Chemotherapy: Mitotic Inhibitors

Mitotic inhibitors are a type of chemotherapy used to treat many cancers. Often, they are used to treat non-small cell lung cancer (NSCLC). They work by blocking the process of cell division. This kills cells that divide quickly, such as cancer cells.^1,2

You may receive mitotic inhibitors along with other treatments, including other types of chemotherapy. Talk to your doctor about the risks and benefits of mitotic inhibitors, as well as what to expect during treatment.^1,2

How do mitotic inhibitors work?

Mitotic inhibitors work by blocking the process of cell division. This process is called mitosis. During mitosis, a single cell copies its DNA and splits into 2 cells.¹

Mitotic inhibitors disrupt the function of microtubules. These are proteins that provide structure to the cells. During cell division, microtubules help separate DNA between the 2 cells. Two types of mitotic inhibitors disrupt microtubules in different ways:^1,3

• Vinca alkaloids – prevent the formation of the microtubule structures needed for cell division
• Taxanes – prevent microtubules from splitting cells apart during cell division

With either type, the result is that mitosis cannot happen. When they cannot split into new cells, cancer cells die.¹

Examples of mitotic inhibitors

Mitotic inhibitors used to treat lung cancer include:²

• Navelbine® (vinorelbine)
• Taxol® (paclitaxel)
• Taxotere® (docetaxel)
• Velban® (vinblastine)

Paclitaxel and docetaxel are taxanes. Vinblastine and vinorelbine are vinca alkaloids. A mitotic inhibitor may be combined with other types of chemotherapy treatment for certain forms of NSCLC. Taxanes and vinca alkaloids are also used to treat other cancers.^2,4

What are the possible side effects?

Mitotic inhibitors damage cells that divide quickly. This is why they kill cancer cells. But all chemotherapy drugs, including mitotic inhibitors, can damage healthy cells as well. This leads to side effects. Side effects can vary depending on the specific drug you are taking.²

Common side effects of mitotic inhibitors include:^4-7

• Low white blood cell counts, which can increase the risk of infection
• Weakness and numbness in hands and feet
• Joint and muscle pain
• Rash or irritation at the injection site
• Nausea and vomiting
• Mouth or lip sores
• Swelling of hands, face, or feet
• Bleeding events
• Low blood pressure
• Hair loss

Serious side effects are possible. Several mitotic inhibitors have boxed warnings, the strictest warning from the US Food and Drug Administration (FDA). Paclitaxel, docetaxel, and vinorelbine have these warnings because of the risk of certain low blood cell counts.^4,5,7

Paclitaxel and docetaxel have another warning related to severe allergic reactions.^4,5,7

Paclitaxel also has a warning for potential complications that should be managed by an oncologist. Vinblastine should be given by people experienced with vinblastine and should only be given intravenously (IV). It has the potential to cause skin and tissue damage near the injection site.^4,5,7

Docetaxel has further warnings of an increased risk of:^4,5,7

• Severe side effects and/or death from toxicity in people with liver problems
• Death from toxicity in people who receive higher doses
• Death from toxicity in people previously treated with platinum-based drugs receiving docetaxel alone at a higher dose
• Severe fluid retention

Also, cancers can become resistant to chemotherapy drugs. This means that cancer cells adapt to the drugs and are no longer affected by them, and this may occur in some people with lung cancer. Taking a combination of drugs may help lower the risk of resistance.¹

These are not all the possible side effects of mitotic inhibitors. Talk to your doctor about what to expect when taking these drugs. You should also call your doctor if you have any changes that concern you when taking a mitotic inhibitor.

Other things to know

Mitotic inhibitors are delivered into a vein through an intravenous (IV) line. You may receive them as an infusion over a few hours depending on the specific medicine. You may get infusions each week or every few weeks. Talk to your doctor about your treatment schedule.¹

Before beginning treatment for lung cancer, tell your doctor about all your health conditions and any other drugs, vitamins, or supplements you take. This includes over-the-counter drugs. Make sure to tell your doctor about:^4-7

• Liver or heart problems
• Any allergies
• Pregnancy or plans to become pregnant
• Breastfeeding or plans to breastfeed