Merck & Co. has added another experimental vaccine to its pipeline, paying $50 million to Opko Health for a preclinical candidate aimed at the Epstein-Barr virus, which causes mononucleosis and is linked to multiple sclerosis and some types of cancer.
Opko said Wednesday the deal could pay out another $872.5 million based on reaching certain developmental and commercial milestones. The two companies will jointly develop the vaccine until the Food and Drug Administration grants permission to begin clinical testing, at which point Merck will be responsible for clinical and regulatory activities.
The vaccine, dubbed MDX-2201, is a newer kind of shot. Called a “nanoparticle” vaccine, it uses iron-bearing blood protein called ferritin, on which engineered proteins that simulate a viral infection are expressed. Opko said its platform can show the immune system as many as 24 different proteins. In the case of MDX-2201, four different proteins related to viral entry into immune and epithelial cells are expressed.
Opko has one marketed product, a treatment for elevated parathyroid hormones in people with chronic kidney disease. The company gained MDX-2201, along with the nanoparticle vaccine platform, when it acquired ModeX Therapeutics in May 2022 in a $300 million all-stock deal.
ModeX’s leadership team included Elias Zerhouni, a former National Institutes of Health director; Gary Nabel, founding director of NIH’s Vaccines Research Center; and Alexis Borisy, a biotech entrepreneur and venture capitalist. Following the deal, the three became, respectively, Opko’s president, chief innovation officer and a director.
In addition to the Epstein-Barr vaccine, the ModeX acquisition gave Opko access to “multispecific” antibodies for HIV, COVID-19 and types of cancer.
Epstein-Barr is a common virus that infects most people but doesn’t always cause acute health episodes. Research suggests people with multiple sclerosis and some types of lymphomas are more likely to have been infected with the virus. Preventing infections could therefore have some long-term health benefits in addition to preventing cases of mononucleosis.
Opko shares trader higher on Wednesday morning following the announcement.
Merck markets Gardasil, a vaccine that prevents human papilloma virus, another pathogen that is linked to cervical and oral cancers.
Merck has also teamed up with another vaccines manufacturer, Moderna, pairing immunotherapy Keytruda with the biotech’s mRNA-vased vaccine for melanoma. Moderna hopes to gain FDA accelerated approval based on Phase 2 data.