What the label lists and what reports show
Amivantamab side effects
Amivantamab's FDA label: “The most common adverse reactions (≥ 20%) were rash, nail toxicity, infusion-related reaction, musculoskeletal pain, stomatitis, edema, VTE, paresthesia, fatigue, diarrhea, constipation, COVID-19, hemorrhage, dry skin, decreased appetite, pruritus, and nausea.” FAERS holds 3,268 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is infusion related reaction (721 reports).
- No generic listed
Check it at the source: the amivantamab FDA label on DailyMed (effective November 11, 2025); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of RYBREVANT?RYBREVANT may cause serious side effects, including: infusion-related reactions. Infusion-related reactions are common but can be severe or serious and can include life-threatening (anaphylaxis) allergic reaction. Tell your healthcare provider right away if you get any of the following symptoms during your infusion of RYBREVANT: shortness of breath, difficulty breathing, or wheezing chest discomfort swelling of your eyes, lips, or tongue fever chills numbness of the tongue, lips, cheeks, or gums flushing skin rash, hives, or itching nausea or vomiting stomach cramps lightheadedness, dizziness, or fainting headache lung problems. RYBREVANT may cause lung problems that may lead to death. Symptoms may be similar to those symptoms from lung cancer. […]
Source: FDA drug label, Janssen Biotech, Inc., effective November 11, 2025 (SPL set 1466c070-9f97-4fa4-a955-6a6b59981fb8), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsThe most common adverse reactions (≥ 20%) were rash, nail toxicity, infusion-related reaction, musculoskeletal pain, stomatitis, edema, VTE, paresthesia, fatigue, diarrhea, constipation, COVID-19, hemorrhage, dry skin, decreased appetite, pruritus, and nausea.
Table 10: Adverse Reactions (≥ 10%) in Patients with NSCLC with Exon 19 Deletion or Exon 21 L858R Substitution Mutations in MARIPOSA
| Reaction | All Grades (%) | Grade 3 or 4 (%) | All Grades (%) | Grade 3 or 4 (%) |
|---|---|---|---|---|
| Rash Grouped terms | 86 | 26 | 48 | 1.2 |
| Nail toxicity | 71 | 11 | 34 | 0.7 |
| Dry skin | 25 | 1 | 18 | 0.2 |
| Pruritus | 24 | 0.5 | 17 | 0.2 |
| Infusion-related reaction Applicable for RYBREVANT only | 63 | 6 | 0 | 0 |
| Musculoskeletal pain | 47 | 2.1 | 39 | 1.9 |
| Stomatitis | 43 | 2.4 | 27 | 0.5 |
| Diarrhea | 31 | 2.6 | 45 | 0.9 |
| Constipation | 29 | 0 | 13 | 0 |
| Nausea | 21 | 1.2 | 14 | 0.2 |
| Vomiting | 12 | 0.5 | 5 | 0 |
| Abdominal pain | 11 | 0 | 10 | 0 |
| Hemorrhoids | 10 | 0.2 | 2.1 | 0.2 |
| Edema | 43 | 2.6 | 8 | 0 |
| Fatigue | 32 | 3.8 | 20 | 1.9 |
| Pyrexia | 12 | 0 | 9 | 0 |
| Venous thromboembolism | 36 | 11 | 8 | 2.8 |
| Hemorrhage | 25 | 1 | 13 | 1.2 |
| Paresthesia | 35 | 1.7 | 10 | 0.2 |
| Dizziness | 14 | 0 | 10 | 0 |
| Headache | 13 | 0.2 | 13 | 0 |
| COVID-19 | 26 | 1.7 | 24 | 1.4 |
| Conjunctivitis | 11 | 0.2 | 1.6 | 0 |
| Decreased appetite | 24 | 1 | 18 | 1.4 |
| Cough | 19 | 0 | 23 | 0 |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedThe following adverse reactions are discussed elsewhere in the labeling: Infusion-Related Reactions [see Warnings and Precautions (5.1) ] Interstitial Lung Disease/Pneumonitis [see Warnings and Precautions (5.2) ] Venous Thromboembolic Events [see Warnings and Precautions (5.3) ] Dermatologic Adverse Reactions [see Warnings and Precautions (5.4) ] Ocular Toxicity [see Warnings and Precautions (5.5) ] RYBREVANT in Combination with Lazertinib The most common adverse reactions (≥ 20%) were rash, nail toxicity, infusion-related reaction, musculoskeletal pain, stomatitis, edema, VTE, paresthesia, fatigue, diarrhea, constipation, COVID-19, hemorrhage, dry skin, decreased appetite, pruritus, and nausea. ( 6.1 ) The most common Grade 3 or 4 laboratory abnormalities (≥ 2%) were decreased albumin, decreased sodium, increased ALT, decreased potassium, decreased hemoglobin, increased AST, increased GGT, and increased magnesium. ( 6.1 ) RYBREVANT in Combination with Carboplatin and Pemetrexed The most common adverse reactions (≥ 20%) were rash, nail toxicity, infusion-related reaction, fatigue, nausea, stomatitis, constipation, edema, decreased appetite, musculoskeletal pain, vomiting, and COVID-19. …
Source: FDA drug label, Janssen Biotech, Inc., effective November 11, 2025 (SPL set 1466c070-9f97-4fa4-a955-6a6b59981fb8), via openFDA; the full label on DailyMed
What do FAERS reports show?
3,268 reports list amivantamab among the medicines taken, each a report of something that happened, not proof the medicine caused it; 246 are coded as a death and 658 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Reports rose sharply in 2025 (1,482, against a median of 0 a year): FAERS counts follow reporting, which news, litigation and label changes can drive, not how often a reaction happens. Of the 22 reactions below, 13 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Amivantamab: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions