A Study of Melphalan Flufenamide (Melflufen) Plus Dexamethasone in Patients With Relapsed or Refractory Multiple Myeloma (HORIZON)

A Single Arm, Open-Label, Phase 2 Study of Melflufen in Combination With Dexamethasone in Patients With Relapsed Refractory Multiple Myeloma Who Are Refractory to Pomalidomide and/or an Anti-CD38 Monoclonal Antibody

This study will evaluate melflufen in combination with dexamethasone in adult patients with relapsed or refractory multiple myeloma in whose disease is refractory to pomalidomide and/or an anti-CD38 monoclonal antibody. All patients in the study will be treated with melflufen on Day 1 and dexamethasone on Days 1, 8, 15 and 22 of each 28-day cycle.

Study Overview

• Status: Completed
• Conditions: Multiple Myeloma
• Intervention / Treatment: Drug: Melphalan flufenamide (Melflufen); Drug: Dexamethasone

Detailed Description

Melphalan flufenamide (melflufen) is a peptide-drug conjugate that rapidly delivers an alkylating payload into tumor cells. Peptidases are expressed in several cancers, including solid tumors and hematologic malignancies. Melphalan flufenamide is rapidly taken up by myeloma cells due to its high lipophilicity. Once inside the myeloma cell, the activity of melphalan flufenamide is determined by its immediate cleavage by peptidases into hydrophilic alkylator payloads that are entrapped. Melphalan flufenamide is 50-fold more potent than melphalan in myeloma cells in vitro due to increased intracellular alkylator concentration. It rapidly induces irreversible DNA damage leading to apoptosis of myeloma cells. Melphalan flufenamide displays cytotoxic activity against myeloma cell lines resistant to other treatments, including alkylators, in vitro. Melphalan flufenamide also has demonstrated inhibition of angiogenesis and DNA damage with a lack of functional DNA repair in preclinical studies.

• Study Type: Interventional
• Enrollment (Actual): 157
• Phase: Phase 2

Contacts and Locations

Study Locations

• France
  • Nantes, France, 44000
    • CHU de Nantes
  • Poitiers, France, 86021
    • CHU de Poitiers
• Italy
  • Bologna, Italy, 40126
    • Universita di Bolognia
  • Turin, Italy, 10126
    • Turin Hospital Myeloma Unit
• Spain
  • Barcelona, Spain, 08036
    • Hospital Clinic i Provincial de Barcelona
  • Barcelona, Spain, 08916
    • Institut Catalá d'Oncologia (ICO) BADALONA
  • Madrid, Spain, 28040
    • Hospital Universitario Fundacion Jimenez Diaz
  • Madrid, Spain, 28006
    • Hospital Universitario de La Princesa
  • Pamplona, Spain, 31008
    • Clinica Universidad de Navarra
  • Salamanca, Spain, 37007
    • Complejo Hospitalario de Salamanca
  • Valencia, Spain, 46017
    • Hospital Universitario Doctor Peset
• United States
  • California
    • Whittier, California, United States, 90603
      • Innovative Clinical Research Institute (ICRI)
  • Florida
    • Gainesville, Florida, United States, 32610
      • University of Florida
  • Illinois
    • Chicago, Illinois, United States, 60612
      • Rush
  • Massachusetts
    • Boston, Massachusetts, United States, 02215
      • Dana Farber Cancer Institute
  • Michigan
    • Detroit, Michigan, United States, 48201
      • Karmanos Cancer Center
  • New York
    • New York, New York, United States, 10065
      • Memorial Sloan Kettering Cancer Center
    • Poughkeepsie, New York, United States, 10532
      • Hudson Valley Hematology Oncology
  • Pennsylvania
    • Pittsburgh, Pennsylvania, United States, 15232
      • UPMC Hillman Cancer Insitute
  • Texas
    • Dallas, Texas, United States, 75246
      • Baylor

