A Comparison Study of Kaletra Soft-Gel Capsules and Kaletra Tablets in an African American Cohort

The demand for once-a-day easily tolerated therapies is increasing. While Abbott Laboratories 418 study has demonstrated the efficacy of Kaletra® with both BID and QD dosing with capsules, the pill count of QD dosing may decrease its attractiveness for this population. In some patients, issues such as diarrhea, nausea, food restrictions, or the need to refrigerate their medication may also impact quality of life and possibly lead to non adherence and ultimately treatment failure. Moreover, it is believed that the diarrhea associated with Kaletra® capsules may be the result of capsule excipients that are unrelated to the active drug.

Kaletra® has a long track record of being highly potent and not selective for protease inhibitor resistance as evidence by the Phase II Study 720. The results of this study demonstrate that ABT-378/ritonavir therapy is highly potent, durable, and well tolerated when administered concomitantly with two nucleoside analog reverse transcriptase inhibitors to antiretroviral-naïve HIV-1 infected individuals. A high proportion of subjects achieved normal viral suppression (< 50 copies/ml - 78% by ITT). No discontinuations due to study drug -related clinical or laboratory adverse events occurred during the first 48 weeks of study but the most common adverse effect was diarrhea (25%). Given the high oleic content of the capsules, dosing all six capsules at once may cause a "bolus" of this acid leading to increased diarrhea. Because of the viral suppression advantages, there is desire to see if there is a difference in quality of life and tolerability between the soft-gel capsules and the new tablet formulation of Kaletra® which allows for fewer tablets per day and does not include additives possibly associated with increased diarrhea.

Study MOO-267 (PLATO), a multi-center study evaluated and demonstrated improved quality of life when switching from other regimens (efavirenz, nevirapine, indinavir, and nelfinavir) to Kaletra®. Instruments used to measure change in quality of life included the AIDS Clinical Trial Group (ACTG) Symptom Distress Module (ASDM) which measures the presence of bothersome symptoms commonly seen with HIV and ARV treatment; the Medical Outcomes Study-HIV Health Survey (MOS-HIV) which is widely used to evaluate the Quality of Life (QOL) of HIV infected patients; and the Center for Epidemiological Studies and Depression (CES-D), a validated self-reporting questionnaire used as a screening tool for depression.

The hypothesis is that patient's quality of life will improve when switched from Kaletra® soft-gel to Kaletra® tablets. The tablet formulation of Kaletra® will improve quality of life by simplifying current HAART regimens by decreasing pill count, improving tolerability, eliminating food restrictions and the need for drug refrigeration. African-American subjects were selected for this study because they are an understudied population and due to adherence behavior. In reviewing Abbott Study 418 and Study MOO 267 the percent of African-American enrollees accounted for 27% and 15% of the study groups respectively.1,4 In studies where there is an association between socio demographic factors and adherence behavior, the direction is consistent: younger age, non-white race, lower income, lower literacy and unstable housing was associated with non-adherence. Adherence behavior refers to the extent to which patients take their medication as prescribed by their health provider. As stated above, patients who are younger, non white race, lower income and live in unstable housing are less likely to adhere to the prescribed medication regime. It is important to evaluate antiretroviral therapy formulations to validate patient tolerability and acceptance in order to promote drug adherence. This study will compare the tolerability and acceptance of patients on Kaletra® soft-gel capsules with that of Kaletra® tablet formulation utilizing validated instruments as described above.