Pfizer’s cancer drug Sutent (sunitinib malate; SU11248) can delay the progression of a rare for of stomach cancer - gastrointestinal stromal tumours (GIST) – even in patients who have failed treatment with Novartis’ Glivec/Gleevec (imatinib mesylate), the last-line therapy for the disease.

Glivec revolutionised the treatment of GIST when it was approved for the this form of cancer in 2002 and has been a big earner for Novartis, with sales rising 31% to $1.58 billion dollars in the first nine months of this year in its two approved indications of GIST and leukaemia [[18/10/05g]]. But patients who do not respond to Glivec have run out of options. The new data, presented at the European Cancer Conference (ECCO) in Paris last Friday, suggest that Sutent can provide an additional line of defence.

Sutent, already submitted for approval in the treatment of renal cell carcinoma [[11/08/05b]], delayed the time to progression of GIST from 6.4 weeks in a control group of patients to 27.3 weeks. All those enrolled in the 312-patient study had already developed resistance to Glivec, something that typically occurs after two years treatment with Novartis’ drug. The trial has not yet been carried out for long enough to see whether Sutent improved survival in the patient group.

Preliminary results from the study were presented at the American Society of Clinical Oncology (ASCO) conference earlier this year [[17/05/05d]].

Sutent is an oral cancer therapy and one of the first in a new class of drugs that targets receptor tyrosine kinases to simultaneously starve tumours of blood and nutrients, and attack the cancer cells. In addition to renal cell carcinoma and GIST, it is being evaluated both alone and in combination with other medications as a treatment for other solid tumours, including breast, lung, prostate, and colorectal cancers.

- Also presented at ECCO were the results of a Phase II trial of Sutent in advanced breast cancer patients who had failed multiple earlier treatments with a taxane- or anthracycline-based chemotherapy regimen, or radiotherapy. Pfizer’s drug was able to provide partial responses or stabilise disease in about 16% of cases. The organisers of the study said that additional studies of Sutent in combination with other drugs and in patients who had not been so heavily exposed to other treatments.