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== Analyte Specific Reagent (ASR) ==


Code of Federal Regulations Title 21 (21CFR809.30) states that ASRs may only be sold to: IVD manufacturers, CLIA labs capable of high-complexity testing, and organizations that use the reagents for non-clinical uses.
==Abbreviations==
The table below is a list of commonly used abbreviations throughout this wiki.


There are 3 classes of ASRs, I, II, and III. The analytical and performance characteristics of Class I ASRs are not established by the FDA, and for Class II and III ASRs are only established as a component of a cleared test.  Because ASRs do not generally require full FDA pre-market review, they can be developed more quickly for less money.  But they are not sold as complete diagnostics - instead, CLIA labs purchase ASRs to use in diagnostic tests they develop internally.
{| class="wikitable" border=1 align="center"
|+ '''Abbreviations'''
!Abbreviation !! Definition
|-
|'''510(k)/PMA'''
|[[Pre-Market Notification]]
|-
|'''ASR'''
|[[Analyte Specific Reagent]]
|-
|CLIA
|[[Clinical Laboratory Improvement Amendments Act]]
|-
|CMS
|[[Centers for Medicaid and Medicare Services]]
|-
|FDA
|[[Food and Drug Administration]]
|-
|IVDs
|[[''In Vitro'' Diagnostics]]
|-
|IVDMIAs
|[[''In Vitro'' Diagnostic Multi-Variate Assays]]
|-
|LDTs
|[[Laboratory Developed Tests]]
|}


"ASRs were initially introduced to improve the availability of immunohistochemical stains for which manufacturers had not sought FDA market clearance because the cost was too high for the revenues that would come from such products. The ASR regulatory path has become the chosen commercialization route for many molecular tests for similar cost-versus-revenue reasons. The minimal regulatory burden involved in releasing tests as ASRs allowed for a lucrative market, even in the earliest stages of this market sector." [3]
==Analyte Specific Reagent (ASR)==


Examples of ASRs:
Generally, the term “analyte specific reagent” or “ASR” is used to describe a component of a genetic test that is commonly sold or used with a “testing kit.”  Scientists use the term to describe certain types of biochemical, chemical, or other substances, and occasionally devices, that are used to conduct a test at a laboratory.  However, because the FDA regulates the use and sale of ASRs to some extent, the definition used within the FDA regulations is also commonly used in practice.   
* Microarrays
* Antibodies
* Algorithms for interpreting IVDMIAs?


Although ASRs are often defined in layman’s terms as the “building blocks” or “active ingredients” of a test, it's helpful to understand how genetic tests are brought to market.  Genetic tests tend to be developed either as a "Testing Kit" which is commercially sold to laboratories who conduct the tests, or as a "Laboratory Developed Test" (or LDT), which is developed by a laboratory solely for "in-house use," and is not commercially sold to other entities.
 
:'''''Testing Kits:''''' When a device manufacturer develops a genetic test and sells it to a laboratory who will collect the specimen and actually conduct the test, they sell the test as a "kit" that includes all the necessary ASRs, as well as instructions on how to conduct the test.


Can non-CLIA customers purchase ASRs for non-clinical use?
:'''''LDTs:''''' when a testing laboratory develops its own genetic test, including the ASRs, and uses the test (also called a in-house, home brew, or LDT) only at their testing laboratory and does not commercially sell the test to anyone else. 


What is the distinction between the three classes of ASRs?
The differences of how the test is developed and sold is important for regulatory reasons.  Different federal regulations apply to the sale and use of ASRs.  This depends on whether the ASR is being used soley for in-house use at a laboratory (i.e., LDTs), or if it is being sold commercially by testing manufacturers as part of a kit. 


* [1] http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?FR=809.30
For regulatory purposes, the FDA defines ASRs as:
* [2] Phillips, K.a., Van Bebber, S. & Issa, A.M., 2006. Diagnostics and biomarker development: priming the pipeline. Nature reviews. Drug discovery, 5(6), 463-9
:“antibodies, both polyclonal and monoclonal, specific receptor proteins, ligands, nucleic acid sequences, and similar reagents which, through specific binding or chemical reaction with substances in a specimen, are intended for use in a diagnostic application for identification and quantification of an individual chemical substance or ligand in biological specimens.”<ref> FDA Regs., Definition of Analyte-Specific Reagents, 21 C.F.R. § 864.4020.</ref>
* [3]  Kalorama Information (Rosen). Diagnostic Test Service Commercialization: A Roadmap to Diagnostics in the 21st Century. (2008), pg 10.


