A new drug from Bristol-Myers Squibb that turns the body into a weapon against cancer failed to beat chemotherapy in a large head-to-head clinical trial, marking the biggest setback for the hot new field of immunotherapy.

Opdivo, a type of immunotherapy known as a checkpoint inhibitor, had been tipped as a replacement for chemotherapy for patients suffering from advanced lung cancer, but a study published on Sunday showed the new medicine is inferior to the established treatment.

Those taking Opdivo typically survived for just over four months before the disease worsened, whereas those who received chemotherapy went for six months before the cancer progressed, according to the trial of 541 patients.

Opdivo is already approved for non small-cell lung cancer patients who have tried chemotherapy, but Bristol-Myers had hoped the medicine would usurp the poisonous cocktail to become the first drug of choice for oncologists treating newly-diagnosed patients.

“We thought Opdivo could beat chemotherapy, and we have answered the question: for the broad population it is not enough,” said Fouad Namouni, oncology development head at Bristol-Myers.

Hopeful

Mr Namouni said he was hopeful that adding Opdivo to an older Bristol-Myers immunotherapy, Yervoy, would be more effective than chemotherapy, but a large study testing that combination is not expected to be completed until 2018.

Lung cancer is the most common and deadliest form of the disease, with 535,000 patients diagnosed each year in Europe and the US, and roughly 85 per cent of cases involve non small-cell tumours.

By the time most patients are diagnosed, they are already suffering from advanced disease, and roughly 95 per cent die within five years.

Bristol-Myers first warned its drug had flunked the trial in August, prompting investors to wipe more than $23 billion off the value of the US pharmaceuticals group – but it did not reveal the full scale of the failure until Sunday.

The company published the study at the annual meeting of the European Society of Medical Oncology in Copenhagen, where oncologists gathered to pore over research from pharmaceutical companies and academic institutions.

Delegates at the meeting heard more positive news from Merck, another US drugmaker that has been engaged in a two-horse race with Bristol-Myers to develop checkpoint inhibitors, which work by removing brakes on the immune system so it can attack cancer.

Merck published a large, late-stage study of its drug, Keytruda, which it tested in a group of patients who were selected for the trial because they were thought to be more likely to respond to the drug.

These patients had tumours with very high levels of a substance known as PD-L1, a characteristic shared by somewhere between 25 and 30 per cent of all people suffering from non small-cell lung cancer.

In Merck’s trial, patients taking Keytruda typically went for more than 10 months before their cancer worsened, compared with six months for those receiving chemotherapy.

About 45 per cent of patients either saw their tumours disappear entirely or shrink substantially, compared with 28 per cent on chemotherapy.

FDA approval

Merck has submitted Keytruda for approval in untreated lung cancer patients, and the US Food and Drug Administration is expected to give the drug the green light at the end of December.

The success of Merck’s trial is a vindication of the company’s embrace of an emerging field of science known as precision medicine, where drugs are targeted at smaller subgroups of patients who are most likely to benefit.

Conversely, Bristol-Myers tested Opdivo in a wider pool of patients, a strategy which would have resulted in higher prescriptions and drug sales had the trial been successful.

Merck published another small trial in which patients were given Keytruda and chemotherapy simultaneously, which suggested that this combination could be more effective than either single regimen.

In the study of 123 people, patients who took both drugs at the same time went for 13 months without their cancer getting worse, with 55 per cent of them experiencing a remission or substantial tumour shrinkage, compared with 29 per cent for chemotherapy alone.

Dr Roger Perlmutter, Merck’s top scientist, said the findings from both studies showed that immunotherapies were “becoming foundational in the way that we treat cancer”. – (Copyright The Financial Times Limited 2016)