Revisiting something in an earlier post, perhaps to invite some discussion and thoughts on a particular point...
I've been critical of the arguments attributed to the CLTR shorts so far, seems they like to throw up more garbage than legitimate concerns. I do have a lingering area of possible concern, though, and if I saw the shorts focusing more on the following sort of concern - "Coulter is not going to get the Bexxar label that they want!", I might have more respect for their arguments.
As I see it, we should forget the scare stories about "it's never going to be approved" and "omigod it's radioactive" and the like - as I mentioned in the post that I'm replying to here, transformed low-grade NHL is a life-threatening unmet medical need for which no effective treatment exists, so I just don't see the FDA holding up approval because the hot-vs-cold trial has apparently not been completed. When we have a patient population like this with very little hope, and an investigational agent which studies have shown to be safe and effective for them, questions like those that a hot-vs-cold study would answer are irrelevant for this case, IMO. Transformed lgNHL is not on the Rituxan label at this point, Bexxar does not have to prove anything vs. a cold antibody here.
However, transformed lgNHL is a small piece of the NHL population - for the larger "relapsed or refractory" populations, a "cold" antibody (Rituxan) is approved for use, and it is here that the results of a hot-vs-cold study might become more interesting (I recall that a number of well-informed posters here have asked questions periodically about the hot-vs-cold study, and I suppose that interest has been largely in relation to the relapsed or refractory populations). So it is here that Bexxar must show some benefit versus the currently approved therapies (even if that benefit is simply something like a differing treatment-resistance profile).
I don't think there's much danger that Bexxar will never show treatment benefit for this population - but perhaps the danger we need to consider and be comfortable with is, "does Coulter have enough data right now to ensure that relapsed/refractory ends up on the label as a result of this filing?" A label restricted to transformed lgNHL would represent a big disappointment IMO, one that the stock might take quite awhile to recover from (I think Bexxar would get enough off-label use in other populations to quickly overcome the labeling, but the stock wouldn't recover until the sales numbers started to bear this out).
Consider the following possible sequence of discussions that might occur for the relapsed/refractory labeling:
- Coulter says, "we have better response rates than Rituxan", but the FDA remains agnostic because of the arguments with IDEC regarding definition of response.
- Coulter says, "we have longer duration of remission" (I think this is the strongest point) but perhaps the FDA thinks the sample size in the pivotal trial wasn't large enough.
- Then perhaps it comes down to hot-vs-cold study results to sway the verdict, and the FDA perhaps says, "not enough data, finish this trial first"...
I don't believe that this is the most likely result of the BLA, but I do think it is perhaps a question worth considering. I would be very interested to hear other thoughts and opinions on this - it seems that of the possible CLTR disappointments we may face in the near term, this one may be one of the most likely.
Gordon |
