Poster Presentation Clinical Oncology Society of Australia Annual Scientific Meeting 2018

Two-year efficacy and safety update from JAVELIN Merkel 200 part A: a registrational study of avelumab in metastatic Merkel cell carcinoma (mMCC) progressed on chemotherapy (#364)

Tom van Hagen 1 , Shahneen Sandhu 2 , Paul Nghiem 3 , Shailender Bhatia 4 , Andrew S. Brohl 5 , Omid Hamid 6 , Janice M. Mehnert 7 , Patrick Terheyden 8 , Kent C. Shih 9 , Isaac Brownell 10 , Celeste Lebbe 11 , Karl D. Lewis 12 , Gerald P. Linette 13 , Michele Milella 14 , Meliessa Hennessy 15 , Marcis Bajars 15 , Christine Hicking 16 , Sandra P. D'Angelo 17
  1. St. John of God Hospital, Subiaco, WA, Australia
  2. Oncology, Peter MacCallum Cancer Centre, Victorian Comprehensive Cancer Centre, Melbourne, VIC, Australia
  3. Dermatology, University of Washington Medical Center at South Lake Union, Seattle, WA, USA
  4. Medical Oncology, University of Washington Medical Center, Seattle, WA, USA
  5. Medical Oncology, Moffitt Cancer Center, Tampa, FL, USA
  6. Translational Research and Immunotherapy, Melanoma Therapeutics, The Angeles Clinic and Research Institute, Los Angeles, CA, USA
  7. Medical Oncology, Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA
  8. Dermatology, Allergology, and Venereology, University of Lübeck, Lübeck, Germany
  9. Medical Oncology, Sarah Cannon Research Institute/Tennessee Oncology, Nashville, TN, USA
  10. Cutaneous Development and Carcinogenesis, National Cancer Institute, Bethesda, MD, USA
  11. CIC and Dermatology, Saint Louis Hospital, Paris, France
  12. Division of Medical Oncology, University of Colorado Denver, School of Medicine, Aurora, CO, USA
  13. Center for Cellular Immunotherapies, University of Pennsylvania, Philadelphia, PA, USA
  14. IRCCS Regina Elena National Cancer Institute, Rome, Italy
  15. Global Clinical Development, Immuno-Oncology, EMD Serono, Billerica, MA, USA
  16. Biostatistics, Merck KGaA, Darmstadt, Germany
  17. Medical Oncology, Memorial Sloan Kettering Cancer Center & Weill Cornell Medical College, New York, NY, USA

Aims: We report efficacy and safety data from part A of the single-arm, phase 2, JAVELIN Merkel 200 trial of avelumab—anti–PD-L1 monoclonal antibody؅—in patients (pts) with mMCC and ≥2 y of follow-up.

 Methods: Pts with mMCC and progressive disease (PD) on prior chemotherapy received avelumab 10 mg/kg IV Q2W until PD or intolerable adverse event (AE). Objective response rate (ORR), duration of response (DOR), and progression-free survival (PFS) were evaluated by independent review per RECIST v1.1; overall survival (OS) and AEs (per NCI CTCAE v4.0) were also evaluated.

 Results: As of 26 Sep 2017, 88 pts were followed for a median of 29.2 mo (range 24.8-38.1). Median duration of treatment was 3.9 mo (range 0.5-36.3); treatment was ongoing in 10.2% of pts. The confirmed ORR of 33.0% (95% CI 23.3-43.8; complete response in 11.4%) remained unchanged from analyses at 1 y and 18 mo; responses were ongoing in 19 of 29 pts (12 pts with >2 y response duration). Median DOR had not been reached (range 2.8-31.8 mo; 95% CI 18.0-not estimable). Durable responses led to stable PFS rates (1-y: 29%; 18-mo: 29%; 2-y: 26%). Median OS was 12.6 mo (95% CI 7.5-17.1); 2-y OS rate was 36% (1-y: 50%; 18-mo: 39%). Clinical activity was observed across all pt subgroups. The AE profile remained consistent with previous analyses: 76.1% had a treatment-related AE (TRAE; grade ≥3 in 11.4%), 22.7% had an immune-related AE, and no treatment-related deaths occurred.

 Conclusion: At ≥2 y of follow-up, avelumab shows continued durable responses, meaningful survival outcomes, and a manageable safety profile in pts with mMCC.

 Results were presented in part at the 2018 ASCO Annual Meeting and published in the conference proceedings as abstract 9507. © 2018 American Society of Clinical Oncology, Inc. Reused with permission.