Drugs Xagena
The FDA ( Food and Drug Administration ) has granted accelerated approval to Lynparza ( Olaparib ), a new drug treatment for women with advanced ovarian cancer associated with defective BRCA genes, as detected by an FDA-approved test.
Ovarian cancer forms in the ovary, one of a pair of female reproductive glands where ova, or eggs, are formed.
The National Cancer Institute ( NCI ) estimates that 21,980 American women will be diagnosed with and 14,270 will die from ovarian cancer in 2014.
Lynparza is a poly ADP-ribose polymerase ( PARP ) inhibitor that blocks enzymes involved in repairing damaged DNA. It is intended for women with heavily pretreated ovarian cancer that is associated with defective BRCA genes.
The FDA approved Lynparza with a genetic test called BRACAnalysis CDx, a companion diagnostic that will detect the presence of mutations in the BRCA genes ( gBRCAm ) in blood samples from patients with ovarian cancer.
The BRCA genes are involved with repairing damaged DNA and normally work to suppress tumor growth.
Women with mutations resulting in defective BRCA genes are more likely to get ovarian cancer, and it is estimated that 10 to 15% of all ovarian cancer is associated with these hereditary BRCA mutations.
The FDA evaluated the BRACAnalysis CDx’s safety and efficacy under the agency’s premarket approval pathway used for high-risk medical devices. Until now, the manufacturer, a clinical laboratory, had been marketing this test, although not specifically for use as a companion diagnostic, without FDA approval as a laboratory developed test ( LDT ), which is a test that is designed, manufactured and used in a single laboratory.
The new test is approved as a companion diagnostic, specifically to identify patients with advanced ovarian cancer who may be candidates for treatment with Lynparza.
The FDA’s approval of the BRACAnalysis CDx is based on data from the clinical study used to support approval of Lynparza. Blood samples from clinical trial participants were tested to validate the test’s use for detecting BRCA mutations in this population.
Lynparza’s efficacy was examined in a study where 137 participants with gBRCAm-associated ovarian cancer received the drug. The study was designed to measure objective response rate ( ORR ), or the percentage of participants who experienced partial shrinkage or complete disappearance of the tumor.
Results showed 34% of participants experienced ORR for an average of 7.9 months.
Common side effects of Lynparza included nausea, fatigue, vomiting, diarrhea, distorted taste ( dysgeusia ), dyspepsia, headache, decreased appetite, common cold-like symptoms ( nasopharyngitis ), cough, joint paint ( arthralgia ), musculoskeletal pain, muscle pain ( myalgia ), back pain, rash ( dermatitis ) and abdominal pain.
Serious side effects included the development of myelodysplastic syndrome, a condition where the bone marrow is unable to produce enough functioning blood cells; acute myeloid leukemia, a bone marrow cancer; and lung inflammation.
The most common laboratory abnormalities were increased creatinine, increased average volume of red blood cells ( mean corpuscular volume elevation ), decreased red blood cell count ( hemoglobin ), decreased white blood cell count ( lymphocytes and neutrophils ) and decreased platelet levels.
In June, Lynparza was reviewed by the FDA’s Oncologic Drugs Advisory Committee for potential use as maintenance therapy ( treatment given to keep cancer from returning ). The Committee advised the agency in a vote of 11 to 2 that the data did not support Lynparza’s accelerated approval for this use. After the meeting, the company submitted additional information supporting Lynparza’s use for a different use: in patients with gBRCAm-associated ovarian cancer who have received three or more chemotherapy treatments.
The FDA has approved Lynparza under the agency’s accelerated approval program, which allows approval of a drug to treat a serious or life-threatening disease based on clinical data showing the drug has an effect on a surrogate endpoint reasonably likely to predict clinical benefit to patients. This program provides earlier patient access to promising new drugs while the company conducts confirmatory clinical trials. Lynparza’s application was reviewed under the FDA’s priority review program, which provides for an expedited review of drugs that are intended to treat a serious disease or condition and, if approved, would offer significant improvement compared to marketed products.
BRACAnalysis CDx’s application was reviewed under the FDA’s priority review program for devices, which provides for priority review of devices that meet certain criteria, including that the devices are intended to treat or diagnose a life-threatening or irreversibly debilitating disease or condition and, if approved, would offer significant, clinically meaningful advantages compared to marketed products. ( Xagena )
Source: FDA, 2014
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