Palbociclib (Oral)

Overview

When patients are diagnosed with cancer, their treatment will depend on the exact type of cancer they have. Patients with advanced metastatic breast cancer have cancer which has already spread to other areas of the body. Breast cancer can be categorized into two types; cancer which is hormone receptor positive and cancer which is hormone receptor negative. If patients have breast cancer which is hormone receptor positive, estrogen or progesterone could cause the tumor to grow.

In addition to this, the patient's disease will also be categorized as either HER-2 positive or HER-2 negative. HER-2 positive cancer means that the cells have tested positive for the HER-2 protein. These HER-2 proteins are receptor cells which may be present in the cells and which can promote the spread of the disease when they are activated. If patients have HER-2 negative breast cancer, it means that the HER-2 protein has not been found in the relevant cells.

If cancer spreads to a new part of the body or returns following treatment, tests should be carried out to confirm whether it is hormone receptor positive or negative and to determine whether HER-2 protein cells are present. These results can change if the cancer spreads or returns so it's vital that further tests are carried out in these situations.

When patients are diagnosed with hormone receptor positive, HER-2 negative advanced metastatic cancer, Palbociclib may be deemed an appropriate treatment. As an antineoplastic drug, Palbociclib inhibits the cyclin-dependent kinases CDK4 and CDK6. These kinases play a role in regulating the cell cycle and, when interrupted, cells cannot fully complete the growth cycle. As a result Palbociclib can help to prevent the replication and growth of cells within the body. When applied to cancer cells, it means that the spread of cancer cells is slowed down or stopped altogether.

Once the growth cycle of the cell has been disrupted, the patient's body is able to destroy it. This means that Palbociclib can help to stop the spread of cancer but can also enable the body to destroy existing cancer cells. However, it is unable to target cancer cells exclusively. As a result, healthy cells in the patient's body may also be affected by the treatment and this can cause them to suffer some side effects. Although these can be debilitating, the benefits of treatment with Palbociclib often outweigh the risk of developing side effects.

Depending on the patient's age, condition and prior treatment, Palbociclib may be used in conjunction with other medications. If women are postmenopausal, for example, they may be treated with Palbociclib and Letrozole. Alternatively, patients who have had unsuccessful hormone therapy in the past may be treated with a combination of Palbociclib and Fulvestrant.

Although advanced metastatic breast cancer can be difficult to treat, Palbociclib can help to rid the body of cancer cells and prevent the disease from spreading any further. Appropriate for use in patients with hormone receptor positive and HER-2 negative cancer, Palbociclib can increase the success of treatment and reduces the patient's symptoms.

Conditions Treated

  • Hormone receptor positive HER-2 negative advanced metastatic breast cancer

Type Of Medicine

Antineoplastic

  • Side Effects

When taking any type of medication, there is a risk that patients will experience side effects. However, anti-cancer medicines are known to cause a wide array of side effects and patients should discuss these with their physician prior to treatment.

When patients are treated with Palbociclib, they may experience the following adverse effects:

  • Diarrhea
  • Thinning of the hair or hair loss
  • Loss or lack of strength
  • Decreased appetite
  • Numbness, tingling, painful or burning sensation
  • Nausea
  • Awkwardness or unsteadiness
  • Weakness in the legs, feet or arms
  • Vomiting

Although the above symptoms can be distressing, they may not require medical treatment if they are fairly mild and are not troublesome to the patient. However, if they are severe or persistent, patients should obtain medical advice.

In addition to this, patients will need to obtain immediate medical assistance if they experience the following side effects during or following treatment with Palbociclib:

  • Tarry, black stools
  • Fever
  • Body pains or aches
  • Headache
  • Chills
  • Loss of voice
  • Cough
  • Pain in side or lower back
  • Ear congestion
  • Pale skin
  • Difficult or painful urination
  • Sneezing
  • Unusual weakness or tiredness
  • Sore throat
  • Runny or stuffy nose
  • Anxiety
  • Inflammation or swelling of the mouth
  • Unusual bruising or bleeding
  • Trouble breathing
  • Bloody nose
  • White spots, sores or ulcers in the mouth
  • Lightheadedness or dizziness
  • Chest pain
  • Hoarseness
  • Fainting
  • Sudden shortness of breath or troubled breathing
  • Fast heartbeat

Patients should also obtain medical assistance if they experience any other side effects after being treated with Palbociclib.

Dosage

Like many anti-cancer medications, Palbociclib is usually taken in cycles. Generally, patients with advanced metastatic breast cancer are instructed to take 125mg of Palbociclib once per day, for a period of 21 days. Following this, patients should have seven days without taking Palbociclib. The cycle may then be repeated, although the patientâ's dose of medication may be modified.

This dose of medication may be given in conjunction with Fulvestrant or Letrozole, if patients are receiving treatment with either of these medicines.

Patients should always take Palbociclib in accordance with their doctor's instructions. Taking too much or too little Palbociclib can have serious side effects and may affect the success of the patient's treatment. Patients may be advised to take Palbociclib and other medications at specific times. If necessary, patients should ask for assistance in drawing up a treatment schedule so that they are able to take their medications at the appropriate times.

Palbociclib is usually prescribed in capsule form and should not be broken, opened, chewed or crushed. Patients should swallow the capsule whole when taking this medicine. In general, patients are advised to take Palbociclib with food but should not consume grapefruit or grapefruit juice at any time during their treatment with this medicine.

If patients miss a dose of Palbociclib, they are usually advised to skip the missed dose completely and return to their normal treatment schedule. Patients should not attempt to take a double dose of Palbociclib, even if an earlier dose of medicine has been missed. However, patients should contact their physician or pharmacist for advice if they have missed a dose of medicine or if they are unsure how or when to take Palbociclib.

