What the label lists and what reports show
Amivantamab and hyaluronidase side effects
Amivantamab and hyaluronidase's FDA label: “The most common adverse reactions (≥ 20%) were rash, nail toxicity, musculoskeletal pain, fatigue, stomatitis, edema, nausea, diarrhea, vomiting, constipation, decreased appetite, and headache.” FAERS holds 125 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 rash (24 reports).
- No generic listed
Check it at the source: the amivantamab and hyaluronidase FDA label on DailyMed (effective June 17, 2026); 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 FASPRO?RYBREVANT FASPRO may cause serious side effects, including: allergic and injection-related reactions. Allergic and injection-related reactions are common and can be severe or serious. Tell your healthcare provider right away if you get any of the following symptoms during or after your injection of RYBREVANT FASPRO: shortness of breath fever chills flushing chest discomfort dizziness or lightheadedness vomiting lung problems. RYBREVANT FASPRO can cause lung problems that can lead to death. Symptoms may be similar to those symptoms from lung cancer. Tell your healthcare provider right away if you get any new or worsening lung symptoms, including: shortness of breath cough fever blood clot problems. RYBREVANT FASPRO, when given in combination with lazertinib, can cause blood clots in the veins of your legs (deep vein thrombosis) or lungs (pulmonary embolism) that can lead to death. […]
Source: FDA drug label, Janssen Biotech, Inc., effective June 17, 2026 (SPL set 9e58b045-e352-4f62-99bf-77fae1bebc69), 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, musculoskeletal pain, fatigue, stomatitis, edema, nausea, diarrhea, vomiting, constipation, decreased appetite, and headache.
Table 12: 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 intravenous amivantamab 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: Hypersensitivity and Administration-Related Reactions [see Warnings and Precautions (5.1) ] Interstitial Lung Disease/Pneumonitis [see Warnings and Precautions (5.2) ] Venous Thromboembolic Events with Concomitant Use with Lazertinib [see Warnings and Precautions (5.3) ] Dermatologic Adverse Reactions [see Warnings and Precautions (5.4) ] Ocular Toxicity [see Warnings and Precautions (5.5) ] RYBREVANT FASPRO in Combination with Lazertinib The most common adverse reactions (≥ 20%) were rash, nail toxicity, musculoskeletal pain, fatigue, stomatitis, edema, nausea, diarrhea, vomiting, constipation, decreased appetite, and headache. ( 6.1 ) The most common Grade 3 or 4 laboratory abnormalities (≥ 2%) were decreased lymphocyte count, decreased sodium, decreased potassium, decreased albumin, increased alanine aminotransferase, increased aspartate aminotransferase, decreased platelet count, increased gamma-glutamyl transferase, and decreased hemoglobin. (6.1) Intravenous Amivantamab 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. …
Source: FDA drug label, Janssen Biotech, Inc., effective June 17, 2026 (SPL set 9e58b045-e352-4f62-99bf-77fae1bebc69), via openFDA; the full label on DailyMed
What do FAERS reports show?
125 reports list amivantamab and hyaluronidase among the medicines taken, each a report of something that happened, not proof the medicine caused it; 1 are coded as a death and 17 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. Of the 24 reactions below, 14 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.
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 and hyaluronidase: 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