Transfer factor immunotherapy in human cancer

Transfer factor immunotherapy is in an early stage of development, and there are necessarily a number of important variables in protocol. These include donor selection, activity assays for transfer factor, and the treatment regimen. Where tumor regression, clinical improvement and conversion of specific dermal reactivity occurred in the absence of other therapy, there seems little doubt that transfer factor had a significant effect. Where no improvement was observed, several possibilities deserve consideration: the donor may not have had effective antitumor immunity, the transfer factor may not have been active, the patient may have been immunologically refractive, or the tumor may have been directly or indirectly resistant to immune attack.