Initial results from the DeFi clinical trial show that the drug nirogacestat can improve outcomes for adults with progressing desmoid-type fibromatosis. The results are a promising step towards making the first approved treatment available for the disease.
The trial, which is taking place in 52 hospitals across the USA, Europe and the UK, found that nirogacestat reduces the risk of desmoid-type fibromatosis getting worse by 71%. Across the 142 trial participants, a high number responded to the drug overall. Nirogacestat was also found to be safe to be used as a treatment, and patients tolerated it well, with few side effects.
Desmoid-type fibromatosis, sometimes called desmoid tumours, are an especially rare subtype of soft tissue sarcoma, most commonly affecting women aged 20-44. It can occur anywhere in the body, but most commonly in the arms, legs and tummy. They are benign tumours, meaning they’re not cancerous. However, they can be very aggressive, and can have a real impact on patients’ quality of life. In rare cases, they can be life-threatening.
Phase 3 trials like DeFi aim to find out if a new treatment works better than the best currently available treatment. Because there are currently no drugs available to treat desmoid tumours, in this trial half of the participants were randomly given nirogacestat, and the other half were given a placebo drug. None of the trial participants or the researchers knew which drug they’d been given. Controls like this are important to correctly identify if the new treatment works.
Nirogacestat is a pill which stops the activity of a protein in the body which is known to contribute to the growth of desmoid tumours. It is also being explored as a treatment for other cancers like myeloma. Biopharmaceutical company SpringWorks Therapeutics plan to submit the drug for approval to the U.S. Food and Drug Administration later this year.
Dr Sorrel Bickley, Director of Research, Policy and Support at Sarcoma UK, said:
Although there’s a way to go before we might see nirogacestat as being used more widely in people with desmoid-type fibromatosis, these are very encouraging initial results. Desmoid-type fibromatosis can be incredibly debilitating so we welcome this exciting first step towards a new treatment.