Chapman, Paul B.

CRA9003 The full, final text of this abstract will be available at abstract.asco.org at 7:30 AM (EDT) on Saturday, June, 1, 2013, and in the Annual Meeting Proceedings online supplement to the June 20, 2013, issue of Journal of Clinical Oncology. Onsite at the Meeting, this abstract will be printed in the Saturday edition of ASCO Daily News.

CRA9003 Background: Gq/11 mutations are early oncogenic events in UM resulting in MAPK pathway activation. We demonstrated decreased viability in UM cell lines harboring Gq/11 mut with sel, a small molecule inhibitor of MEK1/2 (Ambrosini, CCR 2012). Methods: We conducted a 16 center randomized phase II study of hyd-sulfate sel 75 mg BID vs TMZ 150 mg/m2 daily for 5 days in 28-day cycles (or DTIC 1000 mg/m2 q21 days) for patients (pts) with metastatic UM with a Q209 Gq/11 mut who have not received prior TMZ/DTIC. The primary endpoint was progression free survival (PFS). Secondary endpoints included overall survival (OS) and response rate (RR). Select pts underwent tumor biopsies at baseline and after 14 (+/- 3 days) of sel. Our statistical plan required ≥80 pts randomized and ≥68 events to detect a PFS hazard ratio of 0.6 (p=0.1). Randomization was stratified by mut (Gq vs G11), M stage and number of prior therapies (tx). Tumor assessment occurred every 4 weeks (wks) for 8 wks and then every 8 wks using RECIST 1.1. Pts receiving TMZ who progressed could receive sel (TMZ→sel). Results: 80 pts were randomized. Sel (n=39): median age 66 (range 32-86), 54% male, 54% G11 mut, median ECOG PS 0 (range 0-1), 97% M1c, median prior tx 0 (range 0-2). TMZ (n=41): median age 60 (range 34-81), 63% male, 58% G11 mut, median ECOG PS 0 (range 0-1), 93% M1c, median prior tx 0 (range 0-2). 11/39 (28%) pts on sel experienced grade (gr) 3 toxicity (tox) manageable with dose modification (5 CPK elevation, 3 LFT elevation, 1 rash, 1 lymphopenia, 1 edema). 1/41 (2%) pt on TMZ experienced gr 3 tox (neutropenia). No gr 4/5 tox occurred. 28 pts on sel underwent paired tumor biopsies with inhibition of pERK and cyclinD1 observed by Western blot at day 14. At interim analysis (9/25/12), 55 pts were evaluable with 45 progression events and 16 deaths. Sel (n=27): median PFS 16 wks (95% CI 8-30.9), RR 11%, median OS 11.8 months (95% CI 4.8-not reached). TMZ (n=28): median PFS 4 wks (95% CI 3.7-15), RR 0%, median OS 4.7 months (95% CI 4.3-14.3). TMZ→sel (n=25): median PFS 8.1 wks (95% CI 7-15), RR 0%. Conclusions: Sel is the first drug to ever show improved clinical activity in UM relative to TMZ. Sustained target inhibition is observed with sel. Final results will be presented. Clinical trial information: NCT01143402.

Abstract Targeted therapies and immunotherapies have led to significant improvements in the treatment of advanced cancers, including metastatic melanoma. However, new strategies are desperately needed to overcome therapeutic resistance to these agents, as well as to identify effective treatment approaches for cancer patients that fall outside major targetable mutational subtypes (e.g., non–V600 BRAF melanoma). One such strategy is to extend the paradigm of individually tailored, molecularly targeted therapy into a broader spectrum of melanoma patients, particularly those bearing tumors without commonly recognized therapeutic targets, as well as having failed or were ineligible for immunotherapy. In this nontreatment pilot study, next-generation sequencing (NGS) technologies were utilized, including whole genome and whole transcriptome sequencing, to identify molecular aberrations in patients with non–V600 BRAF metastatic melanoma. This information was then rationally matched to an appropriate clinical treatment from a defined pharmacopeia. Five patients with advanced non–V600 BRAF metastatic melanoma were enrolled. We demonstrated successful performance of the following during a clinically relevant time period: patient tumor biopsy, quality DNA/RNA extraction, DNA/RNA-based sequencing for gene expression analysis, analysis utilizing a series of data integration methodologies, report generation, and tumor board review with formulated treatment plan. Streamlining measures were conducted based on the experiences of enrolling, collecting specimens, and analyzing the molecular signatures of patients. We demonstrated the feasibility of using NGS to identify molecular aberrations and generate an individualized treatment plan in this patient population. A randomized treatment study utilizing lessons learned from the conduct of this pilot study is currently underway. Mol Cancer Ther; 14(8); 1962–71. ©2015 AACR.