The goal of this project is to establish a new platform technology that addresses fundamental limitations of
current approaches against tumors driven by intracellular oncoproteins. Many oncogenes encode activated
versions of intracellular proteins. Although biologics are revolutionizing cancer therapy, they do not readily
enter cells and thus are ineffective against intracellular targets. Fragments of intracellular proteins are
presented by MHC molecules on cell surface, but it is challenging to recognize differences between healthy
proteins and their oncogenic counterparts that are often minute. Many covalent inhibitors have been developed
against intracellular oncoproteins, but most of them, like other targeted therapies, evoke resistance and fail to
achieve cancer cures. By contrast, “immune therapies” (e.g., immune checkpoint inhibitors, CAR-T cells) can
be curative, but most intracellular oncogene-driven tumors fail to respond to these agents.
We propose a potentially transformative innovation that unites targeted therapy using covalent inhibitors
with immune therapy using biologics. We will develop “HapImmune” antibodies that selectively recognize
fragments of an oncoprotein covalently linked to an inhibitor and presented by MHC Class I on the surface of
cancer cells. The conjugated inhibitor serves as a hapten that increases the immunogenicity of the oncoprotein
fragments. Co-administration of drug and antibody will initiate killing of cancer cells by engaging immune
attack, antigen spreading and ultimately durable anti-tumor immunity.
Compelling preliminary data demonstrate that HapImmune antibodies can be generated against several
drug-peptide conjugates. Our multi-disciplinary team with complementary expertise in cancer biology, drug
discovery, and antibody engineering is well positioned to further develop and explore the applicability of the
HapImmune concept for improving targeted therapy. We will execute the following two Aims: (1) We will
develop antibodies that bind a covalent drug, AMG510 conjugated with a KRASG12C peptide presented on an
MHC. Although AMG510 is expected to revolutionize therapy against cancers driven by KRASG12C, its efficacy
is short-lived. We will examine the efficacy of such antibodies in selective killing in vitro and in vivo of cancer
cells that have been pretreated with AMG510. These experiments will critically evaluate the impact of the
HapImmune approach using a major current target in cancer drug discovery. (2) We will assess the broader
applicability of the HapImmune approach using distinct target-drug pairs, using covalent inhibitors of EGFR
and BTK. We will develop antibodies to these conjugates presented on appropriate MHC molecules and test
their efficacy in cell-based assays. These experiments should provide a rigorous test of the general
applicability of the HapImmune approach and our ability to develop HapImmune antibodies.
If successful, this project will establish a facile pipeline to produce potentially transformative therapeutics
that can be rapidly translated into clinic.