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Male or female, age 18 years or older
• A prior diagnosis of multiple myeloma with documented disease progression
• Measurable disease based on either of a) serum monoclonal protein by protein electrophoresis (SPEP), b) monoclonal protein in the urine on 24-hour urine electrophoresis (UPEP), and/or c) serum immunoglobulin free light chain combined with abnormal serum immunoglobulin kappa to lambda free light chain ratio
• A minimum of 2 prior lines of therapy including an IMiD and a PI and is refractory to pomalidomide and/or daratumumab
• Life expectancy of ≥ 6 months
• Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2
• Female of child bearing potential (FCBP) and non-vasectomized male agree to practice appropriate methods of birth control
• Ability to understand the purpose and risks of the study and provide signed and dated informed consent and authorization to use protected health information
• 12-lead ECG with QTc interval within defined limit
• Acceptable laboratory results during screening and prior to first study drug administration of the following parameters: absolute neutrophil count (ANC), platelet count, hemoglobin, total bilirubin, aspartate transaminase (AST/SGOT) and alanine transaminase (ALT/SGPT), renal function based on estimated creatinine clearance
• Must have, or accept to have, an acceptable central catheter for infusion of melflufen

Exclusion Criteria:

• Evidence of mucosal or internal bleeding and/or is platelet transfusion refractory
• Any medical conditions that, in the Investigator's opinion, would impose excessive risk to the patient or would adversely affect his/her participating in this study
• Known active infection requiring parenteral or oral anti-infective treatment within defined period
• Primary refractory disease
• Other malignancy diagnosed or requiring treatment within the defined period with specific exceptions
• Pregnant or breast-feeding females
• Serious psychiatric illness, active alcoholism, or drug addiction that may hinder or confuse compliance or follow-up evaluation
• Known HIV or active hepatitis B or C viral infection
• Concurrent symptomatic amyloidosis or plasma cell leukemia
• POEMS syndrome [plasma cell dyscrasia with polyneuropathy, organomegaly, endocrinopathy, monoclonal protein (M-protein) and skin changes]
• Previous cytotoxic therapies, including cytotoxic investigational agents, for multiple myeloma within defined values prior to start of study treatment
• Residual side effects to previous therapy over specific grade prior to initiation of therapy
• Prior autologous or allogeneic stem cell transplant within defined period of initiation of therapy
• Prior allogeneic stem cell transplant with active graft-versus-host- disease (GVHD).
• Prior major surgical procedure or radiation therapy within specified period of the first dose of study treatment (with defined exception).
• Known intolerance to steroid therapy

