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As new antiretroviral drugs come on the market, one question that clinicians need to face is when and if they should switch their patients to new cART regimens. In this panel, moderated by Dr. Pedro Cahn, Drs. Frank Pallela, Graeme Moyle, & Calvin Cohen discuss many of the issues around regimen switching. Topics covered include; which patients should be switched, how to make decisions about initiating a new drug regimen, and the timing of a regimen switch. They also discuss how switching can affect drug adherence, and the importance of educating patients about the pros and cons of any new therapy.
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Switching HIV Regimens – When, Why, and to What
Pedro Cahn, MD Frank Palella, MD Graeme Moyle, MD Calvin Cohen, MD
Reasons to Switch
• Virologic failure
• There is a beFer treatment with: – Fewer current side effects – Less poten1al for future side effects
Is the Regimen Broken?
• EvaluaKng problems with cART – Are you re-‐assessing side effects? – Looking for new side effects?
• Is a new regimen available?
The decision to prescribe should be an acKve one. Ask yourself “Is this the regimen I would offer to a new pa4ent just walking into my office today?”
Switching Strategies
STRATEGY RESULT
Switching virally suppressed paKents
from Efavirenz (EFV) to a single-‐tablet
regimen containing Rilpivirine (RIL)
• Safe
• Reduces toxicity
NEW FROM AIDS 2012 Switching suppressed paKents from
boosted PI regimen to same single-‐tablet
regimen:
• Preserves viral suppression
• Avoids hyperlipidemia
Switching to a regimen without a dual
nucleoside
• Less data on safety and efficacy
• May not be recommended
Switching with Confidence • When a person has been suppressed < 50 copies/ml
– Li;le replica1on and muta1on – Drugs effec1ve before suppression are s1ll suppressive a@er
– If every drug was ac1ve when you started, than every drug remains ac1ve
BUT – If they were already somewhat resistant, and you switch to a regimen that requires full ac1vity, you won’t have an ongoing suppressive regimen
Who to Switch
• PaKent selecKon is criKcal • Criteria to consider:
– Never failed therapy – No exposure to mono-‐therapy or dual-‐ therapy
– No history of transmi;ed resistance
• Availability of historical genotypes is important in
determining a switching strategy
Switching Trade-‐offs • PaKents may be doing well on their current regimen • Not all switching problems are related to side-‐effects • Regimens need to be simple for paKents to follow • Inform paKents about:
– Poten1al side effects – Changes in dosing schedule – Other requirements for the new regimen
Ask the paKent – “Does this make sense for you?” And remind them that, without a virologic failure, they can always go back if the switch doesn’t work out
Does Switching = SimplificaKon?
• SimplificaKon is a subset – Fewer pills – Less o@en – How medica1on needs to be taken
• By mouth • With food, or certain types of food
• Ensure paKents understand simplificaKon – Need to be clear on pill numbers/dosing 1me
Even a SimplificaKon ConsKtutes a Change
• Re-‐educaKon, re-‐assessment, and re-‐evaluaKon is necessary – Is it making a pa1ent’s life simpler?
– Is it reducing toxicity? – Is it resul1ng in fewer doses or fewer pills? – Is it something the pa1ent will be happier with?
