Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.
The safety of ZENBEXUS in combination with daratumumab and hyaluronidase-fihj and dexamethasone was evaluated in EXCALIBER-RRMM, a two-stage, phase 3, randomized, multicenter open-label study in patients with relapsed or refractory multiple myeloma (RRMM) after 1 or 2 prior lines of therapy [see Clinical Studies (14)]. Patients were randomized to receive ZENBEXUS (at 1 of 3 dose levels) in combination with daratumumab and hyaluronidase-fihj and dexamethasone or daratumumab and hyaluronidase-fihj, bortezomib and dexamethasone (DVd) in stage 1, and ZENBEXUS 1 mg in combination with daratumumab and hyaluronidase-fihj and dexamethasone (IberDd) or DVd in stage 2. The MRD Primary Analysis Group included the first 420 patients randomized to ZENBEXUS 1 mg in combination with Dd (N=207) or DVd (N=213) in stage 1 and stage 2. Safety was assessed in patients in the MRD Primary Analysis Group who received at least one dose of the study drug (IberDd: N=204; DVd: N=204). Among patients who received ZENBEXUS, 86% were exposed for 6 months or longer and 73% were exposed for greater than one year.
Serious adverse reactions occurred in 58.3% of patients who received ZENBEXUS. Serious adverse reactions in ≥2% of patients included pneumonia (26%), upper respiratory tract infection (6.4%), second primary malignancy (5.9%), neutropenia (4.9%), febrile neutropenia (3.9%), COVID-19 (4.4%), and sepsis (2.9%). Fatal adverse reactions occurred in 10 patients (4.9%) who received ZENBEXUS. Sepsis (1.5%) was the only fatal drug reaction that occurred in more than 1 patient. The following fatal adverse reactions occurred in one patient each: listeria encephalitis, influenza, lung adenocarcinoma, cardiac arrest, large intestine perforation, metabolic acidosis, and respiratory failure.
Permanent discontinuation of ZENBEXUS due to an adverse reaction occurred in 7.8% of patients. The most frequent adverse reaction which resulted in permanent ZENBEXUS discontinuation was neutropenia (1%).
Dosage interruption of ZENBEXUS due to an adverse reaction occurred in 84% of patients. Adverse reactions which required dosage interruption in >10% of patients included neutropenia, upper respiratory tract infection, pneumonia and COVID-19.
Dosage reductions of ZENBEXUS due to an adverse reaction occurred in 29% of patients. Adverse reactions which required dose reductions in >2% of patients included neutropenia, fatigue, pneumonia, and sensory neuropathy.
The most common adverse reactions (≥20%) were upper respiratory tract infection, fatigue, musculoskeletal pain, pneumonia, diarrhea, motor dysfunction, rash, sleep disorder, hypogammaglobulinemia, COVID-19, and constipation.
The most common Grade 3 to 4 laboratory abnormalities (≥30%) were decreased neutrophils, decreased white blood cells, and decreased lymphocytes.
Tables 2 and 3 summarize adverse reactions and laboratory abnormalities, respectively, in the EXCALIBER-RRMM study.
