ProKidney has announced it will discontinue its ex-US Phase III clinical trial, REGEN-016 (PROACT 2), for its cell therapy rilparencel, focusing instead on the US market. This decision follows discussions with regulatory experts and former FDA officials and is projected to save the company between $150 million and $175 million.
The Phase III program initially consisted of two studies: REGEN-006 (PROACT 1) in the US (NCT05099770) and REGEN-016 (PROACT 2) in ex-US countries (NCT05286853). Both trials are designed to investigate rilparencel, also known as REACT, in patients with type 2 diabetes and CKD.
Strategic Shift to US Market
According to ProKidney's CEO, Bruce Culleton, the strategic shift to prioritize the PROACT 1 trial in the US is the most efficient approach to bring rilparencel to market. The company believes that the PROACT 2 trial is not necessary to achieve regulatory approval in the US.
Rilparencel: A Regenerative Cell Therapy
Rilparencel, granted regenerative medicine advanced therapy (RMAT) designation by the FDA in October 2021, is administered via intra-renal injection. It uses autologous renal cells embedded in a gelatin-based hydrogel, designed to stimulate the regeneration of functional kidney tissue and restore kidney function.
REGEN-006 Trial Update
Enrollment into the REGEN-006 study was previously put on hold to update the protocol. The study now focuses on patients with the most severe CKD, specifically stage 4 CKD and late stage 3b CKD with albuminuria. The trial is expected to enroll approximately 685 patients, randomized 1:1 to either the rilparencel treatment arm or a sham control arm.
Positive Phase 2 Data
Interim results from the REGEN-007 Phase 2 clinical trial (NCT05018416) evaluating rilparencel in patients with CKD caused by diabetes showed promising results. With a data cutoff of May 7, 2024, all 13 patients in one group who had 12 months of follow-up after their second injection demonstrated stabilized kidney function for 18 months, with an average change in eGFR from baseline of -1.3 ml/min/1.73m2 at 18 months. There were no serious adverse events related to rilparencel among the 49 patients who received at least one injection.
Culleton stated that the REGEN-007 interim results are promising and reveal the potential of rilparencel to preserve kidney function in patients with moderate to severe CKD. Topline findings from PROACT 1 are expected in the third quarter of 2027.
