Objective: To assess the efficacy and safety of all-trans-retinoic acid (ATRA), a retinoid with antitumour activity that inhibits in vitro the growth of Kaposi's sarcoma cells, in patients with low-risk AIDS-associated Kaposi's sarcoma.
Design: Non-randomized phase II study, using a group sequential procedure to determine whether the response rate to ATRA was above 10%.
Setting: Nine referral French centres.
Patients: Twenty HIV-seropositive men with CD4 cells > or = 200 x 10(6)/l, low-risk Kaposi's sarcoma [T0I0S0 according to the classification of AIDS Clinical Trials Group (ACTG)] not previously treated with systemic anti-Kaposi's sarcoma agents, and with at least four measurable lesions were included.
Interventions: ATRA was given orally 45 mg/m2 daily for 12 weeks.
Main outcome measure: Tumour response evaluated according to ACTG criteria.
Results: Nineteen patients were evaluated for response: partial response, stabilization and progression were found in eight (42%), seven (37%), and four (21%) patients, respectively. Gradual flattening and lightening of lesions was observed in responders after at least 2 months of ATRA. All patients with partial response at week 12 pursued ATRA for another 15+/-7 weeks. Further improvement was observed in six patients. Median duration of response was 332 days. Cheilitis, transient headaches and skin dryness were the main toxicities noted. No significant changes in HIV viral burden or serum interleukin-6 pathways were observed.
Conclusions: ATRA is well tolerated and effective enough in Kaposi's sarcoma patients to warrant further evaluation.