High-dose interferon alfa-2b significantly prolongs relapse-free and overall survival compared with the GM2-KLH/QS-21 vaccine in patients with resected stage IIB-III melanoma: results of intergroup trial E1694/S9512/C509801

J Clin Oncol. 2001 May 1;19(9):2370-80. doi: 10.1200/JCO.2001.19.9.2370.

Abstract

Purpose: Vaccine alternatives to high-dose interferon alfa-2b therapy (HDI), the current standard adjuvant therapy for high-risk melanoma, are of interest because of toxicity associated with HDI. The GM2 ganglioside is a well-defined melanoma antigen, and anti-GM2 antibodies have been associated with improved prognosis. We conducted a prospective, randomized, intergroup trial to evaluate the efficacy of HDI for 1 year versus vaccination with GM2 conjugated to keyhole limpet hemocyanin and administered with QS-21 (GMK) for 96 weeks (weekly x 4 then every 12 weeks x 8).

Patients and methods: Eligible patients had resected stage IIB/III melanoma. Patients were stratified by sex and number of positive nodes. Primary end points were relapse-free survival (RFS) and overall survival (OS).

Results: Eight hundred eighty patients were randomized (440 per treatment group); 774 patients were eligible for efficacy analysis. The trial was closed after interim analysis indicated inferiority of GMK compared with HDI. For eligible patients, HDI provided a statistically significant RFS benefit (hazard ratio [HR] = 1.47, P = .0015) and OS benefit (HR = 1.52, P = .009) for GMK versus HDI. Similar benefit was observed in the intent-to-treat analysis (RFS HR = 1.49; OS HR = 1.38). HDI was associated with a treatment benefit in all subsets of patients with zero to > or = four positive nodes, but the greatest benefit was observed in the node-negative subset (RFS HR = 2.07; OS HR = 2.71 [eligible population]). Antibody responses to GM2 (ie, titers > or = 1:80) at days 29, 85, 365, and 720 were associated with a trend toward improved RFS and OS (P2 = .068 at day 29).

Conclusion: This trial demonstrated a significant treatment benefit of HDI versus GMK in terms of RFS and OS in melanoma patients at high risk of recurrence.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Aged
  • Cancer Vaccines / immunology*
  • Disease-Free Survival
  • Female
  • G(M2) Ganglioside / immunology*
  • Hemocyanins / immunology
  • Humans
  • Immunoglobulin G / blood
  • Immunoglobulin M / blood
  • Interferon alpha-2
  • Interferon-alpha / adverse effects
  • Interferon-alpha / therapeutic use*
  • Male
  • Melanoma / drug therapy*
  • Melanoma / metabolism
  • Melanoma / pathology
  • Middle Aged
  • Neoplasm Staging
  • Prospective Studies
  • Recombinant Proteins
  • Saponins
  • Vaccination
  • Vaccines, Conjugate / immunology

Substances

  • Cancer Vaccines
  • Immunoglobulin G
  • Immunoglobulin M
  • Interferon alpha-2
  • Interferon-alpha
  • Recombinant Proteins
  • Saponins
  • Vaccines, Conjugate
  • G(M2) Ganglioside
  • saponin QA-21V1
  • Hemocyanins
  • keyhole-limpet hemocyanin