Novel Treatment Gains Accelerated Approval for Relapsed/Refractory Neuroblastoma

The Food and Drug Administration (FDA) has granted accelerated approval to Danyelza® (naxitamab-gqgk; Y-mAbs Therapeutics, Inc) in combination with granulocyte-macrophage colony-stimulating factor (GM-CSF) for patients 1 year of age and older with relapsed or refractory high-risk neuroblastoma in the bone or bone marrow who have demonstrated a partial response, minor response, or stable disease to prior therapy.

Naxitamab-gqgk is a humanized, monoclonal antibody that targets the ganglioside GD2, which is overexpressed on neuroblastoma cells and other cells of neuroectodermal origin, including the CNS and peripheral nerves.

The approval was based on results from two phase 2 single-arm, open-label trials (Study 201 and Study 12-230) in patients with relapsed or refractory disease high-risk neuroblastoma in the bone or bone marrow. Patients received naxitamab-gqgk 3mg/kg administered as an intravenous infusion on days 1, 3, and 5 of each 4-week cycle in combination with GM-CSF subcutaneously. At the investigator’s discretion, patients were permitted to receive pre-planned radiation to the primary disease site in Study 201 and radiation therapy to non-target bony lesions or soft tissue disease in Study 12-230.

The main efficacy outcome measures were confirmed overall response rate (ORR) per the revised International Neuroblastoma Response Criteria (INRC) and duration of response (DOR).

Among 22 patients treated in Study 201, the ORR was 45% (95% CI: 24%, 68%), and 30% of responders had a DOR greater or equal to 6 months. Among 38 patients treated in Study 12-230, the ORR was 34% (95% CI: 20%, 51%) with 23% of patients having a DOR greater or equal to 6 months. For both trials, responses were observed in either the bone, bone marrow or both. As part of the accelerated approval regulation, Study 201 will continue as a postmarketing clinical trial to verify and further characterize the clinical benefits of naxitamab-gqgk.

As for safety, the most common Grade 3 or 4 laboratory abnormalities (greater than or equal to 5% in either trial) were decreased lymphocytes, decreased neutrophils, decreased hemoglobin, decreased platelet count, decreased potassium, increased ALT, decreased glucose, decreased calcium, decreased albumin, decreased sodium and decreased phosphate. The most common adverse reactions (incidence greater than or equal to 25%) were infusion-related reactions, pain, tachycardia, vomiting, cough, nausea, diarrhea, decreased appetite, hypertension, fatigue, erythema multiforme, peripheral neuropathy, urticaria, pyrexia, headache, injection site reaction, edema, anxiety, localized edema, and irritability.

Moreover, Danyelza carries a Boxed Warning  for serious infusion-related reactions and neurotoxicity, including severe neuropathic pain, transverse myelitis and reversible posterior leukoencephalopathy syndrome.

Danyelza will be available as 40mg of naxitamab-gqgk in 10mLsingle-dose vials and is expected to be available in the coming weeks.

For more information visit ymabs.com.

References

1. FDA grants accelerated approval to naxitamab for high-risk neuroblastoma in bone or bone marrow. [press release]. Silver Spring, MD: US Food and Drug Administration; November 25, 2020. 
2. FDA approves Y-mAbs’ Danyelza® (naxitamab-gqgk) for the treatment of neuroblastoma. [press release]. New York, NY: Y-mAbs Therapeutics; November 25, 2020.
3. Danyelza®  [package insert]. New York, NY: Y-mAbs Therapeutics; 2020.