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PURPOSE Insertion mutations in Erb-b2 receptor tyrosine kinase 2 gene ( ERBB2 or HER2) exon 20 occur in 2%-5% of non–small-cell lung cancers (NSCLCs) and function as an oncogenic driver. Poziotinib, a tyrosine kinase inhibitor, was evaluated in previously treated patients with NSCLC with HER2 exon 20 insertions. METHODS ZENITH20, a multicenter, multicohort, open-label phase II study, evaluated poziotinib in patients with advanced or metastatic NSCLC. In cohort 2, patients received poziotinib (16 mg) once daily. The primary end point was objective response rate evaluated by independent review committee (RECIST v1.1); secondary outcome measures were disease control rate, duration of response, progression-free survival, and safety and tolerability. Quality of life was assessed. RESULTS Between October 2017 and March 2021, 90 patients with a median of two prior lines of therapy (range, 1-6) were treated. With a median follow-up of 9.0 months, objective response rate was 27.8% (95% CI, 18.9 to 38.2); 25 of 90 patients achieved a partial response. Disease control rate was 70.0% (95% CI, 59.4 to 79.2). Most patients (74%) had tumor reduction (median reduction 22%). Median progression-free survival was 5.5 months (95% CI, 3.9 to 5.8); median duration of response was 5.1 months (95% CI, 4.2 to 5.5). Clinical benefit was seen regardless of lines and types of prior therapy, presence of central nervous system metastasis, and types of HER2 mutations. Grade 3 or higher treatment-related adverse events included rash (48.9%), diarrhea (25.6%), and stomatitis (24.4%). Most patients had poziotinib dose reductions (76.7%), with median relative dose intensity of 71.5%. Permanent treatment discontinuation because of treatment-related adverse events occurred in 13.3% of patients. CONCLUSION Poziotinib demonstrates antitumor activity in previously treated patients with HER2 exon 20 insertion NSCLC.

Introduction: ERBB2 or HER2 alterations are found in approximately 2% to 5% of NSCLCs; most are exon 20 insertion mutations. The efficacy and safety of poziotinib, an oral tyrosine kinase inhibitor, were assessed in patients with treatment-naive NSCLC whose tumors harbor HER2 exon 20 insertions. Methods: ZENITH20 is an open-label, multicohort, multicenter, global, phase 2 trial. ZENITH20-C4 enrolled treatment-naive patients with NSCLC with tumors harboring HER2 exon 20 insertions. Poziotinib was administered 16 mg once daily (QD) or 8 mg twice daily (BID). The primary end point was objective response rate (ORR) by independent central review. Secondary and exploratory end points included disease control rate, duration of response, progression-free survival, and safety. Results: A total of 80 patients (16 mg QD, n = 47; 8 mg BID, n = 33) were treated in ZENITH20-C4. ORR was 39% (95% confidence interval [CI]: 28%–50%; 31 of 80), with a disease control rate of 73% (95% CI: 61%–82%; 58 of 80); 80% of the patients experienced tumor reduction. Median duration of response was 5.7 (95% CI: 4.6–11.9) months, and median progression-free survival was 5.6 (95% CI: 5.4–7.3) months. The most common grade 3 treatment-related adverse events were rash (QD, 45%; BID, 39%), stomatitis (QD, 21%; BID, 15%), and diarrhea (QD, 15%; BID, 21%). Among all subtypes of HER2 exon 20 insertions, seven patients (9%) harboring tumors with G778_P780dupGSP had the best clinical outcomes (ORR, 71%). Conclusions: Poziotinib was found to have clinically meaningful efficacy with a manageable toxicity profile for patients with treatment-naive NSCLC harboring HER2 exon 20 mutations.

Background: Eflapegrastim (Rolontis®, Efla) represents the first novel, long-acting granulocyte-colony stimulating factor (G-CSF) to be introduced in more than 15 years. Efla consists of a recombinant human G-CSF analog conjugated to a human IgG4 Fc fragment via a polyethylene glycol linker. Preclinical, clinical, and pharmacodynamic/pharmacokinetic data have shown increased potency for Efla versus pegfilgrastim (Peg). Both independent, randomized Phase 3 studies comparing Efla and Peg for prophylaxis of chemotherapy-induced neutropenia in patients with early-stage breast cancer (ESBC) met the primary endpoint of non-inferiority in duration of severe neutropenia (SN; ANC75kg. The safety profiles, including AEs and discontinuations, for Efla and Peg were comparable, and >99% of all patients received full dose of TC on schedule. The majority (67%) of patients with SN experienced a 1 day duration, occurring between Days 7 and 8 after TC. Mean duration of SN for Efla was statistically lower than for Peg (0.24 vs. 0.36 days; p=0.029). The above statistical significance was maintained for Efla after adjusting for demographic and baseline characteristics, namely age, weight, enrolling geographical region, and treatment setting in a multivariate model. Similarly, the incidence of SN for Efla was statistically lower than Peg in Cycle 1 (17.5% vs 24%; relative risk reduction [RRR]=27%; p=0.043). Univariate analysis of the incidence of SN showed a significant risk reduction in favor of Efla (8.6% vs 14.1%; p=0.034) for patients weighing >75kg (p=0.034). Multivariate analysis of SN showed significant odds ratio of SN for age ≥65 years and baseline ANC >6 × 109/L in favor of Efla (OR=0.42 and 0.39, respectively). The incidence of SN in Cycles 2-4 was comparable between treatment groups. Also, the incidence of febrile neutropenia and neutropenic complications was similar with 75kg. Eflapegrastim is a novel, long-acting and potent recombinant human G-CSF which may provide an attractive option in supporting patients at risk for SN-related complications. Citation Format: Lee S Schwartzberg, Gajanan Bhat, Alvaro Restrepo, Osama Hlalah, Inderjit Mehmi, Yong Wha Moon, Seungjae Baek, Shanta Chawla, Francois Lebel, Patrick Wayne Cobb. Pooled efficacy analysis from two phase 3 studies in patients receiving eflapegrastim, a novel, long-acting granulocyte-colony stimulating factor, following TC for early-stage breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS9-59.

Background: Poziotinib is a novel pan-HER inhibitor that irreversibly blocks the EGFR family of tyrosine-kinase receptors and inhibits the proliferation of tumor cells. This study evaluates the safety and clinical activity of poziotinib in patients with HER2-positive metastatic breast cancer (MBC) who received at least 2 therapies (trastuzumab and TDM-1) in dose-schedule ranging study. Methods: Patients were treated with oral poziotinib in 2 dose cohorts: 24mg daily 2 weeks/1 week off and 16mg daily continuously in a 21-day cycle. Dose reduction was allowed if toxicity observed. Patients continued treatment until disease progression, death, intolerable AE, or for a maximum of 24 months. The primary endpoint was the objective response rate (ORR), evaluated using RECIST 1.1. Secondary endpoints included disease control rate (DCR), duration of response (DOR), progression-free survival (PFS) and safety. Results: Sixty-seven patients (33 in 24mg; 34 in 16mg) were enrolled (57 evaluable) in 2 cohorts; all patients either completed or discontinued (36 PD, 5 deaths due to PD, 16 AEs) the study with 1 completed 25 months of treatment. The median (range) age was 57 (29-94) years. Patients were heavily pretreated and the median (range) lines of previous therapy were 7 (2-13) and 4 (2-16) in 2 cohorts respectively [unique drugs 3 (2-5) and 3 (1-9)]; 75% received pertuzumab in addition to trastuzumab and TDM-1 and 37% received at least one tyrosine kinase inhibitor (TKI). The mean relative dose intensity was 57% and 51% with 67% and 47% had dose reductions in 2 cohorts respectively. Common Grade ≥3 treatment-related AEs were similar to other 2nd generation TKIs and include diarrhea (30%), rash (28%) and stomatitis (7%). The ORRs were 27% and 26% with the corresponding median DORs of 5.6 and 13 months respectively. 3 patients in 16mg dose had a CR and another 2 patients had an unconfirmed CR. The DCRs were 50% and 70% in 2 cohorts along with median PFS of 4.1 and 5.8 months respectively. The ORRs were 25% each in 2 cohorts in 24 and 20 heavily pre-treated patients with ≥4 lines of therapy that included trastuzumab, TDM1 and pertuzumab. The ORRs were 23% and 0% in 2 cohorts with 13 and 10 patients received at least one tyrosine kinase inhibitor (TKI) as the sample sizes were small to make any meaningful evaluation. Conclusion: Poziotinib has demonstrated clinical activity in this dose-ranging study with tumor reduction shown in the majority of patients along with durable responses in this heavily pre-treated MBC patients. Safety profile was mechanism related and was similar to other 2nd generation TKIs. Citation Format: Adam Brufsky, Malik Zulfiqar, Julio Peguero, Kate Lathrop, Gajanan Bhat, Francois Lebel. A Phase 2 study of poziotinib in patients with HER2-positive metastatic breast cancer heavily pre-treated with HER2-targeted therapy [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD1-07.

Eflapegrastim (Rolontis) is a long-acting granulocyte colony-stimulating factor (G-CSF) with an IgG4 Fc fragment and short polyethylene glycol linker. Current G-CSF products are administered 24 hours after chemotherapy. The present study compares the duration of neutropenia (DN) with eflapegrastim or pegfilgrastim at 0, 2, 5, or 24 hours post chemotherapy. Eflapegrastim was evaluated by G-CSF receptor binding and bone marrow cell proliferation assays in vitro. Eflapegrastim-Fc component binding to Fcγ receptors C1q and FcRn was assessed by enzyme-linked immunosorbent assay. Neutropenia was induced in rats via intraperitoneal cyclophosphamide or docetaxel/cyclophosphamide. Rats received chemotherapy followed by vehicle, pegfilgrastim, or eflapegrastim at 2, 5, or 24 hours. The difference in DN after treatment was assessed. In vitro binding to G-CSF receptor of both agents was similar. Binding to FcRn and no binding to Fcγ receptors or C1q were observed with eflapegrastim. Studies in chemotherapy-induced neutropenic rats revealed shorter DN with eflapegrastim versus pegfilgrastim. Increased levels of G-CSF in serum and marrow were observed in groups treated with eflapegrastim versus those treated with pegfilgrastim. Although eflapegrastim and pegfilgrastim have similar in vitro binding affinity, the Fc fragment in eflapegrastim increases the uptake into bone marrow, resulting in increased therapeutic potential for chemotherapy-induced neutropenia. Eflapegrastim's greater marrow resident time provided a pharmacodynamic advantage over pegfilgrastim, translating into shortened duration of neutropenia. Our findings support eflapegrastim same-day administration with chemotherapy, warranting further evaluation in patients undergoing myelosuppressive chemotherapy.

