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3477 HORIZON (OP-106): Melflufen Plus Dexamethasone (dex) in Patients (pts) with Relapsed/Refractory Multiple Myeloma (RRMM) — Health-Related Quality of Life (HRQoL) Analysis

Program: Oral and Poster Abstracts
Session: 905. Outcomes Research—Malignant Conditions (Lymphoid Disease): Poster III
Hematology Disease Topics & Pathways:
multiple myeloma, Non-Biological, Diseases, Therapies, chemotherapy, Plasma Cell Disorders, Lymphoid Malignancies, Quality Improvement
Monday, December 7, 2020, 7:00 AM-3:30 PM

Albert Oriol1*, Paul G. Richardson, MD2, María-Victoria Mateos, MD, PhD3, Alessandra Larocca4, Joan Blade Creixenti5, Michele Cavo6*, Paula Rodríguez-Otero, MD7*, Maxim Norkin, MD, PhD8*, Omar Nadeem, MD2*, John W. Hiemenz, MD9*, Hani Hassoun, MD10, Cyrille Touzeau11,12,13*, Adrián Alegre Amor, MD, PhD14*, Agne Paner, MD15, Christopher Maisel, MD16, Amitabha Mazumder, MD17*, Anastasios Raptis, MD18, Noemí Puig, MD, PhD3*, Peter Strang, MD19*, Anna Sandberg, MmSc20*, Christian Jaques, MD20*, Marcus Thuresson, PhD21*, Marie Orre, PhD20* and Xavier Leleu, MD22

1Institut Català d’Oncologia and Josep Carreras Research Institute, Hospital Germans Trias i Pujol, Badalona, Spain
2Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA
3Hospital Clínico Universitario de Salamanca/IBSAL/CIC, Salamanca, Spain
4Myeloma Unit, Division of Hematology, University of Torino, Azienda Ospedaliero-Universitaria Città della Salute e della Scienza, Torino, Italy
5Hematology Department, IDIBAPS, Hospital Clinic, Barcelona, Spain
6Seràgnoli Institute of Hematology, Bologna University School of Medicine, Bologna, Italy
7Clínica Universidad de Navarra, Pamplona, Spain
8Baptist MD Anderson Cancer Center, Jacksonville, FL
9Division of Hematology-Oncology, Department of Medicine, University of Florida, Gainesville, FL
10Myeloma Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY
11Centre de Recherche en Cancérologie et Immunologie Nantes-Angers (CRCINA), Institut National de la Santé et de la Recherche Médicale (INSERM), Centre National de la Recherche Scientifique (CNRS), Université d'Angers, Université de Nantes, Nantes, France
12Site de Recherche Intégrée sur le Cancer (SIRIC), Imaging and Longitudinal Investigations to Ameliorate Decision-making (ILIAD), INCA-DGOS-Inserm 12558, Nantes, France
13Service d'hématologie Clinique, Centre Hospitalier Universitaire, Place Alexis Ricordeau, Nantes, France
14Hospital Universitario La Princesa and Hospital Universitario Quironsalud, Madrid, Spain
15Rush University Medical Center, Chicago, IL
16Baylor Scott & White Charles A. Sammons Cancer Center, Dallas, TX
17The Oncology Institute of Hope and Innovation, Glendale, CA
18Division of Hematology-Oncology, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA
19Karolinska Institutet, Stockholm, Sweden
20Oncopeptides AB, Stockholm, Sweden
21Statisticon AB, Stockholm, Sweden
22CHU de Poitiers, Poitiers, France

Background: With advances in therapy, outcomes have generally improved for pts with MM; however, pts with late-stage RRMM have limited treatment options and poor outcomes (Kumar et al. Leukemia. 2017;31:2443; Gandhi et al. Leukemia. 2019;33:2266). Pts with late-stage RRMM, often older and having comorbidities, require efficacious and tolerable therapies to maintain HRQoL (Richardson et al. Blood. 2019;134[suppl 1]:3487).

