ALX Oncology Reports Positive Phase 1 Results for Evorpacept with Standard Treatment in B-cell Non-Hodgkin Lymphoma

ALX Oncology Holdings Inc., a clinical-stage biotechnology company, has shared promising data from a Phase 1/2 trial of its leading compound, evorpacept. This investigational CD47-blocker is being tested in combination with rituximab and lenalidomide (R2) in patients suffering from relapsed or refractory B-cell non-Hodgkin lymphoma (R/R B-NHL). The trial results will be formally presented at the American Association for Cancer Research (AACR) Annual Meeting 2025 in Chicago.

The trial, led by Dr. Paolo Strati from the University of Texas MD Anderson Cancer Center, explores the potential of evorpacept to enhance the efficacy of current standard treatments. Dr. Strati highlights that certain pro-tumoral macrophages increase in patients with indolent B-NHL, potentially leading to resistance against frontline treatments like R2. Evorpacept is designed to activate the immune system and engage macrophages, potentially improving therapeutic outcomes in conjunction with anti-cancer antibodies such as rituximab.

In the study, 20 patients with either indolent (18 patients) or aggressive (2 patients) R/R B-NHL were enrolled. All participants had previously undergone treatment with an anti-CD20 monoclonal antibody, and a significant majority had received prior chemoimmunotherapy or experienced disease progression within two years of initial treatment. The trial tested two dosages of evorpacept: 30 mg/kg biweekly and 60 mg/kg every four weeks, both alongside the R2 regimen. The combination was well-tolerated, with no severe side effects at the administered doses.

The trial's follow-up, averaging 28 months, revealed a two-year progression-free survival rate of 69% and an overall survival rate of 84%. Importantly, 80% of patients achieved complete responses, and the overall response rate was 90%. For those with indolent NHL, the complete response rate was notably high at 83%, a significant improvement compared to the historical 34% response rate with R2 alone. Furthermore, the treatment led to an increase in T cells and anti-tumoral macrophages.

Jason Lettmann, CEO of ALX Oncology, emphasized the potential of evorpacept to significantly enhance responses to established cancer therapies. He pointed out the importance of this trial in addressing unmet needs in cancer treatment and expressed optimism for the continued investigation of evorpacept, particularly in patients with untreated indolent NHL.

The Phase 2 segment of this ongoing trial has successfully enrolled patients and aims to further evaluate the effectiveness of evorpacept in this context. The final results from the Phase 1 part of the trial underscore evorpacept's potential as a robust adjunct to existing cancer therapies, promising a new avenue for improving patient outcomes in B-NHL.

Details about the trial and its findings will be made available in a poster presentation by Dr. Strati at the AACR 2025 Annual Meeting. The presentation will provide more insights into the clinical implications of these findings, offering hope for enhanced treatment strategies in B-cell non-Hodgkin lymphoma.