Adding chloroquine to conventional treatment for glioblastoma multiforme: a randomized, double-blind, placebo-controlled trial

Background: Malignant cell clones resistant to chemotherapy and radiotherapy frequently lead to treatment failure in patients with glioblastoma multiforme. Preliminary studies suggest that adding chloroquine to conventional therapy may improve treatment outcomes.

Objective: To examine the effect of adding chloroquine to conventional therapy for glioblastoma multiforme.

Design: Randomized, double-blind, placebo-controlled trial.

Setting: National Institute of Neurology and Neurosurgery of Mexico.

Patients: 30 patients with surgically confirmed glioblastoma confined to 1 cerebral hemisphere, with a Karnofsky performance score greater than 70, no comorbid disease, and age younger than 60 years.

Interventions: Oral chloroquine at 150 mg/d for 12 months beginning on postoperative day 5 or placebo. All patients received conventional chemotherapy and radiotherapy.

Measurements: Primary outcome was survival after surgery; surviving patients were followed up to October 2005. Periodic evaluation using the Karnofsky scale and imaging studies, as well as hematologic tests and ophthalmologic examinations, was done in all patients.

Results: Median survival after surgery was 24 months for chloroquine-treated patients and 11 months for controls. At the end of the observation period, 6 patients treated with chloroquine had survived 59, 45, 30, 27, 27, and 20 months, respectively; 3 patients from the control group had survived 32, 25, and 22 months, respectively. Although not statistically significantly different, the rate of death with time was approximately half as large in patients receiving chloroquine as in patients receiving placebo (hazard ratio, 0.52 [95% CI, 0.21 to 1.26]; P = 0.139).

Limitations: The observed advantage of chloroquine may be due to chance; differences in pretreatment characteristics and conventional treatment regimens could not be adjusted for because of the small sample size.

Conclusions: Chloroquine may improve mid-term survival when given in addition to conventional therapy for glioblastoma multiforme. These results suggest that larger, more definitive studies of chloroquine as adjuvant therapy for glioblastoma are warranted.