Arena bags big deal with United for PAH drug ralinepag

Arena’s run of positive news continues, with a massive $800 million upfront licensing deal with United Therapeutics for its pulmonary arterial hypertension drug ralinepag.

The global deal, which also includes $400 million in milestones and double-digit royalties, comes on the heels of well-regarded phase 2 data with the oral prostacyclin receptor agonist in PAH that caused Arena’s shares to soar when it was released last year. It also gives the company a partner with a deep knowledge of PAH and a need to advance new drugs to complement an aging PAH portfolio.

“We believe ralinepag has the potential to transform the treatment of PAH,” says Arena’s CEO Amit Munshi, and will allow the company to focus its efforts on other pipeline drugs including etrasimod and olorinab for inflammatory bowel disease.

Ralinepag’s mid-stage data threw down a gauntlet in front of Johnson & Johnson, whose rival drug Uptravi (selexipag) has been making gains in the PAH market with sales rising at a healthy pace to $422 million in the first nine months of this year. Uptravi was a key driver for J&J’s $30 billion acquisition of Actelion, which spearheaded a move into PAH for the pharma giant.

For United Therapeutics, the deal gives it a new late-stage candidate for PAH at a time when its own franchise in this therapeutic category—focused mainly on treprostinil in oral, inhaled and injectable formats—is facing the threat of competition from generics. Sales of its injectable Remodulin product declined by a third in the third quarter, and while inhaled version Tyvaso is still growing it is also facing patent challenges.

Ralinepag gives it a new small-molecule agonist that according to Arena has advantages over Uptravi, which EvaluatePharma predicts will be the top-selling PAH drug in 2022. The company reckons ralinepag has a longer half-life and smaller peak to trough fluctuations than selexipag that could make it a best-in-class therapy.

United Therapeutics CEO Martine Rothblatt, Ph.D., says she has been “impressed with the clinical development plan and FDA coordination being managed by Arena” and is “confident that after achieving FDA approval via at least one of its several different potential regulatory pathways to success, this product will help greater than 10,000 patients annually from the 2020s and well into the 2030s, while complementing our existing portfolio of PAH therapies.”

It’s not the first time this year the company has decided to absorb a rival candidate to boost its own pipeline. In April, it acquired SteadyMed for $216 million, claiming control of its Trevyent combination that pairs treprostinil with a proprietary pump device, and followed that in September with a license deal with MannKind for a dry powder formulation of the drug.

It’s also working to defend its franchise with in-house candidates, including a combination of Tyvaso with epoprostenol receptor agonist esuberaprost that should have an important readout in March 2019.

PAH is a type of high blood pressure that occurs in the pulmonary artery that reaches the lungs from the right-hand side of the heart. Over time, the increased blood pressure can damage the heart. It’s become an area of intense research activity in the biopharma industry, with upward of 40 candidates in clinical trials, so is expected to become a highly competitive category in the coming years.