A Phase III clinical trial conducted by the Children’s Oncology Group has shown a drug combination to be highly effective in children with standard and high-risk acute promyelocytic leukaemia, also known as APL. The trial was funded by the National Cancer Institute, part of the NIH.
The results of the trial were published in JAMA Oncology on 11 November, which studied the treatment of APL with the combination of all-trans-retinoic acid – a metabolite of vitamin A – and arsenic trioxide. Nearly all patients in the trial survived for two years without experiencing a relapse, and none of the children with standard-risk APL required conventional chemotherapy. Those with high-risk APL received only four doses of the chemotherapy drug idarubicin (Idamycin PFS).
In the trial, 154 children between the ages of 1 and 22 who were newly diagnosed with standard- or high-risk APL were given oral all-trans retinoic acid, alongside intravenous arsenic trioxide, for a minimum of 28 days. Children with standard- and high-risk APL had two-year overall survival rates of 99% and 100% respectively, and event-free survival rates of 98% and 96% respectively. Fewer than 10% of the children experienced severe side effects, and these occurred only in the initial phase of treatment.
Side effects for the treatment included increased blood sugar, liver irritation, and bleeding. Some of the patients with high-risk APL developed mouth sores from the idarubicin treatment they were given.
APL is an acute leukaemia, meaning it develops quickly and requires immediate treatment. Only 160 in the UK are diagnosed with the condition each year. The average age of diagnosis in children is 8 to 10 years, and symptoms include excessive bleeding, easy bruising, low red blood cell count, fever and fatigue. Previous standard treatment for APL in children involved anthracyclines, which can damage the heart.
