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VX-787 Showed Significant Antiviral Activity and Reduced the Severity and Duration of Influenza Symptoms in Phase 2 Challenge Study
- Treatment with highest dosing regimen of VX-787 reduced viral shedding by 94 percent versus placebo; Duration of flu symptoms were reduced by nearly half -
- VX-787 is an investigational new class of medicine designed to directly inhibit replication of the influenza virus -
"There is an urgent need for new medicines targeting influenza that work
more quickly, address resistant and pandemic strains, and are effective
when taken more than two days after symptoms appear," said
About the Phase 2a Study
This double-blind, randomized, placebo-controlled Phase 2a study of
VX-787 enrolled and dosed 104 healthy people (72 in the VX-787 arms; 32
in the placebo arm) ages 18 to 45 who volunteered to be experimentally
exposed to an attenuated form of live H3N2 influenza A virus. H3N2 is a
common type of influenza virus, and was the most common type observed in
the 2012/2013 influenza season in
The primary objective of this study was to determine the effect of VX-787 on levels of the influenza virus by measuring the total area under the curve of viral titers (quantity of the virus shed in nasal secretions) over time. Viral shedding is a validated marker for assessing antiviral agents in proof-of-concept clinical studies in influenza. Higher total area under the curve (AUC) indicates greater shedding of the influenza virus from the upper respiratory tract, whereas lower total AUC indicates inhibition of, or decreased, viral shedding.
Secondary objectives of the study included safety and tolerability, as well as duration and severity of clinical symptoms. In the study, only people who developed influenza infection after exposure, as measured by detectable virus in nasal secretions or a pre-defined antibody response, were included in the efficacy analysis, whereas all study participants were included in the safety analysis. Of the 72 patients enrolled across the VX-787 treatment arms, 52 developed influenza infection. Of 32 patients enrolled in the placebo arm, 22 developed influenza infection.
Primary Endpoint: Across the VX-787 doses studied, a statistically significant dose response in reduction in viral shedding AUC was observed (p=0.036). In addition, over the seven days of observation, the 14 people in the highest dose group showed a total median AUC of 0.4 log10 virus compared to the 22 people who received placebo, who showed a total median AUC of 5.9 log10 virus, a difference that was statistically significant. These median AUC values reflect a 94 percent reduction in the amount of virus shed during the study for people treated with the highest dosing regimen of VX-787 compared to placebo.
Secondary Endpoints: In addition to reductions in total viral AUC, treatment with VX-787 in the highest dose group also resulted in statistically significant improvements in multiple clinical measures of influenza. People in this group experienced influenza-like symptoms for a median duration of 1.9 days, compared to 3.7 days for those who received placebo. In addition, there was a statistically significant decrease in the severity of influenza-like symptoms, as measured by AUC and peak severity of symptoms reported by participants in the study. Participants graded seven influenza-like symptoms on a scale of 0 to 3; this was summed to obtain a symptom severity score (maximum symptom severity score of 21.)
|Influenza-Like Symptoms||Placebo (n=22)||
1,200 mg / 600 mg* (n=14)
|Peak (mean; severity score)||3.4||
|Duration (median; days)||3.7||
|AUC (median; severity score over 7 days)||4.1||
* First dose was 1,200 mg for one day, subsequent doses were 600 mg QD for four days
** Statistically significant; p < 0.05
In this study, VX-787 was generally well-tolerated, and all participants completed treatment. There were no serious adverse events or adverse events that led to discontinuation of treatment. Overall, the most frequently reported class of adverse events in the VX-787 and placebo arms were those typically associated with influenza-like illness. In the development program to date, VX-787 has been dosed in approximately 170 people. The highest single dose given was 1,600 mg, and the longest duration of dosing was 800 mg QD for 10 days. In these studies, there were no serious adverse events, and no adverse events that led to treatment discontinuation.
VX-787 is an investigational medicine being developed by Vertex that is designed to directly inhibit replication of influenza A, including recent H1 (pandemic) and H5 (avian) influenza strains, based on in-vitro data. VX-787's mechanism represents a new class of potential medicines for the treatment of influenza, distinct from neuraminidase inhibitors, the current standard of care for the treatment of influenza. VX-787 is intended to provide a rapid onset of action and an expanded treatment window. VX-787, which was discovered by Vertex scientists, underscores the Company's expertise in antiviral drug development, beginning with early research in HIV and more recently in hepatitis C. Vertex has worldwide rights to develop and commercialize VX-787.
Each year in the U.S., more people die from influenza than die from
HIV/AIDS.i Often called "the flu," seasonal influenza is
caused by influenza viruses, which infect the respiratory tract.ii
The flu can result in seasonal epidemicsiii and can produce
severe disease and high mortality in certain populations, such as the
elderly.iv Each year, on average 5 to 20 percent of the U.S.
population gets the fluv resulting in more than 200,000
flu-related hospitalizations and 36,000 deaths.vi The overall
national economic burden of influenza-attributable illness for adults is
Vertex creates new possibilities in medicine. Our team discovers, develops and commercializes innovative therapies so people with serious diseases can lead better lives.
Vertex scientists and our collaborators are working on new medicines to cure or significantly advance the treatment of hepatitis C, cystic fibrosis, rheumatoid arthritis and other life-threatening diseases.
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Special Note Regarding Forward-Looking Statements
This press release contains forward-looking statements as defined in the
Private Securities Litigation Reform Act of 1995, including, without
limitation, Dr. Wright's statements in the second paragraph of this
press release and the statement regarding Vertex exploring collaborative
opportunities to support further development of VX-787. While the
company believes the forward-looking statements contained in this press
release are accurate, there are a number of factors that could cause
actual events or results to differ materially from those indicated by
such forward-looking statements. Those risks and uncertainties include,
among other things, the risks listed under Risk Factors in Vertex's
annual report and quarterly reports filed with the
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