In this clinical study, a new drug, Budesonid 3 mg effervescent tablet for the preparation of a mouth rinse solution to treat oral chronic GvHD (Graft versus Host Disease) resulting from allogeneic (taken from different individuals of the same species) haematopoietic (blood cell forming) stem cell transplantation (HSCT), is evaluated

INTERVENTION: Product Name: Budesonide Product Code: Budesonid effervescent tablet Pharmaceutical Form: Effervescent tablet INN or Proposed INN: budesonide CAS Number: 51333‐22‐3 Concentration unit: mg milligram(s) Concentration type: equal Concentration number: 3‐ Pharmaceutical form of the placebo: Effervescent tablet Route of administration of the placebo: Oromucosal use CONDITION: Oral chronic graft versus host disease as a complication of haematopoietic stem cell transplantation. ; MedDRA version: 17.1 Level: PT Classification code 10066261 Term: Chronic graft versus host disease System Organ Class: 10021428 ‐ Immune system disorders Therapeutic area: Diseases [C] ‐ Immune System Diseases [C20] PRIMARY OUTCOME: Main Objective: To assess the efficacy of the budesonide 3 mg effervescent tablet rinse versus placebo rinse in decreasing the severity of oral cGvHD and oral cGvHD‐related mouth pain. Primary end point(s): Rate of objective response at the final/withdrawal visit using NIH scale (15‐point Schubert scale) and WHO response criteria. Secondary Objective: To assess the rinse´s safety and tolerability in the form of adverse events and laboratory parameters. Timepoint(s) of evaluation of this end point: Study Visit 2‐12 SECONDARY OUTCOME: Secondary end point(s): Rate of response as defined by NIH ; • Rate of complete/partial response, ; stable disease, progressive disease as ; defined by WHO, ; • Time to initial objective response, ; • Rate of improvement in any of the ; subscores of NIH scale ; • Rate of subjective improvement ; (pain, swallowing, swallow foods or ; liquids), ; • Reduction in pain, ; • Duration of mouth pain and use of ; opiate analgesics following ; treatment, ; • Assessment of salivary secretion, ; • Karnofsky Performance Status, ; • Duration of use of opiate analgesics, ; • Weight loss/gain, ; • Assessment of efficacy by ; investigator Timepoint(s) of evaluation of this end point: Study Visit 1‐12 INCLUSION CRITERIA: 1. Signed informed consent 2. Man or woman between 18 and 75 years of age 3. Karnofsky= 70 4. Oral chronic GvHD after allogeneic haematopoietic stem cell transplantation (cGvHD defined as GvHD present beyond day 100 post‐transplantation) 5. Oral cGvHD confirmed by presence of at least one diagnostic clinical sign of cGvHD or presence of at least one distinctive manifestation confirmed by pertinent biopsy or other relevant tests 6. Oral cGvHD of erosive and/or ulcerative type 7. NIH scale (15‐point Schubert scale) = 3 but at least score 3 (moderate) for ulcers or at least score 2 (moderate) for erythema (lichenoid has to be present in case of absence of ulcers) 8. Resistant oral cGvHD with no oral response defined as the lack of partial response to conventional primary treatment (i.e. systemic prednisone and/or cyclosporine) after 4 weeks or no need for systemic immunosuppression due to oral cGvHD only (mild involvement of 2nd organ al