An interferon beta polypeptide comprising interferon-beta 1a coupled to a
polymer containing a polyalkylene glycol moiety wherein the
interferon-beta-1a and the polyalkylene glycol moiety are arranged such
that the interferon-beta-1a has an enhanced activity relative to another
therapeutic form of interferon beta (interferon-beta-1b) and exhibits no
decrease in activity as compared to non-conjugated interferon-beta-1a.
The conjugates of the invention are usefully employed in therapeutic as
well as non-therapeutic, e.g., diagnostic, applications.