Interview with John Docherty, President, Helix BioPharma

The Canadian biopharmaceutical company Helix BioPharma is focused on the development and commercialization of innovative cancer therapeutics, specifically protein therapeutics for cancer. Founded in 1995 through a series of mergers, Helix BioPharma is publicly listed on the Toronto Stock Exchange as HBP. Based on its proprietary core technologies, Helix’s two key initiatives are Topical Interferon Alpha-2b, a treatment for the prevention of the development of cervical cancer that is caused by the numerous strains of HPV; and L-DOS47, an enzyme that specifically targets the environment surrounding lung adenocarcinoma cells to create an anticancer effect.

Helix’s Biphasix™ technology is specifically designed for moving large molecules across the skin/mucosal tissue. The Topical Interferon Alpha-2b cream is designed to deliver interferon alpha-2b molecules to the basal epidermal layer and help prevent HPV infections from potentially leading to cervical cancer.

JD: HPV affects 20 million people in the U.S. alone. Once a woman contracts HPV she can develop potentially pre-cancerous lesions of the cervix that may or may not progress to cervical cancer. These lesions are basically abnormal cervical tissue that are dysplastic in nature and, if not resolved, can progress to cervical cancer. The lesions themselves are occurring at a rate of one million abnormal pap smears per year in the U.S. with similar numbers in Europe. Currently, there is no pharmaceutical therapy for these patients and when you look at the numbers involved, we think there is a significant unmet medical need here.

OBR: Right now, what happens when an abnormal pap smear occurs?
JD: There’s a mandate that doctors have to follow in the U.S. and Canada before prescribing a treatment. The only currently available treatments have to be administered in a hospital-type setting because they are surgical or interventional in nature. In mild cases, doctors can use laser surgery or use cryotherapy (freezing) to remove the lesions. In more advanced cases, a LEEP excision is usually performed or a conization which is the removal of abnormal tissue from the cervix. However, in all of these procedures, a battery of side effects can occur that doctors and patients would like to avoid. Side effects can be abnormal discharges, infertility or even pre-mature labor. In lieu of these types of procedures, we hope to provide doctors and patients with a pharmaceutical treatment option.

OBR: Have you completed any clinical studies with Topical Interferon Alpha-2b?
JD: In 2007, we completed a small Phase 2 study in women with HPV-induced low grade squamous intra-epithelial lesions (LSIL) and recorded positive findings. This was a four-center study that included 41 women: 20 in the treatment group and 21 in the control group. The women were treated for 6 weeks with a follow-up at 12 weeks. We showed resolution—meaning that pap smears went from abnormal to normal with no evidence of dysplasia, even upon colposcopy, in just under half of the patients that received treatment versus those patients that received no treatment. It was aggressive therapy and our docs were pretty amazed with the results. This has set the stage for the next phase of trials. That’s the plan. We’re moving to randomized, double-blind, placebo-controlled trials.

OBR: What is your L-DOS47 initiative?
JD: We have developed a product to modify the microenvironment associated with cancer cells. Cancer cells in any given solid tumor exhibit certain traits, including an acidic extra cellular compartment. This compartment has an abnormally low pH level as a result of the metabolic function of cancer cells. Healthy cells, in comparison, are more alkaline in nature. The difference in acidity is thought to play a role in a cancer cell’s ability to invade and metastasize. So we decided to develop a therapeutic that will change that environment from acidic to alkaline.

OBR: Do you have a core technology for that as well?
JD: Yes. DOS47 is the general substance that we want to get to the site of the cancer cell in order to reverse the acidity. To achieve this, we’ve conjugated DOS47 with an antibody fragment specifically designed to target the lungs, and we call it L-DOS47. L-DOS47 is an i.v. product that has incredible specificity for NSCLC cells, and doesn’t bind substantially to healthy tissues or any other cancers for that matter. Once you get DOS47 to the site of the tumor, its activity is extra cellular in action.

Many of today’s compounds have to penetrate the cancer cells in order to function. We’re interested in parking L-DOS47 on the external surface of the cancer cell, where the antigen binding site is for the L-antibody, and then allowing it to cause a biochemical reaction that will modulate the acidity to become alkaline. In addition, L-DOS47 is believed to cause the production of ammonia molecules which readily diffuse into cancer cells and have a cytotoxic effect.

In theory, we think the move from an acidic to alkaline microenvironment has a combination of effects that debilitate the ability of the cancer cell to metastasize and invade. In addition, the cancer cell can’t be supported in an alkaline environment. L-DOS47 is still in the pre-clinical stage, but our goal is to file an IND and move to Phase 1 trials this year.

OBR: Are you looking to partner with your technology?
JD: We’ve already partnered with Schering-Plough to develop Topical Interferon Alpha-2b. With L-DOS47, because of its behavior in reversing acidity and moving to alkalinity, we think there is very strong commercial partnering potential for adjunct application where it would be used with some of the leading therapeutics for NSCLC. We’ll look to evaluate those in time, for now we are coming out of the Canadian woodwork so to speak.

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