4657 - Avelumab in European patients (pts) with metastatic Merkel cell carcinoma (mMCC): experience from an ad hoc expanded access program (EAP)

Background

Avelumab—a human anti–PD-L1 IgG1 monoclonal antibody—showed favorable efficacy and safety in pts with mMCC 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 European pts with mMCC.

Methods

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

Results

As of April 30, 2018, of 521 requests for avelumab across 37 countries, 343 were received in Europe: 305 were approved (including 20 for immunocompromised [IC] pts), 29 were medically rejected, and 9 were withdrawn. Most requests were from France (n = 96) and Italy (n = 87). 275 European pts received avelumab. Median age was 73 y (range, 28-95 y), and 69% of pts were male. Of 250 pts on treatment >3 mo, 145 (58%) had either unevaluable tumors or no data reported (including 11 IC pts). Of 105 evaluable pts, physician-assessed objective responses were observed in 54.3% (57 pts; including 3 IC pts [2 CR and 1 PR]) with 25.7% CR (27 pts) and 28.6% PR (30 pts). Median duration of treatment in pts with response was 195 d (range, 30-570 d). The disease control rate in evaluable pts was 75%. No new safety signals were reported. The EAP is ongoing but closing in 2018 as required postapproval.

Conclusions

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

Clinical trial identification

Trial Protocol Number: NCT03089658.

Legal entity responsible for the study

Merck KGaA, Darmstadt, Germany.

Funding

Funding was provided by Merck, KGaA, Darmstadt, Germany in alliance with Pfizer, Inc.

Editorial Acknowledgement

Medical writing support was provided by ClinicalThinking Inc., Hamilton, NJ, USA.

Disclosure

P. Nathan: Honoraria: AstraZeneca, Bristol-Myers Squibb, Novartis, Immunocure, Roche, Pfizer; Membership on any entity’s Board of Directors or advisory committees: AstraZeneca, Bristol-Myers Squibb, Novartis, Immunocure, Roche, Pfizer. V. Kasturi, M. Hennessy, J. Reed: Employee: EMD Serono. P.A. Ascierto: Consultancy (Includes expert testimony): Bristol-Myers Squibb, Roche-Genentech, Merck Sharp & Dohme, Array, Novartis, Amgen, Merck-Serono, Pierre-Fabre, Incyte, Genmab, Newlink Genetics, Medimmune, Syndax, AstraZeneca; Research Funding: Bristol-Myers Squibb, Roche-Genentech, Array; Membership on any entity’s Board of Directors or advisory committees: Bristol-Myers Squibb, Roche-Genentech, Array, Novartis. A. Engelsberg: Employee: Pfizer Pharma GmbH. S. Hariharan: Employee, Equity ownership: Pfizer. C. Lebbé: Financial interest: Roche, BMS, Novartis, Amgen, MSD. All other authors have declared no conflicts of interest.