Kadcyla | ado-trastuzumab emtansine

Drug Class: Antibody-Drug Conjugate
Manufacturer: Genentech
Approval Date: February 2013

What is Kadcyla

Kadcyla is a drug made up of an antibody that is bound ("conjugated") to a chemotherapy drug and is used for treating patients with HER2-positive (HER2+) metastatic breast cancer. Kadcyla uses the same antibody used in Herceptin (trastuzumab), but in Kadcyla, the antibody is also bound to the chemotherapy drug DM1.The antibody portion of Kadcyla binds to HER2 on breast cancer cells, which blocks growth signals and marks the cancer cell so that the body’s immune system attacks it. Kadcyla enters into the cancer cell and releases DM1 which inhibits microtubules used for  many cell processes, causing the cancer cell to die. As a result the cancer cell load decreases.

Also Read: Kadcyla, an Antibody Drug Conjugate for Breast Cancer Treatment

What is Kadcyla used for

Kadcyla can be used by itself in patients with HER2+ metastatic breast cancer if patients have previously received trastuzumab and taxane therapy. Patients should either have already received therapy for metastatic disease (spread beyond the breast/lymph nodes), or have an early-stage cancer that recurred within 6 months of completing primary (adjuvant) therapy.

How well does Kadcyla work

Safety and efficacy of Kadcyla versus previously standard treatment (Tykerb + Xeloda) was evaluated in the EMILIA trial with 991 HER2+ patients. It found:

• Kadcyla-treated patients lived a median of 5.8 months longer than those on standard treatment (30.9 months with Kadcyla vs. 25.1 months with standard treatment)
• Kadcyla-treated patients had a significant 32% reduction in risk of dying
• Kadcyla-treated patients lived 3.2 months longer without their disease getting worse (9.6 months with Kadcyla vs. 6.4 months with standard treatment)
• Kadcyla-treated patients experienced less severe adverse effects than those on standard treatment (43.1% with Kadcyla vs. 59.2% in standard treatment).

How is Kadcyla different from other HER2-directed therapies (like Herceptin and Perjeta)

• Kadcyla is an antibody that is physically attached to a chemotherapy drug.
• Kadcyla helps deliver chemotherapy specifically to cancer cells.
• Kadcyla may be used by itself and doesn’t need another drug in combo with it.

What is the dosage of Kadcyla

Kadcyla is supplied as sterile, preservative free powder in 100 mg or 160 mg single-use vials. It is dissolved in sterile water for injection and the dose is diluted into 250 mL 0.9% NaCl for administration. Dextrose should not be used.

Dosing is 3.6 mg/kg administered through IV infusion over 30-90 minutes once every 3 weeks.

What are the side effects of Kadcyla

Common: fatigue, nausea, headache, musculoskeletal pain, constipation, thrombocytopenia, increased transaminases

Serious: Hepatotoxicity, cardiac toxicity, embryo-fetal toxicity, pulmonary toxicity, neurotoxicity, thrombocytopenia, infusion-related hypersensitivity reactions

Kadcyla Drug interactions

No formal Kadcyla drug-drug interaction studies have been conducted. Certain drugs that decrease the breakdown of DM1 in the liver may increase DM1 to toxic levels in the blood. Drugs that should be avoided include: ketoconazole, itraconazole, clarithromycin, atazanavir, indinavir, nefazodone, nelfinavir, ritonavir, saquinavir, telithromycin, and voriconazole.

What is the price of Kadcyla

Average wholesale price is $3,328.28 for the 100 mg vial and $5325.25 for the 160 mg vial. For a 70 kg (154 pounds) individual, each dose is estimated to cost $8,653.53 (one 100 mg vial + one 160 mg vial), and $83,073.89 for a 9.6 month course.  

How to obtain prescription cost assistance for Kadcyla

Kadcyla offers 3 financial assistance programs: Kadcyla Access Solutions, BioOncology Co-pay Card, and Genentech Access to Care Foundation (GATCF).

References

KADCYLA [prescribing information]. South San Francisco, CA: Genentech, Inc; 2013.

RED BOOK Online. KADCYLA. Truven Health Analytics, Inc.; 2014.

The material on this site is for information only and is not a substitute for medical advice, diagnosis or treatment provided by a qualified healthcare provider.

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