Which companies manufacture the drug extavia?

Who makes Extavia (interferon beta-1b)?

Extavia is manufactured by Novartis. [1]

Are there other companies that make a version of Extavia?

The information provided identifies Extavia as being made by Novartis, but it does not name any additional manufacturers or partners for other versions. [1]

What should I look for on the label or packaging?

For Extavia, the manufacturer name is expected to appear on the product labeling in line with Novartis being the company that manufactures it. [1]

Sources

1. https://www.drugs.com/extavia.html