PPALM-Palm Oil and Pentoxifylline Against Late Morbidity (PPALM)

Randomised Double-blind Placebo Controlled Phase II Trial of Tocovid SupraBio in Combination With Pentoxifylline (PTX) in Patients Suffering Long-term Adverse Effects of Radiotherapy for Pelvic Cancer

Side effects are common after treatment with radiotherapy for tumours in the pelvis and can affect the way the bowel and urinary system work as well as causing sexual difficulties, skin damage and bone problems. Problems in the bowel, bladder, sexual organs and skin mostly result from thickening of the tissues in response to radiotherapy, a process called "fibrosis". Fibrosis often worsens over time. There has been progress in treating bowel symptoms which usually are the worst problem after radiotherapy. However, even after receiving the best possible treatments, while many patients are better, they are often not cured of all their difficult problems. For some years, it has been hypothesised that if fibrosis could be treated then symptoms would improve. Recent research in laboratory animals has suggested that an effective treatment for radiation-induced fibrosis is combination therapy with a drug called Pentoxifylline together with a nutritional supplement containing gamma-tocotrienol (Tocovid SupraBio), a substance derived from palm oil. Both of these agents are simple to take and side effects are rare. This study will recruit volunteers who continue to have difficult side effects after previous radiotherapy to the pelvis despite receiving the best treatments available from a unique clinic at The Royal Marsden which has pioneered treatment for bowel problems after radiotherapy. Two out of every three volunteers who take part, will be randomly assigned to treatment with Pentoxifylline and Tocovid SupraBio, while one out of three will receive dummy pills. Neither the patients nor the staff assessing them will know which treatment they have been given. Volunteers take the active treatments or dummy tablets for a year and will be assessed regularly while on treatment and for a year afterwards. This study will show whether active treatment is more effective than dummy pills in improving the symptoms caused by radiation-induced fibrosis.

Change at 12 months in rectal IBDQ bleeding score between the two groups in those patients presenting with grade 2, 3 or 4 bleeding.

Change at 12 months in IBDQ faecal incontinence score between the two groups in those patients presenting with grade 1 or greater incontinence.

Tissue samples will be banked until after the final analysis of the trial, when funding will be sought to identify molecular and cellular correlates of therapeutic response in the event of a statistically significant benefit for Tocovid SupraBio/ PTX combination.

Inclusion Criteria - Age over 18 years. Past history of a malignant pelvic neoplasm (T1-4 N0-2 M0) of the rectum, prostate, testis, bladder, uterine cervix, uterus, vagina, vulva, anal canal or ovary. A minimum 12 months follow-up post-radiotherapy (24 months for patients with past history of stage T4 and/or N2 disease). A maximum 7 years post-radiotherapy No evidence of cancer recurrence. Gastrointestinal symptoms attributable to prior radiotherapy: grade 2 or higher in any CTCAE Version 4 category, or grade 1 with difficult intermittent symptoms. Symptoms are not relieved by appropriate life-style advice and medication over a 3-month period. Physical and psychological fitness for Tocovid SupraBio+PTX therapy. Written informed consent and availability for follow up. Willingness to keep to a specified level of dietary fat intake during the study. Exclusion Criteria - Surgery for rectal cancer. Contra-indication or other inability to undergo magnetic resonance imaging, if required to rule out malignancy. Dietary supplementation containing alpha-tocopherol above a daily dose of 30mg at any time during the last three months. Medication with pentoxifylline at any time since radiotherapy. Pregnancy or breast feeding. Ischaemic heart disease, uncontrolled hypertension, hypotension, acute myocardial infarction, cerebral haemorrhage, retinal haemorrhage, renal failure, liver failure and medication with insulin, ketorolac or vitamin K. Allergy to soya. Known hypersensitivity to the active constituent, pentoxifylline other methyl xanthines or any of the excipients', as per SmPC for pentoxifylline.

Andreyev HJN, Matthews J, Adams C, Gothard L, Lucy C, Tovey H, Boyle S, Anbalagan S, Musallam A, Yarnold J, Abraham D, Bliss J, Abdi BA, Taylor A, Hauer-Jensen M. Randomised single centre double-blind placebo controlled phase II trial of Tocovid SupraBio in combination with pentoxifylline in patients suffering long-term gastrointestinal adverse effects of radiotherapy for pelvic cancer: The PPALM study. Radiother Oncol. 2022 Mar;168:130-137. doi: 10.1016/j.radonc.2022.01.024. Epub 2022 Jan 29.