Lung Cancer Drug Fails Another Late-Stage Trial
Testing of MAGE-A3 immunotherapy continues
A recombinant MAGE-A3 cancer immunotherapeutic developed by GlaxoSmithKline has failed to meet the first and second co-primary endpoints of a phase III study involving patients with non–small-cell lung cancer (NSCLC).
The treatment did not significantly extend disease-free survival (DFS) compared with placebo in either the overall MAGE-A3–positive population (first co-primary endpoint) or in MAGE-A3–positive patients who did not receive chemotherapy (second co-primary endpoint).
DFS was defined as the time from randomization to the date of first recurrence of the disease or death, whichever comes first.
The MAGE-A3 cancer immunotherapeutic consists of recombinant MAGE-A3 protein and a new immunostimulant, AS15 (a combination of QS-21 Stimulon adjuvant, monophosphoryl lipid A, and CpG7909, a Toll-like receptor-9 [TLR-9] agonist, in a liposomal formulation).
MAGE-A3 is a tumor-specific antigen expressed in a variety of cancers but not in normal cells. In NSCLC, it is expressed in approximately one-third of tumors in patients diagnosed with stage IB, II, or IIIA disease.
The phase III, double-blind, randomized, placebo-controlled MAGRIT (MAGE-A3 Adjuvant Non–Small-Cell LunG CanceR ImmunoTherapy) trial enrolled 2,312 MAGE-A3–positive patients in 34 countries. The study was designed to assess the efficacy of recombinant MAGE-A3 plus the AS15 antigen-specific cancer immunotherapeutic as adjuvant therapy in patients with MAGE-A3–positive NSCLC. The patients were given up to 13 intramuscular injections of either the MAGE-A3 immunotherapeutic or placebo over 27 months.
As planned, GSK will continue the study in order to assess the third co-primary endpoint. This endpoint is designed to identify a subset of MAGE-A3–positive patients that may benefit from the treatment with the MAGE-A3 cancer immunotherapeutic. Results from a final analysis are expected in 2015.
In another phase III trial (DERMA), GSK is continuing to evaluate whether a gene signature can identify a subpopulation of melanoma patients that would benefit from the same investigational MAGE-A3 cancer immunotherapeutic. The outcome is expected in 2015.
Source: GlaxoSmithKline; March 20, 2014.