funding; Incyte Corporation: Other: Travel expense reimbursement, Research Funding; Ariad: Other: Expense reimbursement, travel accomodation expenses, Research Funding; Pfizer: Consultancy, Other: travel accomodation expenses, Research Funding.

Background: Ponatinib is a tyrosine kinase inhibitor (TKI) with potent activity against BCR-ABL1 and all single resistance mutants. In the Phase 2 PACE study (NCT01207440), ponatinib induced high rates of major hematological response (MaHR) and major cytogenetic response (MCyR) in BP-CML (31% and 23%) and Ph+ ALL (41% and 47%) patients (pts), even though 91% of pts had received at least 2 prior TKIs. However, the median progression free survival was only 4 months for BP-CML and 3 months for Ph+ ALL (Cortes JE, et al. N Engl J Med 2013). Previous studies have shown that certain compound mutations can cause resistance to ponatinib (Zabriskie et al. Cancer Cell 2014), but such mutations were found to be extremely rare in CP-CML pts from the PACE trial despite being heavily pre-treated (Deininger MW, et al. Blood 2016). Here we utilize a multi-level sequencing strategy that combines Sanger Sequencing (SS), Next Generation Sequencing (NGS), and single molecule Duplex Sequencing (DS), which is orders of magnitude more sensitive than NGS, to profile the mutational mechanisms that may account for the survival outcomes observed in BP-CML/Ph+ ALL pts treated with ponatinib in PACE. Methods: The BCR-ABL1 mutation status of the 267 CP-CML, 62 BP-CML, and 32 Ph+ ALL pts treated in the PACE trial was examined using SS and/or NGS as described previously (Cortes JE, et al. N Engl J Med 2013; Deininger MW, et al. Blood 2016). Mutations detected by SS at the end of treatment (EOT) but not at baseline (BL) were considered to have been gained during ponatinib treatment. DS was performed to determine whether mutations gained on treatment could be found in small sub-populations of cells at BL and to provide a direct measurement of the mutation burden in the ABL1 gene. Two distinct mathematical models were used to predict the size of pre-existing resistant sub-populations in BP-CML/Ph+ ALL pts based on the overall ABL1 mutation burden and the doubling time of clonal outgrowth. Results: The number of BCR-ABL1 mutations in BP-CML/Ph+ ALL patients at BL, as detected by SS, was not a significant predictor of intrinsic resistance to ponatinib in refractory patients with Odds Ratios (OR) of 1.0 (0.2-4.9 95% CI) for MaHR and 2.4 (0.5-12.5 95% CI) for MCyR. However, a larger proportion of BP-CML/Ph+ ALL pts, 30/61, acquired mutations in BCR-ABL1 at EOT vs. 19/130 CP-CML pts (p Conclusions: Clonal BL BCR-ABL1 mutation status determined by SS does not predict intrinsic resistance to ponatinib. However, in contrast to CP-CML, BP-CML/Ph+ ALL pts are more likely to relapse on ponatinib with acquired mutations in BCR-ABL1. Two distinct mathematical modeling strategies suggest that most, if not all, BCR-ABL1 resistance mutations in BP-CML/Ph+ ALL pts that emerge during ponatinib treatment were pre-existing. The majority of these pre-existing mutations were compound mutations whose evolutionary path was likely determined by prior TKI therapy. These findings emphasize the risk of the large population expansions that occur following prior TKI treatment failure and may explain the relatively high 2-yr event free survival rate of 81% observed in previously untreated Ph+ ALL pts treated with ponatinib (+hyper-CVAD) (Jabbour E, et al. Lancet Oncol 2015, Sasaki, et al. Cancer 2016). Study sponsor: ARIAD Pharmaceuticals, Inc. Disclosures Pritchard: ARIAD: Employment, Equity Ownership. Schmitt:TwinStrand: Equity Ownership. Hodgson:ARIAD: Employment, Equity Ownership. Lustgarten:ARIAD: Employment, Equity Ownership. Tang:ARIAD: Employment, Equity Ownership. Loeb:TwinStrand: Equity Ownership. Radich:Novartis: Consultancy, Other: laboratory contract; Bristol-MyersSquibb: Consultancy; Pfizer: Consultancy; ARIAD: Consultancy; TwinStrand: Consultancy. Rivera:ARIAD: Employment, Equity Ownership.