Eflapegrastim (Rolontis) is a long-acting granulocyte colony-stimulating factor (G-CSF) produced by conjugating a human G-CSF analogue and a human immunoglobulin G4 Fc fragment, linked via a polyethylene glycol linker. Weight-based doses of 45 to 270 μg/kg eflapegrastim (12.3-73.6 μg/kg as G-CSF) were evaluated in a phase 2 study in patients. Based on these results, a fixed dose of 13.2 mg eflapegrastim (3.6 mg G-CSF) was compared with pegfilgrastim (6 mg G-CSF) in 2 phase 3 studies and in a pharmacokinetic single-arm multicenter study. Absolute neutrophil count (ANC) data from these 3 studies were evaluated in patients with early-stage breast cancer who were treated with docetaxel and cyclophosphamide (n = 669). Serum concentrations of eflapegrastim were determined by enzyme-linked immunosorbent assay. Eflapegrastim systemic exposures were higher in cycle 1 than in cycle 3, likely attributable to the higher ANC in cycle 3, increasing neutrophil-mediated clearance. Eflapegrastim elicited a greater effect on ANC than pegfilgrastim in patients at ∼60% of the G-CSF dose. Body weight had no clinically significant effect on response, justifying administration of a fixed dose of eflapegrastim. The results from 2 phase 3 studies demonstrate that eflapegrastim at a fixed dose of 13.2 mg (3.6 mg G-CSF) administered once per chemotherapy cycle is effective in prophylactic treatment of chemotherapy-induced neutropenia.

Background: Eflapegrastim (E) represents the first myeloid growth factor innovation in more than 15 years. A novel, long-acting recombinant human granulocyte-colony stimulating factor (rhG-CSF), E consists of a rhG-CSF analog conjugated to a human IgG4 Fc fragment via a polyethylene glycol linker. Preclinical and Phase I and II pharmacodynamic and pharmacokinetic data showed increased potency for E versus pegfilgrastim (P). Two independent randomized Phase III trials comparing fixed dose E and P (E 3.6 mg G-CSF and P 6.0 mg G-CSF) for the management of chemotherapy-induced neutropenia (CIN) have recently been completed. Both trials met the primary endpoint of non-inferiority for E vs P in Cycle 1 duration of severe neutropenia (P Patients and Methods: Patients with early-stage breast cancer (ESBC) who were candidates for adjuvant or neoadjuvant chemotherapy were randomized 1:1 in two open-label Phase III trials to E 13.2 mg (3.6 mg G-CSF) or standard P (6 mg G-CSF) administered on Day 2 following TC (docetaxel/cyclophosphamide) chemotherapy on Day 1 of each of 4 cycles. Blood for CBC and serum chemistry was collected in every cycle. Safety assessments began with the first dose of TC and continued for one year after the last dose of study drug. AEs and laboratory values were graded according to NCI CTCAE version 4.03. Immunogenicity was assessed from blood samples collected on Day 1 of each cycle, at the end-of-treatment visit, and at 6- and 12-month follow-up visits. Results: A total of 660 patients who received at least one dose of eflapegrastim (n=334) or pegfilgrastim (n=326) were included in this integrated safety analysis. The two treatment groups were well balanced for demographics and baseline disease characteristics. The mean age was 59y, ~40% were aged >65y, ~54% weighed >75kg, and ~80% were treated in the adjuvant setting. Median relative dose intensity for T and C was >99% for both groups. A similar percentage of patients in both treatment groups discontinued treatment due to AEs (4% E vs 6% P), with 2% in each group discontinuing due to AEs related to E or P. Serious AEs were similar in both groups (15% each). Incidence of AEs irrespective of causality were also similar between groups (74% E vs. 72% P). No notable differences between groups were observed in the types of study-drug-related AEs. The majority of study-drug-related AEs occurred with an incidence ≤10% for both E and P. As expected with myeloid growth factors, study-drug-related AEs occurring in >10% in either group were bone pain (E vs P: 33% vs 34%), arthralgia (15% vs 10%), back pain (14% vs 9%), myalgia (14% vs 9%), and headache (11% vs 8%). Incidence of febrile neutropenia and neutropenic complications were similar and less than 5% in each treatment group. No leukocytosis, splenic rupture, or anaphylaxis was reported in any patient receiving E or P. The overall incidence of immunogenicity was similar in both groups and there was no demonstrable impact on clinical safety or efficacy. Conclusions: Two large, randomized Phase III trials (Total n=660) of E vs P administered once-per-cycle showed E at a lower G-CSF dose to be safe and effective for the prophylaxis of CIN in patients with ESBC receiving TC chemotherapy. E is a novel long-acting rhG-CSF with increased potency and similar toxicity to P and may provide an attractive alternative for growth factor support of patients at high risk for CIN-related complications. Citation Format: Lee S Schwartzberg, Gajanan Bhat, Julio Peguero, Richy Agajanian, Jayaram Bharadwaj, Alvaro Restrepo, Osama Hlalah, Inderjit Mehmi, Shanta Chawla, Francois Lebel, Patrick W Cobb. Eflapegrastim, a novel long-acting granulocyte-colony stimulating factor: Integrated safety results in patients with early-stage breast cancer treated with TC chemotherapy [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-14-12.

Glioblastoma (GBM) is inherently immunosuppressed (cold). Short term localized controlled immune activation has been shown to increase cytotoxic T cell infiltrate, resulting in reduced tumor growth and prolonged survival (Barrett et al. 2018). We have developed an encapsulated-mouse IL-12 formulation (mPCX12), using a sustained IL-12 release platform (Egilmez et al. 2000) to facilitate short term localized immune activation in the tumor without systemic toxicity. mPCX12 elicited a sustained dose-related IL-12 release concomitant with downstream IFNγ in mouse splenocytes, demonstrating mPCX12’s biologic activity. Similar results were observed with hPCX12 in human PBMCs. In an orthotopic murine glioma model, C57B6/L mice were inoculated with 3 × 105 GL-261 glioma cells in the frontal lobe via intracranial injection with drug treatment on Day 5. Mice were randomly assigned (n=22/group) to receive a single intratumoral dose of mPCX12 at 0.5, 0.75 and 1 mg, or mrIL-12 1µg (equivalent to mPCX12 1mg), or empty shells or vehicle. In addition, lomustine (6 mg/kg, QD×5 i.p.) was also assessed. The results showed that mPCX12 treatment increased tumor IL-12 and downstream IFNγ levels in a dose dependent manner. At 1mg mPCX12, tumor IL-12 and IFNγ levels were 2069±631 and 646±8 pg/mg, respectively, on Day 3. Low levels of IL-12 and IFNγ were observed in the systemic circulation of mPCX12 and mrIL-12 groups. mPCX12 tumor IL-12 level persisted, while mrIL-12 returned to baseline by Day 7. Flowcytometric immunophenotyping of tumors showed increased cytotoxic T cells in mPCX12 treated gliomas. These increases in local cytokine levels translated into a dose-related prolongation of survival compared to the median survival in the groups treated with vehicle and empty shells (~19 days), lomustine (20 days), and mrIL-12 (37 days). mPCX12 elicited a dose-related increase in survival. For mPCX12 at 1mg, the median survival was >90 days. At Day 90, 41%, 45% and 55% of the animals that received doses of 0.5, 0.75 or 1mg mPCX12, respectively, were alive with median survival >90 days (last day of study). At the end of the study, a portion of the surviving mice subgroups were euthanized, and those animals treated with mPCX12 were tumor free. The remaining surviving mPCX12-treated animals from the 0.75 mg and 1 mg mPCX12 groups were reinoculated with 3 × 105 GL261 cells in the ipsilateral side of the brain and compared with age-matched control vehicle or empty shells. The median survival in control groups was 27 days, and all rechallenged mPCX12-treated groups survived at Day 90, demonstrating memory T cell activation. In summary, short-term controlled release of locally administered IL-12 via PCX12 resulted in turning cold tumors hot, resulting in enhanced overall survival in an orthotopic GBM model. Thus, short term controlled locally administered PCX12 warrants further investigation in GBM patients. Citation Format: Sribalaji Lakshmikanthan, Damaris Diaz, Prasad Kolli, Arunthi Thiagalingam, Paul M. Gonzales, Mario Sepulveda, Jessica Dalsing-Hernandez, Francois Lebel, John A. Barrett. Intratumorally administrated encapsulated IL-12 (PCX12) promotes anti-tumor immune response in GL-261 murine orthotopic glioma model [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 2086.

