The phase II trial, conducted in Germany, was an open-label study to evaluate the efficacy, safety and tolerability of HGS-ETR1 (mapatumumab) as monotherapy in patients with relapsed or refractory colorectal cancer.
The company believes the results were sufficient to warrant further evaluation of the compound in this indication.
A total of 38 patients with recurrent colorectal cancer were enrolled in the trial to receive up to six cycles of treatment in the absence of disease progression. Patients participating in the study had received up to six previous cancer treatment regimens.
Although the data showed the drug to be generally safe, one patient discontinued therapy due to an adverse event in which the possible contribution of HGS-ETR1 could not be ruled out completely. Stable disease was observed in 31.6% of the patients treated, with a median duration of 2.6 months.
“The medical need for effective new therapeutic agents continues to be significant. The results of the phase II study of HGS-ETR1 in these heavily pretreated patients with relapsed or refractory colorectal cancer, together with preclinical observations, support the continued evaluation of HGS-ETR1 in combination with chemotherapy for the treatment of colorectal cancer,” said professor Siegfried Seeber, principal investigator and director, University Clinic for Internal Medicine,University of Essen.
If the drug does enter phase III development, GlaxoSmithKline will equally share developmental costs following the company’s decision to exercise its option under a 1996 agreement to develop and commercialize HGS-ETR1 jointly with Human Genome Sciences.