Actelion Receives CRL for Macitentan CTEPH Indication

Actelion Pharmaceuticals has received a Complete Response Letter (CRL) from the US Food and Drug Administration (FDA) for its supplemental New Drug Application (sNDA) of macitentan (OPSUMIT) for the treatment of adults with inoperable chronic thromboembolic pulmonary hypertension (CTEPH).

Actelion, a company under Janssen Pharmaceutical of Johnson & Johnson, was pursuing an indication that would allow the use of macitentan for the improvement of pulmonary vascular resistance (PVR) and exercise capacity in adults with CTEPH. The company now intends to work closely with the FDA to review the outlined information and “gain a full understanding of the next steps.”

“We are committed to making a difference in the lives of people living with pulmonary hypertension and CTEPH,” said Martin Fitchet, MD, the global head Research & Development for Actelion, in a statement.

The FDA had indicated in its CRL that additional data of macitentan for the treatment of CTEPH is needed. An orally active endothelin receptor antagonist, macitentan is currently approved for the treatment of patients of pulmonary hypertension (PAH)—more particularly, for the reduction of disease progression and hospitalization risks associated with PAH.

Its sNDA for the CTEPH indication was supported by clinical results from the MERIT-1 trial, a phase 2 study assessing the efficacy, safety, and tolerability of 10 mg macitentan in patients with inoperable CTEPH. The data, previously published in September 2017, showed that 40 patients randomly assigned to the therapy reported a geometric mean pulmonary vascular resistance (PVR) decrease of 73.0% from baseline at week 16—a statistically significant rate. Patients treated with placebo reported a mean decrease of 87.2% in the same time period (95% CI: 0.70 — 0.99; P = .041).

Common adverse events in treated patients were peripheral edema (9 [23%]) and decreased hemoglobin (6 [15%]). Investigators indicated macitentan was well-tolerated among its patients.