Phase 3 Data Mixed for Cell-Based Muscle Regeneration Therapy

Topline results were announced from a phase 3 study evaluating the efficacy and safety of allogeneic PLX-PAD cells for the treatment of muscle injury following arthroplasty for hip fracture.

PLX-PAD cells are placenta-derived, mesenchymal-like adherent stromal cells that are expanded ex vivo and are designed to be administered to patients without the need for tissue or genetic matching. These cells release factors in response to chemical distress signals from tissues triggering the body’s repair mechanisms and stimulate tissue renewal, differentiation and modulation of immune-mediated inflammation.

The multicenter, randomized, double-blind, placebo-controlled study (ClinicalTrials.gov Identifier: NCT03451916) included 240 patients up to 90 years of age with muscle injury following arthroplasty for hip fracture. Eligible patients were randomly assigned 1:1 to receive either an intramuscular administration of PLX-PAD cells or placebo with a follow-up period up to 52 weeks. 

Results showed that treatment with PLX-PAD did not meet the primary endpoint of improvement in Short Physical Performance Battery (SPPB) score at week 26; the SPPB is a series of physical performance tests used to assess lower extremity function and mobility.

Findings did show that patients treated with PLX-PAD experienced a statistically significant increase in Hip Abduction Strength (secondary endpoint) vs placebo. A positive trend in the 6 minute walk test was also observed at week 52 among PLX-PAD treated patients.

“We were pleased to learn that the data from this phase 3 study reinforced the data from the phase 1/2 study, with PLX-PAD demonstrating an increase in muscle strength,” said Pluristem Chief Executive Officer and President, Yaky Yanay. “While we were disappointed that this significant benefit did not translate to an SPPB score improvement, Pluristem will seek further regulatory advice to find a way to bridge the gap between the clear impact on muscle strength and the functionality score.”

Reference

Pluristem reports topline results from its phase iii study of muscle regeneration following hip fracture surgery. News release. Pluristem Therapeutics Inc. July 13, 2022. Accessed July 15, 2022. https://www.pluristem.com/wp-content/uploads/2022/07/Pluristem_Hip_Topline_results_FINAL_FOR_RELEASE_isa.pdf