What is Mapp Biopharmaceutical?
Mapp Biopharmaceutical is a small business formed in 2003 to develop monoclonal antibodies for neglected infectious diseases and as countermeasures for biodefense threats. It is fully owned by its two scientist founders, with a commitment to develop therapeutics that advance public health even in the absence of an established commercial market. Without outside investors, Mapp can prioritize the underlying science and its public health mission rather than focusing on financial returns.
Mapp operates a laboratory in San Diego with scientists experienced in the discovery, engineering and characterization of monoclonal antibodies, and multiple specialized teams with extensive experience across all pillars of advanced research and development. This enables Mapp to manage the full drug-development lifecycle, from discovery through FDA licensure.
In addition to MBP134, Mapp has candidates for pan-marburgviruses and Nipah virus in advanced development and a wide range of earlier candidates for priority threats such as hantavirus, Crimean Congo Hemorrhagic Fever virus, botulinum neurotoxins, ricin and more.
What is MBP134?
MBP134 is an investigational monoclonal antibody cocktail that targets the surface glycoproteins of several filoviruses. The two monoclonal antibodies that make up MBP134 were isolated from a survivor of the 2014-2016 outbreak of Zaire ebolavirus (EBOV) in West Africa. Mapp used a process called “affinity maturation” to broaden the neutralizing activity of MBP134 to cover all known pathogenic ebolaviruses affecting humans.
How is MBP134 different from previously approved Ebola therapeutics?
Currently approved Ebola therapeutics were developed against Zaire ebolavirus(EBOV) and, as such, are approved only for use in preventing infections or treating disease caused by that virus. MBP134 was specifically designed with the goal of broader activity across multiple ebolavirus species.
Which viruses is MBP134 intended to target?
MBP134 was designed to target multiple members of the ebolavirus genus, including all Ebola viruses that are known to cause disease in humans. Laboratory in vitro studies confirm that it neutralizes Zaire ebolavirus (EBOV), Sudan ebolavirus (SUDV), Reston ebolavirus (RESTV), Tai Forest ebolavirus (TAFV), Bombali ebolavirus (BOMV) and Bundibugyo ebolavirus (BDBV), which is the species currently circulating in the Democratic Republic of the Congo (DRC). In vivo studies demonstrate that MBP134 protects against Zaire ebolavirus, Sudan ebolavirus and Bundibugyo ebolavirus in relevant preclinical models (protection against other species of ebolavirus has yet to be tested in vivo). While this suggests that MBP134 may provide clinical benefit to patients infected with one of these viruses, the ongoing PARTNERS trial in DRC represents the first opportunity to evaluate MBP134 in a human clinical study specifically designed to determine clinical efficacy.
Is MBP134 approved for use against ebolaviruses?
No, MBP134 is an investigational product and has not been approved by the U.S. Food and Drug Administration (FDA) or other regulatory authorities for use outside of well-controlled clinical trials or compassionate use scenarios. As such, it can only be used in a clinical trial or compassionate use setting, with authorization from all relevant regulatory, ethics and public health authorities.
Has MBP134 been tested for safety in humans?
Yes, MBP134 has undergone Phase 1 clinical evaluation to assess safety and pharmacokinetics in healthy volunteers. The drug was found to be safe and well tolerated in this study.
Is MBP134 being used in the current Bundibugyo outbreak?
Yes, MBP134 has been used as a treatment for patients with Bundibugyo Virus Disease and as post-exposure prophylaxis for individuals with high-risk exposures to the Bundibugyo virus, all under compassionate use provisions authorized by local regulatory officials. MBP134 is also included in the WHO and Oxford University PARTNERS trial. This randomized, controlled trial (RCT) is designed to evaluate safety and potential clinical benefit of MBP134 and other investigational drugs when administered to patients with confirmed Bundibugyo virus disease.
Is MBP134 available commercially?
No. MBP134 is an investigational product and is not commercially available.
What role has the U.S. government played in development?
Development of filovirus countermeasures has involved collaboration among academic institutions, industry, and public-sector partners, including support from U.S. government agencies. The Defense Threat Reduction Agency (DTRA) funded the discovery of MBP134 and the Biomedical Advanced Research and Development Authority (BARDA) is actively funding its advanced development through FDA licensure and ongoing manufacture for outbreak response. All doses of MBP134 currently available for clinical use in the PARTNERS trial and compassionate use settings have been donated by the U.S. Government’s Department of Health and Human Services.
What is the current development status of MBP134 and how soon might MBP134 be licensed by the FDA if clinical benefit is demonstrated?
