Can reformulation of an AstraZeneca castoff rival Takeda's new heartburn drug? Here's a $26M bet on yes
Linaprazan didn’t make much of a mark at AstraZeneca. Despite showing promise in early-stage studies, the potassium competitive acid blocker, or PCA-B, failed to beat Nexium, the pharma giant’s blockbuster proton pump inhibitor in treating acid reflux. The drug was then unceremoniously purged from the pipeline.

As the preclinical project leader in Mölndal, Sweden, Kjell Andersson witnessed the rise and fall of linaprazan. Having helped develop Nexium, he also knew that about 40% of patients still suffer from symptoms, including heartburn and chest pain, even if they’re on treatment. So together with colleagues Mikael Dahlström and Peter Unge, he purchased rights to prodrugs of linaprazan and launched his own startup.
Cinclus Pharma is now 6 years old and has just landed $26 million (SEK 250 million) to fund a Phase II trial of its lead drug, X842.
The reason why linaprazan didn’t work was that it was eliminated too quickly from the body, so goes the company’s theory, and the duration of acid blocking was thus too short. They point to Takeda’s vonoprazan, a fellow PAC-B drug, and its approval in Japan to highlight the potential of the approach.

Outside of Japan, vonoprazan is now in the hands of Phathom Pharma, the Takeda/Frazier spinout dedicated to GI diseases.
With the help of Fourth Swedish National Pension Fund as well as existing shareholders including Bengt Julander, Jonas Sjögren and Recipharm Venture Fund, Cinclus expects to start a Phase II in gastroesophageal reflux disease (GERD) later this year.
“The introduction of Losec and other proton pump inhibitors in the 1980s and the 1990s was a major step forward in the treatment of GERD,” CEO Andersson said in a statement, referring to another drug he was involved in steering. “However, there is potential to help significantly more patients to a better life by developing even more efficient drugs.”
AstraZeneca, meanwhile, has moved on from the legacy field, selling Losec and Nexium off to a pair of German drugmakers.