1 antiviral drug products advisory committee meeting nda 21-266voriconazole tablets nda...
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1
Antiviral Drug Products Advisory Committee Meeting
NDA 21-266 voriconazole tablets
NDA 21-267 voriconazole for injection
Rosemary Tiernan, MD, MPH
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Division of Special Pathogen and Immunologic Drug Products
Voriconazole Review Team
Jouhayna Saliba, RPh Marc Cavaillé-Coll, MD, PhD Gene W. Holbert, PhD Norman R. Schmuff, PhDOwen G. McMaster, PhD Kenneth L. Hastings, PhDLinda L. Gosey, MS Shukal Bala, PhD Philip M.Colangelo, PharmD, PhD Funmi O. Ajayi, PhDJoette M. Meyer,PharmD Wiley A. Chambers, MDCheryl A. Dixon, PhD Karen M. Higgins, ScDM. Regina Alivisatos, MD Edward M. Cox, MD, MPH Rosemary Johann-Liang, MD Rigoberto A. Roca, MDJohn H. Powers III, MD Rosemary Tiernan, MD, MPH
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Indications Requested in the NDA
Treatment of invasive aspergillosisEmpiric antifungal therapy of febrile neutropenic
patientsTreatment of: -candida esophagitis
-serious candida infections-serious fungal infections due to Fusarium and Scedosporium spp.-serious fungal infections in patients refractory or intolerant to other therapy
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FDA Presentation
Treatment of Invasive Aspergillosis
Empiric Antifungal Therapy of Febrile Neutropenic Patients
Clinical Safety
Questions to the Advisory Committee
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Treatment of Invasive Aspergillosis
Study 307/602
Study 304 and
Historical Control Study 1003
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Treatment of Invasive Aspergillosis
• Study 307/602– Randomized, controlled, open-label, initial therapy– Blinded Data Review Committee– voriconazole vs. amphotericin B followed by “other
licensed antifungal therapy” (OLAT)
• Study 304– Uncontrolled study of primary and salvage cases– Expert Panel– Retrospectively designed historical control
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Study 307/602• MITT
– voriconazole (N = 144)– amphotericin B (N = 133)
• Patient Characteristics– White male, hematologic malignancies, pulmonary
site
• Switch to OLAT– voriconazole 36.1% – amphotericin B 80.5%
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Study 307/602Primary Efficacy Endpoint
• Satisfactory Response at Week 12 (MITT)– voriconazole 76/144 52.8%– ampho B 42/133 31.6%
• 95% CI stratified by protocol (9.6, 33.6)
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Study 307/602Additional Efficacy Analyses
• Not allowing DRC to upgrade investigator assessment– vori 46.5% vs. ampho B 29.3%
• “Modified Week 12”– vori 45.1% vs. ampho B 31.6%
• Week 16 follow-up– vori 45.8% vs ampho B 33.1%
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Study 307/602Survival
AMPHOTERICIN B
VORICONAZOLE
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
0 10 20 30 40 50 60 70 80 90
SURVDAY
Probability of Survival at Day 84
vori 0.708 ampho B 0.579
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Study 304• Expert Evaluable Population
– Overall N = 112• Primary therapy N = 58• Salvage therapy N = 54
• Patient Characteristics– White male, hematologic malignancies,
pulmonary site, European population
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Study 304
• Expert Global Response at EOT (expert evaluable population)– Overall 55/112 49.1%
• Primary 35/58 60.3%• Salvage 20/54 37.0%
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Historical Control (HC)Study 1003
• Substantial effort to provide the most comparable population to primary therapy patients in Study 304– primary therapy was <5 days prior
antifungal therapy
• Matched on certainty of diagnosis, underlying disease, and site of infection
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Study 304/ Historical Control Study 1003
• Global Response– Study 304 vori 26/50 52.0%– Historical Control23/92 25.0%
• Probability of Survival at Day 90– Study 304 vori 0.554– Historical Control 0.417
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Historical Control Issues• Patient populations
– Study 304 only in Europe– Historical Control both in Europe and US– Global Response
– US HC 11/51 21.6%– EU HC 12/41 29.3%– Study 304 vori 26/50 52.0%
– Probability of Survival at Day 90 – US HC 0.290– EU HC 0.573– Study 304 vori 0.554
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Historical Control Issues (cont.)
