Treprostinil sodium (UT-15)

Inhaled Treprostinil in Pulmonary Hypertension Due to Interstitial Lung Disease

Background: No therapies are currently approved for the treatment of pulmonary hypertension in patients with interstitial lung disease. The safety and efficacy of inhaled treprostinil for patients with this condition are unclear. Methods: We enrolled patients with interstitial lung disease and pulmonary hypertension (documented by right heart catheterization) in a multicenter, randomized, double-blind, placebo-controlled, 16-week trial. Patients were assigned in a 1:1 ratio to receive inhaled treprostinil, administered by means of an ultrasonic, pulsed-delivery nebulizer in up to 12 breaths (total, 72 μg) four times daily, or placebo. The primary efficacy end point was the difference between the two groups in the change in peak 6-minute walk distance from baseline to week 16. Secondary end points included the change in N-terminal pro-B-type natriuretic peptide (NT-proBNP) level at week 16 and the time to clinical worsening. Results: A total of 326 patients underwent randomization, with 163 assigned to inhaled treprostinil and 163 to placebo. Baseline characteristics were similar in the two groups. At week 16, the least-squares mean difference between the treprostinil group and the placebo group in the change from baseline in the 6-minute walk distance was 31.12 m (95% confidence interval [CI], 16.85 to 45.39; P<0.001). There was a reduction of 15% in NT-proBNP levels from baseline with inhaled treprostinil as compared with an increase of 46% with placebo (treatment ratio, 0.58; 95% CI, 0.47 to 0.72; P<0.001). Clinical worsening occurred in 37 patients (22.7%) in the treprostinil group as compared with 54 patients (33.1%) in the placebo group (hazard ratio, 0.61; 95% CI, 0.40 to 0.92; P = 0.04 by the log-rank test). The most frequently reported adverse events were cough, headache, dyspnea, dizziness, nausea, fatigue, and diarrhea. Conclusions: In patients with pulmonary hypertension due to interstitial lung disease, inhaled treprostinil improved exercise capacity from baseline, assessed with the use of a 6-minute walk test, as compared with placebo. (Funded by United Therapeutics; INCREASE ClinicalTrials.gov number, NCT02630316.).

Pharmacotherapy for pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a condition associated with substantial morbidity and mortality. Over the last 25 years there has been a significant evolution in the therapies to treat PAH. These therapies are effective for patients with group I PAH and group IV PH [chronic thromboembolic pulmonary hypertension (CTEPH)]. PAH is characterized by an imbalance of nitric oxide, prostacyclin and endothelin levels, and current pharmacotherapy involves these three pathways. Earlier clinical trials involving PAH-specific therapies evaluated improvements in 6-minute walk time as a primary improvement whereas contemporary trials have been larger and focused on morbidity and mortality reductions. While there may be a role for monotherapy in disease management, most patients should be considered for dual or triple therapy.

Treprostinil

One patient taking treprostinil breastfed her infant for one year without any complications. However, until more data are available, treprostinil should only be used with careful monitoring during breastfeeding.

Combination Therapy with Oral Treprostinil for Pulmonary Arterial Hypertension. A Double-Blind Placebo-controlled Clinical Trial

Rationale: Oral treprostinil improves exercise capacity in patients with pulmonary arterial hypertension (PAH), but the effect on clinical outcomes was unknown.Objectives: To evaluate the effect of oral treprostinil compared with placebo on time to first adjudicated clinical worsening event in participants with PAH who recently began approved oral monotherapy.Methods: In this event-driven, double-blind study, we randomly allocated 690 participants (1:1 ratio) with PAH to receive placebo or oral treprostinil extended-release tablets three times daily. Eligible participants were using approved oral monotherapy for over 30 days before randomization and had a 6-minute-walk distance 150 m or greater. The primary endpoint was the time to first adjudicated clinical worsening event: death; hospitalization due to worsening PAH; initiation of inhaled or parenteral prostacyclin therapy; disease progression; or unsatisfactory long-term clinical response.Measurements and Main Results: Clinical worsening occurred in 26% of the oral treprostinil group compared with 36% of placebo participants (hazard ratio, 0.74; 95% confidence interval, 0.56-0.97; P = 0.028). Key measures of disease status, including functional class, Borg dyspnea score, and N-terminal pro-brain natriuretic peptide, all favored oral treprostinil treatment at Week 24 and beyond. A noninvasive risk stratification analysis demonstrated that oral treprostinil-assigned participants had a substantially higher mortality risk at baseline but achieved a lower risk profile from Study Weeks 12-60. The most common adverse events in the oral treprostinil group were headache, diarrhea, flushing, nausea, and vomiting.Conclusions: In participants with PAH, addition of oral treprostinil to approved oral monotherapy reduced the risk of clinical worsening.Clinical trial registered with www.clinicaltrials.gov (NCT01560624).

Treprostinil sodium Pharmacia

United Therapeutics Corp (UTC) is developing treprostinil sodium (Remodulin, UT-15), a stable structural analog of prostacyclin, for the potential treatment of primary pulmonary (arterial) hypertension (PAH), peripheral vascular disease (PVD) and other cardiovascular conditions [327593], including critical limb ischemia (CLI) [412483]. In August 2000, UTC submitted the initial, non-clinical sections of an NDA for the treatment of pulmonary hypertension [378906]. Treprostinil, which had previously been designated as an Orphan Drug, was also awarded Priority Review status by the US FDA in October 2000 [385864], [386271]. In December 2000, UTC agreed with the FDA that the NDA for treprostinil did not need to be presented to the Cardiovascular and Renal Drugs Advisory Committee, which was expected to allow UTC and the FDA to work towards the 6-month Priority Review timeline [393888]. On August 9, 2001, the advisory committee recommended approval of treprostinil and UTC refiled the NDA on the same day [418682]. In February 2002, the FDA issued an approvable letter for treprostinil injection for the treatment of PAH. The FDA proposed drug labeling for PAH consistent with the treatment of both primary and secondary pulmonary hypertension in patients with New York Heart Association (NYHA) Class II-IV symptoms. The approvable letter also stated that the FDA intended to approve treprostinil with a requirement that UTC subsequently conduct a post-marketing controlled clinical trial to verify and further describe the drug's clinical benefit [439278]. In February 2001, UTC submitted a marketing authorization application (MAA) in France for approval of treprostinil for the treatment of PAH. Upon approval of the MAA, UTC planned to file for Mutual Recognition in other European countries and was also preparing similar submissions to non-European countries [391986], [397958]. By early 2001, phase II trials of treprostinil for the treatment of CLI were underway [412483]. In March 2001, the company was planning a phase III pivotal study in late-stage PVD by the end of 2001 [424180]. In April 2000, UTC was issued US-06054486 for the method of treating PVD with treprostinil [364130]. In February 2000, UTC entered into an agreement with Paladin Labs for the exclusive Canadian distribution of treprostinil for the remainder of clinical trials and after regulatory approvals [357302]. In November 2000, UTC and Antigen Pharmaceuticals entered into a strategic alliance for the distribution of treprostinil in the UK and Ireland [390157]. In November 2000, Deutsche Banc Alex Brown predicted a sales potential of US $250 million to US $350 million [418736]. In August 2001, Merril Lynch predicted sales of US $10 million to $20 million in 2002 [420652].