== Clinical Laboratory Improvement Amendments (CLIA) ==
For more information on the regulatory distinctions of ASRs see our wiki page on [[Diagnostic_Kits/USA_Regulation|U.S. Regulation]].
Passed by Congress in 1988, CLIA established "quality standards for all laboratory testing to ensure the accuracy, reliability and timeliness of patient test results regardless of where the test was performed. A laboratory is defined as any facility which performs laboratory testing on specimens derived from humans for the purpose of providing information for the diagnosis, prevention, treatment of disease, or impairment of, or assessment of health."[1]


The stringency of CLIA regulations increase with the complexity of the test being performed.  Three categories have been established: '''waived complexity, moderate complexity, and high complexity'''.
'''''See Also:'''''
* [http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?FR=809.30 FDA Regulations on ASRs]
* [http://en.wikipedia.org/wiki/Analyte_specific_reagent Wikipedia Definition]
* [http://www.mddionline.com/article/fda%E2%80%99s-regulation-analyte-specific-reagents Medical Device Industry.com]
* [http://www.labtestsonline.org/understanding/features/market-5.html How Lab Tests Get to Market]
* [http://www.aacc.org/resourcecenters/resource_topics/tests/pages/default.aspx AACC.org Resources]


The CMS implements CLIA (and receives certification and inspection fees from labs), the CDC is responsible for CLIA studies, and the FDA is responsible for test categorization.
==Clinical Laboratory Improvement Amendments (CLIA)==
''See [[Diagnostic_Kits/USA_Regulation_Review#CMS_Regulations|CMS Regulations]]''


"To enroll in the CLIA program, laboratories must first register by completing an application, pay fees, be surveyed, if applicable, and become certified."[1]
==Analytical & Clinical Validity & Utility==
One problem that is repeatedly encountered in literature is how to quantify the proficiency and usefulness of a particular genetic test. At present, there are no universally established standards for genetic tests to determine proficiency and usefulness by a regulatory body.  However, Professional Associations, Laboratory Accreditation Organizations, Policy Groups and Patient Advocacy Organizations all seem to agree that the follow criteria are important when addressing these questions.      


[1] http://www.cms.hhs.gov/CLIA/07_Program_Descriptions_Projects.asp<br>
:'''Analytical Validity:''' refers to the level of accuracy and consistency with which a particular genetic characteristic, such as a DNA sequence variant, chromosomal deletion or biochemical indicator, can be identified in a given laboratory test.  
[2] http://www.fda.gov/cdrh/CLIA/


== Clinical Utility ==
:'''Clinical Utility:''' defines the risks and benefits associated with the introduction of a test into practice, including the impact of positive and negative test results on health outcomes, cost-effectiveness, and ethical, legal and social issues associated with test use.
"Clinical utility defines the risks and benefits associated with the introduction of a test into practice, including the impact of positive and negative test results on health outcomes, cost-effectiveness, and ethical, legal and social issues associated with test use." [1]


[1] http://www.cdc.gov/genomics/about/reports/2003/chap10.htm
:'''Clinical Validity:''' refers to the accuracy of a test when used to identify the presence of disease or predict a patient's clinical status.  


== In-Vitro Diagnostic (IVD) ==
'''''See Also:'''''
In-Vitro diagnostics can be categorized into 5 types: General (Clinical) chemistry, Immunochemistry, Hematology/Cytology, Microbiology/Infectious Disease, & Molecular, Genomic, Proteomic, & Metabolomic (Omics).
* [http://www.nature.com/nrg/journal/v5/n12/glossary/nrg1495_glossary.html]
* [http://www.cdc.gov/genomics/about/reports/2003/chap10.htm]
* [http://www.dnapolicy.org/policy.issue.php?action=detail&issuebrief_id=10]
* [http://www.genome.gov/10002403]
* [http://www.genengnews.com/gen-articles/successful-genetic-tests-are-predicated-on-clinical-utility/2544/]


'''What they are not''': Imaging (CAT/MRIs, ultrasounds) or In-Vitro: (assess health status inside of body or measure body functions as they occur, like a heart rate monitor, blood pressure, temperature)
==Genetics vs Genomics==


