On February 21, 2023, eFFECTOR Therapeutics, Inc. (the “Company” or “eFFECTOR”) announced top-line results from its Phase 1b clinical trial of zotatifin for the treatment of COVID demonstrating favorable safety results as well as positive trends in several measures of antiviral activity. The Company also presented preclinical data that demonstrated the breadth of zotatifin’s activity against RNA viruses. These results were presented at the 30th Conference on Retroviruses and Opportunistic Infections on February 20, 2023.
The primary objective of the trial was to evaluate safety of zotatifin in subjects with mild-to-moderate COVID. Zotatifin was generally well tolerated at all doses, with injection site reactions from the sub-cutaneous route (all Grade 1 or 2) being the only adverse event showing a potential relationship to zotatifin dose. Secondary and exploratory objectives included evaluation of antiviral activity in nasal and saliva samples and pharmacokinetics (“PK”). Trends in antiviral activity favoring zotatifin over placebo were seen by several assessments. In particular, in saliva, which was sampled more frequently than nasal cavity, virus level undetectability (“VLU”) was achieved approximately twice as fast in the zotatifin-treated subjects compared to placebo, with a median time to VLU of three days for zotatifin in comparison to seven days for placebo. The Hazard Ratio (“HR”) for achieving VLU in saliva was 2.83 (95% confidence intervals 0.64, 12.5; p=0.13) in favor of zotatifin. Zotatifin administered by the sub-cutaneous route showed very similar PK parameters compared to IV administration in other trials, supporting continued development of zotatifin by the sub-cutaneous route. The half-life of zotatifin was measured to be approximately 4 days (across all dosing groups), supporting further development of zotatifin as a single administration to treat COVID.
In the randomized, double-blind, placebo-controlled dose escalation trial, 27 subjects received zotatifin at doses ranging from 0.01 to 0.035 mg/kg and nine subjects received placebo. At the outset of the trial, one patient received zotatifin and one patient received placebo by intravenous administration. All other subjects (n=34) received study drug by sub-cutaneous injection. Enrolled subjects had mild or moderate COVID and were positive for SARS-CoV-2 RNA or antigen within 7 days of randomization. The trial was conducted in collaboration with the Quantitative Biosciences Institute (“QBI”) at the University of California, San Francisco (“UCSF”), which holds a $5 million cooperative agreement sponsored by the Defense Advanced Research Projects Agency.
The Company also presented results from preclinical studies in which zotatifin was active against numerous COVID isolates and other coronaviruses and was 10-100 times more potent, than several agents authorized by the U.S. Food and Drug Administration for treatment of COVID, based on concentrations required to achieve comparable reductions in virus yield and protection from virus-induced cytopathic effects in cell-based assays.
Forward-Looking Statements
eFFECTOR cautions you that statements contained in this current report regarding matters that are not historical facts are forward-looking statements. The forward-looking statements are based on our current beliefs and expectations and include, but are not limited to, statements regarding: the future clinical development of zotatifin the potential of zotatifin as a treatment for COVID, diseases caused by other coronaviruses and in oncology; expectations of the COVID market opportunity; and the potential therapeutic benefits of our product candidates. Actual results may differ from those set forth in this current report due to the risks and uncertainties inherent in our business, including, without limitation: interim results of a clinical trial are not necessarily indicative of final results and one or more of the clinical outcomes may materially change as patient enrollment continues, following more comprehensive reviews of the data and as more patient data becomes available; potential delays in the commencement, enrollment and completion of clinical trials; additional disruptions to our operations from the COVID pandemic, including clinical trial and manufacturing delays; our dependence on third parties in connection with product manufacturing, research and preclinical and clinical testing; the results of preclinical studies and early clinical trials are not necessarily predictive of future results; the success of our clinical trials and preclinical studies for our product candidates is uncertain; we may use our capital resources sooner than expected and they may be insufficient to allow clinical trial readouts; regulatory developments in the United States and foreign countries; unexpected adverse side effects or inadequate efficacy of our product candidates that may limit their development, regulatory approval and/or commercialization, or may result in recalls or product liability claims; our ability to obtain and maintain intellectual property protection for our product candidates; and other risks described in our prior filings with the Securities and Exchange Commission. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof, and we undertake no obligation to update such statements to reflect events that occur or circumstances that exist after the date hereof. All forward-looking statements are qualified in their entirety by this cautionary statement, which is made under the safe harbor provisions of the Private Securities Litigation Reform Act of 1995.
