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PURPOSE Patients with metastatic urothelial carcinoma are often ineligible for cisplatin-based treatments. A National Cancer Institute Cancer Therapy Evaluation Program–sponsored trial assessed the tolerability and efficacy of a gemcitabine-eribulin combination in this population. METHODS Patients with treatment-naïve advanced or recurrent metastatic urothelial carcinoma of the bladder, ureter, or urethra not amenable to curative surgery and not candidates for cisplatin-based therapy were eligible. Cisplatin ineligibility was defined as creatinine clearance less than 60 mL/min (but ≥ 30 mL/min), grade 2 neuropathy, or grade 2 hearing loss. Treatment was gemcitabine 1,000 mg/m2 intravenously followed by eribulin 1.4 mg/m2, both on days 1 and 8, repeated in 21-day cycles until progression or unacceptable toxicity. A Simon two-stage phase II trial design was used to distinguish between Response Evaluation Criteria in Solid Tumors, version 1.1 objective response rates of 20% versus 50%. RESULTS Between June 2015 and March 2017, 24 eligible patients with a median age of 73 years (range, 62 to 88 years) underwent therapy. Performance status of 0, 1, or 2 was seen in 11, 11, and two patients, respectively. Sites of disease included: lymph nodes, 16; lungs, nine; liver, seven; bladder, five; bones, two. Median number of cycles received was four (range, one to 16). Of 24 patients, 12 were confirmed responders; the observed objective response rate was 50% (95% CI, 29% to 71%). Median overall survival was 11.9 months (95% CI, 5.6 to 20.4 months), and median progression-free survival was 5.3 months (95% CI, 4.5 to 6.7 months). The most common treatment-related any-grade toxicities were fatigue (83% of patients), neutropenia (79%), anemia (63%), alopecia (50%), elevated AST (50%), and constipation, nausea, and thrombocytopenia (42% each). CONCLUSION Gemcitabine-eribulin treatment response and survival for cisplatin-ineligible patients compare favorably to other regimens. Additional research is needed.

4529 Background: Immune checkpoint blockade has revolutionized mRCC Tx, but primary and acquired resistance continues to result in poor patient outcomes. OX40 (CD-134) mediates IO resistance. Co-stimulatory OX40 (CD-134) activates exhausted T-cells. OX40 activation in dendritic cells increases the proliferation, effector function, and survival of T cells. PFOX is an agonist for OX40. We hypothesized that PFOX + the VEGFR inhibitor Axi would improve outcomes vs. Axi in patients (pts) with mRCC after IO Tx. Methods: Pts with predominantly clear cell mRCC were stratified for MSKCC risk groups then randomized 1:1 to Axi 5mg po bid plus PFOX 0.3mg/kg iv (Arm 1) or placebo (PL) iv (Arm 2) on Day 1 of a 2-week cycle. The primary endpoint was progression free survival (PFS); secondary endpoints included overall survival (OS), objective response rate (ORR), duration of response (DOR) per RECIST v1.1, and safety/tolerability. A prespecified interim analysis (IA) tested PFS at a 1-sided P < 0.02 when ≥ 33 events were observed. Results: Between February 2018 and October 2021 a total of 59 pts were randomly assigned and treated with Axi+PFOX (N = 29) or Axi+PL (N = 30). Pt and disease characteristics are summarized in the table. As of October 2021, 38 PFS events had occurred, 19 on each arm. The IA rejected the hypothesis of added efficacy for PFOX with a p of 0.0089. Subsequently the study was closed to new accrual. At a median follow up of 13.4 mo, median PFS was 13.1 (6-15.8) months (mo) for Arm 1 and 8.5 (5.5-11) mo for Arm 2 (HR = 0.85 [95% CI: 0.45-1.60] p = 0.61). After adjusting by MSKCC risk group and prior lines of Tx, HR = 0.74 [95% CI: 0.38-1.46] p = 0.39. Median OS was not reached (adjusted HR = 0.71 [95% CI: 0.24-2.12] p = 0.54). ORR Arm 1: 31% PR, 52% SD, 14% PD, and Arm 2: 37% PR, 50% SD, 13% PD. Median DOR 9.1 (3.3-23.9) mo for Arm 1, and 7.5 (1.8-32.7) mo. for Arm 2. Rates of any grade Tx related adverse events (TRAEs; 93% vs 100%), including grade 3 or 4 TRAEs (66% vs 47%), in Arm 1 and Arm 2, respectively. 4 pts discontinued Tx due to TRAE, 3 in Arm 1 (1 grade 3 hypertension, 1 grade 2 stroke, 1 grade 3 bullous dermatitis) and 1 in Arm 2 (grade 4 ALT elevation). The most common TRAEs were diarrhea 52%, hypertension 52%, fatigue 41%, nausea 41% for Arm 1 and hypertension 67%, diarrhea 53%, fatigue 50% for Arm 2. Conclusions: In IO-pretreated mRCC pts, Axi + PFOX did not improve outcomes compared to Axi alone. Clinical trial information: NCT03092856. [Table: see text]

We hypothesized that GTI-2040, a 20-mer oligonucleotide complementary to the R2 subunit mRNA of ribonucleotide reductase, combined with high dose cytarabine (HiDAC) would result in enhanced cytotoxicity by favoring Ara-CTP DNA incorporation. In a phase I dose escalation trial, adults (≥ 60 years) with refractory or relapsed acute myeloid leukemia (AML) received daily HiDAC plus infusional GTI-2040. Using a novel assay, evidence of intracellular drug accumulation and target R2 down-regulation was observed. GTI-2040/HiDAC can be administered safely. However, with no complete remissions observed, alternative doses and schedules may need to be investigated to achieve clinical activity in older patients with AML.

We recently reported promising clinical activity for a 10-day regimen of decitabine in older AML patients; high miR-29b expression associated with clinical response. Subsequent preclinical studies with bortezomib in AML cells have shown drug-induced miR-29b up-regulation, resulting in loss of transcriptional activation for several genes relevant to myeloid leukemogenesis, including DNA methyltransferases and receptor tyrosine kinases. Thus, a phase 1 trial of bortezomib and decitabine was developed. Nineteen poor-risk AML patients (median age 70 years; range, 32-84 years) enrolled. Induction with decitabine (20 mg/m2 intravenously on days 1-10) plus bortezomib (escalated up to the target 1.3 mg/m2 on days 5, 8, 12, and 15) was tolerable, but bortezomib-related neuropathy developed after repetitive cycles. Of previously untreated patients (age ≥ 65 years), 5 of 10 had CR (complete remission, n = 4) or incomplete CR (CRi, n = 1); 7 of 19 overall had CR/CRi. Pharmacodynamic analysis showed FLT3 down-regulation on day 26 of cycle 1 (P = .02). Additional mechanistic studies showed that FLT3 down-regulation was due to bortezomib-induced miR-29b up-regulation; this led to SP1 down-regulation and destruction of the SP1/NF-κB complex that transactivated FLT3. This study demonstrates the feasibility and preliminary clinical activity of decitabine plus bortezomib in AML and identifies FLT3 as a novel pharmacodynamic end point for future trials. This study is registered at http://www.clinicaltrials.gov as NCT00703300.

