This is a two-center pharmacological open-label non-randomized proof of principle study consisting of two parts: a phase I study evaluating the RP2D of galunisertib in combination with capecitabine; and a phase II study investigating the anti-tumor activity and safety of galunisertib in combination with capecitabine in advanced colorectal cancer (CRC) with peritoneal metastases (PM).~In phase II of the study a Simon two-stage design will be used. 15 patients will be treated with the galunisertib/capecitabine combination. If at least 2 out of 15 patients respond, an additional cohort of 10 patients will be included to a total of 25 patients. With 6 or more responses, the treatment will be declared to be of sufficient activity and with 5 or less it will be declared of insufficient activity.~The galunisertib dose will be 150 mg twice daily (BID) for the first 14 days of every 4-week cycle, which is the maximum tolerated dose when given as single agent (except of day 1 of cycle 1: single dose of galunisertib 150 mg for PK analysis, from day 2: 150 mg BID).~Capecitabine will be dosed during every 14-day on time of galunisertib at 1000 mg/m2 BID, which is the labelled dose as monotherapy and will in case of toxicities be reduced according to standard care.~Clinical assessments will be performed routinely to monitor safety. Anti-tumor activity will be measured by CT scan according to RECIST 1.1 criteria. Tumor biopsies will be obtained for exploratory objectives.
This is a two-center open-label non-randomized proof of principle study consisting of a dose-finding part (phase I) and phase II study with Simon two-stage design investigating the anti-tumor activity of the combination of capecitabine and galunisertib in patients with colorectal cancer with peritoneal metastases.