I found it especially misleading that they used anecdotal evidence to claim that the cheaper drug is equivalent in function and safety.
That said, Genentech is on the wrong side of the PR angle here and unfortunately for them, some internal documents got exposed which make them seem less than angelic here. If the cost differential of producing the drugs really is small, then they don't have a strong position, because it makes them appear as if they are using one of the drugs as a profit center to fund future R&D.
Anyway, the article really glosses over stuff, but you'd need to spend about 5-7 years getting a PhD in pharmaceutical chemistry, plus working in industry for a few years before you understand the business and science of what genentech does.