Introduction: Detection of ctDNA in plasma samples permits temporal assessment of tumor mutation status during treatment. Poziotinib is an oral pan-HER TKI that has been demonstrated to be efficacious in NSCLC patients harboring HER2 exon 20 insertion mutations. We assessed serial plasma samples for changes in tumor genotype in both treatment naive and second line patients to evaluate correlation with clinical response. Methods: For NSCLC patients, HER2 exon 20 insertion mutations identified by tumor tissue based NGS were required for entry into the ZENITH20 study. Plasma samples were collected prior to treatment and at C3D1 (8 weeks post treatment 16mg poziotinib QD). The Guardant360® 74-gene liquid biopsy assay, which assessed changes in ctDNA and, subsequently, mean variant allele fraction (mVAF), was utilized for analysis of samples. The Guardant360 Response™ Molecular Response (MR) algorithm was calculated as a ratio of mVAF of oncogenic alterations at baseline compared to poziotinib treatment at C3D1. Results: 23 patients with tumor tissue confirmed NSCLC harboring HER2 exon 20 insertion mutations were studied. 22 of 23 (96%) had baseline plasma samples with detectable ctDNA. 21 of 22 samples had detectable HER2 exon 20 insertion mutations, resulting in a concordance of 95% versus tissue based NGS. The most prevalent HER2 exon 20 insertion alteration was the A775_G776ins YVMA variant, found in 50% of the baseline blood and tumor samples using both methods (100% concordance). 16 of 17 patients had both baseline and C3D1 samples, permitting assessment of temporal response. 15 of the 16 (94%) patients demonstrated a decrease in mVAF at C3D1 compared to the mVAF at baseline. 12 of 15 patients demonstrated an >50% reduction in mVAF at C3D1, with 7 of the 12 patients showing >95% reduction in mVAF at C3D1 with clinical outcomes of 5 PRs, 1 non-CR/non-PD and 1 SD. Interestingly, 3 of these patients showed complete clearance of ctDNA target HER2 exon 20 insertions at the C3D1 timepoint. Conclusions: Baseline plasma ctDNA genotyping correlated with tumor tissue based NGS in an NSCLC patient population with HER2 mutations. Poziotinib treatment resulted in mVAF reduction, which correlated with clinical response per RECIST1.1. Assessment of longitudinal changes in ctDNA during drug therapy may potentially be used to predict patient response and possibly tumor resistance. Further evaluation in larger cohorts and longer duration of treatment is required to help elucidate the impact of these findings. Citation Format: Arunthi Thiagalingam, Sribalaji Lakshmikanthan, Allysia J. Mak, Scott A. Shell, Sharon Leu, Rocky Washington, Lyndah Dreiling, Gajanan Bhat, Francois Lebel, John A. Barrett. Predictive ability of circulating tumor DNA by Guardant360 in poziotinib-treated patients with NSCLC harboring HER2 exon 20 insertion mutations [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 3400.

Background: Chemotherapy-induced neutropenia increases the likelihood of life-threatening infections. Currently, long-acting G-CSF products are administered 24 hours after chemotherapy (CT). Eflapegrastim's (Efla) greater marrow resident time should provide a pharmacodynamic advantage over pegfilgrastim (Peg), translating into a shorter duration of neutropenia (DN). The therapeutic potential of Efla, a long-acting G-CSF, was evaluated in a neutropenic rat model where neutropenia was induced via intraperitoneal docetaxel/cyclophosphamide. This study compared the DN with that of vehicle control and Peg at 0, 2, 5, and 24 hrs post-CT. We found that at all-time points, there was a marked reduction in the degree of neutropenia and a more rapid rate of absolute neutrophil count (ANC) recovery with Efla compared to Peg. When Efla was administered concomitantly with CT, ANC returned to normal within 12hrs for Efla vs 2.2 days post-nadir for Peg, while the DN in the vehicle group was 7 days. Pharmacokinetics (PK) of Efla for same-day dosing were similar to those reported for next-day dosing. Based on these results, a Phase 1 clinical trial is ongoing; results for the first 9 patients are reported. Material and Methods: Phase 1, open-label study where Efla is administered at a fixed dose of 13.2 mg at 0.5, 3, and 5 hours s.c. after the i.v. infusion of docetaxel (75 mg/m2) and cyclophosphamide (600 mg/m2) CT in patients with confirmed stage I-IIIA breast cancer. Patients >18 years, ECOG Citation Format: John A. Barrett, Shanta Chawla, Prasad S. Kolli, Yu- Yon Kim, Sri Lakshmikanthan, Meera Tugnait, Lyndah K. Dreiling, Francois Lebel. Same-day administration of Eflapegrastim with chemotherapy enhances neutropenic recovery in neutropenic rats and in early-stage breast cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT116.

Background: Eflapegrastim (Rolontis®, Efla) is a long-acting granulocyte-colony stimulating factor (G-CSF), consisting of a recombinant human G-CSF analog conjugated to a human IgG4 Fc fragment via a short polyethylene glycol linker. Efla is not a biosimilar and represents the first myeloid growth factor innovation in more than 15 years. In preclinical studies with chemotherapy-induced neutropenic rats, Efla showed ~3-fold higher exposure in serum and higher exposure in bone marrow at similar doses compared to pegfilgrastim (Peg). The duration of neutropenia (DN) was shown to be significantly shorter with Efla vs Peg when administered on the same day or 24-hours post-chemotherapy. Additionally, the DN after Efla administered on the same day as chemotherapy was similar to the DN 24 hours post-chemotherapy. Moreover, in two Phase 3 studies that randomized a total of 643 patients with early-stage breast cancer (ESBC) to either Efla (3.6 mg G-CSF n=314) or Peg (6 mg G-CSF n=329) given ~ 24 hours after docetaxel and cyclophosphamide (TC), the duration of severe neutropenia (DSN) was statistically noninferior in patients treated with Efla compared to Peg. As a standard of practice, G-CSF products require administration 24 hours after chemotherapy. Since Efla preclinical and clinical results suggest that the increased activity of Efla may provide effective prophylaxis against chemotherapy-induced neutropenia when administered on the same day as chemotherapy, the purpose of this study is to assess the feasibility of giving Efla same-day (at 3 different dosing timepoints) in patients receiving TC for the treatment of ESBC. Study Design and Methods : This is a randomized, schedule finding, multicenter, Phase 1, open-label study evaluating the same-day administration of 13.2 mg/0.6 mL Efla following IV infusion of docetaxel (75 mg/m2) and cyclophosphamide (600 mg/m2) in patients with ESBC. Treatment: On Cycle 1, Day 1, patients will be randomized 1:1:1 to Efla dose administration schedules of 0.5, 3, and 5 hours after TC. In Cycles 2-4, Efla will be administered ~ 24 hours following the administration of TC for all treatment arms. Clinical Endpoints: The primary endpoint is DSN (ANC Inclusion Criteria: This study is enrolling histologically confirmed (operable stage I-IIIA) patients with ESBC, who are >18 years of age, are candidates for neoadjuvant or adjuvant TC, have an ECOG of Exclusion Criteria: Patients will be excluded if they have an active or concurrent malignancy, or locally recurrent/metastatic or bilateral breast cancer, a life-threatening disease, a known sensitivity or previous reaction to E. coli derived products, exposure to a G-CSF agent within 3 months, history of bone marrow or hematopoietic stem cell transplant, radiotherapy or surgery within 30 days, are pregnant or are breast-feeding. Statistical Methods: A sample size of 15 patients per dosing schedule arm was determined to provide adequate precision for the 95% CI of the DSN and secondary endpoints, including PK parameters, assuming a standard deviation of 1.0 days based on the prior studies. A safety evaluation will be performed once the first three patients in each arm have completed Cycle 1. Target Accrual: 45 patients (15 subjects/arm). Enrollment began in April 2020. Disclosures Schwartzberg: Spectrum Pharmaceuticals, Inc.: Consultancy, Other: clinical investigator for trial. Francis:Spectrum Pharmaceuticals, Inc.: Other: clinical investigator for trial. Osama:Spectrum Pharmaceuticals, Inc.: Other: clinical investigator for trial. Modiano:Spectrum Pharmaceuticals, Inc.: Other: clinical investigator for trial. Bharadwaj:Spectrum Pharmaceuticals, Inc.: Other: clinical investigator for trial. Chawla:Spectrum Pharmaceuticals, Inc.: Current Employment, Current equity holder in publicly-traded company. Bhat:Spectrum Pharmaceuticals, Inc.: Current Employment, Current equity holder in publicly-traded company. Lebel:Spectrum Pharmaceuticals, Inc.: Current Employment, Current equity holder in publicly-traded company. Tchekmedyian:Spectrum Pharmaceuticals, Inc.: Other: clinical investigator for trial.

Human interleukin-12 (hIL-12) is a cytokine with anticancer activity, but its systemic application is limited by toxic inflammatory responses. We assessed the safety and biological effects of an hIL-12 gene, transcriptionally regulated by an oral activator. A multicenter phase 1 dose-escalation trial (NCT02026271) treated 31 patients undergoing resection of recurrent high-grade glioma. Resection cavity walls were injected (day 0) with a fixed dose of the hIL-12 vector (Ad-RTS-hIL-12). The oral activator for hIL-12, veledimex (VDX), was administered preoperatively (assaying blood-brain barrier penetration) and postoperatively (measuring hIL-12 transcriptional regulation). Cohorts received 10 to 40 mg of VDX before and after Ad-RTS-hIL-12. Dose-related increases in VDX, IL-12, and interferon-γ (IFN-γ) were observed in peripheral blood, with about 40% VDX tumor penetration. Frequency and severity of adverse events, including cytokine release syndrome, correlated with VDX dose, reversing promptly upon discontinuation. VDX (20 mg) had superior drug compliance and 12.7 months median overall survival (mOS) at mean follow-up of 13.1 months. Concurrent corticosteroids negatively affected survival: In patients cumulatively receiving >20 mg versus ≤20 mg of dexamethasone (days 0 to 14), mOS was 6.4 and 16.7 months, respectively, in all patients and 6.4 and 17.8 months, respectively, in the 20-mg VDX cohort. Re-resection in five of five patients with suspected recurrence after Ad-RTS-hIL-12 revealed mostly pseudoprogression with increased tumor-infiltrating lymphocytes producing IFN-γ and programmed cell death protein 1 (PD-1). These inflammatory infiltrates support an immunological antitumor effect of hIL-12. This phase 1 trial showed acceptable tolerability of regulated hIL-12 with encouraging preliminary results.

