HQK-1004, a SCFA compound, acts by inducing the expression of a gene for a viral enzyme, thymidine kinase (TK). This enzyme is the target of several common anti-viral drugs, but the gene is silenced in a number of viral-related diseases making them resistant to standard anti-viral therapeutics. Inducing the expression of the silenced gene enables the use of these anti-viral drugs, such as ganciclovir, to destroy virally-infected cells, while leaving healthy cells unaffected by the therapy.

We are currently focusing our efforts on developing HQK-1004 for treating hematologic malignancies due to Epstein-Barr virus (EBV), which does not express the viral TK gene. EBV is associated with many kinds of cancers of the immune system, known as lymphoid malignancies. Without TK expression, these cancers cannot be treated with anti-viral drugs and also respond poorly to chemotherapy with short patient survival. A pilot clinical trial carried out by our founders demonstrated that 10 out of 15 patients (67%) with relapsed or refractory EBV lymphoid malignancies demonstrated objective tumor responses to this therapy. The treatment was well-tolerated without the myelosuppressive effects observed with cancer chemotherapy drugs.

This treatment appeared to be effective, but only a 3 week course of HQK-1004 therapy was tested in the pilot clinical trial. Laboratory studies in addition to observations from the pilot clinical study suggested that a briefer therapeutic regimen could be equally efficacious. Consequently, we and our collaborators are now carrying out clinical studies to test a shorter course of therapy with the goal of making it more adaptable for broader use. A trial testing this regimen has recently begun at a single clinical site. HemaQuest is also planning to start a multi-center clinical study in early 2010 to confirm and extend the findings from this study. If these studies confirm the clinical efficacy demonstrated in the pilot study, we plan to move forward with a pivotal trial in 2011.

This same proprietary therapy using HQK-1004 also has the potential to treat other EBV-related malignancies, including stomach cancer and nasopharyngeal carcinoma, two of the most common cancers in Asia which are increasing in prevalence in the United States. This therapeutic approach could also prove useful to treat other viral infections, such as cytomegalovirus, herpes zoster and HIV, all characterized by silenced genes that if reexpressed can be treated with standard anti-viral drugs.