Ruckdeschel, John C.

7029 Background: CBP501, a synthetic duodecapeptide, enhances the cytotoxicity of cisplatin in cell lines and xenografts, including NCI-H226 human mesothelioma. CBP501 increases cisplatin influx into tumor cells through an interaction with calmodulin, and inhibits cell cycle progression by abrogating DNA repair at the G2 checkpoint. Phase I clinical trials combining CBP501 with cisplatin alone or with pemetrexed showed acceptable safety profiles and suggested activity. The most common toxicity of CBP501 is infusion-related urticaria, which is easily managed with diphenhydramine. Methods: Chemotherapy-naive patients with unresectable MPM were stratified by histology (epithelioid vs other) and performance status (PS 0-1 vs 2) and randomized 2:1 to Arm A: pemetrexed/cisplatin plus CBP501 25 mg/m2 IV (42 pts planned), or Arm B: pemetrexed/cisplatin alone at standard doses (21 pts planned). Patients continued on treatment until progression or intolerance; no maintenance therapy was delivered. The primary endpoint is progression free survival (PFS) in Arm A; if > 23 of the 42 patients remain free of progression more than 4 months, the combination will be deemed worthy of further study. In addition to standard CT imaging to assess response and PFS, PET scans, pulmonary function tests, and mesothelin levels were performed. Results: Enrollment was completed in October 2011. 65 pts from 14 institutions were randomized, and 63 were treated. Patient characteristics in the two arms were similar and as follows: median age 65, 82% male, 71% epithelioid histology, 8% PS2. Grade 3/4 treatment-related toxicities were uncommon, no different than expected from standard chemotherapy, and comparable in the two arms. 70% of patients treated with CBP501 had infusion reactions, all grade 1-2. The best overall response rate in evaluable patients (modified RECIST, investigator assessed) was 12/37 (32%) (95% CI 18-50) in Arm A, and 3/22 (14%) (95% CI 3-35) in Arm B. The median number of chemotherapy cycles was 5.5 in Arm A, 5 in Arm B. Conclusions: Data on the primary endpoint of PFS in Arm A are maturing and will be presented at the meeting.

CRA7004 Background: Selenium was reported to have possible lung cancer chemopreventive benefits based on a large skin cancer trial secondary observation. (JAMA 1996; 276: 1957-1963). Since that time, research continued to suggest that Se could decrease risk of second primary tumor (SPT) in persons with resected NSCLC. In 2007, a publication from another group suggested an increased association of Se with type 2 diabetes (Annals Int Med 147:217-223). Methods: From Oct 2000-Nov 2009, 6 groups, led by ECOG, carried out a double blind, placebo controlled trial using selenized yeast 200 micrograms daily in a 2:1 randomization vs. placebo for 48 mo in completely resected stage I NSCLC. Participation was 6–36 mo post-op and required a negative mediastinal node biopsy, no excessive vitamin intake, normal liver function, a negative chest x-ray, and no other evidence of recurrence. Planned size of 1,960 participants had been designed to detect a 40% decrease in SPTs with 80% power. Methylation studies of sputum and blood (S. Belinsky) add important biologic correlates to this project. Results: Interim analysis occurred in Oct 2009 after 1,561/1,772 pts reached step 2 (completion of the 4 week (step 1) run-in period requiring at least 75% of the study drug to be taken). Endpoints included SPTs, recurrence, and toxicity. A total of 216 SPTs developed of which 84 (38.9%) were lung cancer. SPT (lung/overall) incidence was 1.36/3.66 per 100 person yrs for placebo vs. 1.91/4.11 for Se (p=.150). 5 yr progression free survival was 78% for placebo vs. 72% for Se. Study was stopped according to futility analysis. Grade 1 or 2 toxicity occurred in 38% of placebo and 39% Se. Grade 3 toxicity was 3% placebo vs. <1% Se. Compliance was excellent (>95% at 2 yrs). Conclusions: No increase in diabetes mellitus or skin cancer was detected. Se was safe but conferred no benefit over placebo. Methylation studies are continuing. [Table: see text]