`.
`,1 "tow,
`'
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`5
`
`FDA CENTER FOR DRUG EVALUATION AND RESEARCH
`
`DIVISION or ANESTHETIC, CRITICAL CARE. AND ADDICTION DRUG Pnooucrs
`
`RFD-170, Room 93-451 5600 Fishers Lane. Rockville MD 2Q8_S7_
`
`Tel:(301)443-374l
`
`
`
`NDA 21-038, Dexmedetomidine ,HCl, was submitted by Abbott Laboratories Inc. on
`December
`18, 1998.
`Dexmedetomidine is a potent and highly selective a-Z-
`adrenoreceptor agonist.
`The sponsor claims that
`their product produces titratable,
`predictable sedation in an ICU setting, from which patients are easily arousable and
`cooperative. The sponsor also claims that their product provides improved analgesia in
`the postoperative ICU setting.
`The a-Z-adrenoreceptor agonist detomidine was
`developed for’u'se as a sedative/analgesic in horses and cattle and was registered for
`marketing in Finlandin 1983. Medetomidine, launched in 1987 in Scandinavia, was a
`more selective a¥2-adrenoreceptor agonist used as a sedative/analgesic in cats and dogs.
`It was approved for veterinary use in the US in 1997. The sedative and analgesic activity
`of medtomidine
`are believed to reside predominantly in
`its dextroenantiomer
`dexmedetomidine. The enantiomer was first synthesized by Farmos Group in Finland in
`1986. Numerous perioperative indications have been evaluated since that time. Farmos
`merged with Orion Corp.
`in 1990, and Orion licensed the injectable dosage form of
`dexmedetomidine for clinical use to Abbott Laboratories in 1994.
`
`MEMORANDUM
`
`November 5, 1999
`
`File, NDA 21-038
`
`Bob A. Rappaport, MD.
`Deputy Director, DACCADP
`Team Leader, Anesthetic Drug Group
`
`Supervisory Review of NDA 21-038, Dexmedetomidine HCl
`
`BACKGROUND:
`
`Orion conducted 56 clinical
`trials of dexinedetomidine with various modes of
`administration including rapid intravenous infusion. continuous intravenous infusion,
`
`Petition for Inter Partes Review of US 8,242,158
`Amneal Pharmaceuticals LLC — Exhibit 1019 — Page 1
`
`
`
`
`
`intramuscular injection, as well as transderrnal and oral administration. Abbott initiated
`its own clinical development program and completed 21 studies (13 Phase I and 8 Phase
`II/III) in the US, Canada and Europe. They also completed 2 studies in Japan: a Phase I
`safety and phannacokinetic study of rapid infusion in 9 healthy males, and a Phase II
`safety and dose response study of rapid infusion in 109 patients. The sponsor reported
`that the case report forms for these 2 studies were unavailable and they did not include
`the data in the [88 database.
`- _
`
`The clinical studies of the effectiveness and safety of this new formulation have been
`reviewed [submitted August 29, 1999] by Charles Cortinovis, MD. Dr. Patricia Hartwell
`contributed two addenda [submitted September 13, 1999 and October 27, 1999]
`reviewing safety data in the original application, a supplementary safety package, and the
`lZO-Day Safety Update. The application has also been reviewed by Jonathan Ma, Ph.D.
`(biostatistics), Suresh Doddapaneni, Ph.D. (clinical pharmacology and biopharmaceutics),
`Harry Geyer, Ph.D. (pharmacology/toxicology), Michael Theodorakis, Ph.D. (chemistry),
`and BeLinda A. Hayes, Ph.D. (abuse liability).
`In this memo, I will briefly review the
`effectiveness and safety data summarized in the primary clinical review, as well as any
`relevant information found in the primary reviews from the other disciplines, and make
`appropriate recommendations for action on the NDA.
`
`
`
`'
`
`EFFECTIVENE§S2
`
`Evidence of efficacy has been submitted in two clinical studies W97-245 and W97-246.
`
`Study W97-245'=
`
`This was a randomized, double blind, placeboocontrolled, parallel group study conducted
`at 33 centers in Canada and Europe. The Study consisted of two parts. Part 1 was an
`open-label evaluation of dexmedetomidine in up to 4 patients per site. This portion of the
`study was designed to allow the investigators to become familiar with the observed
`clinical effects of dexmedetomidine prior to starting the double-blind portion of the study.
`Patient data from Part I was not included in the efficacy analyses.
