Antibody-Directed Immuno-Conjugates (ADCs)

ADCs are a relatively new class of anti-tumor agents that combines tumor-selective monoclonal antibodies, or fragments thereof, linked to protein molecules for selectively delivering potent toxins to tumor cells. Unlike chemotherapy, ADCs are designed to identify and primarily kill only the cancer cells and spare healthy cells by combining the unique targeting capabilities of monoclonal antibodies with the cancer-killing ability of cytotoxic drugs.

Conventional chemotherapy aims to eliminate fast-growing tumor cells. It can, however, also harm healthy, growing cells, which causes adverse side effects. In contrast, ADCs can increase the efficacy of therapy and reduce systemic toxicity, often seen with small-molecule drugs. The focused delivery of the cytotoxic agent to tumor cells is designed to maximize the anti-tumor effect and cause quick cell death while minimizing damage to surrounding healthy tissue.

Clinical applications are rapidly accelerating thanks to improved technology and more refined targeting capabilities.

Advancing a New Series of ADCs

Istari Oncology’s second technology platform consists of a series of ADCs for a variety of oncology targets. These select, highly specific, monoclonal antibodies are presently conjugated with PE-38 toxin to maximize the killing effect.

We believe our platform overcomes some of the challenges associated with other ADCs because it is based on genetic linkage, which provides more stability than chemical linkers, making it is easier to manufacture. The FDA granted our ADC conjugate, D2C7-IT, Orphan Drug designation in 2016.

Beyond the various PE-38 toxins, our technology could be linked with other therapeutic agents for different targets. Toxins used in construction of immunotoxins are typically derived from bacteria, fungi, and plants. These agents and linkers potentially provide another platform for additional pipeline therapeutics. Possible tumor targets include solid, nonlymphoid tumors.