Updated 5-y landmark analyses of phase 2 (BREAK-2) and phase 3 (BREAK-3) studies evaluating dabrafenib monotherapy in patients with BRAF V600–mutant melanoma.

Authors

null

Paul B. Chapman

Memorial Sloan Kettering Cancer Center, New York, NY

Paul B. Chapman , Paolo Antonio Ascierto , Dirk Schadendorf , Jean Jacques Grob , Antoni Ribas , Felix Kiecker , Caroline Dutriaux , Lev V. Demidov , Celeste Lebbe , Piotr Rutkowski , Christian U. Blank , Ralf Gutzmer , Michael Millward , Richard Kefford , Yingjie Huang , Ying Zhang , Matthew Squires , Bijoyesh Mookerjee , Axel Hauschild

Organizations

Memorial Sloan Kettering Cancer Center, New York, NY, Istituto Nazionale Tumori “Fondazione G.Pascale”- IRCCS, Naples, Italy, University Hospital of Essen, Essen, Germany, Aix-Marseille University, Marseille, France, University of California Los Angeles Jonsson Comprehensive Cancer Center, Los Angeles, CA, Charité Universitätsmedizin Berlin, Berlin, Germany, Hôpital Saint André, CHU de Bordeaux, Bordeaux, France, N. N. Blokhin Cancer Research Center, Russian Academy of Medical Sciences, Moscow, Russia, University Paris Diderot, Paris, France, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw, Poland, The Netherlands Cancer Institute (NKI), Amsterdam, Netherlands, Hannover Medical School, Hannover, Germany, University of Western Australia, Sir Charles Gairdner Hospital, Perth, Australia, Westmead Hospital and Macquarie University, Sydney, Australia, Novartis Pharmaceuticals Corporation, East Hanover, NJ, Novartis Pharmaceuticals AG, Basel, Switzerland, Schleswig-Holstein University Hospital, Kiel, Germany

Research Funding

Pharmaceutical/Biotech Company

Background: Prior analyses of phase 2 (BREAK-2; NCT01153763) and phase 3 (BREAK-3; NCT01227889) trials showed that durable clinical benefit and tolerability lasting ≥ 3 y are achievable with the BRAF inhibitor dabrafenib in some patients (pts) with BRAFV600–mutant metastatic melanoma. Here, we report 5-y landmark analyses for BREAK-2 and BREAK-3. Methods: BREAK-2, a single-arm, phase 2 study, evaluated dabrafenib 150 mg twice daily in pts with stage IV BRAF V600E/K–mutant MM. BREAK-3, an open-label, randomized (3:1), phase 3 study, assessed dabrafenib 150 mg twice daily vs dacarbazine 1000 mg/m2 every 3 weeks in pts with previously untreated BRAFV600E–mutant unresectable stage III or stage IV MM. Updated analyses were performed to describe ≥ 5-y outcomes in each study. Results: BREAK-2 enrolled 92 pts (V600E, n = 76; V600K, n = 16), of whom most (90%) had prior systemic anticancer therapy. At data cutoff (17 Jun 2016), all pts had discontinued, mostly due to progression (84%). In V600E pts, 5-y progression-free survival (PFS) was 11%, and 5-y overall survival (OS) was 20%. Postprogression immunotherapy was received by 22% of enrolled pts. In BREAK-3 (data cutoff, 16 Sep 2016), median follow-up was 18.6 mo for the dabrafenib arm (n = 187) and 12.8 mo for the dacarbazine arm (n = 63). Follow-up for the 37 dacarbazine-arm pts (59%) who crossed over to receive dabrafenib was based on the initial assignment of dacarbazine. The 5-y PFS was 12% vs 3% and 5-y OS was 24% vs 22% for the dabrafenib and dacarbazine arms, respectively. A subset of pts in each respective arm received postprogression anti–CTLA-4 (24% vs 24%) and/or anti–PD-1 (8% vs 2%) therapy, whereas 31% vs 17% did not receive any further therapy following study treatment. No new safety signals were observed in either study with long-term follow-up. Additional characterization of pts using cfDNA analysis will be presented. Conclusions: These data provide the longest reported PFS and OS follow-up for BRAF inhibitor monotherapy in BRAF V600–mutant MM. Both BREAK-2 and BREAK-3 showed that 11%-12% of pts initially treated with single-agent dabrafenib remained progression free at 5 y. Clinical trial information: NCT01153763; NCT01227889

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Abstract Details

Meeting

2017 ASCO Annual Meeting

Session Type

Poster Session

Session Title

Melanoma/Skin Cancers

Track

Melanoma/Skin Cancers

Sub Track

Advanced/Metastatic Disease

Clinical Trial Registration Number

NCT01153763; NCT01227889

Citation

J Clin Oncol 35, 2017 (suppl; abstr 9526)

DOI

10.1200/JCO.2017.35.15_suppl.9526

Abstract #

9526

Poster Bd #

134

Abstract Disclosures