biowa,
While perusing the lymphoma posters Saturday morning at the conference, I had the pleasure of meeting and having a nice conversation with Bill Rohn, COO of IDEC. Finding him to be well-informed and well-spoken, I proceeded to unload some of my burning Zev/radioimmunotherapy questions on him, especially those arising from our dosimetry discussion here.
What I found more interesting than the one excluded patient is the fact that dosimetry is being used as a safety screen for inclusion. That should be interesting to finesse with the FDA, "Well, yes we did think it was important to not treat patients in the study with these dosimetry results, but since we only enrolled one patient who it would be a problem..."
I asked Bill what their long-term plan was for use of Indium-labeled antibody and gamma imaging with Zev. He replied that they intend to prove that Zev can be safely administered without it, and that they ultimately intend for 111In imaging to be an available but entirely optional process. He mentioned that there were a few situations where it might still be used, for example, calibration of intentionally myeloablative doses. He mentioned the potential benefits of cheaper and easier Zev administration without the Indium dosimetry, and mentioned that of course the FDA would have to view the data and sign off on this. I was tempted to counter with, "What about the guy you didn't treat?!" but didn't bring it up - I suppose I lack that killer instinct of a real Mike Wallace-style reporter, and anyway I didn't want to risk pissing him off because I had a lot more questions...
Another burning question I've had is, "how does IDEC plan to handle radiolabeling of the antibody once Zev has been approved, will it be done at a central location (as Coulter plans to do) or will it need to be done at local/regional radiopharmacies?" Hadn't been able to find any information from IDEC up to this point on what their plans are for this. I mentioned my speculation that the short half-life of 90Y would prohibit centralized radiolabeling for Zev, and that Coulter might realize a quality-control and ease-of-use advantage here because the long half-life of 131I has allowed them to build a centralized radiolabeling process. Bill responded that Zevalin would be distributed as a kit, and the radiolabeling would be performed at local/regional facilities of the administering clinics. He said that he didn't perceive this as a big issue one way or the other. While I continue to believe that the FDA will be happier with a centralized facility and the quality control that is possible with that arrangement, a couple of other knowledgeable individuals I spoke with at the conference (one MD, one brokerage analyst) apparently agreed with Bill that this wasn't a big deal. This also puts an interesting twist on the ease-of-use equation - we know that dosimetry will render Bex administration more complex and cumbersome for administering clinics, but we should remember that Zev carries the burden of local radiolabeling at those clinics, where Bex will come "pre-mixed".
There's some interesting wording in both the Coulter and IDEC 10K's about orphan status for Bex and Zev in relation to transformed low-grade NHL, so I asked about this as well - you can read some of these statements as suggesting that one of these drugs might get marketing exclusivity for the indication by virtue of being approved first. Bill replied that he did not believe that Bex and Zev would be deemed similar enough for either treatment to block marketing of the other via orphan designation. He mentioned that this applies more toward compounds which are much more similar on a molecular basis. With different antibodies and different radioisotopes, Bex and Zev are quite different in a molecular sense. He mentioned that orphan status was more often useful for the tax breaks it brings than for possible marketing exclusivity.
Like a lot of people I spoke with, I couldn't resist asking him what he thought was going on with the Bex BLA at the FDA. Like most of those I spoke with, he declined to speculate on that...
Cheers,
Gordon |
