In this JCO Article Insights episode, host Michael Hughes summarizes "Co-Occurrence of Cytogenetic Abnormalities and High-Risk Disease in Newly Diagnosed and Relapsed/Refractory Multiple Myeloma" by Kaiser et al, published February 18, 2025, followed by an interview with JCO Associate Editor Suzanne Lentzsch.

Transcript

Michael Hughes: Welcome to this episode of JCO Article Insights. This is Michael Hughes, JCO's editorial fellow. Today I have the privilege and pleasure of interviewing Dr. Suzanne Lentzsch on the “Co-Occurrence of Cytogenetic Abnormalities and High-Risk Disease in Newly Diagnosed and Relapsed/Refractory Multiple Myeloma” by Dr. Kaiser and colleagues.

At the time of this recording, our guest has disclosures that will be linked in the transcript.

The urge to identify patients with aggressive disease, which is the first step in any effort to provide personalized medical care, is intuitive to physicians today. Multiple myeloma patients have experienced heterogeneous outcomes since we first started characterizing the disease. Some patients live for decades after treatment. Some, irrespective of treatment administered, exhibit rapidly relapsing disease. We term this ‘high-risk myeloma’.

The Durie-Salmon Risk Stratification System, introduced in 1975, was the first formal effort to identify those patients with aggressive, high-risk myeloma. However, the introduction of novel approaches in therapeutic agents—autologous stem cell transplantation with melphalan conditioning, proteasome inhibitors like bortezomib, or immunomodulatory drugs like lenalidomide—rendered the Durie-Salmon system a less precise predictor of outcomes.

The International Staging System in 2005, predicated upon the burden of disease as measured by beta-2 microglobulin and serum albumin, was the second attempt at identifying high-risk myeloma. It was eventually supplanted by the Revised International Staging System (RISS) in 2015, which incorporated novel clinical and cytogenetic markers and remains the primary way physicians think about the risk of progression or relapse in multiple myeloma.

Much attention has been focused on the canonically high-risk cytogenetic abnormalities in myeloma, typically identified by fluorescence in situ hybridization: translocation t(4;14), translocation t(14;16), translocation t(14;20), and deletion of 17p. Much attention also has been focused on the fact that intermediate-risk disease, as defined by the RISS, has been shown to be a heterogeneous subgroup in terms of survival outcomes. The RISS underwent revision in 2022 to account for such heterogeneity and has become the R2-ISS, published here in the Journal of Clinical Oncology first in 2022. Translocations t(14;16) and t(14;20) were removed, and gain or amplification of 1q was added. Such revisions to core parts of a modern risk-stratification system reflect the fact that myeloma right now is in flux, both in treatment paradigms and risk-stratification systems.

The field in recent years has undergone numerous remarkable changes, from the advent of anti-CD38 agents to the introduction of cellular and bispecific therapies, to the very technology we use to investigate genetic lesions. The major issue is that we're seeing numerous trials using different criteria for the definition of high-risk multiple myeloma. This is a burgeoning problem and speaks very much now to a critical need for an effort to consolidate all these criteria on at least cytogenetic lesions as we move into an era of response-adapted treatment strategies.

The excellent article by Kaiser and colleagues, published in the February 2024 edition of the JCO, does just that in a far-ranging meta-analysis of data from 24 prospective therapeutic trials. All 24 trials were phase II or III randomized controlled trials for newly diagnosed and relapsed/refractory multiple myeloma. The paper takes a federated analysis approach: participants provided summaries and performed prespecified uniform analyses. The high-risk cytogenetic abnormalities examined were translocation t(4;14), gain or amplification of 1q, deletion of 17p, and translocation t(14;16), if included in the original trials. All of these were collected into zero, single, or double-hit categories, not unlike the system currently present in diffuse large B-cell lymphomas. The outcomes studied were progression-free survival and overall survival, with these analyses adhering to modified ITT principles.

The authors also performed prespecified subgroup analyses in the following: transplant-eligible newly diagnosed myeloma, transplant non-ineligible newly diagnosed myeloma, and relapsed/refractory myeloma. They, in addition, described heterogeneity by the I² statistic, which, if above 50%, denotes substantial heterogeneity by the Cochrane Review Handbook, and otherwise performed sensitivity analyses and assessed bias to confirm the robustness of their results.

In terms of those results, looking at the data collected, there was an appropriate spread of anti-CD38-containing and non-containing trials. 7,724 patients were evaluable of a total 13,926 enrolled in those 24 trials: 4,106 from nine trials in transplant-eligible myeloma, 1,816 from seven trials in transplant non-ineligible myeloma, and 1,802 from eight trials in relapsed/refractory disease. ISS stage for all patients was relatively evenly spread: stage I, 34.5%; stage II, 37%; stage III, 24%. In terms of high-risk cytogenetic lesions, double-hit disease was present in 13.8% of patients, and single-hit disease was present in 37.4%.

In terms of outcomes, Kaiser and colleagues found a consistent separation in survival outcomes when the cohort was stratified by the number of high-risk cytogenetic lesions present. For PFS, the hazard ratio was for double-hit 2.28, for single-hit 1.51, without significant heterogeneity. For overall survival, the hazard ratio was for double-hit disease 2.94, single-hit disease 1.69, without significant heterogeneity except in patients with double-hit disease at 56.5%. By clinical subgroups, hazard ratios remained pretty consistent with the overall cohort analysis. In transplant-eligible newly diagnosed myeloma, the hazard ratio for progression is 2.53, overall survival 4.17. For transplant non-ineligible, 1.97 progression, 2.31 mortality. Relapsed/refractory disease progression 2.05, overall mortality 2.21, without significant heterogeneity.

Of trials which started recruitment since 2015, that is to say, since daratumumab was FDA approved and thus since an anti-CD38 agent was incorporated into these regimens, analysis revealed the same results, with double-hit myeloma still experiencing worse survival by far of the three categories analyzed. Risk of bias overall was low by advanced statistical analysis. In terms of subgroup analysis, double-hit results for transplant-eligible newly diagnosed myeloma may have been skewed by smaller study effects, where the upper bound of the estimated hazard ratio for mortality reached into the 15 to 20 range.

In conclusion, from a massive amount of data comes a very elegant way to think about the role certain cytogenetic abnormalities play in multiple myeloma. A simple number of lesions - zero, one, or at least t