Melphalan flufenamide (melflufen) is a first-in-class peptide-drug conjugate (PDC) that targets aminopeptidases and rapidly releases alkylating agents into tumor cells. In the pivotal, phase 2, HORIZON study (NCT02963493) melflufen plus dex showed an overall response rate of 29%, median progression-free survival of 4.2 months, median overall survival of 11.6 months, and a manageable safety profile (N=157; Richardson et al. EHA 2020. Abs EP945). A previous baseline (BL) HRQoL analysis concluded that the HORIZON population is representative of RRMM populations, with a poor overall HRQoL relative to other populations with advanced cancers (Richardson et al. ASH 2019. Abs 3487). This analysis evaluates HRQoL in pts with RRMM throughout treatment with melflufen plus dex in the HORIZON study.

Methods: Eligible pts received melflufen 40 mg on d1 of each 28-day cycle plus dex 40 mg/wk (20 mg in pts aged ≥75 y). HRQoL was added as a secondary endpoint as an amendment to the HORIZON protocol, which allowed collection of data from a subset of pts using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 V.3 (EORTC QLQ-C30) and the EuroQOL 5 Dimension-3 Level (EQ-5D) questionnaires. EORTC QLC-C30 evaluates functional domains and symptoms on a scale from 0-100 (higher functional scores = better function; higher symptom scores = more symptomatology/problems). The EQ-5D index is evaluated on a scale from 0 (death) to 1 (perfect health) and the EQ-5D VAS is evaluated on a scale from 0 (death) to 100 (perfect health). Questionnaires were administered before dosing at BL (cycle [C] 1) and predose at intervals throughout the study. Descriptive data for pts with post-BL assessments at C2, C4, and C6 are presented herein. Pts with only BL questionnaire assessments were excluded from this analysis. Select EORTC QLQ-C30 and EQ-5D results are presented. This analysis is ongoing.

Results: At HRQoL data cutoff (May 28, 2020), of the 64 pts with post-BL HRQoL assessments, 19 remained on therapy. Among 64 pts in the HRQoL subgroup, median age was 67 y (range, 46-84); 17% had International Staging System stage 3 disease; and 36% had high-risk cytogenetics at study entry. Pts had received a median of 5 prior lines of therapy (range, 2-10). At C2, C4, and C6, 97.9%, 98.9%, and 99.4% of pts with ongoing treatment completed HRQoL assessments.

Mean EORTC QLQ-C30 summary score and mean EQ-5D scores were relatively constant from BL through C6 (Figure). EORTC QLQ-C30 global health status/QoL and emotional functioning had mean scores of 58.6 and 78.4, respectively, at BL and 63.0 and 83.7, respectively, at C6 (Table). Mean symptom scores at BL and C6 for pain were 39.1 and 29.0, respectively, and for fatigue were 39.4 and 38.2, respectively. The EQ-5D VAS and EQ-5D index scores were generally consistent throughout treatment, with mean scores of 61.4 and 0.75, respectively, at BL and 62.3 and 0.74, respectively, at C6.

Among pts with HRQoL data and the overall population (n=64 and N=157, respectively; Jan 14, 2020 data cutoff date), 92% and 89% had ≥1 grade 3/4 AEs, respectively; most common AEs were white blood cell count decreased (42% and 26%), thrombocytopenia (41% and 57%), and anemia (39% and 43%); most common nonhematologic grade 3/4 AEs was pneumonia (14% and 10%). SAEs occurred in 47% of pts in the HRQoL group and 49% of patients overall, most commonly pneumonia (14% and 9%); there were no treatment-related deaths.

Conclusion: The EORTC QLQ-C30 global health status/QoL score and EQ-5D VAS and index scores were consistent from BL throughout treatment, suggesting that melflufen plus dex preserves HRQoL in pts with RRMM. The safety profile of melflufen plus dex consisted primarily of clinically manageable hematologic AEs in the overall pt population. No new safety signals were observed in the HRQoL-evaluable population. These findings are encouraging as treatment-related AEs may negatively affect HRQoL in RRMM. Data should be interpreted with caution due to the attrition of pts over time.

