TROP2 ADC competition and treatment design in first-line NSCLC Report Interpretation

Overview

This report examines the competition between Daiichi Sankyo/AstraZeneca's Datroway and Kelun/Merck's sac-TMT in first-line non-small-cell lung cancer. Bernstein argues that the decisive issue is not simply which ADC is superior, but whether adding platinum chemotherapy to an ADC-immunotherapy regimen creates enough incremental benefit to justify a triplet over a chemotherapy-free doublet.

Core views

Bernstein frames the approaching readouts from Datroway's Phase 3 Avanzar study and sac-TMT's China-only Phase 3 OptiTROP-Lung06 study as a test of treatment design in first-line NSCLC. Avanzar evaluates Datroway with Imfinzi and carboplatin against Keytruda plus platinum and pemetrexed in first-line non-squamous, TROP2-QCS-positive NSCLC without actionable genomic alterations. Bernstein expects a positive Avanzar result despite market skepticism. OptiTROP-Lung06 evaluates sac-TMT plus Keytruda against Keytruda plus chemotherapy in first-line PD-L1 TPS below 1% NSCLC; Kelun has already reported statistically significant PFS improvement and a positive OS trend, with fuller data expected at ESMO in October. The institution outlines two potential outcomes. In a “triplet better” case, Avanzar produces a PFS hazard ratio materially lower than the expected OptiTROP-Lung06 result, which Bernstein assumes should be below 0.7. That would support the clinical value of adding platinum and raise the likelihood that Datroway triplets become the preferred TROP2 ADC regimen for non-squamous, TROP2-QCS-positive patients. In this outcome, sac-TMT's first-line development could remain focused on its existing TroFuse-007 and TroFuse-023 programs, representing a USD12bn TAM. In a “doublet enough” case, both trials deliver similar PFS hazard ratios below 0.7, implying little additional benefit from platinum. Bernstein views that as positive for both drugs because a TROP2 ADC plus immunotherapy regimen could remove chemotherapy while improving efficacy and safety. It would make Datroway's TROPION-Lung07 doublet data in the first half of 2027 the next key readout and could support sac-TMT expansion into PD-L1 TPS below 50% disease, with a maximum USD27bn TAM. Existing evidence is encouraging but not definitive. In Phase 1b TROPION-Lung02, Datroway plus Keytruda and carboplatin in 42 first-line non-squamous patients showed a 57% confirmed response rate, 18.0-month median duration of response and 10.8-month median PFS, versus 48%, 11.2 months and 8.8 months, respectively, in the separate 410-patient KEYNOTE-189 standard-of-care dataset. Bernstein stresses that this is a cross-trial comparison rather than an in-study comparison and requires Phase 3 confirmation. Datroway's results also appear stronger in non-squamous than squamous disease and in TROP2-QCS-positive than negative patients. In TROPION-Lung01, the biomarker-positive group had median PFS of 6.9 months versus 4.1 months for docetaxel, HR 0.57, whereas the biomarker-negative group had 2.9 months versus 4.0 months, HR 1.16. Bernstein notes that TROP2-QCS-positive patients account for about two-thirds of non-squamous NSCLC and about 50% of overall NSCLC. Sac-TMT has shown activity across histologies and does not appear to require biomarker selection. In OptiTROP-Lung05, sac-TMT plus Keytruda produced PFS HR 0.35 against Keytruda alone in first-line PD-L1 TPS at least 1% NSCLC; the 12-month PFS rate was 60% versus 22% in the PD-L1 TPS 1% to 49% subgroup, with HR 0.28. However, Bernstein cautions that Keytruda monotherapy was not the appropriate global comparator for this subgroup because Keytruda plus chemotherapy is the standard of care. The PD-L1 TPS 1% to 49% population represented 60% of the sample, and KEYNOTE-189 reported a 43% 12-month PFS rate for Keytruda plus platinum and pemetrexed in non-squamous disease. The report therefore believes the trial's comparator likely enhanced sac-TMT's apparent efficacy profile and makes OptiTROP-Lung06 important for clarifying its real first-line potential. The report links the drugs' clinical profiles to their molecular designs. Datroway has a protease-cleavable linker that requires cellular internalization before payload release, which Bernstein believes explains its dependence on sufficient TROP2 expression and the TROP2-QCS patient-selection strategy. Sac-TMT's acid/pH-sensitive hydrolyzable linker may release payload both after internalization and in the acidic tumor microenvironment. Bernstein argues this may explain histology-agnostic activity and less need for biomarker selection, but also its chemotherapy-like hematologic toxicity. In OptiTROP-Lung05, sac-TMT plus Keytruda had anemia in 88% of patients, leukopenia in 46% and neutropenia in 45%, while Datroway showed much less of these toxicities in the cited comparison. Those safety differences shape development strategy. Bernstein believes overlapping hematologic toxicity has made Kelun and Merck cautious about combining sac-TMT with chemotherapy; the report notes no ongoing global Phase 3 sac-TMT study combines the drug with chemotherapy. This leaves a major first-line population insufficiently addressed while the platinum question remains open: PD-L1 TPS below 50% represents about 80% of first-line NSCLC. Datroway's program, in contrast, retains carboplatin in Avanzar and includes both doublet and triplet approaches in TROPION-Lung07 because Daiichi Sankyo and AstraZeneca believe chemotherapy can induce an initial deep response that may benefit PFS and OS. Bernstein expects detailed OptiTROP-Lung06 data and Merck's October ESMO oncology session to clarify whether Merck pursues a more aggressive global sac-TMT strategy.