Examples:
* cholesterol test, urinalysis strips (Clinical Chemistry)
===Genetics===
* blood count, pap smear (Hematology/Cytology)
Genetics is a term that refers to the study of genes and their role in inheritance - the way certain traits or conditions are passed down from one generation to another. Genetics involves scientific studies of single genes and their effects. Genes (units of heredity) carry the instructions for making proteins, which direct the activities of cells and functions of the body. Genes influence traits such as hair and eye color as well as health and disease development. Genetics determines much (but not all) of a person's appearance and health status, but environmental differences also play a part. Examples of single gene disorders that would be considered as "genetics" include cystic fibrosis and PKU (phenylketonuria).
* Strep test, SARS blood screening (Microbiology)
* PSA test for prostate cancer, HIV antibody testing (Immunochemistry)
* SARS PCR assay, HIV viral load, CYP450 diagnostics, BRCA cancer screening (Omics)


FDA Definition: "''In vitro diagnostic products are those reagents, instruments, and systems intended for use in diagnosis of disease or other conditions, including a determination of the state of health, in order to cure, mitigate, treat, or prevent disease or its sequelae. Such products are intended for use in the collection, preparation, and examination of specimens taken from the human body.'' [21 CFR 809.3]" [1]
'''''See Also:'''''
*[http://www.cdc.gov/genomics/public/index.htm CDC.gov's page on Genomics and Health]
*[http://www.cdc.gov/genomics/resources/index.htm CDC.gov's links to Genomic Resources]
*[http://www.genome.gov/19016904 Genome.gov FAQ's]


"Principal uses include primary risk assessment (including predictive and early disease identification applications), diagnosis, secondary risk assessment (prognosis), drug selection and treatment targeting applications and disease/condition monitoring and management." [4]
===Genomics===
Genomics is a relatively new term that describes the study of all of a person's genes including interactions of those genes with each other and the person's environment. Genomics involves the scientific study of complex diseases such as heart disease, asthma, diabetes and cancer because they are caused more by a combination of genetic and environmental factors. Genomics is offering new possibilities for therapies and treatment of some diseases, as well as new diagnostic methods. The major tools and methods related to genomics studies are bioinformatics, genetic analysis, measurement of gene expression, and determination of gene function.  


=== Regulation ===
'''''See Also:'''''
"There are essentially two kinds of tests: those that are manufactured and sold in volume as kits to laboratories and those that are developed within a particular laboratory (called laboratory-developed assays). In each case, their development and entry into the market - that is, their use on patient specimens - is governed by sets of rules that ensure their accuracy and reliability." [2]  Laboratory-developed assays often depend on Analyte-Specific Reagents (ASRs), which are regulated less-stringently than complete diagnostic kits. However, ASRs must be used in CLIA-certified labs.
*[http://www.cdc.gov/genomics/gtesting/index.htm CDC.gov's page on Genetics]
*[http://www.genome.gov/19016904 Genome.gov FAQ's]


See Pre-Market Review and CLIA.
==Typology of Genetic Tests==
''See [[Diagnostic_Kits/USA_Regulation_Review#Regulatory_Classifications_of_Genetic_Tests|Regulatory Classifications of Genetic Tests]]''


=== The Diagnostic Process ===
==In-Vitro Diagnostic Multivariate Index Assay (IVDMIAs)==
The primary components of the diagnostic process: samples, controls, instruments, and accessories. [3]
''See [[Diagnostic_Kits/USA_Regulation_Review#Regulatory_Classifications_of_Genetic_Tests|Regulatory Classifications of Genetic Tests]]''


* [1] http://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/IVDRegulatoryAssistance/ucm123682.htm
* [2] http://www.labtestsonline.org/understanding/features/market.html
* [3] Goodman et al. The Value of Diagnostics: Innovation, Adoption and Diffusion Into Health Care.  (2005) pp. 14-15
* [4] ibid pg. 40
== Diagnostic kit ==
== Direct Access Testing (DAT) ==
== Direct Access Testing (DAT) ==
"As with home testing, direct access testing (DAT) has been growing in popularity over the past few years. Currently, 34 states permit consumers to order their own lab tests - without a medical order from their health care provider. Also known as patient authorized testing, DAT is a reflection of Americans' focus on health and preventive medicine, offering the opportunity for patients to take a more active role in their own health care.
"As with home testing, direct access testing (DAT) has been growing in popularity over the past few years. Currently, 34 states permit consumers to order their own lab tests - without a medical order from their health care provider. Also known as patient authorized testing, DAT is a reflection of Americans' focus on health and preventive medicine, offering the opportunity for patients to take a more active role in their own health care.
Line 83: Line 113:


