Influenza patients treated with Tamiflu has higher survival rates

Sep 14 2009

Roche (SIX: RO, ROG; OTCQX: RHHBY) announced today that two new observational studies concluded that influenza patients treated with Tamiflu(R) (oseltamivir phosphate) had significantly higher survival rates than untreated patients. The studies, examining nearly 1,000 people, analyzed outcomes for two different groups -adults and children diagnosed with the highly pathogenic A (H5N1) avian influenza and adults hospitalized with seasonal influenza. Results, which build on similar findings, were presented today at the 49th ICAAC annual meeting in San Francisco.

"These retrospective studies support the potential benefits of antiviral treatment in severe cases of influenza," said Dominick Iacuzio, Ph.D., medical director at Roche, which manufactures Tamiflu. "While Tamiflu is approved and used in many countries to treat and prevent all types of A and B influenza, these 'real-world' studies contribute to the body of clinical evidence."

Study Summaries

First Results from an Avian Influenza Case Registry (Presentation V-533) -- Sunday, September 13, 2009, 9:00 a.m. - 9:30 a.m. PT, Marriott Salon 9.

The study examined outcomes data for 215 patients from 10 countries who were diagnosed with the virulent A (H5N1) avian influenza. The retrospective observational study found that untreated patients had a mortality rate of 88%, with 11 out of 89 (12%) untreated patients surviving, in contrast to survival of 45 out of 85 (53%) patients who received at least one dose of Tamiflu up to 8 days after symptom onset. Among a subset of patients who received Tamiflu within 2 days of symptom onset, 5 out of 7 patients (71%) survived.

The study was conducted by researchers from Avex Avian Influenza Expert Group and the London School of Hygiene and Tropical Medicine, in collaboration with Roche. It is the first to systematically assess human A (H5N1) infection in multinational cases. Data were collected in-country and supplemented with data abstracted from published cases. Data were anonymized and reviewed for accuracy. Nearly all cases were confirmed at laboratories accredited by the World Health Organization (WHO).

"These data confirm the importance of prompt diagnosis and treatment with Tamiflu. They also support previous studies indicating that treatment may still beneficial even after 48 hours," explained Dr. Iacuzio.

The A (H5N1) avian influenza virus continues to spread throughout parts of Southeast Asia, Africa and the Middle East. Since 2003, the WHO has reported 440 human cases of A (H5N1), 262 of them fatal. Most recently, two new human cases were reported in Egypt on August 31, 2009 (www.who.int/csr/disease/avian_influenza/en/)

Outcomes of Adults Hospitalized with Influenza, 2007 - 2008 (Poster 577) - Sunday, September 13, 2009, 11:15 a.m. - 1:15 p.m. PT, Hall B.

The study analyzed 760 patients hospitalized with severe seasonal influenza, half of whom received Tamiflu>

The retrospective, observational study was conducted in two general hospitals in Hong Kong during a 24-month period, studying patients over the age of 18 who were hospitalized with confirmed influenza. Most patients were older (average age 70), 60% had underlying chronic illness, and 78% were hospitalized with influenza complications.

The CDC recently issued updated interim recommendations for the use of antiviral medications in the treatment and prevention of influenza for the 2009-2010 season (http://flu.gov/vaccine/antiviralguidance.pdf). The guidance covers seasonal influenza as well as the pandemic A (H1N1) virus.

Additional Data Presentations from Roche on Tamiflu in Influenza Management

• High-Dose Oseltamivir Regimens Well-Tolerated by Healthy Adults (Poster 554) - Sunday, September 13, 2009, 11:15 a.m. - 1:15 p.m. PT, Hall B.
• Effect of Oseltamivir on Anticoagulation: A Crossover Study in Patients Stabilized on Warfarin (Poster 50) - Sunday, September 13, 2009, 11:15 a.m. - 1:15 p.m., Hall B.
• Emergence and Evolution of Influenza A (H1N1) Viruses with H274Y and Associated Mutations (Poster 561) - Sunday, September 13, 2009, 11:15 a.m. - 1:15 p.m., Hall B.