ASCO 2026: A quiet conference for European pharma, but AstraZeneca and Roche both have work to do Proactive uses images sourced from Shutterstock
This year’s American Society of Clinical Oncology (ASCO) conference has been a subdued affair for European pharmaceutical companies, with no major plenary presentations and little data capable of moving share prices materially.
But beneath the quiet surface, both AstraZeneca PLC (LSE:AZN, NASDAQ:AZN) and Roche emerged with important questions to answer about the commercial futures of key pipeline assets.
For AZ, the most significant development came from a rival’s data rather than its own. Phase II results from the OptiTROP-Lung05 study of sac-TMT, a lung cancer drug being developed by Merck and Chinese pharmaceutical company Kelun, demonstrated strong efficacy in first-line non-small cell lung cancer (NSCLC), the same indication where AstraZeneca is developing its own TROP2 antibody-drug conjugate (ADC) Datroway.
ADCs are a class of cancer treatments that combine a targeted antibody with a cell-killing payload, designed to deliver chemotherapy directly to tumour cells while sparing healthy tissue.
The sac-TMT data showed a 65% reduction in the risk of disease progression compared with immunotherapy alone, but came with significant added toxicity, with serious adverse events in more than half of patients.
Conference discussants flagged that it remains unclear which patients benefit most from the additional burden of an ADC combination, and that a biomarker capable of identifying those patients would be essential.
That uncertainty matters for AZ, which is using a proprietary biomarker strategy in its own Datroway trials in an attempt to carve out a defensible patient population.
Cross-trial comparisons presented at the conference suggested sac-TMT may have an efficacy edge over Datroway, making that biomarker strategy increasingly important to Datroway’s commercial case. Key survival data from AstraZeneca’s own AVANZAR study are not expected until the second half of 2026.
AZ also presented subgroup data from the failed CARES trial of anselamimab in light-chain amyloidosis, a rare condition in which abnormal proteins accumulate in organs.
Despite the overall trial missing its primary endpoint, patients with kappa light-chain amyloidosis showed a 62% reduction in all-cause mortality. Regulators are expected to rule on approval in the second half of this year, and peak sales of around $500 million are forecast if approved.
For Roche, its oral breast cancer drug giredestrant drew mixed commentary.
Conference discussants praised its tolerability and called it the new standard for adjuvant treatment in hormone receptor-positive breast cancer, but cautioned that follow-up data remain immature and that there is no immediate case for changing clinical practice.