The ASCO 2026 annual meeting featured a high-stakes showdown between bispecific antibodies and antibody-drug conjugates (ADCs), two of the most intensely pursued modalities in oncology. Researchers presented comparative data from multiple late-stage trials, aiming to determine which drug class offers superior efficacy and safety across several solid tumor types.
In the bispecific corner, candidates designed to engage two distinct antigens or immune cell receptors showed encouraging tumor shrinkage rates, particularly in non-small cell lung cancer and hematologic malignancies. Meanwhile, several ADCs — which deliver cytotoxic payloads directly to cancer cells — demonstrated durable responses, but at the cost of higher rates of certain toxicities like peripheral neuropathy and ocular adverse events.
Beyond the bispecific-ADC debate, a major scientific highlight was the emergence of a new class of drugs targeting RAS mutations. Historically considered 'undruggable,' KRAS G12C inhibitors have already reached the clinic, but investigators at ASCO 2026 reported first-in-human data for a pan-RAS inhibitor showing objective responses in patients with multiple RAS isoforms. The findings suggest a potential step change in treatment for tumors driven by these mutations.
Another key theme was progress in prostate cancer, where a novel androgen receptor degrader combined with an existing hormonal agent improved radiographic progression-free survival by over 40% compared to standard therapy in a Phase III trial. The data positions this combination as a potential new standard of care for metastatic castration-resistant prostate cancer.
Despite the enthusiasm, experts cautioned that many results remain early and that off-target toxicities for the pan-RAS inhibitor, including skin rashes and gastrointestinal issues, require close monitoring. Long-term follow-up data will be essential to confirm whether these new regimens translate into overall survival benefits.