Best Of Best Poster Oral Clinical Oncology Society of Australia Annual Scientific Meeting 2018

Avelumab treatment of Australian patients with metastatic Merkel cell carcinoma (mMCC): experience from an expanded access program (EAP) (#365)

Tom van Hagen 1 , Shahneen Sandhu 2 , Vijay Kasturi 3 , Christopher Steer 4 , Chloe Khoo 2 , Ina Nordman 5 , Meliessa Hennessy 6 , Steven Hildemann 7 , Josh Reed 8 , Subramanian Hariharan 9
  1. St. John of God Hospital, Subiaco, WA, Australia
  2. Oncology, Peter MacCallum Cancer Centre, Victorian Comprehensive Cancer Centre, Melbourne, VIC, Australia
  3. Medical Affairs, EMD Serono, Billerica, MA, USA
  4. Medical Oncology, Albury Wondonga Regional Cancer Centre, Albury, NSW, Australia
  5. Department of Medical Oncology, Calvary Mater Newcastle, Waratah, NSW, Australia
  6. Global Clinical Development, Immuno-Oncology, EMD Serono, Billerica, MA, USA
  7. Global Patient Safety, Merck KGaA, Darmstadt, Germany
  8. Global Early Access - avelumab, EMD Serono, Billerica, MA, USA
  9. Medical Affairs, Pfizer, Inc., New York, NY, USA

Aims: Avelumab—a human anti–PD-L1 IgG1 monoclonal antibody—showed clinical activity and a manageable safety profile in the phase 2 JAVELIN Merkel 200 trial (NCT02155647), leading to its approval in multiple countries. Here, we describe real-world experience with avelumab in Australian patients with mMCC.

 Methods: Patients participating in the EAP (NCT03089658) had stage IV mMCC and PD on/after chemotherapy or were ineligible for chemotherapy or participation in clinical trials. In contrast to JAVELIN Merkel 200, with medical approval, patients could have ECOG ≥2, treated brain metastases, or immunosuppressive conditions. Patients received avelumab 10 mg/kg IV Q2W until PD or unacceptable toxicity. A 3-mo supply was provided; resupply was allowed for patients with complete response (CR), partial response (PR), stable disease, or clinical benefit per physician assessment. No central imaging was obtained.

 Results: As of 2 April 2018, among 508 requests for avelumab across 37 countries, 61 requests were received in Australia: 54 were approved and 7 were medically rejected. Median age was 77 y (range, 45-95) and 66.7% of patients were male. 49 patients have received avelumab. Among 34 patients on treatment >3 mo, physician-assessed objective responses were observed in 8 of 16 evaluable patients (23.5%; 4 CR [11.8%] and 4 PR [11.8%; including 1 patient with HIV]); 18 patients (52.9%) had either unevaluable tumors or no data reported. Median time to response was 49 d (range, 28-140). No new safety signals were reported. The EAP is ongoing but closing in 2018 as required post-approval (US closed in 2017).

 Conclusions: The avelumab EAP provides an alternative treatment option for patients with mMCC with PD on/after chemotherapy or are ineligible for either chemotherapy or clinical trials. In a real-world setting, avelumab showed efficacy and safety consistent with JAVELIN Merkel 200.