• Duration of treatment– longer for voriconazole treated patients
• Difference in inclusion/exclusion criteria– which could possibly allow for sicker
patients in the HC
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Aspergillosis Summary
• HC good effort but still concerns about comparability of the study populations
• Study 304 results are used to support the randomized controlled study
• Study 307/602 showed– Non-inferior Global Response
• Statistically superior
– Survival Benefit
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Clinical Safety
Rosemary Tiernan, MD, MPH
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Clinical Safety
• Focus on 5 specific areas:– Ocular safety – Cardiac safety– Hepatic safety– Rash– Drug interactions
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Clinical Safety
• Focus on 5 specific areas:– Ocular safety– Cardiac safety– Hepatic safety– Rash – Drug interactions
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Ocular Safety
• Pre-clinical studies• Incidence in clinical studies is 1 out of every 3
subjects• Symptoms
Decreased vision, photophobia, altered color perception and ocular discomfort
• Unknown Mechanism• No human histopathology• Ocular biomicroscopy has not detected ocular
lesions
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Ocular safety
Results from study 150-1004– Effects noted in
• ERG• Farnsworth-Munsell 100 hue test (color vision)• Humphrey Perimetry (visual field)
– Drug effect on both rod and cone function– Decreased vision on day 1 and continued
through 28 days of therapy– Testing 2 weeks after the end of treatment
demonstrated return to normal function
23
Ocular Safety
Additional issues regarding use of this drug
-re-challenge or re-treatments
-ocular development in pediatric patients
-patients with underlying eye disease
-treatment beyond 28 days
24
Clinical Safety
• Focus on 5 specific areas:– Ocular safety– Cardiac safety– Hepatic safety– Rash– Drug interactions
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Cardiac Safety
• In vitro data
• In vivo data • Clinical data
– One sudden death
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Cardiac Safety
• Clinical data
– Adverse Events• Cardiac arrhthymias, CHF, cardiac arrests
– Discontinuations
27
Clinical Safety
• Focus on 5 specific areas:– Ocular safety– Cardiac safety– Hepatic safety– Rash– Drug interactions
28
Hepatic Safety Summary
• Phase I/II Studies– Positive dose (exposure) response with ALT and AST
• Phase III Comparative Studies– Hepatic adverse events and ALT & AST abnormalities
were more frequent with voriconazole than fluconazole
– Frequency of hepatic adverse effects similar between voriconazole and amphotericin B formulations studied
– Serious hepatic adverse events reported more frequently in voriconazole treated patients.
29
Clinical Safety
• Focus on 5 specific areas:– Ocular safety– Cardiac safety– Hepatic safety– Rash– Drug interactions
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Rash
• Difficulties in assessment of rash include:– Concomitant medications that can also
cause rash– Concomitant medications can affect the
type or severity of skin exanthem observed– Underlying conditions such as GVHD
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Rash Observed in 18.6% of patients on
voriconazole in therapeutic studies program
• Most rashes mild to moderate• No major differences in discontinuations for
rash• 4 non-fatal cases of Stevens-Johnson
32
Clinical Safety
• Focus on 5 specific areas:– Ocular safety– Cardiac safety– Hepatic safety– Rash – Drug interactions
33
Drug Interactions with VoriconazoleIn Vitro Metabolism
• Voriconazole is a substrate and inhibitor of CYP2C19, CYP2C9, CYP3A4
• Substrate affinity and inhibition potency of voriconazole is greater for CYP2C19 and CYP2C9 compared to CYP3A4
– CYP3A4 inhibition potency of voriconazole weaker than ketoconazole and itraconazole
• Potency of voriconazole to inhibit CYP3A4 metabolism varies among several CYP3A4 substrates (and vice-versa)
– HIV-PI, NNRTI, and Immunosuppressant Drugs
34
