Chimerix's CMX001 Resistance Data Presented at the 26th International Conference on Antiviral Research


DURHAM, N.C., May 16, 2013 (GLOBE NEWSWIRE) -- Chimerix, Inc. (Nasdaq:CMRX), a biopharmaceutical company developing novel, oral antivirals in areas of high unmet medical need, recently presented data demonstrating CMX001's high barrier to viral resistance in the prevention and treatment of cytomegalovirus (CMV) infection. The data were presented at the International Society for Antiviral Research's 26th International Conference on Antiviral Research (ICAR) held May 11-15, 2013 in San Francisco, CA. CMX001 is an investigational oral nucleotide analog lipid-conjugate that has a broad spectrum of antiviral activity against double-stranded DNA (dsDNA) viruses.

"These data support CMX001's use as first-line therapy for the prevention of CMV in immunocompromised patients," said M. Michelle Berrey, MD, MPH, Chief Medical Officer of Chimerix. 

The data were presented in oral sessions on Wednesday, May 15, 2013. Details on the presentations are as follows:

Rational Design of Nucleoside Phosphonates for Intracellular Delivery Using Lipid Conjugation

Chimerix's proprietary lipid antiviral conjugate technology has led to two clinical stage nucleotide analog lipid-conjugates, CMX001 and CMX157, with improved efficacy and safety profiles compared to the underlying parent molecules, cidofovir and tenofovir, respectively. Specifically, the lipid technology results in higher intracellular levels of the active antiviral, while avoiding the known kidney-related side effects of the parent molecule. By efficiently delivering the drug inside cells, the lipid technology allows for more of the active drug to be delivered to the site of viral replication while minimizing the amount of free drug in the plasma, which in turn decreases the risk of nephrotoxicity. Additionally, the lipid technology results in levels of the active antiviral that are detectable in the cells for a longer period of time after dosing. This may allow for less frequent dosing and a low pill burden, potentially important advantages for patients.

CMV Resistance Profile of CMX001

Resistance to CMX001 is slow to emerge in vitro and was not observed in treatment-naïve patients enrolled in Chimerix's Phase 2 study of CMX001 for the prevention of CMV reactivation in hematopoietic stem cell transplant (HSCT) recipients. In the Phase 2 study, different doses of CMX001 were explored for potential CMV prevention in at-risk patients.  Across a spectrum of doses of CMX001, there were no treatment-emergent mutations detected that are associated with phenotypic resistance to CMV antivirals. In a different patient population of heavily pretreated patients with life-threatening dsDNA viral infections, data from 215 patients enrolled in Chimerix's Expanded Access Study (Study 350) demonstrated that pre-existing viral resistance from exposure to other antivirals can cause cross resistance to CMX001 in vitro and can diminish virologic response. Specifically, mutations in the CMV polymerase (UL54) were associated with a decreased rate of CMV clearance.  However, the more common UL97 CMV phosphokinase mutations that are known to be associated with ganciclovir do not confer resistance to CMX001.

About CMX001

Chimerix's lead product candidate, CMX001, is a broad-spectrum oral nucleotide analog that blocks replication of all five families of dsDNA viruses that infect humans, including CMV, adenovirus (AdV), BK virus and herpes simplex viruses.  In a Phase 2 trial, CMX001 demonstrated potential clinical utility in prevention of CMV infection in high-risk patients who had received a HSCT.  Chimerix anticipates initiating SUPPRESS, its Phase 3 trial of CMX001 for the prevention of CMV infection in adults undergoing HSCT, in mid-2013.  In December 2012, Chimerix completed enrollment of a Phase 2 trial in pediatric and adult HSCT recipients evaluating CMX001 as a preemptive therapy for AdV disease, an often-fatal infection with no approved therapies.  Since 2009, Chimerix has made CMX001 available through a Compassionate Use Program to over 80 medical centers worldwide for the treatment of over 430 patients with life-threatening dsDNA viral infections and no alternative treatment.

Chimerix has received Federal funding for the development of CMX001 as a potential medical countermeasure against smallpox from the Biomedical Advanced Research and Development Authority, Office of the Assistant Secretary for Preparedness and Response, Office of the Secretary, Department of Health and Human Services, under Contract No. HHSO100201100013C.

About Chimerix

Chimerix is committed to the discovery, development and commercialization of novel, oral antiviral therapeutics designed to transform patient care in areas of high unmet medical need.  Chimerix's proprietary lipid technology has given rise to two clinical-stage nucleotide analog lipid-conjugates, CMX001 and CMX157, which have demonstrated the potential for enhanced activity and safety in convenient, orally administered dosing regimens.  Chimerix's second product candidate, CMX157, an oral nucleotide analog for the treatment of HIV infection, was licensed to Merck in July 2012.

Forward-Looking Statements

Statements contained in this press release regarding matters that are not historical facts are "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995.  Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements.  Such statements include, but are not limited to, statements regarding the use of CMX001 as first-line antiviral therapy, the advantages of Chimerix's proprietary lipid antiviral conjugate technology, the efficacy and resistance profile of CMX001 and its ability to provide a broad spectrum of antiviral activity and the positive impact of CMX001 on transplant recipients.  Risks that contribute to the uncertain nature of the forward-looking statements include: the accuracy of Chimerix's estimates regarding its ability to initiate the SUPPRESS trial; the success of the SUPPRESS trial and Phase 2 trials; the demonstrated efficacy of CMX001 in the SUPPRESS trial and Phase 2 trials; the accuracy of Chimerix's estimates regarding expenses and capital requirements; regulatory developments in the United States and foreign countries; Chimerix's ability to obtain and maintain intellectual property protection for CMX001; and the loss of key scientific or management personnel.  These and other risks and uncertainties are described more fully in Chimerix's filings with the Securities and Exchange Commission, including without limitation its Registration Statement on Form S-1 that was originally filed with the Securities and Exchange Commission on March 8, 2013, and the amendments thereto.  All forward-looking statements contained in this press release speak only as of the date on which they were made. Chimerix undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made.



            

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