Bioengineers may have found a way to use tamoxifen activated with blue light to control precisely which tissues and body areas CAR T cells attack, reducing toxicities in other parts of the body. They reported their work in ACS Synthetic Biology.
The researchers engineered CAR T cells that are only activated once they are treated with tamoxifen and then exposed to short pulses of low-intensity blue light. Using one trigger without the other does not activate the treatment, so any CAR T cells not exposed to blue light remain harmless to healthy organs and tissues. This would spare life-threatening toxicities to the heart, lungs, and liver, which are current drawbacks to existing CAR T-cell therapy.
So far the researchers have tested the treatment in live cell cultures and plan to move to testing mouse models. If it successfully translates to practice one day, they noted that it would be used for cancers of the skin, head, and neck because the blue light does not penetrate deeper into the body. They are also looking to collaborate with clinicians to do in vivo testing with melanoma.