1.   Avonex and Betaseron are both genetically engineered copies of beta interferon, a naturally occurring immune-system hormone.

2.   Biogen markets a form of beta interferon as its Avonex drug for multiple sclerosis.

3.   Biogen, based in Cambridge, Mass., said it would seek federal and European regulatory approval for beta interferon early next year.

4.   Biogen Corp. came a step closer Monday to getting its drug beta interferon to market when it formally filed a new drug application for Food and Drug Administration approval.

5.   Biogen hopes to apply early next year for Food and Drug Administration approval of beta interferon, and analysts said the FDA would probably move quickly.

6.   Both are forms of beta interferon, an artificial version of a natural substance made by the immune system.

7.   Jacobs, who helped direct the Biogen study, said that it was not possible to say which form of beta interferon was better.

8.   Monnday is reality-check time for Biogen, which will release the data from trials of its genetically engineered beta interferon in slowing the effects of multiple sclerosis.

9.   Now Biogen has announced that its drug, also a genetically engineered form of beta interferon, has been found to be effective.

10.   Robbins, however, is responding favorably to treatment with the drug beta interferon, which he injects into his system every other day.