9093 Background: Treatment addressing non-small cell lung cancer (NSCLC) harboring EGFR or HER2 exon 20 insertion mutations remains an unmet need. These tumors are associated with a high incidence of CNS metastases and unfavorable survival rates. Poziotinib is a potent, irreversible, tyrosine kinase inhibitor (TKI) with a structure that can overcome the steric hindrance of the exon 20 limited binding pocket. Preclinical data suggest poziotinib CNS penetration, and here we show meaningful poziotinib CNS activity in patients with NSCLC harboring exon 20 insertion mutations in an ongoing multi-cohort, multi-center Phase 2 study (ZENITH20; NCT03318939). Methods: ZENITH20 enrolled previously treated and naïve patients with advanced/metastatic NSCLC and EGFR or HER2 exon 20 insertion mutations in several cohorts: Cohort 1 (C1) EGFR previously treated; Cohort 2 (C2) HER2 previously treated and Cohort 3 (C3) EGFR treatment-naïve. All patients with stable CNS metastases at baseline were included. Poziotinib (16 mg) was administered orally QD, with follow-up for up to 24 months. The primary endpoint was Objective Response Rate (ORR) evaluated centrally using RECIST v1.1 by an independent image review committee. Secondary endpoints included Disease Control Rate (DCR), Duration of Response (DOR), Progression-Free Survival (PFS) and safety. Primary efficacy results have been previously released. Intracranial response was determined based on the modified RECIST criteria. Results: A total of 284 patients across 3 cohorts (C1 n=115; and C2 n=90; and C3 n=79) with a median age of 60.5 years were enrolled. The median follow-up was 7.3, 8.3, and 9.2 months for all patients in C1, C2, and C3, respectively. In NSCLC patients that had baseline CNS lesions (N=36), the analysis showed a patient-based ORR of 22.2% (8/36) and a DCR of 88.9% (32/36). One patient in each cohort had a complete intracranial response and stable disease was 80.6% across 3 cohorts and 92.9% in C2. Two patients each in C1 and C3 had progressive disease (PD) and none had CNS progression in C2 (Table). Conclusions: Poziotinib exhibited clinically meaningful CNS activity in patients with EGFR or HER2 exon 20 mutations in ZENITH20 Cohorts 1-3. The majority of the patients had no CNS progression and 3/36 patients had intracranial complete responses. The preliminary data suggest that poziotinib may provide a meaningful treatment alternative for patients with NSCLC that harbor EGFR or HER2 exon 20 mutations and who present with CNS metastases that have poor prognosis. Clinical trial information: NCT03318939. [Table: see text]

Background: Eflapegrastim (Rolontis®, Efla) is a long-acting granulocyte-colony stimulating factor (G-CSF), consisting of a recombinant human G-CSF analog conjugated to a human IgG4 Fc fragment via a short polyethylene glycol linker. Efla is not a biosimilar and represents the first myeloid growth factor innovation in more than 15 years. In preclinical studies with chemotherapy-induced neutropenic rats, Efla showed ~3-fold higher exposure in serum and higher exposure in bone marrow at similar doses compared to pegfilgrastim (Peg). The duration of neutropenia (DN) was shown to be significantly shorter with Efla vs Peg when administered on the same day and 24-hours post-chemotherapy. Additionally, the DN after Efla administered on the same day as chemotherapy was similar to the DN 24 hours post-chemotherapy. Moreover, in two Phase 3 studies that randomized a total of 643 patients with early-stage breast cancer (ESBC) to either Efla (3.6 mg G-CSF n=314) or Peg (6 mg G-CSF n=329) given ~ 24 hours after docetaxel and cyclophosphamide (TC) administration, the duration of severe neutropenia (DSN) was statistically noninferior in patients treated with Efla compared to Peg. As a standard of practice, G-CSF products require administration 24 hours after chemotherapy. Since Efla preclinical and clinical results suggest that the increased activity of Efla may provide effective prophylaxis against chemotherapy-induced neutropenia when administered on the same day as chemotherapy, the purpose of this study is to assess the feasibility of Efla same-day (3 different dosing timepoints) in patients receiving TC for treatment of ESBC. Trial Design: This is a randomized, schedule finding, multicenter, Phase 1, open-label study evaluating the same-day administration of 13.2 mg/0.6 mL Efla (3.6 mg G-CSF) following IV infusion of docetaxel (75 mg/m2) and cyclophosphamide (600 mg/m2) in patients with ESBC. Patients will be randomized 1:1:1 to Efla dose schedules of 0.5, 3, and 5 hours after TC. The primary endpoint is DSN (ANC 18 years of age, are candidates for neoadjuvant or adjuvant TC chemotherapy, have an ECOG of Citation Format: Lee S. Schwartzberg, Jawad Francis, Hlalah Osama, Manuel Modiano, Jayaram Bharadwaj, Shanta Chawla, Gajanan Bhat, Francois Lebel, Nishan Tchekmedyian. Open-label, phase 1 study to evaluate duration of severe neutropenia after same-day dosing of eflapegrastim in patients with breast cancer receiving docetaxel and cyclophosphamide (NCT04187898) [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr OT-06-01.

Major obstacles to developing effective immunotherapy are the ability of tumors to escape the immune system and the toxicity associated with systemic administration. To overcome these challenges, a gene delivery platform technology, RheoSwitch Therapeutic System (RTS), has been developed to enable the regulated expression of a target gene, Ad-RTS-IL-12, administered intratumorally, where IL-12 expression is controlled via the administration of an oral activator ligand, veledimex. Pharmacokinetics in healthy human subjects indicated that veledimex plasma exposure increased with increasing dose after single- and multiple-dose administration in Labrasol slurry and F-22 capsule formulations. No apparent formulation or sex-related difference in veledimex pharmacokinetics (PK) was observed. Minimal or no plasma accumulation of veledimex was observed after once-daily oral administration for 14 days. Veledimex steady state in plasma was reached after 5 daily doses. Food consumption prior to veledimex administration prolonged and enhanced absorption with no impact on the elimination rate and extent of metabolism of veledimex, resulting in significantly increased systemic exposure to veledimex and its 2 major circulating metabolites. Overall, veledimex was well tolerated and exhibited a PK profile supportive of once-daily dosing. For enhanced efficacy, veledimex should be taken under fed conditions to ensure optimal absorption and sufficient systemic exposure.

Introduction and Purpose of Study: Effective and approved therapy for treating non-small cell lung cancer (NSCLC) with EGFR exon 20 mutations is an unmet medical need. Poziotinib is a potent tyrosine kinase inhibitor (TKI) of EGFR and HER2 exon 20 insertion mutants. We evaluated the efficacy and safety of poziotinib in previously treated NSCLC patients with EGFR exon 20 insertion mutations (ZENITH20-1) in an independent cohort of a multi-cohort, multi-center Phase 2 study. Methods: Poziotinib (16 mg) was administered orally QD, allowing dose reductions for AEs, with follow up for 24 months. The primary endpoint was objective response rate (ORR), evaluated by central radiographic review using RECIST v1.1. The ORR endpoint was to be met if the lower bound of 95% CI>17% in the As-Treated Population. The secondary endpoints included disease control rate (DCR), duration of response (DOR), progression-free survival (PFS) and safety. Safety monitoring was conducted throughout the study. Results: A total of 115 patients with a median age of 61 years (33-83) were enrolled. Patients had received and failed prior therapy (median of 2 [1-9]) with majority receiving both chemo and immunotherapy. The median relative dose intensity was 72% (7-100%) with 65% having dose reductions. 10% of patients discontinued due to related AEs. The ORR was 14.8% (95% CI 8.9%-22.6%), and the DCR was 68.7% (95% CI 59.4%-77.0%). Seventeen patients had a confirmed partial response (PR), 5 patients had unconfirmed PR and 62 (53.9%) patients had stable disease (SD). Overall, 75 (65%) patients had tumor size reductions. The median DoR was 7.4 months (95% CI 3.7-9.7) and the median PFS was 4.2 months (95% CI 3.7-6.6). Safety profile was mechanism related and similar to other 2nd generation tyrosine kinase inhibitors with the most common treatment-related Grade ≥3 AEs (preferred term) being rash (28%), diarrhea (26%), stomatitis (9%) and paronychia (6%). The incidence of treatment-related pneumonitis, an important AE associated with TKIs, was 4%. Conclusion: Although the ORR primary endpoint was not met, poziotinib induced tumor size reduction in the majority (65%) of patients. The tumor size reduction combined with long duration of response demonstrated the clinical activity of poziotinib in treating this patient population. We are further optimizing dosing and AE management. Citation Format: Xiuning Le, Jonathan Goldman, Jeffrey Clarke, Nishan Techekmedyian, Zofia Piotrowska, David Chu, Gajanan Bhat, Francois Lebel, Mark Socinski. Poziotinib activity and durability of responses in previously treated EGFR exon 20 NSCLC patients - a Phase 2 study [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT081.

Background: Eflapegrastim is a long-acting G-CSF that is comprised of a G-CSF analog and a recombinant IgG4 Fc fragment conjugated at their N-termini via a short polyethylene glycol linker. Currently, G-CSF products are administered 24 hours after chemotherapy. We compared the duration of neutropenia (DN) after treatment with eflapegrastim and pegfilgrastim given on the same-day, at three different timepoints, and after 24 hours in chemotherapy-induced neutropenic rats. Method: Neutropenia was induced in rats via intraperitoneal administration of cyclophosphamide and docetaxel (TC) chemotherapy. Rats (5 animals per group) were assigned to dose groups of either vehicle or equivalent doses (based on human clinical doses) of pegfilgrastim (103.3 µg/kg) or eflapegrastim (61.8 µg/kg as G-CSF) on the same day as chemotherapy at 0, 2, and 5 hours or 24 hours after chemotherapy. The primary endpoint was the difference in DN after TC treatment and administration of eflapegrastim or pegfilgrastim at the specified timepoints. Results: In the vehicle group, the TC regimen induced neutropenia in all animals with an ANC nadir occurring on approximately Day 4 and a mean DN of nearly 7 days. The mean DN values for treatment with eflapegrastim on the same day, at 0, 2, and 5 hours, and after 24 hours were similar and the mean DN values for eflapegrastim were significantly lower than for pegfilgrastim at all dosing timepoints (Table). Time after Chemotherapy(hours)Mean Duration of Neutropenia (days)Difference (95% CI)Eflapegrastim Time vs 24 hoursDifference (95% CI)EflapegrastimPegfilgrastim00.62.2-1.6 (-3.067, -0.133)0.4 (-0.08, 1.28)20.21.8-1.6 (-2.84, -0.36)0 (-0.19, 0.59)50.01.2-1.2 (-1.20, -1.20)-0.2 (0, 0)240.21.8-1.6 (-2.84, -0.36)NA Conclusions: The DN for same-day treatment with eflapegrastim at 0, 2, and 5 hours was similar to that of the treatment after 24-hours. However, the mean DN values were significantly lower for eflapegrastim than pegfilgrastim at all time points. Further exploration of the potential advantage of same-day dosing with eflapegrastim in patients undergoing chemotherapy is warranted. Citation Format: Yu-Yon Kim, Eunjung Kim, Hyesun Han, Seungjae Baek, Shanta Chawla, Prasad Kolli, Gajanan Bhat, Francois Lebel. Chemotherapy induced neutropenia in rats following administration of eflapegrastim or pegfilgrastim on the same day at three different timepoints and at 24 hours post-chemotherapy [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2044.

