Kelun-Biotech lung cancer data update: first-line treatment delays progression, later-line survival benefit persists

Why is first-line treatment the biggest increment from this data update?

OptiTROP-Lung06 extends the evidence for sac-TMT into first-line treatment of PD-L1-negative advanced non-squamous non-small cell lung cancer. At a median follow-up of 9.7 months, median progression-free survival was 15 months with sac-TMT plus pembrolizumab, versus 5.7 months with pembrolizumab plus chemotherapy in the same trial; the risk of disease progression or death was reduced by 51%, a statistically significant difference.
The difficulty of treating this population gives the result added weight: in the PD-L1-negative subgroup of the historical KEYNOTE-189 study, adding pembrolizumab to chemotherapy increased median progression-free survival by only about 1 month. Lung06, in a direct randomized comparison, showed that replacing chemotherapy with sac-TMT substantially prolonged the duration of disease control.
Overall survival data remain immature, with a hazard ratio for death of 0.58 showing a favorable trend. Thus, what is established in first-line treatment is a delay in disease progression; the magnitude of any overall survival benefit depends on further follow-up.

In Lung06, the incidence of grade three or higher treatment-emergent adverse events was 47.6% in the sac-TMT plus pembrolizumab group, lower than the 60.6% in the chemotherapy plus pembrolizumab group. Bernstein therefore believes the combination offers a more favorable overall safety profile while prolonging progression-free survival.
Most cases of stomatitis associated with sac-TMT, an adverse event that has attracted attention, were grade one or two, with a grade three incidence of 2.2%; grade three interstitial lung disease occurred in 1.7% of patients, compared with 3.1% in the control group. These data support its potential for first-line use, but the combination still carries a clear adverse-event burden.

In the final analysis of OptiTROP-Lung04, which studied non-squamous non-small cell lung cancer that had progressed after EGFR-targeted therapy, median overall survival at a median follow-up of 32.3 months was 25.9 months in the sac-TMT group and 17.4 months in the platinum-based chemotherapy group, a difference of 8.5 months. The hazard ratio for death was 0.69, meeting the prespecified threshold for statistical significance.
Compared with the interim analysis at a median follow-up of 18.9 months, the hazard ratio for death rose from 0.60 to 0.69, meaning the relative reduction in the risk of death narrowed from 40% to 31%. Longer follow-up confirmed the survival advantage, but the magnitude of benefit was smaller than in the interim readout.
After adjustment for the effect of subsequent ADC treatment using a prespecified model, the hazard ratio for death changed from 0.56 at the interim analysis to 0.57 at the final analysis, remaining broadly stable. This adjusted analysis supports the primary result; the final hazard ratio in the original randomized population remains 0.69.

Combining Lung06 with positive results from the earlier Lung05 first-line study in PD-L1-positive lung cancer, Bernstein believes sac-TMT has potential across a broader population of patients with differing PD-L1 expression. The commercial rationale is expansion from later-line to first-line treatment, rather than merely strengthening its existing later-line position.
Lung06 is a phase III study conducted in China. Bernstein believes the results improve the outlook for the global trials of Kelun-Biotech and Merck’s TROP2 ADC, and is watching whether Merck announces additional phase III programs beyond its two existing global phase III first-line lung cancer studies in patients with high PD-L1 expression and in squamous cancer.
The firm rates Kelun-Biotech Outperform with a target price of HK$526, approximately 14% above the closing price of HK$460.40 on 23 October 2026. Its valuation combines discounted cash flow and peak sales methods; realization depends on further trials, the ramp-up of domestic sales and global licensing revenue.