FDA Briefing Document

 

Blood Products Advisory Committee Meeting

 

May 1-2, 2008

 

 

 

 

 

 

 

 

 

Cinryze^TM (C1-esterase Inhibitor (Human) Nanofiltered (C1INH-nf)

 

 

Lev Pharmaceuticals, Inc.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Basil Golding, MD

Division of Hematology

OBRR/CBER/FDA

 

TABLE OF CONTENTS

PAGE

 

1.0       GENERAL INFORMATION                                                                                       3  

 

                        PRODUCT NAME

                        PRODUCT COMPOSITION

                        PROPOSED INDICATION

                        PROPOSED AGE GROUP

                        DOSING REGIMEN AND ROUTE OF ADMINISTRATION

 

                        EXECUTIVE SUMMARY                                                                   5

 

2.0       INTRODUCTION AND BACKGROUND                                                     7

 

2.1       REGULATORY BACKGROUND                                                                  9

 

2.3       BASIS FOR LICENSURE                                                                               10

 

3.0       CLINICAL OVERVIEW                                                                                13

 

3.1       EFFICACY – PIVOTAL STUDIES                                                               17

 

3.2       IMMUNOGENICITY                                                                                                 24

 

3.3       SAFETY                                                                                                            25

 

3.4       STATISTICAL REVIEW                                                                                 28

 

 

APPENDIX 1             Adverse Events in prior studies                                                 32

APPENDIX 2             Adverse Events in 2005-1 Part A                                              34

APPENDIX 3             Adverse Events in 2005-1 Part B                                              35

APPENDIX 4             Viral Inactivation/Removal                                                        39

1.0              GENERAL INFORMATION

 

 

Product name

 

Established name:                   C1-esterase Inhibitor (Human) Nanofiltered (C1INH-nf)

 

Proposed trade name:             Cinryze^TM

 

Product composition (from the Applicant’s proposed label):

 

Cinryze^TM is a sterile, stable, lyophilized preparation of highly purified C1 inhibitor derived from human plasma.  Cinryze is manufactured from human plasma purified by a combination of filtration and chromatographic procedures. The specific activity of Cinryze is ≥ 4.0 U/mg. The purity is

≥ 90% human C1 inhibitor. Following reconstitution with 5 mL of Sterile Water for Injection, USP, each vial contains approximately 500 U of functionally active C1 inhibitor.  It has a pH between 6.6 and 7.4 and an osmolality between 200 - 400 mosmol/kg. One Unit (U) of Cinryze corresponds to the mean quantity of C1 inhibitor present in 1 mL of normal fresh plasma.

 

The manufacturing process for Cinryze includes processing steps designed to reduce the risk of viral transmission. Screening against potentially infectious agents begins with the donor selection process and continues throughout plasma collection and plasma preparation. Each individual source plasma donation used in the manufacture of Cinryze is collected only at FDA-approved blood establishments and is tested by FDA licensed serological tests for Hepatitis B Surface Antigen (HBsAg), and for antibodies to Human Immunodeficiency Virus (HIV-1/HIV-2) and Hepatitis C Virus (HCV). Additionally, all plasma used in the manufacture of this product was tested by FDA-licensed Nucleic Acid Tests (NAT) for HCV and HIV-1 and found to be non-reactive (negative).

 

Two dedicated, independent and effective viral reduction steps are employed in the manufacture of Cinryze: heat treatment at 60°C for 10 hours in an aqueous solution with stabilizers, and nanofiltration through two sequential 15 nm Planova filters. These viral reduction steps, along with a step in the manufacturing process, PEG precipitation, have been validated in a series of in vitro experiments for their capacity to inactivate/remove a wide range of viruses of diverse physicochemical characteristics including: Human Immunodeficiency Virus (HIV), Hepatitis A Virus (HAV), and the following model viruses: Bovine Viral Diarrhea Virus (BVDV) as a model virus for HCV, Canine Parvovirus (CPV) as a model virus for Parvovirus B19, and Pseudorabies Virus (PRV) as a model virus for Hepatitis B Virus (HBV).

 

 

Manufacturer:                         Lev Pharmaceuticals under contract to Sanquin Blood Supply Foundation (The Netherlands)

 

Proposed indication:               C1 Inhibitor replacement therapy for use in patients with Hereditary Angioedema (HAE) to prevent attacks.

 

 

Dosing regimen:                      A dose of 1000 U Cinryze is recommended to be administered twice weekly for long term preventive replacement therapy of C1 inhibitor in HAE patients.        

 

Route of administration:         Intravenous

 

Potency:                                  Approximately 500 U/vial. Two vials are combined to make a single dose. Each single-use vial contains the following excipients: 4.1 mg/mL sodium chloride, 21 mg/mL sucrose, 2.6 mg/mL trisodium citrate, 2.0 mg/mL L-Valine, 1.2 mg/mL L-Alanine, 4.5 mg/mL L-Threonine when reconstituted with the appropriate amount of diluent

 

EXECUTIVE SUMMARY

 

This briefing document contains a summary of efficacy and safety data provided by Lev Pharmaceuticals, Inc. to support approval of Cinryze^TM, C1-esterase Inhibitor (Human)  Nanofiltered (C1INH-nf) indicated for the prevention of hereditary angioedema attacks.  Cinryze^TM is to be administered twice weekly to pediatric or adult hereditary angioedema patients. The proposed release specification potency is 500 U/vial, with a shelf-life of 2 years when stored at 2°C–25°C (36°F-77°F).