9514 Background: Treatment of non-small cell lung cancer (NSCLC) with EGFR exon 20 mutations is an unmet medical need. Poziotinib is a potent tyrosine kinase inhibitor (TKI) of EGFR and HER2 exon 20 insertion mutants. We evaluated the efficacy and safety of poziotinib in previously treated NSCLC patients with EGFR exon 20 insertion mutations in an independent cohort of a multi-cohort, multi-center Phase 2 study ( ZENITH20-1). Methods: ZENITH20-1 study enrolled pts with advanced NSCLC with an EGFR exon 20 insertion identified on local tissue testing who had received at least one prior line of therapy. Poziotinib (16 mg) was administered orally QD, allowing dose reductions for AEs, with follow up for 24 months. The primary endpoint was objective response rate (ORR), evaluated centrally by RECIST v1.1. Secondary endpoints included disease control rate (DCR), duration of response (DOR), progression-free survival (PFS) and safety. Efficacy was also evaluated by specific exon 20 insertions and prior lines of therapy. Results: 115 patients with a median age of 61 years (33-83) were enrolled. Patients had a median of 2 prior lines of therapy (range, 1-9.) The median relative dose intensity was 72% (7-100%) with 65% having dose reductions. The ORR in the as-treated population was 14.8% (95% CI 8.9 - 22.6%), and the DCR was 68.7% (95% CI 59.4 - 77.0%) with a median DoR of 7.4 months. 65% patients had tumor size reductions and the median PFS was 4.2 months. In the evaluable population (n = 88), the ORR was 19.3% and the unconfirmed ORR was 25%. Responses were predominantly observed in insertions between residues M766 to D770 of exon 20 (8/44; 18.2%). Responses were observed in patients with 2 lines (14%); ≥3 lines of therapy (16.2%). The most common treatment-related Grade ≥3 AEs were rash (28%), diarrhea (26%), stomatitis (9%) and paronychia (6%). The incidence of treatment-related pneumonitis was 4%, however some cases may have been confounded by prior checkpoint inhibitors as first line treatment. Conclusions: Although the ORR primary endpoint was not met, poziotinib induced tumor reduction in the majority of patients with durable responses, including the heavily pre-treated population. Responses were more common in patients with insertions between M766 to D770 of EGFR exon 20. The safety profile was overall consistent with other 2nd generation EGFR TKIs. Evaluation of these subgroups with refined dosing and improved toxicity management to maintain continuous treatment is warranted to assess the potential of poziotinib in Exon20 related tumors. Clinical trial information: NCT03318939 .

Ad-RTS-hIL-12 (Ad) is a novel gene therapy expressing IL-12 via the RheoSwitch Therapeutic System(®) gene switch under control of an oral activator ligand, veledimex (V). We previously reported on an open label Phase I trial describing biological activity of recombinant IL-12 with downstream IFN-γ and activation of the immune system. We provide an update on the intratumoral injections of Ad (2x10(11)virus-particles) + V for patients with recurrent GBM (rGBM) in Group 1 (G1) (craniotomy, n=31) and initial results for Group 2 (G2) (stereotactic administration n=7). In G1, the V 20-mg cohort mOS increased to 12.7 months with mean follow-up of 12.9 months. 20-mg V in G1 showed fewer toxicities and higher V compliance (84%) compared with higher-doses of V (30 and 40-mg) with 75% and 67%, respectively. These data are encouraging compared to historical data that predict mOS of 5 to 8 months. An additional cohort at V 10-mg (n=6) was well tolerated, but subtherapeutic, with a mOS of 7.6 months (mean follow-up 6.7 months). There was an association between V dose level, blood-brain-barrier penetration, and drug-related adverse events (AEs) with increased TEAEs observed above V 20-mg. Subgroup analyses across all cohorts did not detect statistically significant differences including extent of resection or IDH mutation status. Subjects (20-mg V) who received a cumulative dose of ≤10mg of dexamethasone during the first 15 days of treatment showed improved OS versus >100mg of dexamethasone, suggesting corticosteroid-mediated blunting of the IL-12 dependent immune-mediated therapeutic effect. In the G2 20-mg V cohort, similar cytokine levels and reversible AEs were observed compared to G1; follow up is ongoing and mOS will be presented. Based on these results and the best risk-benefit profile, the 20-mg V dose level was chosen for further investigation. Combination with an immune checkpoint inhibitor in rGBM is underway.

Modulating the tumor microenvironment with immuno-stimulatory therapy maybe an attractive approach for the treatment of glioma. We took advantage of IL-12 biology utilizing a replication-incompetent adenovirus (Ad) engineered to conditionally express mouse or human IL-12 (Ad-RTS-mIL-12 or Ad-RTS-hIL-12), via our RheoSwitch Therapeutic System® (RTS®) gene switch, tightly controlled by the oral activator ligand veledimex (V). Previous human and mouse studies demonstrated that V crosses the blood-brain-barrier (BBB), enabling controlled IL-12 expression. Ad-RTS-mIL-12 injected into orthotopic GL-261 glioma at the optimal dose of 5x109 viral particles (vp) +veledimex (Ad+V) elicited dose-related increases in local IL-12 and downstream IFN-gamma production. Cytokines within the tumor were ~20 times higher than serum and elicited sustained increases within glioma of cytotoxic T cells and macrophages concomitant with reduction in regulatory T cells (Tregs) resulting in enhanced survival where ~65% of mice receiving Ad+V 10-30mg/m2/day were tumor free 80 days after immunotherapy (end of study). Ad+V 10mg/m2/day was the optimal therapeutic index. Using allometric modeling, mouse Ad+V 10mg/m2/day translated into ~20mg V for a 70kg subject and supports Ad-RTS-hIL-12 up to 5x1012vp. Based on these results, a phase 1 trial in recurrent glioma studying local hIL-12 production using Ad-RTS-hIL-12 2x1011vp +V 10-40mg QDx14po. was initiated. Interim results demonstrated that V20mg elicited the optimal therapeutic index. Results at 20mg (N=15) demonstrated that V crossed the BBB with 35 ± 5% of plasma levels in tumor and peak serum levels of hIL-12 and IFN-gamma at 27 and 36pg/ml. Increase in circulating cytotoxic-T cell/Tregs ratio at days 14-28 correlated with an increase in the median overall survival of 12.5mo. Our working hypothesis tested in the mouse that IL-12 activates the immune response leading to mouse anti-tumor effects now appears to be validated in humans.

Successful immunotherapy is dependent on the regulation of an immune response concomitant with modulation of the tumor microenvironment. To study this hypothesis, we utilized a replication-incompetent adenovirus engineered to conditionally express mouse IL-12 (Ad-RTS-mIL-12), via our RheoSwitch Therapeutic System® (RTS®) gene switch which is tightly controlled by the oral activator ligand veledimex (V) in combination with the chemotherapeutic CCNU (lomustine, alkylating nitrosourea) in a GL-261 orthotopic glioma mouse model. The effects of Ad-RTS-mIL-12+veledimex (Ad+V) alone Ad 5x109vp+V 3-30mg/m2QDx14po or concomitantly with CCNU 9-18mg/m2QDx5ip were studied. Mice without treatment succumb to disease progression by day 39 (median 22 days). Ad+V 3mg/m2 monotherapy prolonged median overall survival (mOS) to 37 days. Eighty days after immunotherapy (end of study), ~65% mice receiving Ad +V 10-30mg/m2/day survived. CCNU 9mg/m2 failed to improve mOS while 18mg/m2 increased mOS to 36 days. Ad+V 3mg/m2 combined with CCNU 9mg/m2 failed to improve mOS while Ad+V 3mg/m2+CCNU 18mg/m2 increased survival with 60% surviving at study end. Ad+V 10mg/m2+CCNU 9mg/m2 failed to increase mOS over monotherapy while Ad+V 10mg/m2+CCNU 18mg/m2 resulted in 100% survival at end of study. Ad+V 30mg/m2+CCNU (9-18mg/m2) did not further improve survival with increased clinical signs over monotherapy that recovered on discontinuance of dosing. Ad+V increased tumor IL-12 (80 pg/mg) which was ~15-times greater than that of plasma while CCNU alone or in combination with Ad+V did not affect tumor and serum cytokines. Within the tumor, Ad+V elicited a dose-related increase in cytotoxic T cells and macrophages and decrease in regulatory T cells consistent with immune-mediated anti-tumor effects. Ad+V+CCNU did not further alter the tumor immune profile over Ad+V monotherapy. In summary, the controlled local immunostimulation with IL-12 combined with CCNU, warrants further investigation in GBM.

