a) they can and will patent it, because in the end it will be same tools "bIg pHormA" uses today for all kinds of tasks. b) they are financially and subjectively interested in developing said tools to combat cancer even if they will be cloned and sold in parallel way cheaper than original. Because - 1) it would be immensely profitable on it's own, cancer is one the most common ailments, 2) post-cancer treatments are bringing in fortunes to pharma companies, because practically any cancer survivor is then locked on some medicine for life, 3) the success story alone, putting for example the most hated person in the world on a covers of literally every magazine and newspaper with a list of honorifics, awards and titles is incredibly enticing to every sociopathic CEO, 4) and as I said, not even generics or lack of crazy long patents can stop a company from becoming gold plated. I can go buy Ozempic generic for a fraction of a cost legally in a nearest apothecary, Novo is still The richest corpo in Europe anyway.
tl;dr - there is no conspiracy. It's just just hard.
PS: correction - not generics, but variants of Ozempic. But the point still stands.