ProKidney's CKD Cell Therapy Shows Mixed Results in Phase 2 Trial

ProKidney, a North Carolina-based biotech company, has reported mixed results from its phase 2 trial of rilparencel, an autologous cell therapy designed to treat chronic kidney disease (CKD). The REGEN-007 trial, which evaluated the therapy in patients with diabetes and CKD, demonstrated significant improvement in kidney function for one cohort but fell short of statistical significance in another.

Promising Results in Primary Cohort

The primary cohort of the REGEN-007 trial, consisting of patients who received two rilparencel injections three months apart, showed a statistically significant and clinically meaningful improvement in kidney function. This group experienced a 78% annual improvement in their estimated glomerular filtration rate (eGFR) slope, which measures the rate of kidney function decline.

Dr. Bruce Culleton, CEO of ProKidney, expressed enthusiasm about these results, stating, "We are very encouraged by the REGEN-007 topline results that demonstrated a robust improvement in eGFR slope following treatment with rilparencel in Group 1." He further noted that 63% of patients in this group met key inclusion criteria for the ongoing phase 3 PROACT 1 study, with similar efficacy observed in this subgroup.

Secondary Cohort Falls Short of Significance

The trial's second cohort, which initially received a single rilparencel injection with a potential second dose based on sustained kidney function decline, did not achieve statistical significance. This group showed a 50% improvement in eGFR slope, which ProKidney suggested as "evidence of a dose response" despite not meeting the primary endpoint.

Implications for Ongoing Phase 3 Trial

The mixed results from the phase 2 trial have implications for ProKidney's ongoing phase 3 study, PROACT 1. The company plans to meet with the FDA this summer to discuss using eGFR slope as the surrogate endpoint in the phase 3 trial. ProKidney hopes that positive results from PROACT 1, which uses the same dosing regimen as the more successful phase 2 cohort, could pave the way for accelerated approval of rilparencel.

In September 2024, ProKidney halted an international phase 3 trial, PROACT 2, after concluding that rilparencel could be eligible for FDA approval through an expedited pathway based on PROACT 1 results alone.

Market Response and Safety Profile

Investors responded positively to the news, with ProKidney's stock price surging 48% in premarket trading following the announcement. The company also highlighted that no serious adverse events were linked to rilparencel treatment during the trial, supporting its safety profile.

As the pharmaceutical industry continues to seek innovative treatments for chronic kidney disease, ProKidney's rilparencel represents a potential breakthrough in cell therapy approaches. The coming months will be crucial as the company pursues further clinical development and regulatory discussions to advance this promising treatment option.