== Direct to Consumer (DTC) ==
== Direct to Consumer (DTC) ==
IVDs sold directly to consumers who operate the tests themselves.  Also known as Over the counter (OTC) or home-based kits.  Some DTC products may also be considered [[Diagnostic_Kits/Glossary#Direct_Access_Testing_.28DAT.29|DAT]] products.  In these cases, the consumer collects the sample themselves with a sampling kit and mails it away for analysis in a commercial lab.  In most DTC IVDs, such as home pregnancy tests or blood glucose tests, the sample collection and analysis happens together in the home.
IVDs sold directly to consumers who operate the tests themselves.  Also known as Over the counter (OTC) or home-based kits.  Some DTC products may also be considered [[Diagnostic_Kits/Glossary#Direct_Access_Testing_.28DAT.29|DAT]] products.  In these cases, the consumer collects the sample themselves with a sampling kit and mails it away for analysis in a commercial lab ([http://www.dnadirect.com/ DNAdirect]'s products work this way).  In most DTC IVDs, such as home pregnancy tests or blood glucose tests, the sample collection and analysis happens together in the home.


"While the majority of diagnostic tests are conducted by clinicians and laboratory personnel, individual consumers also purchase diagnostics for private use in their homes. The market for home testing devices expanded from $1.19 billion in 1994 to $4.8 billion in 2002. Among home testing devices approved by the FDA are those that measure cholesterol levels, glucose levels, vaginal pH levels, blood clotting time (for patients on blood thinning drugs such as warfarin) and the presence of fecal occult blood (for detecting colon cancer). The FDA also has approved home testing devices that test for hepatitis C virus (HCV) and HIV, as well as for detecting menopause, pregnancy and drug abuse. The most frequently used home testing devices include blood glucose monitors for diabetics, pregnancy tests and cholesterol tests." [1]
"While the majority of diagnostic tests are conducted by clinicians and laboratory personnel, individual consumers also purchase diagnostics for private use in their homes. The market for home testing devices expanded from $1.19 billion in 1994 to $4.8 billion in 2002. Among home testing devices approved by the FDA are those that measure cholesterol levels, glucose levels, vaginal pH levels, blood clotting time (for patients on blood thinning drugs such as warfarin) and the presence of fecal occult blood (for detecting colon cancer). The FDA also has approved home testing devices that test for hepatitis C virus (HCV) and HIV, as well as for detecting menopause, pregnancy and drug abuse. The most frequently used home testing devices include blood glucose monitors for diabetics, pregnancy tests and cholesterol tests." [1]
Line 91: Line 121:
== Reference Lab ==
== Reference Lab ==


"When diagnostic capabilities are needed beyond those provided in hospitals and physician practices, analysis is conducted in reference labs. While reference labs comprise only 2.8% of all clinical labs within the US, these facilities are responsible for 32% of the diagnostic industry’s revenue, due to their focus on processing large volumes of diagnostic tests for a broad client base.  Reference labs generally perform both routine testing and esoteric testing. The largest reference labs may conduct more than 4,400 different types of tests, ranging from high-throughput routine tests (e.g., routine culture, cholesterol tests, Pap smears) to complex or specialized diagnostic tests for Lyme’s disease, cancer, cardiovascular disease and HIV." [4]
"When diagnostic capabilities are needed beyond those provided in hospitals and physician practices, analysis is conducted in reference labs. While reference labs comprise only 2.8% of all clinical labs within the US, these facilities are responsible for 32% of the diagnostic industry’s revenue, due to their focus on processing large volumes of diagnostic tests for a broad client base.  Reference labs generally perform both routine testing and esoteric testing. The largest reference labs may conduct more than 4,400 different types of tests, ranging from high-throughput routine tests (e.g., routine culture, cholesterol tests, Pap smears) to complex or specialized diagnostic tests for Lyme’s disease, cancer, cardiovascular disease and HIV." [1]
 
"Reference labs are usually private, commercial facilities that do high volume routine and specialty testing. Most of the tests performed are referred from physician’s offices, hospitals and other health care facilities (e.g., nursing homes and other facilities). While most hospitals try to do as many tests as possible in-house, reference labs are used for specialized tests that are ordered only occasionally or that require specialized equipment." [1]
 
'''Market Share'''<br>
"The major national reference labs including Quest, LabCorp, Specialty/Ameripath, Mayo and others account for at least 60% of the market for esoteric test services. The remaining 40% is shared by a group of some 3000 small, local market laboratories. The major reference labs have built a comprehensive menu of specialized test services and continue to expand their offerings via collaborations with leading medical research centers. They offer a huge presence in the market and manage distribution networks that touch just about every medical specialty. Thus many CLIA-registered company sponsored test services avail themselves of the marketing resources offered by the national reference labs." [2]
 
'''Margins & Growth'''<br>
The bulk of reference lab test services cover highly commoditized routine tests. Here  the margins are low because labs compete for clients based on cost per test.  As lab  medicine evolved with the development of personalized medicine, the complexity of  testing has increase significantly.
 
