Two novel imaging agents and 6 clinical assays for use in cancer care gained the FDA’s approval in 2016, marking advances in the diagnostic field during a relatively slow year for new oncology drugs.
The imaging agents are categorized as new molecular entities (NMEs), which the FDA defines as products that contain a previously unapproved active ingredient either as part of a single drug or in a combination regimen; in some instances, these ingredients may be closely related to agents that have gained prior approvals. Overall, the agency approved 7 NMEs in oncology during 2016.
The novel diagnostics that passed muster for US marketing are both radioactive positron emission tomography (PET) agents. In May, the FDA approved fluciclovine F 18 (Axumin) for PET imaging in men with suspected prostate cancer recurrence based on elevated blood prostate-specific antigen levels following prior treatment. Blue Earth Diagnostics Ltd, the company that developed the product, said it is the first such F 18 imaging agent to gain an indication in that clinical setting.
In June, the FDA approved gallium Ga 68 dotatate (Netspot) for localization of somatostatin receptor–positive neuroendocrine tumors in adult and pediatric patients. Ga 68 dotatate positron-emitting analogue of somatostatin that binds to such receptors, is marketed by Advanced Accelerator Applications USA, Inc.
In terms of new assays, the FDA approved following tests in 2016:
Vysis CLL FISH Probe Kit
The Vysis CLL FISH Probe Kit was approved as a companion diagnostic to venetoclax (Venclexta), a BCL-2 inhibitor intended for patients with chronic lymphocytic leukemia (CLL) following at least 1 prior therapy. The kit, which contains 5 reagents sufficient to process 20 assays, also can be used to assess untreated patients.
The test detects deletion of the locus-specific identifier TP53 gene, found on the short arm of chromosome 17p, via fluorescence in situ hybridization (FISH) in peripheral blood specimens from patients with B-cell CLL to identify patients who could be eligible for treatment with venetoclax.
In untreated patients, the assay may be used to dichotomize CLL based on genotype group, and may be used as an aid in determining disease prognosis in combination with additional biomarkers, morphology, and other clinical information. However, the test is not intended for monitoring residual disease.
The Vysis CLL FISH Probe Kit was approved in April 2016, and is manufactured by Abbott Molecular.
Ventana PD-L1 (SP142) Assay
The Ventana PD-L1 (SP142) assay, approved as a complementary diagnostic for atezolizumab (Tecentriq), assesses whether patients who have bladder cancer have PD-L1 in their tumor tissue. This will help practitioners treating patients with bladder cancer decide if atezolizumab, a PD-L1 inhibitor, is the best treatment option after platinum-based chemotherapy.
The assay takes a small tissue sample of the patient’s tumor and stains the sample to detect the presence (or absence) of PD-L1-expression. Patients with either a positive or negative test result can benefit from the drug atezolizumab; however, patients whose bladder cancer has high PD-L1 may have greater benefit to atezolizumab than in patients whose bladder cancer does not have PDL1.
The Ventana PD-L1 (SP142) assay was approved in May 2016, and is manufactured by Ventana Medical Systems, Inc.
cobas EGFR Mutation Test
The cobas EGFR Mutation Test v2 was approved for use with plasma samples as a companion diagnostic for the non–small cell lung cancer (NSCLC) drug erlotinib (Tarceva). This is the first FDA approval of a liquid biopsy test as an aid in clinical decisions, and makes the cobas EGFR Mutation Test v2 the only FDA-approved test for the detection of the EGFR
gene in DNA derived from plasma or tumor tissue.
With this test, the presence of specific NSCLC mutations [exon 19 deletion or exon 21 (L858R) substitution mutations] detected in patients’ blood samples aids in selecting patients who may benefit from treatment with erlotinib. However, if such mutations are not detected in the blood, then a tumor biopsy should be performed to determine if the mutations are present. If the test shows positive results, it may benefit patients who may be too ill or unable to provide a tumor specimen for EGFR
The cobas EGFR Mutation Test v2 was approved in June 2016, and is manufactured by Roche Molecular Systems.
QuantideX qPCR BCR-ABL IS Kit
The FDA has given marketing approval to the first nucleic acid–based test for quantifying BCR-ABL1 fusion transcripts as a tool for monitoring patients with chronic myeloid leukemia (CML) who are receiving tyrosine kinase inhibitor therapies directed at the mutation.
The QuantideX qPCR BCR-ABL IS Kit, which uses whole blood specimens, demonstrated a high level of analytical sensitivity in human RNA. The company said the test could detect BRC-ABL1 RNA in ≥95% of patients at MR 4.7 (log molecular reduction from 100% IS).