Bevacizumab is a humanized recombinant monoclonal antibody that neutralizes vascular endothelial growth factor, an agent with proangiogenic effects in melanoma. Interferon alpha (IFN-α) has antiangiogenic properties through its ability to downregulate basic-fibroblast growth factor levels. We hypothesized that the coadministration of these agents would lead to tumor regression. Patients with metastatic melanoma received bevacizumab 15 mg/kg intravenously on day 1 of the 2-week cycle. IFN-α was administered thrice weekly at 5 MU/m subcutaneously during cycle 1 and was increased to 10 MU/m during cycle 2. Patients were restaged every 6 cycles. Patients with stable disease or a response continued with therapy. Baseline serum vascular endothelial growth factor and fibroblast growth factor were measured. Twenty-five patients were accrued. Mean age was 58.4 years. Eleven patients required IFN-α dose reductions due to toxicity. Common grade 3 toxicities associated with IFN-α included fatigue and myalgia. Bevacizumab administration was associated with grade 2-3 proteinuria in 6 patients. Grade 4 adverse events were pulmonary embolus (1), myocardial infarction (1), and stroke (1). Six patients had a partial response, and 5 patients exhibited stable disease that lasted more than 24 weeks (range: 30 to 122 wk). Median progression-free survival and overall survival were 4.8 and 17 months, respectively. Significantly lower fibroblast growth factor levels were observed in patients with a partial response compared to those with stable or progressive disease (P=0.040). Administration of bevacizumab with IFN led to a clinical response in 24% of patients with stage IV melanoma and stabilization of disease in another 20% of patients. This regimen has activity in advanced melanoma.

Purpose Lenalidomide is effective in myeloma and low-risk myelodysplastic syndromes with deletion 5q. We report results of a phase I dose-escalation trial of lenalidomide in relapsed or refractory acute leukemia. Patients and Methods Thirty-one adults with acute myeloid leukemia (AML) and four adults with acute lymphoblastic leukemia (ALL) were enrolled. Lenalidomide was given orally at escalating doses of 25 to 75 mg daily on days 1 through 21 of 28-day cycles to determine the dose-limiting toxicity (DLT) and maximum-tolerated dose (MTD), as well as to provide pharmacokinetic and preliminary efficacy data. Results Patients had a median age of 63 years (range, 22 to 79 years) and a median of two prior therapies (range, one to four therapies). The DLT was fatigue; 50 mg/d was the MTD. Infectious complications were frequent. Plasma lenalidomide concentration increased proportionally with dose. In AML, five (16%) of 31 patients achieved complete remission (CR); three of three patients with cytogenetic abnormalities achieved cytogenetic CR (none with deletion 5q). Response duration ranged from 5.6 to 14 months. All responses occurred in AML with low presenting WBC count. No patient with ALL responded. Two of four patients who received lenalidomide as initial therapy for AML relapse after allogeneic transplantation achieved durable CR after development of cutaneous graft-versus-host disease, without donor leukocyte infusion. Conclusion Lenalidomide was safely escalated to 50 mg daily for 21 days, every 4 weeks, and was active with relatively low toxicity in patients with relapsed/refractory AML. Remissions achieved after transplantation suggest a possible immunomodulatory effect of lenalidomide, and results provide enthusiasm for further studies in AML, either alone or in combination with conventional agents or other immunotherapies.

Patients with acute myeloid leukemia (AML) frequently fail chemotherapy due to refractory disease, relapse, or toxicity. Among older AML patients (age > 60 years), there are few long-term survivors. Lenalidomide is a candidate for study in AML based on its clinical activity in a related disorder, myelodysplastic syndrome (MDS), with the 5q− chromosomal abnormality. We report induction of sustained morphologic and cytogenetic complete remission in 2 older AML patients treated with high-dose, single-agent lenalidomide; each patient had trisomy 13 as the sole cytogenetic abnormality. We show for the first time that lenalidomide has clinical activity in this poor-risk cytogenetic subset of AML. The clinical trials described in this paper have been registered with www.clinicaltrials.gov under identifiers NCT00466895 and NCT00546897.

Purpose: Inhibition of ribonucleotide reductase reduces the availability of the endogenous pool of deoxycytidine and may increase cytarabine (AraC) cytotoxicity. We performed a phase I dose escalation trial of AraC combined with GTI-2040, a 20-mer antisense oligonucleotide shown in preclinical studies to decrease levels of the R2 subunit of ribonucleotide reductase, to determine the maximum tolerated dose in adults with relapsed/refractory acute myeloid leukemia. Experimental Design: Twenty-three adults (ages 18-59 years) were enrolled in this dose escalation phase I trial, receiving high-dose AraC twice daily combined with infusional GTI-2040. An ELISA-based assay measured plasma and intracellular concentrations of GTI-2040. R2 protein changes were evaluated by immunoblotting in pretreatment and post-treatment bone marrow samples. Results: The maximum tolerated dose was 5 mg/kg/d GTI-2040 (days 1-6) and 3 g/m2/dose AraC every 12 hours for 8 doses. Neurotoxicity was dose limiting. Eight patients (35%) achieved complete remission. Mean bone marrow intracellular concentration of GTI-2040 were higher at 120 hours than at 24 hours from the start of GTI-2040 (P = 0.002), suggesting intracellular drug accumulation over time. Reductions in bone marrow levels of R2 protein (>50%) were observed at 24 and 120 hours. Higher baseline R2 protein expression (P = 0.03) and reductions after 24 hours of GTI-2040 (P = 0.04) were associated with complete remission. Conclusions: GTI-2040 and high-dose AraC were coadministered safely with successful reduction of the intended R2 target and encouraging clinical results. The clinical efficacy of this combination will be tested in an upcoming phase II study.

PurposeLenalidomide is a novel therapeutic agent with uncertain mechanism of action that is clinically active in myelodysplastic syndrome (MDS) and multiple myeloma (MM). Application of high (MM) and low (MDS) doses of lenalidomide has been reported to have clinical activity in CLL. Herein, we highlight life-threatening tumor flare when higher doses of lenalidomide are administered to patients with CLL and provide a potential mechanism for its occurrence.Patients and MethodsFour patients with relapsed CLL were treated with lenalidomide (25 mg/d for 21 days of a 28-day cycle). Serious adverse events including tumor flare and tumor lysis are summarized. In vitro studies examining drug-induced apoptosis and activation of CLL cells were also performed.ResultsFour consecutive patients were treated with lenalidomide; all had serious adverse events. Tumor flare was observed in three patients and was characterized by dramatic and painful lymph node enlargement resulting in hospitalization of two patients, with one fatal outcome. Another patient developed sepsis and renal failure. In vitro studies demonstrated lenalidomide-induced B-cell activation (upregulation of CD40 and CD86) corresponding to degree of tumor flare, possibly explaining the tumor flare observation.ConclusionLenalidomide administered at 25 mg/d in relapsed CLL is associated with unacceptable toxicity; the rapid onset and adverse clinical effects of tumor flare represent a significant limitation of lenalidomide use in CLL at this dose. Drug-associated B-cell activation may contribute to this adverse event. Future studies with lenalidomide in CLL should focus on understanding this toxicity, investigating patients at risk, and investigating alternative safer dosing schedules.

