Sacituzumab Govitecan: Uses, Mechanism, Dosage, and Side Effects

What Is Sacituzumab Govitecan?

Sacituzumab govitecan is an anticancer medicine. Doctors use this medicine for the treatment of triple-negative breast cancer (TNBC). As an antibody-drug conjugate medicine, this can specifically identify breast cancer cells and target them. Unlike common chemotherapeutic medicines, which target healthy cells too, this medicine can only locate dangerous cancer cells and kill them.

Most breast cancers respond to different treatments like hormonal therapy or targeted gene therapy. Because triple-negative cancer cells do not respond to any such treatments, Sacituzumab Govitecan can target them and destroy them.

How Does Sacituzumab Govitecan Work?

Doctors use female hormones like estrogen or progesterone-based medicines to kill breast cancer cells. Also, HER2 (Human epidermal growth factor receptor 2)- targeted medicines can act on cancer cells and cure breast cancer. In TNBC, the receptors for these three types of drugs are absent. As a result, current medicines are not fully effective in curing TNBC.

Mechanism of Action:

Sacituzumab govitecan is an antibody-drug conjugate medicine that has three components. The antibody in this medicine targets specific cancer cells. The main portion of this medicine is the chemical that can kill your cancer cells. The third component joins these two components.

A young TNBC cancer cell expresses antigen 2 (Trop-2) on its surface, which promotes cancer cell growth. The humanized anti-TROP-2 monoclonal antibody present in Sacituzumab govitecan binds to cancer cells that express Trop-2 and attaches to them. This monoclonal antibody also delivers SN-38 (7-ethyl-10-hydroxycamptothecin), a chemotherapy drug, within the cancer cells. This not only destroys the genetic component of cancer cells but also kills them via an antigen-antibody reaction. Thus, Sacituzumab govitecan’s mechanism of action specifically targets and kills TNBC cancer cells, without harming the healthy cells in the body.

What Are the Approved Uses of Sacituzumab Govitecan?

Doctors use Sacituzumab govitecan for the following conditions;

1. If the patient has TNBC that is locally spreading or has spread to the surrounding tissue, this medicine can be given. Also, such patients must have received two or more systemic therapies before, or at least one of them, for the metastatic spread of breast cancer.

2. It can be used in hormone receptor-positive and HER2-negative cancers where patients have received hormone therapy and at least two systemic therapies for metastatic breast cancer.

However, in 2021, the Food and Drug Administration (FDA) permitted its use in metastatic urothelial cancer. Such cases must have received prior platinum-containing chemotherapy and either a programmed death receptor-1 (PD-1) or programmed death-ligand 1 (PD-L1) inhibitor. However, this approval was withdrawn in November 2024 due to a failed trial.

What Is the Dosage of Sacituzumab Govitecan?

During the Sacituzumab govitecan dosage schedule phase, doctors follow a 21-day cycle. In those 21 days, doctors give you medicine on the 1st and 8th day of the cycle. Based on your body weight and condition, 8-10 mg/kg of Sacituzumab govitecan is given. Doctors can continue to provide you with this medicine until,

1. It cures your cancer completely.

2. It is not causing severe side effects.

Doctors give the medicine via an intravenous (IV) drip. During the first drip, doctors give it very slowly, taking over three hours. Also, they look for any unnatural reaction during the initial phase of infusion. However, during the later phase, the drip is administered within 1 to 2 hours.

What Are the Side Effects of Sacituzumab Govitecan?

Patients can experience two types of side effects during Sacituzumab govitecan treatment.

1. Common Side Effects:

The common side effects include:

• Nausea and vomiting.

• Allergic or hypertensive reactions during the treatment phase can cause skin rashes, itching, and burning sensations.

• Diarrhea, along with severe abdominal cramping and pain, may happen. If the condition is severe, you can see blood in your poop or black poop.

• Hair fall.

• Sacituzumab govitecan can destroy your white blood cells, like neutrophils. This can lower your immunity and lead to infections, cough, and fever.

As side effects are common during Sacituzumab govitecan treatment, doctors use precautions to protect you. Before starting treatment, they give 2 or 3 medicines to reduce side effects such as skin rash, nausea, and vomiting. These medicines are Dexamethasone (steroid) with either a 5-HT3 (Serotonin Type 3) receptor antagonist or an NK1 (neurokinin-1 receptors) receptor antagonist.

2. Severe Side Effects:

Sacituzumab govitecan side effects can be serious in the following conditions:

If the patient has a lower level of diphosphate-glucuronosyl transferase 1A1 (UGT1A1), a liver enzyme in the body, they can face severe issues.

• In such cases, it can lead to the death of a large number of blood cells in your body.
• The patient can experience severe anemia or neutropenia (low amount of neutrophils) in the body.

If you are pregnant, you should not take this drug.

• It can severely harm your unborn baby and your health.
• It can harm your reproductive potential, too.

When to See a Doctor?

A doctor will decide whether you will need Sacituzumab govitecan for your breast cancer treatment or not. Also, it requires a proper medical evaluation before starting. However, if you notice any of the following changes, you should talk to your doctor.

1. Any change in the shape and size of your breast, as in the case of breast cancer, you can sense a lump in your breast. Also, your affected breast might appear heavy.

2. Any change in the shape, size, and color of the nipple. In most cases, nipples appear inverted.

3. You can see peeling, hard skin formation, and flaking of the areola (pigmented skin around the nipple).

4. Look for any watery or milky discharge from the nipple.

Also, during therapy, if you notice any of the following changes, talk to your doctor immediately.

1. Severe skin rash with itching, redness, and blistering.

2. Swelling of your face, lips, and difficulty in breathing.

3. Severe diarrhea along with blood in your poop.

4. Severe fatigue, dizziness, cough, and cold.

Conclusion

If you have triple-negative breast cancer, it is difficult to treat. Sacituzumab govitecan, an antibody-drug conjugate, is a useful treatment in such cases. It can identify your cancer cells and kill them. Despite Sacituzumab govitecan’s safety profile, it can cause mild to moderate side effects. However, if severe side effects occur, the medicine must be stopped. If you have further queries, you can consult a cancer specialist for a proper evaluation.

Key Takeaways

• Triple-negative breast cancer (TNBC) is challenging to treat.

• Sacituzumab govitecan can identify TNBC cancer cells and kill them.

• It is an antibody-drug conjugate medicine based on a human monoclonal antibody.

• Sacituzumab govitecan can cause severe side effects, like an allergy or vomiting.