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International symposium reports on the use of antivirals in patients with H5N1
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MISSISSAUGA, ON, March 4 /CNW/ - Physicians from countries affected bythe deadly H5N1 influenza virus (bird or avian flu) have presented casereports about antiviral use in patients infected with H5N1, includingtreatment with the oral antiviral TAMIFLU(R) (oseltamivir). The physicians'reports were revealed this week at the International Symposium on RespiratoryViral Infections (ISRVI) in Singapore.(1)</PRE>
TAMIFLU is approved for both the treatment and post-exposure prevention(prophylaxis) of influenza in adults and in children one year and older.Studies supporting the approval of TAMIFLU are based in seasonal influenza.The magnitude of effect of TAMIFLU in treating and preventing novel strains ofinfluenza (such as those that may be involved in a pandemic or associated withavian flu) cannot be predicted as it has not been studied or approved in apandemic scenario. The World Health Organization (WHO) has recommended thathigher doses and longer treatment durations may be required to combat novelstrains of influenza.</PRE>
According to the WHO, the H5N1 virus has already killed 234 people in 12countries.(2) In the most recent clinical management guidelines issued by theWHO, TAMIFLU remains the primary antiviral agent of choice for the treatmentof H5N1 virus infections.(3) Symposium findings In Indonesia, of the total of 119 H5N1 human cases reported, 22 survived- an 18 per cent survival rate overall. Of the 119, 33 patients received noTAMIFLU, all of whom died. TAMIFLU was administered to the other 86 patients,with a 26 per cent survival rate overall. Time from onset of illness toinitiation of treatment appeared to influence survival. Of the two patientswho received TAMIFLU within 24 hours of illness onset, both survived. If giventhe drug within four days, 55 per cent survived (6/11), and 35 per centsurvived if given TAMIFLU within six days (13/37).(4) The survival rate ofthose receiving it later than six days after illness onset was 18 per cent(9/49).(2)</PRE>
Recent information about eight Vietnamese patients infected with H5N1 wasalso presented. All eight patients received TAMIFLU, however, all eightpatients presented to the hospital later than five days after onset ofillness. Only three of the eight patients survived reinforcing that treatmentbenefit is reduced for patients that receive the drug later in the course ofillness.(4),(5) In two patients who were unable to take the drug orally due tothe severity of their illness, physicians administered the drug by nasogastrictube and found it was well absorbed and there was a reduction in H5N1 virus inthese patients. Susceptibility of circulating H5N1 strains to TAMIFLU These clinical findings are supported by animal data, also presented atISRVI, which shows that oseltamivir treatment was effective against H5N1influenza viruses representing different clades/subclades. However, higherdoses were required for the more pathogenic H5N1 viruses.(6)</PRE>
"Multiple factors can affect the susceptibility of antiviral therapy withhighly pathogenic H5N1 influenza viruses and it is reassuring thatoseltamivir, in mouse models, demonstrates activity even to the mostpathogenic circulating strains," comments study author Dr. Elena Govorkova,St. Jude Children's Research Hospital, Memphis, US. "Antiviral drugs are anessential component for the early control of an influenza pandemic."</PRE>
Data also confirms the low level of resistance reported to-date withTAMIFLU to H5N1 avian influenza in the field; there are only five cases ofpublished reports of H5N1 resistance or reduced susceptibility to TAMIFLU todate.(7),(8),(9) Laboratory results have shown 96 per cent of H5N1 strains (53out of 55) tested in the laboratory were sensitive to TAMIFLU.(10)</PRE>
This compares to the around 14 per cent of isolates tested this year ofthe seasonal influenza A H1N1 virus showing resistance to TAMIFLU, reported atthe conference.(11) It is important to note that these increased levels ofresistance have only been reported spontaneously in this year's H1N1 (SolomonIslands) seasonal strain, and not an avian strain such as H5N1, and not inpatients who have been administered TAMIFLU.(12)</PRE>