`'
`1'; 3.»-
`
`In Part II of the study, adult postoperative patients who required a minimum of 6 hours of
`ventilation and sedation in the ICU setting were randomized to either dexmedetomidine
`or placebo for sedation. Within one hour of admission to the 'ICU, patients were
`
`Dexmedetornidine
`NBA 2 l-038
`
`Petition for Inter Partes Review of US 8,242,158
`Amneal Pharmaceuticals LLC — Exhibit 1019 — Page 2
`
`
`
`administered a loading dose 6.0 ug/kg/hour over a 10 minute period, followed by a
`maintenance infusion of 0.4 ug/kg/hour.
`The infusion rate could be adjusted by
`increments of 0.1 ug/kg/hour in order to maintain a Ramsay Sedation Score1 of 3 or
`higher. However, it was required that the rate be maintained between 0.2 and 0.7
`ug/kg/hour. Following extubation, the infusion rate was adjusted to achieve a Ramsay
`Sedation Score of 2 or above. Study drug infusion was continued for at least 6 hours after
`extubation and, at the discretion of the investigator, up~to a maximum of 24 hours total
`study drug infusion.
`
`'
`
`Rescue medications were limited to midazolam for sedation and morphine for pain. After
`e‘xtubation, paracetamol was administered when clinically indicated. When the
`investigators judged that there was need for an increase in sedative medication, they were
`to first adjust the maintenance dose of dexmedetomidine. , .Midazolam was-administered
`as bolus doses of 0.02 mg/kg. Using the Ramsay Sedation Score,
`the patient was
`assessed prior to and 10 minutes after every rate change in study drug or administration
`of midazolam.
`if the patient required 3 bolus doses of midazolam within any 2 hour
`period, after appropriate adjustments of the study drug infusion rate, further midazolam
`was administered as a continuous infusion at 0.01 to 0.02 mg/kg/hour.
`
`
`
`The need for analgesic administration was assessed either by direct communication with
`the patient regarding pain, or by the presence of abnormal autonomic signs such as
`sweating, tachycardia and hypertension. Morphine was administered for pain as 2-mg
`intravenous boluses.
`
`The protocol Specified primary efficacy parameter was the total dose of midazolam in
`milligrams administered during the period that the patient was intubated. The efficacy
`analysis was based on the Intent to Treat [111'] population and analysis on the Evaluable
`population was also performed. A second primary efficacy endpoint was analde based
`on a recommendation made by the Division biostatistician, Dr. Permutt, at a development
`meeting with the sponsor. This endpoint was a comparison of the numbers of patients
`who fell into one of the following three categories of midazolam use:
`
`1. No dose
`2. Subthérapeutic dose
`3. Therapeutic dose
`0
`_
`.4
`
`(0 mg)
`(0-4 mg)
`(>4 mg)
`
`This outcome measure was not specified in any amendment to the protocol. However,
`the-analysis wa undertaken prior to breaking the study blind.
`'
`
`‘ 6 = asleep, no response
`5 = asleep. sluggish response to light glabellar tap or loud auditory stimulus
`4 = asleep but with brisk response to light glabellar tap or loud auditory stimulus
`3 = patient responds to commands
`'
`2 = patient cooperative, oriented. and tranquil
`! = patient anxious.'agitated. or restless
`':
`
`.
`Dexmedetornidine
`NDA 21-038
`
`Petition for Inter Partes Review of US 8,242,158
`Amneal Pharmaceuticals LLC — Exhibit 1019 — Page 3
`
`
`
`Secondary efficacy parameters listed in the protocol for this study included‘:
`
`.. I.
`
`2.
`
`Use of morphine for pain - as assessed by total dose used with
`dexmedetomidine as compared to placebo (mg/hr)
`Use of paracetamol for pain after extubation — as assessed by total dose used
`with dexmedetomidine compared to placebo (mg/hr)
`Time to extubation —- measured as time..of arrival
`extubation
`
`in ICU until
`
`time of
`
`Total dose of midazolam during study drug administration
`Total dose of morphine during study drug administration
`Total dose of morphine by time period
`- —
`'Ramsay Sedation Score
`_
`Ratio3 of Ramsay Sedation Score of “1” during study drug administration
`Time to extubation and weaning duration
`Nurses’ and patients’ assessment
`
`
`
`However, the secondary efficacy parameters listed in the study report were:
`
`.
`
`These changes in secondary outcome measures were not specified in any amendment to
`the protocol.
`
`Results:
`
`Eighty-six patients were enrolled and 85 treated in Part I of the study.
