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Policy Challenges in Personal Genomics Kathy Hudson Genetics & Public Policy Center Johns Hopkins University www.DNApolicy.org. Acknowledgement-Disclosure NHGRI The Pew Charitable Trusts Eli Lilly Corporation . Personal Genomics. Challenges Evidence, evidence, evidence
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Policy Challenges in Personal Genomics Kathy Hudson Genetics & Public Policy Center Johns Hopkins University www.DNApolicy.org
Acknowledgement-Disclosure • NHGRI • The Pew Charitable Trusts • Eli Lilly Corporation
Personal Genomics • Challenges • Evidence, evidence, evidence • Analytic validity • Clinical validity • Clinical utility • Cost-effectiveness analysis • Who wants this information, how will it be used
Personal Genomics • Personalized medicine is only as good as the test used to inform drug selection and dose. • The current regulatory system is ill-equipped to meet this challenge. The right diagnostic is key to determining the right drug and the right dose.
Steps to Safe and Effective Genetic Testing • Test oversight should be based on risk and not mode of manufacture. • High risk tests should be subject to independent review before entering market. • Genetic tests should give the right answer nearly all the time. • Transparency: Data linking genotype to phenotype should be publicly accessible. • Pharmacogeneticdata should rapidly be incorporated into the label. • Demand truth in advertising, take action against false claims. • Quickly and rationally implement GINA.
Two Types of Tests • Laboratory developed tests (so-called homebrews) • Test “kits” • Level of regulatory oversight oddly disparate • Difference not apparent to patients and health care providers.
Labs using LDTs or FDA reviewed kits Test kits
Problems with “Two Path” System • Different standards based on mode of delivery (LDT v. Kit) • Absence of public access to information • Economic disincentive to FDA route • Difference in level of validation opaque to physicians and patient • Inadequate oversight of claims • Disincentive to develop point-of-care tests with global significance
CMS Regulation of Genetic Testing Laboratories • No requirement for proficiency testing (no external assessment of analytic validity) • No evaluation of clinical validity • Little public access to information • No authority over claims and labels • Buried in an agency with a different mission and expertise
FDA Regulation of Tests • Test kits • Evidence of clinical validity for intended use(s) included in submission • Authority over manufacturer or distributor claims • Only a few human genetic tests have been approved by FDA as kits • Laboratory-developed tests • Enforcement discretion • IVDMIA confusion • Ovasure oddity
Steps to Safe and Effective Pharmacogenetic Testing • Test oversight should be based on risk and • not mode of manufacture. • High risk tests should be subject to independent review before entering market. • Genetic tests should give the right answer • nearly all the time. • 4. Transparency: Data linking genotype to phenotype should be publicly accessible. • 5 . Pharmacogenetic data should be rapidly • incorporated into the label. • Demand truth in advertising, take action • against false claims • 7. Quickly and rationally implement GINA Image: www.candysnob.com
Variables in PGx Drug Re-labeling • Indication Efficacy vs. Toxicity vs. Dosage • Analyte Human vs. Microbial • Language Required vs. Recommended vs. Info • Timing Pre-market vs. post-market on or off patent • Diagnostic FDA cleared IVD or CLIA only • Alternatives Other drugs available for indication
Tale of two drugs, two adverse reactions, and two HLA-B alleles
Abacavir (Ziagen®) • Glaxo-Smith Kline • Inhibits the activity of HIV-1 reverse transcriptase • Hypersensitivity to abacavir is characterized by: • Fever • Rash • Gastrointestinal (including nausea, vomiting, diarrhea, or abdominal pain) • Constitutional (including generalized malaise, fatigue, or achiness) • Respiratory (including dyspnea, cough, or pharyngitis).
Genetic Variant Associated with Adverse Events (Abacavir) Hypersensitivity to abacavir was reported in approximately 8% of 2,670 patients (n = 206) in 9 clinical trials (range: 2% to 9%) with enrollment from November 1999 to February 2002. Patients who carry the HLA-B*5701 allele are at high risk for experiencing a hypersensitivity reaction to abacavir.
PREDICT-1 Clinical Trial • April 2006-April 2007 (n = 1,650) • randomized, double-blind study • Evaluated prospective HLA-B*5701 screening on the incidence of abacavir hypersensitivity reaction • Use of pre-therapy screening for the HLA-B*5701 allele and exclusion of subjects with this allele reduced the incidence of clinically suspected abacavir hypersensitivity reactions • 61% of patients with the HLA-B*5701 allele will develop a clinically suspected hypersensitivity reaction during the course of abacavir treatment compared with 4% of patients who do not have the HLA-B*5701 allele.
