ASCO reports Sutent as important drug for pediatric GIST

By Norman Scherzer

For the first time at the American Society of Clinical Oncology (ASCO) conference, a poster was presented with a report about pediatric GIST patients responding to a drug. Although quite preliminary and limited to three patients, the report noted that, after 5 cycles of Sutent (sunitinib malate), there was important anti-tumor activity in pediatric GIST patients with Gleevec (imatinib) resistance therapy. All GIST lesions were reported to have stabilized or decreased in size with complete regression of two lung nodules in one patient.

The data presented is consistent with internal reports that the Life Raft Group has been receiving from pediatric GIST patients, some of whom may have been included in the poster presentation. Pediatric GIST patients generally seem to have no detectable KIT or PDGFR-a mutations (“wild type GIST”). In earlier studies with adult GIST patients who had a similar genotype (i.e., wild type GIST), significant clinical benefit was reported for Gleevec resistant patients treated with Sutent.

The authors of the poster conclude that an expanded phase l/ll trial of Sutent in pediatric GIST is warranted.

Note: While at ASCO we also received an update about a pending clinical trial for treating pediatric GIST patients with Gleevec. This trial has been in the discussion and planning stage for about two years. It does not currently have a component for testing pediatric GIST patients with Sutent. Although there is insufficient data about the efficacy of either drug, we have not observed responses by pediatric GIST patients to Gleevec similar to those reported about for Sutent. Although we recognize that the Life Raft Group database of about 25 pediatric GIST patients is hardly a substitute for any randomized clinical trial, we submit that any such trial that does not include a Sutent arm does not take advantage of our most current information that strongly suggests that wild-type GIST patients (both adult and pediatric) do not seem to respond to Gleevec and do seem to respond to Sutent.