Clinical Pharmacology for Sarclisa
Mechanism Of Action
Isatuximab-irfc is an IgG1-derived monoclonal antibody that binds to CD38 expressed on the surface of hematopoietic and tumor cells, including multiple myeloma cells. Isatuximab-irfc induces apoptosis of tumor cells and activation of immune effector mechanisms including antibody-dependent cell-mediated cytotoxicity (ADCC), antibody-dependent cellular phagocytosis (ADCP), and complement dependent cytotoxicity (CDC). Isatuximab-irfc inhibits the ADP-ribosyl cyclase activity of CD38. Isatuximab-irfc can activate natural killer (NK) cells in the absence of CD38-positive target tumor cells and suppresses CD38-positive T-regulatory cells. The combination of isatuximab-irfc and pomalidomide enhanced ADCC activity and direct tumor cell killing compared to that of isatuximab-irfc alone in vitro, and enhanced antitumor activity compared to the activity of isatuximab-irfc or pomalidomide alone in a human multiple myeloma xenograft model.
Pharmacodynamics
In multiple myeloma patients treated with SARCLISA combined with pomalidomide and dexamethasone, a decrease in absolute counts of total NK cells (including inflammatory CD16+ low CD56+ bright and cytotoxic CD16+ bright CD56+ dim NK cells) and CD19+ B cells was observed in peripheral blood.
Cardiac Electrophysiology
Up to 2 times the approved recommended dose, SARCLISA does not prolong the QT interval to any clinically relevant extent.
A relationship between isatuximab-irfc exposure and overall response rate and progression-free survival was observed.
No apparent relationship was observed between an increase of isatuximab-irfc exposure and adverse reactions.
Pharmacokinetics
Following administration of isatuximab-irfc in combination with pomalidomide and dexamethasone at the recommended dose and schedule, the steady-state mean (CV%) predicted maximum plasma concentration (Cmax) and area under the plasma concentration-time curve (AUC) of isatuximab-irfc were 351 μg/mL (36.0%) and 72,600 μg•h/mL (51.7%), respectively.
Following administration of isatuximab-irfc in combination with carfilzomib and dexamethasone at the recommended dose and schedule, the steady state mean (CV%) predicted Cmax and AUC of isatuximab-irfc were 655 μg/mL (30.8%) and 159,000 μg•h/mL (37.1%), respectively.
The median time to reach steady state of isatuximab-irfc was 18 weeks with a 3.1-fold accumulation.
Following administration of isatuximab-irfc in combination with bortezomib, lenalidomide, and dexamethasone at the recommended dose and schedule, the mean (CV%) predicted Cmax and AUC of isatuximab-irfc after the dose on Week 21 were 496 μg/mL (25.6%) and 120,000 μg•h/mL (28.9%), respectively. The geometric mean (CV%) of accumulation ratio between steady state AUC and AUC after the dose on Week 21 is predicted to be 1.4 (35.8%). Isatuximab-irfc AUC increases in a greater than dose proportional manner over a dosage range from 1 mg/kg to 20 mg/kg (0.1 to 2 times the approved recommended dosage) every 2 weeks. Isatuximab-irfc AUC increases proportionally over a dosage range from 5 mg/kg to 20 mg/kg (0.5 to 2 times the approved recommended dosage) every week for 4 weeks followed by every 2 weeks.
Distribution
The mean (CV%) predicted total volume of distribution of isatuximab-irfc is of 8.13 L (26.2%).
Metabolism
Isatuximab-irfc is expected to be metabolized into small peptides by catabolic pathways.
Elimination
Isatuximab-irfc total clearance decreased with increasing dose and with multiple doses. At steady state, the near elimination (≥99%) of isatuximab-irfc from plasma after the last dose is predicted to occur in approximately 2 months. The elimination of isatuximab-irfc was similar when given as a single agent or as combination therapy.