This phase I study was conducted to determine the maximum tolerated dose (MTD) and dose limiting toxicities (DLTs) of the heat shock protein 90 (HSP90) inhibitor 17-allyamino-17-demethoxygeldanamycin (17-AAG) in combination with bortezomib, and to provide pharmacokinetic data in relapsed or refractory acute myeloid leukemia (AML). Eleven patients were enrolled. The MTD was 17-AAG 150 mg/m(2) and bortezomib 0.7 mg/m(2). Hepatic toxicity and cardiac toxicity were dose limiting. Co-administration on day 4 led to a decrease in clearance (p = 0.005) and increase in AUC (p = 0.032) of 17-amino-17-demethoxygeldanamycin (17-AG), not observed when 17-AAG was administered alone. Pharmacokinetic parameters of patients who developed toxicities and those who did not were not different. The combination of 17-AAG and bortezomib led to toxicity without measurable response in patients with relapsed or refractory AML. Pharmacokinetic data provide insight for studies of related agents in AML. Next-generation HSP90 inhibitors are appealing for further development in this area.

Summary Ribonucleotide reductase M2 subunit (RRM2) plays a key role in repairing radiationinduced DNA damage. Preclinical data suggest radiosensitizing properties for triapine, an RRM2 inhibitor. Weperformedaphase1study of triapine and radiation in locally advanced pancreas cancer. In this study, 92% of patients experienced freedom fromlocaltumor progression, confirming the clinical significance of the radiosensitizing effect of triapine. Correlative analyses suggest that dynamic contrastPurpose: Triapine, a novel inhibitor of the M2 subunit of ribonucleotide reductase (RR), is a potent radiosensitizer. This phase 1 study, sponsored by the National Cancer Institute Cancer Therapy Evaluation Program, assessed the safety and tolerability of triapine in combination with radiation (RT) in patients with locally advanced pancreas cancer (LAPCA). Methods and Materials: We evaluated 3 dosage levels of triapine (24 mg/m 2 , 48 mg/m 2 ,7 2 mg/m 2 ) administered with 50.4 Gy of RT in 28 fractions. Patients with LAPCA received triapine thrice weekly, every other week during the course of RT. Dose-limiting toxicity (DLT) was assessed during RT and for 4 weeks after its completion. Dynamic contrast-enhanced magnetic resonance imaging and serum RR levels were evaluated as potential predictors for early response. Results: Twelve patients were treated. Four patients (1 nonevaluable) were enrolled at dosage level 1 (DL1), 3 patients at DL2, and 5 patients (2 nonevaluable) at DL3. No DLTs were observed, and the maximum tolerated dose was not reached. Two patients (17%) achieved partial response, and 6patients (50%)had stabledisease.Onepatientunderwent R0resection aftertherapy. Ninetytwopercent ofpatients (100%atDL3)experienced freedomfromlocaltumorprogression. In75% of patients who eventually experienced progression, metastases developed without local progression.RRlevelsdidnotseemtopredictoutcome.In4patientswithavailabledata,dynamiccontrastenhanced magnetic resonance imaging may predict early response or resistance to therapy. Conclusion: The combination of triapine at 72 mg/m 2 3 times weekly every other week and stan

Background A pharmacokinetically derived schedule of flavopiridol administered as a 30 min intravenous bolus followed by 4-hour continuous intravenous infusion (IVB/CIVI) is active in fludarabine-refractory chronic lymphocytic leukemia, but no studies examining the feasibility and maximum tolerated dose of this schedule have been reported in acute leukemia. Design and Methods We conducted a phase I dose escalation trial of single-agent flavopiridol in adults with relapsed/refractory acute leukemias, utilizing a modification of the intravenous bolus/continuous intravenous infusion approach, intensifying treatment for administration on days 1, 2, and 3 of 21-day cycles. Results Twenty-four adults with relapsed/refractory acute myeloid leukemia (n=19) or acute lymphoblastic leukemia (n=5) were enrolled. The median age was 62 years (range, 23–78). The maximum tolerated dose of flavopiridol was 40mg/m2 intravenous bolus plus 60mg/m2 continuous intravenous infusion (40/60). The dose limiting toxicity was secretory diarrhea. Life-threatening hyperacute tumor lysis syndrome requiring hemodialysis on day 1 was observed in one patient. Pharmacokinetics were dose-dependent with increased clearance observed at the two highest dose levels. Diarrhea occurrence and severity significantly correlated with flavopiridol concentrations at the end of the 4-hour infusion, volume of distribution, and elimination half-life. Modest anti-leukemic activity was observed, with most patients experiencing dramatic but transient reduction/clearance of circulating blasts lasting for 10–14 days. One refractory acute myeloid leukemia patient had short-lived complete remission with incomplete count recovery. Conclusions Flavopiridol as a single agent given by intravenous bolus/continuous intravenous infusion causes marked, immediate cytoreduction in relapsed/refractory acute leukemias, but objective clinical responses were uncommon. With this schedule, the dose is limited by secretory diarrhea ( ClinicalTrials.gov Identifier: [NCT00101231][1] ). [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT00101231&atom=%2Fhaematol%2F95%2F7%2F1098.atom

A phase II clinical trial with single-agent decitabine was conducted in older patients (≥60 years) with previously untreated acute myeloid leukemia (AML) who were not candidates for or who refused intensive chemotherapy. Subjects received low-dose decitabine at 20 mg/m 2 i.v. over 1 h on days 1 to 10. Fifty-three subjects enrolled with a median age of 74 years (range, 60–85). Nineteen (36%) had antecedent hematologic disorder or therapy-related AML; 16 had complex karyotypes (≥3 abnormalities). The complete remission rate was 47% ( n = 25), achieved after a median of three cycles of therapy. Nine additional subjects had no morphologic evidence of disease with incomplete count recovery, for an overall response rate of 64% ( n = 34). Complete remission was achieved in 52% of subjects presenting with normal karyotype and in 50% of those with complex karyotypes. Median overall and disease-free survival durations were 55 and 46 weeks, respectively. Death within 30 days of initiation of treatment occurred in one subject (2%), death within 8 weeks in 15% of subjects. Given the DNA hypomethylating effect of decitabine, we examined the relationship of clinical response and pretreatment level of miR-29b , previously shown to target DNA methyltransferases. Higher levels of miR-29b were associated with clinical response ( P = 0.02). In conclusion, this schedule of decitabine was highly active and well tolerated in this poor-risk cohort of older AML patients. Levels of miR-29b should be validated as a predictive factor for stratification of older AML patients to decitabine treatment.

