Medivir starts patient dosing in phase 2a study of fostrox in combination with Lenvima to treat hepatocellular carcinoma

Medivir AB, a pharmaceutical company focused on developing innovative cancer treatments in areas of high unmet medical need, announced that the first patient with hepatocellular carcinoma (HCC) has begun phase 2a treatment with the candidate drug fostroxacitabine bralpamide (fostrox) in combination with Lenvima. In Medivir's ongoing phase 1b/2a trial, fostrox is combined with one of two other drugs: Lenvima, a tyrosine kinase inhibitor, or Keytruda, an anti-PD-1 checkpoint inhibitor.

The research is a multicenter, open-label study that includes patients with HCC whose current first- or second-line treatment has proven ineffective or is intolerable. The study's phase 1b evaluates which dose of fostrox is most suitable for the next phase. This dose is then used in the phase 2a portion of the trial to assess safety and efficacy signals.

The preliminary findings of the recently completed phase 1b study for fostrox in combination with Lenvima were positive, with a good safety and tolerability profile and no dose-limiting toxicity. In this combination arm, the recommended dose (RP2D) for fostrox was established at 30 mg. "It is really exciting that we have been able to initiate the important expansion phase of the study so rapidly, with the first patient now being treated with fostrox and Lenvima in phase 2a.

"The medical need for a novel, effective treatment is enormous, as is interest from both investigators and patients, which is why I think that patient recruitment for this part of the study will be completed quickly," says Pia Baumann, chief medical officer at Medivir AB. The results from this study will form the basis for the future development plan for fostrox. A total of up to 30 patients with HCC are planned to be recruited in the study that is being conducted at 14 clinics in Great Britain, Spain and South Korea. In the second combination arm where fostrox is administered together with Keytruda, the phase 1b dose escalation is still ongoing. Fostrox is a pro-drug designed to selectively treat liver cancers and to minimize side effects. It has the potential to become the first liver-targeted and orally administered drug for patients with HCC and other forms of liver cancer. Fostrox has completed a phase 1b monotherapy study, and a combination study in HCC currently ongoing. Primary liver cancer is the third leading cause of cancer-related deaths worldwide and hepatocellular carcinoma (HCC) is the most common cancer that arises in the liver.

Although existing therapies for advanced HCC can extend the lives of patients, treatment benefits are insufficient and death rates remain high. There are 42,000 patients diagnosed with primary liver cancer per year in the US and current five-year survival is 11 per cent. HCC is a heterogeneous disease with diverse etiologies, and lacks defining mutations observed in many other cancers. This has contributed to the lack of success of molecularly targeted agents in HCC. The limited overall benefit, taken together with the poor overall prognosis for patients with intermediate and advanced HCC, results in a large unmet medical need.

Medivir develops innovative drugs with a focus on cancer where the unmet medical needs are high. The drug candidates are directed toward indication areas where available therapies are limited or missing and there are great opportunities to offer significant improvements to patients.