Specific Populations
The following factors have no clinically meaningful effect on the exposure of isatuximabirfc: age (36 to 85 years, 70 patients were ≥75 years old), sex, renal impairment including patients with End-Stage Renal Disease (ESRD) or on dialysis (eGFR <90 mL/min/1.73 m ), and mild hepatic impairment (total bilirubin ≤ upper limit of normal [ULN] and aspartate aminotransferase [AST] >ULN, or total bilirubin >1 to 1.5 x ULN and any AST). The effect of moderate (total bilirubin >1.5 to 3 x ULN and any AST) and severe (total bilirubin >3 x ULN and any AST) hepatic impairment on isatuximab-irfc pharmacokinetics is unknown.
No dose adjustments are recommended in these specific patient populations.
Body Weight
The clearance of isatuximab-irfc increased with increasing body weight.
Race
White (n=377, 79%) or Asian (n=25, 5%) race have no clinically meaningful effect on the exposure of isatuximab-irfc. The effect of Black (n=18, 4%) race on the exposure of isatuximabÂirfc is unknown.
Immunogenicity
The observed incidence of anti-drug antibodies is highly dependent on the sensitivity and specificity of the assay. Differences in assay methods preclude meaningful comparisons of the incidence of anti-drug antibodies in the studies described below with the incidence of anti-drug antibodies in other studies, including those of isatuximab-irfc or of other isatuximab products.
Overall, across 9 clinical studies in relapsed and/or refractory multiple myeloma (RRMM) with SARCLISA single-agent and combination therapies including ICARIA-MM and IKEMA (N=1023), the incidence of treatment emergent anti-drug antibodies (ADAs) was <2%. In ICARIA-MM and IKEMA, no patients with RRMM tested positive for ADA. Therefore, the neutralizing ADA status was not determined. In RRMM, no effect of ADAs was observed on the pharmacokinetics, safety, or efficacy of SARCLISA.
In IMROZ, out of the 263 patients with NDMM treated with SARCLISA in combination with bortezomib, lenalidomide, and dexamethasone, 253 were evaluable for the presence of ADA, 22 patients (8.7%) tested positive for treatment-emergent ADAs, with 21 patients considered to have a transient ADA response and 1 considered to have an indeterminate ADA response. Among these 22 ADA-positive patients, 13 (5.9%) had neutralizing antibodies. In IMROZ, a trend to lower exposure was observed in ADA-positive patients, which was considered not clinically relevant. In patients with ADA-positive status to SARCLISA, including those with neutralizing antibodies, no meaningful impact of ADAs on safety or efficacy of SARCLISA was observed.
Clinical Studies
Relapsed and/or Refractory Multiple Myeloma
ICARIA-MM
The efficacy and safety of SARCLISA in combination with pomalidomide and dexamethasone (Isa-Pd) were evaluated in ICARIA-MM (NCT02990338), a multicenter, multinational, randomized, open-label, 2-arm, phase 3 study in patients with relapsed and/or refractory multiple myeloma. Patients had received at least two prior therapies including lenalidomide and a proteasome inhibitor. Patients were eligible for inclusion if they had an Eastern Cooperative Oncology Group (ECOG) status of 0-2, platelets ≥75,000 cells/mm³, absolute neutrophil count ≥1 x 109/L, creatinine clearance ≥30 mL/min/1.73 m² (MDRD formula), AST ≤3 x ULN, and ALT ≤3 x ULN.
A total of 307 patients were randomized in a 1:1 ratio to receive either SARCLISA in combination with pomalidomide and dexamethasone (Isa-Pd, 154 patients) or pomalidomide and dexamethasone (Pd, 153 patients). Treatment was administered in both groups in 28-day cycles until disease progression or unacceptable toxicity. SARCLISA 10 mg/kg was administered as an intravenous infusion weekly in the first cycle and every two weeks thereafter. Pomalidomide 4 mg was taken orally once daily from day 1 to day 21 of each 28-day cycle. Dexamethasone (orally or intravenously) 40 mg (20 mg for patients ≥75 years of age) was given on days 1, 8, 15, and 22 for each 28-day cycle.
