Replies to post #74325 on Innovation Pharmaceuticals Inc (IPIX)

[DoubleJ23]

CTIX specifically mentions the possibility of a box warning in its SEC documents (I want to say this was revealed last summer). Overall side effects should be greatly reduced as the dose for psoriasis is much lower than what is used for HIV, but the hypersensitivity issue still remains. The box warning is still probable because of the hypersensitivity issue, but Prurisol patients will get a test to determine if they are hypersensitive before the drug is administered (If I recall correctly, dmattingly posted an email from Leo on this very item, I could look it up if you want...). While the test does greatly reduce the incidence of adverse reactions, it does not eliminate it. It will be interesting to see after the trials, whether or not the adverse reactions continue to occur or if the incidence is low enough to not warrant the warning. This will only be knows after trial data is released.

[KMBJN]

The black-box warning for Prurisol would be for hypersensitivity reactions to the drug, for people with HLA-B*57:01, as exists for abacavir.

Basically, everyone needs to be tested for HLA type before they receive Prurisol (abacavir acetate) or Ziagen (abacavir sulfate), since those with HLA-B*57:01 would be more likely to develop a potentially life threatening allergic reaction.

From Wikipedia:

"The mechanism underlying abacavir hypersensitivity syndrome is related to the change in the HLA-B*5701 protein product. Abacavir binds with high specificity to the HLA-B*5701 protein, changing the shape and chemistry of the antigen-binding cleft. This results in a change in immunological tolerance and the subsequent activation of abacavir-specific cytotoxic T cells, which produce a systemic reaction known as abacavir hypersensitivity syndrome.[18]"

Then again, as BK said, maybe the dose of abacavir in Prurisol would be low enough for it to be less of a problem.

I do recall exclusion of HLA-B*57:01 subjects in the Phase I Prurisol study:

"Positive test for HLA-B*5701 allele by certified laboratory"

http://clinicaltrials.gov/show/NCT02101216