An early study of the drug figitumumab has found that in some patients it can curb the growth of Ewing's sarcoma - a cancer which affects mainly teenage boys. The study was led by Dr Johann de Bono, from The Institute of Cancer Research and The Royal Marsden Hospital, and funded by Pfizer, who developed the drug.

The promising results, published online in The Lancet Oncology today, have led to the drug's progression to a Phase II trial in patients with Ewing's sarcoma, which has recently finished recruiting.

Ewing's sarcoma is a rare disease in which cancer cells are found in the bone or soft tissue, most often the pelvis, femur, humerus and ribs. It is more common in males than females, and most often develops between the ages of 10 to 20.

Previous studies have shown that a molecule called insulin-like growth-factor-1 receptor (IGF-1R) is involved in the growth and spread of Ewing's sarcoma and other sarcoma subtypes. Figitumumab is an antibody that blocks IGF-1R and so scientists investigated whether this drug could be used to treat Ewing's sarcoma and other sarcomas.

Between January 2006 and August 2008, a Phase I trial was carried out to assess whether the drug was safe for sarcoma patients. Figitumumab was given to 29 patients with advanced sarcomas who were responding poorly to conventional treatments, including 16 patients with Ewing's sarcoma. Six patients were aged 18 years or younger, and the median age was 30. The patients had already tried on average three cycles of chemotherapy, 21 had been given radiotherapy and 20 had already undergone surgery.

Side effects were mostly mild to moderate (grade one and two). More serious side effects that required treatment, back pain, vomiting and deep vein thrombosis (grade three), were each noted once in individual patients; a blood test showed one patient had high levels of liver enzymes; and one patient had high concentrations of uric acid (grade four).

Twenty eight patients were also able to be assessed to determine whether their cancer responded to the drug. Scans showed one Ewing's sarcoma patient was free of cancer after treatment, a second Ewing's sarcoma patient's tumour shrunk, and tumours stabilised for at least four months in a further six patients. Among non-Ewing's sarcoma patients, tumours also stabilised for around nine months in one patient with fibrosarcoma and a second patient with synovial sarcoma.

Dr de Bono says: "Our results show this drug can be safe for both children and adults with sarcoma. Although this trial was designed just to measure safety, for most patients we were also able to measure the drug's effect on their tumours. We found cancer shrank or stabilised for patients with several sarcoma subtypes, including about half of the patients with Ewing's sarcoma."

"Larger Phase II trials of this drug have just finished recruiting at multiple centres around the world, including a trial in Ewing's sarcoma patients involving our colleagues at the ICR and the Royal Marsden. We look forward to assessing these results."

The study was a collaboration between the ICR and The Royal Marsden in the UK and the Mayo Clinic, the University of Michigan Cancer Centre and Pfizer Global Research and Development in the US.

Source: The Institute of Cancer Research