A rapamycin derivative, CCI-779 or temsirolimus, has been developed by Wyeth-Ayerst Labs, the pharmaceutical division of American Home Products Corp. It inhibits the mTOR pathway.
In 2004, one trial pertained to GIST:
CCI-779 in Treating Patients With Soft Tissue Sarcoma or Gastrointestinal Stromal Tumor
However, the above trial is no longer recruiting.
Please see a newer trial using a combination of temsirolimus plus sorafenib.