Alitretinoin gel (0.1%) (9-cis-retinoic acid) is a topical, self-administered therapy approved in the US and some European countries for the treatment of KS. Two double-blind, randomized placebo-controlled trials involving a total of 402 individuals, evaluated 12 weeks of twice-daily alitretinoin gel [55,56]. The response rates in the active arm after 12 weeks were 37% [56] and 35% [55] compared to 7% and 18% in the placebo arms analysed by intention to treat. In both studies,
over 80% of participants were receiving HAART and this did not influence the results. In another study of 114 patients, 27% of treated Selleck AG 14699 lesions responded compared to 11% of the controls [57]. The gel may cause dermal irritation and skin lightening at the application site. Responses are seen even in patients with low CD4 cell counts and typically occur 4–8 weeks after treatment. 9-cis-retinoic click here acid has also been administered orally (and is only licensed in the UK for chronic eczema). In a Phase II study of 57 patients (56 on HAART), the response rate was 19% although the contribution of the HAART is unclear [58]. Vinblastine is the most widely used intralesional agent for KS and responses of around 70% were reported in the pre-HAART era [59,60].
Treated lesions usually fade and regress although typically do not resolve completely. A randomized study in 16 patients comparing intralesional vinblastine or sodium tetradecyl sulfate in the treatment of oral KS demonstrated partial responses in both groups with no significant differences [61]. Intralesional injections of biologic agents such as interferon-alpha have also shown activity, but are infrequently
used now. In one early study of 20 patients, complete responses were observed in 80% of lesions treated with cryotherapy, and the duration of the response was more than 6 weeks. In addition, greater than 50% cosmetic improvement of KS was reported in this pre-HAART era study [62]. Destructive (i.e., CO2 laser) interventions, can have a role. An alternative experimental approach is photodynamic therapy, which is based upon activation by light of a photosensitizing drug that preferentially accumulates in tumour tissues such as KS [63]. A series of 25 patients Sitaxentan with a total of 348 KS lesions received photofrin 48 hours prior to light activation. No patients were on HAART and 95% of the lesions responded to therapy (33% and 63% complete and partial responses, respectively) [64]. Topical halofuginone is an angiogenesis inhibitor that inhibits collagen type-1 and matrix metalloproteinases (MMPs). It was tested in a blinded intra-patient control study for KS, with serial biopsies taken from index lesions [65]. The study was stopped early due to slow accrual, and clinical benefit could not be assessed. To a large extent local therapies for KS have been superseded by the introduction of HAART. Excisional surgery under local anaesthetic is a simple approach for small solitary or paucifocal lesions.