Sullivan, Daniel M.

8013 Background: Obatoclax mesylate (GX15-070MS) is a BH3 mimetic that inhibits Bcl-2 protein family members including MCL-1, a dominant target in myeloma (MM). Obatoclax (OBX) inhibited viability of 14 MM cell lines (mean IC50 215 nM) and primary MM samples while exhibiting pre clinical synergy with bortezomib (BTZ). Sensitivity correlated with basal levels of Mcl-1 and Bcl-XL, but not Bcl2, Bim, Bax or Bak expression. Methods: We report a phase I trial of OBX in combination with BTZ. Eligibility required measureable disease, > 1 prior MM therapy, ≤10 cycles of prior BTZ and did not progress on prior BTZ therapy, creatinine ≤2 ULN. Starting dose level 1 was OBX 14 mg/m2 24-hour continuous iv. infusion days 1, 8, 15 of a 21-day cycle. BTZ given at 1.3mg/m2 iv. days 1, 4, 8 and 11. After protocol amendment OBX level 1 dosing was 30 mg/m2, level 2 was 40 mg/m2 IV both by continuous 3 hour infusion days 1, 8 and 15 on a 21 day schedule. Pre med. with famotidine was required. Results: Eleven patients were accrued, median age 62 (range: 46-77), median time from diagnosis was 4.7 years. Median of 2.5 cycles (range: 1-10). Median follow-up for patients still alive is 11.6 months (range: 0.9-35.5). At dose level 1, there were 2 DLTs. After amendment 8 patients were accrued (3 hour infusion): 4 at amended dose level 1 and 4 at dose level 2. All patients are now off treatment. 10 patients are evaluable for response: 2 patients at original dose level 1 (2 PR), 3 patients at dose level 1 (2 PR, 1 MR), no patients at dose level 2 responded: overall PR of 40%, clinical benefit response in 50% (95% CI: 19-81%). 6 patients had disease progression and 2 patients died. 4 DLTs were seen: at original dose level 1 grade 4 thrombocytopenia and delay of therapy > 15 days. At dose level 2, 1 patient had grade 3 somnolence, a 2nd patient grade 3 euphoria and grade 4 thrombocytopenia. No DLTs were seen at amended dose level 1. Common adverse events of any grade included GI, hematologic and neurologic e.g. euphoria, decreased level of consciousness, psychosis, speech. Conclusions: In summary MTD is OBX 30mg/m2 by 3 hour iv infusion once weekly, BTZ 1.3 mg/m2 days 1,4,8, and 11. Major toxicities were central neurologic and hematologic. This P2C consortium study was supported by NCI N01-CM62205.

5020 Background: V+C was well tolerated in a phase I trial and responses and prolonged disease stabilization were observed in BRCA + patients (pts).To assess the relative contribution of the PARP inhibitor to the efficacy observed for the combination, we conducted a randomized multicenter trial comparing the response rate (RR) of V and C to the RR of C alone in patients with deleterious BRCA mutations and recurrent ovarian, or primary peritoneal, fallopian tube or high-grade serous ovarian cancer. Methods: Pts were ≥ 18 yrs, KPS ≥ 70%, had adequate organ function, prior therapy with PARP inhibitors was allowed.Both drugs were administered orally qd; C 50 mg, V 60 mg; 21 day cycles. Pts were randomized to receive either C alone or V+C. At disease progression, pts on C alone were allowed to cross over to the combination. Radiologic imaging was performed at baseline and q 3 cycles for assessment of response. Dose reduction of V was allowed to 40 mg for gr 3 non-hematologic or gr 4 hematologic toxicities. The study design had an 88% power to detect the difference between a 15% RR for C alone versus 35% for V+C, early closure if fewer responses were observed on the combination arm in the first 65 pts enrolled (half of the total projected accrual). Results: Total of 74 pts were enrolled (36 pts C, 38 pts V+C), median age 58 (37-79 yrs), # of prior therapies: median 4 (1-9), 2 pts had prior PARP therapy. Treatment was well tolerated, Gr ≥ 2 toxicities per arm for initial regimen (# of pts): C alone: lymphopenia (2), mucositis (1); V+C: lymphopenia (4), anemia (2), leucopenia (2), neutropenia (2). Of the 74 pts evaluable for response at the interim analysis, 3 PRs observed in 36 pts on V+C and 5 PRs of 38 pts on C alone arm; thus accrual was stopped. PAR levels assessed by validated ELISA were inhibited (>80%) in PBMCs in 9/10 pts 4 hours post V, no inhibition with C alone. Conclusions: Addition of V, a PARP inhibitor, to C did not improve RR versus C alone. Exomic sequencing, gene expression studies, and Fanconi Anemia triple stain immunofluorescence (FATSI) assay for FancD2 nuclear foci formation using archival tissue are ongoing.

