I think Jak inhibitors also reduce IL-6 levels. IL-6 is the cytokine which is implicated the most for PMR and GCA. With a Jak inhibitor you might reduce both IL-6 and Jak inflammation pathways

There aren’t single inflammation pathways independent of others. It is a complicated network of inflammatory processes with many actions and reactions taking place instantly in real time. A single dose of prednisone or any medication can’t replicate what the body does.