Novel computational pathology-based TROP2 biomarker for datopotamab deruxtecan was predictive of clinical outcomes in patients with non-small cell lung cancer in TROPION-Lung01 Phase III trial

In patients with TROP2-QCS biomarker positive tumours, datopotamab deruxtecan demonstrated a meaningfully greater magnitude of efficacy versus docetaxel than in the overall trial population. These results will be featured in a Presidential Symposium (PL02.11) at the IASLC 2024 World Conference on Lung Cancer (WCLC) hosted by the International Association for the Study of Lung Cancer.

TROP2 is a protein broadly expressed in NSCLC on the surface of and inside tumour cells. When assessed using conventional immunohistochemistry (IHC)-based pathology, TROP2 expression has not been predictive of patient responses to TROP2-directed antibody drug conjugates (ADC).  QCS is a fully supervised computational pathology platform, developed by AstraZeneca, that analyses digitised images of patient tissue samples and precisely quantifies targets, like TROP2, on and inside a tumour cell. Datopotamab deruxtecan is a specifically engineered TROP2-directed DXd ADC discovered by Daiichi Sankyo and being jointly developed by AstraZeneca and Daiichi Sankyo.

In this analysis, QCS was used to analyse tissue samples collected from patients in TROPION-Lung01. This produced a normalised membrane ratio for each tumour cell in each sample. Patients’ tumours were considered TROP2-QCS biomarker positive if the majority ( greater than 75%) of tumour cells exhibited a ratio below a predetermined value  less than 0.56), indicating a greater proportion of TROP2 in the cytoplasm. The analysis showed a greater proportion of patients with nonsquamous NSCLC were considered TROP2-QCS biomarker positive than those with squamous NSCLC (66% versus 44%, respectively). The threshold for biomarker positivity was optimised for progression-free survival (PFS) in the subgroup of patients with nonsquamous NSCLC without actionable genomic alterations because it represents a population with significant unmet medical need and without actionable biomarkers.

In patients with TROP2-QCS biomarker positive tumours (60% of the biomarker evaluable population including patients with nonsquamous and squamous NSCLC), datopotamab deruxtecan reduced the risk of disease progression or death by 43% versus docetaxel (median PFS of 6.9 versus 4.1 months; hazard ratio [HR] 0.57; 95% confidence interval [CI] 0.41-0.79).. By comparison, in the primary analysis of the overall trial population, datopotamab deruxtecan reduced the risk of disease progression or death by 25% versus docetaxel (PFS of 4.4 versus 3.7 months; HR 0.75; 95% CI 0.62-0.91; p=0.004) as presented at the 2023 European Society for Medical Oncology Congress.⁵

In the subgroup of patients with nonsquamous NSCLC without actionable genomic alterations and with TROP2-QCS biomarker positive tumours, datopotamab deruxtecan reduced the risk of disease progression or death by 48% (PFS of 7.2 versus 4.1 months; HR 0.52; 95% CI 0.35-0.78).

Marina Garassino, MD, The University of Chicago, Professor of Medicine and investigator in the trial, said: “TROP2 is broadly expressed on solid tumour cells, including non-small cell lung cancer, but it has yet to be established as a predictive biomarker for any TROP2-directed antibody drug conjugate. We have shown with this analysis that the more precise quantitative measurement of TROP2 on and inside tumour cells, enabled by AstraZeneca’s computational pathology platform, can identify which patients with non-small cell lung cancer are most likely to benefit from treatment with datopotamab deruxtecan.”

Susan Galbraith, Executive Vice President, Oncology R&D, AstraZeneca, said: “This analysis demonstrates the power of our computational pathology platform to discover new predictive biomarkers and substantially improve patient selection for datopotamab deruxtecan. It also has great potential to help more precisely select patients across our broader antibody drug conjugate portfolio. ?We are excited to extend our collaboration with Roche Tissue Diagnostics with the aim of validating this exploratory approach for TROP2, developing the companion diagnostic and bringing it to the clinic as quickly as possible.”

Ken Takeshita, MD, Global Head, R&D, Daiichi Sankyo, said: “The results from the QCS analysis support the potential of TROP2, as measured by quantitative continuous scoring, as a predictive biomarker for datopotamab deruxtecan and begin to answer the question of why certain patients with non-small cell lung cancer respond better to treatment. These insights are critical to advancing our understanding of how we can more precisely identify patients with non-small cell lung cancer who may benefit from treatment with our TROP2-directed antibody drug conjugate.”

In the biomarker evaluable population, no new safety concerns were identified and rates of Grade 3 or higher treatment-related adverse events (TRAE) were similar regardless of TROP2 status. In patients with TROP2-QCS biomarker positive tumours, Grade 3 or higher TRAEs occurred in 30% and 46% of patients in the datopotamab deruxtecan and docetaxel arms, respectively. The most common Grade 3 or higher TRAEs were stomatitis (7%, 3%) and ocular surface events (3%, 0%). Grade 3 or higher adjudicated drug-related interstitial lung disease events occurred in 3% and 1% of patients in the datopotamab deruxtecan and docetaxel arms, respectively.