Table 2: Adverse Reactions (≥10%) in Patients Who Received ZENBEXUS in Combination with Daratumumab and Hyaluronidase-fihj and Dexamethasone in EXCALIBER-RRMM| Adverse reactions were graded according to NCI CTCAE Version 5.0. |
Adverse Reaction | ZENBEXUS + Daratumumab and Hyaluronidase-fihj + Dexamethasone (IberDd) (n=204) | Daratumumab and Hyaluronidase-fihj + Bortezomib + Dexamethasone (DVd) (n=204) |
All Grades (%) | Grade 3 or 4 (%) | All Grades (%) | Grade 3 or 4 (%) |
Infections and infestations |
Upper respiratory tract infection Upper respiratory tract infection includes nasopharyngitis, pharyngitis, respiratory tract infection, sinusitis, and other related terms. | 54 Includes fatal adverse reaction: IberDd (n=1). | 6 | 52 | 6 |
Pneumonia Pneumonia includes atypical pneumonia, bacterial pneumonia, lower respiratory tract infection, lung consolidation, viral pneumonia and other related terms. | 34 | 25 | 17 | 10 |
COVID-19 Includes other related terms. | 23 | 3.9 | 16 | 2.9 |
General disorders and administration site conditions |
Fatigue | 36 | 3.4 | 33 | 2.5 |
Edema | 17 | 0.5 | 24 | 1 |
Pyrexia | 14 | 1 | 15 | 1 |
Musculoskeletal and connective tissue disorders |
Musculoskeletal pain | 35 | 1.5 | 33 | 2.9 |
Bone pain | 11 | 1 | 13 | 0.5 |
Gastrointestinal disorders |
Diarrhea | 33 | 4.9 | 36 | 6 |
Constipation | 20 | 0 | 22 | 1 |
Nausea | 14 | 0.5 | 6 | 0 |
Nervous system disorders |
Motor dysfunction Motor dysfunction includes ataxia, balance disorder, gait disturbance, muscle contracture, muscle spasms, muscular weakness, myopathy, paralysis, peripheral motor neuropathy and other related terms. | 26 | 1.5 | 17 | 2.5 |
Sensory neuropathy Sensory neuropathy includes anosmia, hypoesthesia, mononeuropathy, neuralgia, paresthesia, peripheral neuropathy, peripheral sensory neuropathy, polyneuropathy, radiculopathy and other related terms. | 19 | 4.4 | 53 | 6 |
Dizziness | 11 | 0 | 9 | 0.5 |
Skin and subcutaneous tissue disorders |
Rash | 26 | 1 | 15 | 0.5 |
Psychiatric disorders |
Sleep disorder Sleep disorder includes insomnia, restless legs syndrome, sleep disorder and other related terms. | 25 | 2.9 | 28 | 1.5 |
Immune system disorders |
Hypogammaglobulinemia Hypogammaglobulinemia includes hypogammaglobulinemia, hypoglobulinemia, and other related terms. | 24 | 1 | 12 | 0.5 |
Respiratory, thoracic and mediastinal disorders |
Cough | 18 | 0.5 | 14 | 0.5 |
Dyspnea | 10 | 0 | 9 | 1 |
Renal and urinary disorders |
Renal impairment | 11 | 3.4 | 8 | 3.9 |
Vascular disorders |
Hemorrhage Hemorrhage includes epistaxis, gastrointestinal hemorrhage, hematuria, injection site hemorrhage, rectal hemorrhage, subarachnoid hemorrhage, subdural hematoma and other related terms. | 10 | 1.5 | 9 | 2 |
Clinically relevant adverse reactions in <10% of patients who received ZENBEXUS (in combination with daratumumab and hyaluronidase-fihj and dexamethasone) included:
- Venous thromboembolic event (includes retinal vein occlusion, pulmonary embolism, deep vein thrombosis, embolism venous, post thrombotic syndrome, superficial vein thrombosis, and thrombophlebitis).
- Arterial thromboembolic event (includes myocardial infarction, stress cardiomyopathy, ischemic stroke, lacunar infarction, peripheral arterial occlusive disease).
- Second primary malignancy
- Febrile neutropenia
- Sepsis
- Hepatotoxicity
Table 3: Select Laboratory Abnormalities (≥30%) That Worsened from BaselineThe denominator used to calculate the rate varied from 201 to 204 for both IberDd and DVd arms based on the number of patients with a baseline value and at least one post-treatment value.
in Patients Who Received ZENBEXUS in EXCALIBER-RRMMLaboratory Abnormality | ZENBEXUS + Daratumumab and hyaluronidase-fihj + Dexamethasone (IberDd) | Daratumumab and hyaluronidase-fihj + Bortezomib + Dexamethasone (DVd) |
All Grades (%) | Grade 3 or 4 (%) | All Grades (%) | Grade 3 or 4 (%) |
Hematology |
Neutrophil count decreased | 97 | 77 | 48 | 11 |
White blood cell count decreased | 95 | 69 | 64 | 18 |
Lymphocytes count decreased | 91 | 62 | 81 | 51 |
Platelet count decreased | 62 | 9 | 92 | 46 |
Hemoglobin decreased | 58 | 6 | 63 | 6 |
Chemistry |
Blood calcium decreased | 44 | 2 | 28 | 1 |
Blood alkaline phosphatase increased | 33 | 0.5 | 26 | 0.5 |