Purpose To determine an optimal biologic dose (OBD) of decitabine as a single agent and then the maximum-tolerated dose (MTD) of valproic acid (VA) combined with decitabine in acute myeloid leukemia (AML). Patients and Methods Twenty-five patients (median age, 70 years) were enrolled; 12 were untreated and 13 had relapsed AML. To determine an OBD (based on a gene re-expression end point), 14 patients received decitabine alone for 10 days. To determine the MTD, 11 patients received decitabine (at OBD, days 1 through 10) plus dose-escalating VA (days 5 through 21). Results The OBD of decitabine was 20 mg/m2/d intravenously, with limited nonhematologic toxicity. In patients treated with decitabine plus VA, dose-limiting encephalopathy occurred in two of two patients at VA 25 mg/kg/d and one of six patients at VA 20 mg/kg/d. Drug-induced re-expression of estrogen receptor (ER) was associated with clinical response (P ≤ .05). ER promoter demethylation, global DNA hypomethylation, depletion of DNA methyltransferase enzyme, and histone hyperacetylation were also observed. In an intent-to-treat analysis, the response rate was 44% (11 of 25). Of 21 assessable patients, 11 (52%) responded: four with morphologic and cytogenetic complete remission (CR; each had complex karyotype), four with incomplete CR, and three with partial remission. In untreated AML, four of nine assessable patients achieved CR. Clinical responses appeared similar for decitabine alone or with VA. Conclusion Low-dose decitabine was safe and showed encouraging clinical and biologic activity in AML, but the addition of VA led to encephalopathy at relatively low doses. On the basis of these results, additional studies of decitabine (20 mg/m2/d for 10 days) alone or with an alternative deacetylating agent are warranted.

Vascular endothelial growth factor (VEGF) is a proangiogenic molecule produced by melanoma cells. We hypothesized that administration of bevacizumab (Bev), a monoclonal antibody that neutralizes VEGF, with low-dose interferon alfa-2b (IFN-alpha2b), an inhibitor of basic fibroblast growth factor (FGF), would lead to the regression of metastatic melanoma.Patients with metastatic melanoma were randomized to receive Bev (15 mg/kg intravenously every 2 weeks) with or without low-dose IFN-alpha2b (1 MU/m2 subcutaneously daily). Patients exhibiting a clinical response or stable disease after 12 weeks were treated until disease progression.Thirty-two patients (16 per arm) were accrued (18 male, 14 female; mean age 57.5 years). Both regimens were well tolerated. Six patients developed easily managed exacerbations of preexisting hypertension. Two patients developed grade 3 proteinuria that resolved after a treatment break. IFN-alpha2b therapy was associated with grade 1 to 2 constitutional symptoms. Arterial thromboembolic complications were observed in three patients (two mild myocardial infarctions, one transient ischemic attack), all of whom had risk factors. One patient (Bev plus IFN-alpha2b arm) had locally recurrent scalp disease that partially responded to therapy. Eight patients (five Bev, three Bev plus IFN-alpha2b) had prolonged disease stabilization (24 to 146 weeks). Plasma levels of VEGF and FGF did not correlate with any clinical parameter. The patient with the longest period of stable disease had the highest baseline VEGF and FGF.Bev was well tolerated at this dose and prolonged disease stabilization was achieved in one-quarter of metastatic melanoma patients. Low-dose IFN-alpha2b did not augment the activity of Bev.

Purposes Pharmacologic downregulation of Bcl-2, an antiapoptotic protein overexpressed in cancer, might increase chemosensitivity in acute myeloid leukemia (AML). Herein, we investigated the feasibility of this approach in untreated elderly AML patients by administering oblimersen sodium (G3139), an 18-mer phosphorothioate antisense to Bcl-2, during induction and consolidation treatments. Patients and Methods Untreated patients with primary or secondary AML (stratified to cohort 1 or 2, respectively) who were ≥ 60 years received induction with G3139, cytarabine, and daunorubicin at one of two different dose levels (45 and 60 mg/m2) and, on achievement of complete remission (CR), consolidation with G3139 and high-dose cytarabine. An enzyme-linked immunosorbent assay (ELISA) –based assay was used to measure plasma and intracellular concentrations (IC) of G3139. Bcl-2 mRNA and protein levels were quantified by real-time reverse transcriptase polymerase chain reaction and ELISA, respectively, in bone marrow samples collected before induction treatment and after 72 hours of G3139 infusion, prior to initiation of chemotherapy. Results Of the 29 treated patients, 14 achieved CR. With a median follow-up of 12.6 months, seven patients had relapsed. Side effects of this combination were similar to those expected with chemotherapy alone and were not dose limiting at both dose levels. After 72-hour G3139 infusion, Bcl-2/ABL mRNA copies were decreased compared with baseline (P = .03) in CR patients and increased in nonresponders (NRs; P = .05). Changes in Bcl-2 protein showed a similar trend. Although plasma pharmacokinetics did not correlate with disease response, the median IC of the antisense was higher in the CR patients compared with NRs (17.0 v 4.4 pmol/mg protein, respectively; P = .05). Conclusion G3139 can be administered safely in combination with intensive chemotherapy, and the degree of Bcl-2 downmodulation may correlate with response to therapy.

