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Pharmacotherapeutic group: Antineoplastic agents, monoclonal antibodies. ATC code: L01XC23.
Mechanism of action
Elotuzumab is an immunostimulatory humanised, IgG1 monoclonal antibody that specifically targets the SLAMF7 (signaling lymphocyte activation molecule family member 7) protein. SLAMF7 is highly expressed on multiple myeloma cells independent of cytogenetic abnormalities. SLAMF7 is also expressed on natural killer cells, normal plasma cells, and other immune cells including some T cell subsets, monocytes, B cells, and pDCs (plasmacytoid dendritic cells), but is not detected on normal solid tissues or haematopoietic stem cells.Elotuzumab directly activates natural killer cells through both the SLAMF7 pathway and Fc receptors enhancing anti-myeloma activity in vitro. Elotuzumab also targets SLAMF7 on myeloma cells and facilitates the interaction with natural killer cells to mediate the killing of myeloma cells through antibody-dependent cellular cytotoxicity (ADCC). In nonclinical models, elotuzumab has demonstrated synergistic activity when combined with lenalidomide or bortezomib.
Clinical efficacy and safety
Two randomised, open-label studies were conducted to evaluate the efficacy and safety of Empliciti (elotuzumab) in adult patients with multiple myeloma who have received one or more prior therapies.Study 1 provided the pivotal data for the indication for Empliciti in combination with lenalidomide and dexamethasone.
Study 1
A randomised, open-label study was conducted to evaluate the efficacy and safety of Empliciti in combination with lenalidomide and dexamethasone in patients with multiple myeloma who have received one to three prior therapies. All patients had documented progression following their most recent therapy. Patients who were refractory to lenalidomide were excluded and 6% of patients had prior lenalidomide treatment. Patients had to recover after transplant for a minimum of 12 weeks from autologous stem cell transplant (SCT), and 16 weeks from allogeneic SCT. Patients with cardiac amyloidosis or plasma cell leukemia were excluded from this study.Eligible patients were randomised in a 1:1 ratio to receive either Empliciti in combination with lenalidomide and dexamethasone or lenalidomide and dexamethasone. Treatment was administered in 4-week cycles until disease progression or unacceptable toxicity. Elotuzumab 10 mg/kg was administered intravenously each week for the first 2 cycles and every 2 weeks thereafter. Prior to Empliciti infusion, dexamethasone was administered as a divided dose: an oral dose of 28 mg and an intravenous dose of 8 mg. In the control group and on weeks without Empliciti, dexamethasone 40 mg was administered as a single oral dose weekly. Lenalidomide 25 mg was taken orally once daily for the first 3 weeks of each cycle. Assessment of tumour response was conducted every 4 weeks.A total of 646 patients were randomised to receive treatment: 321 to Empliciti in combination with lenalidomide and dexamethasone and 325 to lenalidomide and dexamethasone.Demographics and baseline characteristics were well balanced between treatment arms. The median age was 66 years (range 37 to 91); 57% of patients were older than 65 years; 60% of patients were male; Whites comprised 84% of the study population, Asians 10%, and blacks 4%. The International Staging System (ISS) Stage was I in 43%, II in 32% and III in 21% of patients. The high risk cytogenetic categories of del17p and t(4;14) were present in 32% and 9% of patients, respectively. The median number of prior therapies was 2. Thirty-five percent (35%) of patients were refractory (progression during or within 60 days of last therapy) and 65% were relapsed (progression after 60 days of last therapy). Prior therapies included: stem cell transplant (55%), bortezomib (70%) melphalan (65%), thalidomide (48%), and lenalidomide (6%).The primary endpoints of this study, progression-free survival (PFS), as assessed by hazard ratio, and overall response rate (ORR) were determined based on assessments made by a blinded Independent Review Committee. Efficacy results are presented in Table 5 and Figure 1. The median number of treatment cycles was 19 for the Empliciti arm and 14 for the comparator arm.
