Successful Multifold Dose Escalation of Anti-GD2 Monoclonal Antibody 3F8 in Patients With Neuroblastoma: A Phase I Study

Abstract

Purpose: Pain can hinder immunotherapy with anti-G_D2 monoclonal antibodies (MoAbs) like 3F8. Heat-modified 3F8 (HM3F8) lacks effector functions and could mask G_D2 or cross-reactive epitopes on nerves, thereby preventing a subsequent dose of unmodified 3F8 from activating pain fibers. We hypothesized that 3F8 dose escalation is possible without increased analgesic requirements in patients pretreated with HM3F8. Patients and Methods: Thirty patients with resistant neuroblastoma (NB) received one to two cycles of 3F8 plus granulocyte-macrophage colony-stimulating factor. 3F8 dosing began at 20 mg/m²/d and increased by 20 mg/m²/d in the absence of dose-limiting toxicity (DLT). Premedication included analgesics, antihistamines, and 5-minute infusions of HM3F8. On the basis of experience with 3F8 10 mg/m²/d in prior protocols, the DLT of pain was defined as more than seven doses of opioids administered within 2 hours. Opioid use was compared with a contemporary control group treated with 3F8 20 mg/m²/d but no HM3F8. Disease response was assessed. Results: Treatment was administered in the outpatient setting. Dose escalation stopped at 160 mg/m²/d because of drug supply limitations; even through this dosage level, analgesic requirements were similar to historical controls, and there were no DLTs. Analgesic requirements at 3F8 dosage levels through 80 mg/m²/d were significantly less compared with controls. Anti-NB activity occurred at all dosages. Conclusion: Multifold dose escalation of 3F8 is feasible. The findings can be interpreted as compatible with the possibility that HM3F8 can modify toxicity without blunting anti-NB activity. This pain control strategy may help achieve dose escalation with other anti-G_D2 MoAbs.