The SWATCH Study
• Randomized, open-‐label, pilot trial
• PaKents randomized to either alternate triple-‐drug regimens every three months or stay on one regimen
• At 48 weeks, the virologic failure rates were: – 4.8/1,000 person weeks in the two standard treatment groups
– 1.2/1000 weeks in the switching group
Source: Mar1nez-‐Picado J et al. Ann Intern Med. 2003;139:81
PotenKal Benefits of Change
• Encourages paKent educaKon • Reinforces adherence • Facilitates conversaKons between healthcare providers and paKents
Error ReducKon • The more pills, and more detailed the medicaKon
schedule, the easier it is to make mistakes
• It is harder to make dosing errors if paKents only need to take a single pill, once or twice a day
• When paKents are taking mulKple pills they may
– Forget pills – Accidentally double-‐up the wrong pills – Think that they can fill one prescrip1on and not another, when finances are difficult
SWITCH-‐ER Study • Randomized, double-‐blind, crossover study in paKents
controlled by EFV – Raltegravir(RAL) twice a day with Efavirenz (EFV) placebo – EFV once a day with RAL placebo – Switch a@er two weeks to alternate regimen
• Outcome – Half preferred twice daily RAL, even though it meant switching from a one pill, once a day regimen, they had previously tolerated well
– RAL significantly improved lipid levels, stress, & anxiety
Source: Nguyen, A. et al. AIDS. 25(12):1481-‐7
It’s Not Always About Less Pills
• SimplificaKon can be: – Gehng rid of a side effect
– Gehng rid of an an1cipated side effect
Monitoring a Switch
• Viral load checks – Standard schedule is fine, if the regimen is just a pill simplifica1on (same drugs, combina1on pill)
– Should be checked at week 4 with a regimen switch • Double check adherence • Make certain that pa1ents are properly following guidelines for taking the pill
ConsideraKons with a Regimen Change
• Increased monitoring – Biologic factors – Pa1ent compliance
• Need for paKent educaKon – Dosing 1me – Restric1ons among meals
Monitoring afer a switch is a good way to make certain that paKents understand instrucKons correctly
One Month Check • Check at week 4 to assess
– Virologic failure – Hepatotoxicity – Nephrotoxicity (some cases) – Adherence
• Then return to a standard follow-‐up schedule
Harm is rare when switching regimens, but it’s beFer to make certain
CD4 Count – A Reason to Switch? • Suppressed paKents who don’t have CD4 improvements – May not be a problem – May have wide range of “normal” CD4 levels* (350-‐1500 cells/ml)
• CD4 increase does not necessarily predict clinical outcomes
• Where are paKents’ CD4 levels stuck? – A very low count might be a reason to switch – With moderate levels, one can wait and see
* Levels are not well assessed in HIV negative populations
Historical Note
Zidovudine (AZT) and tenofovir/dideoxyinosine (TDF/DDI) regimens did impair immunological reconsKtuKon
This is not known to be a concern with “modern” cART regimens
With respect to immune reconsKtuKon, current differences between medicaKons are subtle, and probably not clinical important
What affects CD4 Rise?
• GeneKc environment
• Ongoing immune acKvaKon
• Trials have varying results • Does it really maFer?
CD4 count may not actually significantly impact clinical outcomes
Switching and Aging • Increases in certain health risks are widely associated with age – Cardiovascular disease – Renal disease
• Should consider these factors when looking at side effect profiles of cART drugs
• Greater potenKal for drug-‐drug interacKons – Older people take larger numbers of non-‐HIV medica1ons
When is it Safe to Switch?
• If the regimen you are switching to would have worked before the paKent was suppressed, it should work now
• Switching interval varies by circumstance: – Early toxicity = early switch – Late toxicity = late switch
• Switching to modernize therapy – A@er at least 6 months on previous therapy – With two consecu1ve undetectable viral loads
What about people with long-‐term success on other regimens?
• There is some data which suggests switching may add security in maintaining a long-‐term undetectable viral load
– Par1cularly when switching to a regimen that would not be appropriate for the treatment naïve pa1ent
– Such regimens may work very well in those who have
already been suppressed in the long term
Oh, Brave New World…
• Treatments are: – Increasingly effec1ve – Increasingly safe – Increasingly convenient
• Many good opKons
• MulKple single-‐tablet, fixed dose combinaKons
– Poten1al financial advantage, as well as convenience
Use The Guidelines
• Regimens recommended in IAS/DHHS Guidelines
– Are strongly supported by clinical trials – Are considered to be the best in terms of safety, efficacy, and tolerability
If paKents aren’t on these regimens – ask yourself why not?
DON’T JUST MAKE SURE PATIENTS ARE ON THE
SAME REGIMEN
MAKE CERTAIN THEY ARE ON THE REGIMEN BEST SUITED FOR THEM