Real-world data suggests that using one antibody-drug conjugate (ADC) immediately after another is often ineffective. A potential strategy to overcome this resistance is to administer a different class of chemotherapy before starting the second ADC.

Experts question the efficacy of sequencing ADCs like EV (Nectin-4 target) and DV (HER2 target) because they share the same MMAE chemo payload. Since resistance is often tied to the payload, not the target antibody, switching targets may not overcome resistance, though anecdotal responses have been observed.

The failure of the TROPiCS-04 trial for sacituzumab govitecan may not indicate the TROP2 ADC class is ineffective. Experts suggest problems with dosing and toxicity management (e.g., neutropenia) during the trial could be the real culprit, arguing that the drug class still holds promise.

Rather than moving through distinct lines of therapy, a future strategy could involve an "ADC switch." When a patient progresses on an ADC-IO combination, the IO backbone would remain while the ADC is swapped for one with a different, non-cross-resistant mechanism, adapting the treatment in real-time.

Emerging data shows that a second ADC, particularly one with the same payload, often has limited efficacy. This suggests clinicians must be highly strategic in selecting the first ADC, as it may be their most impactful opportunity for this class of drugs.

The ASCENT-07 trial, while failing its primary endpoint, revealed a promising efficacy signal for its Trop-2 ADC in IHC0 tumors. This finding from a "negative" study directly spurred a new trial, Tropion-Brest-O6, to investigate another ADC specifically in this refined patient population, demonstrating the iterative nature of clinical research.

Despite both being Trop-2 targeted antibody-drug conjugates, Sacituzumab Govitecan and Datopotomab duroxotein have distinct side effects due to different linkers and payloads. Sacituzumab causes neutropenia and diarrhea, while Datopotomab is linked to stomatitis and ocular issues, requiring unique management strategies.

Contrary to concerns about cross-resistance between HER2 antibody-drug conjugates (ADCs), retrospective data shows TDM-1 remains effective after progression on TDXD. This suggests the different cytotoxic payloads are key, allowing for effective sequencing and challenging the assumption that progression on one ADC class member precludes using another.

The differing efficacy and toxicity profiles of TROP2 ADCs like sacituzumab govitecan and Dato-DXD suggest that the drug's linker and payload metabolism are crucial determinants of clinical outcome. This indicates that focusing solely on the target antigen is an oversimplification of ADC design and performance.