Abstract 2619 Expression of miR-181a confers better prognosis in cytogenetically normal (CN) AML (Schwind et al, JCO 2010). Laboratory studies by our group have demonstrated that miR-181a is upregulated by C/EBPα-p30. CN AML patients (pts) harboring CEBPA mutations, the majority of which block C/EBPAα-p42 expression but allow C/EBPα-p30 expression, have elevated miR-181a and more favorable clinical outcome (Marcucci et al, JCO 2008). We hypothesized that pharmacologic potentiation of C/EBPa-p30 expression, and in turn miR-181a upregulation, would increase chemosensitivity and improve clinical outcomes in AML. Based on prior in vitro and in vivo studies, LEN was selected as a candidate agent to achieve these pharmacodynamic (PD) endpoints. Pharmacokinetic (PK) and PD studies from our prior single-agent, high-dose LEN trial demonstrated upregulation of miR-181a in leukemic blasts at tolerable doses; preclinical studies showed that this effect is dose dependent. Given these results and previously demonstrated LEN clinical activity in AML (Blum et al, JCO 2010; Fehniger et al, Blood 2011; Ades et al, ASH 2010; Lancet et al, ASH 2011), a phase I trial was conducted of LEN as miR “priming” with intensive chemotherapy in two parallel cohorts of AML: Prior Therapy (PT) Cohort for relapsed/refractory pts 60 years. In both groups, LEN was given for 14 days(d) starting at 25mg/d; cytarabine and idarubicin (starting dose 12/mg/m2 × 3d) began on d5. PT Cohort received cytarabine at a starting dose of 1.5 g/m2/d over 24 hours for 4d; U Cohort received 100mg/m2 for 7d in standard fashion. 31 pts enrolled, 17 with relapsed/refractory AML and 14 with previously untreated AML. PT Cohort pts had median age 53 years (range, 22–64) and median presenting WBC count of 4.2 × 109 (range, 0.9–22.7 × 109). U Cohort pts had median age 69 years (range, 48–77), median presenting WBC count of 3.1 × 109 (range, 0.5–31.9 × 109), and median marrow blasts of 36%. None of the U Cohort pts had favorable risk disease by ELN classification, 6 had adverse risk. Note that one patient 60 years) in the U Cohort. One pt in U Cohort was not evaluable for response as the pt discontinued treatment before chemotherapy was given. Preliminary PK parameters and LEN exposure (Figure 1) are consistent with what we reported previously. Observed PK of idarubicin was similar to expected and did not suggest an interaction with LEN. There was no apparent difference in PK of LEN in those who experienced skin rash (or other toxicities/clinical outcomes) compared with those that did not. Preliminary PD testing of LEN-induced modulation of miR-181a expression was consistent with the hypothesis of the trial. Results in a small subset of pts (N=6) tested to date showed a trend for greater post-LEN increase in miR-181a(pretreatment vs. d5 before chemotherapy began) in pts who achieved CR compared with those who did not (Figure 2). In conclusion, LEN priming with chemotherapy is reasonably well tolerated and active in AML. We are planning a randomized phase II study in previously untreated patients to test the hypotheses and compare efficacy of LEN priming vs. post-chemotherapy LEN. For the current trial, an amendment to shorten the course of LEN in order to facilitate dose escalation above 25mg is planned. Updated correlative results for all enrollees will be presented. Supported by NCI U01 CA 76576-05, NIH/NCI K23CA120708, Leukemia and Lymphoma Society SCOR 7004-11, and SPORE P50-CA140158. Figure 1 Figure 1. Figure 2 Figure 2. Disclosures: Off Label Use: Lenalidomide in AML.

e14558 Background: Pancreas cancer is a leading cause of cancer death in the US. Chemoradiation, a standard therapy for patients with locally advanced pancreas cancer (LAPCA), has resulted in modes...

8520 Background: Bevacizumab (Bev) is a recombinant monoclonal antibody that neutralizes vascular endothelial growth factor, a potent factor for the induction of tumor angiogenesis in melanoma. Int...

Abstract 841 Lenalidomide is effective in myeloma and low-risk myelodysplastic syndromes (MDS), especially MDS with the 5q- cytogenetic abnormality, and may also have activity in acute leukemia. We designed a phase I dose escalation trial of lenalidomide in adults with relapsed or refractory acute leukemia to determine the maximum tolerable dose (MTD) and dose limiting toxicity (DLT), as well as to provide preliminary efficacy data in this setting. 35 adults with acute leukemia were enrolled: 31 with acute myeloid leukemia (AML) and 4 with acute lymphoblastic leukemia (ALL). Patients had a median age of 63 years (range, 22-79) and had received a median of 2 prior therapies (range, 1-4). 8 patients had relapsed after transplantation (7-allogeneic, 1-autologous). Patients were treated orally with lenalidomide on days 1-21 of 28 day cycles at the following dose levels: 25mg/day (N=4), 35mg/day (N=9), 50mg/day (N=19, including the expansion at the MTD), and 75mg/day (N=3). Patients were eligible to receive additional cycles of treatment beyond cycle 1 in the absence of disease progression defined as 25% increase in blasts relative to pretreatment. The median number of cycles received was 1 (range, 1-7). DLTs were assessed during cycle 1 of therapy. DLTs were sudden death (N=1, autopsy ruled out pulmonary embolism), rash (N=1), line-associated thrombosis (N=1), and fatigue (N=3). Grade 3 fatigue occurred in two patients at 75mg/day; 50mg/day was thus declared the recommended phase 2 dose and 10 additional patients were treated at this dose. The major toxicities associated with treatment were drug and disease associated myelosuppression and infection, as expected; these did not constitute DLT. In spite of concerns that higher dose lenalidomide would be associated with increased risk of thromboembolism, this toxicity was infrequent, even during multiple cycles of therapy. Two events occurred; both were line associated, and neither was life-threatening. Detailed pharmacokinetic results for the dose escalation cohorts in the trial are listed in the table below. Maximum plasma lenalidomide concentrations and area under the concentration-time curve (AUC) increased proportionally with dose. Drug clearance was independent of dose and correlated with calculated creatinine clearance. Of 31 patients with AML there were 5 complete responses (CR) (by IWG criteria for AML; Cheson, JCO 2003). 3/3 with cytogenetically abnormal AML achieved cytogenetic CR (cCR) as well. Achievement of CR was delayed beyond 2 months from initiation of therapy in each case. The duration of CR was 2.4-8.8 months, with two responders still in CR at 2.4+ and 4.7+ months, respectively. At 25mg, a 74 year old with AML in 2nd relapse with widespread leukemia cutis but no blood/marrow involvement had resolution of disease after 2 cycles. At 35mg, a 69 year old with AML and trisomy 13 achieved cCR after 2 cycles. At 50mg, there were three CRs, including two patients who received lenalidomide as initial therapy for relapsed AML following allogeneic stem cell transplant. In both of these cases, lenalidomide therapy was associated with the onset of skin rash requiring temporary discontinuation of drug; CR was achieved after 2 to 3 cycles of therapy and was preceded by cytogenetic remission before count recovery occurred. A third CR at the 50mg level occurred in a 70 year old with AML who had lenalidomide discontinued after 2 cycles due to no apparent response. Subsequently, CR was achieved 1 month later with no intervening therapy. In conclusion, single agent lenalidomide induced CR in 16% (5/31) of relapsed/ refractory AML patients. None of the responders had 5q-. The DLT was fatigue; the MTD was 50mg daily for days 1-21. Achievement of CR without donor leucocyte infusion in 2/4 patients who received lenalidomide as initial therapy for AML relapse following allogeneic transplantation suggests a possible allogeneic immunomodulatory effect. We are now developing a CTEP-sponsored study of lenalidomide as maintenance following allogeneic transplantation for AML. The promising single agent efficacy reported here supports further study of lenalidomide in combination with other agents in high risk AML. Disclosures: Blum: Celgene: Research Funding.

