Y-mAbs Therapeutics' investigational antibody therapy naxitamab has demonstrated significant efficacy in treating patients with relapsed or refractory high-risk neuroblastoma, according to interim results from a Phase 2 clinical trial published in Nature Communications.
The study, which evaluated naxitamab in combination with granulocyte-macrophage colony-stimulating factor (GM-CSF), achieved its primary endpoint with an overall response rate of 50%. Among the treated patients, 38% achieved complete response (CR) and 12% showed partial response (PR).
Strong Response in Bone Disease
Particularly encouraging results were observed in patients with bone involvement, with 58% of patients showing bone compartment response. Even more impressive was the 74% response rate in the bone marrow compartment, suggesting particular efficacy in treating disease at these sites.
Efficacy in Previously Treated Patients
The trial demonstrated effectiveness across different patient populations. Of the study's responders, 58% had refractory disease, while 42% had relapsed disease. Notably, among 13 patients who had previously received anti-GD2 monoclonal antibody therapy, 4 showed response to naxitamab treatment, indicating potential benefit even in previously treated patients.
Survival Outcomes
The study reported promising survival metrics, with a one-year overall survival rate of 93%. The progression-free survival rate at one year was 35%. These results are particularly significant given the challenging nature of relapsed and refractory high-risk neuroblastoma.
Statistical Significance
The trial met its statistical threshold for efficacy, with the 95% confidence interval lower limit for overall response rate exceeding the predetermined 20% mark. This statistical validation strengthens the evidence supporting naxitamab's therapeutic potential in this difficult-to-treat patient population.
The findings represent a potentially important advancement in the treatment landscape for high-risk neuroblastoma, particularly for patients who have exhausted other treatment options or experienced disease progression after standard therapies.
