Prometheus Biosciences Reports Positive Topline Phase 1 Data on Lead Therapeutic Candidate PRA023; Expands Indications to Include Systemic Sclerosis-Associated Interstitial Lung Disease (SSc-ILD)

Phase 1 trial achieved primary objective of safety and tolerability and demonstrated favorable outcomes on other key endpoints, including target engagement and immunogenicity

Discussion of Phase 1 results and rationale around SSc-ILD as new PRA023 indication to be presented in conference call scheduled today at 8:00 AM EST

SAN DIEGO, Dec. 07, 2021 (GLOBE NEWSWIRE) -- Prometheus Biosciences, Inc. (NASDAQ: RXDX), a clinical-stage biotechnology company pioneering a precision medicine approach for the discovery, development and commercialization of novel therapeutic and companion diagnostic products for the treatment of immune-mediated diseases, today reported positive topline results from its Phase 1 trial of PRA023 in healthy volunteers. It also announced that it is broadening its pipeline by adding a third indication for PRA023, Systemic Sclerosis-associated Interstitial Lung Disease (SSc-ILD), with the initiation of a Phase 2 clinical trial anticipated for the first quarter of 2022.

“Our design objective for PRA023 was to develop a competitive anti-TL1A antibody,” said Mark McKenna, CEO and Chairman of Prometheus Biosciences. “Our Phase 1 data suggest that we have exceeded that objective, and we strongly believe that PRA023 has the potential to be a best-in-class TL1A inhibitor to address immune-mediated diseases.”

The Phase 1 trial was a double-blind, placebo-controlled study which enrolled 69 healthy volunteers with 6 cohorts of subjects in the single ascending dose (SAD) phase and 3 cohorts of subjects in the multiple ascending dose (MAD) phase. The primary outcome measure was safety and tolerability over 14 weeks in the SAD and 18 weeks in the MAD. PRA023 was well-tolerated, with no safety signal identified during the study. There were no infusion reactions nor drug-related extension in infusion time, at doses of up to 1000 mg delivered intravenously over 30 minutes.

One of the secondary outcomes for the trial was the rate of immunogenicity associated with PRA023 after single and multiple doses, measured up to 14 and 18 weeks. Data demonstrated that < 20% of participants who received clinically relevant doses of PRA023 (1,000 mg for SAD cohort and 200 mg to 500 mg for MAD cohort) developed anti-drug antibodies (ADAs) through the prolonged follow up period. Immunogenicity had no apparent impact on safety outcomes, pharmacokinetics parameters, and pharmacodynamic (PD) parameter.