Drug Interactions with VoriconazoleIn Vivo Metabolism
• Representative substrates / inhibitors / inducers of the three CYP enzymes were studied, since it is not possible to evaluate every potential drug interaction – Example: HIV-PI and NNRTI drugs not studied in vivo
• CYP3A4 inhibitors and/or inducers• Exception: Indinavir no significant interaction
• The potential for drug interactions with voriconazole presents a therapeutic challenge for the prescriber
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Clinical Safety
Rosemary Tiernan, MD, MPH
36
Clinical Safety
• Focus on 5 specific areas:– Ocular safety – Cardiac safety– Hepatic safety– Rash– Drug interactions
37
Clinical Safety
• Focus on 5 specific areas:– Ocular safety– Cardiac safety– Hepatic safety– Rash – Drug interactions
38
Ocular Safety
• Pre-clinical studies• Incidence in clinical studies is 1 out of every 3
subjects• Symptoms
Decreased vision, photophobia, altered color perception and ocular discomfort
• Unknown Mechanism• No human histopathology• Ocular biomicroscopy has not detected ocular
lesions
39
Ocular safety
Results from study 150-1004– Effects noted in
• ERG• Farnsworth-Munsell 100 hue test (color vision)• Humphrey Perimetry (visual field)
– Drug effect on both rod and cone function– Decreased vision on day 1 and continued
through 28 days of therapy– Testing 2 weeks after the end of treatment
demonstrated return to normal function
40
Ocular Safety
Additional issues regarding use of this drug
-re-challenge or re-treatments
-ocular development in pediatric patients
-patients with underlying eye disease
-treatment beyond 28 days
41
Clinical Safety
• Focus on 5 specific areas:– Ocular safety– Cardiac safety– Hepatic safety– Rash– Drug interactions
42
Cardiac Safety
• In vitro data
• In vivo data • Clinical data
– One sudden death
43
Cardiac Safety
• Clinical data
– Adverse Events• Cardiac arrhthymias, CHF, cardiac arrests
– Discontinuations
44
Clinical Safety
• Focus on 5 specific areas:– Ocular safety– Cardiac safety– Hepatic safety– Rash– Drug interactions
45
Hepatic Safety Summary
• Phase I/II Studies– Positive dose (exposure) response with ALT and AST
• Phase III Comparative Studies– Hepatic adverse events and ALT & AST abnormalities
were more frequent with voriconazole than fluconazole
– Frequency of hepatic adverse effects similar between voriconazole and amphotericin B formulations studied
– Serious hepatic adverse events reported more frequently in voriconazole treated patients.
46
Clinical Safety
• Focus on 5 specific areas:– Ocular safety– Cardiac safety– Hepatic safety– Rash– Drug interactions
47
Rash
• Difficulties in assessment of rash include:– Concomitant medications that can also
cause rash– Concomitant medications can affect the
type or severity of skin exanthem observed– Underlying conditions such as GVHD
48
Rash Observed in 18.6% of patients on
voriconazole in therapeutic studies program
• Most rashes mild to moderate• No major differences in discontinuations for
rash• 4 non-fatal cases of Stevens-Johnson
49
Clinical Safety
• Focus on 5 specific areas:– Ocular safety– Cardiac safety– Hepatic safety– Rash – Drug interactions
50
Drug Interactions with VoriconazoleIn Vitro Metabolism
• Voriconazole is a substrate and inhibitor of CYP2C19, CYP2C9, CYP3A4
• Substrate affinity and inhibition potency of voriconazole is greater for CYP2C19 and CYP2C9 compared to CYP3A4
– CYP3A4 inhibition potency of voriconazole weaker than ketoconazole and itraconazole
• Potency of voriconazole to inhibit CYP3A4 metabolism varies among several CYP3A4 substrates (and vice-versa)
– HIV-PI, NNRTI, and Immunosuppressant Drugs
51
Drug Interactions with VoriconazoleIn Vivo Metabolism
• Representative substrates / inhibitors / inducers of the three CYP enzymes were studied, since it is not possible to evaluate every potential drug interaction – Example: HIV-PI and NNRTI drugs not studied in vivo
• CYP3A4 inhibitors and/or inducers• Exception: Indinavir no significant interaction
• The potential for drug interactions with voriconazole presents a therapeutic challenge for the prescriber