Brincidofovir

As of 2014, brincidofovir was in Phase III clinical trials for use in humans against cytomegalovirus and adenovirus, after testing for safety in over 1,000 human subjects,[6] and has received FDA Fast Track Designation for treatment of cytomegalovirus, adenovirus, and smallpox.[7] Chimerix announced in December 2015 that the Phase III trials for use of the drug in preventing cytomegalovirus infection in stem cell transplant patients had failed, and in February 2016 shut down two other late-stage trials for use of the drug in preventing infection after kidney transplants.

As of 2016, the company is planning on returning trials of the drug for use in stem cell transplant patients to Phase II, while continuing to advance a late-stage trial for use against adenovirus infections in patients suffering from weakened immune systems.[8]

On October 6, 2014, Chimerix received an FDA authorization for emergency investigational new drug applications of brincidofovir for the treatment of Ebola virus disease. Brincidofovir was administered to the first patient diagnosed in the Ebola virus disease outbreak in the US in 2014.[7][9] The patient was given the drug starting six days after hospital admission when he was already critically ill; he died four days later.[10][11] Brincidofovir was also given to Ebola patient Ashoka Mukpo at the Nebraska Medical Center, who had developed the disease and then was pronounced Ebola-free and released from the Center on 22 October 2014.[12]

In October 2014, Chimerix reported it had been given approval by the FDA to start Phase 2 trials in patients infected with ebolaviruses for brincidofovir's safety, tolerability, and efficacy.[13] A trial commenced during January 2015 in Liberia,[14] but was subsequently discontinued. Because of a lack of suitable subjects in Liberia, Oxford University and Médecins Sans Frontières planned to extend the trial to Sierra Leone, where there were still Ebola cases; but on the 30th of January 2015, the manufacturer decided to withdraw support for the trial and end discussion of future trials.[15][16]

Brincidofovir (CMX001) was the subject of widespread social media campaigning in 2014, which was then picked up by national news sources about a boy with an adenovirus infection following a bone marrow transplant.[17] The family requested legal access to the still-unapproved drug outside of any clinical trial, and Chimerix initially denied the request. After a short and intense media campaign, Chimerix got permission from the FDA to start a limited open-label trial which allowed the boy to receive the drug.[17] This media event sparked a debate on the ethics of using social media, the allocation of limited resources of a small company, and the emphasis on the individual over the group. The new use of any drug has the potential to interfere with the process to get the drug approved and widely marketed, through means such as consuming limited staff time that may be needed elsewhere – staff time that has the potential to save thousands of lives in the long-term, rather than one life now – overwhelming manufacturing capabilities, or by causing adverse effects or even death.[17] These adverse events are more likely during these programs, because the people seeking access are usually much sicker than most, and problems experienced by these people can result in an unfavorable and inaccurate perception of the drug's safety profile.[17] In this case, the boy recovered from the infection in 2014, and died in 2016 from complications of cancer.[18]

Brincidofovir is one of several experimental drugs administered to a small number of patients to treat Ebola virus disease during the 2014 outbreak. The WHO published a report on the ethics of using unregistered interventions to treat Ebola, where they concluded that "In the particular context of the current Ebola outbreak in West Africa, it is ethically acceptable to offer unproven interventions that have shown promising results in the laboratory and in animal models but have not yet been evaluated for safety and efficacy in humans as potential treatment or prevention."[19]

• BCX4430
• Favipiravir
• FGI-106
• JK-05
• Lamivudine
• TKM-Ebola
• ZMapp

• Kern, ER; Hartline, C; Harden, E; Keith, K; Rodriguez, N; Beadle, JR; Hostetler, KY (2002). "Enhanced inhibition of orthopoxvirus replication in vitro by alkoxyalkyl esters of cidofovir and cyclic cidofovir". Antimicrob. Agents Chemother. 46 (4): 991–5. doi:10.1128/aac.46.4.991-995.2002. PMC 127114. PMID 11897580.