The modern pipeline of antibody-drug conjugates in solid tumors has largely moved away from older microtubule toxin payloads (like DM4 or MMAE). The majority of ADCs currently in development, and the focus of clinical excitement, utilize camptothecin-based payloads, specifically topoisomerase-1 inhibitors like deruxtecan, reflecting a major technological evolution in the field.

When sequencing antibody-drug conjugates, clinical experience suggests that resistance to the chemotherapy payload is a primary driver of failure. Therefore, oncologists tend to avoid using another ADC with the same payload consecutively, preferring to switch both target and payload if possible.

Gilead consistently demonstrates an appetite for high-risk, novel science. From pioneering CAR-T (Kite) and new ADCs (Trodelvi) to its latest T-cell engager deal, the company's acquisition history signals a clear preference for cutting-edge platforms rather than safer, later-in-class assets.

To mitigate the severe toxicity of promising pan-RAS inhibitors, companies are adopting antibody-drug conjugate (ADC) technology. This marks a strategic expansion for ADCs, moving beyond traditional cytotoxic chemotherapy payloads to delivering highly specific targeted therapies, aiming to improve the therapeutic window of potent new drug classes.

J&J's $1B cash acquisition of Firefly underscores the high value placed on the Degrader Antibody Conjugate (DAC) platform. The core appeal driving these deals is 'double specificity'—the antibody targets a cell and the degrader payload targets a specific protein within it. This dual-targeting mechanism promises enhanced efficacy and safety, attracting major pharma investment.

The primary reason Antibody-Drug Conjugates (ADCs) stop working is payload resistance, a shift from the traditional belief that failure stems from tumors losing the target antigen. This insight drives development of multi-payload ADCs to overcome this resistance mechanism.

Beyond sheer scale, China's innovation leads in complex, next-generation drug modalities like ADCs and bispecifics. Chinese biotechs now account for roughly one-third of the global Phase 1 and 2 pipelines for these advanced therapies, indicating a shift from iteration on established targets to leadership in new technology platforms.

The Simcirzyming and Ipsen deal, valued up to $1.06 billion for a preclinical antibody-drug conjugate (ADC), shows the immense value of promising therapeutic modalities. Technologies like ADCs with features like 'enhanced tumor penetration' can secure massive bio-dollar deals long before human trials, signaling intense competition for next-generation oncology assets.

Despite prior speculation of a slowdown, the prominence of Antibody-Drug Conjugates (ADCs) in first-in-human trials at ASCO is "skyrocketing." The volume of new ADC trials now nearly equals that of small molecules and far surpasses traditional monoclonal antibodies.