Analysis of Four Large Post-Marketing Surveillance Studies Describe Clinical Effects of Sucrose-Formulated Recombinant Factor VIII
Data Describing Prophylactic Treatment in Adults with Hemophilia A also Presented
BOSTON, July 13 /PRNewswire/ -- New data pooled from four large, "real world" post-marketing surveillance studies showed that sucrose-formulated recombinant factor VIII (rFVIII-FS) reduced bleeding and provided data regarding adverse events in more than 950 patients with mild-to-severe hemophilia A. Additionally, rates of inhibitor formation were reported in both previously treated and previously untreated patients. The data were presented at the XXII Congress of the International Society on Thrombosis and Haemostasis (ISTH).(1)(2)
In this analysis, the investigators judged rFVIII-FS hemostasis to be "good" or "very good" in 98.9 percent of patients. Serious adverse drug reactions were seen in 1.1 percent of patients and new (de novo) inhibitors were observed in 0.8 percent of patients.
"In a 'real world' setting, these data reflect some of the extensive global clinical experience with rFVIII-FS," said Georg Lemm, M.D., Ph.D., vice president, Global Clinical Development, and head, Hematology Group, Bayer Schering Pharma. "It is particularly noteworthy that a low rate of inhibitor formation was observed in this analysis of data pooled from post-marketing surveillance studies. Inhibitor formation is a significant challenge for both clinicians and their patients, and its treatment is costly and requires significant time to overcome."
Open label study investigating the efficacy of prophylactic versus on-demand rFVIII-FS treatment
In another presentation, (3) data from an open label clinical study that enrolled 20 adult men with severe hemophilia A (with and without target joints) demonstrated that patients who were changed from on-demand to prophylactic (preventive) infusions of rFVIII-FS had significantly reduced median joint bleeds per 6-month treatment period (zero events versus 15.0 events, respectively; P<0.001) and improved median total Gilbert Scores (18 versus 25, respectively; P<0.001) compared with on-demand treatment.
Fifty-one adverse drug events reported; of them, 94 percent were mild or moderate, and did not lead to study withdrawal. Six serious adverse drug reactions did occur, none of which were considered treatment related by the investigators.
Poster no. PP-MO-577: Post-marketing experience with sucrose-formulated recombinant factor VIII in patients with hemophilia A.
Pooled results from four open-label, post-marketing studies were reported by Katsuyuki Fukutake, M.D., Tokyo Medical University Hospital, Tokyo, Japan. The investigators judged hemostasis to be "very good" or "good" in 98.9 percent of 953 patients and patient acceptance was rated as "good" or "very good" for 97.4 percent of patients. Treatment-related adverse drug events were observed in 13 of 967 patients (1 percent), while only 11 patients (1.1 percent) experienced serious adverse drug reactions, including inhibitor formation, hemarthrosis and catheter placement complications. Tolerability was judged by the investigators to be "very good" or "good" in 99 percent of patients.
One or two infusions were required to treat bleeds in 87.5 percent of patients who used rFVIII-FS for on demand bleeding. For prophylaxis, one or two infusions were used by 76.4 percent of patients. In addition, rFVIII-FS was effective in controlling bleeding during surgical procedures, with hemostasis judged as "excellent" or "good" in 93.4 percent of 61 procedures.
Poster no. PP-WE-579: Inhibitor formation with sucrose-formulated recombinant factor VIII in patients with hemophilia A: Results from post-marketing surveillance studies.
Dr. Fukutake also reported pooled results evaluating inhibitor formation following rFVIII-FS treatment from the same four open-label studies. The study assessed de novo, recurrent and ongoing inhibitor formation in 967 patients across the four studies. Nearly 95 percent of patients had received prior treatment, 76 (7.9 percent) of whom had a history of inhibitors.
Fourteen of the 967 patients evaluated (1.4 percent) experienced a positive inhibitor test during the study period. De novo inhibitors were detected in seven of 891 patients (0.8 percent; mean treatment duration 90 +/-50 days [mean+/-SD]) and recurrent or ongoing inhibitors were found in 7 of 76 patients with a positive inhibitor history (mean treatment duration 76.9+/-123.2 days). One patient of 51 previously untreated patients developed inhibitors and of the 348 patients who reported prior treatment with plasma-derived FVIII, none developed inhibitors upon switching to rFVIII-FS.
