Late-stage clinical pharmaceutical company Cinclus Pharma Holding AB (STO:CINPHA) announced on Friday that it will initiate the Phase III HEEALING 1 study of linaprazan glurate for the treatment of erosive gastroesophageal reflux disease (GERD), following positive regulatory feedback.

The first patient screening is expected in September 2025, with topline results anticipated in 2026.

The study will enrol about 500 patients across up to 100 clinical sites in seven European countries. Its primary endpoint is to demonstrate superiority over lansoprazole, a proton pump inhibitor, in healing moderate to severe erosive GERD after four weeks, with additional endpoints assessing healing and symptom relief up to eight weeks.

Cinclus and its partner Zentiva see linaprazan glurate as a potential first potassium-competitive acid blocker (PCAB) to reach the European market, representing a significant commercial opportunity.

The US Food and Drug Administration (FDA) has also provided feedback, allowing study initiation contingent on protocol adjustments, with a follow-up US trial, HEEALING 2, planned after topline results from HEEALING 1.

Cinclus signed a licensing and commercialisation agreement with Zentiva earlier this year valued at up to EUR220m, plus tiered royalties starting just below 20% and exceeding 20% at higher sales levels. A milestone payment is tied to the topline results of HEEALING 1, expected in the second half of 2026.