ProKidney (PROK) Study Update summary

Study background and rationale

• Rilparencel (REACT) is an autologous cell therapy aimed at preserving kidney function in advanced CKD patients, particularly those with diabetes facing limited options beyond dialysis or transplantation.

• Chronic kidney disease affects over three million Americans with type 2 diabetes and advanced CKD, with over 135,000 progressing to dialysis annually.

• Current therapies, including SGLT2 inhibitors, do not provide long-term preservation of kidney function, with patients typically losing 4–7 eGFR in 18 months, highlighting a significant unmet need.

• Rilparencel is positioned to address high-risk CKD patients, a group underserved by recent advances in small molecules and biologics.

• The therapy involves harvesting and expanding a patient’s kidney cells, then injecting them into both kidneys using a percutaneous approach.

Study design and patient population

• REGEN-007 is a phase II study enrolling diabetic CKD patients, randomized into two groups with different dosing regimens; 53 subjects enrolled, 27 randomized to Group 1, 24 received at least one injection, and 13 had 12 months follow-up after two injections.

• Group 1 dosing regimen mirrors the phase III protocol, with key entry criteria including CKD with diabetes, eGFR 20–50, and HbA1c <10%.

• Baseline characteristics for the 13 subjects with 12 months follow-up: mean age 62.8, 54% female, mean eGFR 29.7, and 69% on ACE/ARB therapy.

• Group 2 included 25 patients, with re-dosing triggered by sustained decline in eGFR or increase in UACR; 12 of 25 received a second injection.

• No within-study control arm; efficacy contextualized using matched controls from landmark CKD trials and a validated kidney failure risk equation.

Interim efficacy and safety results

• In Group 1, 13 subjects completed at least 12 months follow-up after the second injection; average eGFR change at 18 months was -1.3 ml/min/1.73m², compared to -6.2 ml/min/1.73m² in matched controls.

• In the phase III-eligible subgroup (n=10), average eGFR change at 18 months was -0.6 ml/min/1.73m², similar to normal aging.

• All subjects (n=24) and all phase III-eligible subjects (n=20) demonstrated similar stabilization trends in eGFR over 18 months.

• No rilparencel-related serious adverse events were observed; adverse events related to biopsy or injection were infrequent and consistent with prior studies.

• Safety profile of bilateral dosing with cryopreserved product was comparable to kidney biopsy.