What the label lists and what reports show

Talquetamab side effects

Talquetamab's FDA label: “The most common adverse reactions (≥20%) are pyrexia, CRS, dysgeusia, nail disorder, musculoskeletal pain, skin disorder, rash, fatigue, weight decreased, dry mouth, xerosis, dysphagia, upper respiratory tract infection, diarrhea, hypotension, and headache.” FAERS holds 2,046 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 cytokine release syndrome (489 reports).

No generic listed
Boxed warning

Check it at the source: the talquetamab FDA label on DailyMed (effective October 8, 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 TALVEY?
TALVEY may cause serious side effects, including: See " What is the most important information I should know about TALVEY? " Mouth problems and weight loss. Tell your healthcare provider or get medical help right away if you develop any of the following symptoms of mouth problems: changes in sense of taste dry mouth trouble swallowing mouth sores Your healthcare provider will monitor you for these symptoms and will monitor your weight during treatment with TALVEY. Tell your healthcare provider if you lose weight during treatment with TALVEY. Infections. TALVEY can cause serious infections that can be life-threatening and may lead to death. Your healthcare provider will monitor you for signs and symptoms of infection before and during treatment with TALVEY. […]

Source: FDA drug label, Janssen Biotech, Inc., effective October 8, 2025 (SPL set 9001355e-003d-4d4e-b4ce-337e0fd14952), via openFDA; the full label on DailyMed

What does the label list?

From the label: adverse reactions
The most common adverse reactions (≥20%) are pyrexia, CRS, dysgeusia, nail disorder, musculoskeletal pain, skin disorder, rash, fatigue, weight decreased, dry mouth, xerosis, dysphagia, upper respiratory tract infection, diarrhea, hypotension, and headache.

Table 13: Adverse Reactions (≥10%) in Patients with Relapsed or Refractory Multiple Myeloma Who Received TALVEY in MonumenTAL-1

System Organ Class Adverse Reaction	Any Grade (%)	Grade 3 or 4 (%)
Pyrexia Includes other related terms.	83	4.7 Only grade 3 adverse reactions occurred.
Fatigue	37	3.5
Chills	19	0
Pain	18	1.8
Edema	14	0
Injection site reaction	13	0
Cytokine release syndrome	76	1.5
Dysgeusia Dysgeusia: ageusia, dysgeusia, hypogeusia and taste disorder. Per CTCAE v4.03,…	70	0
Dry mouth	34	0
Dysphagia	23	0.9
Diarrhea	21	0.9
Stomatitis Stomatitis: cheilitis, glossitis, glossodynia, mouth ulceration, oral…	18	1.2
Nausea	18	0
Constipation	16	0
Oral disorder Oral disorder: oral disorder, oral dysesthesia, oral mucosal exfoliation,…	12	0
Nail disorder Nail disorder: koilonychia, nail bed disorder, nail cuticle fissure, nail…	50	0
Skin disorder Skin disorder: palmar-plantar erythrodysesthesia syndrome, palmoplantar…	41	0.3
Rash Rash: dermatitis, dermatitis acneiform, dermatitis contact, dermatitis exfoliative,…	38	3.5
Xerosis Xerosis: dry eye, dry skin and xerosis.	30	0
Pruritus	19	0.3
Musculoskeletal pain	43	3.2
Weight decreased	35	1.5
Upper respiratory tract infection	22	2.7
Bacterial infection including sepsis Bacterial infection including sepsis: bacteremia,…	19	9
COVID-19	11	2.7

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, continued
The following adverse reactions are also described elsewhere in the labeling: Cytokine Release Syndrome [see Warnings and Precautions (5.1) ] Neurologic Toxicity, including ICANS [see Warnings and Precautions (5.2) ] Oral Toxicity and Weight Loss [see Warnings and Precautions (5.4) ] Infections [see Warnings and Precautions (5.5) ] Cytopenias [see Warnings and Precautions (5.6) ] Skin Toxicity [see Warnings and Precautions (5.7) ] Hepatotoxicity [see Warnings and Precautions (5.8) ] The most common adverse reactions (≥20%) are pyrexia, CRS, dysgeusia, nail disorder, musculoskeletal pain, skin disorder, rash, fatigue, weight decreased, dry mouth, xerosis, dysphagia, upper respiratory tract infection, diarrhea, hypotension, and headache. ( 6.1 ) The most common Grade 3 or 4 laboratory abnormalities (≥30%) are lymphocyte count decreased, neutrophil count decreased, white blood cell decreased, and hemoglobin decreased. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Janssen Biotech, Inc. at 1-800-JANSSEN (1-800-526-7736) or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. …

Source: FDA drug label, Janssen Biotech, Inc., effective October 8, 2025 (SPL set 9001355e-003d-4d4e-b4ce-337e0fd14952), via openFDA; the full label on DailyMed

What do FAERS reports show?

2,046 reports list talquetamab among the medicines taken, each a report of something that happened, not proof the medicine caused it; 225 are coded as a death and 517 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 21 reactions below, 19 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

Cytokine Release Syndrome (named in the label)489
Dysgeusia (named in the label)192
Weight Decreased (named in the label)174
Immune Effector Cell-Associated Neurotoxicity Syndrome (named in the label)165
Ageusia (named in the label)157
Skin Exfoliation (named in the label)156
Dry Mouth (named in the label)133
Pyrexia (named in the label)122
Plasma Cell Myeloma115
Nail Disorder (named in the label)108
Off Label Use (a use or a product term, not a reaction)108
Rash (named in the label)100
Onychomadesis (named in the label)92
Fatigue (named in the label)91
Death (an outcome recorded in the report)89
Taste Disorder (named in the label)88
Neutropenia (named in the label)83
Dry Skin (named in the label)78
Infection (named in the label)78
Decreased Appetite (named in the label)73
Drug Ineffective (a use or a product term, not a reaction)66
Dysphagia (named in the label)65
Inappropriate Schedule Of Product Administration (a use or a product term, not a reaction)62
Anaemia59
Thrombocytopenia (named in the label)55

Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms

What next?

Talquetamab: 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