Black Box Warning Abacavir Label July 2008 No specific test named and LDTs are available. WARNING: HYPERSENSITIVITY REACTIONS/LACTIC ACIDOSIS AND SEVERE HEPATOMEGALY • Serious and sometimes fatal hypersensitivity reactions have been associated with ZIAGEN (abacavir sulfate). (5.1) • Hypersensitivity to abacavir is a multi-organ clinical syndrome. (5.1) • Patients who carry the HLA-B*5701 allele are at high risk for experiencing a hypersensitivity reaction to abacavir. (5.1) • Discontinue ZIAGEN as soon as a hypersensitivity reaction is suspected. Regardless of HLA-B*5701 status, permanently discontinue ZIAGEN if hypersensitivity cannot be ruled out, even when other diagnoses are possible. (5.1) • Following a hypersensitivity reaction to abacavir, NEVER restart ZIAGEN or any other abacavir-containing product. (5.1) • Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogues. (5.2)
Carbamazepine (Tegretol®) Novartis Sodium channel blocker Anti-convulsion and mood stabilizing drug used primarily in the treatment of epilepsy and bipolar disorder. It is also used to treat ADD, ADHD, schizophrenia, Phantom limb syndrome, Paroxysmal extreme pain disorder, and trigeminal neuralgia
Genetic Variant Associated with Adverse Events - Carbamazepine Retrospective case-control studies found association between HLA-B*1502 variant and risk of developing Steven Johnson Syndrome and Toxic epidermal necrolysis with carbamazepine treatment. Prevalence of HLA-B*1502 higher in people from China, Taiwan, Thailand, Malaysia, Indonesia, and the Philippines.
FDA moves at the speed of light 2004 Medical genetics: a marker for Stevens-Johnson syndrome.Chung WH, Hung SI, Hong HS, Hsih MS, Yang LC, Ho HC, Wu JY, Chen YT. Nature. 2004 Apr 1;428(6982):486. 2007 Investigation into the multidimensional genetic basis of drug-induced Stevens-Johnson syndrome and toxic epidermal necrolysis. Pirmohamed M, Arbuckle JB, Bowman CE, Brunner M, Burns DK, Delrieu O, Dix LP, Twomey JA, Stern RS. Pharmacogenomics. 2007 Dec;8(12):1661-91. Dec 19, 2007, FDA requested change to package insert March 1, 2008, FDA issues updated label
Black Box Warning: SERIOUS DERMATOLOGIC REACTIONS AND HLA-B*1502 ALLELE Serious and sometimes fatal dermatologic reactions, including toxic epidermal necrolysis (TEN) and Stevens-Johnson Syndrome (SJS), have been reported …. These reactions are estimated to occur in 1 to 6 per 10,000 new users in countries with mainly Caucasian populations, But, the risk in some Asian countries is estimated to be about 10 times higher. Studies in patients of Chinese ancestry have found a strong association between the risk of developing SJS/TEN and the presence of HLA-B*1502 and inherited allelic variant of the HLA-B gene. HLA-B*1502 is found almost exclusively in patients with ancestry across broad areas of Asia. PATIENTS WITH ANCESTRY IN GENETICALLY AT RISK POPULATIONS SHOULD BE SCREENED FOR THE PRESENCE OF HLA-B*1502 PRIOR TO INITIATING TREATMENT WITH TEGRETOL.
Epilepsy Drugs Currently Approved and Marketed Luminal Lyrica Mysoline® Neurontin® Oxcarbazepine Phenobarbital Phenytek® Phenytoin Primidone Rufinamide Sabril • Felbamate • Frisium • Gabapentin • Gabitril® • Inovelon® • Keppra® • KeppraXR™ • Klonopin • Lamictal® • Lamotrigine • Levetiracetam • Tegretol® • TegretolXR® • Tiagabine • Topamax® • Topiramate • Trileptal® • Valproic Acid • Vimpat • Zarontin® • Zonegran® • Zonisamide • Carbamazepine • Carbatrol® • Clobazam • Clonazepam • Depakene® • Depakote® • Depakote ER® • Diastat • Dilantin® • Ethosuximide • Felbatol®
Abacavir and Carbamazepine Timelines Abacavir Carbamazepine 1974 – approved Apr 2004 – genotype id’d No prospective trial Dec 2007 – retrospective published Mar 2008 – black box warning • Dec 1998 – approved • Mar 2002 – genotype id’d • Aug 2006 – trial begins • Aug 2007 – trial results • Feb 2008 – trial published • Jul 2008 – black box warning ~78 months ~50 months
FDA fickleness • Retrospective studies sufficient sometimes • RCTs required sometimes • Black box warnings are not warm and fuzzy • If alternative is available, physicians may not be willing to test to treat • Pharmaceutical companies seeking ‘genotype neutral’ drugs?
Steps to Safe and Effective Genetic Testing • Test oversight should be based on risk and not mode of manufacture. • High risk tests should be subject to independent review before entering market. • Genetic tests should give the right answer nearly all the time. • Transparency: Data linking genotype to phenotype should be publicly accessible. • Pharmacogeneticdata should rapidly be incorporated into the label. • Demand truth in advertising, take action against false claims. • Quickly and rationally implement GINA.