| Table 5: Efficacy results for Study 1
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| Empliciti + Lenalidomide/ Dexamethasone N = 321
| Lenalidomide/ Dexamethasone N = 325
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| PFS (ITT)
|
|
| Hazard Ratio [97.61% CI]
| 0.68 [0.55, 0.85]
| | Stratified log-rank test p-valuea
| 0.0001
| | 1-Year PFS rate (%) [95% CI]
| 68 [63, 73]
| 56 [50, 61]
| | 2-Year PFS rate (%) [95% CI]
| 39 [34, 45]
| 26 [21, 31]
| | 3-Year PFS rateb (%) [95% CI]
| 23 [18, 28]
| 15 [10, 20]
| | Median PFS in months [95% CI]
| 18.5 [16.5, 21.4]
| 14.3 [12.0, 16.0]
| | Response
|
| | Overall Response (ORR)c n (%) [95% CI]
| 252 (78.5) [73.6, 82.9]
| 213 (65.5) [60.1, 70.7]
| | p-valued
| 0.0002
| | Complete Response (CR + sCR)e n (%)
| 14 (4.4)f
| 24 (7.4)
| | Very Good Partial Response (VGPR) n (%)
| 91 (28.3)
| 67 (20.6)
| | Partial Response (RR/PR) n (%)
| 147 (45.8)
| 122 (37.5)
| | Combined Responses (CR+sCR+VGPR) n (%)
| 105 (32.7)
| 91 (28.0)
| | Overall Survivalg
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|
| | Hazard Ratio [95% CI]
| 0.77 [0.61, 0.97]
| | Stratified log-rank test p-value
| 0.0257h
| | Median OS in months [95% CI]
| 43.7 [40.34, NE]
| 39.6 [33.25,NE]
| a p-value based on the log-rank test stratified by B2 microglobulins (<3.5 mg/L versus ≥ 3.5 mg/L), number of prior lines of therapy (1 versus 2 or 3), and prior immunomodulatory therapy (no versus prior thalidomide only versus other).b A pre-specified analysis for 3-year PFS rate was performed based on a minimum follow-up time of 33 months.c European Group for Blood and Marrow Transplantation (EBMT) criteria.d p-value based on the Cochran-Mantel-Haenszel chi-square test stratified by B2 microglobulins (<3.5 mg/L versus ≥ 3.5 mg/L), number of prior lines of therapy (1 versus 2 or 3), and prior immunomodulatory therapy (no versus prior thalidomide only versus other).e Complete response (CR) + stringent complete response (sCR).f Complete response rates in Empliciti group may be underestimated due to interference of elotuzumab monoclonal antibody with immunofixation assay and serum protein electrophoresis assay.g A pre-specified interim analysis for OS was performed based on a minimum follow-up time of 35.4 months.h The interim OS analysis did not meet the protocol-specified early stopping boundary for OS (p ≤ 0.014).
Figure 1: Progression free survival
| Progression free survival (Months)
| | Number of subjects at risk
| | E-Ld
| 321
| 282
| 240
| 206
| 164
| 133
| 87
| 43
| 12
| 1
| | Ld
| 325
| 262
| 204
| 168
| 130
| 97
| 53
| 24
| 7
|
| Improvements observed in PFS were consistent across subsets regardless of age (< 65 versus ≥ 65), risk status, presence or absence of cytogenetic categories del17p or t(4;14), ISS stage, number of prior therapies, prior immunomodulatory exposure, prior bortezomib exposure, relapsed or refractory status or renal function as shown in Table 6.
