The newly developed Bristol-Myers (BMS) lung cancer drug Opdivo, a so-called checkpoint inhibitor that stimulates the immune system so that it can attack malignant tumours, has clearly failed to meet its mark in clinical trials, the company revealed this week. At the annual meeting of the European Society of Medical Oncology in Copenhagen, Denmark, the US drugmaker unveiled a study showing that Opdivo had proved to be inferior to chemotherapy, keeping the cancer at bay for only about four months compared with six months for the standard drug cocktail. 

BMS had warned in August that Opdivo had disappointed, but up to now had not revealed details. Earlier studies had suggested it could become a replacement for more toxic chemotherapy regimens in patients suffering from untreated lung cancer. The drug, which costs $150,000 for a full course of treatment, is said to have been more successful, however, in trials involving less common cancers such as melanoma and head and neck cancer.

The US drugmaker’s share price took another 10% tumble on the news, after the first warning reportedly shaved $23 billion of f the company’s value. News from Copenhagen was more positive for US Merck, whose flagship cancer drug Keytruda is credited, among other things, for curing former US President Jimmy Carter of melanoma and knock-on metastases.

A large, late-stage study of Keytruda, tested on patients selected because they were thought to be more likely to respond to the drug, is said to have shown that those taking it typically went for more than 10 months before their cancer worsened, compared with six months for those receiving chemotherapy. Some 45% either saw their tumors disappear entirely or shrink substantially, compared with 28% of those on chemotherapy.

Merck has filed for US Food and Drug Administration (FDA) approval of Keytruda for the indication untreated lung cancer. The US health watchdog is likely to give the green light before the end of this year, reports from Copenhagen said. Another small trial in which patients were given Keytruda in combination with simultaneous chemotherapy suggested that this combination could be more effective than either single regimen, Merck reported.

Up to now, it had been assumed that the BMS and Merck immunotherapies were identical, but experts said the companies adopted sharply different strategies for testing their drugs and that the selection of patients for the trials may have played a crucial role.