"Currently, we are seeing that TAMIFLU has been used as part of theclinical management of patients infected with H5N1 with only isolated cases ofresistance being reported," comments Dr. David Reddy, Global Pandemic TaskForce Leader at Roche. "This is reassuring for governments that havestockpiled TAMIFLU for pandemic use. It is, however, critical that both Rocheand the medical community remain vigilant so that we can understand thismutating virus and be best prepared for defence against a potential pandemicstrain."</PRE>
Roche has undertaken several research initiatives to study the use ofTAMIFLU against the evolving H5N1 avian influenza virus, includingcollaborations with the National Institutes of Health (NIH), the SoutheastAsia Influenza Clinical Trials Research Network, and other researchinstitutions. Note to editors: Difference between a pandemic strain of influenza and seasonal influenza A pandemic strain of influenza is always of the A variety and is acompletely new strain to which there will be no immunity. A seasonal strain ofinfluenza is one that has previously been circulating, which may have changedslightly (antigenic drift) and to which a level of immunity exists. About pandemic influenza An influenza pandemic occurs when a new strain of influenza A virusappears, against which the human population has no immunity resulting inseveral, simultaneous epidemics worldwide with enormous numbers of deaths andillness. The most severe influenza pandemics to date include: 'Spanish flu' A(H1N1): 1918 caused in excess of 30 million deaths worldwide; 'Asian flu' A(H2N2): 1958 caused one million deaths worldwide; 'Hong Kong flu' A (H3N2):1968 caused 800,000 deaths worldwide in six weeks. The WHO believes that weare as close to the next pandemic as we have been at any time in the past 37years, with two of the three widely-recognized prerequisites for a humanpandemic met to date in the avian influenza outbreak in East Asia. Firstly, anew influenza virus strain has emerged (H5N1), and secondly, the virus hasspread to humans. The final barrier will be the effective transmission of thevirus from human to human. About TAMIFLU TAMIFLU is designed to be active against all clinically relevantinfluenza viruses and works by blocking the action of the neuraminidase (NA)enzyme on the surface of the virus. When neuraminidase is inhibited, thespread of the virus to other cells in the body is inhibited. It is licensedfor the treatment and prophylaxis of influenza in children aged one year andabove and in adults. The most frequently reported adverse events in clinicalstudies were nausea, vomiting, and diarrhea. TAMIFLU is available for thetreatment of influenza in more than 80 countries worldwide.</PRE>
TAMIFLU was approved based on studies in seasonal influenza. Themagnitude of effect of TAMIFLU in treating and preventing novel strains ofinfluenza (such as those that may be involved in a pandemic or associated withavian flu) cannot be predicted. The WHO has recommended that higher doses andlonger duration may be required. Roche and Gilead TAMIFLU was invented by Gilead Sciences and licensed to Roche in 1996.Roche and Gilead partnered on clinical development, with Roche leading effortsto produce, register and bring the product to the markets. Under the terms ofthe companies' agreement, amended in November 2005, Gilead participates withRoche in the consideration of sub-licenses for the pandemic supply of TAMIFLUin resource-limited countries. To ensure broader access to TAMIFLU for allpatients in need, Gilead has agreed to waive its right to full royaltypayments for product sold under these sub-licenses. About Roche Headquartered in Basel, Switzerland, Roche is one of the world's leadingresearch-focused healthcare groups in the fields of pharmaceuticals anddiagnostics. As the world's biggest biotech company and an innovator ofproducts and services for the early detection, prevention, diagnosis andtreatment of diseases, the Group contributes on a broad range of fronts toimproving people's health and quality of life. Roche is the world leader inin-vitro diagnostics and drugs for cancer and transplantation, a market leaderin virology and active in other major therapeutic areas such as autoimmunediseases, inflammation, metabolism and central nervous system. << Additional information - Roche Health Kiosk, Influenza: www.health-kiosk.ch/start_grip.htm - About TAMIFLU: www.roche.com/med_mbTAMIFLU05e.pdf - About influenza: www.roche.com/med_mbinfluenza05e.pdf - WHO: Global influenza programme: www.who.int/csr/disease/influenza/en/ - WHO: Avian flu: www.who.int/mediacentre/factsheets/avian_influenza/en/ References (1) Antivirals and therapeutics session, X International symposium on Respiratory Viral infections, Singapore, Sunday 2nd March 2008 (2) World Health Organization. Cumulative Number of Confirmed Human Cases of Avian Influenza A/(H5N1) Reported to WHO. 28 February 2008 http://www.who.int/csr/disease/avian_influenza/country/cases_table_2008_02_28/en/index.html (3) http://www.who.int/csr/disease/avian_influenza/guidelines/ClinicalManagement07.pdf (4) Sedyaningsih ER. The Indonesian Experience, X International symposium on Respiratory Viral infections, Singapore, Sunday 2nd March 2008 (5) Wertheim HFI. The recent Vietnamese Experience, X International symposium on Respiratory Viral infections, Singapore, Sunday 2nd March 2008 (6) Govorkova E. Influenza Antivirals in H5N1 Disease, Animal Model, X International symposium on Respiratory Viral infections, Singapore, Sunday 2nd March 2008 (7) Writing Committee of the Second World Health Organization Consultation on Clinical Aspects of Human Infection with Avian Influenza A (H5N1) Virus. Update on Avian Influenza A (H5N1) Virus Infection in Humans. N Engl J Med 358;3 (8) de Jong MD, Thanh TT, Khanh TH, et al. Oseltamivir resistance during treatment of influenza A (H5N1) infection. N Engl J Med 2005;353:2667-72 (9) Saad MD, Boynton BR, Earhart KC, et al. Detection of oseltamivir resistance mutation N294S in humans with influenza A H5N1. In: Program and abstracts of the Options for the Control of Influenza Conference, Toronto, June 17-23, 2007:228. abstract. (10) Hurt AC. et al. Susceptibility of highly pathogenic (H5N1) avian influenza viruses to the neuraminidase inhibitors and adamantanes. Antiviral Research 73 (2007) 228-231 (11) World Health Organization. Influenza A (H1N1) virus resistance to oseltamivir - Last quarter 2007 to 28 February 2008. 28 February 2008. http://www.who.int/csr/disease/influenza/H1N1ResistanceWeb20080228.pdf (12) World Health Organization. WHO/ECDC frequently asked questions for Oseltamivir Resistance. Last updated 15 February 2008.</PRE>
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MISSISSAUGA, ON, March 4 /CNW/ - Physicians from countries affected bythe deadly H5N1 influenza virus (bird or avian flu) have presented casereports about antiviral use in patients infected with H5N1, includingtreatment with the oral antiviral TAMIFLU(R) (oseltamivir). The physicians'reports were revealed this week at the International Symposium on RespiratoryViral Infections (ISRVI) in Singapore.(1)</PRE>
TAMIFLU is approved for both the treatment and post-exposure prevention(prophylaxis) of influenza in adults and in children one year and older.Studies supporting the approval of TAMIFLU are based in seasonal influenza.The magnitude of effect of TAMIFLU in treating and preventing novel strains ofinfluenza (such as those that may be involved in a pandemic or associated withavian flu) cannot be predicted as it has not been studied or approved in apandemic scenario. The World Health Organization (WHO) has recommended thathigher doses and longer treatment durations may be required to combat novelstrains of influenza.</PRE>
According to the WHO, the H5N1 virus has already killed 234 people in 12countries.(2) In the most recent clinical management guidelines issued by theWHO, TAMIFLU remains the primary antiviral agent of choice for the treatmentof H5N1 virus infections.(3) Symposium findings In Indonesia, of the total of 119 H5N1 human cases reported, 22 survived- an 18 per cent survival rate overall. Of the 119, 33 patients received noTAMIFLU, all of whom died. TAMIFLU was administered to the other 86 patients,with a 26 per cent survival rate overall. Time from onset of illness toinitiation of treatment appeared to influence survival. Of the two patientswho received TAMIFLU within 24 hours of illness onset, both survived. If giventhe drug within four days, 55 per cent survived (6/11), and 35 per centsurvived if given TAMIFLU within six days (13/37).(4) The survival rate ofthose receiving it later than six days after illness onset was 18 per cent(9/49).(2)</PRE>
