Datroway pulls ahead in triple-negative breast

26 May 2026

Astra and Daiichi beat Gilead to the punch, at least in one setting.

AstraZeneca and Daiichi have prevailed in the battle to get a TROP2-directed antibody drug conjugate FDA approved in first-line triple-negative breast cancer. The FDA nod came in PD-(L)1-ineligible patients, ahead of a decision on Gilead’s Trodelvy.Still, in PD-L1-positive patients, Gilead is in the lead – and Datroway appears to have been delayed further. Meanwhile, another TROP2 player, Merck & Co and Kelun’s sacituzumab tirumotecan, has also bagged a first-line TNBC win, in a Chinese phase 3.PD-(L)1 ineligibleDatroway’s latest approval was supported by the Tropion-Breast02 trial, presented at ESMO last year. It found a 43% reduction in the risk of disease progression or death, and a 21% reduction in the risk of death, with Datroway versus chemo. Progression-free and overall survival were co-primary endpoints.Meanwhile, Trodelvy’s analogous Ascent-03 study was slightly less convincing, producing a 38% reduction in the risk of progression or death with Trodelvy versus chemo. And there was no OS benefit, although this was only a secondary endpoint, and data were immature.Trodelvy is due a US decision in the second half. Meanwhile, the EU’s CHMP gave it a positive opinion on Friday.The Gilead drug is already approved in third-line TNBC, while this is Datroway’s first TNBC approval. Around 70% of metastatic TNBC patients aren’t candidates for checkpoint inhibitor therapy, according to Astra.PD-L1 positiveHowever, in PD-L1-positive disease, it’s a different story. Trodelvy has prevailed here in Ascent-04, which compared Trodelvy plus Keytruda, versus Keytruda plus chemo, in patients with PD-L1 expression of 10% or more. Again, an FDA decision is expected in the second half.Datroway’s analogous Tropion-Breast05 study is yet to yield data. Indeed readout, which was once expected this year, has been pushed back to 2027, according to Astra's fourth-quarter results presentation in February. That trial is also treating PD-L1 ≥10% expressers, but is testing Datroway with or without Imfinzi, versus Keytruda plus chemo.Both drugs still have a lot to prove. Trodelvy sold $1.4bn in 2025, so has a long way to go to justify the $21bn Gilead spent on its originator, Immunomedics. Meanwhile Datroway, which bagged its first approval in early 2025, brought in $78m last year. Astra paid Daiichi $1bn upfront in 2020 to co-develop the asset.Sac-tmtElsewhere, sac-tmt’s latest success came in the Chinese Optitrop-Breast03 study, which enrolled PD-(L)1-positive patients who’d received checkpoint inhibitors for early-stage disease, as well as PD-L1-negatives.Kelun said the trial met its co-primary PFS endpoint at an interim analysis, showing a “statistically significant and clinically meaningful improvement” with sac-tmt versus investigator’s choice of chemo. OS, also a co-primary, is immature, but the group claimed a positive trend.Merck has made a huge investment into global trials of sac-tmt; in first-line TNBC it’s carrying out TroFuse-011, testing the ADC with or without Keytruda, but is taking a slightly different tack by enrolling PD-L1 <10% expressers. Keytruda plus chemo is the current standard of care in first-line TNBC patients with PD-L1 expression of 10% or higher.

Still, in PD-L1-positive patients, Gilead is in the lead – and Datroway appears to have been delayed further. Meanwhile, another TROP2 player, Merck & Co and Kelun’s sacituzumab tirumotecan, has also bagged a first-line TNBC win, in a Chinese phase 3.

PD-(L)1 ineligible

Datroway’s latest approval was supported by the Tropion-Breast02 trial, presented at ESMO last year. It found a 43% reduction in the risk of disease progression or death, and a 21% reduction in the risk of death, with Datroway versus chemo. Progression-free and overall survival were co-primary endpoints.

Meanwhile, Trodelvy’s analogous Ascent-03 study was slightly less convincing, producing a 38% reduction in the risk of progression or death with Trodelvy versus chemo. And there was no OS benefit, although this was only a secondary endpoint, and data were immature.

Trodelvy is due a US decision in the second half. Meanwhile, the EU’s CHMP gave it a positive opinion on Friday.

The Gilead drug is already approved in third-line TNBC, while this is Datroway’s first TNBC approval. Around 70% of metastatic TNBC patients aren’t candidates for checkpoint inhibitor therapy, according to Astra.

PD-L1 positive

However, in PD-L1-positive disease, it’s a different story. Trodelvy has prevailed here in Ascent-04, which compared Trodelvy plus Keytruda, versus Keytruda plus chemo, in patients with PD-L1 expression of 10% or more. Again, an FDA decision is expected in the second half.

Datroway’s analogous Tropion-Breast05 study is yet to yield data. Indeed readout, which was once expected this year, has been pushed back to 2027, according to Astra's fourth-quarter results presentation in February. That trial is also treating PD-L1 ≥10% expressers, but is testing Datroway with or without Imfinzi, versus Keytruda plus chemo.

Both drugs still have a lot to prove. Trodelvy sold $1.4bn in 2025, so has a long way to go to justify the $21bn Gilead spent on its originator, Immunomedics. Meanwhile Datroway, which bagged its first approval in early 2025, brought in $78m last year. Astra paid Daiichi $1bn upfront in 2020 to co-develop the asset.

Sac-tmt

Elsewhere, sac-tmt’s latest success came in the Chinese Optitrop-Breast03 study, which enrolled PD-(L)1-positive patients who’d received checkpoint inhibitors for early-stage disease, as well as PD-L1-negatives.

Kelun said the trial met its co-primary PFS endpoint at an interim analysis, showing a “statistically significant and clinically meaningful improvement” with sac-tmt versus investigator’s choice of chemo. OS, also a co-primary, is immature, but the group claimed a positive trend.

Merck has made a huge investment into global trials of sac-tmt; in first-line TNBC it’s carrying out TroFuse-011, testing the ADC with or without Keytruda, but is taking a slightly different tack by enrolling PD-L1 <10% expressers. Keytruda plus chemo is the current standard of care in first-line TNBC patients with PD-L1 expression of 10% or higher.