Poster no. PP-TH-584: Efficacy of secondary prophylactic versus on-demand sucrose-formulated recombinant factor VIII treatment in adults with severe hemophilia A with and without target joints.
The results of a Bayer-sponsored, open-label clinical trial were reported by lead investigator Peter Collins, M.D., centre director, Arthur Bloom Haemophilia Centre at the University Hospital of Wales, Cardiff, United Kingdom. The aim of the study was to evaluate the effect of prophylactic treatment on the number of joint bleeds in adult men with severe hemophilia A compared with on-demand treatment in a single-arm cross-over treatment trial. During the first six months of the study, all patients received on-demand rFVIII-FS treatment. Patient therapy was then changed to a prophylactic treatment regimen for seven months.
In this study, which enrolled 20 adult men, results showed the median number of joint bleeds per patient per 6-month treatment period was significantly lower during the prophylaxis period (0 events [range 0-3]) compared with the on-demand period (15.0 events [range 11-26]; P<0.001 median total Gilbert scores (a measure of joint function, lower scores demonstrating improvement) were 18.0 (range 3-29) at the end of prophylaxis versus 25.0 (range 4-46) following on-demand treatment (P<0.001). No differences were noted in quality of life or health economic parameters, and no inhibitor formation was observed during the study. Fifty-one adverse drug events were reported in 13 patients (65 percent): 26 during on-demand therapy and 25 during prophylaxis. Ninety-four percent of these were mild or moderate, and did not lead to study withdrawal. Six serious adverse drug reactions occurred in two patients (one in each period), none of which were considered treatment related by the investigators.
About Hemophilia A
Hemophilia A, also known as factor VIII deficiency or classic hemophilia, is largely an inherited bleeding disorder in which one of the proteins needed to form blood clots in the body is missing or reduced. Hemophilia A is the most common type of hemophilia and is characterized by prolonged or spontaneous bleeding, especially into the muscles, joints, or internal organs. Approximately 400,000 people around the world have hemophilia A.
About Bayer HealthCare Pharmaceuticals Inc.
Bayer HealthCare Pharmaceuticals Inc. is the U.S.-based pharmaceuticals unit of Bayer HealthCare LLC, a subsidiary of Bayer Corporation. One of the world's leading, innovative companies in the healthcare and medical products industry, Bayer HealthCare combines the global activities of the Animal Health, Consumer Care, Diabetes Care, and Pharmaceuticals divisions. In the U.S., Bayer HealthCare Pharmaceuticals comprises the following business units: Diagnostic Imaging, General Medicine, Specialty Medicine and Women's Healthcare. The company's aim is to provide products that will improve human health worldwide by diagnosing, preventing and treating diseases.
This news release contains forward-looking statements based on current assumptions and forecasts made by Bayer Group management. Various known and unknown risks, uncertainties and other factors could lead to material differences between the actual future results, financial situation, development or performance of the company and the estimates given here. These factors include those discussed in our annual and interim reports filed with the Frankfurt Stock Exchange. The company assumes no liability whatsoever to update these forward-looking statements or to conform them to future events or developments.
(1) Fukutake K, et al. Post-marketing experience with sucrose-formulated recombinant factor VIII in patients with hemophilia A. Poster no. PP-MO-577; XXII Congress of the International Society on Thrombosis and Haemostasis.
(2) Fukutake K, et al. Inhibitor formation with sucrose-formulated recombinant factor VIII in patients with hemophilia A: Results from post-marketing surveillance studies. Poster no. PP-WE-579; XXII Congress of the International Society on Thrombosis and Haemostasis.
(3) Collins P, et al. Efficacy of secondary prophylactic versus on-demand sucrose-formulated recombinant factor VIII treatment in adults with severe hemophilia A with and without target joints. Poster no. PP-TH-584; XXII Congress of the International Society on Thrombosis and Haemostasis.
Source: Bayer HealthCare
CONTACT: Sreejit Mohan of Bayer HealthCare, +1-510-705-5477
Posted: July 2009