Introduction: Despite advances in treatment, MM remains an incurable disease. RWD are key to improving our understanding of treatment patterns for patients with MM. This study examined the proportion of patients with MM (1) treated with an immunomodulatory drug (IMiD), a proteasome inhibitor (PI), an anti-CD38 monoclonal antibody (aCD38), or Other in first line (1L) through fourth line or greater (4L+) by calendar year; and (2) who had a change in treatment regimen at line change. Subgroup analyses were performed by cytogenetic risk status (high vs. standard), stem cell transplant (SCT) eligibility (eligible vs. ineligible), and practice type (community vs. academic).

Methods: The Flatiron Health Database was used, comprising de-identified EHR-derived data for patients treated in the Flatiron Health network. Patients were excluded if they had no record of a 1L treatment recognized as an induction regimen based on NCCN guidelines, a 1L regimen that contained an active therapy for another cancer type, 1L initiated >60 days after MM diagnosis, and <3 consecutive months of data. Treatments were classified into 15 mutually exclusive categories (inclusive of steroids): Chemotherapy, IMiD, IMiD+chemo, PI, PI+chemo, IMiD+PI, IMiD+PI+chemo, aCD38, aCD38+chemo, aCD38+IMiD, aCD38+IMiD+chemo, aCD38+PI, aCD38+PI+chemo, aCD38+IMiD+PI, and Other. Treatment use and sequencing patterns were assessed using proportions.

Results: 5890 adult patients diagnosed with MM between 1/1/2011 and 12/31/19 were included. 45% of patients were female, 60% were white, and the median age was 69 (IQR = 61-76). Nearly 90% of the cohort were from community practices. Across years and lines, the most common treatment categories were IMiD, PI, and IMiD+PI. After 2015, IMiD+ PI was the dominant category in 1-3L and IMiD was the dominant category in 4L+. After 2015 and across lines, the most common aCD38 containing treatment was aCD38+IMiD. After 2015, aCD38 treatments were used in 2-4% of 1L patients regardless of subgroup. Between 2015 and 2019, the use of aCD38 treatments in 2L increased from 1% to 20% in all, standard risk, SCT eligible, and community patients, 2% to 15% in SCT ineligible, and 10% to 20% academic patients. Between 2015 to 2019, the use of aCD38 treatments in 3L increased from 10% to >30% in all, standard risk and SCT eligible patients, 10% to 20% in academic patients, and 2% to 20% in community and SCT ineligible patients. Over 40% of 4L+ patients were treated with aCD38 treatments by 2019 regardless of subgroup. As shown in Figure 1, of the patients receiving an IMiD, PI, or IMiD+PI in 1-3L in 2015-2019, 10-25% stayed with the same treatment category (though likely switched drugs within the class), whereas 25-50% switched to a different treatment category, in the next line. These proportions generally hold regardless of subgroup. Of the patients receiving an aCD38 regimen in 1-2L in 2015-2019, 10-20% stayed with the same treatment category, 5-40% switched to a different treatment category, and 5-25% stayed with an aCD38 regimen but switched to a different combination in the next line. Of 3L patients receiving an aCD38 regimen, under 15% stayed with the same treatment category, 5-40% switched to a different treatment category, and 1-40% stayed with an aCD38 regimen but switched to a different combination in 4L.

Conclusions: Our findings suggest that across lines, IMiD, PI, and IMiD+PI are the most common treatment categories but that aCD38 treatments are increasingly used in recent years and in later lines. For the major treatment categories (IMiD, PI, IMiD+PI), <25% patients will remain with the same treatment category, whereas 25-50% will switch to another treatment category, in the next line. For aCD38 treatments, 20% or less will remain with the same treatment category, whereas 5-40% will switch, in the next line.

Disclosures

Gershon:Genentech, Inc./ F. Hoffmann-La Roche: Current Employment, Current equity holder in publicly-traded company. Liu:Genesis Research receives consulting fees from Genentech, Inc. a member of the F. Hoffmann-La Roche Group: Consultancy; Genesis Research: Current Employment. James:Genentech, Inc./ F. Hoffmann-La Roche: Current Employment, Current equity holder in publicly-traded company. Williamson:Amgen: Current equity holder in publicly-traded company; F. Hoffmann-La Roche: Current Employment, Current equity holder in publicly-traded company. Hong:Genentech, Inc.: Current Employment; F. Hoffmann-La Roche: Current equity holder in publicly-traded company. Sarsour:F. Hoffmann-La Roche: Current equity holder in publicly-traded company; Genentech, Inc.: Current Employment.

Author notes

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Asterisk with author names denotes non-ASH members.