Coding Code Description CPT
81205 BCKDHB (branched-chain keto
acid dehydrogenase E1, beta polypeptide) (eg, Maple syrup urine
disease) gene analysis, common variants (eg, R183P, G278S, E422X)

81206
BCR/ABL1 (t(9;22)) (eg, chronic myelogenous leukemia) translocation
analysis; major breakpoint, qualitative or quantitative

81207
BCR/ABL1 (t(9;22)) (eg, chronic myelogenous leukemia) translocation
analysis; minor breakpoint, qualitative or quantitative

81208
BCR/ABL1 (t(9;22)) (eg, chronic myelogenous leukemia) translocation
analysis; other breakpoint, qualitative or quantitative

Introduction

A companion diagnostic test is specific type of medical test. It determines whether a person would respond to a particular drug. Only certain drugs have a companion diagnostic test. These are drugs, such as chemotherapy treatments, that usually have serious side effects. Companion diagnostic tests help doctors weigh if a drug’s benefits could be greater than its risks or side effects. Companion diagnostic tests help people who would respond to treatment get the drugs they need while avoiding unnecessary treatment and side effects among those who wouldn’t.

This policy discusses when companion diagnostic tests may be considered medically necessary.

Note: The Introduction section is for your general knowledge and is not to be taken as policy coverage criteria. The rest of the policy uses specific words and concepts familiar to medical professionals. It is intended for providers. A provider can be a person, such as a doctor, nurse, psychologist, or dentist. A provider also can be a place where medical care is given, like a hospital, clinic, or lab. This policy informs them about when a service may be covered.

Coverage Guidelines

The following coverage criteria apply to drugs with companion diagnostic tests, whenever there is not a specific medical policy covering the situation. If a drug-specific medical policy addresses the case circumstances, that policy will take precedence over this more general policy.

Medical Necessity

For drugs that have a specific companion diagnostic test, the test may be considered medically necessary when:

* The diagnostic test has been performed AND

* Test results predict that the drug will be of benefit to the patient for whom it is prescribed AND

* The drug is prescribed for a labeled indication in a patient that meets the FDA-approved criteria for prescribing it Such companion diagnostic tests may be considered medically necessary for any patient in whom use of the drug is contemplated and the test informs whether use of the drug is expected to yield benefit to that patient. Other uses of these tests are considered not medically necessary.

NOTE: Requests for approval of the drug should be accompanied by documentation of test results. In cases where the FDA has approved a drug with a specific branded companion test, determination of medical necessity may be based on that test, or any reasonable equivalent, whether specifically named in the label or not.

Related Information

Personalized Medicine

Personalized medicine is a general term that may be used to refer to any set of strategies used to select therapeutic approaches that are tailored to specific patients. Therapies may be identified by any clinically valid means, including demographic factors, genetic, phenotypic or biochemical markers, imaging techniques, etc.

Companion Diagnostics

Companion diagnostics are specific tests used to predict responsiveness of a patient to specific drugs or other treatments. In a more restrictive sense, the term is usually used to refer to genomic, proteomic or metabolomic testing. Genetic tests may identify a single nucleotide polymorphism (SNP) or a panel of SNPs that correlate strongly with positive response.

Evaluation of Companion Diagnostics

Evidence demonstrating the value of a companion diagnostics is categorized in three stages:

Analytic validity – How accurately and reliably the test measures the genotype or other marker of interest.

Clinical validity – How consistently and accurately the test detects or predicts the intermediate or final clinical outcomes of interest.

Clinical utility – How likely the test is to significantly improve patient outcomes.

Demonstration of clinical validity is normally expected when vetting a companion diagnostic; however, clinical utility requires longer term studies and will probably not be validated for months or years following product launch.

Benefit Application

This coverage is managed through the Pharmacy benefit.

Rationale
Development of new technologies such as whole genome assay studies (GWAS) and biobanking of clinical trial tissue samples have greatly increased the potential for identifying companion diagnostics. A previously identified marker may also be found to correlate with therapeutic outcomes, such as the Philadelphia chromosome and Bcr-Abl mutation, which have been found to have a high predictive value for response to imatinib and other targeted kinase inhibitors. The intent of this policy is broadly inclusive; covering any diagnostic methodology specified in the drug’s approved labeling, regardless of whether it is a specific proprietary test or a generic one.

The completion of the human genome sequencing project a decade ago launched a period of rapid growth in the field. The impact of modern high throughput sequencing and DNA microarray chips has dramatically increased the power of genetics research and the resulting pool of information. In the past six years, more than 1000 regions of the human genome have been associated with specific traits and diseases. In this decade, commercialized specific diagnostic test and drug pairs are beginning to emerge from the pipeline and receive final FDA approval. These represent the first of a flood of such products expected to follow.

In some cases, eg, imatinib and the Bcr-Abl mutation, the pairing will be unquestionable, and review for medical necessity may prove unnecessary. In others, potential off-label uses will develop rapidly and prescriber demand may precede the corresponding scientific evidence. For instance, ivacaftor, a recently approved novel therapy for cystic fibrosis patients, acts to improve function of CFTR chloride transport channels in patients with a G551D point mutation. This is only one of over 23 identified polymorphisms that may result in cystic fibrosis. Ivacaftor is currently under investigation for use in several other mutations, but results of these studies are not yet available; however, requests for these off-label uses are already beginning to be made. This example illustrates the need to manage off-label use. With the growing number of new diagnostic/drug pairs being approved, a more generalized approach to managing utilization is required.

As genetic science advances rapidly into this field, investigators are encountering new orders of magnitude of complexity. Despite the milestones achieved since 2001, we are still far from understanding the mechanisms behind most of the diseases being studied. Given the desperation of patients and physicians faced with incurable chronic diseases, experimentation beyond the limits of evidence-based medicine is bound to occur. This policy is designed to provide a simple administrative means of ensuring that clinical practice does not outpace research.