How Do Antineoplastic Protein Synthesis Inhibitors Work?

Antineoplastic protein synthesis inhibitors are a class of drugs used to treat adults with chronic or accelerated phase chronic myeloid leukemia (CML; a type of cancer of the white blood cells) who have already been treated with at least two other medications for CML and can no longer benefit from these medications or cannot take these medications because of side effects.

CML is a rare, slow-growing type of cancer of the bone marrow—the spongy tissue inside bones where blood cells are made. CML causes an increased number of white blood cells in the blood.

Signs and symptoms may include:

• Bone pain
• Easy bleeding
• Feeling full after eating a small amount of food
• Feeling exhausted or tired
• Fever
• Weight loss without trying
• Loss of appetite
• Pain or fullness below the ribs on the left side
• Excessive sweating during sleep (night sweats)

The only drug belonging to this class is “omacetaxine” synthesized from cephalotaxine, which is an extract from the leaves of the plant, Cephalotaxus species. Protein synthesis inhibitor works by slowing down or stopping the growth or proliferation of cells by disrupting the processes that lead directly to the generation of new proteins.

Protein synthesis inhibitors are administered as a liquid to be injected under the skin in the thigh or stomach area typically twice a day for 7 to 14 days.

Protein synthesis inhibitors work in the following ways:

They inhibit different stages of translation of the bacterial mRNA into proteins.

This inhibition is a result of interruption of peptide chain elongation, blocking the “A” site of ribosomes and misreading of the genetic code or the prevention of the attachment of oligosaccharide side chains to glycoproteins.

Antineoplastic protein synthesis inhibitors are indicated for the treatment of chronic or accelerated phase chronic myeloid leukemia with resistance and/or intolerance to two or more tyrosine kinase inhibitors.

Some of the common side effects include:

• Nausea
• Vomiting
• Constipation
• Diarrhea
• Abdominal pain
• Headache
• Tiredness/weakness
• Joint/back pain
• Loss of appetite
• Pain, redness, swelling, hardness, or itching at the injection site

Other rare side effects include:

• Dizziness 
• Fatigue
• Hair loss
• Anemia (low red blood cell count)
• Insomnia 
• Shortness of breath
• Chills, sore throat, fever, or cough
• Thrombocytopenia (low blood platelet count)
• Peripheral edema (swelling of lower legs or hands)
• Epistaxis (bleeding from the nose)
• Hyperglycemia (high blood glucose level)

Information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

Generic and brand names of antineoplastic protein synthesis inhibitors include:

• Omacetaxine
• Synribo