7010 Background: We established an optimal daily dose of decitabine in AML at 20mg/m2/day based on re-expression of epigenetically silenced genes, with promising clinical activity seen in poor risk older patients (pts) (Blum, J Clin Oncol. 2007). Methods: We designed a phase II study of decitabine for untreated AML pts of age≥60 who were not candidates for intensive chemotherapy (or who refused it). PS was ECOG 2 IV on days 1–10 of 4 week cycles. Pts with persistent AML at the end of a cycle received a repeat of the 10 day course, but responding pts received maintenance with abbreviated courses of 3–5 days depending on degree and duration of neutropenia. Results: 33 pts had median age of 74 years (range, 60–83). 15 pts had either secondary or t-AML. Median WBC count was 2400/μL (range, 400–58,800/μL) with marrow blasts of 44% (range, 21–92%). 13 pts had complex karyotype (≥3 abnormalities); 13 had normal karyotype; one pt had t(8;21). 31/33 pts had at least 2 poor-risk factors of age ≥70, antecedent hematologic disorder, unfavorable karyotype, or ECOG 2, and 28/33 had HCT-CI scores of ≥2. 42% of pts achieved CR (14/33). 58% achieved either CR or CRi (19/33). CR occurred in all subsets of disease and cytogenetic risk groups. CR durations to date are 2–14+ months. Median time from initial response to relapse for 6 pts who relapsed after CR was 6.5 months. Median OS has not been reached; median f/u of 19 surviving pts is 8 months. The median number of cycles received to date is 5 (range, 1–10). 9 of 14 pts who achieved CR required only a single 10 day course before initial response was achieved (CR, N = 2; CRi, N = 7). For pts who had CRi as initial response, the median number of additional cycles to achievement of full CR was 1 (range, 1–3). Death within 8 weeks of any cause occurred in 15% of pts (due to infection in each case). Though non-hematologic toxicities were infrequent, infection and/or febrile neutropenia were common (in 24/33 pts). Correlative studies are ongoing. Conclusions: Decitabine in this novel schedule of induction with outcome-adapted modification of maintenance therapy was highly active in this poor risk cohort. Survival results warrant comparison with intensive therapy for pts eligible to receive it. (supported by NO1-CM62207, K23 CA120708–01, RO1CA102031) [Table: see text]

The hypomethylating agent decitabine inhibits DNA methyltransferase (DNMT) enzymatic activity and is approved by the FDA for treatment of myelodysplastic syndromes. We previously performed a phase I trial in AML of decitabine (with or without the histone deacetylase inhibitor valproic acid); the trial was designed to establish a biologically effective dose (BED) of decitabine based on drug-induced re-expression of methylated and silenced genes. With the derived BED of 20mg/m2/day given for 10 days, every 4 weeks, clinical activity was observed in previously untreated older AML patients (pts, CR in 4/12); clinical response correlated with gene re-expression (Blum, JCO 2007). The addition of tolerable doses of valproic acid did not appear to improve clinical results or increase gene re-expression compared to decitabine alone. Therefore, we designed a phase II study of single agent decitabine for previously untreated AML pts of age≥60 who were not candidates for intensive chemotherapy (or who refused it). Performance status was ECOG

7075 Background: L is active in myelodysplastic syndromes and myeloma and may also have activity in AL or CLL. Methods: A phase I dose escalation study of L in separate cohorts of relapsed AL or re...

Use of a novel, pharmacokinetically derived schedule of flavopiridol given as a 30 minute (min) intravenous bolus (IVB) followed by 4 hour (hr) infusion (CIVI) resulted in marked improvement in efficacy in refractory chronic lymphocytic leukemia (CLL) compared with earlier studies using other schedules (Byrd, Blood 2007). We modified and intensified the Byrd hybrid IVB/CIVI regimen for single-agent flavopiridol administration in adult acute leukemias to determine the maximum tolerable dose. Using this schedule, 23 patients (pts) have been enrolled in this phase I study of flavopiridol by IVB/CIVI on days 1, 2, and 3. Prophylactic antidiarrheals (loperamide, cholestyramine) were aggressively used. Tumor lysis syndrome (TLS) precautions were utilized in all cases. Dose escalation was as follows (IVB/CIVI dose in mg/m2): 20/30 (n=3), 30/35 (n=7), 30/50 (n=3), 40/60 (n=8), and 50/75 (n=2). Pts had relapsed/refractory AML (n=19) or ALL (n=4) and were 23–78 yrs old (median age 62 yrs). The dose limiting toxicity was secretory diarrhea (Grade 3), occurring in both pts treated at the 50/75 level. Clinically significant diarrhea (

Lenalinomide is an immunomodulatory agent with activity in hematologic malignancies including multiple myeloma and myelodysplastic syndrome. Recent phase II studies have demonstrated that lenalidomide has significant activity in chronic lymphocytic leukemia (CLL). Patients included in this report including a single patient treated off study based on available data for cytoreduction for planned allogeneic stem cell transplantation. Three additional patients with relapsed CLL were enrolled on a IRB approved phase I study evaluating the optimal initial dose in CLL. All patients were treated at 25 mg/day for 21 days with a 7 day off period. Because of previous reports of tumor lysis syndrome and tumor flare during initiation of therapy, patients were initially monitored daily in the outpatient setting with physical examinations and laboratory evaluation. All patients received prophylactic corticosteroids consisting of dexamethasone 12 mg orally days 1–7 followed by 4 mg orally days 7–14 except patient #1, who received prednisone 20 mg daily. Patient specific histories include: Patient #1 had bulky lymphadenopathy and a WBC count of 197,000 at the time of initiation of therapy. On day 3 of therapy he omitted his steroid prophylaxis and rapidly developed a syndrome of worsening lymphocytosis, lymph node enlargement, acute renal failure with laboratory evidence of tumor lysis syndrome, and despite mechanical ventilation died of hypoxemic respiratory failure on day 10 of therapy. Patient #2 initially did well, however on day 25 of course 1 presented to an outside facility with gram negative sepsis in the setting of neutropenia. He recovered fully, however soon after this episode developed disease progression and was taken off study. Patient #3 was asymptomatic until day 8 of course 1, when he developed symptoms of tumor flare during steroid taper with severe abdominal and back pain, skin rash, and low grade fevers. His symptoms resolved with cessation of therapy. He subsequently underwent serial dose reductions but continued to develop signs and symptoms of tumor flare requiring steroid therapy and narcotic pain medication. Patient #4 initiated therapy at 25 mg/day and did well during his steroid taper, however on day 25 while off therapy presented for evaluation of shortness of breath and airway occlusion with recumbency. He was found to have dramatic enlargement of cervical and supraclavicular lymph nodes as well as new tonsillar hypertrophy obstructing his airway; tonsillectomy demonstrated CLL without transformation in the tonsillar tissues. He received steroids with improvement and lenalidomide was discontinued. Lenalidomide administered at 25 mg orally daily is associated with unacceptable toxicity due to myelosuppression, tumor lysis syndrome, and tumor flare. Tumor flare may be indistinguishable from disease progression and may not respond to withdrawal of therapy and steroid administration. Future studies should be designed to initiate therapy at a low dose with gradual dose escalation, with close monitoring for complications. Given the uncertainty of safe dose and schedule of lenalidomide, use of this therapy off an IRB approved study that includes close patient monitoring for tumor flare should not be considered.

