AstraZeneca Plc and Daiichi Sankyo Co’s cancer drug Enhertu has shown strong results for early-stage breast cancer patients, results that could expand the blockbuster’s reach to thousands of people and move it closer to a potential cure.
In two pivotal trials presented over the weekend at the European Society for Medical Oncology meeting in Berlin, Enhertu outperformed Roche Holding AG’s Kadcyla in preventing disease recurrence and performed well when given before surgery. Daiichi shares rose 3.1% in Tokyo trading on Monday, helping the stock recover some of this year’s losses. It had fallen 8.2% so far before the market opened amid concerns over US tariff talks.
The findings mark an important test for Astra and Daiichi’s six-year alliance, which has already turned Enhertu into one of the world’s fastest-growing cancer drugs, generating sales of $3.75 billion last year. The drug, discovered by Daiichi, became the center of Astra’s biggest deal in more than a decade when it agreed to pay $6.9 billion to co-develop it.
“The goal here is cure, so that’s what we’re moving toward,” Daiichi U.S. Chief Executive Officer Ken Keller said, referring to Enhertu’s study before the surgery. “What we’re hearing is that Enhertu is going to become a foundational treatment for early-stage HER2-positive disease.”
Enhertu is an antibody-drug conjugate – a treatment that delivers chemotherapy directly to tumor cells while limiting damage to healthy tissue. The study focused on HER2-positive breast cancer patients, who account for about one in five cases. According to Astra, approval in early-stage disease could make the drug available to an estimated 130,000 additional patients in the Group of Eight industrialized countries.
In one study, more than 92% of patients who received Enhertu after surgery were alive and free of aggressive disease after three years, compared with 84% of those treated with Kadcyla. The drug reduced the risk of death or recurrence by 53%. Serious side effects were slightly higher on Kadcyla, although Enhertu caused more cases of interstitial lung disease, potentially serious inflammation and scarring of the lung tissue.
A separate study tested the drug before surgery. About two-thirds of patients given Enhertu had no remaining cancer in their breasts or lymph nodes at the time of surgery, compared with 56% in the standard-therapy group. Those taking Enhertu also reported less serious side effects. The researchers said data on long-term recurrence-free survival is not yet mature, but shows an early favorable trend.
question of time
The big question for doctors in Congress was whether the results meant Enhertu should be given before or after surgery. Sara A., medical oncologist at Fred Hutchinson Cancer Center. As for Hurwitz, who was not involved in either study, she is leaning toward using it after surgery, rather than after standard chemotherapy, noting that there is no data yet on how long people survive without cancer recurrence in patients who receive it before surgery.
Paul-Henri Coutu, an oncologist at the Institut Curie in Paris who was not involved in the research, said he was “not very convinced” by the data on Enhertu’s use before surgery, adding that he was not sure it would be enough for approval. Meanwhile, Enhertu’s benefits after surgery were clear, he said.
Having data from both trials is a “real strength,” Dave Frederickson, executive vice president of Astra’s oncology business, said in an interview. He said, “When the debate is over what is the best starting setting to use Enhertu, this is a good topic for the community to wrestle with.”
Disclaimer: This story is published from a wire agency feed without any modifications to the text.
