Drug regulatory authorities in the US have approved once-daily dosing of Kaletra for some treatment experienced-patients.
The Food and Drug Administration (FDA) announced on April 27th that once-daily dosing of Kaletra (lopinavir/ritonavir) was an option for treatment-experienced patients with fewer than three lopinavir-associated resistance mutations. Kaletra once daily is already an option for patients naive to antiretroviral therapy.
Approval for the once-daily dose (800mg lopinavir combined with 200mg ritonavir) was based upon the results of the M06-802 study. This showed that the once- and twice-daily treatment with the drug had comparable safety and efficacy.
A total of 599 treatment-experienced patients were enrolled in this study, and at baseline mean viral load was 4.3 log10 copies/ml.
Patients were randomised to receive either Kaletra once daily in combination with NRTIs, or twice-daily Kaletra (400 mg lopinavir combined with 100mg ritonavir), again in combination with NRTIs.
After 48 weeks, 57% of patients taking Kaletra once daily had a viral load below 50 copies/ml, compared with 54% of those taking twice-daily therapy.
Similar proportions of patients in the two arms of the study experienced virologic failure (22% vs 24%), and discontinued because of adverse events (13% vs 12%).
CD4 cell count increases were similar in the two study arms.
Diarrhoea, a common side-effect of protease inhibitors, was reported by 50% of those taking once-daily Kaletra compared to 39% of those taking the twice-daily dose.
Although similar proportions of patients taking once- and twice-daily doses of the drug achieved an undetectable viral load, the FDA has cautioned that patients with three or more lopinavir-associated resistance mutations should not be treated with the once-daily dose of the drug.
These resistance mutations are L10F/I/R/V, K20M/N/R, L24I, L33F, M36I, I47V, G48V, I54L/T/V, V82A/C/F/S/T, and I84V.
Approval for once-daily use extends to both the tablet and liquid formulations of the drug.
However, the FDA stressed that Kaletra once daily is not recommended for paediatric use.