680   Kaletra (Lopinavir/ Ritonavir) in HIV-Infected Children at 48 Weeks.

X. Saez-Llorens*¹, C. Renz¹¹, C. Deetz¹¹, P. Jiang¹¹, P. Cahn², A. Violar³, P. Gomez⁴, E. Handelsman⁵, S. Pelton⁶, O. Ramilo⁷, E. Chadwick⁸, S. Arpadi⁹, U. Allen¹⁰, D. Kempf¹¹, R. Bertz¹¹, and E. Sun¹¹.
¹Hosp. del Nino, Panama City, Panama;²Fundacion Huesped, Buenos Aires, Argentina;³Baragwanath Hosp., Johannesburg, South Africa;⁴Princess Margaret, Nassau, Bahamas;⁵Univ. Hosp., Brooklyn, NY;⁶Maxwell Finland Lab., Boston, MA;⁷Univ. of Texas Southwestern Med. Ctr., Dallas;⁸Childrens Mem. Hosp., Chicago, IL;⁹St. Luke's Roosevelt Hosp. Ctr., New York, NY;¹⁰Hosp. for Sick Children, Toronto, Ontario, Canada; and¹¹Abbott Labs., Abbott Park, IL.

Background:Long-term follow-up of Kaletra (lopinavir/ritonavir, formerly known as ABT-378/r) suspension at a dose of 300/75 mg/m²BID in HIV-infected children.

Methods:100 antiretroviral (ARV)-naive and -experienced (exp.) but NNRTI-naïve pediatric subjects ages 6 months to 12 years old were randomized to Kaletra, with naive subjects receiving d4T and 3TC and exp. subjects receiving nevirapine and 1—2 NRTIs.

Results:Three groups of subjects with varying ARV treatment experience were analyzed: 44 naïve (I), 32 NRTI exp. (II) and 24 NRTI + PI exp. (III). Mean % CD4 increase from baseline (and mean % CD4 at Week 48) was 10.3 (21.6) for I, 5.3 (28.6) for II and 6.7 (23.2) for III. By an intent-to-treat analysis, HIV RNA % <400 (and <50) copies/mL were 84 (71) for I, 88 (69) for II and 58 (54) for III at Week 48. Of the two discontinuations prior to Week 48, one (due to pancreatitis) appeared to be related to study drug. The most commonly reported AE of at least moderate severity and probable or possible relationship to Kaletra was rash (2%). No Grade 3 or higher elevations in glucose, triglyceride or cholesterol were observed (NIH Division of AIDS Toxicity Grades). Virologic response with respect to baseline protease genotype and phenotype was similar to that observed in adults. Baseline resistance data was available for 20 of 24 subjects in Group III. Of these, 1 of 3 subjects with >10-fold and 10 of 17 subjects with <10 fold reduced susceptibility (by phenotypic assay) to Kaletra had HIV RNA <400 copies/mL. Results will be updated.

Conclusions:Based on ongoing study results, Kaletra suspension appears to be well-tolerated and associated with antiviral activity in HIV-infected children.