Amgen says ‘breakthrough’ drug improves lung cancer survival rate by 58 per cent

Combining the Amgen drug Imdelltra with AstraZeneca’s immunotherapy Imfinzi reduces the risk of death by 58 per cent compared to using the Astra drug alone in patients with extensive-stage small cell lung cancer, according to data presented at a major medical conference on Saturday.

Imfinzi is currently the standard of care following chemotherapy for patients suffering from the aggressive and hard-to-treat disease, whose cancer does not progress after initial treatment.

The study showed that patients given both therapies had a median survival of 21.1 months, compared with 12.7 months for those treated with Imfinzi on its own.

“If you give Imdelltra earlier and earlier, you get bigger clinical benefit,” said Dr Paul Burton, chief medical officer at California-based Amgen.

The results are “unprecedented in advancing the treatment of extensive-stage small cell lung cancer”, he said.

Imdelltra’s US list price is about $30,000 per cycle, or over $390,000 a year (about £292,000).

Wall Street analysts have estimated annual sales reaching more than $2.5 billion (£1.87 billion) by 2030, according to LSEG data.

The Amgen drug is currently approved for adults in the advanced stages of small cell lung cancer that has worsened despite chemotherapy, based on data showing that Imdelltra reduced the risk of death by 40 per cent.

Full results of the 563-patient trial were presented at the European Society for Medical Oncology meeting in Madrid and published in the New England Journal of Medicine. Amgen had previously announced that the Phase 3 study was successful.

Imdelltra belongs to a dual-target class of drugs called bispecific antibodies, which are designed to pull immune system T cells into contact with cancer cells to destroy them.

Imfinzi is an older type of immunotherapy that essentially blocks the mechanism tumors use to hide from immune-system assault.

Most lung cancer cases are non-small cell, while up to 15 per cent are the small cell variety targeted by Imdelltra. About 250,000 new cases are diagnosed worldwide each year, according to the US National Institutes of Health.

Very few people diagnosed with small-cell lung cancer are candidates for surgery, and most are initially given radiotherapy and chemotherapy, Dr Burton said.

Survival rates depend on when the cancer is diagnosed, but the overall five-year rate is only around nine per cent, according to the American Cancer Society.

Amgen said that nearly 80 per cent of trial patients treated with the combination were alive after one year, compared with 53 per cent of those on Imfinzi alone, as patient follow-up continues.

Serious side effects, including low white blood cell counts, occurred in 20.9 per cent of patients on the dual therapy and 10.8 per cent with the single therapy. A potentially dangerous condition known as cytokine release syndrome, an aggressive inflammatory response, was reported in 49.6 per cent of patients who received Imdelltra. But only one case was serious and there were no CRS-related deaths.

Adverse events led to discontinuation of the combination therapy in 5.7 per cent of trial patients and 5.8 per cent of patients given only Imfinzi.