In the past decade, new innovations and well-funded research have heralded in the era of immunotherapy. The pace of change within the field has amazed Peter Hoang, the chief executive of a Jacksonville, Fl.-based company working to develop therapeutic vaccines for cancer.
“15 years ago, if you or I walked into a venture capitalist’s office, we probably would have gotten ourselves kicked out for suggesting that we wanted money for something like enlisting the immune system to fight cancer. But low and behold, 15 years later, it’s now a fairly transformative approach to cancer,” he told Drug Delivery Business News.
Hoping to be a part of that transformation, Hoang and his company, TapImmune (NSDQ:TPIV), are working on two clinical-stage vaccines that aim to take advantage of the best parts of immunotherapy, while eliminating the challenges experienced by other companies in the space.
He used immune checkpoint inhibitors, like Merck’s Keytruda and Bristol-Myers Squibb’s Opdivo, as an example – these products are effective in cancers like melanoma and lung cancer, where sun damage and smoking causes mutations that make the tumor easily detectable by the patient’s immune system.
“But when we move into cold tumors or particularly aggressive ones, then we’ve got more challenges. Because in many cases, the endogenous immune system simply isn’t seeing enough tumor, it’s not seeing enough antigen,” Hoang explained.
“If you want immunotherapies to be great and not just good, then what you have to do is find a way to enable the endogenous immune system to respond. How do you get endogenous T-cells that might otherwise not react, not proliferate, not expand and survive long enough to combat the tumor efffectively? Well that’s what cancer vaccines do,” he said. “Many of the most vexing problems in cancer immunotherapy today point to many of the things that our therapies do, which is one of the reasons why I’m so excited about it.”
TapImmune’s technology combines sets of peptide antigens that are designed to trigger both “killer” T-cell and “helper” T-cell immune responses. The antigens are derived from human immune responses that are recognized by more than 85% of the population, according to TapImmune, which could mean that the company’s vaccines will be effective in a broader patient population than traditional immunotherapies.
The company has four active Phase II trials, two for ovarian cancer and two for triple-negative breast cancer, as well as two Phase I breast cancer trials.
One of the trials that most excites TapImmune’s CEO is a Phase II trial evaluating its TPIV200 vaccine as a means to prevent cancer recurrence in women with ovarian cancer who have completed first-line surgery and chemotherapy.
“Most patients respond to first-line therapy. But once you get chemotherapy and surgery, you’re in a waiting period and you know the disease is going to relapse,” he said. “So, it’s a great time in the patients’ lives because it’s a reprieve from the disease, but it’s also a time when you’re very exposed. So the idea that they could take a cancer vaccine with very, very few caustic side effects and potentially extend the period that they will remain in remission is potentially transformative to their lives and the quality of life that they’ll have.”
The 120-patient Phase II trial is building off results from a Phase I trial, which showed “interestingly-long” progression-free survival in 10 ovarian cancer patients in their first remission, according to Hoang. While 10 patients is not a sufficient sample size from which to draw conclusions, Hoang sees the results as supporting evidence of the product’s potential.
“So if we see equally promising progression-free survival in this Phase II trial, with 120 patients we absolutely will reach the point of statistical significance. Then I believe that we have every opportunity to go back to the FDA and ask them to expand that 120-patient trial into a 300-400 patient trial and seek registration and approval if those results show a meaningful difference over the placebo,” he said.
TapImmune’s technology has also received some attention from the U.S. Dept. of Defense, which is funding two of its trials – one in patients with triple-negative breast cancer and one in ductal carcinoma in situ.
“The Mayo Clinic has been a critical partner of ours through the entire history of our therapeutic vaccine. Likewise, the DoD, by funding fully two of our clinical trials, has significantly multiplied our ability to be effective with the resources available to us. I think that going forward, we’re going to continue to leverage the force multiplier effect that hose collaborations have,” Hoang said.