Combining mogamulizumab with nivolumab of no benefit in advanced solid tumours

The addition of mogamulizumab to nivolumab falls short of improving efficacy of the latter in the treatment of patients with locally advanced or metastatic solid tumours, according to the results of a phase I/II trial.

The trial consisted of dose-finding (phase I) and dose expansion (phase II) phases. A total of 114 patients treated with mogamulizumab 1 mg/kg plus nivolumab 240 mg in phases I (n=4) and II (n=110) were assessed for safety and efficacy.

In phase I, no dose-limiting toxicities occurred with mogamulizumab 1 mg/kg every week for cycle 1 followed by 1 mg/kg every 2 weeks plus nivolumab 240 mg every 2 weeks intravenously. Therefore, the same dose level was used in phase II. Treatment was given for up to 24 months.

Nearly all patients (96.5 percent) had received prior anticancer regimens, with the majority (65.8 percent) having exposed to at least two prior regimens. Best response to the most recent, previous anticancer regimen was complete response in 2.3 percent, partial response in 4.6 percent, stable disease in 33.3 percent, or progressive disease in 59.8 percent among the 87 patients with available data. None of the patients had prior exposure to checkpoint inhibitor therapies.

The combination of mogamulizumab plus nivolumab showed acceptable safety and tolerability, the primary study endpoint. The most common treatment-related grade ≥3 adverse events were drug eruption rash, transaminase increases, and anaemia.

In terms of efficacy, the combination yielded an objective response rate of 10.5 percent (95 percent CI, 5.6–17.7; three complete and nine partial responses) and a disease control rate of 36.8 percent. The median duration of response was 14.4 months.

The median progression-free survival was 2.6 (95 percent CI, 2.3–3.1) months, while median overall survival was 9.5 (95 percent CI, 5.9–13.5) months.