Overall, demographic and disease characteristics at baseline were similar between the two treatment groups. The median patient age was 67 years (range 36-86), 20% of patients were ≥75 years; 79% of patients were White, 12% Asian, and 1% Black or African American; 10% of patients entered the study with a history of COPD or asthma. The proportion of patients with renal impairment (creatinine clearance <60 mL/min/1.73 m²) was 34%. The International Staging System (ISS) stage at study entry was I in 37%, II in 36% and III in 25% of patients. Overall, 20% of patients had high-risk chromosomal abnormalities at study entry; del(17p), t(4;14) and t(14;16) were present in 12%, 8% and 2% of patients, respectively.
The median number of prior lines of therapy was 3 (range 2-11). All patients received a prior proteasome inhibitor, all patients received prior lenalidomide, and 56% of patients received prior stem cell transplantation; the majority of patients (93%) were refractory to lenalidomide, 76% to a proteasome inhibitor, and 73% to both an immunomodulator and a proteasome inhibitor.
The median duration of treatment was 41 weeks for Isa-Pd group compared to 24 weeks for Pd group.
The efficacy of SARCLISA was based upon progression-free survival (PFS). PFS results were assessed by an Independent Response Committee based on central laboratory data for M-protein and central radiologic imaging review using the International Myeloma Working Group (IMWG) criteria. The improvement in PFS represented a 40% reduction in the risk of disease progression or death in patients treated with Isa-Pd.
Efficacy results are presented in Table 10 and Kaplan-Meier curve for PFS is provided in Figure 1.
Table 10: Efficacy of SARCLISA in Combination with Pomalidomide and Dexamethasone versus Pomalidomide and Dexamethasone in the Treatment of Multiple Myeloma (ICARIA-MM)
| Endpoint |
SARCLISA + Pomalidomide + Dexamethasone
N=154 |
Pomalidomide + Dexamethasone
N=153 |
| Progression-Free Survival |
| Median (months) [95% CI] |
11.53
[8.94-13.9] |
6.47
[4.47-8.28] |
| Hazard ratioa [95% CI] |
0.596 [0.44-0.81] |
| p-valuea (stratified log-rank test) |
0.0010 |
| Overall Response Rateb Responders (sCR+CR+VGPR+PR) n (%) [95% CI]c |
93 (60.4)
[52.2-68.2] |
54 (35.3)
[27.8-43.4] |
| p-value (stratified Cochran-Mantel-Haenszel)a |
<0.0001 |
| Stringent Complete Response (sCR) + Complete Response (CR) n (%) |
7 (4.5) |
3 (2) |
| Very Good Partial Response (VGPR) n (%) |
42 (27.3) |
10 (6.5) |
| Partial Response (PR) n (%) |
44 (28.6) |
41 (26.8) |
a Stratified-on age (<75 years versus ≥75 years) and number of previous lines of therapy (2 or 3 vs >3) according to IRT.
b sCR, CR, VGPR and PR were evaluated by the IRC using the IMWG response criteria.
c Estimated using Clopper-Pearson method. |
The median time to first response in responders was 35 days in the Isa-Pd group versus 58 days in the Pd group. The median duration of response was 13.3 months (95% CI: 10.6-NR) in the Isa-Pd group versus 11.1 months (95% CI: 8.5-NR) in the Pd group. At a median follow-up time of 52.4 months, final median overall survival was 24.6 months in the Isa-Pd group and 17.7 months in the Pd group (HR=0.776; 95% CI: 0.594 to 1.015).
Figure 1: Kaplan-Meier Curves of PFS – ITT Population – ICARIA-MM (assessment by the IRC)
IKEMA
The efficacy and safety of SARCLISA in combination with carfilzomib and dexamethasone were evaluated in IKEMA (NCT03275285), a multicenter, multinational, randomized, open-label, 2Âarm, phase 3 study in patients with relapsed and/or refractory multiple myeloma. Patients had received one to three prior lines of therapy. Patients were eligible for inclusion if they had an ECOG status of 0-2, platelets ≥50,000 cells/mm³ , absolute neutrophil count ≥1 x 109/L, creatinine clearance ≥15 mL/min/1.73 m² (MDRD formula), AST ≤3 x ULN, and ALT ≤3 x ULN.