Recent information about eight Vietnamese patients infected with H5N1 wasalso presented. All eight patients received TAMIFLU, however, all eightpatients presented to the hospital later than five days after onset ofillness. Only three of the eight patients survived reinforcing that treatmentbenefit is reduced for patients that receive the drug later in the course ofillness.(4),(5) In two patients who were unable to take the drug orally due tothe severity of their illness, physicians administered the drug by nasogastrictube and found it was well absorbed and there was a reduction in H5N1 virus inthese patients. Susceptibility of circulating H5N1 strains to TAMIFLU These clinical findings are supported by animal data, also presented atISRVI, which shows that oseltamivir treatment was effective against H5N1influenza viruses representing different clades/subclades. However, higherdoses were required for the more pathogenic H5N1 viruses.(6)</PRE>
"Multiple factors can affect the susceptibility of antiviral therapy withhighly pathogenic H5N1 influenza viruses and it is reassuring thatoseltamivir, in mouse models, demonstrates activity even to the mostpathogenic circulating strains," comments study author Dr. Elena Govorkova,St. Jude Children's Research Hospital, Memphis, US. "Antiviral drugs are anessential component for the early control of an influenza pandemic."</PRE>
Data also confirms the low level of resistance reported to-date withTAMIFLU to H5N1 avian influenza in the field; there are only five cases ofpublished reports of H5N1 resistance or reduced susceptibility to TAMIFLU todate.(7),(8),(9) Laboratory results have shown 96 per cent of H5N1 strains (53out of 55) tested in the laboratory were sensitive to TAMIFLU.(10)</PRE>
This compares to the around 14 per cent of isolates tested this year ofthe seasonal influenza A H1N1 virus showing resistance to TAMIFLU, reported atthe conference.(11) It is important to note that these increased levels ofresistance have only been reported spontaneously in this year's H1N1 (SolomonIslands) seasonal strain, and not an avian strain such as H5N1, and not inpatients who have been administered TAMIFLU.(12)</PRE>
"Currently, we are seeing that TAMIFLU has been used as part of theclinical management of patients infected with H5N1 with only isolated cases ofresistance being reported," comments Dr. David Reddy, Global Pandemic TaskForce Leader at Roche. "This is reassuring for governments that havestockpiled TAMIFLU for pandemic use. It is, however, critical that both Rocheand the medical community remain vigilant so that we can understand thismutating virus and be best prepared for defence against a potential pandemicstrain."</PRE>
Roche has undertaken several research initiatives to study the use ofTAMIFLU against the evolving H5N1 avian influenza virus, includingcollaborations with the National Institutes of Health (NIH), the SoutheastAsia Influenza Clinical Trials Research Network, and other researchinstitutions. Note to editors: Difference between a pandemic strain of influenza and seasonal influenza A pandemic strain of influenza is always of the A variety and is acompletely new strain to which there will be no immunity. A seasonal strain ofinfluenza is one that has previously been circulating, which may have changedslightly (antigenic drift) and to which a level of immunity exists. About pandemic influenza An influenza pandemic occurs when a new strain of influenza A virusappears, against which the human population has no immunity resulting inseveral, simultaneous epidemics worldwide with enormous numbers of deaths andillness. The most severe influenza pandemics to date include: 'Spanish flu' A(H1N1): 1918 caused in excess of 30 million deaths worldwide; 'Asian flu' A(H2N2): 1958 caused one million deaths worldwide; 'Hong Kong flu' A (H3N2):1968 caused 800,000 deaths worldwide in six weeks. The WHO believes that weare as close to the next pandemic as we have been at any time in the past 37years, with two of the three widely-recognized prerequisites for a humanpandemic met to date in the avian influenza outbreak in East Asia. Firstly, anew influenza virus strain has emerged (H5N1), and secondly, the virus hasspread to humans. The final barrier will be the effective transmission of thevirus from human to human. About TAMIFLU TAMIFLU is designed to be active against all clinically relevantinfluenza viruses and works by blocking the action of the neuraminidase (NA)enzyme on the surface of the virus. When neuraminidase is inhibited, thespread of the virus to other cells in the body is inhibited. It is licensedfor the treatment and prophylaxis of influenza in children aged one year andabove and in adults. The most frequently reported adverse events in clinicalstudies were nausea, vomiting, and diarrhea. TAMIFLU is available for thetreatment of influenza in more than 80 countries worldwide.</PRE>
