As with all therapeutic proteins, there is the 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 studies described below with the incidence of antibodies in other studies or to other amivantamab products may be misleading.
In CHRYSALIS, 3 of the 286 (1%) patients who were treated with RYBREVANT and evaluable for the presence of anti-drug antibodies (ADA), tested positive for treatment-emergent anti-amivantamab-vmjw antibodies (one at 27 days, one at 59 days and one at 168 days after the first dose) with titers of 1:40 or less. There are insufficient data to evaluate the effect of ADA on the pharmacokinetics, safety, or efficacy of RYBREVANT.
Based on the mechanism of action and findings in animal models, RYBREVANT can cause fetal harm when administered to a pregnant woman. There are no available data on the use of RYBREVANT in pregnant women or animal data to assess the risk of RYBREVANT in pregnancy. Disruption or depletion of EGFR in animal models resulted in impairment of embryo-fetal development including effects on placental, lung, cardiac, skin, and neural development. The absence of EGFR or MET signaling has resulted in embryo lethality, malformations, and post-natal death in animals (see Data). Advise pregnant women of the potential risk to a fetus.
In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.
No animal studies have been conducted to evaluate the effects of amivantamab-vmjw on reproduction and fetal development; however, based on its mechanism of action, RYBREVANT can cause fetal harm or developmental anomalies. In mice, EGFR is critically important in reproductive and developmental processes including blastocyst implantation, placental development, and embryo-fetal/postnatal survival and development. Reduction or elimination of embryo-fetal or maternal EGFR signaling can prevent implantation, can cause embryo-fetal loss during various stages of gestation (through effects on placental development) and can cause developmental anomalies and early death in surviving fetuses. Adverse developmental outcomes were observed in multiple organs in embryos/neonates of mice with disrupted EGFR signaling. Similarly, knock out of MET or its ligand HGF was embryonic lethal due to severe defects in placental development, and fetuses displayed defects in muscle development in multiple organs. Human IgG1 is known to cross the placenta; therefore, amivantamab-vmjw has the potential to be transmitted from the mother to the developing fetus.
There are no data on the presence of amivantamab-vmjw in human milk on milk production, or its effects on the breastfed child. Because of the potential for serious adverse reactions from RYBREVANT in breast-fed infants, advise women not to breast-feed during treatment with RYBREVANT and for 3 months after the final dose.
RYBREVANT can cause fetal harm when administered to a pregnant woman [see Use in Specific Populations (8.1)].
Verify pregnancy status of females of reproductive potential prior to initiating RYBREVANT.
Advise females of reproductive potential to use effective contraception during treatment and for 3 months after the final dose of RYBREVANT.
The safety and efficacy of RYBREVANT have not been established in pediatric patients.
Of the 129 patients treated with RYBREVANT, 41% were 65 years of age or older, and 9% were 75 years of age or older. No clinically important differences in safety or efficacy were observed between patients who were ≥65 years of age and younger patients.
Amivantamab-vmjw is a low-fucose human immunoglobulin G1-based bispecific antibody directed against the EGF and MET receptors, produced by mammalian cell line (Chinese Hamster Ovary [CHO]) using recombinant DNA technology that has a molecular weight of approximately 148 kDa. RYBREVANT (amivantamab-vmjw) injection for intravenous infusion is a sterile, preservative-free, colorless to pale yellow solution in single-dose vials. The pH is 5.7.
Each RYBREVANT vial contains 350 mg (50 mg/mL) amivantamab-vmjw, EDTA disodium salt dihydrate (0.14 mg), L-histidine (2.3 mg), L-histidine hydrochloride monohydrate (8.6 mg), L-methionine (7 mg), polysorbate 80 (4.2 mg), sucrose (595 mg), and water for injection, USP.
Amivantamab-vmjw is a bispecific antibody that binds to the extracellular domains of EGFR and MET.
In in vitro and in vivo studies amivantamab-vmjw was able to disrupt EGFR and MET signaling functions through blocking ligand binding and, in exon 20 insertion mutation models, degradation of EGFR and MET. The presence of EGFR and MET on the surface of tumor cells also allows for targeting of these cells for destruction by immune effector cells, such as natural killer cells and macrophages, through antibody-dependent cellular cytotoxicity (ADCC) and trogocytosis mechanisms, respectively.
The exposure-response relationship and time-course of pharmacodynamic response of amivantamab-vmjw have not been fully characterized in patients with NSCLC with EGFR exon 20 insertion mutations.
