Treprostinil diethanolamine

Treprostinil diolamine sustained release (UT-15C SR) is being evaluated as an oral therapy for pulmonary arterial hypertension. This study evaluated the pharmacokinetics (PKs) of treprostinil following administration of UT-15C SR in subjects with end-stage renal disease (ESRD) compared with healthy subjects with normal renal function (NRF) and the effect of hemodialysis on the PK parameters of treprostinil. Eight ESRD subjects (requiring dialysis, mean creatinine clearance = 11.5 mL/min) received 2 single doses of 1 mg of UT-15C SR (separated by 2 weeks), with the first dose given immediately after dialysis and the second given 4 hours before the start of dialysis. Eight NRF subjects received a single dose of 1 mg of UT-15C SR. The median Cmax, AUC0-inf, and t1/2 of treprostinil were 680 pg/mL, 3240 hours pg/mL, and 2.35 hours, respectively, in ESRD subjects dosed after dialysis and were 551 pg/mL, 3152 hours pg/mL, and 2.05 hours, respectively, in ESRD subjects dosed before dialysis. In comparison, corresponding values were 730 pg/mL, 3726 hours pg/mL, and 3.54 hours, respectively, in NRF subjects. UT-15C SR of 1 mg was well tolerated by NRF and ESRD subjects. The most frequent adverse event was headache and nausea. There was no substantial difference in treprostinil PKs between ESRD and NRF subjects following administration of UT-15C SR tablets. Hemodialysis did not have clinically important effect on treprostinil PK in ESRD subjects.

Treprostinil diethanolamine is an innovative salt form of the prostacyclin analogue, treprostinil sodium, developed as an oral sustained release (SR) osmotic tablet. The availability of a formulation permitting convenient systemic delivery might have applicability to scleroderma vascular complications. We evaluated pharmacokinetics and perfusion in scleroderma patients with digital ischemia following escalating twice-daily doses of treprostinil diethanolamine SR.

Scleroderma patients with digital ulcers were enrolled in this dual-center, open-label, phase I pharmacokinetic study. Drug concentrations and perfusion, quantified by laser Doppler imaging, were measured over 12 hours at the 2 mg and 4 mg (or maximally tolerated) doses. Pharmacokinetic parameters were determined from individual plasma concentration versus time profiles using non-compartmental analysis methods. Digital perfusion and skin temperature were modeled as a function of log-transformed drug concentration and other covariates by performing repeated measures analyses using random effects models.

Nineteen scleroderma patients (84% female, 53% limited scleroderma) received treprostinil diethanolamine SR with dose titration up to 4 mg twice daily as tolerated. Peak concentrations (mean maximum plasma concentration (Cmax) = 1,176 and 2,107 pg/mL) occurred approximately 3.6 hours after dose administration, and overall exposure (under the plasma concentration-time curve from time 0 to 12 hours post dose (AUC0-12) = 7,187 and 12,992 hr*pg/mL) was linear between the 2 mg and 4 mg doses. Perfusion and digital skin temperature were positively associated with log-transformed plasma concentration at the 4 mg dose (P = 0.015 and P = 0.013, respectively). The most frequent adverse events were similar to those seen with prostacyclin analogues.

Oral treprostinil diethanolamine was effectively absorbed in patients with scleroderma. Drug administration was temporally associated with improved cutaneous perfusion and temperature. Treprostinil diethanolamine may provide a new therapeutic option for Raynaud's phenomenon and the peripheral vascular disease of scleroderma.

ClinicalTrials.gov NCT00848939.