Gilead receives FDA approval for PAH combo

Gilead has received FDA approval for the use of Letairis in combination with tadalafil for the treatment of pulmonary arterial hypertension.

The approval comes on the back of data from the AMBITION study involving 605 patients. The study showed that combination therapy Letairis and tadafil demonstrated superiority over Letairis or tadalafil alone cutting the risk of treatment failure by 50%.

Letairis is an endothelin receptor antagonist and was approved in 2007 as monotherapy for PAH to improve exercise ability and delay disease progression.

Ronald Oudiz, professor of medicine at UCLA, said: “Based on the data supporting today's approval, we now know that patients receiving ambrisetan and tadalafil up front are less likely to experience disease progression or be hospitalised, and have more improvement in their exercise ability than patients receiving either effective therapy alone. 

“This combination represents a new treatment strategy for patients living with this debilitating and life-threatening disease.”

Gilead's new combination treatment will now compete with the likes of Actelion's Opsumit (macitentan), the successor to the blockbuster drug Tracleer (bosentan).

Additionally there will be competition from Bayer's Adempas (riociguat), which was cleared by the FDA in 2013, and United Therapeutics' Remodulin (treprostinil).

Analysts have predicted that the PAH market will grow from $4bn in 2013 to $5.2bn in 2020.

PAH is a debilitating disease characterised by constriction of blood vessels in the lungs leading to high pulmonary arterial pressures.

This high pressure makes it difficult for the heart to pump blood through the lungs, leaving patients with a number of symptoms such as shortness of breath which can lead to heart failure.