New technologies are fueling faster growth in segments such as analysis of biopsy tissue, protein biomarkers and genetic testing.  LabCorp and Quest have developed tests  in these areas, but most have been developed by smaller reference labs such as Esoterix and US Pathology Labs. 
 
Part of the growth in the new single analyte and multiplexed molecular and protein  tests is related to the perception that these tests offer physicians decision making  information not available with conventional tests.  As such they command premium  pricing. Therefore Quest and LabCorp have acquired several of the major esoteric testing  companies to enhance their position in this high-growth segment. 
 
These labs and other specialised reference labs have a clear advantage over test services offered by companies in their CLIA-registered labs.  They have established  distribution networks and immediate access to medical specialists.  Thus the esoteric test  segment is a clear winner for them.  The average cost of a molecular test performed in a  reference lab ranges from $10 to $50, reimbursement is usually at least $100 and the labs  often charge as much as $500 for these tests.
 
Promotional and clinical study activities that provide scientific and economic evidence  of the value of high-priced esoteric tests do not come cheap.  None of the test companies  that have launched in-company test services are in the black.  Genomic Health’s success  has been hard bought.  The company has invested in researching a panel of biomarkers that has proved effective and has supported numerous clinical studies.  Where Genomic  Health and other companies that market test services save is in lab technologist training  costs, after sales service and continuing education.


The reagent and instrumentation costs for many multiplexed esoteric and genomic tests are still high and demand is relatively low, most hospital labs would not be able to justify investment in offering these tests.  Thus, it may appear that profit consideration is  the driving force for test services.  In effect, the most obvious route to market for complex and still esoteric tests is via collaboration with a reference lab or a CLIA-registered company lab.  In this way the test becomes available to the largest number of  physicians and patients. [3]
"Reference labs are usually private, commercial facilities that do high volume routine and specialty testing. Most of the tests performed are referred from physician’s offices, hospitals and other health care facilities (e.g., nursing homes and other facilities). While most hospitals try to do as many tests as possible in-house, reference labs are used for specialized tests that are ordered only occasionally or that require specialized equipment." [2]


"The major national reference labs including Quest, LabCorp, Specialty/Ameripath, Mayo and others account for at least 60% of the market for esoteric test services. The remaining 40% is shared by a group of some 3000 small, local market laboratories. The major reference labs have built a comprehensive menu of specialized test services and continue to expand their offerings via collaborations with leading medical research centers. They offer a huge presence in the market and manage distribution networks that touch just about every medical specialty. Thus many CLIA-registered company sponsored test services avail themselves of the marketing resources offered by the national reference labs." [3]


* [1] http://www.labtestsonline.org/lab/labtypes-3.html
* [1] Goodman et al. The Value of Diagnostics: Innovation, Adoption and Diffusion Into Health Care. (2005) pp. 28
* [2] Rosen. Diagnostic Test Service Commercialization: A Roadmap to Diagnostics in the 21st Century.  (2008) pg. 22
* [2] http://www.labtestsonline.org/lab/labtypes-3.html
* [3] ''Ibid.'' pp. 47-48
* [3] Rosen. Diagnostic Test Service Commercialization: A Roadmap to Diagnostics in the 21st Century.  (2008) pg. 22
* [4] Goodman et al. The Value of Diagnostics: Innovation, Adoption and Diffusion Into Health Care. (2005) pp. 28


== PreMarket Approval (PMA) ==
== Pharmacogenetics & Pharmacogenomics (PGx) ==
"Premarket approval (PMA) is the FDA process of scientific and regulatory review to evaluate the safety and effectiveness of Class III medical devices. '''Class III devices are those that support or sustain human life, are of substantial importance in preventing impairment of human health, or which present a potential, unreasonable risk of illness or injury.''' Due to the level of risk associated with Class III devices, FDA has determined that general and special controls alone are insufficient to assure the safety and effectiveness of class III devices. Therefore, these devices require a premarket approval (PMA) application under section 515 of the FD&C Act in order to obtain marketing clearance. Please note that some Class III preamendment devices may require a Class III 510(k). See "Historical Background" for additional information.
Pharmacogenetics and/or pharmacogenomics (PGx) is the study of differential drug response due to genetic variation.  The two terms tend to be used interchangeably, although the -genetics suffix suggests studies and assertions involving tens of genes while -genomics suggests hundreds or thousands. Many clinical applications to date have focused on drug-metabolizing enzymes such as [http://en.wikipedia.org/wiki/Cytochrome_P450#CYP_families_in_humans CYP450]s.  Other tests examine tens of genes to predict the most efficacious anti-cancer drug. In general, PGx studies attempt to rationally optimize drug choice and dosage while minimizing side-effects.


