What the label lists and what reports show
Panitumumab side effects
Panitumumab's FDA label: “Most common adverse reactions (≥ 20%) of Vectibix as monotherapy are skin rash with variable presentations, paronychia, fatigue, nausea, and diarrhea.” FAERS holds 15,571 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 (1,876 reports).
- No generic listed
- Boxed warning
Check it at the source: the panitumumab FDA label on DailyMed (effective June 23, 2026, Amgen, Inc); the FDA FAERS public dashboard.
What does the label list?
From the label: adverse reactionsMost common adverse reactions (≥ 20%) of Vectibix as monotherapy are skin rash with variable presentations, paronychia, fatigue, nausea, and diarrhea.
Table 3. Adverse Reactions (≥ 10%) in Patients with KRAS G12C-Mutated CRC who Received Vectibix in Combination with Sotorasib in CodeBreaK 300
| Reaction | All Grades (%) | Grade 3 or 4 (%) | All Grades (%) | Grade 3 or 4 (%) |
|---|---|---|---|---|
| Rash Rash includes dermatitis acneiform, dermatosis, drug eruption, eczema, erythema,… | 87 | 26 | 8 | 2 |
| Dry skin Dry skin includes dry skin, xerosis, and xeroderma. | 28 | 0 | 2 | 0 |
| Pruritis | 17 | 0 | 4 | 0 |
| Nail Disorder Nail disorders include nail avulsion, nail cuticle fissure, nail disorder,… | 17 | 0 | 0 | 0 |
| Skin fissure | 13 | 0 | 0 | 0 |
| Palmar-plantar erythrodysesthesia syndrome | 13 | 0 | 10 | 4 |
| Diarrhea Diarrhea includes diarrhea, gastroenteritis, and diarrhea hemorrhagic. | 28 | 6 | 26 | 0 |
| Stomatitis Stomatitis includes mucosal inflammation, stomatitis, mouth ulceration,… | 26 | 0 | 14 | 0 |
| Nausea | 17 | 2.1 | 36 | 4 |
| Constipation | 15 | 2.1 | 10 | 0 |
| Abdominal pain Abdominal pain includes abdominal pain, abdominal pain upper, abdominal… | 15 | 0 | 18 | 2 |
| Vomiting | 13 | 2.1 | 10 | 2 |
| Fatigue Fatigue includes asthenia and fatigue. | 21 | 0 | 34 | 2 |
| Musculoskeletal pain Musculoskeletal pain includes arthralgia, back pain, myalgia,… | 21 | 2.1 | 14 | 2 |
| Hemorrhage Hemorrhage includes epistaxis, gastrointestinal hemorrhage, vaginal… | 13 | 2.1 | 2 | 0 |
| Conjunctivitis Conjunctivitis includes conjunctival hyperemia, conjunctivitis, and… | 11 | 0 | 2 | 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 in greater detail in other sections of the label: Dermatologic and Soft Tissue Toxicity [see Boxed Warning, Dosage and Administration (2.3) and Warnings and Precautions (5.1) ] Increased Tumor Progression, Increased Mortality, or Lack of Benefit in Patients with RAS -Mutant mCRC Receiving Vectibix Monotherapy or in Combination with Oxaliplatin-based Chemotherapy [see Indications and Usage (1) and Warnings and Precautions (5.2) ] Electrolyte Depletion/Monitoring [see Warnings and Precautions (5.3) ] Infusion Reactions [see Dosage and Administration (2.3) and Warnings and Precautions (5.4) ] Acute Renal Failure [see Warnings and Precautions (5.5) ] Pulmonary Fibrosis/Interstitial Lung Disease (ILD) [see Warnings and Precautions (5.6) ] Photosensitivity [see Warnings and Precautions (5.7) ] Ocular Toxicities [see Warnings and Precautions (5.8) ] Increased Mortality and Toxicity with Vectibix in combination with Bevacizumab and Chemotherapy [see Warnings and Precautions (5.9) ] Most common adverse reactions (≥ 20%) of Vectibix as monotherapy are skin rash with variable presentations, paronychia, fatigue, nausea, and diarrhea. …
Source: FDA drug label, Amgen, Inc, effective June 23, 2026 (SPL set e0fa4bca-f245-4d92-ae29-b0c630a315c2), via openFDA; the full label on DailyMed
What do FAERS reports show?
15,571 reports list panitumumab among the medicines taken, each a report of something that happened, not proof the medicine caused it; 2,610 are coded as a death and 5,318 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 22 reactions below, 15 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?
- Panitumumab: 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