ProKidney stops extra CKD cell therapy phase 3 trial after FDA approval

ProKidney has decided to halt one of its phase 3 trials for the kidney disease cell therapy rilparencel, after determining it was not necessary for FDA approval. Rilparencel, also known as REACT, is an autologous cell therapy developed by identifying progenitor cells from a patient’s biopsy. These cells are then prepared for injection into the kidney, with the aim of integrating into the damaged tissue and restoring the organ's function.

The North Carolina-based biotech firm has been conducting two phase 3 trials for rilparencel targeted at Type 2 diabetes and chronic kidney disease. These are the REGEN-006 (PROACT 1) study within the United States and the REGEN-016 (PROACT 2) study in other countries. After a thorough internal and external review, which included consultations with former FDA officials and regulatory experts, ProKidney concluded that the optimal strategy for bringing rilparencel to U.S. patients involved prioritizing one of these trials.

Rilparencel was granted the FDA’s regenerative medicine advanced therapy (RMAT) designation in 2021. This designation is designed to expedite the development and review process for regenerative medicines. The review determined that the RMAT designation qualifies rilparencel for FDA approval through an expedited pathway, contingent on a successful outcome from the U.S.-focused phase 3 trial REGEN-006.

As a result, ProKidney will discontinue the REGEN-016 study, which will release between $150 million to $175 million in cash. This will help the biotech company fund its operations into early 2027. However, ProKidney might still require additional funding later, as the top-line results from the remaining phase 3 trial are not expected until the third quarter of 2027.

The company, founded by Royalty Pharma CEO Pablo Legorreta, raised $140 million through a public offering and a concurrent registered direct offering in June. This funding extended the company's financial runway into mid-2026.

CEO Bruce Culleton, M.D., elaborated on the decision, stating, “We decided to prioritize PROACT 1 to accelerate potential U.S. registration and commercial launch.” He expressed confidence that this strategic shift in their phase 3 program is the most efficient way to bring rilparencel to market in the U.S., which remains their highest priority.

Earlier this year, the phase 3 trials were put on hold while ProKidney amended the PROACT 1 protocol and upgraded its manufacturing capabilities to meet international standards. Manufacturing of rilparencel and the trials themselves resumed in the second quarter.