Vaccines currently on the U.S. market primarily use aluminum salts as adjuvants, but some of the newer vaccines marketed outside of the U.S. such as GSK’s H1N1 vaccine use AS03, an oil-in-water emulsion and vitamin E combination. GSK’s Cervarix cervical cancer vaccine for HPV uses the company’s AS04 adjuvant, which consists of an aluminum salt and monophosphoryl lipid A.
MF59, the adjuvant in Novartis’ H1N1 vaccine, is also an oil-in-water emulsion; it can reportedly elicit a Th2 antibody response with a lower dose. Pfizer and Idera Pharmaceuticals have toll receptors under development for use as adjuvants. Antigenics’ QS-21 adjuvant is now in multiple clinical trials, including four Phase III trials.
Last year, Datamonitor published a report that reviews adjuvant technology for both prophylactic and therapeutic vaccines. Datamonitor sees a lower barrier for approval for therapeutic applications such as cancer and thinks that AS04’s performance in GSK’s product will have a crucial impact on prospects for future combination immunostimulatory adjuvants.
Crucell focuses on vaccines and proteins utilizing its PER.C6 cell line and its AdVac vector technology, which reportedly has the ability to mediate a strong T-cell immune response. Vaccines under development include yellow fever, flu, TB, malaria, Ebola, Marburg, and HIV. The firm’s strategic partners include Sanofi Pasteur, the vaccines division of sanofi-aventis, GSK, Novartis, and Johnson & Johnson, which recently purchased 18% of the company.
CSL has a broad commercial vaccine product line including an H1N1 vaccine and a Gardasil partnership with Merck. New flu vaccine programs are under way with Merck and Wyeth, now part of Pfizer. The company has also been working on an adjuvant called Iscomatrix, which consists of saponin, cholesterol, and phospholipids, and is currently in Phase II for flu.
Inovio Biomedical is focused on preventive and therapeutic DNA vaccines that utilize its SynCon construct technology and electroporation delivery. Its pandemic flu program is at the preclinical stage, and an HIV Pennvax-B program is in Phase I.
Ligocyte is focused on VLP (virus-like particle) technology, which is composed of multiple copies of a protein antigen that mimic the native virus. Norovirus is the initial target; Phase I trials are under way for the vaccine, which is formulated with the GSK’s MPL adjuvant.
Novavax is developing recombinant vaccines for infectious diseases, including H1N1 using VLP technology. R&D programs include H5N1, RSV, varicella zoster virus, and HIV. The company says that its manufacturing process will be higher yielding and less complex than current egg-based manufacturing.
Profectus Biosciences is a VC-funded firm that uses prime boost technology, which delivers plasmid DNA followed by a recombinant vesicular stomatitis virus vector. Viral disease targets include HCV, HPV, herpes simplex virus 2, and HIV.
Protein Sciences offers a baculovirus expression vector system for production of vaccines and proteins. Its FluBlok seasonal influenza vaccine completed Phase III studies and is currently under review at the FDA.
Vical develops vaccine and immunotherapy products based on its DNA delivery technology and a Vaxfectin adjuvant that is currently in a Phase I trial for H5N1. A CMV Phase II trial is being conducted for an immunotherapeutic vaccine.
Heavy R&D investment in vaccine technology over the past 10 years by governments, nonprofits, and commercial organizations has resulted in novel formulations, better delivery systems, and a variety of products to control infectious disease. Advances in cell culture and bioreactors combined with recombinant technology such as DNA and VPL vaccines will make manufacturing more cost effective and speed up the introduction of more new products. As vaccine products proliferate, and technologies gain clinical and regulatory acceptance, smaller innovative biotech companies will undoubtedly advance in the market.