I've not done the methotrexate in combo with a biologic due to past adverse reactions to methotrexate alone, but don't be dissuaded by the experience of others, as we all react differently to different medications. Methotrexate is often prescribed as an add on treatment, but in lower dosage than when it's a stand alone, because it is thought that doing so can hold off the body's development of anti drug antibodies (immunogenicity)for a far greater time. But honestly, if the drug isn't working all that well any more, then you may have already begun developing immunogenicity, and changing to a different drug might be more helpful.