Background: Ponatinib is a tyrosine kinase inhibitor (TKI) approved for adult patients (pts) with relapsed/refractory CML or Ph+ ALL and those with the BCR-ABL T315I mutation, which is uniformly resistant to other TKIs approved for the treatment of CML and Ph+ ALL. Prior to the availability of ponatinib, resistant pts with the T315I mutation (T315I+) had worse outcomes than those without the mutation; in a matched pair analysis in chronic phase (CP)-CML pts, median overall survival (OS) was 48.4 mos after development of resistance in T315I+ pts versus not reached in those without the mutation (Nicolini FE, et al. Haematologica 2013). Methods: We evaluated the efficacy and safety of ponatinib in a pooled analysis of a subgroup of CP-CML pts with the T315I mutation (detected in a central laboratory by Sanger sequencing at baseline) from the phase 1 (NCT00660920) and pivotal phase 2 PACE (NCT01207440) trials. In addition, we evaluated the impact of continuation of ponatinib treatment at a 2-yr landmark time point on OS at 1-yr past the landmark in T315I+ CP-CML pts in PACE. The phase 1 trial is an open-label, dose escalation study of ponatinib (starting dose 2-60 mg once daily) in 81 adults with relapsed/refractory hematologic malignancies. PACE is an open-label, single-arm trial of ponatinib (starting dose 45 mg daily) in 449 adults with CML or Ph+ ALL resistant or intolerant to dasatinib or nilotinib or with the T315I mutation. Dose reductions were instructed in Oct 2013 in response to an accumulation of arterial occlusive events (AOEs) reported with longer follow-up across the ponatinib clinical program. Response assessments included major cytogenetic response (MCyR), complete cytogenetic response (CCyR), major molecular response (MMR; assessed in a central laboratory), and molecular response 4.5 (MR4.5). OS and progression-free survival (PFS) data were only collected in PACE; 3-yr outcomes were examined for all evaluable T315I+ CP-CML pts, along with a log-rank test for OS by treatment status as of the 2-yr landmark time point. Exposure-adjusted incidence rates of new AOEs are reported as number of events/100 pt-yrs. Pooled data as of February 2, 2015 is reported here. Results: There were 76 T315I+ CP-CML pts included in this analysis (phase 1, n=12; PACE, n=64). At the time of analysis, median duration of follow-up in T315I+ CP-CML pts was 40 (range: 1.5-74) mos; 37 pts (49%) remain on study. Median baseline ponatinib dose intensity was 33 (range: 5-56) mg daily; 25/37 (68%) ongoing pts were receiving 15 mg daily as their current dose as of the data cut-off. Primary reasons for discontinuation in T315I+ CP-CML pts were disease progression [10/76 (13%)], adverse events [AEs; 9/76 (12%)], consent withdrawn [5/76 (7%)], physician/administrative decision [4/76 (5%)], death [3/76 (4%)], lack of efficacy [2/76 (3%)], and other [6/76 (8%)]; criteria for disease progression included death, development of advanced phase CML, loss of CHR (in absence of cytogenetic response) and loss of MCyR. Cumulative response rates in T315I+ CP-CML pts (n=76) were: MCyR, 75%; CCyR, 72%; MMR, 61%, and MR4.5, 37%. In PACE, estimated 3-yr PFS/OS rates for 64 T315I+ CP-CML pts were 60%/78% (medians not reached). One yr post-landmark outcomes for T315I+ CP-CML pts by treatment status at the 2-yr landmark time point are displayed in the table. Most common treatment-emergent AEs (≥40%) in the pooled group of T315I+ CP-CML pts (n=76 phase 1 and PACE) were: rash, 55%; dry skin, 49%; headache, 46%; abdominal pain, 43%; nausea, 41%; and fatigue, 41%. Among these pts, the cumulative incidence of any AOE (grade 3/4) was 32% (20%); by subcategory: cardiovascular 20% (15%), cerebrovascular 12% (5%), and peripheral vascular 13% (8%) events. Two T315I+ CP-CML pts had grade 5 AOEs. The exposure-adjusted incidence rate of new AOEs in T315I+ CP-CML pts was 12/100 pt-yrs. Conclusions: Ponatinib continues to provide deep and durable responses with >3 yrs median follow-up in T315I+ CP-CML pts. Survival outcomes with ponatinib treatment in these highly refractory pts were high overall and compare favorably with those observed in T315I+ CP-CML pt populations prior to the availability of ponatinib. Although pt numbers are limited for the landmark analysis, continuation of ponatinib treatment at 2 