Merck & Co., Inc.: Initial take on Sac-TMT OptiTROP-Lung05 abstract

Research evidence excerpt

Merck & Co., Inc.: Initial take on Sac-TMT OptiTROP-Lung05 abstract

Update

May 22, 2026 01:22 AM GMT

Morgan Stanley & Co. LLCMMerck & Co., Inc. | North America Terence C Flynn, Ph.D.

Equity Analyst

Initial take on Sac-TMT Terence.Flynn@morganstanley.comHailey Horowitz +1 212 761-2230

Research Associate

Hailey.Horowitz@morganstanley.com +1 212 761-5264

OptiTROP-Lung05 abstract Alexander Yevdokimov, Ph.D.

Alexander.Yevdokimov@morganstanley.com +1 212 761-2167

The ASCO abstract for MRK/Kelun's Ph3 China-only OpiTROP-Lung05 trial of

Chris Yu, J.D., Ph.D.

sacituzumab tirumotecan (sac-TMT; ADC to TROP2) in 1L PD-L1-positive NSCLC Equity Analyst

was released on 5/21 - median PFS was not reached for sac-TMT vs. 5.7mos for Chris.L.Yu@morganstanley.com +1 212 761-2535

Connor M Massari

Keytruda (p< 0.0001, see below). The HR of 0.35 implies a mPFS for Sac-TMT Equity Analyst

+Keytruda of at least 16 mos, which we believe is generally in line with investor Connor.Massari@morganstanley.com +1 212 761-2417

Damien H Kerner

expectations of ~15-20mos; see our preview HERE. The PFS performance of the Research Associate

Keytruda control arm also appears in line with expectations (see Exhibit 1 below). Damien.H.Kerner@morganstanley.com +1 212 761-3829

With respect to sac-TMT safety/tolerability cytopenias and stomatitis were noted, Morgan Stanley India Company Private Limited+

but no mention of ILD in the abstract. Bottom line we view this as an incremental Saket Agarwal

positive update for sac-TMT, but we await full details at ASCO on subgroups (see Saket.Agarwal@morganstanley.com +91 22 6995-4012

below) and safety, and we also see data from the OpiTROP-Lung06 Ph3 China trial

(vs. Keytruda+chemo in NSQ PD-L1- population) later this year as another input into Merck & Co., Inc.