Arena to Present New Information on Its Pulmonary Hypertension Therapy Ralinepag in Barcelona

Arena Pharmaceuticals will present new information in Barcelona this weekend on its pulmonary hypertension therapy ralinepag, which a clinical trial showed improved patients’ heart blood vessel resistance and exercise capacity.

The two presentations at the European Society of Cardiology Congress, Aug. 26-30, will focus on the results of preclinical-trial studies in rats and lab-grown cells from humans with pulmonary arterial hypertension, or PAH. The lab-grown cells will include platelets, lung arteries, and lung artery smooth muscle cells.

Prostacyclin is a hormone that widens blood vessels and prevents blood platelets from clumping. Ralinepag (APD811) can reverse blood vessel narrowing and platelet clumping by using the prostacyclin pathway to bind to prostacyclin receptors. It can also prevent the growth of vascular smooth muscle cells, which make blood vessel walls thicker.

“The preclinical pharmacology data continue to support our belief that ralinepag is a potential best-in-class oral prostacyclin therapy,” Amit D. Munshi, the president and CEO of Arena, said in a press release. “The acceptance of the scientific data presentation at ESC [the Barcelona conference] is representative of the enthusiasm of clinical investigators and scientists to continue exploring the novel profile of ralinepag.”

During the presentations Arena will compare ralinepag’s ability to target the prostacyclin receptor, versus approved drugs’ ability to do so.

One presentation will be titled “Comparative receptor pharmacology, preclinical efficacy and pharmacokinetics of a novel, next-generation prostacyclin receptor agonist, ralinepag (APD811), in humans and rats.” The title of the other will be “APD811 (ralinepag), a novel non-prostanoid IP receptor agonist, has potent antiproliferative and vasorelaxant properties in human pulmonary artery.”

In July 2017, Arena shared the results of a Phase 2 clinical trial (NCT02279160) assessing ralinepag’s ability to improve the symptoms of 61 adults with PAH. The therapy significantly improved pulmonary vascular resistance, which limits blood flow in the heart, and patients’ exercise capacity after 22 weeks of treatment.

Pulmonary vascular resistance is a commonly used measure of pulmonary hypertension treatments’ effectiveness. Researchers believe it is correlated with the outcome of the disease.

Adverse events during the Phase 2 trial were consistent with other prostacyclin treatments used to manage PAH, Arena reported.

Patients who completed the trial were eligible to enter an open-label extension trial (NCT02279745) assessing the long-term safety of ralinepag, and patients’ ability to tolerate it.

Arena has also announced that it is planning a larger Phase 3 trial of the drug.