Safety and Preliminary Efficacy of BGP345A in Constipation Due to Opioid-based Medications

Inclusion Criteria: I1. Age over 18 years (limit included), I2. Diagnosed with OIC according to the adapted ROME IV criteria (Mearin F et al, 2016)previously used in clinical evaluation of patients with OIC (Webster LR et al, 2017) andself-reported symptoms assessed by a physician (daily diary check at V1 visit):

• Fewer than three (<3) spontaneous bowel movements (SBMs) per week. A SBM is defined asa bowel movement without the use of laxatives in the previous 24 hours as recorded inthe daily diary.
• And one or more of the following symptoms in at least 25% of bowel movements:straining, feeling of incomplete evacuation, and/or hard/small stools, defined asBristol Stool Scale (BSS) score lower than 3 (<3). I3. With chronic non-cancer pain since at least three months, including the followingindications but not limited to: back-pain, rheumatisms and post-operative pain, I4. Patients received opioids for chronic analgesia (intended treatment ≥6 Weeks) for 1week or more prior to study start and a stable regimen of opioids for 3 or more days beforestudy entry (V0 visit) and during the whole study , I5. Subjects must be willing to discontinue laxative use at screening and only use therescue laxatives permitted throughout the study duration, I6. For women:
• Non menopausal with the same reliable contraception since at least 2 cycles before thebeginning of the study and agreeing to keep it during the entire duration of the study (condom with spermicide gel, any oral contraceptive, intrauterine device, subcutaneouscontraceptive implant, vaginal ring, surgical intervention (bilateral tubal ligationor ovariectomy or hysterectomy), ESSURE system),
• Menopausal without or with hormone replacement therapy, I7. Good general and mental health with in the opinion of the investigator: no clinicallysignificant and relevant abnormalities of medical history or physical examination, I8. Able and willing to participate to the study by complying with the protocol proceduresas evidenced by his dated and signed informed consent form, I9. Affiliated with a social security scheme.

Exclusion Criteria: E1. Involvement in any investigational drug or device study within 30 days prior to thisstudy, E2. Unable to withdraw other OIC treatments (any kind of laxative other than provided inthe study), E3. History of chronic constipation prior to starting analgesic medication or any potentialnon-opioid cause of bowel dysfunction that may be a major contributor to the constipationupon investigator judgment, E4. Surgery planned within the whole study period, E5. Evidence of active medical diseases affecting bowel transit, E6. Antibiotic treatment intake within the last month prior the study start (V0), E7. Unwilling to withdraw probiotic supplements, yoghurts without supplemented bacteria arepermitted, E8. Any history of drug addiction in the past five years, E9. Pregnant or lactating women or intending to become pregnant, E10. Unwilling to maintain food habits and current physical activity for the whole studyduration, E11. With a personal history of anorexia nervosa, bulimia or significant eating disordersaccording to the investigator, E12. Having a lifestyle deemed incompatible with the study according to the investigatorincluding drug and alcohol abuse, E13. Taking part in another clinical trial or being in the exclusion period of a previousclinical trial, E14. Under legal protection (guardianship, wardship) or deprived from his rights followingadministrative or judicial decision, E15. Presenting a psychological or linguistic incapability to sign the informed consent, E16. Impossible to contact in case of emergency.