Company develops nuclear countermeasure drug

US PHARMACEUTICAL COMPANY Chrysalis BioTherapeutics has received a US$3m grant from the National Institute of Allergy and Infectious Diseases (NIAID) to continue development of a nuclear countermeasure drug intended to prevent radiation sickness in the event of a nuclear accident or the intentional detonation of a nuclear device.

The Texas-based company says the drug can prevent radiation sickness and increase the survival chances of those exposed, by counteracting the effects of radiation on blood vessels and stem cells in bone marrow, skin, and the brain.

Chrysalis said that in preclinical studies conducted on mice, TP508 increased survival rates by 30–50% and delayed mortality for over six months when injected with a single dose up to 24 hours after lethal radiation exposure.

Darrell Carney, CEO of Chrysalis, said the agents can be prepared in simple, ready-to-use syringes and can be delivered rapidly, or dropped by helicopter after a nuclear event. He told The Chemical Engineer, “It is a first-line-of-defence drug that could be self-administered, or administered by non-medically trained personnel.”

The proprietary TP508 is a peptide-based drug that represents a portion of the thrombin molecule and is released into the body at sites of tissue injury to stimulate repair. It protects endothelial cells lining blood vessels and stimulates stem cells to replace radiation-damaged cells.

Laurie Sower, vice president of research at Chrysalis, said: “Because of its reparative effects, TP508, when injected systemically after radiation exposure, increases the body's capacity to fight infection, decreases bacterial septicaemia, and prevents death.”

This latest grant brings the total funding for the project to over US$6m, and will allow Chrysalis to complete a number of further studies required for US Food and Drug Administration (FDA) approval. Pending approval, Chrysalis hopes to stockpile the drug for emergency use.

Additional studies suggest the drug could also be used for wider clinical applications, such as preventing radiation therapy-induced cognitive decline in brain cancer patients. Carney said the drug would prevent radiation-induced damage to normal tissues while allowing radiation to kill tumour cells.