Updated efficacy of avelumab in patients with previously treated metastatic Merkel cell carcinoma after ≥1 year of follow-up: JAVELIN Merkel 200, a phase 2 clinical trial.

Abstract

BACKGROUND:

Merkel cell carcinoma (MCC) is a rare, aggressive skin cancer associated with poor survival outcomes in patients with distant metastatic disease (mMCC). In an initial analysis from JAVELIN Merkel 200, a phase 2, prospective, open-label, single-arm trial in mMCC, avelumab-a human anti-programmed death-ligand 1 (PD-L1) monoclonal antibody-showed promising efficacy and a safety profile that was generally manageable and tolerable. Here, we report the efficacy of avelumab after ≥1 year of follow-up in patients with distant mMCC that had progressed following prior chemotherapy for metastatic disease.

PATIENTS AND METHODS:

Patients received avelumab 10 mg/kg by 1-h intravenous infusion every 2 weeks until confirmed disease progression, unacceptable toxicity, or withdrawal. The primary endpoint was best overall response. Secondary endpoints included duration of response (DOR), progression-free survival (PFS), and overall survival (OS).

RESULTS:

Patients (N = 88) were followed for a minimum of 12 months. The confirmed objective response rate was 33.0% (95% CI, 23.3%-43.8%; complete response: 11.4%). An estimated 74% of responses lasted ≥1 year, and 72.4% of responses were ongoing at data cutoff. Responses were durable, with the median DOR not yet reached (95% CI, 18.0 months-not estimable), and PFS was prolonged; 1-year PFS and OS rates were 30% (95% CI, 21%-41%) and 52% (95% CI, 41%-62%), respectively. Median OS was 12.9 months (95% CI, 7.5-not estimable). Subgroup analyses suggested a higher probability of response in patients receiving fewer prior lines of systemic therapy, with a lower baseline disease burden, and with PD-L1-positive tumors; however, durable responses occurred irrespective of baseline factors, including tumor Merkel cell polyomavirus status.

CONCLUSIONS:

With longer follow-up, avelumab continues to show durable responses and promising survival outcomes in patients with distant mMCC whose disease had progressed after chemotherapy.

TRIAL REGISTRATION:

Clinicaltrials.gov identifier: NCT02155647.

• Authors: Howard L Kaufman, Jeffery S Russell, Omid Hamid, Shailender Bhatia, Patrick Terheyden, Sandra P D'Angelo, Kent C Shih, Céleste Lebbé, Michele Milella, Isaac Brownell, Karl D Lewis, Jochen H Lorch, Anja von Heydebreck, Meliessa Hennessy, Paul Nghiem
• Journal: Journal for immunotherapy of cancer (J Immunother Cancer) Vol. 6 Issue 1 Pg. 7 (01 19 2018) ISSN: 2051-1426 [Electronic] England
• PMID: 29347993 (Publication Type: Clinical Trial, Phase II, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antibodies, Monoclonal
• Antibodies, Monoclonal, Humanized
• avelumab

Topics

• Aged
• Antibodies, Monoclonal (pharmacology, therapeutic use)
• Antibodies, Monoclonal, Humanized
• Carcinoma, Merkel Cell (drug therapy, pathology)
• Female
• Follow-Up Studies
• Humans
• Male
• Middle Aged
• Neoplasm Metastasis
• Skin Neoplasms (drug therapy, pathology)
• Time Factors