TAMIFLU was approved based on studies in seasonal influenza. Themagnitude of effect of TAMIFLU in treating and preventing novel strains ofinfluenza (such as those that may be involved in a pandemic or associated withavian flu) cannot be predicted. The WHO has recommended that higher doses andlonger duration may be required. Roche and Gilead TAMIFLU was invented by Gilead Sciences and licensed to Roche in 1996.Roche and Gilead partnered on clinical development, with Roche leading effortsto produce, register and bring the product to the markets. Under the terms ofthe companies' agreement, amended in November 2005, Gilead participates withRoche in the consideration of sub-licenses for the pandemic supply of TAMIFLUin resource-limited countries. To ensure broader access to TAMIFLU for allpatients in need, Gilead has agreed to waive its right to full royaltypayments for product sold under these sub-licenses. About Roche Headquartered in Basel, Switzerland, Roche is one of the world's leadingresearch-focused healthcare groups in the fields of pharmaceuticals anddiagnostics. As the world's biggest biotech company and an innovator ofproducts and services for the early detection, prevention, diagnosis andtreatment of diseases, the Group contributes on a broad range of fronts toimproving people's health and quality of life. Roche is the world leader inin-vitro diagnostics and drugs for cancer and transplantation, a market leaderin virology and active in other major therapeutic areas such as autoimmunediseases, inflammation, metabolism and central nervous system. << Additional information - Roche Health Kiosk, Influenza: www.health-kiosk.ch/start_grip.htm - About TAMIFLU: www.roche.com/med_mbTAMIFLU05e.pdf - About influenza: www.roche.com/med_mbinfluenza05e.pdf - WHO: Global influenza programme: www.who.int/csr/disease/influenza/en/ - WHO: Avian flu: www.who.int/mediacentre/factsheets/avian_influenza/en/ References (1) Antivirals and therapeutics session, X International symposium on Respiratory Viral infections, Singapore, Sunday 2nd March 2008 (2) World Health Organization. Cumulative Number of Confirmed Human Cases of Avian Influenza A/(H5N1) Reported to WHO. 28 February 2008 http://www.who.int/csr/disease/avian_influenza/country/cases_table_2008_02_28/en/index.html (3) http://www.who.int/csr/disease/avian_influenza/guidelines/ClinicalManagement07.pdf (4) Sedyaningsih ER. The Indonesian Experience, X International symposium on Respiratory Viral infections, Singapore, Sunday 2nd March 2008 (5) Wertheim HFI. The recent Vietnamese Experience, X International symposium on Respiratory Viral infections, Singapore, Sunday 2nd March 2008 (6) Govorkova E. Influenza Antivirals in H5N1 Disease, Animal Model, X International symposium on Respiratory Viral infections, Singapore, Sunday 2nd March 2008 (7) Writing Committee of the Second World Health Organization Consultation on Clinical Aspects of Human Infection with Avian Influenza A (H5N1) Virus. Update on Avian Influenza A (H5N1) Virus Infection in Humans. N Engl J Med 358;3 (8) de Jong MD, Thanh TT, Khanh TH, et al. Oseltamivir resistance during treatment of influenza A (H5N1) infection. N Engl J Med 2005;353:2667-72 (9) Saad MD, Boynton BR, Earhart KC, et al. Detection of oseltamivir resistance mutation N294S in humans with influenza A H5N1. In: Program and abstracts of the Options for the Control of Influenza Conference, Toronto, June 17-23, 2007:228. abstract. (10) Hurt AC. et al. Susceptibility of highly pathogenic (H5N1) avian influenza viruses to the neuraminidase inhibitors and adamantanes. Antiviral Research 73 (2007) 228-231 (11) World Health Organization. Influenza A (H1N1) virus resistance to oseltamivir - Last quarter 2007 to 28 February 2008. 28 February 2008. http://www.who.int/csr/disease/influenza/H1N1ResistanceWeb20080228.pdf (12) World Health Organization. WHO/ECDC frequently asked questions for Oseltamivir Resistance. Last updated 15 February 2008.</PRE>