Dive Brief:
- It's not good news for rare disease company Acceleron Pharma – topline results from the DART Phase 2 study showed that the combination of dalantercept and axitinib failed to meet the primary endpoint in patients with advanced renal cell carcinoma (RCC), and as a result the drug's development has been dropped.
- Patients with advanced RCC treated with both dalantercept and axitinib showed progression-free survival (PFS) of 6.8 months, compared with 5.6 months for placebo plus axitinib, and dalantercept did not decrease the rate of disease progression or death.
- The results weren't particularly positive for the secondary endpoints either. The PFS for previously treated patients given the drug was 8.1 months compared with 7.0 months for the placebo arm and the objective response rate was actually lower for the active arm (19%) than the placebo arm (25%).
Dive Insight:
Dalantercept inhibits angiogenesis by blocking the interaction between the BMP9 protein and the activin receptor-like kinase 1 (ALK1), and Acceleron hoped that it would have potential in combination with angiogenesis inhibitors based on the VEGF target by bringing together two different modes of action.
"We designed a robust Phase 2 study to evaluate the efficacy of dalantercept in combination with anti-VEGF therapy in advanced renal cell carcinoma patients whose disease has progressed on prior anti-VEGF therapy. We are disappointed by the results given the need for new agents that improve outcomes for patients with advanced RCC," said Habib Dable, president and CEO of Acceleron. "Based on the lack of efficacy, we are discontinuing the development of dalantercept."
This doesn't seem to be worrying investors, though; after a brief wobble where its share price dropped by just 4%, it climbed back up $29.64 by close of market yesterday. Acceleron will now focus its hopes on its lead drug, the TGF-beta inhibitor luspatercept. This is being developed with Celgene, under the terms of a 2011 agreement covering hematologic diseases.
Luspatercept is in Phase 3 in myelodysplastic syndromes and beta-thalassemia, with a Phase 2 trial planned in myelofibrosis. Earlier this month, Acceleron and Celgene announced that they had reached target enrollment in the two Phase 3 studies, with topline results expected for both in mid-2018.