Tamiflu can save bird-flu patients
Physicians from countries worst affected by the deadly bird-flu virus have reported an increased survival rate in patients treated with the oral antiviral oseltamivir (Tamiflu), reinforcing the World Health Organization (WHO) advisory that Tamiflu is the only antiviral strongly recommended for the treatment of humans infected with the H5N1 virus. The physicians' reports were revealed at the International Symposium on Respiratory Viral Infections (ISRVI) in Singapore in March. According to the WHO, the H5N1 virus has already killed 234 people in 12 countries. Tamiflu is the only antiviral reported to have been used against H5N1 in humans outside the laboratory and actually in the field. In Indonesia, of the total 119 H5N1 human cases reported, 22 survived-an 18-percent survival rate overall. Of these, 33 patients received no Tamiflu, all of whom died. Tamiflu was administered to 86 patients with a 26-percent survival rate overall. Time from onset of illness to initiation of treatment appeared to influence survival. Of the two patients who received Tamiflu within 24 hours of illness onset both survived. Fifty-five percent survived if given the drug within four days (6/11), and 35 percent survived if given Tamiflu within six days (13/37). The survival rate of those receiving it later than six days after illness onset was 18 percent (9/49). Recent information on eight Vietnamese patients who received Tamiflu was also presented. However, all 8 patients presented to the hospital later than five days after onset of illness. Only three survived, reinforcing that treatment benefit is reduced for patients that receive the drug later in the course of illness. In two patients who were unable to take the drug orally due to the severity of their illness physicians administered the drug by nasogastric tube and found it was well absorbed and there was a reduction in H5N1 virus in these patients. These clinical findings are supported by new animal data, also presented at ISRVI, which show that oseltamivir treatment was effective against H5N1 influenza viruses representing different clades and subclades. However, higher doses were required for the more pathogenic H5N1 viruses. "Multiple factors can affect the susceptibility to antiviral therapy of highly pathogenic H5N1 influenza viruses and it is reassuring that oseltamivir, in mouse models, demonstrates activity even to the most pathogenic circulating strains," commented author Dr. Elena Govorkova of St. Jude Children's Research Hospital in Memphis. "Antiviral drugs are an essential component for the early control of an influenza pandemic." Data also confirm the low level of H5N1 resistance to Tamiflu reported to date. Only five cases have been reported to date while laboratory results have shown 96 percent of H5N1 strains (53 out of 55) tested in the laboratory were sensitive to Tamiflu. M
BASEL, Switzerland The European Commission has approved Roche's oral chemotherapy capecitabine (Xeloda) for the treatment of metastatic colorectal cancer in combination with any chemotherapy in all lines of treatment with or without bevacizumab. The broad approval means that more patients suffering from colorectal cancer that has spread will now be able to take advantage of effective and innovative treatments with proven patient benefits. The approval was based on pivotal studies showing that capecitabine tablets offer patients a more flexible treatment option with less hospitalization but with the same survival benefits and safety as the previous standard chemotherapy intravenous 5-fluorouracil (5-FU), and that bevacizumab in combination with chemotherapy allows patients to live significantly longer without their cancer progressing. "Colorectal cancer is a devastating disease and treatment options for patients have been limited," said Prof. Jim Cassidy, Cancer Research UK professor of oncology and chair of medical oncology at Beatson Oncology Center, University of Glasgow, Scotland. He added: "Until now, capecitabine has been available to only a few colorectal-cancer patients. But several studies have now shown that almost all patients with colorectal cancer that has spread can benefit from capecitabine at any time and in combination with any chemotherapy treatment. It is a highly effective oral chemotherapy that reduces hospital treatment time by 160 hours compared to the old standard chemotherapy, allowing patients to live as normal a life as possible. This approval shows that the EU authorities have endorsed that oral capecitabine can replace intravenous 5-FU in all colorectal cancer regimens, making cancer treatment regimens easier for patients." M
