Dalantercept and Axitinib in Renal Cell Carcinoma

Combining dalantercept with axitinib treatment may improve clinical outcomes—with an acceptable safety profile—for previously treated patients with renal cell carcinoma (RCC), according to results from the first part of the 2-part DART study (ClinicalTrials.gov Identifier: NCT01727336).¹

Axitinib, a tyrosine kinase inhibitor (TKI) that targets vascular endothelial growth factor (VEGF) signaling, can improve clinical outcomes for previously-treated patients with RCC by preventing angiogenesis. Dalantercept inhibits angiogenesis by targeting activin receptor-like kinase 1 (ALK1), which is involved in angiogenic processes distinct from VEGF. For this study, researchers attempted to determine the safety profile and efficacy of dalantercept when administered with axitinib, as well as the optimal dalantercept dose.

Of 29 enrolled patients, 6 patients received 0.6 mg/kg of dalantercept, 9 patients received 0.9 mg/kg, and 14 received 1.2 mg/kg; the authors concluded that 0.9 mg/kg was the optimal dose based on toxicity concerns.

The objective response rate was defined as the rate of complete or partial responses; there were, however, no complete responses observed. Seven patients achieved a partial response, 17 had stable disease, 4 had disease progression, and 1 patient was not evaluable.

No grade 4 adverse events or treatment-related deaths were recorded. The most common adverse events were fatigue and diarrhea.

The authors concluded that: the optimal dalantercept dose was 0.9 mg/kg, the treatment combination had a manageable safety profile, and the combination appeared to be clinically active. Further study is needed.

Reference

1. Voss MH, Bhatt RS, Plimack ER, et al. The DART Study: Results from the dose-escalation and expansion cohorts evaluating the combination of dalantercept plus axitinib in advanced renal cell carcinoma. Clin Cancer Res. 2016 Dec 28. doi: 10.1158/1078-0432.CCR-16-2395 [Epub ahead of print]