Primary Outcome Measures:
- to determine the rate of complete responses at the end of treatment (including the maintenance phase) and of clinical responses after the maintenance phase, considering the residual debulked tumour (after the induction phase) as the reference point. [ Designated as safety issue: No ]
Secondary Outcome Measures:
- to determine time to tumor progression, treatment tolerability, indinavir pharmacokinetic profile, biological markers of response (ie. angiogenesis and immunoactivation parameters, HHV8 viral load and immune response) [ Designated as safety issue: Yes ]
Drug: Indinavir in association with Vinblastina +/- Bleomicina
Treatment consists in an induction phase where daily Indinavir (800 mg x 2/die, orally) will be combined together with systemic Vinblastine (10 mg intravenously) +/- Bleomycin (15 mg intramuscularly) in cycles administered every 3 weeks. As maximal response will occur, patients will undergo 2 additional Vinblastine +/- Bleomycin (consolidation) cycles upon continuous treatment with Indinavir. This will be followed by a maintenance phase with Indinavir alone (800 mg x 3/die, orally) in responder patients.
It has been recently demonstrated that HIV protease inhibitors (HIV-PI) exert direct anti-angiogenic and anti-tumor actions by blocking endothelial and tumor cell invasion and matrix metalloprotease (MMP) activity. Based on this data, we have started a phase II trial for the treatment of HIV-negative patients with CKS with the HIV-PI Indinavir. Indinavir was well tolerated and induced KS regression/improvement in early-stage disease, and prolonged stabilization in late-stage KS. Response required high plasma drug concentrations indicating a "therapeutic" drug threshold, and was associated with a decrease of circulating endothelial cells (CEC), basic fibroblast growth factor and MMP2 plasma levels. However, large, confluent tumor masses were generally not responsive (Monini et al, AIDS 2009). Thus, advanced KS may benefit at best by treatment with IND upon tumor debulking by conventional chemotherapy.