As president and CEO of closely-held Soricimed Biopharma, Paul Gunn parlayed a 20-year career as a financial executive into funding the startup of Soricimed along with a tech transfer in 2005 facilitated by Mount Allison University in Sackville, New Brunswick, Canada. Admittedly, he was new to biotech and drug development in those days, but he moved into Soricimed as CFO in 2007 and became CEO a few years later. Today, the company is gaining an international following with its anti-cancer drug candidate, SOR-C13, and successful early human studies in solid cancer types. The company presented four posters at the American Association of Cancer Research in New Orleans last week about its preclinical and clinical research and supporting data. In this interview with BioTuesdays.com, Mr. Gunn discusses the early success of SOR-C13 and the drug’s future potential.
Let’s begin with a brief history of your drug candidate.
In 2000, Professor Jack Stewart’s research lab at Mount Allison learned of the paralytic nature of the saliva of the northern short-tailed shrew. After finding that no one had identified the paralytic principle, they began a research program to identify the compound produced in this venomous mammalian species. Within five years, Jack’s discovery of a proprietary bi-functional paralytic peptide, soricidin, with ion channel modulating characteristics soon became our C-series peptide platform.
Can you review the significant finding in your top-line Phase 1 results?
We were very pleased with the results because there were no serious drug-related adverse events and we demonstrated safety and tolerability of SOR-C13 in patients with 10 different solid tumor types. In addition, SOR-C13 demonstrated potential activity, with 55% of the 22 evaluable subjects achieving stable disease as defined by the clinical protocol while on treatment. The patients in the study were very sick, with stage 4, metastasized cancers who had failed all previous anti-cancer treatments and they had elevated levels of the calcium ion channel, TRPV6. However, we had one patient still on treatment and in stable disease after more than one year. And one pancreatic cancer patient showed tumor size reduction of 27% after four treatment cycles of 21 days each, with correlated reductions in a validated pancreatic cancer biomarker.
What’s the significance of targeting TRPV6?
A common factor in many solid tumor cancers is the presence of dysfunctional signaling triggered by too much calcium entry into cancer cells and the overproduction of a calcium ion channel that is not present, or present at low levels, in healthy tissues. The calcium channel that has come to light as a major player is TRPV6 (Transient Receptor Potential, Vanilloid family, number 6). Many solid tumors produce very large amounts of this channel and the flood of calcium into the cell appears to facilitate cell growth, division and metastases. Our C-series peptides, which have been developed from soricidin, selectively and powerfully stop the TRPV6 channels from working and reset the cell toward normal calcium content. While the involvement of the TRPV6 channel in tumor growth and metastasis has been recognized for about 15 years, our C-series peptides are the only known inhibitors of this channel in clinical development. In addition, the very low toxicity profile of our C-series peptides and lack of side effects is a powerful incentive for us to develop this class of compounds. SOR-C13 is the first drug candidate targeting TRPV6 to have entered clinical development anywhere in the world.
What interest have you had following the positive Phase 1 results?
We are aggressively looking at a partnering opportunity and are talking to a number of global and regional pharmaceutical companies. We would like to go into Phase 2 development with a partner, which is our goal, but recognize that we have to continue development of the drug if the right deal doesn’t come along.
What’s next in your clinical development plans?
We’re putting together a group of key opinion leaders to advise us on the best plan to move forward in terms of which type of cancer to target and the best patient population, for example. Those discussions will determine whether we pursue a Phase 1/2 or Phase 2 clinical trial.
But you have already have FDA orphan drug designation in ovarian cancer.
Ovarian cancer is one possibility going forward because we have had preclinical and clinical success. However, we also had success in the Phase 1 with pancreatic cancer, which is a significantly underserved market.
Can you discuss any new preclinical work?
One of our university colleagues has found anti-myeloma and anti-osteoclast activity of human TRPV6 antagonist peptides, SOR-C13 and SOR-C27. Taken together, these findings suggest a novel therapeutic approach for multiple myeloma involving TRPV6 inhibition to target both myeloma cells and the destruction of bone material by osteoclasts.