Real-world characterization of patients with advanced or metastatic dedifferentiated liposarcoma (DDLPS) in Japan in MASTER KEY project

BackgroundInformation on the epidemiology of DDLPS, a subgroup of liposarcoma (LPS), in Japan is scarce and the efficacy of available treatments is limited. We used the existing MASTER KEY Registry Database to inform the epidemiology and clinical outcomes of patients (pts) with advanced/metastatic LPS treated with systemic antineoplastic therapy in Japan.MethodsIn this non-interventional/observational cohort study, pts with LPS and a history of systemic antineoplastic therapy for LPS enrolled in the MASTER KEY Project Registry Database from May 1, 2017 to Dec 31, 2022 were included. Data were collected up to May 15, 2023. We assessed pts with advanced/metastatic LPS (Cohort 1; C1) and advanced/metastatic DDLPS (Cohort 2; C2) treated with first-line (1L) pharmacotherapy with any drug, or with 1L doxorubicin (DXR) monotherapy. Here, we present real-world (rw) progression-free survival (PFS), defined as time from index date [date of 1L treatment initiation] to disease progression, end of treatment, or death, and rw overall survival (OS), defined as time from index date to death. Sensitivity analyses (prospective registry subgroup) were performed to minimize immortal time bias.ResultsSince 2017, 100 pts (C1) and 62 pts (C2) were enrolled; 50 (50.0%; C1) and 34 (54.8%; C2) were male. Response rates are shown in the table. In pts with LPS (C1), median age at diagnosis was 59.5 y and 47 pts received 1L DXR. Median rwPFS in LPS pts treated with 1L DXR was 6.9 months (95% CI: 3.1–13.8). In pts with DDLPS (C2), median age at diagnosis was 63.0 y and 34 pts received 1L DXR. Median rwPFS in DDLPS pts treated with 1L DXR was 4.4 months (95% CI: 2.5–9.0); the median rwOS of 13.9 months (3.9–NR) in the sensitivity analysis was similar to previous reports. Table: 1746P Response rates for pts with LPS and DDLPS LPS (Cohort 1) DDLPS (Cohort 2) 1L pharmacotherapy Doxorubicin monotherapy (1L pharmacotherapy) 1 L pharmacotherapy Doxorubicin monotherapy (1L pharmacotherapy) Total, n (%) 97 47 60 34 CR 2 (2.1) 0 (0.0) 1 (1.7) 0 (0.0) PR 12 (12.4) 5 (10.6) 7 (11.7) 4 (11.8) SD 39 (40.2) 22 (46.8) 23 (38.3) 14 (41.2) PD 27 (27.8) 17 (36.2) 22 (36.7) 15 (44.1) NE 8 (8.2) 2 (4.3) 5 (8.3) 1 (2.9) Unknown 8 (8.2) 1 (2.1) 1 (1.7) 0 (0.0) Missing 1 (1.0) 0 (0.0) 1 (1.7) 0 (0.0) ORR, % 14.4 10.6 13.3 11.8 DCR, % 54.6 57.4 51.7 52.9 CR, complete response; DCR, disease control rate; NE, not evaluable; ORR, overall response rate; PD, progressive disease; PR, partial response; SD, stable disease ConclusionsThese first data investigating DDLPS in Japanese pts suggest they have higher unmet needs among pts with LPS due to limited efficacy of currently available treatments, with a shorter PFS observed for pts with DDLPS versus LPS.Editorial acknowledgementMedical writing support for the development of this abstract, under the direction of the authors, was provided by Lorena Mejias Martinez of Ashfield MedComms, an Inizio Company, and funded by Nippon Boehringer Ingelheim.Legal entity responsible for the studyNippon Boehringer Ingelheim.FundingNippon Boehringer Ingelheim.DisclosureK. Tsuchihashi: Financial Interests, Personal, Invited Speaker: Taiho Pharma. E. Baba: Financial Interests, Personal, Advisory Board: Astellas, Daiichi Sankyo, AstraZeneca, Eli Lilly, Chugai, Taiho, Ono pharma, MSD, Merck, Takeda, Bayer, Janssen; Financial Interests, Personal, Invited Speaker: Daiichi Sankyo; Financial Interests, Institutional, Research Grant: Chugai, Eli Lilly, Taiho. I. Kinoshita: Financial Interests, Personal, Invited Speaker, Invited Speaker: MSD Pharmaceutical; Financial Interests, Personal, Invited Speaker, Invited Speaker, chairperson of lecture: Bayer; Financial Interests, Personal, Invited Speaker, Invited Speaker: Takeda Pharmaceutical, Konica Minolta Realm; Financial Interests, Personal, Other, chairperson of lecture: Chugai Pharma, Novartis Pharma, Guardant Health Japan; Financial Interests, Personal and Institutional, Local PI, local PI: Daiichi Sankyo; Financial Interests, Personal and Institutional, Research Grant, research grant: Konica Minolta Realm; Financial Interests, Personal and Institutional, Local PI, Local PI: Eisai. M. Muto: Financial Interests, Personal, Invited Speaker: Chugai, MSD, Ono pharma, Meiji Seika Pharma, Novartis, Taiho; Non-Financial Interests, Advisory Role: KBBM, PRiME-R. W. Sakamoto, Y. Hirata: Financial Interests, Personal, Full or part-time Employment: Nippon Boehringer Ingelheim Co., Ltd. K. Nakamura: Financial Interests, Personal, Invited Speaker: Chugai, Taiho, AstraZeneca, Lilly, Takeda. K. Yonemori: Financial Interests, Personal, Advisory Board: Eisai, AstraZeneca, Sanofi, Genmab, Gliad, OncXerna, Takeda, Novartis, MSD, Henlius; Financial Interests, Personal, Invited Speaker: Pfizer, Eisai, AstraZeneca, Eli Lilly, Takeda, Chugai, Fuji Film Pharma, PDR Pharma, MSD, Boehringer Ingelheim, Ono Pharma, Daiichi Sankyo, Bayer, Janssen, Asteras, Bristol Myers Squibb, Novartis, Sanofi, Merck BioPharma; Financial Interests, Institutional, Research Grant: MSD, Daiichi Sankyo, Merck BioPharma, AstraZeneca, Taiho, Pfizer, Novartis, Takeda, Chugai, Ono Pharma, Sanofi, Seattle Genetics, Eisai, Eli Lilly, Genmab, Boehringer Ingelheim, Kyowa Hakko Kirin, Nihon Kayaku, Haihe; Financial Interests, Institutional, Principal Investigator: MSD, Daiichi Sankyo, Genmab, Seagen, AstraZeneca, Taiho, Merck BioPharma, Pfizer, Novartis, Takeda, Chugai, Ono Pharma, Sanofi, Seattle Genetics, Eisai, Eli Lilly, Genmab, Boehringer Ingelheim, Kyowa Hakko Kirin, Nihon Kayaku, Haihe. All other authors have declared no conflicts of interest.