This month's edition of Rx Minute focuses on two major new studies. First, we highlight a new study in the Journal of Oncology Practice and the American Journal of Managed Care which found a surprisingly high rate of abandonment of oral anti-cancer drugs, with high cost-sharing as a key driving factor. Second, we recap a new study sponsored by the National Institute of Allergy and Infectious Disease that produced strong evidence that antiretroviral treatments can prevent HIV/AIDS transmissions.
Cancer Drug Abandonment Common
A new study in the Journal of Oncology Practice and the American Journal of Managed Care finds that 10% of cancer patients abandoned their initial prescriptions for oral anti-cancer drugs and another 23% had a delay in initiating therapy. The study examined claims data for more than 10,000 Medicare and commercially-insured patients who initiated anti-cancer therapy in 2007-2009.
Several factors impacted the likelihood of prescription abandonment: high cost sharing, a higher number of other prescriptions, low income, and Medicare coverage (instead of commercial insurance). Patients with cost-sharing over $500 had an abandonment rate of 25%, four times higher than patients with cost-sharing under $100 who abandoned 6% of claims. Seventy-three percent of patients had cost-sharing of $100 or less, but 16% were at the $500 or higher level.
Patients who had more than five concurrent prescriptions were 50% more likely to abandon claims than patients with no other current claims. Lower household income was associated with higher rates of abandonment, with a rate of 11% for incomes below $40,000 and 9% for incomes over $75,000. Finally, abandonment rates were 16% for Medicare claims and 9% for commercial insurance claims.
The authors conclude, "The results of this study highlight the importance of identifying strategies to minimize the impact of high cost-sharing requirements in prescription drug plans so that they do not pose a barrier to access to newer oral therapies for patients diagnosed with cancer, thereby denying patients the potential benefits of these effective agents."
Early HIV Treatment Initiation Reduces the Risk of Transmission
A large new study sponsored by the National Institute of Allergy and Infectious Disease finds that early initiation of antiretroviral treatments (ART) reduces HIV/AIDS transmission by 96%. The international trial, known as HPTN 052, was stopped and unblinded four years early because the findings were so robust.
At 13 sites around the world, the study enrolled 1,763 couples who were serodiscordant, meaning that one partner is HIV positive and one negative. Couples were randomly assigned to two groups. In one group the HIV-infected partner initiated ART treatment immediately and in the other (the deferred group) they waited to begin treatment until their CD4 count fell below 250 cells/mm3 or they had an AIDS-related illness.
In total, 28 new infections were confirmed to have been transmitted from the HIV-infected partners to the non-infected partners. Of those, 27 were in the deferred treatment group and one was in the immediate treatment group.
In addition, there were nearly six times as many cases of extrapulmonary tuperculosis in the HIV-infected partner in the deferred treatment group compared with immediate treatment group.