Amivantamab-vmjw exposures increased proportionally over a dosage range from 350 to 1750 mg (0.25 to 1.25 times the maximum approved recommended dosage). Steady state of amivantamab-vmjw concentrations was achieved by the 9th infusion. The accumulation ratio at steady state was 2.4.
The amivantamab-vmjw mean (± SD) volume of distribution is 5.13 (± 1.78) L.
The mean (± SD) clearance of amivantamab-vmjw is 360 (± 144) mL/day and the terminal half-life is 11.3 (± 4.53) days.
No clinically meaningful differences in the pharmacokinetics of amivantamab-vmjw were observed based on age (range: 32–87 years), sex, race, creatinine clearance (CLcr 29 to 276 mL/min), or mild hepatic impairment [(total bilirubin ≤ ULN and AST > ULN) or (ULN < total bilirubin ≤ 1.5 times ULN)]. The pharmacokinetics of amivantamab-vmjw have not been studied in patients with severe renal impairment (CLcr 15 to 29 mL/min) or patients with moderate (total bilirubin 1.5 to 3 times ULN) to severe (total bilirubin > 3 times ULN) hepatic impairment.
Increases in body weight increased the volume of distribution and clearance of amivantamab-vmjw. Amivantamab-vmjw exposures are 30–40% lower in patients who weighed ≥ 80 kg compared to patients with body weight < 80 kg at the same dose. Exposures of amivantamab-vmjw were comparable between patients who weighed < 80 kg and received 1050 mg dose and patients who weighed ≥ 80 kg and received 1400 mg dose.
No studies have been performed to assess the potential of amivantamab-vmjw for carcinogenicity or genotoxicity. Fertility studies have not been performed to evaluate the potential effects of amivantamab-vmjw. In 6-week and 3-month repeat-dose toxicology studies in monkeys, there were no notable effects in the male and female reproductive organs.
The efficacy of RYBREVANT was evaluated in patients with locally advanced or metastatic NSCLC with EGFR exon 20 insertion mutations in a multicenter, open-label, multi-cohort clinical trial (CHRYSALIS, NCT02609776). The study included patients with locally advanced or metastatic NSCLC with EGFR exon 20 insertion mutations whose disease had progressed on or after platinum-based chemotherapy. Patients with untreated brain metastases and patients with a history of ILD requiring treatment with prolonged steroids or other immunosuppressive agents within the last 2 years were not eligible for the study.
In the efficacy population, EGFR exon 20 insertion mutation status was determined by prospective local testing using tissue (94%) and/or plasma (6%) samples. Of the 81 patients with EGFR exon 20 insertion mutations identified by local testing, plasma samples from 78/81 (96%) patients were tested retrospectively using Guardant360® CDx, identifying 62/78 (79%) samples with an EGFR exon 20 insertion mutation; 16/78 (21%) samples did not have an EGFR exon 20 insertion mutation identified.
Patients received RYBREVANT at 1050 mg (for patient baseline body weight < 80 kg) or 1400 mg (for patient baseline body weight ≥80 kg) once weekly for 4 weeks, then every 2 weeks thereafter until disease progression or unacceptable toxicity. The major efficacy outcome measure was overall response rate (ORR) according to Response Evaluation Criteria in Solid Tumors (RECIST v1.1) as evaluated by Blinded Independent Central Review (BICR). An additional efficacy outcome measure was duration of response (DOR) by BICR.
The efficacy population included 81 patients with NSCLC with EGFR exon 20 insertion mutation with measurable disease who were previously treated with platinum-based chemotherapy. The median age was 62 (range: 42 to 84) years, 59% were female; 49% were Asian, 37% were White, 2.5% were Black; 74% had baseline body weight <80 kg; 95% had adenocarcinoma; and 46% had received prior immunotherapy. The median number of prior therapies was 2 (range: 1 to 7). At baseline, 67% had Eastern Cooperative Oncology Group (ECOG) performance status of 1; 53% never smoked; all patients had metastatic disease; and 22% had previously treated brain metastases.
Efficacy results are summarized in Table 9.
|Prior Platinum-based Chemotherapy Treated(N=81)|
|Based on Kaplan-Meier estimates.NE=Not Estimable, CI=confidence interval.|
|Overall Response Rate (95% CI)||40% (29%, 51%)|
|Complete response (CR)||3.7%|
|Partial response (PR)||36%|
|Duration of Response (DOR)|
|Median, months (95% CI), months||11.1 (6.9, NE)|
|Patients with DOR ≥6 months||63%|
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