| Table 6: Efficacy results for subsets
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| E-Ld N = 321
| Ld N = 325
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| | Subset description
| Median PFS (months) [95% CI]
| Median PFS (months) [95% CI]
| HR [95% CI]
| | Age
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| | < 65 years
| 19.4 [15.9, 23.1]
| 15.7 [11.2, 18.5]
| 0.74 [0.55, 1.00]
| | ≥ 65 years
| 18.5 [15.7, 22.2]
| 12.9 [10.9, 14.9]
| 0.64 [0.50, 0.82]
| | Risk factors
|
|
|
| | High risk
| 14.8 [9.1, 19.6]
| 7.2 [5.6, 11.2]
| 0.63 [0.41, 0.95]
| | Standard risk
| 19.4 [16.5, 22.7]
| 16.4 [13.9, 18.5]
| 0.75 [0.59, 0.94]
| | Cytogenetic category
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|
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| | Presence of del17p
| 19.6 [15.8, NE]
| 14.9 [10.6, 17.5]
| 0.65 [0.45, 0.93]
| | Absence of del17p
| 18.5 [15.8, 22.1]
| 13.9 [11.1, 16.4]
| 0.68 [0.54, 0.86]
| | Presence of t(4;14)
| 15.8 [8.4, 18.4]
| 5.5 [3.1, 10.3]
| 0.55 [0.32, 0.98]
| | Absence of t(4;14)
| 19.6 [17.0, 23.0]
| 14.9 [12.4, 17.1]
| 0.68 [0.55, 0.84]
| | ISS Stage
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|
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| | I
| 22.2 [17.8, 31.3]
| 16.4 [14.5, 18.6]
| 0.61 [0.45, 0.83]
| | II
| 15.9 [9.5, 23.1]
| 12.9 [11.1, 18.5]
| 0.83 [0.60, 1.16]
| | III
| 14.0 [9.3, 17.3]
| 7.4 [5.6, 11.7]
| 0.70 [0.48, 1.04]
| | Prior therapies
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|
|
| | Lines of prior therapy = 1
| 18.5 [15.8, 20.7]
| 14.5 [10.9, 17.5]
| 0.71 [0.54, 0.94]
| | Lines of prior therapy = 2 or 3
| 18.5 [15.9, 23.9]
| 14.0 [11.1, 15.7]
| 0.65 [0.50, 0.85]
| | Prior thalidomide exposure
| 18.4 [14.1, 23.1]
| 12.3 [9.3, 14.9]
| 0.61 [0.46, 0.80]
| | No prior immunomodulatory exposure
| 18.9 [15.8, 22.2]
| 17.5 [13.0, 20.0]
| 0.78 [0.59, 1.04]
| | Prior bortezomib exposure
| 17.8 [15.8, 20.3]
| 12.3 [10.2, 14.9]
| 0.67 [0.53, 0.84]
| | No prior bortezomib exposure
| 21.4 [16.6, NE]
| 17.5 [13.1, 21.3]
| 0.70 [0.48, 1.00]
| | Response to therapy
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|
|
| | Relapsed
| 19.4 [16.6, 22.2]
| 16.6 [13.0, 18.9]
| 0.75 [0.59, 0.96]
| | Refractory
| 16.6 [14.5, 23.3]
| 10.4 [6.6, 13.3]
| 0.55 [0.40, 0.76]
| | Renal function
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|
|
| | Baseline CrCl < 60 mL/min
| 18.5 [14.8, 23.3]
| 11.7 [7.5, 17.4]
| 0.56 [0.39, 0.80]
| | Baseline CrCl ≥ 60 mL/min
| 18.5 [15.9, 22.2]
| 14.9 [12.1, 16.7]
| 0.72 [0.57, 0.90]
| The 1-, 2- and 3-year rates of overall survival for Empliciti in combination with lenalidomide and dexamethasone treatment were 91%, 73%, and 60% respectively, compared with 83%, 69%, and 53% respectively, for lenalidomide and dexamethasone treatment (See Figure 2).
Figure 2: Overall survival
| Overall survival (Months)
| | Number of subjects at risk
| | E-Ld
| 321
| 308
| 296
| 283
| 264
| 242
| 224
| 210
| 191
| 152
| 84
| 23
| 5
| | Ld
| 325
| 298
| 278
| 255
| 237
| 222
| 208
| 193
| 174
| 134
| 69
| 22
| 3
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Paediatric population
The European Medicines Agency has waived the obligation to submit the results of studies in all subsets of the paediatric population in treatment of multiple myeloma (see section 4.2 for information on paediatric use).
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