Unprecedented Viral Protection

At Chimerix, we’re on a mission to discover and develop much-needed medicines that protect immunocompromised patients from potentially devastating viral infections. For people with weakened immune systems and patients undergoing bone marrow transplants, common viruses can quickly become life-threatening.

More than 70,000 hematopoietic cell transplants (HCT, or bone marrow transplants) are performed each year worldwide, most frequently to treat patients with certain cancers of the blood and bone marrow, or to address genetic diseases. Due to chemotherapy and the immune suppression associated with HCT, patients are highly susceptible to viral, bacterial and fungal infections. These complications are a significant cause of morbidity and mortality in the months following the transplant, and too often the high risk of infection in the first year after transplant results in patients and their families deciding against having a potentially curative transplant.

Our goal is to develop safe and effective therapies to protect these patients from the dangers of life-threatening infections so they can remain on the path to recovery.

Cytomegalovirus (CMV) is a member of the herpesvirus family and remains a significant cause of viral infections in transplant recipients. A majority of adults in the U.S. have evidence of a prior infection with CMV, which establishes a dormant or latent infection that cannot be cleared; most individuals have an immune system that is able to prevent CMV from reactivating and causing disease. In individuals with weakened immune systems—such as transplant recipients—CMV commonly reactivates during the first weeks following the transplant. This leads to infection of the lungs or other organ systems and can increase the risk of other viral, bacterial and fungal infections. Currently, no therapies are approved for the prevention of CMV in hematopoietic cell transplant (HCT) recipients because of known toxicities associated with available CMV antivirals, including bone marrow suppression and renal impairment.
Adenovirus causes upper respiratory infections, including the common cold, in individuals with a functional immune system. However, in people with a weakened immune system, such as patients who have undergone a transplant, adenovirus can lead to life-threatening infections, including pneumonia and hepatitis. Disseminated adenovirus disease can be associated with a mortality rate of up to 80% in patients who are undergoing hematopoietic cell transplant (HCT, also called bone marrow transplant).5 Currently, no therapies are approved for the treatment of adenovirus.
Smallpox is estimated to have killed more than one billion people worldwide prior to its eradication, declared by the World Health Organization in 1980 following a global vaccination campaign. Smallpox stocks remain for research purposes in the U.S. and Russia; however, undeclared stocks are suspected to exist. Routine smallpox vaccination programs were discontinued after the global eradication, and with no antiviral agent approved for the treatment of smallpox, the U.S. population may be susceptible to a bioterror attack. Chimerix is working with the Biomedical Advanced Research and Development Authority (BARDA) to develop a medical countermeasure to treat potential smallpox outbreaks in the event of bioterror attacks or accidental release.

Technology that Inspires Drug Development

The ability to prevent life-threatening viruses like cytomegalovirus (CMV) in vulnerable hematopoietic cell transplant (HCT) recipients may be possible. Our proprietary technology has led us to two products currently showing great potential: brincidofovir (CMX001) and CMX157. Brincidofovir, a clinical-stage lipid conjugate nucleotide analog , has demonstrated in vitro antiviral activity against all five families of DNA viruses that affect humans, including CMV, adenovirus, BK virus and herpes simplex viruses, in an orally administered dosing regimen. CMX157, a novel lipid acyclic nucleoside phosphonate, is active against hepatitis B virus (HBV) and more than 200-fold more potent in vitro versus tenofovir against all major HIV subtypes resistant to current therapies.

Through work to date, we see opportunities to apply the lipid conjugate technology to other drug and disease categories that are also characterized by a need for effective treatments.