ASH 2018: Is Urine Immunofixation Necessary to Define Complete Remission in Myeloma
Posted: Friday, December 14, 2018
A subanalysis of the GEM2012MENOS65 phase III trial suggests that urine immunofixation may be an unnecessary additional measurement to determine complete remission in patients being treated for multiple myeloma. Bruno Paiva, PhD, of the Clinica Universidad De Navarra, Pamplona, Navarra, Spain, and colleagues found similar clinical responses among patients classified as in “complete remission,” with both negative serum and urine immunofixation, and those lacking a urine immunofixation test. These results, presented at the 2018 American Society of Hematology (ASH) Annual Meeting & Exposition in San Diego (Abstract 474), discourage the application of the First Trial Independent Response Adjudication Committee conversion criteria.
The investigators performed more than 3,700 protein evolution studies, and 453 patients with multiple myeloma were evaluated. The M component was detected exclusively in serum (n = 173) or in both serum and urine (n = 212). Patient responses were classified as very good partial response, uncertain complete response, or complete response.
A negative serum immunofixation at diagnosis predicted a negative urine immunofixation test in 97.2% of patients. In addition, minimal residual disease rates did not significantly differ between the complete response group and the uncertain complete response group (P = .1). However, progression-free survival values and minimal residual disease rates in the complete response and uncertain complete response groups were significantly superior to those in the very good partial response group.
“Our results suggest that, except for those with pure [Bence-Jones M protein], patients fulfilling [complete response] criteria but with unavailable urine [immunofixation] should be classified as [complete response] instead of [very good partial response],” the study authors concluded.