FDA Designates AML Therapy for Rare Pediatric Disease
The U.S. Food and Drug Administration has granted rare pediatric disease designation to galinpepimut-S. The designation is for the treatment of acute myeloid leukemia (AML). Such regulatory accelerations place continued pressure on CDMOs to maintain flexible and rapid-response manufacturing systems.
- Galinpepimut-S is a peptide immunotherapy that targets the Wilms Tumor 1 (WT1) antigen, a protein highly expressed in various cancers, including AML. The therapy is designed to stimulate a robust T-cell immune response (both CD4+ and CD8+) to target and eliminate cancer cells. - The therapy, licensed from Memorial Sloan Kettering Cancer Center, is currently in a Phase 3 clinical trial (REGAL study) for adult AML patients in remission after second-line therapy. An interim analysis of the trial showed a median overall survival of over 13.5 months, a favorable outcome compared to the historical median of approximately 6 months for this patient population. - The main benefit of a Rare Pediatric Disease Designation is eligibility for a Priority Review Voucher (PRV) if the drug is approved. This voucher can be used to expedite the FDA review of a different drug from six months down to ten, or it can be sold to another company; many have been sold for around $100 million. - The treatment regimen involves subcutaneous injections, similar to a traditional vaccine, administered with the immune modulator GM-CSF to enhance the immune response. The manufacturing process, which SELLAS is working to optimize into a lyophilized (freeze-dried) formulation, centers on synthetic peptide chains. - Beyond AML, galinpepimut-S has been investigated in Phase 2 trials for other cancers where the WT1 antigen is overexpressed, including malignant pleural mesothelioma, multiple myeloma, and ovarian cancer. A Phase 1/2 "basket" study has also explored its use in combination with the PD-1 inhibitor pembrolizumab in several advanced cancers. - The designation was supported by Phase 2 data in adults, which showed that younger patients (as young as 25) had significantly higher clinical benefits. This observation is attributed to the mechanism of action relying on a patient's immune system, which is generally more robust in younger individuals.