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: melphalan flufenamide (melflufen) + dexamethasone; Melphalan flufenamide (melflufen) 40 mg Day 1 and dexamethasone 40 mg (20 mg for patients 75 years or older) on Days 1, 8, 15 and 22 of each 28-day cycle.	Drug: Melphalan flufenamide (Melflufen); Other Names: Pepaxto; Drug: Dexamethasone; IV dexamethasone may be substituted for oral dexamethasone in the US. Oral only in Europe.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Overall Response Rate (ORR)	The overall response rate (ORR) will be estimated as the percentage of patients who achieve sCR, CR, VGPR, or PR as their best response as assessed by the investigator. Response assessed by IMWG (International myeloma working group) criteria sCR-stringent complete response: CR plus Normal FLC (free light chain) ratio and absence of clonal cells in BM CR-complete response: Negative immunofixation in serum/urine; Disappearance of soft tissue plasmacytomas; <5% plasma cells in BM; If only FLC disease, normal FLC ratio (0.26-1.65) VGPR-very good partial response: Serum/urine M-protein detectable by immunofixation but not electrophoresis or ≥90% reduction in serum M-protein and urine M-protein <100 mg/24 h; If only FLC disease, >90% decrease in the difference between involved and uninvolved FLC levels PR-partial response: 50% reduction of serum M-protein and soft tissue plasmacytomas, ≥90% reduction in urinary M-protein or to <200 mg/24 h; other special cases if M-protein unmeasurable	Patients were followed until documented progression, unacceptable toxicity, patient/physician decision to withdraw or date of death, whichever came first. Longest time to response in study recorded as 15.3 months. Longest time on treatment 35 months.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Progression Free Survival (PFS)	Time from start of treatment to either progression or death, whichever comes first as assessed by the investigator using IMWG criteria. Progression of disease is defined by an increase of 25% from the lowest response for either of Serum M-component (absolute increase of ≥ 0.5 g/dL) or Urine M-component (absolute increase of ≥200 mg/ 24h); In patients without measurable M-protein a 25% increase in the difference between involved and uninvolved FLC (free light chain) levels (absolute increase must be >10 mg/dL); If unmeasurable FLC levels, a 25% increase in bone marrow plasma cell percentage (absolute percentage must be >10%); New bone or soft tissue plasmacytomas or definite increase in existing ones; Development of hypercalcemia (corrected serum calcium >11.5 mg/dL) that can be attributed solely to the plasma cell proliferative disorder	Patients were followed until documented progression, unacceptable toxicity, patient/physician decision to withdraw or date of death, whichever came first. Longest follow-up time for PFS recorded as 37.2 months at study end.
Duration of Response	Time from first response to progression based on investigator assessment. See definitions of response and progression in ORR and PFS outcomes.	From date of response until the date of first documented progression or date of death from any cause, whichever came first. Longest time of response recorded as 36.2 months at study end.
Overall Survival	Time from start of treatment to death	From date of first dose of study medication until the date of death from any cause, assessed up to 24 months after study drug discontinuation.
Functional Status and Well-being: EORTC QLQ-C30	Change from baseline in Patient Reported Outcome questionnaire EORTC QLQ-C30. The EORTC QLQ-C30 includes 30 items resulting in 5 functional scales, 1 Global Health Status scale, 3 symptom scales, and 6 single items. The recall period is 1 week (the past week). The scales are transformed to a 0 (worst) to 100 (best) scale. The QLQ-C30 summary score is calculated as the mean of the combined 13 QLQ-C30 scale and item scores (excluding global QoL and financial impact), with a higher score indicating a better HRQoL. If at least 50% of the items from the scale had been answered, the missing items were assumed to have values equal to the average of those items which were present for that respondent.	To be assessed prior to dosing at Cycle 1, 2, 4, 6, 8, and End of Treatment. 23 patients were ongoing for QoL assessments at data cutoff. QoL was added in Protocol Amendment 4 beginning in Oct. 2018.
Functional Status and Well-being: EQ-5D-3L	Change from baseline in Patient Reported Outcome questionnaire EQ-5D-3L. The EQ-5D-3L questionnaire converts 5 dimensions: Mobility, Self-Care, Usual Activities, Pain/Discomfort, and Anxiety/Depression of patient-reported, current-day health status into a "health utility" score. For the EQ-5D-3L questionnaire, each dimension is scored on an ordinal scale with 3 available levels of response and scores ranging from 1 to 3, "no problems," "some problems," and "extreme problems," respectively. The EQ VAS scores rates "health today" with anchors ranging from 0 (worst imaginable health state) to 100 (best imaginable health state). No imputation of missing items or composite scores were done. The scores for the 5 dimensions are used to compute a single utility score ranging from zero (0.0) to 1 (1.0) representing the general health status of the individual.	To be assessed prior to dosing at Cycle 1, 2, 4, 6, 8, and End of Treatment. 23 patients were ongoing for QoL assessments at data cutoff. QoL was added in Protocol Amendment 4 beginning in Oct. 2018.
Clinical Benefit Rate	The clinical benefit rate (CBR) will be estimated as the percentage of patients who achieve sCR, CR, VGPR, PR, or MR as their best response as assessed by the investigator. See Primary Outcome (ORR) for definitions of response categories.	Patients were followed until documented progression, unacceptable toxicity, patient/physician decision to withdraw or date of death, whichever came first. Longest time on study treatment recorded as 35.0 months at study end.
Time to Response	Duration from start of treatment to the first occurrence of a confirmed response of PR or better as assessed by the investigator. See definitions of response in Primary Outcome (ORR).	From start of treatment to first confirmed response. Longest time to response in study recorded as 15.3 months.
Time to Progression	Duration from start of treatment to first evidence of disease progression as assessed by the investigator. See definitions of response and progression in ORR and PFS outcomes.	From start of treatment to first evidence of disease progression or date of death from any cause, whichever came first. Longest time to progression recorded was 37.2 months at study end.