Glioblastoma (GBM) is an aggressive brain tumor affecting ~74,000 people worldwide annually. Recurrent GBM patients have a median overall survival (mOS) of 6–7 months. OS in patients who have failed temozolomide, bevacizumab or equivalent salvage chemotherapy, is ~3–5 months. New therapies are urgently needed. Ad-RTS-hIL-12 is a novel gene therapy expressing IL-12 under the control of an oral activator ligand, veledimex, via the RheoSwitch Therapeutic System® gene switch. Intratumoral administration of Ad-RTS-hIL-12 results in targeted tumor cytotoxicity and induction of systemic T cell memory. Ad-RTS-hIL-12 + veledimex is a treatment strategy to extend the IL-12 therapeutic window. In a multicenter, Phase I dose escalation trial and expansion cohort of subjects with recurrent or progressive Grade III or IV glioma undergoing resection, Ad-RTS-hIL-12 + veledimex was well tolerated; toxicities were predictable and reversible upon discontinuing veledimex with a correlation between veledimex dose, BBB penetration and drug related AEs to assigned dose level. The most common adverse reactions were related to cytokine exposure in the form of fever, decrease in peripheral lymphocytes and platelets, and elevation of liver transaminases. Emerging biomarker data appear to show that serum CD8+/FOXP3 ratio might represents a putative predictor of response. Subjects treated with 20mg of veledimex had a mOS of 12.5 months and when given ≤10mg of dexamethasone during the first 15 days of treatment, overall survival was improved, possibly suggesting a negative effect of steroids on immunostimulation. The tolerability and encouraging survival observed to date warrant additional clinical studies of this controlled immunogene therapy.

The purpose of this study was to determine if localized delivery of IL-12 encoded by a replication-incompetent adenoviral vector engineered to express IL-12 via a RheoSwitch Therapeutic System® (RTS®) gene switch (Ad-RTS-IL-12) administered intratumorally which is inducibly controlled by the oral activator veledimex is an effective approach for glioma therapy. Mice bearing 5–10-day-old intracranial GL-261 gliomas were intratumorally administered Ad-RTS-mIL-12 in which IL-12 protein expression is tightly controlled by the activator ligand, veledimex. Local tumor viral vector levels concomitant with veledimex levels, IL-12-mRNA expression, local and systemic cytokine expression, tumor and systemic flow cytometry and overall survival were studied. Ad-RTS-mIL-12+veledimex elicited a dose-related increase in tumor IL-12 mRNA and IL-12 protein and discontinuation of veledimex resulted in a return to baseline levels. These changes correlated with local immune and antitumor responses. Veledimex crossed the blood–brain barrier in both orthotopic GL-261 mice and cynomolgus monkeys. We have demonstrated that this therapy induced localized controlled production of IL-12 which correlates with an increase in tumor-infiltrating lymphocytes (TILs) leading to the desired biologic response of tumor growth inhibition and regression. At day 85 (study termination), 65% of the animals that received veledimex at 10 or 30 mg/m2/day were alive and tumor free. In contrast, the median survival for the other groups were: vehicle 23 days, bevacizumab 20 days, temozolomide 33 days and anti-PD-1 37 days. These findings suggest that the controlled intratumoral production of IL-12 induces local immune cell infiltration and improved survival in glioma, thereby demonstrating that this novel regulated immunotherapeutic approach may be an effective form of therapy for glioma.

Purpose To evaluate the efficacy of the addition of palifosfamide to carboplatin and etoposide in extensive stage (ES) small-cell lung cancer (SCLC). Patients and Methods MATISSE was a randomized, open-label, adaptive phase III study. Previously untreated patients with ES SCLC were randomly assigned in a 1:1 fashion to receive carboplatin at area under the serum concentration-time curve 5 on day 1 plus etoposide 100 mg/m2 per day on days 1 to 3 every 21 days (CE) or carboplatin at area under the serum concentration-time curve 4 on day 1 plus etoposide 100 mg/m2 per day plus palifosfamide 130 mg/m2 per day on days 1 to 3 every 21 days (PaCE). The primary end point was overall survival. Results In all, 188 patients were enrolled; 94 patients received CE and 94 patients received PaCE. The median age on both arms was 61 years. Six cycles of chemotherapy were completed on both arms of the study by approximately 50% of the patients. Serious adverse events were documented and did not differ significantly between patients receiving PaCE and those receiving CE. Median overall survival was similar between both arms with 10.03 months on PaCE and 10.37 months on CE ( P = .096). Conclusion The addition of palifosfamide to CE failed to improve survival in ES SCLC.

Purpose Palifosfamide is the active metabolite of ifosfamide and does not require prodrug activation, thereby avoiding the generation of toxic metabolites. The PICASSO III trial compared doxorubicin plus palifosfamide with doxorubicin plus placebo in patients who had received no prior systemic therapy for metastatic soft tissue sarcoma. Patients and Methods Patients were randomly assigned 1:1 to receive doxorubicin 75 mg/m2 intravenously day 1 plus palifosfamide 150 mg/m2/d intravenously days 1 to 3 or doxorubicin plus placebo once every 21 days for up to six cycles. The primary end point was progression-free survival (PFS) by independent radiologic review. Results In all, 447 patients were randomly assigned to receive doxorubicin plus palifosfamide (n = 226) or doxorubicin plus placebo (n = 221). Median PFS was 6.0 months for doxorubicin plus palifosfamide and 5.2 months for doxorubicin plus placebo (hazard ratio, 0.86; 95% CI, 0.68 to 1.08; P = .19). Median overall survival was 15.9 months for doxorubicin plus palifosfamide and 16.9 months for doxorubicin plus placebo (hazard ratio, 1.05; 95% CI, 0.79 to 1.39; P = .74). There was a higher incidence of grade 3 to 4 adverse events in the doxorubicin plus palifosfamide arm (63.6% v 50.9%) including a higher rate of febrile neutropenia (21.4% v 12.6%). Conclusion No significant difference in PFS was observed in patients receiving doxorubicin plus palifosfamide compared with those receiving doxorubicin plus placebo. The observed median PFS and overall survival in this large, international study can serve as a benchmark for future studies of doxorubicin in metastatic soft tissue sarcoma.

Major obstacles to developing effective immunotherapy are the ability of tumors to escape the immune system and the toxicity associated with systemic administration. To overcome these challenges, a gene delivery platform technology, RheoSwitch Therapeutic System (RTS), has been developed to enable the regulated expression of a target gene, Ad-RTS-IL-12, administered intratumorally, where IL-12 expression is controlled via the administration of an oral activator ligand, veledimex. Pharmacokinetics in healthy human subjects indicated that veledimex plasma exposure increased with increasing dose after single- and multiple-dose administration in Labrasol slurry and F-22 capsule formulations. No apparent formulation or sex-related difference in veledimex pharmacokinetics (PK) was observed. Minimal or no plasma accumulation of veledimex was observed after once-daily oral administration for 14 days. Veledimex steady state in plasma was reached after 5 daily doses. Food consumption prior to veledimex administration prolonged and enhanced absorption with no impact on the elimination rate and extent of metabolism of veledimex, resulting in significantly increased systemic exposure to veledimex and its 2 major circulating metabolites. Overall, veledimex was well tolerated and exhibited a PK profile supportive of once-daily dosing. For enhanced efficacy, veledimex should be taken under fed conditions to ensure optimal absorption and sufficient systemic exposure.

BackgroundAlternative treatment of dehydration is needed when intravenous (IV) or oral rehydration therapy fails. Subcutaneous (SC) hydration facilitated by recombinant human hyaluronidase offers an alternative treatment for dehydration. This clinical trial is the first to compare recombinant human hyaluronidase-facilitated SC (rHFSC) rehydration with standard IV rehydration for use in dehydrated children.ObjectiveThis Phase IV noninferiority trial evaluated whether rHFSC fluid administration can be given safely and effectively, with volumes similar to those delivered intravenously, to children who have mild to moderate dehydration.MethodsThe study included mild to moderately dehydrated children (Gorelick dehydration score) aged 1 month to 10 years. They were randomized to receive 20 mL/kg of isotonic fluids using rHFSC or IV therapy over 1 hour and then as needed until clinically rehydrated. The primary outcome was total volume of fluid administered (emergency department [ED] plus inpatient hospitalization). Secondary outcomes included mean volume infused in the ED alone, postinfusion dehydration scores and weight changes, line placement success and time, safety, and provider and parent/guardian questionnaire.Results148 patients (mean age, 2.3 [1.91] years]; white, 53.4%; black, 31.8%) were enrolled in the intention-to-treat population (73 rHFSC; 75 IV). The primary outcome, mean total volume infused, was 365.0 (324.6) mL in the rHFSC group over 3.1 hours versus 455.8 (597.4) mL in the IV group over 6.6 hours (P = 0.51). The secondary outcome of mean volume infused in the ED alone was 334.3 (226.40) mL in the rHFSC group versus 299.6 (252.33) mL in the IV group (P = 0.03). Dehydration scores and weight changes postinfusion were similar. Successful line placement occurred in all 73 rHFSC-treated patients and 59 of 75 (78.7%) IV-treated patients (P < 0.0001). All IV failures occurred in patients aged

Introduction Recombinant human hyaluronidase facilitates subcutaneous (SC) fluid delivery, but little is known about how various access sets influence ease of administration, technical challenges (TCs), or adverse events. Methods This randomized, open-label, parallel-group trial was performed to assess the impact of catheter size (20- and 24-gauge short peripheral intravenous catheter, 27-gauge SC button), catheter material (Teflon, polyurethane), and securement method (transparent semipermeable membrane dressing [TSM], double chevron with cloth or plastic tape) on hyaluronidase-facilitated SC fluid delivery. Healthy volunteers (N = 100) were randomized to 1 of 9 access groups using a factorial design. To minimize variability, treatment was performed at a single center and standardized to 150 units of SC recombinant human hyaluronidase (HYLENEX, Baxter Healthcare Corporation) followed by 1000 mL of lactated Ringer's solution. Results The first attempt at needle insertion succeeded in 98% of subjects; the median time for first catheter placement was less than 1 minute. The median infusion time was 6.8 hours. Overall, the incidence of TCs observed (catheter kinking, dislodgment, or pullout or infusion pump alarm) was low and comparable across groups (16.7%-27.3%); however, catheter kinking, dislodgment, and pullout occurred only in groups using double- chevron securement. Infusion-site reactions (pain, 20%-75%; erythema, 17%-36%; swelling, 0%-33%) were the most common adverse events. Pain was less frequent in groups using the 27-gauge SC button (27%) or the 24-gauge catheter (20%-36%) than with the 20-gauge catheter (50%-75%). Discussion Hyaluronidase-facilitated SC fluid administration with recombinant human hyaluronidase was generally well tolerated and successfully implemented using a range of access sets. Technical challenges were not common but were further minimized with TSM securement. Infusion-site pain was mostly mild and least common with 24-gauge or smaller catheter/needles.