A total of 302 patients were randomized in a 3:2 ratio to receive either SARCLISA in combination with carfilzomib and dexamethasone (Isa-Kd, 179 patients) or carfilzomib and dexamethasone (Kd, 123 patients). Treatment was administered in both groups in 28-day cycles until disease progression or unacceptable toxicity. SARCLISA 10 mg/kg was administered as an intravenous infusion weekly in the first cycle and every two weeks thereafter. Carfilzomib was administered as an intravenous infusion at the dose of 20 mg/m² on days 1 and 2; 56 mg/m² on days 8, 9, 15, and 16 of cycle 1; and at the dose of 56 mg/m² on days 1, 2, 8, 9, 15, and 16 for subsequent cycles of each 28-day cycle. Dexamethasone (intravenously on the days of isatuximab-irfc and/or carfilzomib infusions, and orally on the other days) 20 mg was given on days 1, 2, 8, 9, 15, 16, 22, and 23 for each 28-day cycle. On the days where both SARCLISA and carfilzomib were administered, dexamethasone was administered first, followed by SARCLISA infusion, then followed by carfilzomib infusion.
Overall, demographic and disease characteristics at baseline were similar between the two treatment groups. The median patient age was 64 years (range 33-90), 9% of patients were ≥75 years, 71% were White, 17% Asian, and 3% Black or African American. The proportion of patients with renal impairment (eGFR<60 mL/min/1.73 m²) was 24% in the Isa-Kd group versus 15% in the Kd group. The International Staging System (ISS) stage at study entry was I in 53%, II in 31%, and III in 15% of patients. Overall, 24% of patients had high-risk chromosomal abnormalities at study entry; del(17p), t(4;14), t(14;16) were present in 11%, 14%, and 2% of patients, respectively. In addition, gain(1q21) was present in 42% of patients.
The median number of prior lines of therapy was 2 (range 1-4) with 44% of patients who received 1 prior line of therapy. Overall, 90% of patients received prior proteasome inhibitors, 78% received prior immunomodulators (including 43% who received prior lenalidomide), and 61% received prior stem cell transplantation. Overall, 33% of patients were refractory to prior proteasome inhibitors, 45% were refractory to prior immunomodulators (including 33% refractory to lenalidomide), and 21% were refractory to both a proteasome inhibitor and an immunomodulator.
The median duration of treatment was 80 weeks for the Isa-Kd group compared to 61 weeks for the Kd group.
The efficacy of SARCLISA was based upon PFS. PFS results were assessed by an Independent Response Committee based on central laboratory data for M-protein and central radiologic imaging review using the IMWG criteria. The improvement in PFS represented a 45% reduction in the risk of disease progression or death in patients treated with Isa-Kd compared to patients treated with Kd.
Efficacy results are presented in Table 11 and Kaplan-Meier curves for PFS are provided in Figure 2.
Table 11a,b: Efficacy of SARCLISA in Combination with Carfilzomib and Dexamethasone versus Carfilzomib and Dexamethasone in the Treatment of Multiple Myeloma (IKEMA)
| Endpoint |
SARCLISA + Carfilzomib + Dexamethasone
N=179 |
Carfilzomib + Dexamethasone
N=123 |
| Progression-Free Survivalc |
| Median (months) |
NR |
20.27 |
| [95% CI] |
[NR- NR] |
[15.77-NR1 |
| Hazard ratiod [95% CI] |
0.548 [0.366-0.8221 |
| p-value (stratified log-rank test)d |
0.0032 |
| Overall Response Ratee |
| Responders (sCR+CR+VGPR+PR) n (%) [95% CI]f |
155 (86.6) [80.7-91.21 |
102 (82.9) [75.1-89.11 |
| p-value (stratified Cochran-Mantel-Haenszel)d |
0.3859 |
| Complete Response (CR) n (%) |
71 (39.7) |
34 (27.6) |
| Very Good Partial Response (VGPR) n (%) |
59 (33) |
35 (28.5) |
| Partial Response (PR) n (%) |
25 (14) |
33 (26.8) |
NR: not reached. a Results are based on
a prespecified interim analysis.
