# The Results of Phase III OptiTROP-Lung05 Study of Sacituzumab Tirumotecan (sac-TMT) Presented as an ASCO Oral Presentation and Simultaneously Published in The Lancet

- Link: https://www.thailand-business-news.com/pr-news/the-results-of-phase-iii-optitrop-lung05-study-of-sacituzumab-tirumotecan-sac-tmt-presented-as-an-asco-oral-presentation-and-simultaneously-published-in-the-lancet
- Published: 2026-05-30T21:01:00+07:00
- Author: PR Newswire

|   |

CHENGDU, China, May 30, 2026 /PRNewswire/ — Sichuan Kelun-Biotech Biopharmaceutical
Co., Ltd. (the "Company", 6990.HK) announced today that at the 2026 American Society
of Clinical Oncology (ASCO) Annual Meeting in Chicago, the results of the Phase 
III clinical study OptiTROP-Lung05, evaluating the company’s TROP2 ADC sacituzumab
tirumotecan (sac-TMT, also known as SKB264/MK-2870)(佳泰莱^(®)) in combination with
pembrolizumab (KEYTRUDA^(®)^([1]), MSD’s anti-programmed cell death protein 1 (PD-
1) antibody) as first-line treatment for Programmed Death-Ligand 1 (PD-L1) Tumor
Proportion Score (TPS)≥1% non-small cell lung cancer (NSCLC), was presented as an
oral presentation by Professor Caicun Zhou from Shanghai East Hospital, Tongji University(
Abstract #8506, Lung Cancer – Metastatic Non-Small Cell).

[[

Sac-TMT is designed with a unique, bifunctional linker and differentiated belotecan-
derivative payload. The linker is conjugated via cysteine, which maximizes payload
delivery to tumor cells both through its irreversible connection with the high-affinity
and targeting anti-TROP2 monoclonal antibody sacituzumab and its pH-sensitive cleavage
from a moderately toxic novel topoisomerase I inhibitor payload in the lysosome,
with a drug-to-antibody-ratio (DAR) of 7.4.

[[

In the OptiTROP-Lung05 study, a total of 413 patients were randomized (1:1) to receive
either sac-TMT in combination with pembrolizumab or pembrolizumab monotherapy.

[[

As of the data cutoff date (September 29, 2025), with a median follow‑up of 10.5
months, the study demonstrated that:

 ◦ Progression-free survival (PFS) showed statistically significant and clinically
   meaningful benefit in sac-TMT plus pembrolizumab compared with pembrolizumab 
   alone. The median PFS assessed by blinded independent central review (BICR) was
   not reached (NR) vs 5.7 months (HR=0.35; 95% CI: 0.26-0.47; p<0.0001). The 12-
   month PFS rate was 62.4% vs 29.0%.

[[

 ◦ Consistent benefit across prespecified subgroups: In patients with PD‑L1 TPS 
   ≥50% and TPS 1–49%, the PFS HRs were 0.47 (95% CI: 0.29–0.77) and 0.28 (95% CI:
   0.19–0.41), respectively. In patients with non‑squamous and squamous NSCLC, the
   PFS HRs were 0.28 (95% CI: 0.18–0.43) and 0.44 (95% CI: 0.29–0.66), respectively.

[[

[[

 ◦ Overall survival (OS) was not yet mature but showed a positive trend: median 
   OS was NR vs 14.5 months (HR = 0.55; 95% CI: 0.36–0.85). The 12‑month OS rate
   was 80.4% vs 68.9%.

 ◦ The combination group showed improvements over pembrolizumab monotherapy group
   in objective response rate (ORR) (70.2% vs 42.0%), deep response rate (49.0% 
   vs 25.9%), and 12-month duration of response rate (77.7% vs 59.4%).

[[

The incidence of grade ≥3 treatment-emergent adverse events (TEAEs) was higher in
the combination group, primarily driven by the expected hematologic adverse events
of sac-TMT. Incidence of discontinuation of pembrolizumab due to TEAEs was similar
in both groups. No sac-TMT-related deaths occurred. Adverse events of special interest(
AEOSIs) were consistent with the known safety profiles of each individual agent,
and no new safety signals were identified.

The interim analysis results show that sac-TMT plus pembrolizumab significantly 
prolonged PFS and reduced the risk of disease progression or death compared with
pembrolizumab alone, with consistent PFS benefits observed across all prespecified
subgroups (including PD‑L1 expression levels and histological subtypes). A positive
trend in OS was also observed. Furthermore, the overall safety profile of sac-TMT
in combination with pembrolizumab was manageable, consistent with the established
safety profiles of sac-TMT alone or pembrolizumab alone.

Notably, the findings of OptiTROP-Lung05 have been simultaneously published in _The_
_Lancet_（Impact Factor=88.5）, indicating that its clinical and academic value 
has received dual recognition from a leading international academic conference and
an authoritative journal.

