Biotechnology company United Therapeutics Corporation (Nasdaq:UTHR) announced on Wednesday that it has entered into an amended agreement with Arena Pharmaceuticals, a subsidiary of Pfizer Inc (NYSE:PFE), to eliminate all royalty obligations on ralinepag in exchange for a USD525m upfront payment.

This transaction removes the previously agreed low double-digit royalty on net sales across all ralinepag formulations, including oral and inhaled versions.

The agreement strengthens United Therapeutics' commercial position ahead of a potential launch of oral ralinepag, which is under review by the US Food and Drug Administration (FDA) for pulmonary arterial hypertension (PAH), with an action date of 24 June 2027.

The company is also developing a dry powder inhaled formulation of ralinepag, with plans to investigate its potential in pulmonary hypertension associated with interstitial lung disease, idiopathic pulmonary fibrosis and progressive pulmonary fibrosis.

United Therapeutics remains subject to two potential milestone payments under the amended licensing arrangement: USD250m following the first US marketing approval for inhaled ralinepag for PAH, and USD150m following the first qualifying approval of oral ralinepag in Japan, France, Italy, the UK, Spain or Germany.

Ralinepag remains investigational and has not been approved for any indication in any jurisdiction.