AstraZeneca and Daiichi Sankyo’s new breast cancer treatment, Datroway, has shown remarkable results in extending patient survival during a late-stage clinical trial, marking a potential breakthrough in treating triple-negative breast cancer (TNBC) — one of the most aggressive and difficult-to-treat forms of the disease.
The results were presented on Sunday at the European Society for Medical Oncology (ESMO) Congress.
Breakthrough results for Datroway
Patients treated with Datroway had a median overall survival of 23.7 months, compared with 18.7 months for those receiving chemotherapy alone. The drug also demonstrated significantly better response rates and longer periods of disease control, according to data presented at ESMO.
“This is the first time we show survival superiority of a new approach like Datroway versus standard chemotherapy,” said Abder Laadem, head of late-stage oncology clinical development at Daiichi Sankyo.
How the drug works
Datroway is an antibody-drug conjugate (ADC) — a cutting-edge class of targeted cancer medicines that act like guided missiles, delivering chemotherapy directly to tumor cells while minimizing exposure to healthy tissue.
“This targeted design ensures more precise drug delivery and lower toxicity,” said Susan Galbraith, AstraZeneca’s executive vice president of oncology R&D.
Patients on Datroway remained on therapy for twice as long as those on chemotherapy, yet rates of severe (Grade 3) side effects were similar, and treatment discontinuations were lower.
Potential competitor to Gilead’s Trodelvy
Datroway’s success positions it as a strong rival to Gilead Sciences’ Trodelvy, another ADC used to treat TNBC.
Ken Keller, Daiichi Sankyo’s global oncology head, said Datroway may have an advantage due to its convenience. “Trodelvy is given every two weeks; ours is every 21 days. Those differences matter when drugs are close,” he said.
He added that together with Enhertu — another AstraZeneca-Daiichi ADC — “we can actually treat up to 90% of all women with breast cancer. These drugs have the potential to become the standard of care.”
Trodelvy also shows promising results
At the same ESMO meeting, Gilead Sciences presented new data for Trodelvy (sacituzumab govitecan), showing it lowered the risk of disease progression by 38% compared to chemotherapy in previously untreated patients with advanced TNBC whose tumours do not express the PD-L1 protein.
The trial involved 558 patients, with those on Trodelvy showing a median progression-free survival of 9.7 months versus 6.9 months for chemotherapy. The overall survival data is still being monitored, according to Gilead.
“This could represent the first major treatment advance for this patient population in 20 years,” said Javier Cortes, head of the International Breast Cancer Center in Spain and principal investigator of the trial.
Trodelvy received its first US FDA approval in 2020 for advanced TNBC in patients who had undergone at least two prior therapies. Gilead is also studying Trodelvy in combination with Merck’s Keytruda, which earlier showed a 35% reduction in TNBC progression risk when used as an initial treatment.
About triple-negative breast cancer
Triple-negative breast cancer accounts for about 10% to 15% of all breast cancers and is known for its aggressiveness, limited treatment options, and poor prognosis. The disease tends to spread rapidly and respond poorly to hormonal or targeted therapies.
The emergence of antibody-drug conjugates such as Datroway and Trodelvy offers a significant step forward in providing patients with more effective, less toxic treatment options.
