ProKidney is dropping an ex-US Phase III study for its chronic kidney disease (CKD) cell therapy rilparencel, following discussions with regulatory experts and ex-US Food and Drug Administration (FDA) officials.

The US-based biotech’s Phase III program consisted of two studies; the REGEN-006 (PROACT 1) (NCT05099770) study in the US and the REGEN-016 (PROACT 2) (NCT05286853) study in ex-US countries. Both trials are designed to investigate the agent, which is also known as REACT, in type 2 diabetes and CKD.

Following discussions to finalise rilparencel’s regulatory plans in the US, North Carolina-based ProKidney will drop the REGEN-016 trial, a move which the company says will save between $150m and $175m. The company closed a $140m public offering of class A ordinary shares in June 2024, which would extend its cash runway to mid-2026.

Rilparencel, which was granted regenerative medicine advanced therapy (RMAT) designation by the FDA in October 2021, is a regenerative therapy. Administered through intra-renal injection, it utilises autologous renal cells embedded in a gelatin-based hydrogel. These cells are designed to stimulate the regeneration of functional kidney tissue, aiming to restore kidney function based on organ regeneration technology.

Enrolment into the REGEN-006 study was put on hold last year after ProKidney announced that it was updating the protocol. The study, which previously enrolled patients with mild-moderate to severe CKD, was updated to focus on patients with the most severe CKD. The two trials were expected to enrol up to 600 patients each. Subjects were randomised 1:1 into either a rilparencel treatment arm and undergo a kidney biopsy, or a sham control arm.

In the announcement accompanying the update, ProKidney’s CEO Bruce Culleton said: “We are confident that this strategic shift in our Phase III programme is the most expeditious and resource efficient approach to bring rilparencel to market in the US, our highest priority market.”