Summary

• Pfizer has announced that a late-stage trial in lung cancer for a Seagen-derived ADC, sigvotatug vedotin, has failed.
• There seems to be no difference in survival for patients treated with this one versus standard chemotherapy.
• It was targeting a protein found on the vast majority of non-small-cell lung cancer cells, and the Phase I results looked so good that Pfizer skipped right to Phase III to really get things rolling.
• There are still other clinical trials ongoing with this ADC, and there are certainly other Seagen ADCs in the clinic for Pfizer or heading there. But all this is illustrating that we still don’t know enough about ADCs in general to pick winners.

I’ve written several times here over the years about antibody-drug conjugates (ADCs) (most recently here and here), and it’s a field that has seen some ups and downs. Recent years have been more of