PMA is the most stringent type of device marketing application required by FDA. The applicant must receive FDA approval of its PMA application prior to marketing the device. PMA approval is based on a determination by FDA that the PMA contains sufficient valid scientific evidence to assure that the device is safe and effective for its intended use(s). An approved PMA is, in effect, a private license granting the applicant (or owner) permission to market the device. '''The PMA owner, however, can authorize use of its data by another.'''" [1]
Drug developers are increasingly including PGx studies in clinical trials and subsequently marketing both PGx diagnostics and the drug or drugs indicated by the test. Note that the included diagnostic does not necessarily help diagnose the condition, but instead determine the appropriate therapeutic response.


[1] http://www.fda.gov/medicaldevices/deviceregulationandguidance/howtomarketyourdevice/premarketsubmissions/premarketapprovalpma/default.htm
See the recent paper by [[Diagnostic_Kits/Clinically Available Pharmacogenomics Tests|Flockhart et al]] for a review of 11 pharmacogenomic diagnostics currently on the market.


== PreMarket Notification 510(K) ==
==Pre-market Approval (PMA)==
The 510(k) process requires manufacturers of medical devices to notify the [FDA], at least 90 days in advance, of their intent to market a product in the US. The Agency then determines if the product is exempt (subject only to the general controls of the statute), is as safe and as effective as a legally marketed device of the same generic type or that the device requires premarket approval.  A new device found to be not substantially equivalent (“NSE”) is classified as class III and a substantially equivalent new device is classified in the same regulatory class, either class II or class I, as the device to which it is found equivalent. Therefore, the 510(k) process serves as a means to classify new devices. [1]
''See [[Diagnostic_Kits/USA_Regulation_Review#Pre-Market_Approvals_.28PMAs.29|FDA Pre-Market Approvals]]''


So all medical devices must pass through the 510(K) process on their path to the market, and the riskiest devices must also receive [[Diagnostic_Kits/Glossary#PreMarket_Approval_.28PMA.29|premarket approval]], which is a much more elaborate process involving clinical trials.
==510(k) Pre-Market Notifications==
''See [[Diagnostic_Kits/USA_Regulation_Review#510.28k.29_Pre-Market_Notification_.28PMN.29|FDA 510(k) Pre-Market Notifications]]''


* [1] AdvaMed (2008), ''The 510(k) Process: The Key to Effective Device Regulation''. pp. 8-9
==Navigation==
Back to [[Diagnostic Kits]]<br/>
[[Category:Diagnostic Kits]]

Latest revision as of 09:57, 29 June 2010

Abbreviations

The table below is a list of commonly used abbreviations throughout this wiki.

Abbreviations
Abbreviation Definition
510(k)/PMA Pre-Market Notification
ASR Analyte Specific Reagent
CLIA Clinical Laboratory Improvement Amendments Act
CMS Centers for Medicaid and Medicare Services
FDA Food and Drug Administration
IVDs ''In Vitro'' Diagnostics
IVDMIAs ''In Vitro'' Diagnostic Multi-Variate Assays
LDTs Laboratory Developed Tests

Analyte Specific Reagent (ASR)

Generally, the term “analyte specific reagent” or “ASR” is used to describe a component of a genetic test that is commonly sold or used with a “testing kit.” Scientists use the term to describe certain types of biochemical, chemical, or other substances, and occasionally devices, that are used to conduct a test at a laboratory. However, because the FDA regulates the use and sale of ASRs to some extent, the definition used within the FDA regulations is also commonly used in practice.

Although ASRs are often defined in layman’s terms as the “building blocks” or “active ingredients” of a test, it's helpful to understand how genetic tests are brought to market. Genetic tests tend to be developed either as a "Testing Kit" which is commercially sold to laboratories who conduct the tests, or as a "Laboratory Developed Test" (or LDT), which is developed by a laboratory solely for "in-house use," and is not commercially sold to other entities.

Testing Kits: When a device manufacturer develops a genetic test and sells it to a laboratory who will collect the specimen and actually conduct the test, they sell the test as a "kit" that includes all the necessary ASRs, as well as instructions on how to conduct the test.
LDTs: when a testing laboratory develops its own genetic test, including the ASRs, and uses the test (also called a in-house, home brew, or LDT) only at their testing laboratory and does not commercially sell the test to anyone else.