Analysis framework

Bernstein compares upcoming Phase 3 trial designs and PFS scenarios, then assesses earlier efficacy and safety data, patient-selection differences, development-program scope and the molecular linker mechanisms that may drive each drug's clinical profile. It uses cross-trial comparisons cautiously and highlights comparator limitations where relevant.

Methodology notes

• Other

  Cross-trial efficacy and safety comparison

  The report compares response, PFS, duration of response and adverse-event data across separate studies to contextualize the two ADCs, while explicitly noting that these comparisons do not replace head-to-head or confirmatory Phase 3 evidence.

• Industry AnalysisVolume-price decomposition

  Patient-population-based TAM comparison

  Bernstein estimates commercial opportunity by linking each development strategy to its addressable first-line NSCLC population, producing USD13bn and USD27bn TAM estimates for Datroway and sac-TMT, respectively.

Asset mapping & comparison

Structured mapping from thesis to named assets (strengths, weaknesses, peers, risks).

• Daiichi Sankyo (4568.JP)

  Datroway co-developer; Avanzar is central to the report's triplet-versus-doublet thesis.

  Strengths

  Bernstein expects a positive Avanzar outcome and highlights Datroway's limited hematologic toxicity and strong biomarker-selected efficacy.

  Weaknesses

  Datroway appears dependent on non-squamous, TROP2-QCS-positive patient selection, narrowing its addressable population.

  Comparison

  A robust Avanzar PFS HR materially below sac-TMT's result would favor Datroway triplets.

  Risks

  Negative Avanzar or TROPION-Lung15 topline results are stated downside risks.

• AstraZeneca (AZN.LN)

  Datroway co-developer with Daiichi Sankyo.

  Strengths

  Datroway's triplet program retains platinum to pursue deep initial responses and potentially improve PFS and OS.

  Weaknesses

  The addressable population is limited by TROP2-QCS selection and non-squamous focus.

  Comparison

  The report contrasts Datroway's more aggressive first-line program with Merck's more conservative sac-TMT plans.

  Risks

  The report cites downside if Datroway is removed from AstraZeneca's model or if Enhertu no longer grows.

• Sichuan Kelun-Biotech Biopharmaceutical (06990.HK)

  sac-TMT co-developer; explicit covered company.

  Strengths

  sac-TMT has shown strong efficacy signals across squamous and non-squamous histology and may not need biomarker selection.

  Weaknesses

  Chemo-like hematologic toxicity may constrain chemotherapy combinations and current Phase 3 scope.

