(Adds results of European and North American studies of Betaseron in paragraphs 15, 16, 17, 18, 19)
Monday May 1, 11:28 pm Eastern Time
NEW YORK, May 1 (Reuters) - Multiple sclerosis (MS) patients benefit from higher doses of beta interferon, biotech drugmaker Ares-Serono said on Monday, citing data from a long-term clinical study of its drug Rebif.
"These data demonstrate that if patients are treated early with the high-dose interferon beta-1a therapy, Rebif, the progression of the disease can be delayed," said Mark Freedman, director of the Multiple Sclerosis Clinic at the Ottawa Hospital.
Ares-Serono released the results during a meeting of the American Academy of Neurology in San Diego.
In a study of 560 patients with relapsing-remitting multiple sclerosis, disease progression slowed more in patients receiving three injections of 44 micrograms per week -- the dosage in Rebif -- than in patients getting three injections at half that dosage of 22 micrograms per week, Ares-Serono said.
Treatment with the higher dosage in the early stage of the disease showed advantages over later treatment, Ares-Serono added.
DISEASE HITS OVER 350,000 IN U.S.
The Multiple Sclerosis Foundation said that more than 350,000 people in the United States have been diagnosed with the ailment.
Ares-Serono said the life-time risk of developing the disease among the general population is about one in 1,000.
Multiple Sclerosis damages the coating around nerve fibers, leaving behind scar-like tissue called sclerosis.
Sclerotic tissue can slow down or block the transmission of signals between nerve cells, impairing vision, mobility and coordination. The symptoms can range from very mild to debilitating in which patients require a wheelchair.
Ares-Serono said it will next compare Rebif against Biogen Inc's (NasdaqNM:BGEN - news) Avonex, a nearly identical beta interferon treatment that features a lower dose.
Ares-Serono hopes to enlist 600 patients worldwide for the new study on Rebif to show that its higher dose drug, not on the market in the United States due to Biogen's "orphan drug" rights, works differently from Avonex. Rebif is available in 50 other countries.
Orphan drug status provides for U.S. marketing exclusivity for seven years upon marketing approval, as well as tax benefits and exemptions from application fees.
STUDIES YIELD MIXED RESULTS
Biogen also planned to issue data at the San Diego conference from studies on patients with monosymptomatic multiple sclerosis.
Biogen has submitted the data to a peer-reviewed journal and plans to issue a statement on May 2, a spokesman said.
In February, Biogen halted a study of Avonex on 383 patients after finding that Avonex delayed the development of Multiple Sclerosis sufficiently to stop the trial early.
Berlex Pharmaceuticals, a unit of Schering AG (quote from Yahoo! UK & Ireland: SCHG.F), on Monday also released its findings from a North American trial of its drug Betaseron (beta interferon 1b), which suggested that patients with more advanced disease are less likely to show a measurable response to treatment with interferon beta therapy as measured by the Expanded Disability Status Scale.
However, results from a European study of the drug, also released Monday, suggested Betaseron did reduce the development of hypointense T1 lesions, also known as "black holes", in the brains of patients with secondary progressive multiple sclerosis.
The European trial found that patients who took Betaseron, already approved in the United States, showed a 45 percent reduction in the development of black holes, which disrupt the flow of nerve impulses within the brain, making it difficult for patients to perform normal daily functions.
The difference between patient groups might explain why responses in the delay of progression of disability, the primary endpoint of both studies, was significant in the European trial but not in the North American trial, the results stated.
BETASERON AND REBIF NOT COMPARABLE
Ares Serono's head of regulatory and clinical development, Hisham Samra, said Betaseron has a different safety profile than Rebif, making the drugs difficult to compare.
More than 85 percent of the patients in the Rebif study continued with the treatment for four full years, Samra said. The treatment will now continue for the rest of the patients' lives, Samra added.
The four-year study is a two year extension of a clinical study that was described in The Lancet medical journal in November 1998.
Samra said some patients developed antibodies to Rebif, resulting in less improvement than in patients whose immune systems did not resist the treatment.
Ares-Serono has also extended its clinical programme to test high-dose interferon beta-1a treatment on patients with hepatitis C, rheumatoid arthritis and Crohn's disease.
"Based on the consistent effect on progression seen in the European
SP study population and on our understanding of the disease process, it
is likely that Betaseron is effective in patients in the secondary progressive
phase of disease who continue to have an inflammatory component contributing
to progression," said Henry McFarland, chairman of the Independent Monitoring
Committee of both studies.