Datopotamab deruxtecan has a second US breast cancer green light now. The FDA cleared the Daiichi Sankyo and AstraZeneca antibody-drug conjugate for adults with metastatic or unresectable triple-negative breast cancer (TNBC). The drug targets patients who cannot get PD-1 or PD-L1 inhibitor therapy.

The drug is sold as Datroway. Researchers call it Dato-DXd. The molecule is a Trop-2-directed antibody linked to a topoisomerase inhibitor payload. The drug carries lung cancer labels too. The first US breast cancer approval came in January 2025. That covered prior-treated HR-positive, HER2-negative disease.

What the new approval covers

The new indication targets metastatic or unresectable TNBC where checkpoint inhibitors are not viable. That subset has long been hard to treat. Few first-line options exist past standard chemotherapy.

The FDA decision followed priority review. The basis: data from the randomised, open-label TROPION-Breast02 trial. Findings went public at the 2025 European Society for Medical Oncology (ESMO) Congress and were published in the Annals of Oncology.

Inside the TROPION-Breast02 trial

TROPION-Breast02 enrolled 644 patients with metastatic or unresectable TNBC tumours. None had received prior chemotherapy for advanced disease. None qualified for PD-1/PD-L1 inhibitor therapy either.

Patients got randomised to datopotamab deruxtecan or to the investigator's choice chemotherapy. The primary endpoint was progression-free survival.

The numbers favoured the new antibody-drug conjugate.

• Median progression-free survival: 10.8 months on Dato-DXd vs 5.6 months on chemotherapy (HR 0.57).
• Median overall survival: 23.7 months vs 18.7 months (HR 0.79).
• Confirmed objective response rate: 64% vs 30%.

The PFS gap nearly doubled time without progression. A 5-month OS gap is the kind of signal that moves first-line care.

What the trial investigator said

Trial investigator Tiffany A. Traina, MD, spoke in a Daiichi Sankyo press release. Traina works at Memorial Sloan Kettering Cancer Centre in New York City. "Datopotamab deruxtecan is the first and only medicine to significantly prolong overall survival in the first-line setting compared to chemotherapy in patients with metastatic triple-negative breast cancer who are not candidates for immunotherapy," Traina said.

"This approval will bring a much-needed treatment option for these patients," she added.

That language is important. TNBC patients who can use immunotherapy already have options. The group that cannot use it has had fewer choices. The new label fills that gap.

How datopotamab deruxtecan is dosed

The dose is 6 mg/kg. There is a hard cap. Patients at 90 kg or more get up to 540 mg per dose.

The drug goes by IV infusion once every 3 weeks. It runs until disease progression or unacceptable toxicity.

The schedule fits standard oncology infusion clinic workflows. That should ease rollout in community cancer clinics.

Safety profile and monitoring

The prescribing information will appear on Drugs@FDA. It lists warnings for several known risks of this drug class.

• Interstitial lung disease and pneumonitis.
• Ocular adverse reactions.
• Stomatitis and oral mucositis.
• Embryo-fetal toxicity.

Each needs baseline checks and ongoing monitoring. Teams should plan lung and ocular workups. They should also counsel patients on pregnancy avoidance during treatment.

Where this fits in the TNBC market

Datopotamab deruxtecan now sits with a growing set of antibody-drug conjugates in advanced breast cancer. The drug employs topoisomerase-inhibitor warhead chemistry. That class has driven recent ADC growth. It targets Trop-2, like sacituzumab govitecan.

A first-line OS win in this TNBC group is a clear milestone. Until now, this group typically went straight to chemotherapy. The new approval offers a targeted option with better PFS and OS in the pivotal trial.

The Daiichi Sankyo and AstraZeneca tie-up remains the commercial backbone. Both firms continue to expand the drug across breast and lung cancer.

For oncology programs, the new datopotamab deruxtecan label adds a first-line option for a TNBC subset that needed one. Teams should check eligibility carefully. The label requires PD-1/PD-L1 ineligibility.

Coverage on Medigear.uk shows why oncology teams must track how datopotamab deruxtecan findings shape first-line metastatic breast cancer care.

Source: Originating coverage based on Medscape reporting by Sharon Worcester on the FDA approval of datopotamab deruxtecan (Dato-DXd, Datroway, Daiichi Sankyo) for unresectable or metastatic triple-negative breast cancer. TROPION-Breast02 trial findings published in Annals of Oncology. Quoted commentary from trial investigator Tiffany A. Traina, MD, Memorial Sloan Kettering Cancer Center, New York City.