The decision was taken solely for business/administrative reasons, no safety considerations entered into this. Ongoing randomized patients to complete.

This is a prospective, multicenter, double-blind (DB), controlled, randomized, parallel group comparison Phase 3a study to evaluate the efficacy and safety of new mesalamine suppositories (MAX-002) as compared to placebo and active medicine after 6 weeks of treatment in adults with mild to moderate ulcerative proctitis (UP).

The present study consists of screening period (2 weeks before randomization), DB phase (6 weeks), OL phase (8 weeks) and follow-up visits at Week 3, Week 6 and Week 14. Participants who are eligible will be randomized to receive 1g MAX-002, 1g Canasa® and placebo suppository once daily in the DB phase. Participants who complete or discontinue the study at Week 6 will either receive 1g MAX-002 suppositories on a voluntary basis, standard care treatment as per investigator's discretion or no treatment during the next 8 weeks of the OL phase. Total duration of treatment will be of 14 weeks. Efficacy will primarily be evaluated by percentage of participants who show response as per Mayo DAI Score at Week 6. Participants' safety will be monitored throughout the study.

Inclusion Criteria:

• Participants who are 18 years old or older
• Participants with total Mayo DAI score between 5 to 10 at Screening and participants with score of 2 or more for the rectal bleeding and for the findings of flexible proctosigmoidoscopy or colonoscopy sub-scores of the Mayo DAI
• Participants with confirmed mild to moderate active UP not extending above rectum as evidenced by flexible proctosigmoidoscopy and histopathology assessments
• Female participants of child-bearing age who have negative serum beta-human chorionic gonadotropin (β-HCG) at the time of entry into the study
• Female participants of child-bearing age who use medically acceptable form of birth control
• Participants who are smokers and non-smokers must not change their smoking habits or nicotine use during the DB treatment period
• Participants who are literate and have legal ability to sign informed consent form

Exclusion Criteria:

• Participants with other digestive diseases interfering with the measurement of any sub-score of the Mayo DAI
• Participants with known presence or suspicion of malignant disease of the digestive system or presence or history of neoplasms other than carcinoma in situ of the cervix or basal carcinoma of the skin
• Participants with clinically significant electrocardiographic abnormalities that would compromise its participation in the study
• Participants who are chronically using oral 5-aminosalicylic acid (5-ASA) at a dose greater than 4g daily, change in the oral 5-ASA dosing, or use of any form of rectal 5-ASA formulations during the 30 days prior to randomization
• Participants with significant use of corticosteroids ,immunosuppressant's or biologic response modifiers that may have a therapeutic effect on ulcerative proctitis during the 45 days before the date of consent
• Participants who use any rectally administered medicine during the 30 days prior to randomization
• Participants who have contraindication to the use of mesalamine or suppository vehicle, analgesia, flexible proctosigmoidoscopy or colonoscopy
• Participants who have blood parameters of grade 3 or higher on the common terminology criteria for adverse events (CTCAE) 5-point scale
• Participants with severe renal or hepatic impairment with parameters of grade 3 or higher on the CTCAE
• Participants with clinically significant urinary tract obstruction and history of idiopathic pancreatitis
• Participants with presence of other known clinically significant medical and/or psychological illnesses precluding participation
• Participants who participate in clinical studies other than observational studies during the 90 days before the date of the informed consent form signature
• Participants who are unable or unwilling to complete the follow-up evaluations required for the study

Restrictions may vary in accordance with each agreement that is negotiated with individual investigators. Sponsor will allow publication after multi-center publication has been published or after an agreed period of time if no such multi-center publication is submitted for publication. Sponsor can ask that Sponsor's confidential information be removed from any publication and defer publication for period of time to allow Sponsor to obtain patent or other intellectual property right protection.