Primary liver cancer, of which hepatocellular carcinoma (HCC) is the most common type, is the third leading cause of cancer-related death globally. Although there are treatments that can prolong the lives of patients with HCC, not all patients respond to these treatments, resulting in a continued high mortality rate.
Medivir aims to fostrox is set to become the first approved second-line treatment for HCC. The candidate offers a targeted approach that limits damage to healthy liver cells by delivering the cytotoxic agent directly to the tumor.
Promising phase Ib/IIa data in HCC
Fostrox is currently in the final stages of an ongoing Phase Ib/IIa study in combination with Eisais lenvatinib mesylate (Lenvima). Tecentriq/Avastin is the recommended first-line treatment, but when patients move on to second-line treatment, options are limited.
Phase Ib/IIa data have shown that fostrox and lenvatinib are well tolerated with promising antitumor activity. Results presented at ESMO in September indicated an efficacy that is better than that expected with Lenvima alone with a median time to progression of 10,9 months, an objective response rate of 24 percent and a disease control rate of 81 percent. In addition, the tolerability of the combination allows patients to remain on treatment for longer, leading to long-term benefits.
Expanded clinical collaboration with Eisai
In the announced collaboration, Medivir and Eisai will conduct a randomized Phase IIb study comparing fostrox plus lenvatinib to lenvatinib monotherapy as a second-line treatment for HCC. Eisai will provide lenvatinib for the study, while Medivir will retain full rights to fostrox. A Joint Development Committee will oversee the design and conduct of the study, starting with a dose optimization phase to determine the ideal fostrox dose before moving on to broader testing.
In a press release, it says Medivir CEO Jens Lindberg:
“In our ongoing Phase 1b/2a study, fostrox + lenvatinib has been shown to have a manageable safety profile and encouraging antitumor activity in second-line liver cancer patients. Fostrox + lenvatinib has the potential to become the first approved treatment option after first-line immunotherapy combination therapy, a population with an estimated market value of over $2,5 billion by 2030.”
Dr. Takashi Owa, Chief Scientific Officer, Senior Vice President, Eisai also commented on the collaboration:
“There is still an unmet need for patients suffering from hepatocellular carcinoma (HCC), a major contributor to cancer-related deaths. The results from the ongoing Phase 1b/2a study of the combination of fostrox and lenvatinib in second-line advanced liver cancer are encouraging. Our collaboration with Medivir for the upcoming randomized Phase 2b study aims to advance a new treatment option for patients with HCC.”