BASEL, Switzerland Roche announced that Genentech has received accelerated approval from the United States Food and Drug Administration (FDA) for bevacizumab (Avastin) in combination with paclitaxel chemotherapy for the first-line treatment of patients with locally recurrent or metastatic breast cancer. The approval is based on a phase-III study (E2100) which showed that for patients with metastatic breast cancer, the addition of Avastin to paclitaxel compared with paclitaxel alone doubled the chance of being alive without the disease advancing (progression-free survival or PFS). In Europe Avastin received full approval for the treatment of metastatic breast cancer in March 2007. The E2100 trial was sponsored by the US National Cancer Institute under a cooperative research and development agreement and was conducted by a network of researchers led by the Eastern Cooperative Oncology Group (ECOG). E2100 was a multicenter, randomized, controlled clinical trial that enrolled 772 patients with previously untreated, locally recurrent, or metastatic breast cancer. Patients were randomized to receive weekly treatment with paclitaxel every three out of four weeks with or without Avastin. Based on an independent, blinded review of patient scans, patients treated with Avastin plus paclitaxel experienced a 52-percent reduction in the risk of disease progression or death compared with those treated with paclitaxel alone (based on a hazard ratio of 0.48; p <0.0001). In the Avastin arm, median PFS was 11.3 months versus 5.8 months in the paclitaxel arm. Based on the investigator assessment, patients treated with Avastin plus paclitaxel experienced a 58-percent reduction in the risk of disease progression or death compared with those treated with paclitaxel alone (based on a hazard ratio of 0.42; p <0.0001). Overall survival was also longer in the Avastin group although the difference failed to reach statistical significance (p = 0.14). A one-year exploratory analysis of overall survival was significantly improved with the addition of Avastin (73.8 percent vs. 82.3 percent; p = 0.007). Safety findings were generally consistent with those in previous trials of Avastin plus chemotherapy and no new safety signals related to Avastin were observed. "This is excellent news representing a significant advancement in breast-cancer therapy." said Dr. David Miles, medical oncologist at Mount Vernon Hospital, United Kingdom. "The decision confirms the importance of progression-free survival as a clinically meaningful benefit to patients. Avastin effectively doubles the time patients live without their disease advancing, which is highly significant for our patients and their families." "[The] decision represents a major milestone for patients and oncologists in the US" said William Burns, chief executive for Roche Pharmaceuticals. "The FDA has recognized that Avastin is a breakthrough drug which is now approved in Europe and the US for the three cancers with the highest death toll-breast, lung, and colorectal cancer." Globally, breast cancer is the second most common form of cancer and the second leading cancer killer of women with an estimated annual death toll in excess of 400,000. M
BASEL, Switzerland Results of a large-scale study of patients with chronic kidney disease (CKD) who are not on dialysis and who have never received a treatment for anemia, found that CERA (continuous erythropoeitin receptor activator) given at an extended dosing interval once every two weeks effectively corrects anemia. The authors of the ARCTOS (Administration of CERA in CKD patients to treat anemia with a twice-monthly schedule) study published in the Clinical Journal of the American Society of Nephrology, say CERA provides a smooth and steady increase in hemoglobin levels in accordance with current guidelines. In the study, patients who received CERA every two weeks achieved a 97.5-percent response, compared with those who received darbepoetin alfa weekly who achieved a hemoglobin response of 96.3 percent. The study lasted for 28 weeks. The study found that significantly fewer patients on CERA experienced a hemoglobin value exceeding the upper ceiling of 13 g/dL set for the trial during the first eight weeks, 12.4 percent versus 33.5 percent of patients taking darbepoetin alfa. Indeed, for the whole study it was significant that 67.7 percent of patients taking CERA and 80.6 percent of patients taking darbepoetin alfa experienced at least one hemoglobin value greater than 13 g/dL. In addition, the study found that fewer patients treated with CERA (2.5 percent) required one or more blood transfusions during the correction and evaluation periods compared with darbepoetin alfa (6.8 percent). "Safety is of paramount importance in this population of patients who are often quite ill despite the fact that they have not yet progressed to dialysis. We were pleased to see that the most adverse events were mild to moderate, and few were considered treatment-related," said lead investigator Dr. Iain Macdougall of King's College Hospital, London. He noted that patients were on average in their early to mid-60s, male, and suffering from illnesses such as diabetes, high blood pressure, or heart disease. "Although patients in clinical trials are often quite different from those in an unselected renal-unit population, there is no reason to suggest that similar efficacy and safety results would not be expected with CERA in routine clinical practice," Macdougall added. CERA has been approved in the European Union, United States, and Switzerland to provide correction of anemia with once-every-two-weeks dosing and maintenance of stable hemoglobin levels with once-monthly use in all CKD patient types. It has a different receptor interaction and longer half-life which allows for sustained and predictable anemia management. M |