Disclosures: Oriol: Sanofi: Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline: Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen: Consultancy, Speakers Bureau; Janssen: Consultancy. Richardson: Celgene/BMS, Oncopeptides, Takeda, Karyopharm: Research Funding. Mateos: Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Regeneron: Honoraria, Membership on an entity's Board of Directors or advisory committees; Adaptive: Honoraria, Membership on an entity's Board of Directors or advisory committees; Oncopeptides: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline: Honoraria; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees. Larocca: Amgen: Honoraria; GSK: Honoraria; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees. Blade Creixenti: Amgen: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Oncopeptides: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees. Cavo: GlaxoSmithKline: Honoraria, Speakers Bureau; Karyopharm: Honoraria; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel accomodations, Speakers Bureau; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel accomodations, Speakers Bureau; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Rodríguez-Otero: Abbvie: Consultancy; Kite: Consultancy; Amgen: Honoraria; Medscape: Membership on an entity's Board of Directors or advisory committees; Celgene/Bristol Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Sanofi: Consultancy; Janssen: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Oncopeptides: Consultancy; GlaxoSmithKline: Consultancy, Current Employment, Current equity holder in publicly-traded company. Nadeem: Adaptive: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES; Amgen: Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES; Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES. Hassoun: Novartis: Consultancy; Celgene: Research Funding; Takeda: Research Funding. Touzeau: Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Amor: Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene-BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; GSK: Membership on an entity's Board of Directors or advisory committees. Paner: Kayropharm: Consultancy; Amgen: Consultancy; Oncopeptides: Consultancy; Celgene: Consultancy; GSK: Consultancy. Maisel: Incyte: Honoraria, Speakers Bureau; Karyopharm: Honoraria, Speakers Bureau; Janssen: Honoraria, Speakers Bureau; Takeda: Honoraria, Speakers Bureau; Kite: Honoraria, Speakers Bureau; Incyte: Honoraria, Speakers Bureau; Karyopharm: Honoraria, Speakers Bureau; Takeda: Honoraria, Speakers Bureau; Texas Oncology: Current Employment; Amgen: Honoraria, Speakers Bureau; Texas Oncology: Current Employment; Celgene: Honoraria, Speakers Bureau; Kite: Honoraria, Speakers Bureau; Amgen: Honoraria, Speakers Bureau; Janssen: Honoraria, Speakers Bureau; Celgene: Honoraria, Speakers Bureau. Mazumder: Takeda: Honoraria, Speakers Bureau; Celgene: Honoraria, Speakers Bureau; Amgen: Honoraria, Speakers Bureau; The Oncology Institute: Current Employment. Raptis: INTEGRA: Consultancy, Other: TRAVEL, ACCOMMODATIONS, EXPENSES; UPMC: Current Employment. Puig: AMGEN: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES, Research Funding; TAKEDA: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES, Research Funding; BRISTOL-MYERS SQUIBB: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES, Research Funding, Speakers Bureau; JANSSEN: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES, Research Funding; CELGENE: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES, Research Funding, Speakers Bureau; THE BINDING SITE: Consultancy, Honoraria. Strang: Karolinska Institutet: Current Employment; Oncopeptides: Consultancy. Sandberg: Novo Nordisk AS: Divested equity in a private or publicly-traded company in the past 24 months, Ended employment in the past 24 months; Oncopeptides AB: Current Employment. Jaques: Pfizer: Consultancy; Morphosys AG: Consultancy; Oncopeptides: Other: TRAVEL, ACCOMMODATIONS, EXPENSES; Pharma Biotech Consultants: Consultancy; Oncopeptides: Ended employment in the past 24 months. Thuresson: Oncopeptides: Consultancy, Current equity holder in publicly-traded company; Statisticon: Current Employment. Orre: Oncopeptides: Current Employment. Leleu: Janssen: Honoraria.

OffLabel Disclosure: This is a phase 2 investigational study of melflufen in RRMM.

*signifies non-member of ASH