Medical Editor: John P. Cunha, DO, FACOEP
What Is Kadcyla?
What Are Side Effects of Kadcyla?
Common side effects of Kadcyla include:
- musculoskeletal pain,
- low platelet count,
- liver problems,
- low levels of red blood cells,
- nerve problems, and
- low levels of potassium in the blood.
Dosage for Kadcyla?
Kadcyla is for intravenous infusion only. Kadcyla is given as an intravenous infusion in 21-day cycles.
What Drugs, Substances, or Supplements Interact with Kadcyla?
While a patient is receiving Kadcyla therapy, drugs containing ketoconazole, itraconazole, clarithromycin, atazanavir, indinavir, nefazodone, nelfinavir, ritonavir, saquinavir, telithromycin, and voriconazole should be avoided.
Kadcyla During Pregnancy and Breastfeeding
Kadcyla can cause fetal harm when administered to a pregnant woman. It is not known if Kadcyla is excreted in human milk. However, because of the potential for serious adverse reactions in nursing infants, a decision should be made whether to discontinue breastfeeding or discontinue Kadcyla, taking into account the importance of the drug to the mother.
Our Kadcyla (ado-trastuzumab emtansine) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
The following adverse reactions are discussed in greater detail in other sections of the label:
- Hepatotoxicity [see WARNINGS AND PRECAUTIONS]
- Left Ventricular Dysfunction [see WARNINGS AND PRECAUTIONS]
- Embryo-Fetal Toxicity [see WARNINGS AND PRECAUTIONS]
- Pulmonary Toxicity [see WARNINGS AND PRECAUTIONS]
- Infusion-Related Reactions, Hypersensitivity Reactions [see WARNINGS AND PRECAUTIONS]
- Hemorrhage [see WARNINGS AND PRECAUTIONS]
- Thrombocytopenia [see WARNINGS AND PRECAUTIONS]
- Neurotoxicity [see WARNINGS AND PRECAUTIONS]
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.
In clinical trials, KADCYLA has been evaluated as single-agent in 884 patients with HER2- positive metastatic breast cancer. The most common (frequency ≥ 25%) adverse drug reactions (ADRs) seen in 884 patients treated with KADCYLA were fatigue, nausea, musculoskeletal pain, hemorrhage, thrombocytopenia, headache, increased transaminases, constipation and epistaxis.
The ADRs described in Table 6 were identified in patients with HER2-positive metastatic breast cancer treated in a randomized trial (Study 1) [see Clinical Studies]. Patients were randomized to receive KADCYLA or lapatinib plus capecitabine. The median duration of study treatment was 7.6 months for patients in the KADCYLA-treated group and 5.5 months and 5.3 months for patients treated with lapatinib and capecitabine, respectively. Two hundred and eleven (43.1%) patients experienced ≥ Grade 3 adverse events in the KADCYLA-treated group compared with 289 (59.2%) patients in the lapatinib plus capecitabine-treated group. Dose adjustments for KADCYLA were permitted [see DOSAGE AND ADMINISTRATION]. Thirty-two patients (6.5%) discontinued KADCYLA due to an adverse event, compared with 41 patients (8.4%) who discontinued lapatinib, and 51 patients (10.5%) who discontinued capecitabine due to an adverse event. The most common adverse events leading to KADCYLA withdrawal were thrombocytopenia and increased transaminases. Eighty patients (16.3%) treated with KADCYLA had adverse events leading to dose reductions. The most frequent adverse events leading to dose reduction of KADCYLA (in ≥ 1% of patients) included thrombocytopenia, increased transaminases, and peripheral neuropathy. Adverse events that led to dose delays occurred in 116 (23.7%) of KADCYLA treated patients. The most frequent adverse events leading to a dose delay of KADCYLA (in ≥ 1% of patients) were neutropenia, thrombocytopenia, leukopenia, fatigue, increased transaminases and pyrexia.
Table 6 reports the ADRs that occurred in patients in the KADCYLA-treated group (n=490) of the randomized trial (Study 1). Selected laboratory abnormalities are shown in Table 7. The most common ADRs seen with KADCYLA in the randomized trial (frequency > 25%) were nausea, fatigue, musculoskeletal pain, hemorrhage, thrombocytopenia, increased transaminases, headache, and constipation. The most common NCI–CTCAE (version 3) ≥ Grade 3 ADRs (frequency >2%) were thrombocytopenia, increased transaminases, anemia, hypokalemia, peripheral neuropathy and fatigue.
Table 6: Summary of Adverse Drug Reactions Occurring in Patients on the KADCYLA
Treatment Arm in the Randomized Trial (Study 1)
|Adverse Drug Reactions
System Organ Class
Frequency rate %
|Lapatinib (1250 mg) +
Capecitabine (2000 mg/m2)
Frequency rate %
|Grade 3 – 4
|Grade 3 – 4
|Blood and Lymphatic System Disorders|
|Left ventricular dysfunction||1.8||0.2||3.3||0.4|
|General Disorders and Administration|
|Nodular regenerative hyperplasia*||0.4||ND||0||0|
|Injury, Poisoning, and Procedural|
|Infections and Infestations|
|Urinary tract infection||9.4||0.6||3.9||0|
|Blood alkaline phosphatase increased||4.7||0.4||3.7||0.4|
|Metabolism and Nutrition Disorders|
|Musculoskeletal and Connective Tissue Disorders|
|Nervous System Disorders|
|Respiratory, Thoracic, and Mediastinal Disorders|
|Skin and Subcutaneous Tissue Disorders|
|* Nodular Regenerative Hyperplasia and Portal Hypertension occurred in the same patient.
ND = Not determined
Table 7: Selected Laboratory Abnormalities
|Lapatinib (1250 mg) + Capecitabine (2000 mg/m2)|
|Decreased platelet count||83||14||3||21||<1||<1|
Hepatic failure has been observed in two patients (0.2%) with HER2-positive metastatic breast cancer in clinical trials (n=884) with KADCYLA as single-agent.
As with all therapeutic proteins, there is the potential for an immune response to KADCYLA. A total of 836 patients from six clinical studies were tested at multiple time points for antitherapeutic antibody (ATA) responses to KADCYLA. Following KADCYLA dosing, 5.3% (44/836) of patients tested positive for anti-KADCYLA antibodies at one or more post-dose time points. The presence of KADCYLA in patient serum at the time of ATA sampling may interfere with the ability of this assay to detect anti-KADCYLA antibodies. As a result, data may not accurately reflect the true incidence of anti-KADCYLA antibody development. In addition, neutralizing activity of anti-KADCYLA antibodies has not been assessed.
Immunogenicity data are highly dependent on the sensitivity and specificity of the test methods used. Additionally, the observed incidence of a positive result in a test method may be influenced by several factors, including sample handling, timing of sample collection, drug interference, concomitant medication and the underlying disease. Therefore, comparison of the incidence of antibodies to KADCYLA with the incidence of antibodies to other products may be misleading. Clinical significance of anti-KADCYLA antibodies is not yet known.
The following adverse reactions have been identified during post-approval use of KADCYLA. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure
- Tumor lysis syndrome (TLS): Cases of possible TLS have been reported in patients treated with KADCYLA. Patients with significant tumor burden (e.g., bulky metastases) may be at a higher risk. Patients could present with hyperuricemia, hyperphosphatemia, and acute renal failure which may represent possible TLS. Providers should consider additional monitoring and/or treatment as clinically indicated.
Read the entire FDA prescribing information for Kadcyla (Ado-trastuzumab Emtansine Injection for IV Use)