This is a single centre, open label, randomized, two-treatment, two-period, two-sequence, single dose crossover food effect study in 18 subjects. The subjects will receive the study medication under either fed or fast during each treatment period.

The present study will be conducted in healthy male volunteers. A single oral dose will be administered to the subject in each treatment period (under either fasting or fed state). Each treatment period will be separated by at least 7 calendar days. Post dose PK blood samples will be collected in each treatment period to evaluate the food effect on bioavailability of RP6530. The safety and tolerability of single dose will also be evaluated.

Inclusion Criteria:

• Healthy male volunteers; aged 18 to 45 years;
• Body mass index (BMI) between 18.0 and 30.0 kg/m2 inclusive, weight ≥ 50 kg;
• Non- smokers or ex-smokers;
• Able to give informed consent.

Exclusion Criteria:

• Subjects with evidence or history of clinically significant disease;
• Positive results to HIV Ag/Ab Combo, Hepatitis B surface Antigen (HBsAG (B) (hepatitis B)) or Hepatitis C Virus (HCV (C)) tests;
• Subjects who have received any investigational drug in the previous 28 days;
• Subjects participated in a study with PI3k inhibitors at least once in past year;
• Subjects who have received drugs metabolised by CYP3A4 enzyme in the previous 28 days.

18 healthy volunteers were enrolled to get at least 12 completed subjects to demonstrate food effect.

• Safety population included all participants who received at least 1 dose of study drug.
• PK population included all the participants who provided PK in both period.

Day 1 to Day 7

Subjects who entered the study and received at lease one of the treatments under study.

2 HV dropped in 2nd period in "Fast Condition first, then Fed Condition sequence" similarly, two HV dropped in second period in "Fed Condition first sequence", therefore each treatment had 16 HV for AE evaluation; Fasting 16 and fed 16