• AT-527 is a novel pan-genotypic purine nucleotide prodrug NS5B polymerase inhibitor which has been safe and well tolerated in this ongoing multiple part trial
• AT-527 exhibits potent antiviral activity in genotype (GT)-1b and GT-3 hepatitis C virus (HCV) infected patients with once-daily (QD) dosing of 550 mg for 7-days
• Preliminary data suggest that AT-527 has potent and equivalent antiviral activity in both cirrhotic and non-cirrhotic (NC) HCV-infected patients

Atea Pharmaceuticals, Inc., a biopharmaceutical company engaged in the development of next-generation therapeutics for the treatment of hepatitis C and other single stranded RNA viral infections, today reported positive data from its ongoing clinical trial of AT-527 in patients with GT-1b and GT-3 HCV infection. The company will present the data today at The International Liver Congress(TM) 2018 sponsored by the European Association for the Study of the Liver taking place in Paris, France.

“Although the introduction of new therapies has improved cure rates in recent years, hepatitis C continues to represent a serious global health burden, particularly within more difficult-to-treat patient populations. Given the limitations of currently available agents, we are very excited about the emerging clinical profile of AT-527, a novel, highly differentiated purine nucleotide prodrug, which has an attractive safety profile and very significant antiviral potency.  Most notably, preliminary data indicate that AT-527 exhibits potent antiviral activity, regardless of genotype or cirrhosis status in HCV-infected subjects,” stated Jean-Pierre Sommadossi, PhD, Atea’s Founder, Chairman and Chief Executive Officer.

Poster No. THU-341

Title:  AT-527, a pan-genotypic purine nucleotide prodrug, exhibits potent antiviral activity in subjects with chronic hepatitis C

Date/Time:  Thursday, April 12, 2018; 9:00 am – 5:00 pm CET

A summary of the data to be presented shows a mean maximum HCV RNA reduction of 2.3 log₁₀ IU/mL after a single dose, and 4.4 log₁₀ IU/mL after 7 days of dosing, of AT-527 in NC GT-1b HCV-infected subjects.  A mean reduction of 2.4 log₁₀ IU/mL after first dose and 4.6 log₁₀ IU/mL after 7 days of dosing was achieved in NC GT-3 HCV-infected subjects, respectively.  In ongoing cohorts, antiviral activity in Child Pugh A cirrhotic GT-1b/3 HCV infected subjects was similar to NC GT-1b and NC GT-3 cohorts.  E_max modeling confirms the clinical observation that 550 mg AT-527 QD will produce maximum efficacy.  No serious adverse events, dose-limiting toxicities or premature discontinuations were observed.