Transitioning Parenteral or Inhaled Treprostinil to Oral Treprostinil Diolamine: Case Series and Review of the Literature

Strategies for optimizing intravenous prostacyclin-analog therapy in patients with pulmonary arterial hypertension

INTRODUCTION

Intravenous prostacyclin-analogs (PCA, e.g. epoprostenol, treprostinil, iloprost) have become an essential part in the therapy of patients with pulmonary hypertension (PH), mainly pulmonary arterial hypertension (PAH). They show considerable differences in pharmacology. A combination therapy including intravenous drugs is regarded as the 'gold standard' in most of PAH patients.

AREAS COVERED

This review discusses and summarizes the studies and concepts on which this therapy is based. To date, intravenous prostacyclin-analogs are mainly administered when standard therapy fails to improve patients to low-risk status. However, preliminary data from uncontrolled studies suggest that an 'upfront triple' therapy including intravenous or subcutaneous prostacyclin-analogs could be preferable in selected patients.

EXPERT OPINION

Various IV PCA have been evaluated in the treatment of patients with PAH. Today, combination therapy is the 'gold standard' for the majority of patients. Intravenous PCA is recommended from functional class III onwards. Timing of its initiation is still a point of discussion. An escalation of therapy to IV or SC PCA is always necessary if a low-risk status cannot be achieved with other targeted therapies. Preliminary data suggest that selected patients could benefit from an 'upfront triple' therapy. Controlled studies on which such recommendation could be based are lacking.

A multicenter retrospective study of patients with pulmonary hypertension transitioned from inhaled to oral treprostinil

Oral treprostinil has recently been shown to delay disease progression in patients with pulmonary arterial hypertension in a long-term outcomes study. The potential advantages of an oral formulation have resulted in patients transitioning from inhaled to oral treprostinil. The current study reports a retrospective analysis of patients who transitioned from treatment with inhaled to oral treprostinil. A multicenter retrospective chart review was conducted for 29 patients with pulmonary hypertension that transitioned from inhaled to oral treprostinil. Data were collected from inhaled treprostinil initiation and patients were followed until discontinuation of oral treprostinil or the end of the observation period. Persistence was calculated using Kaplan–Meier estimates. Prior to transition to oral treprostinil, patients had received inhaled treprostinil for a median of 643 (IQR: 322–991) days and 52% of patients were New York Heart Association/World Health Organization Functional Class III. For patients that cross-titrated between formulations, the median time to complete the cross titration was 24 (IQR: 1–57) days. At 16- and 24-weeks post-transition, oral treprostinil persistence was 86 and 76%, respectively. Persistence was 59% at 52 weeks post-transition. Clinical stability for the majority of patients at first follow-up post-transition was suggested based on available New York Heart Association/World Health Organization Functional Classification. Transitions from inhaled to oral treprostinil appeared safe and tolerable in the short-term. Additional prospective studies are needed to fully evaluate the safety and efficacy of transitions from inhaled to oral treprostinil.

Inpatient Initiation of Oral Treprostinil in an Academic Medical System

PURPOSE

Clinicians may transition patients on parenteral or inhaled prostacyclins to oral treprostinil for ease of use or to avoid adverse effects related to parenteral therapy. However, few data are available to guide these transitions in inpatients. The purpose of this analysis is to describe the inpatient initiation of oral treprostinil at an academic medical system.

METHODS

This is a retrospective cohort analysis of patients newly initiated on oral treprostinil at Cleveland Clinic Heath System from 2015 to 2017. Demographic information regarding pulmonary arterial hypertension (PAH) history and previous PAH therapies were recorded. Outcomes evaluated included doses of oral treprostinil utilized, adverse effects related to therapy, and measures of clinical and functional status before and after the initiation of oral treprostinil.

RESULTS

Overall, 29 patients were prescribed oral treprostinil, of which 15 patients were included in the analysis. Common reasons for initiation of oral treprostinil included disease progression (6, 40%) and patient desire (4, 25%). The median duration of transition/initiation of oral treprostinil was 4 days (range, 3-11 days). Median daily dose of oral treprostinil on day 1 of initiation was 2 mg (0.25-4 mg). By day 7, median daily dose was 15 mg (0.75-27.75 mg). Common adverse effects related to therapy were gastrointestinal (7, 47%) and headache (4, 27%). No patients required discontinuation of oral treprostinil due to adverse effects within 90 days of initiation.

CONCLUSION

Inpatient initiation/transition to oral treprostinil was relatively well tolerated. Future studies should evaluate clinical outcomes surrounding the transitioning to oral treprostinil.

Transitioning Between Prostanoid Therapies in Pulmonary Arterial Hypertension

Background: New oral prostacyclin therapies and prostacyclin agonists have become available for the treatment of pulmonary arterial hypertension (PAH). However, methods for transitioning between oral, inhaled, and parenteral formulations are not well-established, except in the form of case reports and case series. Collectively, these emphasize the lack of a standardized process and approach in transitioning patients between PAH prostanoid therapies. In this case series, we report our experience at an accredited Pulmonary Hypertension center in transitioning between various oral, inhaled, and parenteral prostanoids to offer additional guidance on safe transitions in therapy. Methods: All cases of prostanoid transitions at an accredited Pulmonary Hypertension center from March 2018 to September 2019 were included in this report. The transition approach for each case was developed through a review of the literature, extrapolation of available pharmacokinetic data, and collaboration between pharmacists and clinicians. Results: This case series describes the transition of 3 patients from selexipag to parenteral treprostinil; 1 patient transitioning from parenteral treprostinil to selexipag; 1 patient transitioning from oral treprostinil to parenteral treprostinil; and 1 patient transitioning from inhaled treprostinil to selexipag. Four of the 6 patients presented here were transitioned to an alternate prostanoid on account of clinical worsening, while the remaining 2 patients transitioned due to intolerance of parenteral therapy and poor medication adherence. This case series includes patients with various etiologies of PAH including idiopathic PAH, methamphetamine-associated PAH, and scleroderma-associated PAH. All patients successfully completed each transition without serious adverse events. Conclusions: With the increasing utilization and availability of prostanoids, there is a critical need for a standardized approach in transitioning safely between different formulations without compromising treatment efficacy. In this case series, we present our clinical experiences, guided by available pharmacokinetic data, in transitioning between various prostanoid formulations.

Oral treprostinil use in children: a multicenter, observational experience

Pulmonary arterial hypertension is a progressive, incurable disease that occurs in adults and children alike. Therapeutic options for children are limited and infrequently described, including newer agents such as treprostinil, an oral prostanoid. Herein, we describe the pooled pediatric experience in 28 patients from four pediatric pulmonary hypertension programs over two years. This descriptive, observational study describes the various methods of initiation of oral treprostinil in both prostanoid-naïve patients and those transitioning from parenteral or inhaled prostanoids. The youngest patient was four years old and the smallest weighed 16 kg. We describe adverse reactions and their management. Most patients in this study (27/28) were able to successfully initiate therapy. However, gastrointestinal adverse reactions were common; half of the patients started on this therapy had discontinued it within the two-year study period.