Comments from N Vergel about using these meds in combination:
1- MK 518 (integrase inhibitor) cannot be used yet with TMC 125 ( a non nucleoside) until Tibotec and Merck finish their interaction studies. Too bad it is taking this long!
2- Maraviroc ( a R5 coreceptor antagonist) can only be used for those who have a purely R5 tropic virus. You will need a test to determine that when applying to the expanded access program. Pfizer will cover the cost for that test. If you have a R5/X4 mixed or dual tropic virus, or a X4 only virus, you will not be allowed into the program. It is impossible to predict wich tropism your virus will have without testing for it, although people with longer term infection tend to have more X4 tropic virus than those in earlier stages.
3- Try to start 3 active meds when you start any new regimen. Ask your doctors to show you your genotype and/or phenotype test and discuss it with her before proceeding. Try to avoid a two active agent combo if you can wait for three. Be on the look out for any baseline resistance to Aptivus or Prezista. Just because you have never taken those two meds, it does not mean that you do not have resistance to them. Message: a new medication may not necessarily mean it is an “active” medication to fight your virus.
4- TMC 125 cannot be used with Aptivus ( a protease inhibitor). Also, you cannot use TMC 125 with Sustiva or Viramune. There is another product coming this year in phase III called TMC 278 (another non nuke) that may be more effective than TMC 125. If you develop resistance to TMC 125 , you may have diminished response to TMC 278. Keep that in mind in deciding when to start or to wait for later if you can.
5- Maraviroc can be used with both MK 518 and TMC 125. The Maraviroc program will start next month (Feb) in many countries
6- Other medications that can be used with either of these meds are: Fuzeon, Prezista, Aptivus, all nucleosides, and non nukes (for non TMC 125 combos)
7- MK 518 blood levels can increase when used with Reyataz. No one knows if this translates to a more durable response in the long term (after 48 weeks). So far, MK 518 seems to have a very good side effect profile
8- Remember that doctors and research nurses do not get reimbursed for their time when helping you get into most expanded access programs. Some doctors chose not to participate because of that. Try to find a doctor who has the manpower needed for all the paperwork required for these programs. It is difficult sometimes to find out who these doctors are since most companies refuse to list them to avoid upsetting non-EAP doctors. Pfizer and Tibotec are now doing a little better when it comes to helping cover manpower costs associated with these pre-approval expanded access programs than Meck is.
This info is from the FDA:
MK-0158, TMC125, and Maraviroc Now Available Through Expanded Access
In the September 15, 2006, At-a-Glance newsletter, AIDSinfo highlighted two anti-HIV medications available through expanded access. The Food and Drug Administration’s expanded access programs provide patients with limited treatment options a way to add investigational medications to their treatment regimen. Now, in addition to MK-0158 and TMC125, a third anti-HIV medication has been made available through expanded access: maraviroc.
Maraviroc is a CCR5 antagonist. CCR5 is a protein found on the surface of certain immune cells that the HIV virus uses to enter the cell. CCR5 antagonists inhibit HIV from entering immune cells.
MK-0158, TMC125, and maraviroc are expected to be approved in 2007. Learn more about the Food and Drug Administration’s expanded access and expedited approval processes for HIV/AIDS therapies.