study on analgesia of gic-1001 & gic-1002 on visceral pain, rectal sensory threshold using the barostat method

Conditions: Pain; Cancer; Colonic Disease

Summary: this study evaluates colonic analgesia by comparing two novel formulations, gic-1001 and gic-1002 with placebo using a barostat distender. the healthy male and female volunteers randomized to one of 5 possible treatments will be exposed to rectal distension following a 3-day treatment tid. the barostat methodology is a well-established and validated way to assess visceral pain. visceral pain will be evaluated during exposure to varying distender pressures using a visual analog scale.

the objectives of this single center, randomized, double-blinded, placebo-controlled phase i clinical study include the evaluation of visceral pain intensity under rectal distension following the oral administration of either of two doses of gic-1001 or of either of two doses of gic-1002, equimolar to the first formulation, or of placebo in 90 healthy subjects. the barostat intra-balloon pressure required to elicit pre-defined rectal sensory symptoms (i.e. first sensation, need to defecate, urgency to defecate and pain) will also be determined. rectal sensory symptom ratings and rectal compliance under increased rectal distension will also be evaluated. the contribution of hydrogen sulphide (h2s) to the colonic analgesic activity of gic-1001 by comparison to that of gic-1002 will be evaluated following steady state pharmacokinetic analysis. to further comprehend the non-linear, u shape dose response curve observed with gic-1001 in a previous phase ii a trial. finally, the safety of gic-1002 in healthy volunteers will also be evaluated.

Eligibility criteria:
inclusion criteria: * male or female volunteer * a female volunteer must meet one of the following criteria: participant is of childbearing potential and agrees to use one of the accepted contraceptive regimens from at least 28 days prior to the first dosing, during the study and for at least 30 days after the last dosing or participant is of non-childbearing potential, i.e. surgically sterile or menopausal (at least 1 year without menses) * age between 18 to 65 years * 35.00 kg/m2 ≥ body mass index ≤ 18.50 kg/m2 * light-, non- or ex-smokers. a light smoker is smoking 2 cigarettes or less per day for at least 3 months before day 1. an ex-smoker is someone who completely stopped smoking for at least 6 months before day 1 * barostat naive or no barostat experience in the year preceding screening * clinical laboratory values within the laboratory's stated normal range; or without any clinical significance * have no history of clinically significant diseases or evidence of clinically significant findings on physical exam and/or clinical laboratory tests * have a normal anorectal area, confirmed by entry digital rectal exam (dre) and * signed dated informed consent form by subject exclusion criteria: * pregnant or lactating females * history of significant hypersensitivity to trimebutine, to sulfur-containing drugs or any related products (including excipients of the formulations) as well as severe hypersensitivity reactions (like angioedema) to any drugs * presence of significant gastrointestinal, liver or kidney disease, or any other conditions known to interfere with the absorption, distribution, metabolism or excretion of drugs or known to potentiate or predispose undesired effects * diagnosis of inflammatory bowel disease or irritable bowel syndrome * criteria for functional bowel disorder (i.e. functional constipation, functional diarrhea and ibs) or abdominal pain, as reported by questionnaire * known history of rectosigmoid disease * abnormal anorectal findings during entry dre * history of abdominal surgery (except appendectomy or cholecystectomy) * history of gastrointestinal obstruction, any rectal or colon surgery * known presence of piles or fissures, peri-anal pathology or any other rectal abnormalities * female subjects with history of gynecological surgery (˂ 10 years prior to screening or 1 year for tubal ligation or hysterectomy) * known history of, or risk factors for pelvic floor injury * history of significant gastrointestinal, liver or kidney disease, or surgery * presence of significant cardiovascular, pulmonary, hematologic, neurological, psychiatric, endocrine, immunologic or dermatologic disease * suicidal tendency, history of or disposition to seizures, state of confusion, clinically relevant psychiatric diseases * presence of out-of-range cardiac interval (pr \ 220 msec, qrs \ 119 msec and qtc \> 450 msec for males and \> 460 msec for females) on the screening elcetrocardiogram (ecg) or other clinically significant ecg abnormalities * use of cysteine, methionine, and other sulfur-containing amino acid supplements in the previous 7 days before day 1 of this study; * light-smoker who smokes cigar or is unable to refrain from smoking in the 7 days prior to the housing period and during the housing period of the study * known presence of rare hereditary problems of galactose and/or lactose intolerance * maintenance therapy with any drug or significant history of drug dependency or alcohol abuse (\>3 units of alcohol per day, intake of excessive alcohol, acute or chronic) * any clinically significant illness in the previous 28 days before day 1 of this study * use of any enzyme-modifying drugs, including strong inhibitors of cytochrome p450 (cyp) enzymes and strong inducers of cyp enzymes in the previous 28 days before day 1 of this study; * regular consumption of any supplement related to bowel movement in the previous 28 days before day 1 of this study * positive urine screening of alcohol and/or drugs of abuse * positive results to hiv ag/ab combo, hepatitis b surface antigen (hbsag (b) (hepatitis b)) or anti-hepatitis c virus (hcv (c)) tests * females pregnant according to a positive serum pregnancy test; * subjects treated with any investigational product in the previous 28 days before day 1 or who have already participated in this clinical study; * prior donation of 50 ml or more of blood in the previous 28 days before day 1 * prior total donation of 500 ml or more of blood in the previous 56 days before day 1

Keywords: rectal distension rectal compliance visceral pain pain intensity barostat distender vas (visual analog scale) rectal sensory threshold analgesia trimebutine pain management peripheral colon cancer h2s (hydrogen sulfide)