`
`In Part II of the study, 178 patients were randomized to dexmedetornidine and 175 to
`placebo. All patients were administered study drug and comprised the ITT population.
`Two dexrnedetomidine treated and 6 placebo patients were excluded from the Evaluable
`patient set.
`
`Dr. Coninovis’ Table 4
`patient disposition:
`-'; 25.
`
`[page 22 of his review], reproduced belOw, summarizes the
`
`i This information differs from that documented by Dr. Cortinovis in the medical officer's review and by
`Dr. Ma in the Statistician‘s review.
`It is based on documentation provided by Dr. Patricia Hartwell who
`examined the original documents at my request.
`’ The ratio is the proportion of assessments that equal 1 divided by the total number of assessments for the
`patient.
`-
`-‘
`I
`:- -
`Dexmedetomidine
`NDA 2l-038
`
`Petition for Inter Partes Review of US 8,242,158
`Amneal Pharmaceuticals LLC — Exhibit 1019 — Page 4
`
`
`
`Dexmedetomidine patients required statistically significantly less midazolam
`compared to the placebo treated patients in both the ITT and Evaluable patient
`analyses. Dr. Cortinovis’ Table 8, page 25 of his review, summarizes these results
`and is reproduced below:
`'
`'
`
`
`
`APPEARS nus WA?
`0» ORIGINAL
`
`Dexmedetomidine
`NDA 21-038
`
`Petition for Inter Partes Review of US 8,242,158
`Amneal Pharmaceuticals LLc — Exhibit 1019 — Page 5
`
`Table l.
`
`— Placebo
`175
`
`_ —
`
`noomm
`noon-mos
`1303,6004. _7601
`
`Received disallowed medication
`
`‘ Patients. could have had more than one reason for non-evaluability
`Modified Sponsor's Table 8.1a Vol. 8/ 10-62-73
`
`Nine patients in the dcxmcdetomidine group and 10 in the placebo group were
`discontinued fran the study prematurely. Each of these patieiits discontinued due to
`adverse events.
`
`Primary Eflicacy Analyses:
`
`l.
`
`
`
`Statistically significant differences were observed between the treatment groups in
`both the HT and Evaluable analyses, with the majority of the dexmedetomidine
`treated patients requiring no midazolam compared to'ilie majority of placebo
`patients who required greater than 4 mg of midazolam. Dr. Cortinovis‘ Table 9,.
`page 25 of his review, summarizes these results and is reproduced below:
`
`
`
`‘ p-value from ANOVA‘
`SEM = Standard Error of Mean
`
`Modified Sponsor’s Table 8.23 Vol. 8/10-62-74
`
`Table 3.
`
`Total Dose Categories of Midazolam During Intubation
`Placebo
`Dexmedetomidine
`
`Treatment
`Effect
`
`p-Value'
`
`_—
`
`——I
`
`rr—
`__
`
`—- ‘
`
`p-value from chi-square
`Modified Sponsor‘s Table 8.2b Vol. 8110-62-75
`
`Secondary Eflicacy Analyses:
`
`Their were mdifferences in any of the analyses when performed on either the ITT or
`Evaluable patient data sets. The following table, based on Dr. Ma’s Table 3.3, page 6 of
`his review,_summarizes the results for six of these analyses:
`
`Dexmedetomidine
`NDA 21-033
`
`Petition for Inter Partes Review of US 8,242,158
`Amneal Pharmaceuticals LLC — Exhibit 1019 — Page 6
`
`Table 2.
`
`Total Dose of Midazolam (mg) During Intubation
`
`_ “mmp-Value'
`
`_m
`
`n—
`- _—
`'
`18.4614.”
`45611.42
`0.0014
`
`Evaiuabnepauem (N)
`Mean t SEM
`
`
`
`Table 4.
