Gilead abandons development of PAH drug cicletanine

US biotech firm Gilead Sciences (Nasdaq: GILD), the world leader in HIV/AIDS drugs, has discontinued development of cicletanine, a potential treatment for pulmonary arterial hypertension, after the drug failed to meet a primary efficacy endpoint in a mid-stage clinical trial, it was revealed in a posting on the US National Institutes of Health’s on-line database cinicaltrials.gov.

Gilead began enrolling patients in the Phase II trial of cicletanine in 2009 (The Pharma Letter March 30, 2009). The study was designed to compare the efficacy, safety and tolerability of cicletanine to placebo in patients with PAH and enrolled 160 patients at around 60 investigational sites worldwide.

Gilead had acquired cicletanine, an off-patent compound, in 2008 from Navitas Assets for an initial payment of $10.9 million, plus the potential for future payments if certain development and regulatory milestones were met (TPL June 9, 2008). The deal gave Gilead rights to cicletanine as a monotherapy for PAH and other indications in the USA. Cicletanine was developed by France’s Ipsen and is approved in certain European countries for hypertension under the trade name Tenstaten.