Flavopiridol is a cyclin-dependent kinase inhibitor that induces apoptosis in acute leukemia cell lines. In earlier studies with flavopiridol in several malignancies, plasma concentrations of flavopiridol were not reached or maintained at sufficient levels to induce apoptosis due to unexpectedly high levels of bound drug in human serum relative to fetal calf serum used in preclinical studies. PK modeling in chronic lymphocytic leukemia (CLL) cells cultured in human plasma in vitro indicated that administering flavopiridol by 30 minute intravenous (IV) bolus followed by 4 hour continuous IV infusion (CIVI) would achieve sustained in vivo plasma drug concentration and time exposure similar to that necessary to induce apoptosis. We designed a phase I dose escalation trial in acute leukemias of single agent flavopiridol given as a 30 minute bolus followed by a 4 hour CIVI on days 1–3 with the ability to repeat cycles every 21 days; 16 patients (pts) have been enrolled to date. Dose escalation was as follows (bolus dose/4 hr CIVI dose in mg/m2): 20/30 (n=3), 30/35 (n=7), 30/50 (n=3), and 40/60 (n=3). Based on prior experience with flavopiridol at our institution in CLL, aggressive measures for the prevention and management of hyperacute tumor lysis syndrome (TLS) were employed. Pts had relapsed/refractory AML (N=12) and ALL (N=4), and were 25–78 yrs old (median age 64 yrs). Average plasma levels were 1.0–2.5 μM at the first three dose levels during the infusion (N=13) and declined with terminal half-lives comparable to previously reported 72 hr and more recent 4.5 hr infusions. Clinically significant TLS occurred in 2/16 pts with chemical evidence of lysis in 4 additional pts. A dose-limiting toxicity (renal failure) occurred at dose level 4 (40 mg/m2 bolus/60 mg/m2 CIVI), and the level is currently being expanded. Treatment was otherwise well tolerated. Downregulation of Mcl-1 protein by standard immunoblotting at 4 and/or 24 hrs was demonstrated in blood and/or bone marrow cells of 6/10 patients Anti-leukemic activity including transient reductions in WBCs/circulating blasts (n=7), bone marrow blasts (n=2), and platelet transfusion independence (n=1) was observed. Two received a second course of therapy, but no pt experienced an objective response by standard criteria. The current dose level exceeds that previously given in ongoing CLL studies; dose escalation to identify the maximum tolerated dose using this pharmacokinetically derived schedule in acute leukemia continues. Given the activity of this drug as a single agent, combination studies with conventional chemotherapy or other novel agents in acute leukemias should be considered.

6568 Background: Flavopiridol is a cyclin dependent kinase inhibitor with in vitro activity in many cancer cell lines. However, phase I/II studies of either 24 or 72-hour continuous infusion schedules demonstrated no significant clinical activity. Discordant binding of flavopiridol to human plasma proteins as compared to fetal calf serum prompted us to perform pharmacokinetic modeling studies which suggested that optimal dosing would be a 30 min IV bolus followed by 4 hr IV infusion. With this schedule, our group has observed impressive clinical activity in refractory CLL. Methods: We intensified this schedule for relapsed or refractory adult AML and ALL patients (pts) to administer an IV bolus over 30 min followed by an infusion over 4 hrs on 3 consecutive days in a phase I trial. Results: To date, 10 pts have been treated at 2 dose levels. Pts had relapsed/refractory AML (N=6) or ALL (N=4) and were 25–77 yrs old. 4 pts received flavopiridol at 20 mg/m2 IV bolus and 30 mg/m2 infusion; 6 received 30 mg/m2 bolus followed by 35 mg/m2 infusion. The most significant toxicity was tumor lysis; treatment was well tolerated, and toxicities were similar to those previously reported by our group with the single day dosing schedule used in CLL. Plasma levels were 1–2 μM during the infusion (N=7) and declined with a terminal half life comparable to that previously reported with a 72 hr infusion. Significant anti-leukemic activity was seen in 5/7 evaluable pts at both dose levels. Tumor lysis was seen in both ALL and AML (see table ). Downregulation of Mcl-1 protein by immunoblotting was seen in 2/3 pts tested to date. Conclusions: Single agent flavopiridol given with this novel, pharmacologically modeled schedule has clinical activity in pts with relapsed/refractory ALL and AML. Further study in acute leukemia using this schedule is warranted; dose escalation to the current trial is ongoing. (NCI U01 CA 76576–05) [Table: see text] No significant financial relationships to disclose.

6515 Background: Decitabine, an inhibitor of DNA methyltransferase (DNMT) enzymes, has activity in myeloid malignancies at doses >1 log below the MTD of 2250mg/m2/course which may be optimal for DNA demethylation and minimize cytotoxicity. Methods: We designed a two step trial for AML patients (pts) to determine: Step 1, the lowest dose of decitabine to induce 100% increase in or re-expression of epigenetically silenced genes in 5/6 pts treated at a dose level; and Step 2, the MTD of the histone deacetylase (HDAC) inhibitor VA given with this dose of decitabine, and whether this MTD or a lower dose leads to 90% decrease in HDAC activity. Results: Decitabine was administered to 17 pts at two dose levels. Pts had relapsed/refractory AML (N=10) or age>60 and ineligible/refused standard therapy (N=7) and ranged in age from 36–83 years. Pts received decitabine at 15–20mg/m2/IV over 1 hr daily for 10 days (d) (3 pts also had VA 15mg/kg on days 5–21), every 28 d. Mean plasma decitabine Cmax (by a validated LC-MS/MS method) was 93 ng/ml (N=7). 10/13 pts had at least 100% increase in expression of p15 or estrogen receptor (ER, including 5/6 given 20mg/m2/d decitabine alone), and all 10 had clinical response. Of the 3 pts who did not have increased gene expression none responded. Western blotting showed depletion of DNMT protein in 4/6 pts. Bisulfite sequencing of the promoter region of ER confirmed that decitabine induced >50% decrease in methylation in the only pt yet examined (p100K, 2 had stabilization of disease for 4–6 months. Conclusions: We demonstrated clinical activity of low dose decitabine associated with decreased levels of the DNMT1 target and increased or re-expression of epigenetically silenced genes. Combination of decitabine at 20mg/m2/d with VA (Step 2) has begun; complete clinical results, gene re-expression/ demethylation, and histone deacetylation data will be presented. (NCI U01 CA 76576–05) [Table: see text]