`
`Placebo
`N =- 175
`Mean :9: SEM‘
`
`Dexmedctomidine
`N a 178
`Mean i SEM
`
`p-value
`Treatment Effect
`
`Total dose of midazolam during drug
`administration (mg/hour)
`
`Total dose of morphine during drug
`administration (mg/hour)
`
`1.19 (0.23)
`
`0.29 (0.07)
`
`0.83 (0.07)
`
`-
`
`0.47 (0.06)
`
`Total dose of morphine during 0 to 6.5
`. hours (mg)
`-
`r
`
`3.5 (0.79) -»
`
`4.9 (0:56)
`
`Total dose of morphine during 6.5 to
`end (mg/hour)
`
`Ramsay Sedation Score AUC during
`drug administration
`
`0.42 (0.08)
`
`0.24 (0.05)
`
`3.3 (0.05)
`
`3.6 (0.05)
`
`Ratio of Ramsay Sedation Score of 1
`during drug administration (Va)
`
`7 (0.8)
`
`3 (0.5)
`
`‘SEM = Standard Error of Mean
`
`
`
`As noted by Dr. Ma in his review, the Ramsay Sedation Score itself (AUC) was not a
`useful endpoint to consider as, for both groups, dose titration and rescue medication were
`used to maintain the patients at a specified level of sedation indicated by the Ramsay
`Score. However, a smaller ratio of Ramsay score of 1, for any particular patient, might
`indicate less anxiety during the treatment period. Statistically significant center effects
`were noted for most secondary endpoints indicating that patients in different countries
`either required and/or were administered differing amounts of sedative and analgesic
`medications.
`
`The following additional secondary endpoints were discussed by Dr. Cortinovis in his
`review:
`.-.-~ 2.5-.
`
`Time to extubation and weaning duration:
`‘
`L-
`
`No statistically'significant differences were noted in time to readiness for extubation or
`actual extubation, when that time was measured either from ICU arrival or start of study
`drug. No statistically significant differences were found between the treatment groups for
`median duration of weaning.
`
`Nurses’ and patients’ assessment
`
`Dexmedetomidine treated patients had a Statistically significantly lower patient
`management index [defined on page 30 of Dr. Cortinovis’ review] score compared with
`:- -
`Dexmedetomidine
`NDA 2l-O38
`
`Petition for Inter Partes Review of US 8,242,158
`Amneal Pharmaceuticals LLc — Exhibit 1019 — Page 7
`
`
`
`placebo treated patients. However, the actual numerical differences were noTlikely to be
`clinically relevant, according to Dr. Cortinovis.
`
`Patient satisfaction survey
`
`rated similarly their present
`The dexmedetomidine treated and placebo patients
`experience with sedation compared to prior experiences, their comfort during the ICU
`sedation, their remembrance of pain, discomfort from breathing tube, people and noise,
`and whether or not they would have the same sedative treatment in the future. However, .
`61% of dexrnedetomidine treated patients compared to 52% of placebo patients rated
`their overall experience as “better than expected?
`
`.
`
`Data Integrity;
`
`The. Division of Scientific Investigations’ [DSI] Clinical Inspection Summary for this
`application notes that one of the two pivotal study sites inspected by DSI was found to
`have protocol violations which may compromise some of the data arising out of that site.
`That site in Study W97-245 enrolled 5 out of 45 patients out of sequence; and one of
`those five subjects appeared to be a seven year old child who did not meet the inclusion
`criterion for age. DSI hasrequested clarification of the discrepancies and recommends
`that, until the matters are clarified and found to be satisfactory, we not use the data from
`those five subjects in support of the application.
`
`
`
`Dr. Thomas Permutt, biostatistics teamleader, has reviewed the data and the D81
`
`recommendations and has concluded that removal of the data from those five patients
`would not affect the outcome of the efficacy analyses.
`
`Studv W97-246:
`
`This was a randomized, double blind, placebo-controlled, parallel group study conducted
`at 36 centers in Canada and Europe. The Study consisted of two parts. Part I was an
`open-label evaluation of dexmedetomidine in up to 4 patients per site. This portion of the
`study was designed to allow the investigators to become familiar with the observed
`clinical effeCES‘of'dexmedetomidine prior to starting the double-blind portion of the study.
`Patient data from Part I was not included in the efficacy analyses.
`
`In Part II of the study, adult postoperative patients who required a minimum of 6 hours of
`ventilation and sedation in the ICU setting were randomized to either dexmedetomidine
`or placebo for sedation. Within one hour of admission to the ICU, patients were
`administered a loading dose 6.0 pg/kg/hour over a 10 minute period, followed by a
`
`Dexmedetomidine
`NDA 21-038
`
`‘ Petition for Inter Partes Review of US 8,242,158
`Amneal Pharmaceuticals LLC — Exhibit 1019 — Page 8
`
`
`
`The infusion rate could be adjusted by
`maintenance infusion of 0.4 pg/kg/‘hour.
