Viracept's market share increased to 37.7% in December, while Crixivan market share was 31. 6% in December, based on IMS Drug Distribution Data, which surveys monthly manufacturer sales to all channels. Also confirmed in Lehman report that Joe E. just posted.
As far as your comments:
<<Apparently, there's a lower rate on Roche sales of their own PI, a higher rate on Roche sales of Viracept, and they pay AGPH the greater of the two.>>
I believe the arrangement is that Agouron gets royalties on whichever protease inhibitor sells more, and the larger the difference, the higher the royalties, an unusual arrangement, but it seems like that is more favorable for Agouron. L. Moss on AOL pointed out what the royalty arrangement was and IR confirmed it.
Also Roche did not 'choose' to present data comparing Saquinavir to Crixivan, that is the way the European CHEESE study was designed originally, to compare the two protease inhibitors. Not too many companies would pass this opportunity to issue a press release to that effect, especially when the results showed such an increased rate of recovery of CD4 cells with Fortovase compared to Crixivan, at least in that study.
As far as being worried about Fortovase being 'better,'
look at the data at a new web site: natap.com which is still under construction.
Check 'What's New' and look at the index for Fortovase.
It all depends which particular study you look at.
I am sure you noticed that Vertex chose to issue a press release which compared a very small study of different protease inhibitors in groups of only 5 or 6 patients, even though the abstracts at the retro meeting seemed to include data with more patients.
Study NV 15355:
Comparing New Fortovase to Old Saquinavir HGC
16 week analysis of 48 week data, Saq +2 nrti's
Fortovase Saquinavir
Baseline N 81 90
Baseline CD4 448 408
Baseline viral load, 63,000 63,000
CD4 increase 16 weeks +97 +115
HIV RNA <400 80% 43%
HIV RNA <50 copies 46% 28%
HIV RNA decrease <400 -2.0 log -1.6 log
HIV RNA <50 copies -2.5 log -1.8 log
SUN STUDY
Fortovase+AZT/3TC
This is an open-label, non-comparative examination of the triple regimen of saquinavir SGC (soft-gel capsule, Fortovase}, plus AZT and 3 TC.
42 treatment-naive individuals
Mean baseline, HIV RNA 4.8 log 10, 63000 range
Mean CD4 419 cells
The study is ongoing and the following data is preliminary.
The investigators reported that after 20 weeks:
-the reduction in viral load was 3.34 log (range: -4.5 to 2.2 log). for 23 patients that could be evaluated.
-91% were <400 copies/ml (undetectable)
-60% <20 copies/ml.
CD4 increase +259 from baseline of 419 cells
-19/42 participants had withdrawn from the study by week 20 and were not included in the analysis. Two withdrew due to adverse events, 3 due to non-compliance, 4 due to refusal of treatment, 6 lost to follow-up, and one missed the week 16 visit.
The most frequent side effects related to study drug (>5%): nausea, vomiting, diarrhea, and headaches.
Lab abnormalities:
One person had a grade III AST/ALT (liver function tests) at week 2 which resolved after discontinuing study treatment.
One person had a grade IV AST/ALT at week 12 associated with acute hepatitis A.
One person had a Grade III AST/Grade IV ALT at week 20 associated with acute hepatitis A.
An approximate 20% incidence of diarrhea has been reported associated with saquinavir SGC in a different study.
The European data that Agouron reported is more comparable to the data from the CHEESE study.
Three 24-week studies were designed to assess BID regimens of VIRACEPT in combination with two nucleoside analogs.
46 patients
Mean viral load - Baseline 4.9 log10
mean CD4+ cell count -Baseline 346 cells/mm3.
Thirty-six patients received:
1250mg VIRACEPT + d4T + 3TC BID
1250 mg Viracept +AZT/3TC BID
10 patients received:
1000mg VIRACEPT+ AZT + 3TC. BID
After 24 weeks of therapy:
93% (14/15) of patients who received the 1250mg VIRACEPT BID regimen and
10/10 at 1000mg VIRACEPT BID regimen
had viral loads below the limit of detection (<400 copies/ml).
Of these patients with HIV RNA below the standard assay limit of detection,
100% (12/12) of those receiving 1250mg BID and
70% (7/10) of those receiving 1000mg BID were also below the limit of detection of an ultrasensitive assay (<50 copies/mL).
Upon completion of the 24-week study, patients who were on the 1000mg BID VIRACEPT regimen will be increased to 1250mg BID.
The BID regimens were well tolerated.
Further data from the SPICE study in Europe, in patients na‹ve to protease inhibitor and reverse transcriptase therapy: At 24 weeks:
100% of patients on Saquinavir and Nelfinavir plus two non-nucleoside reverse transcriptase were undetectable using the ultrasensitive assay <50 copies
For experienced patients, 86% were undetectable <400 copies/ml, and 75% were undetectable <50 copies.
This combination demonstrated very robust viral load suppression in pretreated and na‹ve patients.
Both Viracept and Saquinavir are potent, and in combination, they appear more potent. |
