A Multicenter, Double-Blind, Placebo-Controlled, Randomized Clinical Trial of Oral Anticoagulation in Systemic Sclerosis-Related Pulmonary Arterial Hypertension—Results From the SPHInX Study

M Nikpour; A Calderone; SM Proudman; D Hansen; E Gabbay; N Dwyer; G Keir; V Thakkar; PKK Wong; A Keogh; A Burns; D Prior; H Nandurkar; DS Celermajer; J Sahhar; R Buchbinder; W Stevens

Journal article

A Multicenter, Double-Blind, Placebo-Controlled, Randomized Clinical Trial of Oral Anticoagulation in Systemic Sclerosis-Related Pulmonary Arterial Hypertension—Results From the SPHInX Study

M Nikpour, A Calderone, SM Proudman, D Hansen, E Gabbay, N Dwyer, G Keir, V Thakkar, PKK Wong, A Keogh, A Burns, D Prior, H Nandurkar, DS Celermajer, J Sahhar, R Buchbinder, W Stevens

Pulmonary Circulation | Published : 2026

DOI: 10.1002/pul2.70331

Open access

Abstract

The SPHInX study is the first-ever randomized controlled trial (RCT) seeking to inform an area of equipoise regarding the efficacy of oral anticoagulation as adjunct therapy in systemic sclerosis-related pulmonary arterial hypertension (SSc-PAH). The SPHInX study was an Australian multicenter, double-blind Phase III RCT of 1:1 oral apixaban 2.5 mg twice daily versus placebo over 3 years, as additional therapy in patients with SSc-PAH. The primary end-point was time to clinical worsening (TtCW), or death. A sample size of 85 per arm was required to show a two-fold reduction in TtCW. Participants experiencing clinical worsening events continued in the study, allowing for assessment of explorat..

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