`increments of 0.1 pg/kg/hour in order to maintain a Ramsay Sedation Score‘ of 3 or
`higher. However,
`it was required that the rate be maintained between 0.2 and 0.7
`ug/kg/hour. Following extubation, the infusion rate was adjusted to achieve a Ramsay
`Sedation Score of 2 or above. Study drug infusion was continued for at least 6 hours after
`exrubation and, at the discretion of the investigator, up to maximum of 24 hours total
`study drug infusion;
`_ .
`
`The need for analgesic administration was assessed either by direct communication with
`the patient regarding pain, or by the presence of abnormal autonomic signs such as
`sweating, tachycardia and hypertension. Morphine was administered for pain as 2-mg
`intravenous boluses.
`
`in
`The protocol specified primary efficacy parameter was the total dose of prepofol
`milligrams administered during the period that the patient was intubated. The efficacy
`analysis was based on the Intent to Treat [111‘] population and analysis on the Evaluable
`population was also performed. A second primary efficacy endpoint was analyzed based
`on a recommendation made by the Division biostatistician, Dr. Permutt, at a development
`meeting with the sponsor. This endpoint was a comparison of the numbers of patients
`who fell into One of the following three categories of propofol use:
`
`1. No dose
`
`2. Subtherapeutic dose
`3.:~£I'herapeutic dose
`
`This outcome measure was not specified in any amendment to the protocol. However,
`the analysis Was undertaken prior to breaking the study blind.
`
`Rescue medications were limited to propofol for sedation and morphine for pain. After
`extubation, paracetamol was administered when clinically indicated. When the ‘
`investigators judged'that there was need for an increase in sedative medication, they were
`to first adjust the maintenance dose of dexmedetomidine. Propofol was administered as
`bolus doses of 0.02 mg/kg. Using the Ramsay Sedation score, the patient was assessed
`prior to and 10 minutes after every rate change in study drug or administration of
`propofol.
`tf‘the patient required 3 bolus doses of propofol within any 2 hour period, after
`appropriate adj ustments of the study drug infusion rate, further propofol was administered
`as a continuous infusion at 0.5 to 4.0 mg/kg/hour.
`
`
`
`‘ 6 = asleep. no response
`5 = asleep. sluggish response to light glabellar tap or loud auditory stimulus
`4 = asleep but with brisk reSponse to light glabellar tap or loud auditory stimulus
`3 = patient responds to commands
`2 = patient cooperative. oriented, and tranquil
`l = patient anxiousfagitated, or restless
`5
`
`I
`Dexmedetomidine
`NBA 2 l-038
`
`Petition for Inter Partes Review of us 8,242,158
`Amneal Pharmaceuticals LLC — Exhibit 1019 — Page 9
`
`
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`
`Petition for Inter Partes Review of US 8,242,158
`Amneal Pharmaceuticals LLC – Exhibit 1019 – Page 10
`
`
`
`_
`
`7
`
`a
`
`Modified Sponsor's Table 8.1a Vol. 8/ 10-86-73
`
`Fourteen patients in the dexmedetomidine groupand 8 in the placebo group were
`discontinued from the study prematurely. Most of these patients discontinued due to
`adverse events...
`- -
`
`Primary Eflicacy Analyses:
`
`1. Dexmedetomidine patients,_required statistically significantly less propofol
`compared to the placebo treated patients in both the HT and Evaluable patient
`analyses. Dr. Cortinovis’ Table 22, page 47 of his review, summarizes these
`results and is reproduced, with modifications, below:
`
`
`
`APPEARS THIS WAY
`0N ORIGINAL
`
`Dexm edetomidine
`NDA 21-038
`
`Petition for Inter Partes Review of US 8,242,158
`Amneal Pharmaceuticals LLc — Exhibit 1019 — Page 11
`
`
`
`
`
`Table 6.
`
`Total Dose of Propofol (mg) During Intubation
`Placebo
`Dexmedetomidine
`
`Treatment Effect
`
`p-Value'
`m_z__
`
`__—
`
`‘ p-value from ANOVA
`SEM = Standard Error of Mean
`
`Modified Sponsor‘s Table 8.2a Vol. 8110-86-73
`
`.'
`
`- "
`
`2. Statistically significant differences were observed between the treatment groups
`in both the ITT and Evaluable analyses, with the majority of the
`'
`'
`dexmedetomidine treated patients requiring no propofol compared to the
`majority of placebo patients who required greater than 50 mg of propofol. Dr.
`Cortinovis’ Table 24, page 48 of his review, summarizes these results and is
`reproduced, with modifications, below:
`
`
`
`Table 7.
