Eribulin Mesylate Injection

• Type: Chemotherapy medication

• Drug Class: Microtubule dynamics inhibitor (synthetic analog of halichondrin B, a natural product from marine sponges)

• Form: Sterile solution for intravenous (IV) administration

How It Works

• Eribulin binds to microtubules and inhibits their growth, preventing cancer cells from properly forming the mitotic spindle needed for cell division.

• Unlike other microtubule-targeting drugs (like taxanes or vinca alkaloids), it does not affect microtubule shortening — this unique mechanism leads to irreversible mitotic blockade and cancer cell death.

Common Uses

Eribulin mesylate is mainly used for:

• Metastatic breast cancer – in patients who have already received at least two prior chemotherapy regimens (including an anthracycline and a taxane)

• Unresectable or metastatic liposarcoma – in patients who have received prior chemotherapy

Advantages

• Works even in heavily pretreated patients with advanced cancer

• Has a unique mechanism compared to other microtubule inhibitors, useful in resistant tumors

• Generally does not cause significant neuropathy compared to taxanes

• Administered on a convenient day 1 and day 8 schedule every 21-day cycle

Possible Side Effects

Common:

• Low white blood cell counts (neutropenia) – increases infection risk

• Fatigue

• Nausea, vomiting

• Hair loss (alopecia)

• Constipation

• Peripheral neuropathy (numbness, tingling – but usually milder than with taxanes)

Serious but Less Common:

• Febrile neutropenia (infection with low WBC count)

• Heart rhythm changes (QT interval prolongation – requires ECG monitoring in some cases)

• Severe allergic reactions (rare)

Precautions

• Blood counts should be checked before each dose — dose may be delayed if counts are too low

• Use cautiously in patients with liver impairment, as metabolism is hepatic

• Monitor for peripheral neuropathy and adjust dose if symptoms become severe

• ECG monitoring recommended for patients with risk factors for QT prolongation

• Pregnancy should be avoided – potential harm to fetus