The differences of how the test is developed and sold is important for regulatory reasons. Different federal regulations apply to the sale and use of ASRs. This depends on whether the ASR is being used soley for in-house use at a laboratory (i.e., LDTs), or if it is being sold commercially by testing manufacturers as part of a kit.

For regulatory purposes, the FDA defines ASRs as:

“antibodies, both polyclonal and monoclonal, specific receptor proteins, ligands, nucleic acid sequences, and similar reagents which, through specific binding or chemical reaction with substances in a specimen, are intended for use in a diagnostic application for identification and quantification of an individual chemical substance or ligand in biological specimens.”[1]

For more information on the regulatory distinctions of ASRs see our wiki page on U.S. Regulation.

See Also:

Clinical Laboratory Improvement Amendments (CLIA)

See CMS Regulations

Analytical & Clinical Validity & Utility

One problem that is repeatedly encountered in literature is how to quantify the proficiency and usefulness of a particular genetic test. At present, there are no universally established standards for genetic tests to determine proficiency and usefulness by a regulatory body. However, Professional Associations, Laboratory Accreditation Organizations, Policy Groups and Patient Advocacy Organizations all seem to agree that the follow criteria are important when addressing these questions.

Analytical Validity: refers to the level of accuracy and consistency with which a particular genetic characteristic, such as a DNA sequence variant, chromosomal deletion or biochemical indicator, can be identified in a given laboratory test.
Clinical Utility: defines the risks and benefits associated with the introduction of a test into practice, including the impact of positive and negative test results on health outcomes, cost-effectiveness, and ethical, legal and social issues associated with test use.
Clinical Validity: refers to the accuracy of a test when used to identify the presence of disease or predict a patient's clinical status.

See Also:

Genetics vs Genomics

Genetics

Genetics is a term that refers to the study of genes and their role in inheritance - the way certain traits or conditions are passed down from one generation to another. Genetics involves scientific studies of single genes and their effects. Genes (units of heredity) carry the instructions for making proteins, which direct the activities of cells and functions of the body. Genes influence traits such as hair and eye color as well as health and disease development. Genetics determines much (but not all) of a person's appearance and health status, but environmental differences also play a part. Examples of single gene disorders that would be considered as "genetics" include cystic fibrosis and PKU (phenylketonuria).

See Also:

Genomics

Genomics is a relatively new term that describes the study of all of a person's genes including interactions of those genes with each other and the person's environment. Genomics involves the scientific study of complex diseases such as heart disease, asthma, diabetes and cancer because they are caused more by a combination of genetic and environmental factors. Genomics is offering new possibilities for therapies and treatment of some diseases, as well as new diagnostic methods. The major tools and methods related to genomics studies are bioinformatics, genetic analysis, measurement of gene expression, and determination of gene function.

See Also:

Typology of Genetic Tests

See Regulatory Classifications of Genetic Tests

In-Vitro Diagnostic Multivariate Index Assay (IVDMIAs)

See Regulatory Classifications of Genetic Tests

Direct Access Testing (DAT)

"As with home testing, direct access testing (DAT) has been growing in popularity over the past few years. Currently, 34 states permit consumers to order their own lab tests - without a medical order from their health care provider. Also known as patient authorized testing, DAT is a reflection of Americans' focus on health and preventive medicine, offering the opportunity for patients to take a more active role in their own health care.

In some respects, direct access testing has been around for some time. Over-the-counter home tests are a type of DAT since they do not require a prescription and can be bought and used at the consumer’s discretion. Now, the trend has expanded to include laboratories offering clinical tests at the patient’s request. In retail centers in Colorado, Montana, Missouri, Kansas, and Utah, patients can walk into a lab and request certain tests; wellness centers offer health screens and other lab tests; and free-standing and mobile testing facilities offer screening tests to the public, such as in grocery stores and pharmacies.

Most DAT labs limit the availability of tests to simple, general health tests such as complete blood counts (CBC), cholesterol levels, throat and urine cultures, diabetes screening (blood glucose tests), chemistry panels, PSA for prostate cancer, thyroid tests, HIV antibody tests, blood typing, pregnancy tests, and urine drug screens.