`
`Total Dose Categories of Propofol During Intubation
`Placebo
`Dexmedetomidine
`
`Treatment
`Effect
`
`pNalue‘
`__
`_—
`
`__I
`
`ii—za—
`uni——
`
`— m
`
`adam/9) _
`
`‘ p-value from chi-square
`Modified Sponsor‘s Table 8.2b Vol. 8/ [0-86-74
`
`Secondary Eflicacy Analyses:
`
`Their were no differences in any of the analyses when performed on either the ITT or
`Evaluable patient-data sets. The following table, based on Dr. Ma's Table 3.6, page 10 of
`his review, summarizes the results for six of these analyses:
`
`Dcxmedetoinidine
`NBA 2 l-O38
`
`Petition for Inter Partes Review of US 8,242,158
`Amneal Pharmaceuticals LLc — Exhibit 1019 — Page 12
`
`
`
`Total dose of midazolam during drug
`administration (mg/hour)
`
`Total dose of morphine during drug
`administration (mg/hour)
`
`Total dose of morphine during 0 to 6.5
`hours (mg)
`"
`
`Placebo
`N - 198
`Mean :t SEM“
`
`Dexmedetomidine
`N = 203
`Mean 1 SEM
`
`p-value
`Treatment Effect
`
`39 (4.1)
`
`5.3 (1.2)
`
`<0.000|
`
`0.89 (0.07)
`
`0.43 (0.05)
`
`<0.0001
`
`8.5 (0.64)"
`
`4.! (0.47)
`
`<0.000l
`
`Tetal dose of morphine during 6.5 to
`end (mg/hour)
`
`0.55 (0.07)
`
`_.
`0.l6 (0.03)
`
`<0.0001
`
`Ramsay Sedation Score AUC during
`drug administration
`
`Ratio of Ramsay Sedation Score of 1
`during drug administration (%)
`
`‘SEM = Standard Error of Mean
`
`3.] (0.04)
`
`3.4 (0.04)
`
`<0.000l
`
`7 (0.7)
`
`4 (0.5)
`
`0.0008
`
`
`
`
`
`As noted by Dr. Ma in his review, the Ramsay Sedation Score itself (AUC) was not a
`useful endpoint to consider as, for both groups, dose titration and rescue medication were
`used to maintain the patients at a specified level of sedation indicated by the Ramsay
`Score. However, a smaller ratio of Ramsay score of 1, for any particular patient, might
`indicate less anxiety during the treatment period. Statistically significant center effects
`were noted for most secondary endpoints indicating that patients in different countries
`either required and/or were administered differing amounts of sedative and analgesic
`medications.
`
`
`
`The following additional secondary endpoints were discussed by Dr. Cortinovis in his
`.v: :5-
`review:
`
`Time to extubation and weaning duration:
`
`No statistically significant differences were noted in time to readiness for extubation or
`actual extubation, when that time was measured either from ICU arrival or start of study
`drug. No statistically significant differences were found between the treatment groups for
`median duration of weaning.
`
`Nurses‘ and patients‘ assessment
`
`statistically significantly lower patient
`Dexmedetomidine treated patients had a
`management indéft‘ [defined on page 52 of Dr.;Cortinovis’ review] score compared With
`:- .
`Dexmedetomidine
`NDA 21-038
`
`Petition for Inter Partes Review of US 8,242,158
`Amneal Pharmaceuticals LLc — Exhibit 1019 — Page 13
`
`
`
`l4
`
`placebo treated patients. However, the actual numerical differences were not likely to be
`clinically relevant, according to Dr. Coninovis.
`
`Patient satisfaction survey
`
`The dexmedetomidine treated and placebo patients rated similarly their present
`experience with sedation compared to prior experiences, their comfort during the ICU
`. sedation, their remembrance of pain, discomfort from breathing-tube, people and noise,
`and whether or not they would have the same sedative treatment in the future. However,
`70% of dexmedetomidine treated patients compared to 60% of placebo patients rated '
`their overall experience as “better than expected?
`
`Subgroup Analyses of Emcag:
`
`7‘-
`
`Dr. 'Ma has reviewed the sponsor’s subgroup analyses and reports a few exceptions to the
`overall findings of significant efficacy of dexmedetomidine. These include:
`
`
`
`1.. Of the 43 patients in both groups at the five German centers in Study 245,
`only 1
`(5%) in the treated group required 0 mg of midazolam during the
`intubation period. At the other centers more than 50% of the treated patients
`required no midazolam.
`.
`. For the 20 patients at the single Austrian center in Studies 245 and 246,
`similar amounts of midazolam and propofol were required by the placebo and
`dexmedetomidine treated groups.
