Is nelfinavir exposure associated with cancer incidence in HIV-positive individuals?

OBJECTIVE: Nelfinavir exhibits potent anti-cancer properties against a range of tumours. However, in 2006/07, nelfinavir supplies were accidently contaminated with a carcinogen. This analysis investigated the association between nelfinavir use and cancer risk in HIV-positive persons.

DESIGN: Observational cohort study.

METHODS: D:A:D study data was analyzed using Poisson regression models to examine associations between cancer incidence and cumulative nelfinavir exposure, current nelfinavir exposure, and exposure to nelfinavir between 1/Jul/2006-30/Jun/2007.

RESULTS: A total of 42,006 individuals (50% white, 73% male) contributed 303,005 person-years of follow-up between 1/Jan/2004-1/Feb/2014. At study enrolment, median age was 40 (interquartile range [IQR] 33-46) years and 8,305 individuals had a history of nelfinavir use (median duration 1.7 [IQR 0.7-3.4] years). During follow-up, nelfinavir was used by 2,476 individuals for a median of 1.7 (IQR 0.7-3.8) years; 1,063 were exposed to nelfinavir between 1/Jul/2006-30/Jun/2007. Overall, 2,279 cancers were diagnosed at a rate of 0.75 (95% confidence interval [95%CI] 0.72-0.78) per 100 person-years. Neither greater cumulative exposure to nelfinavir (adjusted risk ratio [aRR] 0.93 for every additional 5 years, 95%CI 0.82-1.06, p = 0.26) nor current use of nelfinavir (aRR 0.98 vs. other protease inhibitor use, 95%CI 0.68-1.41, p = 0.92) were associated with cancer risk. The adjusted risk of cancer for participants exposed to nelfinavir between 1/Jul/2006-30/Jun/2007 compared to those receiving other treatment over this period was 1.07 (95%CI 0.78-1.46, p = 0.68).

CONCLUSIONS: Nelfinavir use was not associated with a lower cancer incidence than other protease inhibitor regimens. As of Feb/2014, exposure to the 2006/07 contamination of nelfinavir does not appear to be associated with increased cancer incidence.