[[

Professor Caicun Zhou, the national leading principal investigator from Shanghai
East Hospital, Tongji University, said: "The positive results of the OptiTROP‑Lung05
study are encouraging. The study not only supports the application of sac‑TMT in
an earlier-line setting for lung cancer, but also provides evidence of the ‘ADC+
IO’ synergistic strategy being evaluated in the first-line setting for PD‑L1‑positive
advanced NSCLC, potentially bringing a new option to a broad population of patients
with lung cancer."

  |

[1] KEYTRUDA^(®) (pembrolizumab) is a registered trademark of Merck Sharp & Dohme LLC (MSD), a subsidiary of Merck & Co., Inc., Rahway, NJ, USA.

  |  
 |   |

**About sac-TMT(****佳泰莱****^(®)****)**

Sac-TMT, a core product of the Company, is a novel human TROP2 ADC in which the 
Company has proprietary intellectual property rights, targeting advanced solid tumors
such as NSCLC, breast cancer (BC), gastric cancer (GC), gynecological tumors and
genitourinary tumors, among others. Sac-TMT is developed with a unique, bifunctional
linker that maximizes payload delivery to tumor cells both through its irreversible
connection with the anti-TROP2 monoclonal antibody sacituzumab and its pH-sensitive
cleavage from a belotecan-derivative topoisomerase I inhibitor payload in the lysosome,
with a drug-to-antibody-ratio (DAR) of 7.4. Sac-TMT specifically recognizes TROP2
on the surface of tumor cells by recombinant anti-TROP2 humanized monoclonal antibodies,
which is then endocytosed by tumor cells and releases the payload KL610023 intracellularly.
KL610023, as a topoisomerase I inhibitor, induces DNA damage to tumor cells, which
in turn leads to cell-cycle arrest and apoptosis. In addition, it also releases 
KL610023 in the tumor microenvironment. Given that KL610023 is membrane permeable,
it can enable a bystander effect, or in other words kill adjacent tumor cells.

In May 2022, the Company licensed the exclusive rights to MSD (the tradename of 
Merck & Co., Inc, Rahway, NJ, USA) to develop, use, manufacture and commercialize
sac-TMT in all territories outside of Greater China (which includes Mainland China,
Hong Kong, Macao and Taiwan).

To date, four indications for sac-TMT have been approved and marketed in China for:
1) unresectable locally advanced or metastatic triple‑negative breast cancer (TNBC)
who have received at least two prior systemic therapies (at least one of them for
advanced or metastatic setting); 2) EGFR mutant-positive locally advanced or metastatic
non-squamous NSCLC following progression on epidermal growth factor receptor tyrosine
kinase inhibitor (EGFR-TKI) therapy and platinum-based chemotherapy; 3) epidermal
growth factor receptor (EGFR) mutant-positive locally advanced or metastatic non-
squamous NSCLC who progressed after treatment with EGFR-TKI therapy; 4) unresectable
or metastatic hormone receptor-positive (HR+)/human epidermal growth factor receptor
2-negative (HER2-) (Immunohistochemistry (IHC) 0, IHC 1+ or IHC 2+/In Situ Hybridization(
ISH)-) BC who have received prior endocrine therapy and at least one line of chemotherapy
in advanced setting. The first two indications above have been included in China’s
National Reimbursement Drug List (NRDL). This inclusion is expected to bring clinically
meaningful benefits to a greater number of patients with BC and NSCLC. Additionally,
sac-TMT has been granted six Breakthrough Therapy Designations (BTDs) by the National
Medical Products Administration (NMPA).

Sac-TMT is the world’s first TROP2 ADC drug approved for marketing in lung cancer.
A new indication application for sac-TMT in combination with pembrolizumab (KEYTRUDA
^(®)) as first‑line treatment for locally advanced or metastatic NSCLC who have 
PD-L1 TPS≥1% and are EGFR-negative and anaplastic lymphoma kinase (ALK)-negative
has been accepted for review by the NMPA, and has entered the priority review and
approval process. As of today, Kelun-Biotech has initiated 9 registrational clinical
studies in China. MSD is evaluating 17 ongoing global Phase III clinical studies
of sac-TMT as a monotherapy or in combination with pembrolizumab or other anti-cancer
agents for several types of cancer. These studies are sponsored and led by MSD.

**About Kelun-Biotech**

Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical, which focuses
on the R&D, manufacturing, commercialization and global collaboration of innovative
biological drugs and small molecule drugs. Kelun-Biotech focuses on major disease
areas such as solid tumors, autoimmune, and metabolic diseases, and in establishing
a globalized drug development and industrialization platform to address the unmet
medical needs in China and the rest of world. Kelun-Biotech is committed to becoming
a leading global enterprise in the field of innovative drugs. At present, Kelun-
Biotech has more than 30 ongoing key innovative drug projects, of which 4 projects
with 8 indications have been approved for marketing, 1 project is in the NDA stage
and more than 10 projects are in the clinical stage. Kelun-Biotech has established
one of the world’s leading proprietary ADC and novel DC platforms, OptiDC™, and 
has 2 ADC projects with 5 indications approved for marketing, and multiple ADC and
novel DC assets in clinical or preclinical research stage. For more information,
please visit [https://en.kelun-biotech.com/](https://en.kelun-biotech.com/).

---

  |  This article was produced by Cision PR Newswire, our trusted news partner. The views expressed and the content presented here are solely those of the author and may not fully reflect the opinions of Thailand Business News. |

---

 
**Read the original article :** [The Results of Phase III OptiTROP-Lung05 Study of Sacituzumab Tirumotecan (sac-TMT) Presented as an ASCO Oral Presentation and Simultaneously Published in The Lancet ](http://www.prnasia.com/story/archive/4971874_AE71874_0?rand=184833)