Development activities remain ongoing. As is standard for investigational therapeutics, future development steps will depend on scientific, regulatory, operational, and funding considerations. If clinical benefit is demonstrated in the PARTNERS trial, US licensure will require analysis of all clinical data, manufacturing validation, assembly of a Biologics License Application, and formal review by the FDA. Mapp’s best estimate of timeline for these activities is approximately 12 to 24 months from the time PARTNERS data become available for regulatory submission.
Are there doses of MBP134 available for use outside of the PARTNERS trial if it is shown to have clinical benefit for patients with Bundibugyo Virus Disease?
Yes, the current supply of MBP134 is sufficient to continue the uninterrupted supply to the PARTNERS trial and additional use outside of the PARTNERS trial, possibly under the MBP134 Expanded Access Protocol which is active now in DRC and could be activated in other countries if the outbreak expands.
Could MBP134 be made available to every patient in the current outbreak?
It is not yet possible to know how many patients could ultimately receive MBP134 during the current outbreak. The current supply is sufficient to continue uninterrupted supply to the PARTNERS trial and to support additional use outside the trial if clinical benefit of MBP134 is declared. Mapp and BARDA have initiated manufacturing activities intended to further increase available supply.
The number of patients who could receive MBP134 will depend on several factors, including the size and duration of the outbreak, where new cases occur, available supply at different points in time within the outbreak, and whether patients reach healthcare settings equipped to administer an investigational intravenous therapeutic.
MBP134 must be administered under an authorized clinical trial or compassionate-use pathway in a setting with appropriately trained healthcare personnel, infusion and monitoring capabilities, and procedures for informed consent. These capabilities are generally available in established Ebola Treatment Units (ETUs), but not all patients reach or receive care in an ETU.
Mapp and its partners are therefore working both to increase available supply and to make MBP134 accessible through appropriate clinical and regulatory pathways as the outbreak evolves.
Has Mapp taken any steps to increase inventory of MBP134 in response to the current outbreak?
Yes, shortly after the WHO notification of the outbreak in DRC and Uganda, Mapp began filling existing bulk drug substance into vials suitable for clinical use. Following completion of packing, labeling and release, these additional treatment courses have started to become available for clinical distribution and use this year. Mapp has also initiated new manufacturing campaigns which will significantly increase supply in Spring 2027. Each of these efforts is being supported by BARDA.
Does Mapp expect to take any additional steps to increase inventory of MBP134?
Yes, Mapp is currently in discussions with the US government to support additional manufacturing of MBP134.
While the US government has been the only funder of MBP134 development and manufacturing to date, Mapp is not limited in any way by this partnership. Since the beginning of the current outbreak, Mapp has responded to inquiries from other countries and global funding agencies interested in understanding potential manufacturing partnerships that would build additional supply of MBP134 beyond the stockpile held by the US government. Mapp is in late-stage discussions with one such country that would complete technology transfer and build additional manufacturing capacity outside of the US. While Mapp has not received a formal request for manufacturing or technology transfer proposals from other interested parties, we remain ready to discuss new partnerships should resources be made available for additional manufacturing.
What is Mapp doing to promote equitable access to MBP134?
Equitable access to life-saving therapeutics is strongly aligned with Mapp’s company philosophy and core principles – Mapp works to develop therapeutics for pathogens for which there are currently no significant commercial markets and, in many cases, disproportionally affect low- and middle-income countries (LMICs). In the spirit of equitable access, all new partnership agreements will include terms confirming that a significant portion of doses manufactured under these agreements be reserved for donation to LMICs impacted by the spread of Bundibugyo virus.
If clinical benefit is demonstrated for MBP134, Mapp will continue to work closely with the US government to facilitate any future donations of MBP134 to impacted nations. In parallel, Mapp will seek to expand availability of MBP134 in Ebola-affected countries under an equitable access model designed to ensure that ability to pay does not determine patient access. Mapp will work with affected countries, WHO, funders, procurement organizations and manufacturing partners to establish sustainable pricing, sufficient emergency inventory, manufacturing readiness and mechanisms for replenishment. Mapp will also consider technology transfer where these measures would materially improve sustainable access and appropriate financing, manufacturing capability, quality oversight and regulatory arrangements are in place.
Successful implementation of this strategy will require long-term commitments from public and philanthropic funders to finance procurement, stockpiling, replenishment, manufacturing readiness and other costs that cannot reasonably be supported by the small and episodic commercial market for Ebola disease therapeutics.