  Comparison

  sac-TMT has broader theoretical first-line TAM than biomarker-selected Datroway, but its current program is limited to about USD12bn TAM.

  Risks

  Trial results could be worse than expected, domestic sales ramp-up could disappoint, and global licensing income may not materialize.

• Merck (MRK)

  sac-TMT partner and explicit covered company.

  Strengths

  Bernstein sees sac-TMT as highly competitive and notes Merck's expertise in trial design and execution.

  Weaknesses

  Merck's first-line mNSCLC program is described as more conservative and commercially riskier than Datroway's, with limited penetration possible because of tolerability trade-offs.

  Comparison

  Merck is likely behind AstraZeneca and Daiichi Sankyo in aggressive first-line development unless it announces expanded plans.

  Risks

  The report identifies risks from Gardasil underperformance in China, HIV competition, slower PrEP development, and weaker pipeline or M&A outcomes.

• Gilead Sciences (GILD)

  Comparable TROP2 ADC developer through Trodelvy.

  Strengths

  Trodelvy was first to approval in 2L+ TNBC in 2020 and generated USD1.4bn sales in 2025.

  Weaknesses

  Bernstein says late-stage potential is constrained by lung-cancer efficacy failures, including EVOKE-01 and EVOKE-03.

  Comparison

  The report focuses primarily on sac-TMT after describing Trodelvy as limited by lung-cancer failures.

Key data

• OptiTROP-Lung05 PFS HR0.35sac-TMT plus Keytruda versus Keytruda alone in first-line PD-L1 TPS ≥1% NSCLC
• OptiTROP-Lung05 12-month PFS rate60% vs 22%sac-TMT plus Keytruda versus Keytruda alone in the PD-L1 TPS 1%–49% subgroup
• KEYNOTE-189 12-month PFS rate43%Keytruda plus platinum plus pemetrexed in first-line non-squamous NSCLC
• TROPION-Lung02 confirmed response rate57% vs 48%Datroway plus Keytruda plus carboplatin versus the separate KEYNOTE-189 dataset
• TROPION-Lung02 median duration of response18.0 months vs 11.2 monthsDatroway regimen versus separate KEYNOTE-189 dataset
• TROPION-Lung02 median PFS10.8 months vs 8.8 monthsDatroway regimen versus separate KEYNOTE-189 dataset
• TROPION-Lung01 TROP2-QCS-positive PFS HR0.57Datroway versus docetaxel in the biomarker-positive population
• Datroway 1L NSCLC TAMUSD13bnnon-squamous, TROP2-QCS-positive population
• sac-TMT 1L NSCLC maximum TAMUSD27bnoverall NSCLC regardless of histology

Impact & implications

Bernstein believes the imminent data could determine whether platinum remains necessary in TROP2 ADC plus immunotherapy treatment. A clearly superior Datroway triplet result would strengthen Datroway's position in its biomarker-selected population, while comparable strong doublet results would support broader chemotherapy-free development for both agents, especially sac-TMT.

Risks

• Negative topline results from Datroway's Avanzar study in first-line TROP2-positive non-squamous NSCLC.
• Negative topline results from Datroway's TROPION-Lung15 study in second-line EGFR-mutant NSCLC.
• sac-TMT's hematologic toxicities may limit compatibility with chemotherapy and restrict first-line development.
• sac-TMT's prior efficacy data may overstate global potential because Keytruda monotherapy was a weak comparator for much of OptiTROP-Lung05.
• Daiichi Sankyo faces stated downside from a lack of sales-growth acceleration for Enhertu in early HER2-positive breast cancer.

What to watch

• Full OptiTROP-Lung06 data presentation at ESMO in October, including the PFS magnitude and OS trend.
• Avanzar Phase 3 readout in first-line non-squamous, TROP2-QCS-positive NSCLC.
• Whether Avanzar's PFS HR is materially lower than sac-TMT's expected PFS HR below 0.7.
• Merck's October ESMO oncology session and any announcement of more aggressive global sac-TMT development.
• Datroway TROPION-Lung15 readout and subsequent TROPION-Lung07 doublet data expected in the first half of 2027.