Sacituzumab tirumotecan (sac-TMT) by Merck & Co.: status and timeline

Sacituzumab tirumotecan (sac-TMT)

Make a TROP2 drug conjugate the chemotherapy replacement that pairs with Keytruda across lung, breast, endometrial and other cancers, giving Merck its next oncology backbone.

PilotStage 3 of 5

First global phase 3 win (endometrial, May 2026); 17 phase 3 trials; several approvals in China.

Updated 29 May 2026Checked 11 Oct0 updates this week

Milestones

Next · Full TroFuse-005 data and global filings

Merck licenses rights outside Greater China from KelunMay 2022Complete.
China: first approval (Kelun-Biotech)DoneComplete.
China: EGFR-mutant lung cancer, first TROP2 conjugate approved in lungMar 2025Complete.
TroFuse-005 (endometrial) meets survival and progression endpoints18 May 2026Complete.
Full TroFuse-005 data and global filingsTarget 2026Current milestone.

Most important updates

Upcoming

2026Full TroFuse-005 data and global filings (next)

Current obstacles

China data vs global trialsThe striking lung result came from a Kelun trial in China without a Keytruda-chemo control; global trials must confirm it.
Three TROP2 rivalsDatroway and Gilead's Trodelvy target TROP2 too, and PD-1 x VEGF bispecifics compete for first-line lung.

Physics limits

TROP2 is also on healthy tissueSkin and mucous membranes carry TROP2, so mouth sores, rash and blood-count drops come with the target and cap the dose.
Payload resistanceAll current TROP2 conjugates use topoisomerase I poisons; tumours that pump the drug out or repair the damage escape the whole class.

How it works

4 parts

Target

TROP2 on the tumour surface

The antibody binds TROP2, a protein found on most epithelial cancers such as lung, breast and endometrial.

Payload

Belotecan-derived poison

Carries a topoisomerase I inhibitor derived from belotecan that breaks DNA as cancer cells divide.

Linker

Built to hold in blood

A bifunctional linker is designed to keep the payload attached in circulation and release it at the tumour.

Combination

Partnered with Keytruda

Dying tumour cells may prime the immune system, so many trials add Keytruda instead of chemotherapy.

Spec sheet

Spec	Sacituzumab tirumotecan (sac-TMT)
Global phase 3 trials	17^R (reported)
Patients in phase 3 program	15,000+^R (reported)
TroFuse-005 patients	776^R (reported)
Dose (TroFuse-005)	4 mg/kg every 2 weeks^R (reported)
China lung trial with Keytruda: PFS	65% lower risk vs Keytruda alone^R (reported)

^R reported by the company

Update log

3 updates

About Merck & Co.

The team behind Sacituzumab tirumotecan (sac-TMT)

Merck & Co.

Keytruda, sac-TMT antibody-drug conjugate, oncology

US drugmaker (MSD outside North America) behind Keytruda. Its main bet on the next generation of cancer drugs is sac-TMT, a TROP2 antibody-drug conjugate licensed from China's Kelun-Biotech.

Sac-TMT: 17 global phase 3 trials enrolling 15,000+ patients, 10 of them in women's cancers.
First global phase 3 win (TroFuse-005, endometrial cancer) in May 2026, on both survival and progression.
Licensed outside Greater China from Kelun-Biotech in May 2022.

merck.com (opens merck.com)Company profile →

Headquarters: United States
Status: Public
Valuation: public
Works in: BiotechAntibody drugs
Coverage: 1 program · 3 updateslatest 29 May 2026checked 11 Oct
Partners: Kelun-Biotech (opens filingreader.com)

Spec

Sacituzumab tirumotecan (sac-TMT)

Global phase 3 trials

17^R (reported)

Patients in phase 3 program

15,000+^R (reported)

TroFuse-005 patients

776^R (reported)

Dose (TroFuse-005)

4 mg/kg every 2 weeks^R (reported)

China lung trial with Keytruda: PFS

65% lower risk vs Keytruda alone^R (reported)

Sacituzumab tirumotecan (sac-TMT)

Milestones

Most important updates

Upcoming

Current obstacles

Physics limits

How it works

TROP2 on the tumour surface

Belotecan-derived poison

Built to hold in blood

Partnered with Keytruda

Spec sheet

Update log

Fri 29 May

Mon 18 May

Mon 10 Mar 2025

About Merck & Co.

Current obstacles

Physics limits

How it works

TROP2 on the tumour surface

Belotecan-derived poison

Built to hold in blood

Partnered with Keytruda

Spec sheet

Update log

Fri 29 May

Mon 18 May

Mon 10 Mar 2025

About Merck & Co.