Patients receiving immunotoxin cancer therapy are less likely to experience the deleterious side-effects associated with non-discriminate therapies such as chemotherapy or radiation therapy. Unfortunately, the continued administration of immunotoxins often leads to a reduced patient response due to the formation of neutralizing antibodies against immunogenic epitopes contained within Pseudomonas exotoxin A (PE).
Mesothelin (MSLN) is an excellent target for antibody-based therapies of cancer because of its high expression in many malignancies but lack of expression on essential normal tissues. Unfortunately, a large fragment of MSLN is shed from cancer cells, causing the currently available anti-MSLN antibodies (and immunoconjugates thereof) which bind to the shed portion of MSLN to quickly lose their therapeutic effectiveness over time. Indeed, the shed portion of MSLN can act as a decoy for these antibodies, further limiting them from reaching and destroying tumor cells.
Human mesothelin is overexpressed by various cancers such as synovial sarcoma, mesothelioma, and ovarian, lung, esophageal, and gastric cancers. This selective expression on certain cancers suggests that mesothelin is an excellent target for anticancer therapeutics. However, a large fragment (“the shed portion”) of mesothelin is constantly shed from cells, and all current anti-mesothelin antibodies bind to the shed portion.
Recombinant Immunotoxins (RITs) are chimeric molecules composed of an antigen binding domain and toxin. The antigen binding domain component targets the cancer cell and delivers the toxin component to the cell. However, the efficacy of RITs is limited by their short half-life once they are in the patient. To address this problem, investigators at the National Cancer Institute (NCI) increased the half-life of RITs using polyethylene glycol (PEG).
Targeted toxins (e.g., immunotoxins) are therapeutics that have at least two important components: (1) a toxin domain that is capable of killing cells and (2) a targeting domain that is capable of selectively localizing the toxic domain to only those cells which should be killed. By selecting a targeting domain that binds only to certain diseased cells (e.g., a cell which only expresses a cell surface receptor when in a diseased state), targeted toxins can kill the diseased cells while allowing healthy, essential cells to survive.
Recombinant immunotoxins (RITs) constitute a promising solution to hematologic cancers (e.g., Multiple Myeloma [MM]). RITs are chimeric proteins composed of a targeting domain fused to a bacterial toxin. Upon binding to a cancer cell displaying the target antigen, RITs are internalized, metabolized and the released toxin kills the cell. While highly active and effective, current RITs have short half-lives, requiring them to be used in high concentrations for treatment. At such high concentrations, RITs may show nonspecific activity and kill healthy cells.
Researchers at the National Eye Institute (NEI) have discovered an invention describing a composition and method(s) of using such composition for preserving viability of cells, tissues, or organs at a low temperature (around 4ºC). Current cold storage solutions or methods for cells, tissues, and organs are suboptimal due to irreversible damage to cold-sensitive tissue or organ transplants that need a longer term of storage for facilitating clinical practices.
Human cancers contain genetic mutations that are unique to each patient. Some of the mutated peptides are immunogenic, can be recognized by T cells, and therefore, may serve as therapeutic targets.
Triple negative (progesterone receptor (PR)-, estrogen receptor (ER)-, human epidermal growth receptor 2 (HER2)-) breast cancer (TNBC) is an aggressive subtype that affects 15-20% of the 1.7 million cases of breast cancer occurring annually. Currently, standard treatments of TNBC include cytotoxic chemotherapies, surgery, and radiation. However, TNBC readily becomes resistant to chemotherapy, and those with TNBC are more likely to have a recurrence or die within five years compared to those with other breast cancer types.
Diverse human cancers like colorectal, pancreatic, ovarian, melanoma, and pre-cancers express NADPH oxidases (NOX) at high levels. Reactive oxygen species (ROS) produced from metabolic reactions catalyzed by NOX in tumors are essential to the tumor’s growth. Though drugs that inhibit ROS production by NOX could be effective against a variety of human cancers, these types of drugs are not widely available.