In recent times there has been a renewed interest in natural products as a source for new drugs. Celtic Biotech believes that this technology, based on certain animal venom toxins that interact with cellular membranes, comes at a timely moment when the cancer research industry is most open to look at new sources of therapeutic compounds. There is an empirical demand for new oncology products.
Our candidate products are;
Crotoxin (CB-24) is a heterodimeric cytotoxic phospholipase complex protein isolated from the venom of a South American rattlesnake that has an inbuilt targeting mechanism and selectivity for tumour cells and in vitro, the anti-tumour activity of Crotoxin is extremely rapid. For example, in the human mammary tumour cell line, the exposure to Crotoxin killed 90% of cancer cells in 6 hours while 60% of exposed normal human keratinocytes (skin cells) cultures were healthy after four days incubation. The clinical anti-tumour activity of Crotoxin has also shown highly impressive results against a variety of cancers in both human and animal subjects.
Cardiotoxin (CB-6), like Crotoxin, is a therapeutic protein derived from cobra venom. At subtoxic concentrations, Cardiotoxin enhanced vinblastine cytotoxicity in one particular ovarian cancer cell line 6-fold. Cardiotoxin also significantly reduced cell viability in human T-cell leukaemia line and acute myeloid leukaemia (AML) lines. It caused a decrease in cell viability of about 50% in the AML lines. Clinically Cardiotoxin’s main impact is that it can improve the activity of other anticancer/ chemotherapeutic agents. Studies were conducted with Cardiotoxin to assess its effects in animal models of chronic kidney disease. In this application, Cardiotoxin was being employed as a therapeutic, and it was found to ameliorate symptoms of the disease in the treated animals for which there are currently no significant treatment options for humans.
CTC310 is a combination of CB-24 and CB-6. This combination product has an enlarged "therapeutic window" (the difference between the therapeutic and the unwanted toxic doses). Analysis of National Cancer Institute in vitro data shows that the addition of CD to CT in the CTC-310 product results in a potentiation of up to 60%. In general, the combination of these two agents results in a synergistic increase in in-vitro potency rather than a simple additive effect. The effect of CTC310 was examined in-vivo in mice models with implanted cancers and positive responses were observed using growth inhibition and life spans as endpoints. The Company will continue to conduct studies into this drug with a view to future Phase II clinical trials in specific cancers such as myelomas and leukaemia’s.
Crotalin (CB-CDV) was used clinically in the early 1900s to treat epilepsy with poor success. Recent laboratory data suggests that it may have activity against benign and malignant brain cancers. Crotalin is expected to be used against cancer that is resistant to Crotoxin and would have its first application in animal healthcare in the treatment of canine tumours.
The Company is investigating Crotamine (CB-5), another anti-tumour peptide from the Viperidae family, with exciting potential anti-cancer and gene therapy research conducted at the world-renowned Instituto Butantan, Brazil.
The Company expects that these peptide-based membrane interactive compounds could open a new category of molecular targeting therapies since they differ radically from standard chemotherapy or combination therapy, i.e. do not interfere with the cellular DNA structure or metabolism, and are not anti-metabolites or enzyme inhibitors. The U.S. National Cancer Institute evaluations of the pattern of anticancer activity found it to be unlike that of any known agent for which a mechanism of cell killing had been determined, making the use of Crotoxin a completely novel therapy for the treatment of cancer.
The Company also envisions that since its investigational drugs show qualities suggesting a unique mechanism of action, they may also be useful in the future in combination with conventional oncological approved therapies.