Potential Drug Interactions:

Whilst some medicines can be used at the same time, others cannot. Due to the possibility of interactions occurring, patients are not usually prescribed any of the following medicines or supplements whilst they are being treated with Palbociclib:

  • Boceprevir
  • Mitotane
  • Carbamazepine
  • Indinavir
  • Clarithromycin
  • Phenytoin
  • Cobicistat
  • Ketoconazole
  • Conivaptan
  • Nelfinavir
  • Enzalutamide
  • Nefazodone
  • Eslicarbazepine Acetate
  • Posaconazole
  • Fosphenytoin
  • Telithromycin
  • Idelalisib
  • Itraconazole
  • Ritonavir
  • Lopinavir
  • Saquinavir
  • Oxcarbazepine
  • St John's Wort
  • Rifampin
  • Telaprevir
  • Voriconazole
  • Tipranavir

As well as interacting with other prescription medicines, Palbociclib could interact with some foods, drinks, over-the-counter medicines, supplements or vitamins. Whilst receiving treatment with this medication, patients should not eat or drink:

  • Grapefruit, grapefruit juice or anything containing grapefruit

Patients should also tell their physician if they are using any over-the-counter medicines, supplements or vitamins before they start taking Palbociclib. In addition to this, patients will need to obtain medical advice before using any new over-the-counter medicines, vitamins or supplements once they have started taking Palbociclib. If patients need additional medication to manage their side effects during treatment, they should seek advice from their physician.

Warnings

If patients have any other health problems or a history of certain health problems, it may affect the suitability of Palbociclib as a treatment. The following conditions can be particularly relevant if treatment with Palbociclib is being prescribed:

  • Blood clots in the lungs (Pulmonary embolism)
  • Infection

The safety of Palbociclib when used on pediatric patients has yet to be confirmed. Due to this, pediatric patients are not usually prescribed Palbociclib for the treatment of any condition.

During treatment with Palbociclib, patients may have temporarily low white blood cells count and this can leave them prone to infections. If possible, patients should avoid people who they know are unwell and should obtain immediate medical attention if they start to exhibit any symptoms of an infection, such as:

  • Pain in lower back or side
  • Fever
  • Hoarseness
  • Chills
  • Difficult or painful urination
  • Cough

If patients display any of the following symptoms during treatment with Palbociclib, it may indicate that they are suffering from a pulmonary embolism:

  • Troubled breathing
  • Sudden, sharp chest pain
  • Rapid breathing
  • Rapid heartrate

A pulmonary embolism is a medical emergency and patients will need to obtain urgent and immediate medical treatment if they experience the above symptoms.

If patients use Palbociclib when pregnant, it could cause harm to the unborn fetus. Due to this, Palbociclib should not be prescribed to pregnant patients unless they are aware of the risks and the benefits of treatment outweigh the potential harm which could be caused.

During treatment and for at least three weeks afterwards, patients should use an effective form of birth control and should not attempt to conceive. If male patients are prescribed Palbociclib, they should also use effective birth control during treatment and for at least three months afterwards. If male patients impregnate a partner during this time, Palbociclib could cause the fetus to develop birth defects.

If a patient becomes pregnant or impregnates a partner whilst taking Palbociclib or soon after taking Palbociclib, they should contact their physician immediately.

It is not known whether Palbociclib can be transmitted to an infant via breastmilk and, if so, what level of harm it could cause. Due to this, patients are generally advised not to breastfeed during treatment with Palbociclib and should avoid breastfeeding for some time after. Patients should always obtain medical advice before breastfeeding if they have been treated with Palbociclib.

Palbociclib may cause patients to experience fertility issues in the future and some male patients have become infertile after receiving treatment with this medication. If the patient plans to have children in the future or is unsure whether they want to have children in the future, they should discuss this with their physician before beginning treatment with Palbociclib.

Before patients start taking Palbociclib, they should inform their doctor if they have any known allergies. If patients experience an allergic reaction whilst being treated with this medicine, they will require emergency medical treatment. The symptoms of an allergic reaction can include:

  • Difficulty breathing
  • Wheezing
  • Difficulty swallowing
  • Itching
  • Hives
  • Rash on the skin
  • Hoarseness
  • Swelling of the hands, face, lips, tongue, throat or mouth

Storage

When storing Palbociclib, patients should follow the manufacturer's guidelines and ensure that their medication is kept in a safe place. It is particularly important that children and/or pets cannot gain access to medication in the home.

Generally, Palbociclib should be kept in a closed container at room temperature but should be protected from moisture, heat and light.

If the medicine reaches its use-by date or the patient is advised to stop taking it, the medicine will need to be disposed of carefully. Patients should contact their pharmacist or doctor's office and use a specialist medicine disposal service.

Summary

Whilst advanced metastatic breast cancer remains a difficult condition to treat, physicians can increase the success of treatments by determining the exact type of cancer affecting the patient. Hormone receptor positive and negative cancers can be triggered by different things, for example, and are likely to respond differently to certain treatments. By categorizing the patient's condition in this way, doctors can determine which type of treatment and medication is likely to be most successful in treating the cancer.

If patients are diagnosed with hormone receptor positive HER-2 negative advanced metastatic cancer, Palbociclib can be effective in preventing the disease from spreading and enabling the body to destroy existing cancer cells. When used alongside other anti-cancer medications, Palbociclib can help to prolong the patient's life, reduce the patient's symptoms and increase the body's ability to rid itself of the existing cancer cells.