Eisai has announced the results of a Phase Ib clinical trial of its multiple-receptor, tyrosine kinase inhibitor lenvatinib mesylate (lenvatinib) in combination with the anti-PD-1 antibody pembrolizumab developed by Merck & Co in patients with selected solid tumours.
The combination regimen is being conducted jointly by the two firms.
The multicentre, open-label Phase Ib/II clinical study aims to analyse the efficacy and safety of lenvatinib in combination with pembrolizumab.
In the Phase Ib part of the trial, which was carried out to analyse and confirm the maximum tolerated dose (MTD), 13 patients with selected solid tumours that had progressed after treatment with approved therapies, or for which there are no standard effective therapies available, were administered either 24mg or 20mg of lenvatinib daily and 200mg of pembrolizumab intravenously every three weeks.
Out of the 13 patients, eight had renal cell carcinoma, two had endometrial cancer, another two had non-small-cell lung cancer and one patient had melanoma.
According to the latest results of the Phase Ib part of the study, dose-limiting toxicities (DLTs) were reported in two of three patients in the lenvatinib 24mg / pembrolizumab 200mg group.
No DLTs were reported in the lenvatinib 20mg / pembrolizumab 200mg group of ten patients, and the MTD was confirmed as 20mg of lenvatinib per day / 200mg of pembrolizumab every three weeks.
The objective response rate, one of the study's secondary endpoints, was 69.2%.
Grade 3 or higher Treatment-Emergent Adverse Events (TEAEs) were observed in 69.2% of patients, and no patients had discontinued treatment due to TEAEs.
The three most frequently observed adverse events were decreased appetite, diarrhoea and fatigue.
Eisai's oncology business group chief medicine creation officer said: "From the results of this study for patients who had progressed after treatment with approved therapies, or for which there are no standard effective therapies available, we are encouraged to further explore the combination of lenvatinib and pembrolizumab in the next stage of clinical development."
The Phase II of the study is currently being conducted in the US, while a Phase Ib clinical study in Japan is also being planned.