This said, the FDA just expanded the approved use of Olaparib Tablets (Lynparza) to include the treatment of patients with certain types of breast cancer that have spread (metastasized) and whose tumors have a specific inherited (germline) genetic mutation, making it the first drug in its class (PARP inhibitors) approved to treat breast cancer, and it is the first time any drug has been approved to treat certain patients with metastatic breast cancer who have a BRCA gene mutation. Patients are selected for treatment with Olaparib Tablets (Lynparza) based on an FDA-approved genetic test, called the BRACAnalysis CDx.
The class of drugs (PARP inhibitors) has previously been used to treat advanced, BRCA-mutated ovarian cancer and shows now efficacy in treating certain types of BRCA-mutated breast cancer. The current approval of Olaparib Tablets (Lynparza) demonstrates the paradigm of developing drugs that target the underlying genetic causes of a cancer, which often apply across cancer types and their origin within the body.
Breast cancer is the most common form of cancer in the United States. The National Cancer Institute at the National Institutes of Health estimates approximately 252,710 women will be diagnosed with breast cancer this year, and 40,610 will die of the disease. Approximately 20-25 percent of patients with hereditary breast cancers and 5-10 percent of patients with any type of breast cancer have a BRCA mutation. BRCA genes are involved with repairing damaged DNA and normally work to prevent tumor development. However, mutations of these genes may lead to certain cancers, including breast cancers.
Olaparib Tablets (Lynparza) is a PARP (poly ADP-ribose polymerase) inhibitor that blocks an enzyme involved in repairing damaged DNA. By blocking this enzyme, DNA inside the cancerous cells with damaged BRCA genes may be less likely to be repaired, leading to cell death and possibly a slow-down or stoppage of tumor growth. Olaparib Tablets (Lynparza) was first approved by the FDA in 2014 to treat certain patients with ovarian cancer and is now indicated for the treatment of patients with germline breast cancer susceptibility gene (BRCA) mutated, human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer, who have been previously treated with chemotherapy. Patients with hormone receptor (HR)-positive breast cancer should have been treated with a prior hormonal (endocrine) therapy or be considered inappropriate for endocrine treatment.
The FDA also expanded the approval of the BRACAnalysis CDx, an approved companion diagnostic test to Olaparib Tablets (Lynparza), to include the detection of BRCA mutations in blood samples from patients with breast cancer.
The efficacy of Olaparib Tablets (Lynparza) for the treatment of breast cancer was based on a randomized clinical trial of 302 patients with HER2-negative metastatic breast cancer with a germline BRCA mutation. The trial measured the length of time the tumors did not have significant growth after treatment (progression-free survival). The median progression-free survival for patients taking Olaparib Tablets (Lynparza) was 7 months compared to 4.2 months for patients taking chemotherapy only.
As always, therapies come with a price in the form of adverse drug reactions (ADRs). Thus, common side effects of Olaparib Tablets (Lynparza) include low levels of red blood cells (anemia), low levels of certain white blood cells (neutropenia, leukopenia), nausea, fatigue, vomiting, common cold (nasopharyngitis), respiratory tract infection, influenza, diarrhea, joint pain (arthralgia/myalgia), unusual taste sensation (dysgeusia), headache, indigestion (dyspepsia), decreased appetite, constipation and inflammation and sores in the mouth (stomatitis).
Severe side effects of Olaparib Tablets (Lynparza) include development of certain blood or bone marrow cancers (myelodysplastic syndrome/acute myeloid leukemia) and inflammation in the lungs (pneumonitis). Olaparib Tablets (Lynparza) can cause harm to a developing fetus; women should be advised of the potential risk to the fetus and to use effective contraception. Women taking Olaparib Tablets (Lynparza) should not breastfeed as it could cause harm to a newborn baby.