The following article features coverage from the 2021 Annual Meeting of the Society of Hematologic Oncology (SOHO). Click here to read more of Cancer Therapy Advisor’s conference coverage.

Real-world data showed poor survival for patients with multiple myeloma (MM) who went on to subsequent therapy after completing treatment with a proteasome inhibitor (PI), an immunomodulatory agent (IMiDs), and an anti-CD38 monoclonal antibody (mAb).

Researchers discovered a “high degree of reuse” of PIs, IMiDs, and anti-CD38 mAbs in these patients, as well as a short duration of treatment after initial triple-class exposure.

“The high proportion of triple-class agent reuse, short durations of additional treatments post triple-class exposure, and poor survival in this setting all highlight the … need for new agents with novel mechanisms to improve survival and quality of life in these triple-refractory patients,” said Robert Smith, MD, of Integra Connect in West Palm Beach, Florida.


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Dr Smith presented these findings at the Annual Meeting of the Society of Hematologic Oncology (SOHO).1

Dr Smith noted that results from the MAMMOTH study showed a median overall survival of 9.2 months in triple-exposed MM patients.2 However, he said, real-world data from patients treated in a community-based setting are scarce.

With that in mind, Dr Smith and colleagues evaluated outcomes of 1399 MM patients from 12 large community networks who had started triple-class therapy. In this group, 501 patients completed triple-class therapy and received subsequent treatment.

The researchers found that, compared with patients from the MAMMOTH study2, patients in the current study reached triple exposure in a shorter time period and with a lower median number of lines of therapy.

The patients achieved triple exposure with a median of 3 lines of therapy. The median time from the start of the first line of therapy to completion of triple exposure was 995 days.

All patients received daratumumab, which was the only anti-CD38 mAb approved at the time of the study. Daratumumab was then reused in 31.3% of patients.

The most commonly used PI was bortezomib (91%), followed by carfilzomib (80.6%), and ixazomib (32.1%). Ixazomib was reused in 19.6% of patients, bortezomib was reused in 29.5%, and carfilzomib was reused in 48.1%.

The most commonly used IMiDs were lenalidomide (93%) and pomalidomide (82.2%), although thalidomide was used as well (9%). Thalidomide was reused in 6% of patients, lenalidomide was reused in 30.9%, and pomalidomide was reused in 46.7%.

After initial triple exposure, most patients (74.6%) received a combination of triple-class agents and other agents, such as elotuzumab, panobinostat, or selinexor.

Of the remaining patients, 20.6% received repeat treatment with triple-class agents exclusively, and 4.8% of patients received treatment outside of triple-class agents.

Consistent with findings from MAMMOTH2, the current study showed poor outcomes and short durations of subsequent lines of therapy after triple exposure. The median duration of subsequent lines of therapy was 78 days. The median survival from the initiation of subsequent agents was 308 days.

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

Read more of Cancer Therapy Advisor’s coverage of SOHO 2021 by visiting the conference page.

Reference

  1. Smith R, Xue M, Dorrow N, et al. Real-world treatment patterns and outcomes of triple exposed multiple myeloma (MM) patients treated in community oncology practices in the US. Paper presented at: Annual Meeting of the Society of Hematologic Oncology (SOHO); September 8-11, 2021.
  2. Gandhi UH, Cornell RF, Lakshman A, et al. Outcomes of patients with multiple myeloma refractory to CD38 targeted monoclonal antibody therapy. Leukemia. 2019;33(9): 2266 75. doi:10.1038/s41375-019-0435-7