Bayer initiates a randomized Phase III trial of Regorafenib in GIST: On January 10, 2011 Bayer Healthcare in Berlin, Germany announced the initiation of a randomized phase III trial of Regorafenib (BAY 73-4506) for Gastrointestinal Stromal Tumor patients. This is a third-line trial for patients who have failed both Gleevec and Sutent.

Dr. George Demetri at Dana Farber Cancer Institute (DFCI) in Boston heads the steering committee for the trial and is quoted in the press announcement released by Bayer: “This Phase III trial was designed based upon strong signals of clinical activity seen in an academically designed, non-randomized, single-arm Phase II trial in GIST patients whose disease had exhausted all standard treatment options.”

However, the results of the Phase II Regorafenib trial in GIST have not yet been published.

The trial description indicates that subjects who have had “prior treatment with any other vascular endothelial growth factor receptor (VEGFR) inhibitor” are not allowed. Other VEGFR inhibitors used in GIST include Nexavar and less commonly, Votrient. Representatives from Bayer have verified that this requirement excludes GIST patients who have had prior Nexavar or Votrient treatment.

The Regorafenib Phase III trial is described as a randomized, double-blind comparison of two arms (or patient groups) assigned on a 2:1 basis. In a double-blind trial neither the patients nor the trial clinicians will know which group an individual patient is assigned to. Sixty-six percent of patients will be randomly assigned to the active group and will receive 160 mg Regorafenib. Thirty-three percent of patients will initially receive only an inactive placebo.

Patients entering the trial will then have a two out of three chance of receiving the active drug. Patients who experience progression during the trial will be subsequently “unblinded”. At unblinding both the patient and the clinician will find out if the patient is receiving Regorafenib or placebo. Patients who are unblinded and who are on placebo will be given the option to cross-over to the active group and receive Regorafenib. The trial protocol description indicates that patients in both groups will be treated in 28 day cycles with patients on treatment for 21 days then off treatment for seven days. Patients will be evaluated by CT or MRI every four weeks for the first three months or cycles. The RECIST criteria will be used to evaluate tumor response or progression. Scans will be reviewed by an independent central facility to confirm status.

Currently, Bayer provides only an email address for patients wishing to inquire about the trial: clinical-trialscontact@

The LRG will be working with Bayer to better understand how patients with limited email access can inquire about this trial. In the interim, the LRG will provide contact information in the site listings in our Clinical Trials Database as individual recruiting sites publish trial listings in their local registries. Click here for the LRG database listing for this trial.

The United States trial listing indicates that one site in Innsbruck, Austria is currently open. Plans are for 70 sites in 17 countries worldwide and 14 states in the United States. Estimated enrollment is 170 patients per the National Institutes of Health listing. We understand that 34 patients have already been accrued.

For additional details and clinical trial site listing that includes sites that are not yet recruiting, view the listing.