Tri-specific NK cell Engagers (TriKEs) and Tetra-specific NK cell Engagers (TetraKEs)
The generation of Chimeric Antigen Receptor, or CAR, expressing T cells from monoclonal antibodies has represented an important step forward in cancer therapy. These therapies involve the genetic engineering of T cells to express either CARs, or T cell receptors, or TCRs, and are designed such that the modified T cells can recognize and destroy cancer cells. While a great deal of interest has recently been placed upon Chimeric Antigen Receptor T, or CAR-T, therapy, it has certain limitations for broad potential applicability because it can require an individual approach that is expensive, time consuming, and maybe difficult to apply on a large scale. We believe there is an unmet need for targeted off-the-shelf therapies that can be used on a stand-alone basis, augment the current monoclonal antibody therapeutics and be used in conjunction with more traditional cancer therapy.
To accomplish this goal, we have generated a pipeline of clinical and non-clinical product candidates consisting of tri-specific killer engagers, or TriKEs, and tetra-specific killer engagers, or TetraKEs, designed to target natural killer, or NK, cells and tumor cells forming] an immune synapse between the NK cell and the tumor cell thereby inducing NK cell activation at that site. NK cells mediate ADCC through the highly potent CD16 activating receptor.
We believe our product candidates have the potential to overcome some of the limitations of CAR-T therapy and other antibody therapies. Unlike full-length tri-specific antibodies, TriKEs and TetraKEs are small single-chain fusion proteins that bind the CD16 receptor of NK cells directly producing a more potent and lasting response as demonstrated by preclinical studies. An additional benefit that they may have is an attractive biodistribution as a consequence of their smaller size which is expected to be important in the treatment of solid tumors. In addition to these advantages, TriKEs and TetraKEs are designed to be non-immunogenic, have quick clearance properties and can be engineered quickly to target a variety of tumor antigens. We believe these attributes make them an ideal pharmaceutical platform for potentiated NK cell-based immunotherapies.
Therapeutic Antibody-Drug Conjugates Drug Development Program
ADCs are a new class of highly potent biopharmaceutical drugs designed as a targeted therapy for the treatment of cancer. By combining the unique targeting capabilities of monoclonal antibodies with the cancer-killing ability of cytotoxic drugs, ADCs allow sensitive discrimination between healthy and diseased tissue. We believe our bi-specific, ligand-directed single-chain fusion protein represents the next generation of ADCs.
Central Nervous System
Our CNS portfolio consists of innovative reformulations and/or repurposing of existing therapies that and are covered by issued or filed composition of matter patents. We believe our CNS product candidates address numerous unmet medical needs that can lead to improved efficacy while addressing tolerability and safety issues that tend to limit the usefulness of the original approved drug. Our CNS drug candidates address disease states such as chronic neuropathic pain (trigeminal neuralgia), myasthenia gravis and vestibular disorders.
We expect to complete proof-of-concept clinical trials for both GTP-004, for the treatment of the muscle weakness associated with myasthenia gravis, and GTP-011, a 72-hour patch for which a patent application has been filed by GTP for the prevention of motion sickness, in the first half of 2018. We anticipate that the new drug application, or NDA, will be a 505(b)2 NDA for each of these programs. We expect to complete a bioequivalence study for PainBrake for trigeminal neuralgia, in Q4 2018 and to file its NDA for this Orphan Drug indication in the first half of 2019.
We expect to take advantage of our CNS portfolio through self-commercialization, entering into partnering transactions with larger pharmaceutical companies and/or other structured transactions.