Seroprotective HAI antibody response persisted more than one year after vaccination
Company seeking partnership for further development and commercialization of NasoVAX
GAITHERSBURG, Md., March 19, 2019 (GLOBE NEWSWIRE) -- Altimmune, Inc. (ALT), a clinical-stage immunotherapeutics company, today announced additional positive data from a Phase 2 extension study of its NasoVAX intranasal influenza vaccine candidate. Data from this study demonstrated that 100% of the evaluated subjects remained seroprotected, and the seroconversion rate was unchanged more than one year after vaccination.
Subjects from the highest dose group of the study were invited to return as part of a study extension to evaluate the duration of immunity 1-year post-vaccination. Of 15 subjects invited, 8 returned an average of 13.5 months after vaccination. Antibody titers for all 8 subjects remained seroprotective, with a median hemagglutination inhibition (HAI) titer more than 3-times higher than generally accepted seroprotective levels. Coupled with previously demonstrated mucosal antibody and T-cell related correlates of immunoprotection, NasoVAX is well positioned to compete with other influenza vaccines currently under development.
“We are excited about the continued positive NasoVAX results and believe that if approved, NasoVAX has the potential to capture a significant portion of the global flu vaccine market,” said Vipin K. Garg, Ph.D., President and CEO of Altimmune. “Based on the continued positive data, we are seeking development and commercialization partnerships for our NasoVAX program. This will allow us to focus on our strategy of building a pipeline of multiple early to mid-stage assets. We are currently engaged in a rigorous acquisition review process focused on novel immunotherapeutic approaches for cancer, including immunostimulants and oncolytic viruses, and innovative product candidates for liver diseases. The proceeds from our recent successful financing efforts have put us in a strong position to execute our acquisition plans.”
NasoVAX, an intranasally administered recombinant influenza vaccine, uses an adenovector to achieve expression of the influenza antigen in the target cell, thereby potentially stimulating a broader and more rapid immune response than traditional influenza vaccines. Our Phase 2a trial evaluating NasoVAX started in September 2017 and was completed during 2018. Initial data, released in March 2018, indicated that NasoVAX was well-tolerated at all doses tested. Additionally, the achievement of 100% seroprotection and statistically significant increases in mucosal antibody at two of the three dose levels studied has set NasoVAX apart from other intranasally administered vaccines. Strong T-cell responses were also observed at the highest dose. This combination of serum antibody, mucosal antibody and T-cell responses provides the potential for improved ability to prevent infection and suggests that NasoVAX could have a greater impact on flu symptoms and shedding of the flu virus than currently approved influenza vaccines. All subjects were followed for an additional six months after vaccination to assess the durability of the antibody response and several subjects from the highest dose were also evaluated between 12 and 14 months after initial dosing for additional immunogenicity assessment. These new NasoVAX data, obtained from the group of 8 subjects that returned for analysis show that the immune response elicited by NasoVAX remained at seroprotective levels for at least 13 months. Durable responses on the order of 1 year are not expected from currently approved influenza vaccines and suggest that immune response induced by NasoVAX could be protective much longer than the current influenza vaccines.
Altimmune is a clinical-stage immunotherapeutics company focused on the development of products to stimulate robust and durable immune responses for the prevention and treatment of disease. HepTcell is a synthetic peptide immunotherapeutic candidate designed to break immune tolerance in chronic Hepatitis B infection. ALT-702, a TLR7/8 agonist conjugate, is an immunostimulant product candidate that has the potential to safely elicit or improve immune responses in a variety of therapeutic settings. NasoVAX, our influenza vaccine candidate, has unique characteristics that stimulate multiple arms of the immune system and offers the potential to stop infection and the spread of flu, while being easier to administer through an intranasal spray. NasoShield is a next-generation intranasal anthrax vaccine candidate that is intended to improve protection and safety while having favorable dosage and storage properties compared to other anthrax vaccines. By leveraging the complementary attributes of its proprietary technology platforms, Altimmune is able to design and develop immunotherapeutic products tailored to address a wide range of disease indications including both acute and chronic infections and cancer.