Basilea Pharmaceutica Ltd. (SIX: BSLN) announced today the completion of patient enrolment in its phase 1 study with the oral formulation of the novel tumor checkpoint controller BAL101553 in brain cancer patients.
The study included 28 patients with progressive or recurrent glioblastoma (GBM), the most aggressive primary brain tumor, or high-grade glioma. Patients received once-daily oral BAL101553. The maximum tolerated dose (MTD) was determined at 30 mg per day. Dose-limiting adverse events included gait disturbances, hallucinations and confusion, which were all reversible.
Dose levels up to and including 25 mg per day were well tolerated. Clinical antitumor activity of BAL101553 was shown with one exceptional, long-lasting responder still on treatment, whose brain tumor tissue displayed strong expression of the potentially response-predictive biomarker EB1 (end-binding protein 1). In addition, five further patients experienced stable disease as a best response.
Dr. Marc Engelhardt, Basilea’s Chief Medical Officer, said: “The results from the phase 1 study in brain cancer patients indicate a manageable safety and tolerability profile, which is consistent with the safety profile observed for BAL101553 in the treatment of other advanced solid tumors. The observation of an exceptional, durable response in a GBM patient whose tissue was strongly positive for EB1 is encouraging, especially as we had previously identified EB1 as a potential response-predictive biomarker for BAL101553 based on comprehensive preclinical studies in GBM models. We are now assessing the potential utility of EB1 to support a biomarker-driven clinical study with BAL101553 in GBM and other cancer types. This would subsequently allow using BAL101553 as a targeted therapy in patients whose tumors show high EB1 expression.”