Title

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

    Phase 2
  • Study Type

    Interventional
  • Intervention/Treatment

    urea melphalan ...
  • Study Participants

    157
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.
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 Started
Dec 28
2016
Primary Completion
Oct 22
2020
Study Completion
Nov 16
2021
Results Posted
Feb 01
2022
Last Update
Nov 22
2022

Drug Melphalan flufenamide (Melflufen)

  • Other names: Pepaxto

Drug Dexamethasone

IV dexamethasone may be substituted for oral dexamethasone in the US. Oral only in Europe.

melphalan flufenamide (melflufen) + dexamethasone Experimental

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.

Criteria

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

Summary

Melphalan Flufenamide (Melflufen) + Dexamethasone: Full Analysis Set

Melphalan Flufenamide (Melflufen) + Dexamethasone: Patients With Extramedullary Disease

Melphalan Flufenamide (Melflufen) + Dexamethasone: Patients With Triple Class Refractory Disease

All Events

Event Type Organ System Event Term Melphalan Flufenamide (Melflufen) + Dexamethasone: Full Analysis Set Melphalan Flufenamide (Melflufen) + Dexamethasone: Patients With Extramedullary Disease Melphalan Flufenamide (Melflufen) + Dexamethasone: Patients With Triple Class Refractory Disease

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

Melphalan Flufenamide (Melflufen) + Dexamethasone: Full Analysis Set

Melphalan Flufenamide (Melflufen) + Dexamethasone: Patients With Extramedullary Disease

Melphalan Flufenamide (Melflufen) + Dexamethasone: Patients With Triple Class Refractory Disease

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

Melphalan Flufenamide (Melflufen) + Dexamethasone: Full Analysis Set

4.27
months (Median)
95% Confidence Interval: 3.42 to 4.9

Melphalan Flufenamide (Melflufen) + Dexamethasone: Patients With Extramedullary Disease

2.89
months (Median)
95% Confidence Interval: 1.97 to 3.94

Melphalan Flufenamide (Melflufen) + Dexamethasone: Patients With Triple Class Refractory Disease

3.94
months (Median)
95% Confidence Interval: 3.09 to 4.67

Duration of Response

Time from first response to progression based on investigator assessment. See definitions of response and progression in ORR and PFS outcomes.

Melphalan Flufenamide (Melflufen) + Dexamethasone: Full Analysis Set

6.9
months (Median)
95% Confidence Interval: 4.4 to 10.38

Melphalan Flufenamide (Melflufen) + Dexamethasone: Patients With Extramedullary Disease

5.49
months (Median)
95% Confidence Interval: 2.1 to 12.71

Melphalan Flufenamide (Melflufen) + Dexamethasone: Patients With Triple Class Refractory Disease

7.46
months (Median)
95% Confidence Interval: 4.24 to 10.38

Overall Survival

Time from start of treatment to death

Melphalan Flufenamide (Melflufen) + Dexamethasone: Full Analysis Set

11.79
months (Median)
95% Confidence Interval: 9.53 to 14.55

Melphalan Flufenamide (Melflufen) + Dexamethasone: Patients With Extramedullary Disease

6.44
months (Median)
95% Confidence Interval: 5.06 to 9.66

Melphalan Flufenamide (Melflufen) + Dexamethasone: Patients With Triple Class Refractory Disease

10.12
months (Median)
95% Confidence Interval: 7.2 to 12.29

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.

Melphalan Flufenamide (Melflufen) + Dexamethasone: Full Analysis Set

Baseline value

75.5
units on a scale (Mean)
Standard Deviation: 13.2

Cycle 2 Day 1 Change from baseline

0.2
units on a scale (Mean)
Standard Deviation: 11.9

Cycle 4 Day 1 Change from baseline

-2.6
units on a scale (Mean)
Standard Deviation: 12.8

Cycle 6 Day 1 Change from baseline

-3.3
units on a scale (Mean)
Standard Deviation: 11.5

Cycle 8 Day 1 Change from baseline

-7.5
units on a scale (Mean)
Standard Deviation: 10.6

Melphalan Flufenamide (Melflufen) + Dexamethasone: Patients With Triple Class Refractory Disease