GTI-2040 is a 20-mer antisense to the R2 component of RNR mRNA. RNR is required for the conversion of ribonucleotides to deoxyribonucleotides, a crucial step during DNA synthesis and repair. Cytarabine (AraC) is a cytotoxic agent that is converted into AraC triphosphate (Ara-CTP) and is the backbone of several regimens in AML. Ara-CTP competes with deoxycytidine for DNA incorporation. We hypothesize that RNR downregulation by GTI-2040 results in decrease of levels of deoxycytidine thereby leading to a preferential DNA incorporation of ARA-CTP and increase in its cytotoxic activity. To test this hypothesis we undertook a CTEP-sponsored Phase I dose-escalation study of GTI-2040 plus HiDAC in patients (pts) with relapsed or refractory AML. Pts were stratified in 2 cohorts according to age. Cohort I (18–59 yrs) received escalating doses of GTI-2040 (dose level 1: 3.5 mg/m2/d) by continuous IV infusion (CIVI) on d 1–6 combined with escalating doses of cytarabine IV over 2 hrs q12 hrs on d 2, 4, and 6 (dose level 1: 2500 mg/m2/dose). Cohort II (≥60 yrs) received GTI CIVI on d 1–6 and cytarabine IV over 4 hrs on d 2 to 6 (dose level 1: 1500 mg/m2/d). To date, 30 pts were enrolled. Pts received median of 1 prior regimen (range 1–3). Cohort I included 8 pts with relapsed and 6 with refractory disease; 7 had intermediate risk cytogenetics (CyG) and 7 adverse CyG; 6 received prior HiDAC. Cohort II included 10 pts with relapsed and 6 with refractory disease; 8 pts had intermediate risk CyG and 8 high risk CyG; 5 pts received prior HiDAC. Toxicities were comparable to HiDAC therapy alone. Grade 3/4 non-hematologic toxicities included fatigue, fevers, anorexia, pneumonitis, and catheter related infections; a grade 3 reversible cerebellar toxicity (n=1) was observed at level 1/cohort I. An ELISA-based assay with a limit of quantification of 50 pMol was used to determine GTI2040 plasma and intracellular (IC) concentrations. Dose-dependent increase in plasma steady state concentration (Css) and area under the curve (AUC) of GTI2040 was observed in both cohorts, although higher AUC and longer t1/2 were demonstrated in the younger pts compared to the older ones. In cohort I, disease responses were seen at all dose levels Five of 14 pts achieved complete remission (CR) and one achieve incomplete CR (CRi; i.e., no marrow disease and incomplete blood count recovery). In cohort II, no disease response was observed. Median IC GTI2040 concentration in BM mononuclear cells at 120 hours following start of antisense infusion was higher in younger (i.e., 175 nM) than in older (i.e., 75 nM) pts. A median decrease in R2 protein levels of 50% (range 50–90%) detected by immunoblotting was noted in 5/9 and 5/10 pts in cohort I and II, respectively. In cohort I CR pts (n=4) had a median 50% decrease and non-responders (n=9) had a median 200% increase in R2 levels. In cohort II changes in R2 levels did not predict disease response. In summary, combination of GTI-2040/HiDAC is feasible. PK/PD studies demonstrate achievable plasma and IC levels of the antisense and target downregulation. Disease response was observed only with the dose/schedule administered to younger pts. Dose escalation in this group continues to establish a recommended dose for Phase II trials. [NCI U01 CA 76576-05].

We report here for the first time a case of “decitabine-induced differentiation syndrome” in a patient (pt) with acute myeloid leukemia (AML). The cytosine analog decitabine, after incorporating into DNA, irreversibly binds DNA methyltransferase (DNMT) enzymes where cytosine residues are targeted for methylation. This allows replication of unmethylated DNA with subsequent re-expression of genes previously silenced by promoter methylation. It has been suggested that decitabine at low doses may have differentiating effects, as compared to cytotoxic effects at higher doses. A previous phase I trial demonstrated clinical activity of low dose decitabine in patients with myeloid malignancies (Issa, et al., Blood 2004). Given the close relationship of DNA methylation and histone deacetylation in modulating gene expression, we are currently conducting a phase I trial (OSU 0336) of low dose decitabine (15mg/m2 IV over 1 hour on days 1–10) alone (step 1) or in combination with escalating doses of the histone deacetylase inhibitor valproic acid (step 2) in AML. An 82 year old male pt with untreated, secondary AML (65% bone marrow blasts, 95% marrow cellularity) was enrolled on step 1 of the study and given 15mg/m2/day of decitabine for 10 consecutive days. At the time of initiation of therapy, the pt had a white blood cell (WBC) count of 8,700/uL with absolute neutrophil count (ANC) of 1,500/uL and absolute blast count (ABC) of 3,200/uL. At day 11, the pt had WBC 1,000/uL with ANC of 450/uL and ABC of 150/uL and was clinically well. However, at day 17, he presented with cough and shortness of breath, without fever. WBC had risen to 18,700/uL with ANC of 11,000/uL and ABC of 750/uL. The patient developed worsening hypoxia and required mechanical ventilation. Chest radiograph demonstrated diffuse interstitial infiltrates, but bronchoscopy and lavage (on day 18 and repeated on day 24) did not identify an infectious etiology. Due to clinical concern for a differentiation syndrome similar to the “retinoic acid syndrome” occurring in acute promyelocytic leukemia patients treated with all-trans-retinoic-acid (ATRA), the pt was started on dexamethasone 10mg IV q12 hours beginning on day 18, in addition to broad spectrum antimicrobial coverage. Peripheral blood smears during the following week showed evidence of myeloid differentiation, and by day 25 no circulating blasts were found (WBC 4,300/uL, ANC 3,000/uL) while the overall clinical condition improved. The pt was finally extubated on day 38 but within 24 hours required emergent re-intubation due to nasogastric feeding aspiration and died at day 53. In summary, these preliminary data support the biological activity of low dose decitabine in AML and suggest that clinical precautions similar to those implemented for the “retinoic acid syndrome” in ATRA-treated APL should be considered in decitabine-treated AML when myeloid differentiation and rising neutrophil counts are observed.

Adequate dosing of lenalidomide in Chronic Lymphocytic Leukemia (CLL) remains unclear. This study determined maximum tolerated dose (MTD) in relapsed CLL patients (Cohort A) and patients achieving a partial response (PR) or better to recent therapy (Cohort B). Thirty-seven patients were enrolled. MTD was 2.5 mg followed by 5.0 mg continuous. In Cohort A, tumor flare grade 1–2 occurred in 15 patients (50%) and grade 3 in 1 patient (3%). Cohort A had 19 of 23 evaluable (83%) patients, 4 PR (17%) and 15 (65%) stable disease (SD), Cohort B had 6 of 7 patients (86%) with SD. Despite overall response rate not being high, many patients remained on therapy several months with SD.