RE:Full Fostemsavir study dataLots to digest.
A few comments after a quick review.
(1) Viiv was very brief in their discussion of meeting their primary endpoint. That makes me think they were not particularly impressed with the results
(2)Fostemsavir led to 64% having > 0.5 log reduction in HIV RNA at Day 8. Trogarzo achieved that target in 83%. Were Trogarzo patients also sicker at baseline?
(3)Trogarzo achieved mean viral load reduction at 24 weeks of 3.1 log. Fostemsavir was 2.29 log and did not get better even at 48 weeks.
(4) Most patients that received Fostemsavir had at least one adverse event. It seems like Trogarzo is likely better tolerated.
Anyway, I guess we can’t see what proportion of patients in this study were on Trogarzo as well.
I don’t think I see a big threat especially given Trogarzo’s head start.
bfw
SPCEO1 wrote: Here is a link to much more info than was given in the press release:
https://www.clinicaltrials.gov/ct2/show/results/NCT02362503?term=fostemsavir&cntry=US&rank=1§=X543edcba987106#limit
You have to wonder how focused Viiv will be on getting Fostemsavir approved. First, the drug they care most about, because it is a sizable one for them (maybe worth $3-$4 billion in annual sales), is Cabotegravir. By comparison, I would guess Fostemsavir would net them $200 million in sales under a best case scenario (largely because Trogarzo has such a big head start on Fostemsavir and will ahve captured most of the market). I am sure they would like to have those smaller sales too, and especially because they paid $350 million for Fostemsavir and another drug that has already gone by the wayside. But one reason they were likely not more specific is because they want to get the bigger drug approved first and likely don't want to tax either their own internal resources or those of the FDA in any way that would slow the approval process for the bigger drug.
Moreover, when you look at the link above, it looks a whole lot more scary than Trogarzo did. I am not a medical expert but it seems clear to me that Trogarzo has a clear advantage when you look at the results of both drugs. Part of that, however, may be because of the small study the FDA allowed Taimed to do on Trogarzo which meant they could not collect enough data to do as many statistical analyses of it.
I am obviously interested to have someone who is more knowledgeable medically to weigh in on the info in the link (JFM, BFW - I am think of you naturally).
The fact that ViiV is pursuing Fostemsavir still tells us they think there is a decent sized market in MDR. Since Trogarzo has first mover advantage, they must think it is pretty large or they would not pursue it. Remember, ViiV is a very large company and they normally would not be too willing to pursue smaller markets as it just would not move the needle much for them.
There have also been rumors of production problems with Fostemsavir.
The original press release also did not mention the total viral load reduction, which is curious. It also talked about there being no cross-resistance based on in-vitro studies, rather than the human trial results - that is odd. Odder still is there was no late breaker presentation on these results at ID Week this year as there were for Trogarzo's results in the past. It almost seems like ViiV is not trying to draw much attention to the results, which is again, not normal for a drug a company is excited about launching. There was also no independtent doctor quoted in the press release, which is a normal thing that is included in such things.
Fostemsvir might be a future competitor but it is not yet clear it is a significant threat to Trogarzo.
Someone has said maybe TH would purchase Fostemsvir. That seems very unlikely to me but I wonder if TH would even be interested if the price was right. I doubt htey will answer that question when I pose it to them, however.