3038Background: Ad-RTS-hIL-12 (Ad) is a novel gene therapy candidate expressing IL-12 under the control of an orally administered activator ligand, veledimex (V), through a proprietary RheoSwitch T...

To compare pharmacokinetics and safety of recombinant human hyaluronidase (rHuPH20)-facilitated subcutaneous (SC) ceftriaxone administration versus SC ceftriaxone preceded by SC saline placebo or intravenous (IV) ceftriaxone administration.This Phase I, two-part, placebo-controlled, crossover study was conducted in 54 healthy volunteers. In Part 1 (N = 24), subjects received 1 mL rHuPH20 (150 USP units) or placebo (0.9% sodium chloride) SC, followed by 1 or 2 g ceftriaxone (10-350 mg/mL). In Part 2 (N = 30), subjects received 1 g ceftriaxone at the Part 1 maximum tolerated concentration (MTC) administered either SC - preceded by SC rHuPH20 or placebo - or IV. Subjects were monitored for adverse events (AEs); blood samples were obtained (Part 2 only) during 48 hours post-dosing for ceftriaxone bioanalysis.Part 1 primary endpoint was the SC ceftriaxone (with or without rHuPH20) MTC. Pharmacokinetic parameters were determined in Part 2. Bioequivalence was based on maximum concentration (C(max)) and area under plasma concentration-time curve (AUC).The highest SC ceftriaxone concentration tested in Part 1 (350 mg/mL) was selected as the Part 2 MTC. In Part 2, median time to maximum concentration (t(max)) was 1 hour earlier (P0.0001), and C(max) was 12% higher (P0.0001) for ceftriaxone (350 mg/mL) administered via rHuPH20-facilitated SC versus SC preceded by placebo. IV ceftriaxone led to higher C(max) and shorter t(max) values than either SC treatment. Ceftriaxone exposure (AUC) was comparable among all three treatments. At least 1 AE was experienced by 100% of subjects after SC ceftriaxone and 76% after IV; most commonly reported AEs were infusion-site reactions.Ceftriaxone AUC did not differ significantly between the three administration routes. C(max) was higher and t(max) shorter with rHuPH20-facilitated SC than SC preceded by placebo. rHuPH20-facilitated SC ceftriaxone was generally well tolerated. This study is limited by evaluation of healthy adults and absence of repeated-dose groups.

Pediatric glioblastoma has an aggressive clinical course accounting for significant morbidity and mortality among children with brain tumors. Only 10% of children with DIPG survive for 2 years following diagnosis, and less than 1% survive for 5 years. The median survival is 9 months from diagnosis. New therapies are urgently needed. Ad-RTS-hIL-12 is a novel gene therapy expressing IL-12 under the control of an oral activator ligand, veledimex, via the RheoSwitch Therapeutic System® gene switch. Intratumoral administration of Ad-RTS-hIL-12 results in targeted tumor cytotoxicity and induction of systemic T-cell memory. Ad-RTS-hIL-12 + veledimex is a treatment strategy to extend the IL-12 therapeutic window. Based on encouraging data from an ongoing phase I dose escalation trial in adults with recurrent/progressive glioma and preclinical data in a GL-261 medullary glioma mouse model, we expect significant safety margins and tolerability profile in pediatric glioma. In a phase 1 adult study, subjects received intratumoral injections of Ad-RTS-hIL-12 2x1011 viral particles during resection or administered stereotactically. Daily oral veledimex began prior to surgery or following stereotactic injection. Overall, Ad-RTS-hIL-12 + veledimex in adults was well tolerated; toxicities were predictable and reversible upon discontinuing veledimex with a correlation between veledimex dose, BBB penetration and drug related AEs. The tolerability and encouraging survival observed warrants a dose escalation pediatric trial for subjects with recurrent/progressive brain tumors. Two groups of subjects receiving Ad-RTS-hIL-12 2x1011 viral particles are planned: Arm 1 receives Ad-RTS-hIL-12 intratumorally after resection of supratentorial tumors that are unresponsive to conventional treatment or for which there is no alternative curative therapy; Arm 2 consists of stereotactic injection in subjects with DIPG post prior standard focal radiotherapy and for which a diagnostic biopsy has previously been obtained. Subjects receive BSA adjusted escalating doses of 10 or 20mg veledimex. An update will be presented.

2044 Background: Glioblastoma (GBM) is an aggressive brain tumor affecting ~74,000 people worldwide annually. Recurrent GBM patients have a median OS (mOS) of 6-7 months. OS in patients who have failed temozolomide, bevacizumab or equivalent salvage chemotherapy, is ~3-5 months. New therapies are urgently needed. Ad-RTS-hIL-12 (Ad) is a novel gene therapy expressing IL-12 under the control of an oral activator ligand, veledimex (V), through the RheoSwitch Therapeutic System. Intratumoral administration of Ad results in targeted tumor cytotoxicity and induction of systemic T cell memory. Ad + V is a treatment strategy to extend the IL-12 therapeutic window. Methods: In a multicenter Phase I dose escalation trial and expansion cohort, subjects with recurrent or progressive Grade III or IV glioma undergoing resection were injected intratumorally with Ad 2 x 1011 viral particles and daily oral V for 15 doses, beginning prior to surgery. The primary endpoint is safety and tolerability of Ad + V; secondary endpoints include OS. Results: 25 subjects were dosed in 3 dose escalation cohorts: 20 mg (n = 7), 30 mg (n = 4), and 40 mg (n = 6) and an expansion cohort of 20 mg (n = 8). Results show V crossed the blood brain-barrier with 35±5% of plasma levels detected in the brain tumor. The 20 mg dose (n = 15) had better drug compliance (86%) than the 30 mg (63%) or 40 mg (52%) cohorts and the 20 mg cohort shows better survival (mOS 12.7 months) compared to other cohorts. The frequency of related ≥Grade (G)3 AEs in the 20 mg cohort was significantly lower: 20% in 20mg, 50% in 30mg and 40 mg. In the 20 mg cohort, the most frequent AEs were transient mild flu-like symptoms seen in 12/15, G3 cytokine release syndrome in 2/15, G3 elevated ALT/AST in 1/15 and G3 lymphopenia in 3/15. All AEs reversed promptly upon discontinuing V. Conclusions: Overall, Ad + 20 mg V is well tolerated; toxicities were predictable and reversible upon discontinuing V. There is a correlation between V dose, BBB penetration and drug related AEs. The tolerability and encouraging survival observed to date warrant further investigation in a pivotal trial. A stereotactic arm and a pediatric trial in diffuse intrinsic pontine glioma patients are planned. Clinical trial information: NCT02026271.

2052Background: The prognosis of subjects with glioblastoma multiforme (GBM) after first recurrence is extremely poor with a median overall survival (OS) of approximately 90 - 160 days. New therapies are needed, thus we developed an adenoviral vector, Ad-RTS-IL-12 (AD), administered intratumorally under the control of the RheoSwitch Therapeutic System (RTS) expression platform. Gene expression and IL-12 protein production is tightly controlled by activator ligand veledimex (V) and in our mouse model of glioma we have consistently shown a dose-response and survival benefit compared to temozolamide, bevacizumab, and a PD-1 inhibitor. Methods: In a multicenter Phase I dose escalation trial, subjects with recurrent or progressive Grade III or IV glioma undergoing resection were injected intratumorally with AD 2x1011viral particles and daily oral V for 15 doses, beginning on Day 0, prior to surgery. The study primary endpoint is safety and tolerability of AD+V with secondary endpoints including OS. Results: In...

TPS3097Background: Immune-based strategies involving T-cell activation have shown significant activity in multiple tumor types. The presence of immune elements in breast cancers has prognostic and ...

The utility of immunotherapy in the treatment of glioma may be improved through combination therapies that enhance cytotoxic immune-activation while concomitantly reducing immunosuppression. We provide data in mice to support evaluation of combining controlled local interleukin 12 (IL-12) administration and blockade of programmed cell death protein 1 (PD-1) in humans. To circumvent challenges surrounding the uncontrolled activation, we have implemented clinical trials using a replication-incompetent adenovirus engineered to conditionally express IL-12 (Ad-RTS-IL-12), via our RheoSwitch Therapeutic System® (RTS®) gene switch. When directly injected intra-tumorally in pre-clinical or clinical studies, IL-12 expression is “off” when devoid of the activator ligand (veledimex, V) and IL-12 production is turned “on” (in a dose-dependent manner) by oral administration of veledimex. PD-1 inhibitors using therapeutic monoclonal antibodies (mAbs) demonstrate an ability to reverse tumor immunosuppression and are effective in the treatment of some cancers. In the present pre-clinical study we assessed the effects of Ad-RTS-mIL-12+veledimex (Ad+V) alone, Ad 5×109 viral particles (vp) + V 10-30mg/m2/day for 14 days or in combination with the antiPD-1-specific mAb RMP1-14 (antiPD-1, 7.5 & 15.0 mg/m2 for 4/day for 5 days i.p.) in the orthotopic GL-261 mouse model. All mice without treatment succumb to disease progression by Day 35. Eighty days after immunotherapy, 70-80% receiving Ad +V monotherapy survived, 30-40% receiving antiPD-1 monotherapy survived and 100% receiving Ad +V 30 mg/m2 + antiPD-1 15.0 mg/m2 combination survived. There was an increase in tumor IL-12 (100 pg/mg) which was 15-times greater than that of plasma peak 5 days after Ad +V. Furthermore, the combination of Ad +V+antiPD-1 sustained peak IL-12 levels in tumor which was associated with a 100-150% increase of activated T cells in the spleen compared with the minimal changes observed with either immunotherapy alone. In addition, there was an additive reduction in regulatory T cells (FOXP3) compared with monotherapies. In summary we demonstrate that controlled local immunostimulation with IL-12 combined with inhibition of PD-1 is an attractive approach for the treatment of glioma. Since both Ad-RTS-IL-12 and mAb blocking PD-1 are clinically available, these data provide impetus for evaluating this combination immunotherapy in humans.

