Atea Pharmaceuticals, Inc.

Good afternoon, ladies and gentlemen. Welcome to the Atea Pharmaceuticals 3rd Quarter 2021 Financial Results Conference Call. At this time, all participants are in a listen-only mode. Following the formal remarks, we will open the call up for your questions. I would now like to turn the call over to Joneigh Barnes, Senior Vice President of Investor Relations and Corporate Communications at Atea Pharmaceuticals. Please proceed.

Thank you, Operator. Good afternoon, everyone, and welcome to Attea Pharmaceuticals' third quarter 2021 financial results conference call. This afternoon, we issued a press release which outlines the topics we plan to discuss. You can access the press release as well as the slides that we'll be reviewing today by going to the investor section of our website at ir.atteapharma.com. With me today from Attea, our chief executive officer and founder, Dr. John-Pierre Sommadosi. Chief Development Officer, Dr. Janet Hammond, Chief Financial Officer and Executive Vice President of Legal, Andrea Porcarin, and our Chief Commercial Officer, John Bavarica. They will all be available for the Q&A portion of today's call. Before we begin the call, as outlined on slide two, I would like to remind you that today's discussion will contain forward-looking statements that involve risk and uncertainties. These risks and uncertainties are outlined in today's press release and in the company's recent filings with the Securities and Exchange Commission, which we encourage you to read. Our actual results may differ materially from what is discussed on today's call. With that, I'll now turn the call over to Jean-Pierre.

Thank you, Joné. Good afternoon, everyone, and thank you for joining us today. In addition to the financial results, we have a number of updates for 8527 to review. including an amendment to the Phase III Morning Sky trial protocol and a plan to accelerate its enrollment, quantitative infectious virus assay data from the Munson trial, confirming potent and rapid antiviral activity for 8527, and new in vitro data for 8527 demonstrating potent antiviral activity against a major variance of concern or interest, including Delta. I will begin on slide three. AT527, our already administered product candidate for COVID-19, is a direct acting antiviral agent derived from our purine nucleotide product platform. AT527 is designed to protect against disease progression and the development of long COVID complications. Given the evolving dynamics of COVID-19, which is becoming endemic, Medical intervention and all therapeutics in particular will be essential in stemming the tide of this pandemic and future surges. 85 to 7 targets viral RNA polymerase, a highly conserved enzyme critical to viral replication and transcription. Uniquely, 85 to 7 has a mechanism with dual targets. It is a chain terminator, without introducing new mutations in the virus, and it also inhibits NIRAN, thus providing the potential to create a high barrier to resistance and antiviral activity across variants, as we will share with you in a few minutes. In all studies, 8527 was shown to be generally safe and well-tolerated. On particular note, 8527 is not mutagenic with no reproductive toxicity, and it's non-theratogenic. We expect minimal drug-drug interaction since AT527 is a weak inhibitor of cytochrome P453A, and no dose adjustment is expected for co-administration of drugs that are CYP3A substrate, which account for the metabolism of more than 50% of clinically relevant drugs, so this should make our drug candidate prescriber friendly. On slide four, COVID variants of concern continue to create new challenges for treatment and prevention. These variants can also make the execution and evaluation of clinical trial results more challenging because of the impact and differences in viral kinetics as well as clinical symptoms. Ongoing SARS-CoV-2 genomic surveillance worldwide has improved our ability to rapidly identify such variants. As you can see on this chart, almost 6,000 variants have been sequenced with an outstanding number. The evolution of the virus will make COVID-19 endemic with the ability to continue circulating for years to come. SARS-CoV-2 variants of interest have been associated with increased transmissibility, neutralization resistance, and disease severity. The continuing spread of Delta has led to a new subtype called AY.4.2, or Delta Plus, which carries additional mutations. Although the original Delta variants remain the most dominant on a global basis, this new mutant now accounts for 14% of infections in the UK, up from less than 4% just early September, and is more likely contributing to the recent surge of the fifth wave of COVID in Western and Eastern Europe and other global areas. Preliminary evidence suggests that Delta Plus spreads between 12% and 15% more frequently among household members compared with other Delta viruses and will likely become an important strain, including in the U.S. Moving to slide six. As you know, we have previously shown that 8511, the free base of 8527, is a potent inhibitor of SARS-CoV-2 in vitro. The average EC90 in primary human airway epithelial cells against the original virus isolated in early 2020 was around 0.5 micromole, with a five-fold assay, approximately assay-to-assay variability, as you can see in this slide. We recently evaluated our drug candidate against the major variants of concern or interest, including alpha, gamma, epsilon, and more recently, delta. Consistent with its dual mechanism of action, AT511 maintained its potency against all the variants tested, including delta. We believe that this data confirmed the key mechanistic advantage of this drug candidate which target the highly conserved viral RNA polymerase. In fact, we have analyzed over 3 million SARS-CoV-2 sequences deposited in the database to date and found that less than 0.01% was mutation near the active site of the SARS-CoV-2 polymerase. With that, I will now turn the call over to Janet for a more detailed review of our clinical programs.