Testing of HIV Protease Inhibitors to Suppress Inflammation and Improve Cardio Pulmonary Hemodynamics in Subjects With Pulmonary Arterial Hypertension

Study Rationale:There is recent evidence that HIV protease inhibitors (HIV-PI) can improve pulmonary hemodynamics in experimental models of pulmonary arterial hypertension (PAH). There is also experimental evidence that both TLR4 and high mobility group box 1 (HMGB1) participate in the pathogenesis of experimental pulmonary hypertension. A recent high throughput screen for inhibitors of HMGB1 induced macrophage activation yielded HIV-protease inhibitors (PIs) as potent inhibitors of HMGB1 induced cytokine production. Based on the experimental evidence we propose a trial to determine whether HIV-PIs will alter the pathobiology of PAH. Study Objectives:The main objective of this study is to determine whether saquinavir and ritonavir (SQV+RIT) which have a well-characterized safety profile in humans will reduce bio markers of inflammation and pulmonary artery pressures in patients with PAH. Study Hypothesis:We hypothesize that the HIV-PI, SQV+RIT, will reduce circulating parameters of inflammation including HMGB1, IL1-beta, IL-6, IL-8, IL-10, TNF-alpha and CRP. Our end points will be changes in these parameters from baseline over the duration of the study.We hypothesize that treatment with SQV+RIT will reduce pulmonary artery(PA) pressure of patients with PAH as measured by echocardiography. Study Design:This is a single center open label phase 0 study to evaluate the effect of SQV +RIT in patients with IPAH. Subjects with IPAH(N=20) will be enrolled into a study, which will be divided into 3 cohorts and entail the administration of HIV protease inhibitors in three doses. The first cohort (n=3) will receive a starting dose of SQV 0.3 mg/kg twice daily in combination with RIT 0.03 mg/kg twice daily. If the first dose is well-tolerated, the second cohort (n= 3 ) with IPAH will be given doses of SQV 3 mg/kg and RIT 0.3 mg/kg twice daily. If the second dose is well-tolerated, the last cohort (n= 14 ) with IPAH will be given doses of SQV 15 mg/kg and RIT 1.5 mg/kg twice