Varenicline plus counseling improved smoking quit rates compared to counseling alone

In a randomized, double-blind trial of Black adults who smoked daily, participants who received varenicline in addition to counseling had significantly higher odds of smoking abstinence after 26 weeks than those who received counseling and placebo.

Adding varenicline to counseling resulted in significant improvement in smoking abstinence compared to counseling and placebo in a recent trial of Black adults who smoked daily.

Researchers conducted the randomized, double-blind, placebo-controlled Kick It at Swope IV trial at a federally qualified health center in Kansas City, Kan. They enrolled 500 Black adults who smoked daily at all smoking levels from June 2015 to December 2017, with final follow-up completed in June 2018. Participants received six sessions of culturally relevant individualized counseling and were randomized (in a 3:2 ratio) to receive 1 mg of varenicline twice daily (n=300) or placebo (n=200) for 12 weeks. The study medication was provided by Pfizer Global Pharmaceuticals and Pfizer Global Medical Grants.

Randomization was stratified by sex and smoking level, with those who smoked lightly defined as having one to 10 cigarettes per day and those who were moderate or heavy smokers defined as having more than 10 cigarettes per day. The primary outcome was salivary cotinine-verified seven-day point prevalence smoking abstinence at week 12. The secondary outcome was seven-day point prevalence smoking abstinence at week 12, with subgroup analyses for light and moderate to heavy smoking. Results were published June 14 by JAMA.

Of 500 participants (mean age, 52 years; 52% women) who were randomized and completed the baseline visit, 260 (52%) were light smokers and 429 (86%) were menthol users. In total, 441 (88%) completed the trial. Treating those lost to follow-up as smokers, researchers found that participants receiving varenicline were significantly more likely than those receiving placebo to be abstinent at week 26 (15.7% vs. 6.5%; difference, 9.2% [95% CI, 3.8% to 14.5%]; odds ratio [OR], 2.7 [95% CI, 1.4 to 5.1]; P=0.002). Participants who received varenicline also had greater smoking abstinence than the placebo group at the end of treatment week 12 (18.7% vs. 7.0%; difference, 11.7% [95% CI, 6.0% to 17.7%]; OR, 3.0 [95% CI, 1.7 to 5.6]; P<0.001).

Abstinence at week 12 was significantly greater for those receiving varenicline compared with placebo among both the light smoking group (22.1% vs. 8.5%; difference, 13.6% [95% CI, 5.2% to 22.0%]; OR, 3.0 [95% CI, 1.4 to 6.7]; P=0.004) and moderate to heavy smoking group (15.1% vs. 5.3%; difference, 9.8% [95% CI, 2.4% to 17.2%]; OR, 3.1 [95% CI, 1.1 to 8.6]; P=0.02), with no significant interaction between smoking level and treatment effect. Medication adverse events were generally comparable between groups, although nausea was reported more frequently in the varenicline group than the placebo group (55.6% vs. 45.9%).

Among other limitations, the generalizability of the findings is restricted by study inclusion criteria, the study authors noted. They added that while the study had ample power to measure statistically significant treatment effects for the full sample at week 26, it may have been insufficiently powered to assess differences between those who smoked lightly versus heavily.

“For too long, Black individuals have been disproportionately recruited by the tobacco industry to replenish their customer base, have too infrequently received evidence-based cessation assistance during health care visits, have had especially great difficulty quitting smoking, and have experienced disproportionately high mortality rates due to smoking,” an accompanying editorial noted.

The study findings, along with other actions like the FDA's plan to ban menthol flavoring in cigarettes and cigars, “begin to address these challenges via the identification of an effective and widely available treatment for Black smokers, innovative health care systems that more equitably provide smoking treatment, and a policy plan to reduce the addictiveness of cigarettes through a ban on menthol flavoring,” the editorialists wrote. “Together these developments hold the promise to meaningfully reduce the use of tobacco and its resulting harms in the Black population.”

Read the lead cover story in the June ACP Internist for tips on how to help more patients quit smoking.