How do you approach treatment of rheumatoid arthritis in a patient with an active hematologic malignancy (such as leukemia or lymphoma) after methotrexate failure?

Clearly, a multidisciplinary approach is important. The first consideration is of the hematologic malignancy and preferred treatments for it; as B cell depleting agents may also help control the RA. As experience with combination biologics has only shown increased adverse events and lesser efficacy, a csDMARD may still be preferable, and leflunomide offers similar efficacy to MTX without renal toxicity. It can be used in the presence of renal failure/dialysis, with dose adjustment, and has been used successfully in renal transplant patients.

Agree, we use rituximab when possible and depending on the type of the hematologic malignancy (lymphoma); however, when patients with active hematologic malignancy are treated with chemotherapy, we find that this usually controls their RA and we hold most DMARDs. Also agree that we avoid other biologics (other than rituximab) in patients with hematologic malignancies.