In simple words: This code is for a cancer drug called fam-trastuzumab deruxtecan-nxki (brand name Enhertu). It's given through an IV to treat a specific type of breast cancer that has spread to other parts of the body.This treatment is typically used after other treatments have been tried. Each unit of this code represents one milligram of the drug.

This code represents 1 mg of fam-trastuzumab deruxtecan-nxki, an antibody and topoisomerase inhibitor conjugate administered by intravenous infusion. It is used to treat adult patients with unresectable or metastatic HER2-positive breast cancer who have received two or more prior anti-HER2-based regimens in the metastatic setting. The recommended dosage is 5.4 mg/kg given as an intravenous infusion once every three weeks until disease progression or unacceptable toxicity.It is supplied as 100 mg lyophilized powder in a single-dose vial.

Example 1: A patient with unresectable HER2-positive breast cancer, who has progressed on two prior anti-HER2 therapies, receives 540 mg (540 units of J9358) of fam-trastuzumab deruxtecan-nxki every three weeks., A patient weighing 50 kg receives a dose of 270 mg (270 units of J9358) based on the recommended dosage of 5.4 mg/kg., If only a portion of the 100 mg vial is administered, and the remaining portion has to be discarded, modifier JW (Drug amount discarded/not administered to any patient) might be applicable (check individual payer guidelines).

Diagnosis of unresectable or metastatic HER2-positive breast cancer; documentation of prior anti-HER2 therapies; dosage administered; date and time of administration; any adverse reactions.

** This is a generic drug; the brand name is Enhertu. J codes represent drugs that cannot be self-administered, chemotherapy drugs, immunosuppressive drugs, inhalation solutions, and other miscellaneous drugs. This code represents the drug supply. Check with individual payers for coverage of drug administration.