Harnessing the patient’s own immune system to control metastatic disease has become a recent and exciting approach in cancer therapy, particularly inhibitors of programmed cell death, such as PD-1. The approval of two such agents, as well as an antibody that inhibits T lymphocyte-associated antigen 4 (CTLA4), has spurred interest in their combination with other therapies in order to achieve a synergism, whereby superior effects are achieved. We have begun to develop our own PD-1 antibody to evaluate its use in combination with our other anticancer agents, such as the antibody-drug conjugates sacituzumab govitecan and labetuzumab govitecan, in preclinical studies.
Another immunotherapy of current interest is utilizing chimeric antigen receptors (CARs) to direct T cells or natural killer cells. The engineering of chimeric antigen receptors on the surface of such cells combines the potent functions of the effector cells with the tumor-targeting properties of the antibodies. To-date, clinical results using CAR-redirected immunotherapy have appeared to be more successful in liquid (hematological) tumors than in solid cancers. Using our own genetic engineering technology, our scientists have begun work on a more universal approach to direct effector cells to a variety of cancer types by a next-generation targeting model. Preclinical studies are in progress while patents to protect the intellectual property are being prosecuted.
Finally, as described in the DOCK-AND-LOCK® platform technology section, we are developing an investigational T-cell redirected bispecific antibody that takes advantage of our TROP-2 antibody targeting, and has shown biological activity in our preclinical animal studies. We have now begun work to develop the constructs needed for translation into candidates for human clinical trials.