AstraZeneca, Daiichi niche drug shows promise beyond breast cancer

(Reuters) - AstraZeneca and Daiichi Sankyo’s Enhertu helped patients with three different types of cancer live longer in trials, pointing to potential broader use of the breast cancer treatment.

Positive data from different trials for advanced gastric, colorectal and lung cancers presented at the virtual American Society of Clinical Oncology (ASCO) conference this week showed Enhertu’s effectiveness in patients with mutations in the HER2 gene, AstraZeneca said on Friday.

Response rate, or the number of patients that experience a reduction in cancer cells, was 42.9% for Enhertu in patients with HER2-positive metastatic gastric cancer who had taken two or more prior treatments, compared to 12.5% with standard regimens.

The drug also cut the risk of death by 41% in these patients, data from the “DESTINY-Gastric01” trial showed.

Drugmakers are increasingly using biomarker-driven drugs to treat patients with rare tumours, and AstraZeneca made a $7-billion bet on the treatment when it partnered with Japan’s Daiichi last year to work on the drug in a direct challenge to Roche.

The breast cancer drug was also successful in reducing the size of tumours by 45.3% in patients with HER2-positive advanced colorectal cancer who had tried at least two prior therapies, latest data from another trial showed. 

Though Enhertu targets the HER2 protein typical of certain breast cancers, the new data underscores its potential for expanded use and may add to AstraZeneca’s sales, albeit in smaller numbers for a niche market.

The treatment, approved only late last year, brought in $14 million in sales for the British drugmaker in the first quarter.

Enhertu also helped reduce the size of tumours in 61.9% patients in a study in patients with a type of rare lung cancer that had relapsed and spread beyond the lungs.