Enfortumab Vedotin for Urothelial Cancer: Benefits, Side Effects, and Effectiveness

What Is Enfortumab Vedotin?

Enfortumab vedotin is a targeted cancer medicine (acts specifically on the cancer cells) and one of the first agents developed to treat urothelial carcinoma. Enfortumab Vedotin is frequently used as a salvage treatment and is indicated in:

• Individuals with advanced bladder cancer who have relapsed despite first-line therapy.
• Patients who do not respond well to immunotherapy for bladder cancer.

The United States Food and Drug Administration (US FDA) approved the drug in 2019.

For Patients

How Does Enfortumab Vedotin Work?

Enfortumab vedotin is an antibody-drug conjugate that contains components like:

• Monomethyl auristatin E (MMAE), which will help disrupt the cancer cells.
• Nectin-4-expressing cells bind to Enfortumab vedotin, and the resulting Enfortumab-Nectin-4 complex is internalized by the cell.

This drug acts like an innovative delivery system. It helps deliver medicine into cancer cells, providing a targeted approach. This will enable the breakdown of the cell's internal structure until its functions are halted. This is what is known medically as apoptosis. Apoptosis is a simple process of cell death and our body’s way of clearing out damaged cells.

Who Can Use Enfortumab Vedotin?

Enfortumab vedotin is mainly indicated in:

• Adult patients with advanced or metastatic urothelial carcinoma.
• Patients who are unresponsive or have stopped responding to other therapies, like platinum-based chemotherapy and immune checkpoint inhibitors.
• Potential treatment for recurrent or refractory cancer.
• The FDA has approved its use in combination with Pembrolizumab as first-line therapy for certain patients with advanced disease who are ineligible for cisplatin-based chemotherapy.

Enfortumab Vedotin Dosage

An intravenous infusion should be given for 30 minutes at a dose of 1.25 mg/kg (milligram/kilogram) of the drug up to a limit of 125 mg for patients under 100 kilograms on days one, eight, and fifteen of a 28-day cycle until disease progression or intolerable toxicity occurs.

Directions for Administration and Preparation:

• Administered only through the intravenous route.

• Handling or disposal instructions that may apply.

• Sterile water for injection is used to rehydrate the vial before administration.

• Subsequently, an intravenous infusion package containing either 5% Dextrose injection, USP, 0.9% sodium chloride injection, USP, or lactated Ringer's injection, USP, is used to dilute the reconstituted solution.

Overdose:

Overdose may increase the risk of serious side effects such as severe nausea, vomiting, neuropathy (nerve damage causing symptoms), or dermatitis (skin inflammation). Symptomatic and supportive treatment is recommended.

Warnings and Precautions

• Enfortumab vedotin can cause serious skin reactions like Stevens-Johnson syndrome (SJS). Some can be life-threatening. If this happens, the drug must be stopped permanently.
• Nerve problems, such as tingling or numbness, may occur. This can happen even without prior nerve issues. The dose may be paused or reduced. In case of severe nerve damage, stop the drug completely.
• Blood sugar levels can rise sharply. A serious condition called diabetic ketoacidosis has been reported. This can occur with or without diabetes.
• Some patients may develop eye problems, such as blurred vision or eye pain. Treatment may need to be paused or the dose reduced.
• Some patients develop lung inflammation. Ongoing or severe lung symptoms require stopping the drug.
• The medicine can harm an unborn baby. It should not be used during pregnancy.
• If the drug leaks outside the vein, it can damage the skin and nearby tissue.

What Are the Side Effects of Enfortumab Vedotin and How to Manage Them?

The common side effects of Enfortumab Vedotin are:

1. General:

Fatigue, muscle weakness, or numbness. A decline in appetite, vomiting, loss of weight, tingling, alteration in taste,

2. Skin:

Body rash, hair fall, and dry skin.

3. Systemic:

• Kidney and liver test results may change during treatment.
• Blood counts can go down. This includes red blood cells, white blood cells, and platelets.
• Albumin, sodium, and phosphate levels in the blood may drop.
• Uric acid and lipase levels in the blood may increase.
• High blood sugar can develop. This is more common in people with diabetes or those prone to blood sugar changes.

4. Specific Side Effect:

Men taking these drugs can have problems with fertility, which might affect their ability to have children.

For Doctors

Mechanism of Action

Nectin-4-expressing cells bind to Enfortumab vedotin, and the resulting Enfortumab-Nectin-4 complex is internalized by the cell. Once inside the cell, MMAE is liberated from Enfortumab vedotin by proteolytic cleavage, disrupting the microtubule network, arresting the cell cycle, and eventually triggering apoptosis.

Pharmacodynamics

• Enfortumab vedotin works by preventing cancer cells from multiplying, leading to their death. It has not been particularly studied in patients with moderate to severe hepatic diseases (liver disease). However, similar medicines that contain monomethyl auristatin E (MMAE) have shown higher side effects in people with severe liver diseases.
• Enfortumab vedotin must not be administered to patients with blood glucose levels above 250 milligrams per day because it can cause considerable hyperglycemia and, in some instances, diabetic ketoacidosis.

