Ponesimod (PON) is a sphingosine-1-phosphate receptor 1 modulator. Activation of these receptors on cardiomyocytes during treatment initiation cause transient effects on heart rate (HR) and antrioventicular (AV) conduction. The OPTIMUM phase 3 study assessed efficacy, safety, and tolerability of PON and teriflunomide (TER) in relapsing multiple sclerosis.
We report on the cardiac safety profile of ponesimod versus teriflunomide in the phase 3 OPTIMUM study (NCT02425644).
Patients (18-55 years) were randomized 1:1 to PON (20 mg) or TER (14 mg) for 108 weeks. For PON, a gradual 14-day up-titration starting with 2 mg was implemented to address 1st-dose cardiac effects. Cardiac safety was assessed by blood pressure (BP) and 12-lead ECG measurements. Cardiac treatment-emergent adverse events (TEAEs), major adverse cardiovascular (CV) events (MACE; defined as CV death, non-fatal myocardial infarction [MI], and non-fatal stroke), and TEAEs of special interest (AESIs) are reported.
Of 1131 patients who received treatment (PON: n=565, TER: n=566), baseline mean HR was 70.6 bpm (PON), 70.3 bpm (TER), range 45-126 bmp. Cardiac TEAEs leading to treatment discontinuation occurred in 1 (0.2%) patient on PON (cardiomyopathy) and 2 (0.4%) patients on TER (1 atrial fibrillation, 1 coronary artery insufficiency). No MACE were reported on PON; 3 MACE occurred on TER. HR and rhythm AESIs were reported in 29 (5.1%) PON patients vs. 24 (4.2%) TER patients. Incidence of HR and rhythm AESIs on Day 1 in the PON group (2 mg) was 2.1%, and included bradycardia (HR<50bpm) in 0.7% and 1st degree AV block in 0.5%; vs. 0.4% in TER. Max mean reduction in HR from pre- to post-dose on Day 1 was observed at 2h post-dose for PON at -8.7bpm compared with -1.7bpm for TER. On Day 1, 3 patients on PON had post-dose asymptomatic HR≤40bpm, all had pre-treatment HR<55bpm. On Day 1, new ECG findings of sinus bradycardia was 20.0% in patients at risk for symptomatic bradyarrhythmia, compared to 3.0% (all asymptomatic) in patients who were not at-risk. The up-titration was not associated with clinically significant bradyarrhythmia events; none were serious or leading to discontinuation of treatment, no 2nd degree or higher AV blocks were reported.
In the 2-year OPTIMUM study, PON treatment was not associated with an increased risk for major CV events such as MI, stroke, or CV death compared to TER. The up-titration regimen successfully mitigates 1st-dose effects and supports removing the requirement for 1st-dose cardiac monitoring in patients without risk factors of symptomatic bradycardia.