A new drug has been shown in animals to accelerate the recovery of blood stem cells following chemotherapy and radiation.

Radiation and chemotherapy often damage the stem cells present in bone marrow that produce blood and immune cells, and recovery can take months. Researchers at the University of California, Los Angels (UCLA) have developed a new drug that could accelerate the process.

The drug targets the protein receptor protein tyrosine phosphatase-sigma (PTP-sigma). This protein is largely found in the nervous system and plays a key role in the regeneration of neurons. When this protein is inhibited, regeneration is accelerated after the neurons are injured.

The UCLA scientists found that PTP-sigma is also present on blood stem cells and functions similarly. When mice that had a PTP-sigma (PTPS) gene deficiency were subjected to radiation, damaged blood stem cells recovered more quickly.

Specific tyrosine phosphatases are often difficult to target with drugs, because the proteins in this family all have similar activation sites. The researchers evaluated 100 potential molecules and identified one candidate with the greatest potential. When damaged human blood stem cells in petri dishes were treated with DJ009, they recovered.

In mice treated with high doses of radiation or doses of chemotherapy drugs similar to those given to humans, the drug was shown to accelerate the recovery of blood stem cells, white blood cells and other components of the blood system. The scientists believe these results indicate the drug, if proven safe, has the potential to work in humans. They are currently optimizing the formulation of DJ009 and other candidates with the intent of advancing to clinical trials.