`. When analyzed by type of surgery, similar amounts of midazolam were
`required by the 34 patients undergoing head and neck surgery in. Study 245
`(p=0.96). Statistically significant differences were found for the two treatment
`groups for patients undergoing cardiac surgery,
`laparotomy and other
`surgeries in that study and all types of surgery in Study 246. However, the p-
`value for head and neck surgery for Study 246 was 0.052.
`
`
`
`SAFETY:
`
`-':-
`
`The origingquDA submission-excluded the W am from the 188
`database. This fact was discovered by Dr. Cortinovis after the submission had been filed.
`In a teleconference in late May of 1999, the sponsor claimed that they had not included
`this data because it came from studies performed to assess different indications than the
`one that is the subject of this application. The sponsor was informed that it would be
`necessary for them to compile, analyze and submit this missing data. The sponsor
`informed us that it would take a minimum of two months to complete the assignment and
`an early August submission was agreed upon. The new data was submitted on August
`16, 1999. This submission was fOund to be incomplete, with missing case report forms
`[CRF’s], CRF’s_'f_rom the .' ~
`- which had not been translated, and missing
`
`I7
`
`g .
`
`Dexmedetomidine
`NDA 21-038
`
`Petition for Inter Partes Review of US 8,242,158
`Amneal Pharmaceuticals LLC — Exhibit 1019 — Page 14
`
`
`
`15
`
`the sponsor
`During a follow-up teleconference,
`form tabulations.
`case report
`acknowledged the missing data and stated that they had determined some of the data to be
`not useful due to unavailability of CRF's or the omission of data from CRF’s . They
`were told to immediately provide as much. of the data as possible and written
`explanations for any data which would not be submitted. These final portions of the
`safety database have been submittedpiecemeal since that time.
`In her first addendum to
`the medical review, Dr. Hartwell has evaluated this late data in full and carefully
`delineates
`the various parts, based on GCP suitability, availability of primary
`documentation, and overall importance to the safety profile of dexmedetomidine.
`
`In an attempt to incOrporate the recently submitted data into the exposure database, Dr.
`Hartwell created two tables [see pages 5 and 6 of her first addendum] which surrunarize
`the number of studies and the number of patients included in the supplemental ISS,
`broken down by GCP suitability and by those with available CRF’s.
`She then
`incorporated the patients from the supplemental submissions into a table [page 6 of her
`first addendum] of all exposed patients, updating Dr. Cortinovis’ Table 32 [page 5 7 of his
`review]. At this time, based on the information available from the sponsor, it appears that
`a total of 3338_ subjects have been exposed to dexmedetomidine in clinical studies.
`However, the sponsor has categorized 11 Phase I studies (109 subjects) and 4 Phase II/III
`studies (146 subjects) as containing inadequate information; and this data was not
`included in the supplemental 158. Thus, the overall ISS database includes 3083 subjects
`exposed to dexmedetomidine.
`-
`
`
`
`Extent of exposure by close is summarized in the table below, based on Dr. Cortinovis’
`Tables 7 and 22 [pages 24 and 47, respectively, of his review] and Dr. Hartwell’s Tables
`..
`4 and 5 [page 7 of her first addendum]:
`
`APPEARS THIS WAY
`ON ORIGINAL
`
`Dexmedetomidine
`NDA 21-038
`
`Petition for Inter Partes Review of US 8,242,158
`Amneal Pharmaceuticals LLc — Exhibit 1019 — Page 15
`
`
`
`'
`
`" if
`_..,.,.._.._é.,,..,.,u_‘:
`Phase 1 Studies:
`Mean Total Dose
`N
`
`,
`'
`
`(pg/kg) 1 SD
`—_—.—__
`Mean Total Duration
`N
`
`(hr) 1 SD
`Minimum
`Maximum
`
`'
`
`_
`
`'
`
`IM
`Rapid
`Continuous
`Administration
`Infusion
`Infusion
`"ET-‘5‘ ‘3"-e‘Fi'J‘i‘ :3 ' I.
`i
`i
`I
`i
`i
`h"
`
`r
`
`I
`
`I74
`
`3.52 i 3.97
`
`174
`7.65 :t 8.26
`.
