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Varenicline (Chantix) helps French with HIV quit smoking
in 48-week placebo trial
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CROI 2015, February 23-26, 2015, Seattle, Washington
Mark Mascolini
Varenicline (Chantix/Champix) plus counseling proved superior to placebo plus counseling in helping HIV-positive people in France quit smoking [1]. One third of participants randomized to varenicline quit by the end of the 12-week treatment. At 48 weeks the success rate had dwindled to a little over 15% with varenicline, but that result remained significantly better than the abstinence quotient with placebo and counseling.
No one needs convincing that smoking poses a huge threat to the health of people with and without HIV. Patrick Mercie, who presented varenicline trial results for the ANRS, noted that about half of HIV-positive people in Europe smoke, a prevalence higher than in the general population. In the United States, the CDC calculates that 42% of HIV-positive people smoke, compared with 21% of the general population [2]. Varenicline blocks nicotinic acetylcholine receptors and so dampens the craving for nicotine.
Mercie and colleagues conducted a phase 3 trial that enrolled HIV-positive people who smoked at least 10 cigarettes daily and expressed motivation to quit. No one had another current dependency to psychoactive substances, and no one had ongoing depression or a record of suicide attempts. US prescribing information carries a black box warning of "serious neuropsychiatric events," including depression and suicide, in people using varenicline [3].
ANRS investigators randomized participants to varenicline or placebo for 12 weeks. Dosing started with 0.5 mg once daily on days 1 to 3, rose to 0.5 mg twice daily on days 4 to 7, then to two 0.5-mg tablets twice daily through week 12. Participants in both arms received smoke-ending counseling throughout the study. The primary endpoint was self-reported continuous abstinence from week 9 to week 48. Secondary endpoints included continuous abstinence from week 9 to week 12. The researchers confirmed self-reported smoking cessation by measuring exhaled carbon monoxide.
The study took place from October 2009 through January 2014, with 123 people randomized to varenicline and 125 to placebo. After eliminating people who did not start treatment, the modified intention-to-treat (mITT) analysis included 102 people on varenicline and 111 on placebo. Age averaged 46 in the varenicline arm and 44 in the placebo arm: 83% were men, 73% had an undetectable viral load, and median CD4 count stood at 617. These people had smoked for a median of 25 or 26 years, smoking a median of 20 cigarettes daily. More than 80% of participants had tried to quit at least once.
The mITT analysis determined that 34.3% (95% confidence interval [CI] 25.1 to 43.5) randomized to varenicline and 12.6% (95% CI 6.4 to 18.8) randomized to placebo had continuous abstinence from week 9 to 12. Those rates translated into more than tripled odds of quitting in the varenicline group (odds ratio [OR] 3.6, 95% CI 1.8 to 7.2, P = 0.0003). From week 9 to 48, the continuous abstinence rate was 17.6% (95% CI 10.2 to 25.0) with varenicline and 7.2% (95% CI 2.4 to 12.0) with placebo, yielding almost tripled odds of quitting with varenicline (OR 2.8, 95% CI 1.1 to 6.7, P = 0.024).
Proportions of people who maintained an undetectable viral load rose from before baseline to week 48 in both the varenicline group (81% to 87%) and the placebo group (75% to 90%). CD4 counts remained stable through 48 weeks.
Proportions of participants with any grade 3 or 4 adverse event were 25% with varenicline and 13% with placebo, any grade 3 or 4 lab abnormality 4% and 10%, and any grade 3 or 4 drug-related adverse event 10% and 0%. Drug-related grade 3 or 4 psychiatric events affected 6% in the varenicline arm and no one taking placebo pills. Cardiovascular adverse events were rare and evenly distributed between varenicline (6%) and placebo (7%).
Mercie and colleagues concluded that the adverse events observed reflect those expected in the general population using varenicline. The study is limited, they suggested, because it eliminated people with other substance-abuse problems. The researchers concluded that varenicline is "as effective as [an] adjunct to counseling as in the general population." They proposed that varenicline "appears to offer some benefit and should be considered in HIV case management."
A nonrandomized US study compared varenicline with nicotine replacement therapy in 228 people with HIV [4]. Investigators encouraged participants to use varenicline unless they had depression or a history of psychiatric problems. After 12 weeks of treatment and counseling, proportions of confirmed abstainers were 25.6% with varenicline and 11.8% with nicotine replacement (OR 2.54, 95% CI 1.43 to 4.49).
webcast:
http://www.croiwebcasts.org/console/player/25793?mediaType=slideVideo&
References
1. Mercie P, Roussillon C, Katlama C, et al. Varenicline vs placebo for smoking cessation: ANRS 144 Inter-ACTIV randomized trial. CROI 2015. February 23-26, 2015. Seattle, Washington. Abstract 139.
2. Mdodo R, Frazier E, Mattson C, Sutton M, Brooks J, Skarbinski J. Cigarette smoking among HIV+ adults in care: Medical Monitoring Project, US, 2009. 20th Conference on Retroviruses and Opportunistic Infections. March 3-6, 2013. Atlanta. Abstract 775. http://www.natap.org/2013/CROI/croi_21.htm
3. CHANTIX (varenicline) tablets. https://www1.pfizerpro.com/hcp/chantix
4. Ferketich AK, Diaz P, Browning KK, et al. Safety of varenicline among smokers enrolled in the lung HIV study. Nicotine Tob Res. 2013;15:247-254. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3524069/
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