Amgen Inc said its experimental drug to treat a deadly form of skin cancer shrank tumours, but did not significantly improve overall survival rates in patients enrolled in a late-stage study.
The most common serious adverse events observed in the trial include disease progression, a bacterial skin infection and fever, the company said.
Amgen said in June that data from the pivotal study showed that the drug improved survival by 21 per cent for patients with advanced forms of melanoma compared with a standard white blood cell-boosting drug.
The company first reported in March last year that the drug, talimogene laherparepvec, met the study's main goal of inducing a durable response rate (DRR) - defined as a complete or partial tumour shrinkage lasting at least six months - in 16 per cent of patients.
The company's shares were little changed at $123.87 in early trade on the Nasdaq on Friday. They closed at $124.13 on Thursday.