b Median follow-up time 20.7 months.
c PFS results were assessed by the IRC based on central laboratory data for M-protein and central radiologic imaging review using the IMWG criteria. A comparison is considered statistically significant if the p-value is <0.008 (efficacy boundary).
d Stratified on number of previous lines of therapy (1 versus >1) and R-ISS (I or II versus III versus not classified) according to IRT.
e sCR, CR, VGPR, and PR were evaluated by the IRC using the IMWG response criteria.
f Estimated using Clopper-Pearson method. |
Figure 2: Kaplan-Meier Curves of PFS – ITT Population – IKEMA (assessment by the IRC)
At a median follow-up time of 44.0 months, final PFS analysis showed a median PFS of 41.7 months for Isa-Kd group compared to 20.8 months for Kd group, with a hazard ratio of 0.594 (95.4% CI: 0.424 to 0.832). Final complete response, determined using a FDA-cleared isatuximab-irfc-specific IFE assay [see DRUG INTERACTIONS], was 44.1% in Isa-Kd group compared to 28.5% in Kd group.
At a median follow-up time of 57 months, median overall survival was not reached in the Isa-Kd group (95% CI: 52.172–NR) and was 50.6 months in Kd group (95% CI: 38.932– NR) (HR=0.855; 95% CI: 0.608–1.202).
Newly Diagnosed Multiple Myeloma
IMROZ
The efficacy of SARCLISA in combination with bortezomib, lenalidomide, and dexamethasone was evaluated in IMROZ (NCT03319667), a multicenter, international, randomized, open-label, 2-arm, phase 3 study in patients with newly diagnosed multiple myeloma who are not eligible for stem cell transplantation. Patients were eligible for inclusion if they had an Eastern Cooperative Oncology Group (ECOG) status of 0 or 1, platelets ≥70,000 cells/mm³, absolute neutrophil count ≥1 x 109/L, creatinine clearance ≥30 mL/min/1.73 m² (MDRD formula), AST ≤3 x ULN, and ALT ≤3 x ULN.
A total of 446 patients were randomized in a 3:2 ratio to receive either SARCLISA in combination with bortezomib, lenalidomide, and dexamethasone (Isa-VRd, 265 patients) or bortezomib, lenalidomide, and dexamethasone (VRd, 181 patients). Treatment was administered in both groups during 4 cycles of 42-days each for the induction period. After completion of cycle 4, patients entered the continuous treatment period starting from cycle 5, in which 28-day cycles were administered up to disease progression or unacceptable toxicity. During the continuous treatment period, patients of the Isa-VRd group received SARCLISA in combination with lenalidomide, and dexamethasone (Isa-Rd), and patients in the VRd group received lenalidomide, and dexamethasone (Rd). During the induction period (cycle 1 to 4, 42-day cycles), SARCLISA 10 mg/kg was administered as an intravenous infusion on day 1, 8, 15, 22, and 29, in the first cycle and on day 1, 15, and 29, from cycle 2 to 4. Bortezomib was administered subcutaneously at the dose of 1.3 mg/m² on days 1, 4, 8, 11, 22, 25, 29, and 32 of each cycle. Lenalidomide was administered orally at the dose of 25 mg/day from day 1 to 14 and from day 22 to 35 of each cycle. Dexamethasone (intravenously on the days of SARCLISA infusions, and orally on the other days) 20 mg/day was given on days 1, 2, 4, 5, 8, 9, 11, 12, 15, 22, 23, 25, 26, 29, 30, 32, and 33 of each cycle. During the continuous treatment period (from cycle 5, 28-day cycles), SARCLISA 10 mg/kg was administered as an IV infusion on day 1 and 15 from cycle 5 to 17, and on day 1 from cycle 18. Lenalidomide was administered orally at the dose of 25 mg/day from day 1 to 21 of each cycle. Dexamethasone (intravenously on the days of SARCLISA infusions, and orally on the other days) 20 mg/day was given on days 1, 8, 15, and 22 of each cycle.
