Apheresis prior to starting Keytruda?

[rsgdmd]

Will be starting Keytruda later this month and MO wants to do apheresis to collect T cells to freeze for possible CAR-T therapy in future, if Keytruda doesn't work well or issues with SEs. Makes sense, but wonder about taking T cells away perhaps less than a week before trying to boost their activity.

[Tall_Allen]

I think you are raising a good issue.

[tango65]

You should consult with a hematologist. Many oncologists are also hematologists.

Keytruda blocks a protein in the T cells call PD-1 making the T cells not to be fooled by the cancers cells expressing the PD-L 1 protein and recognizing the cancer cells as cells that should be destroyed.

Since PD-1 helps maintain the body's immune responses in check keeping the immune system for attacking normal tissues, most probable they will not want to make CAR T CELLS with cells having the PD-1 blocked.

If Keytruda fails and it is not adequate to make CAR T CELLS with the PD-1 blocked, you may have to wait several months after stopping Keytruda to collect the T cells since they may live several months.

[rsgdmd in reply to tango65]

They want to do the apheresis before starting Keytruda, which will prevent that issue. My concern is harvesting T cells a week before starting Keytruda.