Real-World Patient Characteristics and Outcomes in China Multiple Myeloma Patients with Unmet Needs
Authors: Cui Jian , Shen Dan , Liu Gang , Qiu Lu-Gui , An Gang 
Published: December 2024

Introduction：

Multiple myeloma (MM) is a malignant clonal plasma cell disorder and the second most common hematologic malignancy worldwide. Relatively little is known about the clinical features of multiple myeloma (MM) in China, particularly in populations with 1q abnormalities, renal impairment (RI), the elderly, and those refractory to lenalidomide (R) or bortezomib (V), all facing considerable unmet needs due to limited treatment options. This study aimed to present real-world characteristics and clinical outcomes for these specific populations in China.

Methods：

A retrospective observational study was conducted using pre-existing electronic medical records (EMRs) data from the Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College. All patients aged ≥ 18 years who were initially diagnosed with active MM between Jan 1, 2018, and Dec 31, 2022, were included. Baseline was defined as 14-days prior to the first diagnosis of MM. The data collection period spanned from baseline and followed up until last contact, death, or end of study (Dec 31, 2023), whichever occurred first. Clinical outcomes, including overall response rate (ORR), progression-free survival (PFS) rate at 12 month and time to progression (TTP), were determined by the physician or based on laboratory criteria according to the International Myeloma Working Group response criteria.

Results：Of 579 newly diagnosed MM (NDMM) patients included, the median age was 59.00 (Interquartile Range [IQR]: 52.00, 65.00) years, with 51.81% being male. There were 85.45% of patients in Durie-Salmon (D-S) stage III, 33.63% and 43.94% in International Staging System (ISS) stage II and III, respectively. The most frequent M protein types were IgG (47.40%), light chain (22.92%), and IgA (22.40%). A total of 41.97% patients underwent transplantation as part of frontline treatment.

The physician reported ORR of frontline treatment in MM patients was 91.45% (503/550, 95% CI: 88.80%, 93.65%), with a real world PFS rate of 92.81% (95%CI: 90.63%, 95.05%) at 12 month and a median TTP of 20.10 (IQR: 12.07, 33.30) months. The median PFS was not reached for frontline treatment.

At baseline, 29.71% (172/579, 95% CI: 26.01%, 33.61%) of the patients were aged ≥ 65 years. The ORR of frontline treatment in this elderly group was 87.26% (137/157, 95% CI: 81.01%, 92.04%), with a PFS rate of 92.09% (95%CI: 87.88%, 96.50%) at 12 month and a median TTP of 18.13 (IQR: 11.78, 30.32) months. The proportion of patients with RI (eGFR &lt; 60 ml/min/1.73m2) at baseline was 23.06% (101/438, 95%CI: 19.19%, 27.29%). For these RI patients, the ORR of frontline treatment was 91.40% (85/93, 95% CI: 83.75%, 96.21%), with a PFS rate of 91.16% (95%CI: 85.48%, 97.21%) at 12 month and a median TTP of 20.07 (IQR: 11.84, 31.64) months. The presence of 1q abnormalities was identified in 43.46% of patients at baseline (166/382, 95%CI: 38.42%, 48.59%). The ORR of frontline treatment for these patients was 94.34% (150/159, 95%CI: 89.53%, 97.38%), with a PFS rate of 91.37% (95%CI: 86.98%, 95.98%) at 12 month and a median TTP of 24.52 (IQR: 11.98, 39.18) months. The proportion of patients who were refractory to R and/or V after frontline treatment was 3.35% (19/567, 95%CI: 2.03%, 5.18%).

In frontline treatment, 138 (23.83%) patients received a daratumumab-based regimen (dara). The median age of these patients was 58.00 (IQR:53.00, 65.00) years, with 31.16% being aged ≥ 65 years. The distribution of patients by disease stage was as follows: 92.19% were in D-S stage III, 33.33% and 46.97% were in ISS stage II and III, respectively. Regarding treatment regimens, 52.17% of those patients received a combination of dara, immunomodulatory drugs (IMiDs), and protease inhibitors (PIs), 15.22% received dara combined with PIs, and 12.32% received dara combined with IMiDs.

Conclusion：

This real-world observational showed that 1q abnormalities, advanced age and RI are prevalent among Chinese MM patients, affecting their clinical outcomes. Over 20% of patients with late disease D-S stage received dara in their frontline treatment, among which only half received a dara-based quadruplet therapy. Continuous attention to these groups is necessary to improve their prognosis through novel regimens.