The following clinically significant adverse reactions are described elsewhere in the labeling: Hypersensitivity Reactions Including Infusion-Associated Events [see Warnings and Precautions (5.1) ] The most common adverse events (incidence ≥20%) were pyrexia, chills, tachycardia, tachypnea, and vomiting. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Regeneron at 1-844-734-6643 or www.regeneron.com/contact or FDA AT 1-800-FDA-1088 or www.fda.gov/medwatch.
6.1Clinical Trials Experience
Because clinical trials are conducted under widely varying conditions, adverse reaction rates may not reflect the rates observed in practice. Overall, 382 adult and pediatric subjects with Orthoebolavirus zairense infection received INMAZEB in one clinical trial (the PALM trial) and as part of an expanded access program conducted in the Democratic Republic of Congo during a Orthoebolavirus zairense outbreak in 2018-2019.
In the PALM trial, the safety of INMAZEB was evaluated in a multi-center, open-label, randomized controlled trial, in which 154 subjects (115 adult subjects and 39 pediatric subjects) received INMAZEB [50 mg of atoltivimab, 50 mg of maftivimab, and 50 mg of odesivimab per kg (3 mL/kg)] intravenously as a single infusion and 168 subjects received an investigational control [see Clinical Studies (14) ] . All subjects received optimized standard of care treatment.
During the same outbreak, INMAZEB [50 mg of atoltivimab, 50 mg of maftivimab, and 50 mg of odesivimab per kg (3 mL/kg)] was given to 228 subjects (190 adult subjects and 38 pediatric subjects) in the expanded access program. The safety data described below is derived from the PALM trial. Table 4 summarizes adverse events that were reported during INMAZEB infusion. The evaluation of adverse events in subjects who received INMAZEB may have been confounded by the signs and symptoms of the underlying Orthoebolavirus zairense infection.
The most common adverse events reported in at least 20% of subjects who received INMAZEB were pyrexia (or elevation in fever), chills, tachycardia, tachypnea, and vomiting. The adverse event profile in adult and pediatric subjects treated with INMAZEB was similar. Table 4: Adverse Events That Occurred during INMAZEB Infusion in ≥10% of Adult and Pediatric Subjects in the PALM Trial Adverse Event Adverse events in this table were reported as preferred terms from a list of pre-defined or other adverse events that occurred on the day of infusion, and included signs and symptoms that occurred during or immediately after infusion INMAZEB (N=154) % Control Investigational therapy administered as three separate infusions (N=168) % Pyrexia (Elevation in fever) 54 58 Chills 39 33 Tachycardia 20 32 Tachypnea 19 28 Vomiting Adverse events that were not pre-specified 19 23 Hypotension 15 31 Diarrhea 11 18 Hypoxia 10 11 The following pre-specified symptoms, which were assessed on a daily basis while admitted to the treatment unit, were reported in 40% or more of subjects who received INMAZEB: diarrhea, pyrexia, and vomiting.
Evaluation of these symptoms may have been confounded by the underlying Orthoebolavirus zairense infection. Discontinuation and Infusion Rate Adjustments in the PALM Trial Approximately 99% of subjects who received INMAZEB in the PALM trial were able to complete their dose within three hours. Two subjects who received INMAZEB (1%) did not receive their complete infusion. One of the two subjects did not complete their INMAZEB infusion because of fever elevation [see Warnings and Precautions (5.1) ] .
Selected Laboratory Abnormalities in the PALM Trial Table 5 presents selected laboratory abnormalities (worsening to Grade 3 or 4 compared to baseline) for adult and pediatric subjects in the PALM trial. Table 5: Selected Grade 3 and 4 Laboratory Abnormalities, Worsened Grade from Baseline for Adult and Pediatric Subjects in the PALM Trial Laboratory Test Graded per Division of AIDS (DAIDS) v2.1 INMAZEB N=154 % Control N=168 % ULN = upper limit of normal Sodium, high ≥ 154 mmol/L 9 4 Sodium, low < 125 mmol/L 7 11 Potassium, high ≥ 6.5 mmol/L 13 12 Potassium, low < 2.5 mmol/L 9 8 Creatinine (mg/dL) ≥ 1.8 × ULN ULN for creatinine was 1.2 mg/dL.
Criterion for increase to ≥ 1.5 × from baseline was applied if the worsening grade was higher. 15 23 Alanine aminotransferase (U/L) ≥ 5 × ULN 10 14 Aspartate aminotransferase (U/L) ≥ 5 × ULN 21 18
6.2 Immunogenicity As with all therapeutic proteins, there is potential for immunogenicity. The detection of antibody formation is highly dependent on the sensitivity and specificity of the assay. Additionally, the observed incidence of antibody (including neutralizing antibody) positivity in an assay may be influenced by several factors including assay methodology, sample handling, timing of sample collection, concomitant medications, and underlying disease.
For these reasons, comparison of the incidence of antibodies in the study described below with the incidence of antibodies in other studies or to other atoltivimab, maftivimab, and odesivimab products may be misleading. The development of anti-atoltivimab, anti-maftivimab, and anti-odesivimab antibodies was evaluated in 24 healthy adults in a single dose, randomized, double-blind, placebo-controlled, dose escalation study.
Immunogenic responses against atoltivimab, maftivimab, and odesivimab were not detected at baseline or through 168 days post-dose in any subjects.
