A single-center, open-label, randomized, two-period, two-treatment, crossover study in healthy male subjects to demonstrate bioequivalence of 1600 mcg selexipag administered as eight tablets of 200 mcg (reference drug) or as single tablet of 1600 mcg (test drug)

The research medication is a medication under development for the treatment of
pulmonary arterial hypertension (PAH)

- To demonstrate bioequivalence of test drug and reference drug
- Safety and tolerability
- Investigate phamacokinetic properties of selexipag and its metabolite

This is a prospective, single-center, open-label, randomized, two-period,
two-treatment, crossover, multiple-dose, up titration, phase 1, bioequivalence
study.

The study will start with a screening At the screening a physical examination
will take place and a few other standard medical assessments will be performed
(Vital Signs, ECG). Furthermore a blood and urine sample will be taken for
laboratory tests and an alcohol breath test and drug screen will be done.
During the stay in the clinic and ambulant visits the subject will receive the
study medication and on several time points blood will be taken. The subjects
will be asked for possible side effects on a regular basis. Furthermore several
safety assessments will be done frequently

Finally a follow up visit will take place

Data from Phase I studies with selexipag indicated that multiple doses up to
1600 µg bid were well tolerated. In a phase 2a study selexipag was well
tolerated and the safety profile was in-line with the expected pharmacologic
effect.
Reported side effects in previous studies were headache, dizziness, diarrhea,
nausea, vomiting, jaw pain, pain in extremity, myalgia,
arthralgia, flushing and cough.

The blood collection may cause discomfort or bruising. Occasionally, fainting,
an infection at the blood sampling site, bleeding and blood clot formation can
occur.