yrs was associated with a trend for improved OS, where data continue to mature. Updated data in all T315I+ pts will be presented. Study sponsor: ARIAD Pharmaceuticals, Inc. Disclosures Jabbour: ARIAD: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Novartis: Research Funding; BMS: Consultancy. Cortes:ARIAD: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Teva: Research Funding. Talpaz:Incyte Corporation: Other: Travel expense reimbursement, Research Funding; Novartis: Research Funding; Ariad: Other: Expense reimbursement, travel accomodation expenses, Research Funding; Pfizer: Consultancy, Other: travel accomodation expenses, Research Funding. Baccarani:ARIAD: Consultancy, Honoraria, Other: travel, accommodations, expenses , Speakers Bureau; BMS: Honoraria, Speakers Bureau; Novartis: Honoraria, Other: travel, accommodations, expenses , Speakers Bureau; Pfizer: Honoraria, Speakers Bureau. Mauro:BMS: Consultancy, Honoraria; ARIAD: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria. Hochhaus:Pfizer: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; BMS: Honoraria, Research Funding; ARIAD: Honoraria, Research Funding. Hughes:Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Ariad: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Consultancy, Honoraria. Guilhot:ARIAD: Honoraria. Deininger:BMS: Consultancy, Research Funding; Gilead: Research Funding; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Incyte: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; CTI BioPharma Corp.: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding; Bristol Myers Squibb: Consultancy, Research Funding; Ariad: Consultancy, Membership on an entity's Board of Directors or advisory committees. Shah:ARIAD: Research Funding; Daiichi-Sankyo: Research Funding; BMS: Research Funding; Pfizer: Research Funding; Plexxikon: Research Funding. Flinn:Janssen: Research Funding; Gilead Sciences: Research Funding; Pharmacyclics LLC, an AbbVie Company: Research Funding; ARIAD: Research Funding; RainTree Oncology Services: Equity Ownership. Lustgarten:ARIAD: Employment, Equity Ownership. Rivera:ARIAD: Employment, Equity Ownership. Santillana:ARIAD: Employment, Equity Ownership. Kantarjian:Amgen: Research Funding; ARIAD: Research Funding; Bristol-Myers Squibb: Research Funding; Pfizer Inc: Research Funding; Delta-Fly Pharma: Research Funding; Novartis: Research Funding.

Background: Ponatinib is a potent oral tyrosine kinase inhibitor (TKI) active against native and mutant forms of BCR-ABL. It is approved for patients with resistant or intolerant CML or Ph+ ALL, or with the T315I mutation, which renders other TKIs ineffective. The USPI recommends a starting dose of 45 mg/day, with consideration of lower starting doses in patients with selected comorbidities. In the US, ponatinib is available exclusively through a specialty pharmacy that maintains prescribing data for all US ponatinib-treated patients. Analyses of dispensed ponatinib prescriptions for CP-CML patients show that median therapy duration exceeds 1.5 years but is variable across groups; examination of demographic, clinical and physician characteristics may reveal predictors of therapy duration. Methods: We performed a retrospective analysis of patients starting treatment with ponatinib over the 2.5-year period from 01 January 2014 and 30 June 2016 using data from referring physicians, patient intake forms and pharmacy dispensing records. Gender (M/F), age ( Results: 475 US patients identified with CP-CML initiated treatment with ponatinib over this 2.5-year period; K-M median time on therapy was 20.7 months. About one-half of patients were male (Table) and most were aged Conclusions: Real-world US data for CP-CML patients receiving ponatinib show that a number of subgroups have median duration on ponatinib exceeding 2 years, but suggest drivers of therapy duration may be complex including both disease (e.g. T315I, prior line of tx) and patient (e.g. sex) related factors. Study sponsor: ARIAD Pharmaceuticals, Inc. Disclosures Mauro: Novartis: Consultancy, Honoraria, Research Funding; BMS: Consultancy, Honoraria; ARIAD: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria. McGarry:ARIAD: Employment, Equity Ownership. Lustgarten:ARIAD: Employment, Equity Ownership. Huang:ARIAD: Employment, Equity Ownership.