`
`-
`
`167
`0.13 1: 0.05
`0.02
`
`Mean Total Duration
`N
`
`(hr) 1- SD
`Minimum '
`Maximum
`
`1475
`
`10.10 i- 654
`0.02
`
`106
`
`0.05 i 0.03
`0.02
`
`
`
`During her review of the safety data Dr. Hartwell requested more specific information on
`exposure by dose and duration from the sponsor. Dose by duration exposure data for all
`treated patients in the Phase II/III continuous infusion studies is summarized in Dr.
`Hartwell‘s Table] from page 2 of her second addendum:
`
`Mean Total Dose
`
`N (
`
`Pg/k8) 1 SD
`Mean Total Duration
`N
`1-; 23‘.
`
`(hr) i SD
`
`NB. The total N for all patient/subject listings in this table does not equal the total N for the safety
`database. We "total N here falls between the total N for patients exposed and the total N for patients in the
`database (those with adequate and available data). bued on availability of dose and duration information
`from the different study sites.
`
`':
`'
`
`Dexmedetornidine
`NDA 21-038
`
`Petition for Inter Partes Review of US 8,242,158
`Amneal Pharmaceuticals LLC — Exhibit 1019 — Page 16
`
`
`
`unnnnn-I“ IE-
`munnnnu-I"
`mun-Immun-
`nun-“unnum-
`“nun-Inn“
`nunnnnnnn .m-
`nuunnnun‘
`“mm-“unun-EI
`“mun-nu“m.
`unnuunnnn“
`nunununn-a-
`nun-mum.-“
`“unuunn-I“
`- unnuunnu-n“
`nun-unnu-i-I-n
`nnnnnnnmn
`mmuuu‘
`From Sponsor‘s Table of Duration by Dose, Supplementto NDA. [0-27-99. Exhibit 4
`NB. The tetal N corresponds to the total number of patients with available tout! duration data as in my Table 9. above. However.
`there was a discrepancy in the total N between the sponsor's 185 Supplement (submitted August 16. 1999). Appendix C, Table
`2.l.2. p. 68 and Supplemental Information submined on October 27, 1999 (p. 7). This discrepancy of 2 patients appears to be a
`simple error in addition.
`
`
`
`Deaths:
`
`Amongst the 3083 dexmedetomidine treated patients, there were 12 deaths in the Abbott
`sponsored clinical studies and 1 death in \——-—-——-——-———-_'- :ported to the
`
`Dexmedetomidine
`NDA 21.038
`
`Petition for Inter Partes Review of US 8,242,158
`Amneal Pharmaceuticals LLC — Exhibit 1019 — Page 17
`
`Table 10. Extent of Exposure — Frequency of Duration by Dose
`Phase IUIII Continuous Infusion Studies — All-Treated Patients
`
`—m
`
`Do'se by duration exposure data for all treated patients in the Phase 1 continuous infusion
`studies is summarized in Dr. Hartwell’s Table 1 from page 1 of her second addendum:
`
`Table 11. Extent of Exposure - Frequency of Duration by Dose
`Phase 1 Continuous Infusion Studies - All-Treated Patients
`
`—n
`
`un-.“n
`nun-u"
`“nununn
`“unnnnn-m
`“nun-“nu
`mun—nun“
`“nu-“nu.-
`“nuunnnn
`uuunnnn-r-
`“nu-.“u
`“nun-“mun
`“ll—n.-
`From Sponsor's Table of Duration by Dose. Supplement to NDA. I0-27-99. Exhibit l
`NB. The total N corresponds to the total number of patients with available total duration data as in my Table 9. above.
`
`
`
`l8
`
`original NDA [total deaths equals 16 with the additional deaths reported during the
`review period; see below].
`In all or the studies combinedkthere were 8 deaths in the
`placebo groups (N = 1495) and none in the comparator groups (N l= 407) reported to the
`original NDA.
`
`Dr. Cortinovis has summarized the 12 Abbott deaths in his review and Dr. Hartwell has
`
`:1 in her addendum.~~While there were no deaths that
`;
`summarized '
`could clearly be attributed directly to dexmedetomidine, a few of the cases raise concerns
`regarding intraoperative or postoperative cardiovascular events which may have,
`ultimately, contributed to the patients’ deaths.
`'
`
`1
`
`
`
`Patient 10202, Study W97-246, was a 74 year old male who underwent
`coronary” artery
`bypass
`surgery
`and
`developed
`hypotension
`postoperatively, soon after the dexmedetomidine infusion was started.
`Episodes of hypotension continued and the study drug was discontinued 9
`hours—alter initiation. The patient then developed renal insufficiency, but
`was reportedly stable over the next 3 days. He then suffered an acute
`myocardial i