Replies to post #781 on ImmunoGen Inc (IMGN)

[vinmantoo]

As best I can figure it is a combination of the RBC downgrade and the PFS numbers on the patients with prior bevacizumab exposure.

The confirmatory MIRASOL trial has PFS as the primary. In SORAYA the PFS was OK, but better in bev naive patients.

The concern is that the SORAYA trial might have had less bev patients because it required a PARP inhibitor but the confirmatory MIRASOL trial does not require PARPs, so could have more bev exposure.

Yes, that pretty much hits the nail on the head. DewDiligence posted this on the Biotech values board. The Evaluate Vantage discussion is worth the read.

https://investorshub.advfn.com/boards/read_msg.aspx?message_id=168273382

IMGN discussion by Evaluate Vantage:

https://www.evaluate.com/vantage/articles/news/trial-results/immunogens-mirasol-trial-goes-down-wire

The one point is that the independent analysis gave a longer PFS than the investigator, which I have never seen before. I wasn't counting on a single arm approval but thought there was a shot at it. Now it may be more important for the single arm SORAYA trial to get an approval, even a conditional one. The MIRASOL trial is an open label controlled phase III trial but as you point out the primary end point is PFS. Secondary end points are ORR and OS. I wonder how the FDA would respond if the PFS was better for mirvetuximab by some margin but the ORR was really good compared to the SOC as the SORAYA trial data indicated. Definitely having a bit of concern rising. Oh well, it is only money.