5517 Background: Anti-angiogenic therapy is active in OC; the combination of VEGF and mTOR inhibitors is hypothesized to further improve activity. This report is the OC cohort of a multi-histology phase II study assessing the activity and toxicity of B/T. Methods: Patients (Pts) with recurrent epithelial OC who had received ≤ 2 chemotherapy regimens and no prior treatment with a VEGF or mTOR inhibitor were eligible. A two-stage design was used with second stage accrual if >6 pts had objective responses (OR) or >10 pts of the first 25 remained progression-free (PF) at six months (mo). Pre-defined end-points for a recommendation for further clinical trial evaluation included at least 15/50 with OR or 26/50 PF at six mo. Treatment included T 25 mg IV wkly and B 10 mg/kg IV q14 days on 28 day cycles. Results: 58 pts were enrolled (the first 50 pts are used to determine a final recommendation). Median age=62 (range 35-82). A median of 4 (range 1-23) cycles were administered. 24 were platinum-sensitive, 34 resistant. Off-study reasons included 13 adverse events and disease progression in 38. 3 refused further therapy due to toxicity. 14 of the first 50 pts had partial response (PR) (9 platinum-resistant); 25/50 remained PF (8 PR, 15 SD, 2 non-progressing) at 6 mo. Grade (gr) 3/4 toxicities occurring >2 events include: fatigue (4), stomatitis (7), hypertension (5), neutropenia (4), thrombocytopenia (4), hypokalemia (3). One rectal and one vaginal fistula, and two colonic perforations (one gr 2 and one gr 3 during cycles 3 and 1 respectively) were observed. Episodes of gr 1/2 oral, nasal, pulmonary, vaginal and gastrointestinal hemorrhage were also observed. Conclusions: Although the OR and PFS did not reach pre-defined standards, the numbers of OR and 6 mo PFS suggest potential enhanced activity with a combination of mTOR inhibitor with anti-angiogenic therapy. Other combinations of these targeted agents may result in more satisfactory activity with less toxicity. N01-CM-62203 (PMH) N01-CM-62208 (Southeast Phase 2) N01 CM-62209 (CCCP) N01-CM-62204 (NYCC) N01-CM-2011-0071C (Chicago) N01-CM62205 (Mayo) Clinical trial information: NCT01010126.

Abstract Lessons Learned Targeted therapy options for SCLC patients are limited; no agent, thus far, has resulted in a strategy promising enough to progress to phase III trials. Linsitinib, a potent insulin growth factor-1-receptor tyrosine kinase inhibitor, may be one agent with activity against SCLC. Despite lack of a reliable predictive biomarker in this disease, which may have partly contributed to the negative outcome reported here, linsitinib, although safe, showed no clinical activity in unselected, relapsed SCLC patients. Background. Treatment of relapsed small-cell lung cancer (SCLC) remains suboptimal. Insulin growth factor-1 receptor (IGF-1R) signaling plays a role in growth, survival, and chemoresistance in SCLC. Linsitinib is a potent IGF-1R tyrosine kinase inhibitor that potentially may be active against SCLC. Methods. In this phase II study, 8 eligible patients were randomly assigned in a 1:2 ratio to topotecan (1.5 mg/m2 intravenously or 2.3 mg/m2 orally, daily for 5 days for 4 cycles) or linsitinib (150 mg orally twice daily until progression). The primary endpoint was progression-free survival. Patients with relapsed SCLC, platinum sensitive or resistant, performance status (PS) 0–2, and adequate hematologic, renal, and hepatic function were enrolled. Patients with diabetes, cirrhosis, and those taking insulinotropic agents were excluded. Crossover to linsitinib was allowed at progression. Results. Fifteen patients received topotecan (8 resistant, 3 with PS 2) and 29 received linsitinib (16 resistant, 5 with PS 2). Two partial responses were observed with topotecan. Only 4 of 15 patients with topotecan and 1 of 29 with linsitinib achieved stable disease. Median progression-free survival was 3.0 (95% confidence interval [CI], 1.5–3.6) and 1.2 (95% CI, 1.1–1.4) months for topotecan and linsitinib, respectively (p = .0001). Median survival was 5.3 (95% CI, 2.2–7.6) and 3.4 (95% CI, 1.8–5.6) months for topotecan and linsitinib, respectively (p = .71). Grade 3/4 adverse events (>5% incidence) included anemia, thrombocytopenia, neutropenia/leukopenia, diarrhea, fatigue, dehydration, and hypokalemia for topotecan; and thrombocytopenia, fatigue, and alanine aminotransferase/aspartate aminotransferase elevations for linsitinib. Conclusion. Linsitinib was safe but showed no clinical activity in unselected, relapsed SCLC patients.