Kelun's TROP2-Targeted ADC Shows Promise in First-Line Lung Cancer Trial
Key Insights
Kelun-Biotech (search)'s sacituzumab tirumotecan combined with Keytruda met its primary endpoint of progression-free survival in the Phase III OptiTROP-Lung05 trial for first-line NSCLC patients with PD-L1 (search) expression ≥1%.
The combination demonstrated statistically significant improvements in progression-free survival compared to Keytruda alone and showed a positive trend toward improved overall survival.
While the results are encouraging for the Chinese market, global adoption may be limited as the study did not compare against the current standard of care of Keytruda plus chemotherapy.
Kelun-Biotech (search) has announced positive results from its Phase III OptiTROP-Lung05 trial, demonstrating that sacituzumab tirumotecan (sac-TMT) combined with Keytruda (pembrolizumab) significantly improved progression-free survival compared to Keytruda monotherapy in first-line non-small cell lung cancer (NSCLC) patients with PD-L1 (search) expression ≥1%.
The Chinese phase 3 trial met its primary endpoint of progression-free survival with the combination therapy versus Keytruda alone. The company also reported a positive trend in overall survival, though detailed results remain limited. Sac-TMT is a TROP2 (search)-targeting antibody-drug conjugate (ADC) that acts by targeting the trophoblast cell surface antigen-2 protein, which is widely expressed across various solid tumors and often associated with poor patient prognosis.
Trial Design and Patient Population
The OptiTROP-Lung05 trial was conducted entirely in China and enrolled first-line NSCLC patients with programmed death ligand 1 (PD-L1 (search))-positive disease. The study compared the combination of sac-TMT plus Keytruda against Keytruda monotherapy, demonstrating statistically significant improvements in progression-free survival for the combination arm.
Regulatory and Commercial Implications
Following this positive topline readout, Kelun plans to discuss the results with China's National Medical Products Administration (NMPA) to seek approval for sac-TMT in the frontline NSCLC setting. If approved, the Keytruda-sac-TMT combination could potentially become the local standard of care in China.
Biswajit Podder, oncology and hematology analyst at GlobalData, noted that "if the magnitude of PFS and eventually OS benefit is clearly better than Keytruda monotherapy with a manageable safety profile, I would expect it to become a new SOC for PD-L1 (search) positive patients who are suitable for an ADC and either wish to avoid or delay platinum chemotherapy."
Global Development Strategy
MSD holds commercialization rights to sac-TMT outside of greater China and has a comprehensive global development program underway. The drug previously received breakthrough therapy designation from the US Food and Drug Administration for pretreated, advanced or metastatic NSCLC with epidermal growth factor receptor mutations.
Earlier this month, MSD signed a funding agreement with Blackstone Life Sciences (search), securing $700 million for sac-TMT development in exchange for "low-to-mid single-digit royalties" on net sales across MSD's marketing territories.
Competitive Landscape and Future Trials
The current standard of care in first-line NSCLC is Keytruda plus platinum chemotherapy, which the OptiTROP-Lung05 trial did not directly compare against. Kelun is addressing this limitation through the OptiTROP-Lung06 trial, which tests sac-TMT plus Keytruda versus Keytruda plus chemotherapy and is expected to read out next year.
Other companies are pursuing similar strategies in the TROP2 (search) ADC space. Gilead is exploring the same indication in the Evoke-03 trial of its TROP2 ADC Trodelvy, while AstraZeneca is testing its rival Datroway in different PD-L1 (search) expression populations through the Tropion-Lung07 and Tropion-Lung08 trials.
Market Outlook and Limitations
Despite the encouraging results, Podder cautioned that the study has not yet proved that sac-TMT plus Keytruda is superior or even non-inferior to the standard chemo-immunotherapy combination. He expects initial uptake in China to be strongest in "tertiary centres that already have experience with ADCs and sac-TMT in later lines."
For global adoption, Podder stated that "for sac-TMT plus Keytruda to become a true worldwide standard, we will need to see data from the MSD-led global Phase III programmes that test this combination in populations more representative of wide practice and ideally against chemo immunotherapy comparators."
Analysts at GlobalData forecast that sac-TMT will generate $3.37 billion in revenue by 2031, reflecting the significant commercial potential of this TROP2 (search)-targeted therapy in the evolving lung cancer treatment landscape.