AstraZeneca, Daiichi beat Gilead to first-line TNBC with FDA nod for Datroway

 The TROP2 battle in first-line triple-negative breast cancer has officially kicked off.

Friday, Daiichi Sankyo and AstraZeneca announced that the FDA has approved their Datroway to treat TNBC patients who are not candidates for PD-1/L1 inhibitors. 

The two companies were quick to point out in their May 22 releases that Datroway is currently the only TROP2-directed antibody-drug conjugate (ADC) to prolong overall survival in this treatment setting versus chemotherapy.

Datroway reduced the risk of death versus chemo by 21% in the phase 3 Tropion-Breast02 study. The drug extended the median overall survival by five months to 23.7 months.

When the data were presented in October at the 2025 European Society for Medical Oncology (ESMO) Congress, Gilead Sciences’ Ascent-03 study for its rival TROP2 ADC, Trodelvy, did not meet statistical significance on overall survival in a similar first-line TNBC setting among patients who are not eligible for anti-PD-1/L1 treatments. Ascent-03 allows crossover to Trodelvy in the control arm upon disease progression, and it remains ongoing. 

Datroway’s progression-free survival improvement, at 43%, was also numerically higher than Trodelvy’s 38% by cross-trial comparison, which can be unreliable because of differences in underlying patient characteristics and trial designs. 

Gilead is likely not far behind Daiichi and AZ. In addition to Ascent-03, Trodelvy also boasts a positive readout from Ascent-04 for Trodelvy in combination with Merck & Co.’s Keytruda in first-line PD-L1-positive TNBC. Gilead has submitted both indications to the FDA with a decision expected in the second half of 2026. Investigators will share data about progression on second-line therapy for both trials at the upcoming American Society of Clinical Oncology 2026 annual meeting.

Seven out of 10 patients with metastatic TNBC are not candidates for immunotherapy, Arlene Brothers, executive director of the Triple Negative Breast Cancer Foundation, said in AZ and Daiichi’s May 22 releases. “Today’s approval of Datroway means that for the first time, these patients will have a new standard of care beyond traditional chemotherapy at the outset of their treatment.”

While AZ and Daiichi are counting on Datroway’s unique overall survival win and a halo effect from its sister med Enhertu in HER2-positive breast cancer to gain an edge, Gilead hopes its two positive trials together covering patients regardless of PD-L1 expressions, plus doctors’ familiarity with Trodelvy in second-line TNBC, will drive physician preference.

Before Friday’s FDA nod, both Datroway and Trodelvy had been added to National Comprehensive Cancer Network (NCCN) guidelines with the highest category 1 preferred regimen recommendations in first-line TNBC. 

Following the inclusion, Gilead has already seen some Trodelvy uptake in the first-line setting, Chief Commercial Officer Johanna Mercier said on the company’s first-quarter earnings call in early May. 

Meanwhile, a third TROP2 ADC, Kelun-Biotech’s Merck-partnered sacituzumab tirumotecan (sac-TMT) just reported a positive phase 3 readout in China in first-line TNBC. The drug’s OpTiTROP-Breast03 study enrolled PD-L1-negative patients, as well as those with PD-L1-positive expression who have relapsed after prior anti-PD-1/L1 treatment in early-stage disease. 

Playing catch-up to Datroway and Trodelvy with potential for differentiation, Merck’s global phase 3 TroFuse-011 study is testing sac-TMT both as a monotherapy and in combination with Keytruda in PD-L1-negative TNBC. 

The updated NCCN guideline and Datroway’s approval here could pose some complications for the recruitment of that study in the U.S., as patients in the control arm will be treated with chemotherapy.What’s more, Datroway’s latest application was reviewed under Project Orbis, which facilitates concurrent submission and review among international regulators. As part of that initiative, Datroway’s case is also being evaluated in Australia, Canada, Singapore and Switzerland. Additional reviews are also underway in the European Union, China and Japan. 

https://www.fiercepharma.com/pharma/astrazeneca-daiichi-beat-gilead-first-line-tnbc-fda-nod-datroway