The median patient age was 72 years (range 55-80), 28% of patients were ≥75 years; 72% of patients were White, 11% Asian, and 0.9% Black or African American. The proportion of patients with renal impairment (eGFR<60 mL/min/1.73m²) was 29%. The Revised International Staging System (R-ISS) stage at study entry was I in 23%, II in 64%, and III in 10% of patients. Overall, 17% of patients had high-risk chromosomal abnormalities at study entry; del(17p), t(4;14), and t(14;16) were present in 5%, 9% and 2% of patients, respectively. In addition, 1q21+ was present in 37% of patients.
The efficacy of SARCLISA was established based upon progression-free survival (PFS). PFS results were assessed by an Independent Response Committee based on central laboratory data for M-protein and central radiologic imaging review using the International Myeloma Working Group (IMWG) criteria. The improvement in PFS represented a 40% reduction in the risk of disease progression or death in patients treated with Isa-VRd.
Efficacy results are presented in Table 12 and Kaplan-Meier curves for PFS are provided in Figure 3:
Table 12 : Efficacy Results of SARCLISA in combination with bortezomib, lenalidomide, and dexamethasone versus bortezomib, lenalidomide, and dexamethasone (IMROZ)
| Endpoint |
SARCLISA + bortezomib + lenalidomide + dexamethasone
N =265 |
Bortezomib + lenalidomide + dexamethasone
N = 181 |
| Progression-Free Survivala |
| Median (months) [95% CI] |
NR
[NR-NR] |
54.34
[45.21-NR] |
| Hazard ratio b [95% CI] |
0.60 [0.44-0.81] |
| p-value (Stratified Log-Rank test) bc |
0.0009 |
| Overall Response Rate ad |
| Responders (sCR+CR+VGPR+PR) N(%) [95% CI] e |
242 (91) [87-94] |
167 (92) [87-96] |
| Stringent Complete Response (sCR) N(%) |
29 (11) |
10 (6) |
| Complete Response (CR) N(%) |
169 (64) |
106 (59) |
| Very Good Partial Response (VGPR) N(%) |
38 (14) |
34 (19) |
| Partial Response (PR) N(%) |
6 (2.3) |
17 (9) |
| CR or better (sCR and CR) f N(%) [95% CI] e |
198 (75) [69-80] |
116 (64) [57-71] |
| p-value (Stratified Cochran-Mantel-Haenszel) b |
0.0160 |
| Minimal Residual Disease (MRD) |
| MRD negativity rate afgh N(%) [95% CI] e |
147 (55) [49-62] |
74 (41) [34-48] |
| p-value (Stratified Cochran-Mantel-Haenszel) b |
0.0026 |
| Number of patients with CR or better (sCR and CR) |
198 |
116 |
| MRD negativity rate in patients with CR or better gh N(%) [95% CI] |
147 (74) [68-80] |
74 (64) [54-73] |
|
NR: not reached.
Median follow-up time=60 months.
a Based on ITT population.
b Stratified by age (<70 years vs ≥70 years) and Revised International Staging System (R-ISS) stage (I or II vs. III or not classified) according to IRT.
c A comparison is considered statistically significant if the p-value is <0.0148.
d sCR, CR, VGPR, and PR were evaluated by the IRC using the IMWG response criteria.
e Estimated using Clopper-Pearson method.
f Other efficacy endpoints of CR and MRD negativity CR were tested hierarchically after PFS.
g Patients achieved both MRD negativity (threshold of 10-5) and response of CR or better.
h Based on a sensitivity level of 10-5 by the next-generation sequencing assay (clonoSEQ).
NR: not reached.
Median follow-up time=60 months.
|
Median overall survival was not reached for either treatment group. At a median follow-up time of 60 months, 26% of patients in the Isa-VRd group and 32.6% of patients in the VRd group had died (HR=0.78; 95% CI: 0.55 to 1.1).
Figure 3 : Kaplan-Meier Curves of PFS – ITT population – IMROZ