Collaborators and Investigators

• Sponsor: Oncopeptides AB
• Collaborators: Precision For Medicine
• Investigators: Study Chair: Johan Harmenberg, MD, PhD, Oncopeptides AB

Publications and helpful links

General Publications

• Richardson PG, Oriol A, Larocca A, Blade J, Cavo M, Rodriguez-Otero P, Leleu X, Nadeem O, Hiemenz JW, Hassoun H, Touzeau C, Alegre A, Paner A, Maisel C, Mazumder A, Raptis A, Moreb JS, Anderson KC, Laubach JP, Thuresson S, Thuresson M, Byrne C, Harmenberg J, Bakker NA, Mateos MV; HORIZON (OP-106) Investigators. Melflufen and Dexamethasone in Heavily Pretreated Relapsed and Refractory Multiple Myeloma. J Clin Oncol. 2021 Mar 1;39(7):757-767. doi: 10.1200/JCO.20.02259. Epub 2020 Dec 9.
• Larocca A, Leleu X, Touzeau C, Blade J, Paner A, Mateos MV, Cavo M, Maisel C, Alegre A, Oriol A, Raptis A, Rodriguez-Otero P, Mazumder A, Laubach J, Nadeem O, Sandberg A, Orre M, Torrang A, Bakker NA, Richardson PG. Patient-reported outcomes in relapsed/refractory multiple myeloma treated with melflufen plus dexamethasone: analyses from the Phase II HORIZON study. Br J Haematol. 2022 Feb;196(3):639-648. doi: 10.1111/bjh.17887. Epub 2021 Oct 21. Erratum In: Br J Haematol. 2022 Aug;198(3):609.

Study record dates

Study Major Dates

• Study Start (Actual): December 28, 2016
• Primary Completion (Actual): October 22, 2020
• Study Completion (Actual): November 16, 2021

Study Registration Dates

• First Submitted: October 18, 2016
• First Submitted That Met QC Criteria: November 10, 2016
• First Posted (Estimate): November 15, 2016

Study Record Updates

• Last Update Posted (Actual): November 22, 2022
• Last Update Submitted That Met QC Criteria: November 18, 2022
• Last Verified: November 1, 2022

More Information

Terms related to this study

• Keywords: relapsed refractory multiple myeloma
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Vascular Diseases; Immune System Diseases; Neoplasms by Histologic Type; Neoplasms; Lymphoproliferative Disorders; Immunoproliferative Disorders; Hematologic Diseases; Hemorrhagic Disorders; Hemostatic Disorders; Paraproteinemias; Blood Protein Disorders; Multiple Myeloma; Neoplasms, Plasma Cell; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Autonomic Agents; Peripheral Nervous System Agents; Anti-Inflammatory Agents; Antineoplastic Agents; Immunosuppressive Agents; Immunologic Factors; Antiemetics; Gastrointestinal Agents; Glucocorticoids; Hormones; Hormones, Hormone Substitutes, and Hormone Antagonists; Antineoplastic Agents, Hormonal; Antineoplastic Agents, Alkylating; Alkylating Agents; Myeloablative Agonists; Dexamethasone; Melphalan
• Other Study ID Numbers: OP-106