Baseline value

74.9
units on a scale (Mean)
Standard Deviation: 13.0

Cycle 2 Day 1 Change from baseline

74.8
units on a scale (Mean)
Standard Deviation: 13.7

Cycle 4 Day 1 Change from baseline

76.9
units on a scale (Mean)
Standard Deviation: 11.9

Cycle 6 Day 1 Change from baseline

73.2
units on a scale (Mean)
Standard Deviation: 12.6

Cycle 8 Day 1 Change from baseline

71.3
units on a scale (Mean)
Standard Deviation: 11.3

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.

Melphalan Flufenamide (Melflufen) + Dexamethasone: Full Analysis Set

Baseline value

0.6748
Change in composite scale score (Mean)
Standard Deviation: 0.2243

Cycle 2 Day 1 Change from baseline

-0.0228
Change in composite scale score (Mean)
Standard Deviation: 0.1848

Cycle 4 Day 1 Change from baseline

-0.0169
Change in composite scale score (Mean)
Standard Deviation: 0.2187

Cycle 6 Day 1 Change from baseline

-0.0786
Change in composite scale score (Mean)
Standard Deviation: 0.3049

Cycle 8 Day 1 Change from baseline

-0.1461
Change in composite scale score (Mean)
Standard Deviation: 0.2320

End of Treatment Change from baseline

-0.0014
Change in composite scale score (Mean)
Standard Deviation: 0.2594

Melphalan Flufenamide (Melflufen) + Dexamethasone: Patients With Triple Class Refractory Disease

Baseline value

0.6803
Change in composite scale score (Mean)
Standard Deviation: 0.2086

Cycle 2 Day 1 Change from baseline

-0.0502
Change in composite scale score (Mean)
Standard Deviation: 0.1846

Cycle 4 Day 1 Change from baseline

0.0038
Change in composite scale score (Mean)
Standard Deviation: 0.1919

Cycle 6 Day 1 Change from baseline

-0.1486
Change in composite scale score (Mean)
Standard Deviation: 0.3309

Cycle 8 Day 1 Change from baseline

-0.2174
Change in composite scale score (Mean)
Standard Deviation: 0.2464

End of Treatment Change from baseline

0.0124
Change in composite scale score (Mean)
Standard Deviation: 0.2552

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.

Melphalan Flufenamide (Melflufen) + Dexamethasone: Full Analysis Set

Melphalan Flufenamide (Melflufen) + Dexamethasone: Patients With Extramedullary Disease

Melphalan Flufenamide (Melflufen) + Dexamethasone: Patients With Triple Class Refractory Disease

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).

Melphalan Flufenamide (Melflufen) + Dexamethasone: Full Analysis Set

2.1
months (Median)
Full Range: 1.0 to 15.3

Melphalan Flufenamide (Melflufen) + Dexamethasone: Patients With Triple Class Refractory Disease

2.1
months (Median)
Full Range: 1.0 to 15.3

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.

Melphalan Flufenamide (Melflufen) + Dexamethasone: Full Analysis Set

4.4
months (Median)
95% Confidence Interval: 3.71 to 5.32

Melphalan Flufenamide (Melflufen) + Dexamethasone: Patients With Triple Class Refractory Disease

4.11
months (Median)
95% Confidence Interval: 3.32 to 4.86

Age, Continuous

64.7
years (Mean)
Standard Deviation: 9.63

Extramedullary disease at study entry

55
Participants

Time since initial diagnosis

7.0
years (Mean)
Standard Deviation: 3.46

Weight

74.3
kilograms (Mean)
Standard Deviation: 17.41

Age, Categorical

Cytogenetic risk group based on FISH at study entry

ECOG Performance Status

Ethnicity (NIH/OMB)

Heavy-light chain combination at study entry

International Staging System (ISS)

Race (NIH/OMB)

Region of Enrollment

Sex: Female, Male

Type of measurable disease at baseline

Overall Study

Melphalan Flufenamide (Melflufen) + Dexamethasone: Full Analysis Set