Prognosis and survival rates have improved substantially in recent years for patients with multiple myeloma; however, survival improvements do not apply equally to all subgroups, most notably high-risk subgroups.

A team of researchers conducted a retrospective cohort study of patients with newly diagnosed multiple myeloma to evaluate the prognostic performance of International Staging System (ISS), revised ISS (R-ISS), and chromosomal abnormalities (CA) to describe treatment patterns and survival outcomes. Their findings were published in Leukemia & Lymphoma.

The researchers evaluated data from the Flatiron MM Enhanced EHR (New York, New York) for their study, as the Flatiron network included data from more than 280 cancer clinics and 2 million active patients. The researchers evaluated treatment distribution (cohort 1; 1979 patients) and modified progression-free survival (mPFS) and overall survival (cohort 2; 1382 patients) from 2 study periods.


Continue Reading

Treatment distribution study period was diagnosis from January 1, 2015, through June 30, 2020, with a 6-month follow-up through December 31, 2020. Survival outcomes study period was diagnosis from January 1, 2015, through December 31, 2018, with a 2-year follow-up through December 31, 2020. The patients were divided into 3 risk categories (I, II, III) at baseline, using the ISS and R-ISS risk stratification categories, and 2 risk categories based on chromosomal abnormalities (standard risk or high risk).

They found that across both cohorts, 18%, 41%, and 37% were high-risk according to the R-ISS, ISS, and high-risk CA criteria, respectively. Triplets were the most common regimens used across all risk stratification criteria, with 60% of patients treated with these regimens.

In cohort 2, median mPFS steadily decreased as risk categorization increased: R-ISS I, 23.5 months; II, 12.1 months; and III, 8.8 months; ISS I, 16.0 months; II, 12.7 months; and III, 10.4 months; and CA standard risk, 13.1 months and high risk, 10.1 months. Overall, 2-year proportion was 0.91 months, 0.79 months, and 0.65 months in patients stratified by R-ISS I, II, and III criteria, respectively. This trend was consistent in patients stratified by ISS (0.89, 0.81, and 0.68 months, respectively), and CA risk stratification (standard risk, 0.79 months; high risk, 0.75 months) criteria.

The distinct difference in median mPFS and the proportion of 2-year overall survival observed with R-ISS demonstrates its greater discriminatory power compared with ISS or high-risk CA alone, noted the researchers. In addition, median mPFS and the proportion of 2-year overall survival were consistently lower in high-risk patients than in low-risk patients.

They also recommend all patients should be assessed thoroughly to be classified by the R-ISS criteria.

Study limitations included data limitations from using the Flatiron data. These data limitations prevented the researchers from completely ascertaining treatment that began in settings other than the outpatient clinic. The results also may not be generalizable to patients who were treated in inpatient settings in countries outside the United States.

Disclosures: Some authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.

Reference

Rahman M, Keegan A, Mateus J, Kim C. Real-world assessment of the treatment patterns and outcomes among patients with multiple myeloma across different risk stratification criteria in the United States: a retrospective cohort studyLeuk Lymphoma. Published online November 12, 2022. doi:10.1080/10428194.2022.2140283