Direct access testing may reduce costs for the patient by eliminating the expense of doctor’s office visits, providing vital information to patients who are concerned with a particular health problem or who may otherwise avoid testing due to inconvenience or concerns over anonymity. However, most insurance companies do not cover tests that are not ordered by a physician; therefore, you should expect to pay out-of-pocket for these services. In addition, labs providing DAT services must provide consumers with reference ranges and some assistance in interpreting the results. However, you are not operating under the guidance of your physician, who may be better able to determine what tests you really need but also what the results of those tests mean in light of your specific clinical signs, symptoms, and medical history." [1]


Direct to Consumer (DTC)

IVDs sold directly to consumers who operate the tests themselves. Also known as Over the counter (OTC) or home-based kits. Some DTC products may also be considered DAT products. In these cases, the consumer collects the sample themselves with a sampling kit and mails it away for analysis in a commercial lab (DNAdirect's products work this way). In most DTC IVDs, such as home pregnancy tests or blood glucose tests, the sample collection and analysis happens together in the home.

"While the majority of diagnostic tests are conducted by clinicians and laboratory personnel, individual consumers also purchase diagnostics for private use in their homes. The market for home testing devices expanded from $1.19 billion in 1994 to $4.8 billion in 2002. Among home testing devices approved by the FDA are those that measure cholesterol levels, glucose levels, vaginal pH levels, blood clotting time (for patients on blood thinning drugs such as warfarin) and the presence of fecal occult blood (for detecting colon cancer). The FDA also has approved home testing devices that test for hepatitis C virus (HCV) and HIV, as well as for detecting menopause, pregnancy and drug abuse. The most frequently used home testing devices include blood glucose monitors for diabetics, pregnancy tests and cholesterol tests." [1]

  • [1]Goodman et al. The Value of Diagnostics: Innovation, Adoption and Diffusion Into Health Care. (2005) pp. 58-59

Reference Lab

"When diagnostic capabilities are needed beyond those provided in hospitals and physician practices, analysis is conducted in reference labs. While reference labs comprise only 2.8% of all clinical labs within the US, these facilities are responsible for 32% of the diagnostic industry’s revenue, due to their focus on processing large volumes of diagnostic tests for a broad client base. Reference labs generally perform both routine testing and esoteric testing. The largest reference labs may conduct more than 4,400 different types of tests, ranging from high-throughput routine tests (e.g., routine culture, cholesterol tests, Pap smears) to complex or specialized diagnostic tests for Lyme’s disease, cancer, cardiovascular disease and HIV." [1]

"Reference labs are usually private, commercial facilities that do high volume routine and specialty testing. Most of the tests performed are referred from physician’s offices, hospitals and other health care facilities (e.g., nursing homes and other facilities). While most hospitals try to do as many tests as possible in-house, reference labs are used for specialized tests that are ordered only occasionally or that require specialized equipment." [2]

"The major national reference labs including Quest, LabCorp, Specialty/Ameripath, Mayo and others account for at least 60% of the market for esoteric test services. The remaining 40% is shared by a group of some 3000 small, local market laboratories. The major reference labs have built a comprehensive menu of specialized test services and continue to expand their offerings via collaborations with leading medical research centers. They offer a huge presence in the market and manage distribution networks that touch just about every medical specialty. Thus many CLIA-registered company sponsored test services avail themselves of the marketing resources offered by the national reference labs." [3]

  • [1] Goodman et al. The Value of Diagnostics: Innovation, Adoption and Diffusion Into Health Care. (2005) pp. 28
  • [2] http://www.labtestsonline.org/lab/labtypes-3.html
  • [3] Rosen. Diagnostic Test Service Commercialization: A Roadmap to Diagnostics in the 21st Century. (2008) pg. 22

Pharmacogenetics & Pharmacogenomics (PGx)

Pharmacogenetics and/or pharmacogenomics (PGx) is the study of differential drug response due to genetic variation. The two terms tend to be used interchangeably, although the -genetics suffix suggests studies and assertions involving tens of genes while -genomics suggests hundreds or thousands. Many clinical applications to date have focused on drug-metabolizing enzymes such as CYP450s. Other tests examine tens of genes to predict the most efficacious anti-cancer drug. In general, PGx studies attempt to rationally optimize drug choice and dosage while minimizing side-effects.

Drug developers are increasingly including PGx studies in clinical trials and subsequently marketing both PGx diagnostics and the drug or drugs indicated by the test. Note that the included diagnostic does not necessarily help diagnose the condition, but instead determine the appropriate therapeutic response.

See the recent paper by Flockhart et al for a review of 11 pharmacogenomic diagnostics currently on the market.

Pre-market Approval (PMA)

See FDA Pre-Market Approvals

510(k) Pre-Market Notifications

See FDA 510(k) Pre-Market Notifications

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  1. FDA Regs., Definition of Analyte-Specific Reagents, 21 C.F.R. § 864.4020.