|JB and Stockdoc, I'd appreciate feedback on this. In post 52373, Stockdoc opined that SGEN’s EV could block SG from getting BTD status, and be a bulwark against SG getting accelerated approval (“If SGEN beats us to that status, then we have no path for AA based on P2 trial”), but I’m not sure that I agree with that. EV had an ORR of 44% and a duration of response of 7.4 months, whereas SG’s last data was 30% ORR and a duration of 11 months. However, as Weatherproof pointed out in his post 52369: "Let's not forget that SGEN's EV trial has a patient exclusion for "Ongoing sensory or motor neuropathy Grade >/= 2." The trial with IMMU-132 has no such exclusion.” |
It turns out that 20 to 24% of the eligible patients have this neuropathy, and thus using some rough “back of the envelope” calculations, if the SG data to be presented at ESMO shows a 30% ORR without excluding those patients, that’s roughly equivalent to EV’s 40% with the exclusion. If SG’s DOR holds up and shows stable disease, I believe that it can still be a candidate for BTD, irrespective of EV’s obtaining AA because SG would not be a “me too” drug. SG could still meet the BTD threshold by “demonstrating substantial improvement on a clinically significant endpoint(s) over available therapies,” in duration of response, fewer side effects, and a better safety profile.
As Cantor Fitzgerald said in August when it initiated coverage: “Sacituzumab’s oppt’y in urothelial cancer largely depends on pivotal readout and market positioning vs Seattle Genetics (SGEN, NC). IMMU's pivotal study in later-line setting is designed to support pot’l accelerated approval. We note that SGEN’s enfortumab vedotin is a formidable front-runner in the same setting; however, our KOL checks suggest that there is no clear winner yet. Sacituzumab’s pivotal interim data and enfortumab’s real-world experience should be key near-term focus as safety profile could emerge as a key swing factor to entitle the preferred treatment choice.”
If the ESMO data really impresses, I think IMMU can make the case for BTD in UTC, and if the CMC issues get resolved for mTNBC, even though SGEN has just filed for AA, what is there to thwart an AA application for SG in the UTC indication? If the UTC data is good enough to warrant BTD, once it is “scrubbed,” couldn’t SG be in the hunt for a successful AA application irrespective of SGEN’s EV?