Immunovaccine (OTCQX:IMMVF; TSX:IMV) expects to report three clinical milestones for its killer T cell activation vaccine platform, DepoVax, in ovarian and HPV cancers in the next 12 months.
“Our DepoVax platform has the potential to revolutionize immunotherapy in multiple areas, such as oncology and infectious diseases,” CEO, Frederic Ors, says in an interview with BioTuesdays.com.
Last week, ImmunoVaccine reported positive top-line results from its Phase 1 trial evaluating the safety and immunogenicity of DPX-RSV, its DepoVax-based, small B cell epitope peptide vaccine candidate for respiratory syncytial virus (RSV).
Specifically, the study demonstrated that the vaccine had a positive safety profile and was well tolerated with no serious adverse events among all study participants. Antigen-specific immune responses were detected at least six months after the last vaccination in 93% of patients receiving DPX-RSV, in both low-dose and high-dose cohorts.
"We are thrilled with these results, as they go beyond our initial expectations,” Mr. Ors says. “We believe that our differentiated approach, along with this topline data, position DPX-RSV to address a significant unmet medical need in the RSV market."
Mr. Ors explains that DepoVax is a patented vaccine delivery formulation that acts like a depot, and provides controlled and prolonged exposure in terms of weeks, not hours, of antigens plus an adjuvant to the immune system.
“We have the ability to deliver multiple types of therapeutics to the site of cancer cells, including peptides, DNA and RNA, live vaccines and recombinant proteins,” he adds. “The result is a strong, specific and sustained immune response with the capability for single-dose effectiveness.”
Mr. Ors, who moved into the executive suite of Immunovaccine in the spring and engineered a corporate reset, with new management, a new board and a new business plan, says the company’s strategy is to work in partnerships with industry leaders, such as Incyte (NASDAQ:INCY), an unnamed large pharma company, Dana Farber Cancer Institute, UConn Health and Leidos.
The company’s lead oncology asset is DPX-Survivac, a water-free, lipid-based vaccine, which has been designed to target the survivin protein through an exclusive worldwide license from Merck KGaA of Germany.
Survivin is expressed in abnormally high levels in cancer cells and controls a number of critical cancer processes, such as apoptosis cell death, and cell division and metastasis, making it an important biomarker of cancer progression.
Data from an early Phase 1 trial was published last year in the peer-reviewed journal, Oncoimmunology, showing that DPX-Survivac in combination with a low dose of cyclophosphamide, an immune modulator, generated a high level of T cell activation in almost all study participants that was maintained for more than a year.
In a follow on study, one patient with measurable and stable disease achieved a 43% reduction in tumor size, demonstrating a durable clinical benefit associated with the DPX-Survivac therapy.
In the summer, Immunovaccine reported results of a 54-patient Phase 1/1b study of DPX-Survivac in combination with cyclophosphamide. The data showed that the vast majority of evaluable patients (47 of 54, or 87%) experienced acute T cell-mediated response to survivin and of those patients, sustainable T cell mediated activity was demonstrated longer term, with repeated DPX-Survivac administration (37 of 47 responsive patients, or 79%).
The study was not powered to assess progression-free survival (PFS), but some preliminary and positive insights into DPX-Survivac’s clinical prospects were clear, according to Echelon Wealth Partners analyst, Doug Loe, who initiated coverage of Immunovaccine in September.
Specifically, nine of 18 evaluable patients, those treated with at least three DPX-Survivac doses, experiencing PFS for at least two years, with three patients surviving for at least five years. “All about as positive as we would expect from an initial exploratory ovarian cancer study,” Mr. Loe wrote.
Mr. Ors says Immunovaccine and Incyte are currently enrolling patients in a new Phase 1b study of DPX-Survivac, in combination with Incyte’s checkpoint inhibitor, epacadostat, and low-dose cyclophosphamide in patients with recurrent ovarian cancer. Checkpoint inhibitors seek to overcome one of cancer's main defenses against an immune system attack.
“Our ultimate goal is to demonstrate that DPX-Survivac can prime the tumor, which with the help of checkpoint inhibitors, can be effective in reducing or eliminating the tumor and, in addition, expanding the market potential of our partner’s checkpoint inhibitors,” he adds.
Interim data from the first three-to-six patients in the study is due for release in the first quarter of 2017, with top-line results in the fourth quarter next year and final results in the fourth quarter of 2018.
Immunovaccine also plans to begin a Phase 1 trial in the first quarter of 2017 with an unnamed large pharma partner to test DPX-Survivac in recurrent ovarian cancer. In addition to safety and several secondary endpoints of survival, the goal is to use DPX-Survivac to double the current overall response rate of 11% of a commercial checkpoint inhibitor.
The study expects to enroll 32-to-35 patients, with 12-to-15 in a Phase 1 arm and 20 patients in a dose expansion cohort. Interim results from the study are due for release in the third quarter next year, with top-line results in the first quarter of 2018 and final results in the first quarter to 2019.
Immunovaccine also has partnered with the Dana-Farber Cancer Institute to study its DPX E7 vaccine in combination with cyclophosphamide in 50 patients with HPV cervical cancer. The Phase 1/2 study is scheduled to enroll its first patient in the fourth quarter this year, with interim data in the second half of 2017.
In its infectious disease program, Immunovaccine in July posted positive interim results for safety and immunogenicity of its DepoVax prophylactic respiratory syncytial virus (RSV) vaccine candidate, DPX-RSV, in a Phase 1 trial with healthy older adult volunteers.
RSV is a common virus that infects the lungs and breathing passages. While it usually leads to mild, cold-like symptoms, it can be severe in the elderly, infants and patients with compromised immune systems. There is no vaccine currently available to prevent RSV.
There were no serious adverse events in the Phase 1 study. In addition, DPX-RSV obtained antigen-specific antibody responses in 75% of subjects vaccinated with a low dose, and 100% of those vaccinated with a higher dose.
Mr. Ors says the company intends to seek licensing partners for its infectious disease platform on a “per application basis” in order to focus Immunovaccine on oncology.