Main Treatment Choices in the 2 First Lines of Therapy for Multiple Myeloma in Patients with High Risk Cytogenetics: Lesson from the Real World in the EU5 Countries and the USA

Abstract

Background Typical approach to initial therapy in multiple myeloma (MM) includes more aggressive combinations early on with triplets. To further improve response rates and survival, quadruplets are moving to frontline, in both stem cell transplant (SCT) eligible and ineligible patients (pts). Defining high risk features is crucial; current international NCCN and IMWG clinical practice guidelines stratify pts based on those criteria proposing more aggressive therapy in this setting. Definitions of high risk are: cytogenetic abnormalities incl. del(17p), some laboratory factors with ISS III and increased LDH, some clinical features including plasma cell leukaemia, extramedullary involvement or age and functional assessment with primary refractory disease and rapid progression within 18 months of diagnosis. Aims Identify in real world setting the main regimens used in first line SCT eligible and ineligible pts as well as in 2nd line high risk pts with MM in EU5 countries (France, Germany, Italy, Spain, UK) and in the USA. Methods Anonymous patient charts were analysed based on data reported by onco-haematologists treating MM pts in EU5 countries and USA. A total of 1,575 unique patient charts in 1st line (530 SCT eligible and 1,045 SCT ineligible pts) and 1,665 unique pts in 2nd line were included in the analysis, from Oct. to Dec. 2022. The analysis focused on pts with high risk cytogenetic features and regimens used in accordance with international clinical practice guidelines. D= daratumumab; V=bortezomib; T=thalidomide; d= dexamethasone; R=lenalidomide; M= melphalan; p= prednisone; K=carfilzomib; Isa=isatuximab Results Mean age in 1st line SCT eligible pts was 59.0 years (n=441) in EU5 and 60.9 years (n=89) in the USA. In 1st line SCT ineligible pts, mean age was 74.0 years (n=838) in EU5 and 65.9 years (n=207) in the USA. Among all 1st line SCT eligible pts, 34% in EU5 and 29% in US had high risk cytogenetic features, with del17p identified in 12% of EU5 cases and 16% of US cases. In 1st line SCT ineligible pts in the EU5 and in the US 14% and 17% respectively were high risk, including 9% and 13% del17p. In the 2nd line setting, 1,208 unique pts were included in the EU5 and 457 in the US with 17% and 14% classified at high risk, respectively, del17p was identified in 9% and 11% of pts. The most frequently used regimens in 1st line SCT eligible pts in EU5 are D-VRd (n=56), VRd (n=69) and D-VTd (n=136) with 41% and 39% of high-risk pts. In the US, the most frequent regimens used in this subset were D-VRd (n=17) and VRd (n=33) with 35% and 39% of pts belonging to the high-risk group. For 1st line SCT ineligible pts in EU5, 40% of patients were high risk, with the most common regimen being VRd (n=67). Pts with del17p were also overrepresented in this subgroup with 15% of total population receiving VRd. Other frequently used regimens were D-VMP (n=95), DRd (n=188), Rd (n=148) and VMP (n=80) but none was preferred in high-risk pts. In the US, the most frequently-used regimen in 1st line SCT ineligible population was VRd (n=73) with 27% of pts with high-risk features (vs. 17% in the overall population). For 2nd line treatment in the EU5, carfilzomib-based combinations are more frequently used in high-risk pts, particularly DKd (n=42) and KRd (n=118), both associated with 35% of pts with high-risk features. Kd was also regularly used in this subset (n=76) with 32% of high-risk pts. Despite a small number of pts (n=29), Isa-Kd triplet is more regularly used in pts with del17p (21% of all pts). In 2nd line setting in the USA, the most frequently used regimen was DKd (n=37) with 30% high-risk pts. In pts with del17p, Kd was regularly used (n=14) with 21% of pts presenting this abnormality. Among other regimens, such as DPd (n=38), Dd (n=30), DRd (n=35) and KRd (n=21), none was preferred in high-risk pts. Conclusion This real-world study reveals quite heterogeneous treatment choices in 1st and 2nd line pts with high-risk cytogenetic features with no large consensus, especially between EU5 and the US. Some trends can be identified between different pts subsets: quadruplets with D-VRd and D-VTd in EU5 and D-VRd in the US are preferred as induction treatment prior to SCT. VRd is regularly used in 1st line SCT ineligible pts in the EU5, particularly in case of del17p. Carfilzomib-based regimens are more common in 2nd line pts in both EU5 and US, especially DKd, KRd and Kd. Those are in line with the main international guidelines and expert recommendations for high-risk pts.