Pharmacokinetics

Data from 748 patients across five studies were used for pharmacokinetic analysis. After a single dose and several doses, individuals with locally advanced or metastatic urothelial carcinoma and with other solid tumors had their Enfortumab vedotin-ejfv pharmacokinetics assessed.

Peak antibody-drug conjugate (ADC) concentrations were seen at the end of intravenous infusion. Repeated dosing of Enfortumab vedotin-ejfv in patients resulted in minimal accumulation of the antibody-drug conjugate and monomethyl auristatin E (MMAE). After one treatment cycle, steady-state levels of antibody-drug conjugate and monomethyl auristatin E were attained.

Distribution:

After administering Enfortumab vedotin-ejfv, the estimated average steady-state volume of distribution of the antibody-drug conjugate was 12.8 liters. In vitro, the plasma protein binding of monomethyl auristatin E ranged from 68 to 82 percent.

Elimination:

• Half-life: ADC - 3.6 days and MMAE - 2.6 days.
• Mean clearance: ADC - 0.11 L/h and MMAE - 2.11 L/h.
• Excretion: Feces - 17 % and urine - 6 % (mostly unchanged).

Metabolism:

While the catabolism of Enfortumab vedotin-ejfv in humans has not been studied, it is expected to be metabolized into small peptides, unconjugated MMAE, amino acids, and unconjugated MMAE-associated catabolites.

Immunogenicity

Like other protein-based medicines, this drug may trigger an immune response. Test results for antibodies can vary. They depend on how the test is performed, when samples are taken, which other medicines are used, and existing health conditions. At this time, it is not clear how these antibodies affect the drug's efficacy, safety, or metabolism.

Drug Interaction

Taking Enfortumab vedotin with certain strong medicines can increase the risk of side effects. Some drugs slow how the body breaks down MMAE, the active part of Enfortumab vedotin. This can raise MMAE levels in the blood and make side effects more severe. If these medicines are used together, patients should be closely monitored for signs of toxicity.

Nonclinical Toxicology- Mutagenesis, Carcinogenesis, and Fertility Impairment

• There have been no studies to see if Enfortumab vedotin-ejfv or MMAE can cause cancer.
• MMAE has been shown to damage genetic material in animal studies. This matches how the drug works by interfering with cell division.
• There have been no direct studies on fertility for Enfortumab vedotin-ejfv or MMAE.
• However, animal studies suggest the drug may reduce male fertility and affect reproductive function. The drug was administered for 13 weeks.

Clinical Trial Results

• This medication was taken by patients for a few months. Approximately one-third of the people participating used the drug for more than six months, and others for nearly a year.
• Among patients with advanced bladder cancer who had already received previous cancer treatments, the drug was used for an average of about five months. Nearly half of these patients experienced severe side effects. The most common were urinary tract infections, kidney damage, and pneumonia.
• Patients frequently experienced tingling or numbness in their hands or feet, as well as poor appetite. Some reported diarrhea, nausea, skin rashes, itching, and changes in taste. Anemia, low levels of albumin, salt, phosphate, or white blood cells, or other abnormalities were observed in some patients. Blood tests also showed high levels of blood sugar, creatinine, and liver enzymes.

A small number of patients developed fatal side effects. These included severe infections, organ failure, liver-related problems, very high blood sugar levels, and inflammation of the lungs.

Some patients had to stop treatment because of side effects, most often due to skin rashes or nerve damage. Many required temporary breaks in treatment, mainly because of fatigue, rashes, or nerve-related symptoms. Others needed dose reductions, usually due to nerve problems, skin reactions, poor appetite, or ongoing tiredness.

Use of Enfortumab Vedotin in Specific Populations:

• Patients With Hepatic Impairment:

This drug should not be used in people with moderate or severe liver problems.

• Patients With Renal Impairment:

No dose adjustment required.

• Pregnant Patients:

The drug can harm an unborn baby. There are no studies in pregnant women, so the risks are not fully known.

• Lactating Mothers:

There is insufficient data to determine whether the drug passes into breast milk or affects milk production. Mothers should not breastfeed during treatment and for three weeks after the last dose.

• Geriatric Patients:

In studies, patients aged 75 years and older did not show major differences in safety or effectiveness compared to younger patients.

• Pediatric Patients:

The drug has not been proven safe or beneficial in pediatric patients.

Conclusion

Enfortumab vedotin is a targeted cancer medicine used to treat advanced or metastatic urothelial carcinoma. It works by delivering a cancer-killing drug directly to cancer cells that express the protein Nectin-4. Even though it has a targeted approach, the drug can still cause side effects.

Common side effects include skin reactions, nerve damage in the hands or feet, and high blood sugar, along with other possible adverse effects. To determine whether this drug is suitable for your clinical scenario, consult a cancer specialist for further evaluation.