By Mrinalika Roy
(Reuters) -AstraZeneca and Daiichi Sankyo’s drug Enhertu has shown strong results in two pivotal studies in the early stage of a certain type of breast cancer, according to data announced on Saturday.
The findings from both trials, presented at the European Society for Medical Oncology Congress, indicate that the drug, currently used for advanced stages of certain cancers, could advance toward curative treatment.
In one late-stage study, Enhertu cut the risk of invasive disease recurrence or death by 53% compared with Roche’s Kadcyla, in patients with high-risk early HER2-positive breast cancer that persisted after surgery and initial therapy.
Three years after treatment, 92.4% of patients on Enhertu were alive and disease-free, versus 83.7% on Kadcyla.
Enhertu belongs to a class of medicines called antibody-drug conjugates (ADC), also known as “guided missiles”, for its ability to target cancer cells specifically, while sparing healthy cells, unlike conventional chemotherapy.
HER2-positive breast cancer accounts for about 15% to 20% of all breast cancers.
In a second study, patients treated with Enhertu before surgery achieved a 67.3% pathologic complete response rate, compared with 56% for standard chemotherapy and experienced fewer severe side effects.
For AstraZeneca, the results not only strengthen Enhertu’s commercial potential but also validate its broader ADC strategy.
“This vision we have for antibody drug conjugates to displace chemotherapy in multiple different settings is demonstrated,” said Susan Galbraith, AstraZeneca’s executive vice president of oncology R&D.
The sentiment was echoed by Ken Keller, global oncology head at Daiichi Sankyo – “Any place where chemotherapy is active, we ask whether our DXd ADCs can do more. That will guide our choices.”
The companies are now advancing a broad regulatory program for Enhertu, and Keller believes the biggest constraint will be the time it takes to get regulatory approval.
“I am not worried about the adoption”, Keller said, adding that the focus should be on ensuring countries can afford and reimburse the cost of the drug.
Combined sales of Enhertu by both companies reached $3.75 billion last year. It is currently approved in more than 75 countries for several types of cancers, including specific types of breast, non-small cell lung and gastric cancers.
(Reporting by Mrinalika Roy in Bengaluru; Editing by Vijay Kishore)