Background: Immune-based strategies involving T-cell activation have recently shown significant activity in multiple tumor types. The presence of immune elements in breast cancers has prognostic and predictive impact. Thus, strategies that optimize the interplay between a breast cancer and the effected individual's immune system may be therapeutic. Interleukin-12 (IL-12), a pro-inflammatory cytokine, reverses immune escape mechanisms induced by myeloid derived suppressor and dendritic cells which, in turn, improves the function of activated CD8+ T cells and promotes tumor stroma collapse. Because tumor neoantigens may be generated in response to chemotherapy, IL12-mediated immune modulation may be optimal in patients with chemotherapy-sensitive metastatic breast cancer. Ad-RTS-hIL-12 (Ad) is a novel gene therapy candidate expressing IL-12 under the control of an orally-administered activator ligand, veledimex (V) through the proprietary RheoSwitch Therapeutic System® (RTS). Trial Design: Open-label, phase 1b/2, single-arm, single-center study of Ad+V in women with stable or responsive disease after ≥ 12-weeks of 1st or 2nd-line chemotherapy. Eligible patients will be placed on chemotherapy-holiday and enter the immunotherapy phase, consisting of a single cycle of Ad administered intratumorally (Day 1), along with V (80 mg QDx7). HER2-directed antibody therapy may be continued during the immunotherapy phase for women with HER2- disease. Key Eligibility Criteria: Women ≥18 years with histologically-confirmed locally advanced or metastatic breast cancer of any subtype who have achieved a partial response (PR) or stable disease (SD) to 1st or 2nd-line chemotherapy are eligible. Exclusion criteria include use of immunosuppressive drugs, compromised immune function, autoimmune disorder, or brain metastases. Specific Aims: To evaluate the safety and tolerability of Ad+V immunotherapy in eligible women. Secondary endpoints include 12 week overall response rate, 12 week disease control rate and the impact of treatment on exploratory immune biomarkers. Statistical Methods: Safety and efficacy will be evaluated separately for HER2-/HER2+ patients. Tumor response will be evaluated by RECIST v1.1 at 6 and 12 weeks. To ensure safety, stopping rules defined by grade 3/4 adverse events and12-week progression rate were adopted. Target Accrual: Up to 40 patients, including up to 8 patients (20%) with HER2+ disease. Summary: Ad+V is a novel gene therapy which controls local expression of IL-12 and may induce tumor stroma collapse and stimulation of an anti-cancer T cell immune response. The ability to regulate the production of IL-12 by modulating V dosing may result in an improved therapeutic index in combination with standard of care. The data from this study will directly inform future studies. Study Contact (Clinical Trials.gov: NCT02423902). Citation Format: McArthur HL, Page D, Proverbs-Singh T, Solomon S, Hudis C, Norton L, Patil S, Barrett JA, Lebel F. Phase 1b/2 study of intratumoral Ad-RTS-hIL-12 + veledimex in patients with chemotherapy-responsive locally advanced or metastatic breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr OT1-01-05.

Immunotherapy is an attractive approach for cancer therapy. We have developed a replication-incompetent adenovirus engineered to express IL-12 (Ad-RTS-IL-12), via our RheoSwitch Therapeutic System® (RTS®) gene switch, injected directly into a tumor. IL-12 expression is “off” devoid of the activator ligand, veledimex, while IL-12 production is turned “on” (in a dose-dependent manner) by oral administration of veledimex. Veledimex had good bioavailability in mice (> 53%) following oral administration with apparent terminal half-life of 6-8 hours. In normal mice with intact blood brain barrier (BBB), dose-related increases in veledimex exposure were exhibited in brain tissue with approximately 1% plasma exposure in cerebral spinal fluid, which thereby demonstrated that veledimex crossed the BBB in mice. Mechanistic studies in numerous syngeneic mouse tumor models with Ad-RTS-mIL-12+veledimex have demonstrated a dose-related increase in tumor IL-12 mRNA and IL-12 protein expression. Discontinuation of veledimex resulted in a return to baseline IL-12 mRNA and protein expression. The ability to treat tumors at different physical locations derived from the same tumor lineage was studied in melanoma, colon cancer and glioma syngeneic mouse models. In a B16 mouse melanoma model, 1e6 melanoma cells were placed in both flanks. When the tumors reached 100mm3 one tumor was administered Ad-RTS-mIL-12 (1e10vp) + veledimex administered at ~675mg/m2/day ad lib in the chow). The results of this study showed > 90% tumor growth reduction in both the treated and untreated tumors when compared to control. In the second study, 1e6 CT26-LUC colon cancer cells were placed in the right flank with tumor growth monitored using bioluminescence imaging. On Day 15 Ad-RTS-mIL-12 (1e10vp) was administered intratumorally + veledimex at ~675mg/m2/day ad lib in the chow. On Day 43, 60% were tumor free and remaining mice had smaller tumors. When these mice were rechallenged with CT26-LUC cells in the contralateral flank no tumor growth was observed versus age matched controls for > 21days (end of study). In the glioma study, 1e5 GL-261 cells were implanted in the brain and 5 days later mice were treated with a single cycle of Ad-RTS-mIL-12 (1e10vp) administered intratumoral + veledimex 450mg/m2/day, po. QDx14. Vehicle cohorts all succumbed to the disease by Day 30. The 12 surviving animals from the treatment group on Day 100 were reinoculated with 1e5 GL-261 cells at the same site and survival monitored for an additional 80 days vs. age matched controls. We found >95% of the pretreated animals survived for an additional 80 days (end of study) vs. ~40% of the control animals. Similar results have been observed in patients with metastatic melanoma and breast cancer where nontreated lesions were also observed to decrease in size In summary, these results demonstrate this novel regulated immunotherapeutic approach may be an effective form of therapy for both primary and metastatic tumors with the same tumor lineage in melanoma, colon cancer and glioma. Further studies are planned in other tumor populations. Citation Format: John A. Barrett, Tim Chan, Hongliang Cai, John Miao, Suma Krishnan, Francois Lebel. Demonstration of systemic antitumor immunity via intratumoral regulated expression of IL-12 as a gene therapy approach to treatment of cancer. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr B091.

This paper describes improvements to the control of a high pressure, aeroderivative industrial gas turbine in order to better accommodate rapid load changes. In such circumstances it is important to maintain the speed of the driven equipment within an acceptable range. This can require the gas turbine to quickly adjust to the new load, to minimize the power imbalance, which is the cause of the speed variation. The paper describes the theory behind control schedules required to achieve this, and how they relate to avoiding surge, flameout or instability, while minimizing speed variations of the driven equipment. A whole engine thermodynamic model coupled to the control software was used to simulate the engine response during these rapid transients. The features of this model are described. The model allowed optimization of the control software in advance of the engine test. Results of whole engine tests are presented and compared to the model; and the types of load steps that remain most challenging are highlighted. The resulting capability remains partly determined by the specifics of the application, for example the inertia of the driven equipment, the nominal speed of operation, and the allowable speed variations. The effects of these can be predicted using the model and are discussed.

Immunotherapy is an attractive approach for glioma therapy. We have developed a replication-incompetent adenovirus engineered to express IL-12 (Ad-RTS-IL-12), via our RheoSwitch Therapeutic System® (RTS®) gene switch, injected directly into a tumor. IL-12 expression is "off" devoid of the activator ligand, veledimex, while IL-12 production is turned "on" (in a dose-dependent manner) by oral administration of veledimex. Mechanistic studies in numerous syngeneic mouse tumor models with Ad-RTS-mIL-12 + veledimex have demonstrated a dose-related increase in tumor IL-12 mRNA and IL-12 protein expression. Discontinuation of veledimex resulted in a return to baseline IL-12 mRNA and protein expression. These changes correlated with a local and systemic immune and anti-tumor response. Veledimex crossed the blood-brain-barrier in both naive and orthotopic GL-261 mice with increased brain tissue level of ∼6 fold observed in tumor bearing vs. normal mice (1950 ± 573 and 324 ± 51ng/g). Based on these findings the effects of Ad-RTS-mIL-12(5e9vp) + veledimex were studied in the following cohorts; dexamethasone, bevacizumab, temozolamide and CD279 (PD-1 inhibitor). Ad-RTS-mIL-12 + veledimex demonstrated a dose-related increase in survival without significant adverse events. At Day 92 (study termination), 50% of the animals that received veledimex at 100mg/m2/day for 14 consecutive days were alive and tumor free with peak tumor IL-12 at Day 3 of ∼240pg/mg. In contrast, the mean survival for the other groups were: vehicle 18d, dexamethasone 24d, bevacizumab 25d, temozolamide 40d and CD279 38d demonstrating that this novel regulated immunotherapeutic approach may be an effective form of therapy for glioma. A Phase 1 study of Ad-RTS-hIL-12 + veledimex in patients with recurrent or progressive malignant glioma are stratified into two groups: resection plus localized injection or stereotactic injection (3D-located) of Ad-RTS-hIL-12 (single intratumoral injection) + veledimex 14 days (oral) has initiated. The primary endpoint is the safety and tolerability of Ad-RTS-hIL-12 + veledimex with secondary endpoints of MTD, immune response, objective response rate, disease progression, progression-free and overall survival.