Medivir AB announced that the first patient with hepatocellular carcinoma (HCC) has started treatment in phase 2a with the candidate drug fostroxacitabine bralpamide (fostrox) in combination with Lenvima®?. In Medivir's ongoing phase 1b/2a study, fostrox is given in combination with two other drugs, either with L envima®?, a tyrosine kinase inhibitor, or with Keytruda®?, an anti-PD-1 checkpoint inhibitor. The study is an open-label, multicenter study and includes patients with HCC for whom current first- or second-line treatment has proven ineffective or is not tolerable.

The phase 1b part of the study evaluates which dose of fostrox is most appropriate for the next phase. This dose is then used in the phase 2a part of the study where safety and signals of efficacy are further evaluated. The preliminary results from the recently completed phase 1b for fostrox in combination with Lenvima™?

were positive with a good safety and tolerability profile where no dose-limiting toxicity was observed. The recommended dose (RP2D) for fostrox in this combination arm was set at 30 mg. 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.