 

The Biologics Licensing Application (BLA) contains the following two adequate and well-controlled U.S. studies conducted under IND ------:

 

1) LEVP 2006-5 [phase 1 for pharmacokinetics and safety] and

2) LEVP 2005-1 [phase 3, Part A: treatment of HAE attacks, Part B: prophylaxis of HAE attacks]. 

 

This briefing document will only discuss LEVP 2005-1 Part B (prophylaxis of HAE attacks).   LEVP 2005-1 Part A (treatment of HAE attacks) is still under review by FDA.

 

 

 

Efficacy

 

Efficacy was evaluated in study 2005-1 Part A for treatment of hereditary angioedema (HAE) attacks, and in 2005-1 Part B for prophylaxis of HAE attacks.

 

Part A (treatment of HAE attacks) is still under review by FDA and will not be discussed at this Advisory Committee.

 

Part B (prophylaxis of HAE attacks) demonstrated efficacy in reducing the frequency of HAE attacks to varying extents in a randomized, blinded prophylaxis study comparing Cinryze^TM to placebo. In a pre-specified Analysis of Variance (ANOVA), with each individual serving as his/her control, the reduction in frequency of attacks per unit time comparing the treatment and placebo periods was highly significant (p < 0.0001). Upon review of individual subject response data, there was an aggregate 50% reduction in the frequency of HAE attacks during a 90 day active prophylaxis period compared to a 90 day placebo prophylaxis period.  Although most individuals experienced some decrease in frequency of attacks, individual responses to Cinryze^TM prophylaxis were variable and ranged from a 100% reduction in the frequency of HAE attacks to an 85% increase in the frequency of HAE attacks in one subject.   

 

No dose finding studies were conducted to support the recommended dose schedule for prophylaxis, which was 1000 units intravenous, 2 or 3 times per week. Dosing was based on published reports of the clinical use of C1 esterase inhibitor replacement therapy.  FDA proposes the performance of postmarketing studies to evaluate dosing regimens.

 

Immunogenicity

 

Immunogenicity to Cinryze^TM was assessed by measuring serum anti-C1INH antibodies at baseline and at various times after dosing for Part A and Part B. The first central laboratory reported many samples as positive. However, repeat testing of samples at the same laboratory produced inconsistent results. Two subsequent laboratories tested subsets of the samples and reported them as negative. There was no definite evidence linking the putative antibodies determined in the first laboratory, with adverse events or reduced efficacy of Cinryze^TM.  FDA proposes postmarketing studies to evaluate this issue further.

 

Safety

 

The safety profile of Cinryze^TM when used for prophylaxis at the recommended dose schedule appears to be acceptable.  Adverse events that were noted were likely due to intercurrent illnesses and the underlying disease rather than due to Cinryze^TM.  There were no deaths and no adverse events that led to study discontinuation.  There were 4 subjects with treatment-emergent serious adverse events (laryngeal edema, resolved; lymphadenopathy, resolved; severe hereditary angioedema, resolved with sequelae; and moderate hereditary angioedema, resolved).  FDA proposes post marketing safety monitoring to evaluate the effects of repeated and long-term treatment.

 

Conclusion

 

Cinryze^TM at a potency of 1000 U i.v. two to three times per week was effective in reducing the frequency of hereditary angioedema attacks in subjects with hereditary angioedema. The safety profile of this prophylactic dose schedule of Cinryze^TM appears to be acceptable.  The immunogenicity of Cinryze^TM at this dose schedule remains to be evaluated.

 

2.0              INTRODUCTION AND BACKGROUND

 

C1 Esterase Inhibitor (C1INH) is a 104 kD plasma glycoprotein (35% carbohydrate) that was first described in the late 1950’s as the plasma activity that inhibits the C1 proteinase activity of the complement cascade.  It appears to be the only inhibitor of C1 esterase. Subsequent research demonstrated that it is a more general proteinase inhibitor of the serpin class, having inhibitory activity against C1r, C1s, kallikrein and Factor XIIa.  In vitro, it inhibits plasmin.  However, it does not appear to be a significant inhibitor of plasmin in vivo.

C1 esterase inhibitor has the following activities, as shown in the following diagram:

·         inhibition of the classical complement cascade,

·         inhibition of  coagulation factors XIa and XIIa

·         inhibit of the conversion of plasminogen to plasmin

·         inhibition of activated kallikrein in the kallikrein-bradykinin pathway.

From J Am Acad Dermatol  53(3):373-88 (2005)

 

Upper figure: diagrammatic representation of plasma kinin-forming cascade indicating steps inhibitable by C1INH. All functions of factor XIIa and kallikrein are affected. Lower figure: further digestion of factor XIIa by kallikrein and plasmin generates factor XII fragment (XIIf), which initiates the complement cascade. Both factor XIIf and C1 are inhibited by C1INH.

 

Hereditary Angioedema.

 

From A.L. Sheffer, M.D., J Allergy Clin Immunol 120:756-757 (2007):

 

Hereditary angioedema (HAE) is an autosomal-dominant condition [chromosome 11], characterized by episodic self-limited, occasionally life-threatening attacks of angioedema. Affected individuals lack sufficient functional inhibition of the first complement protein, the serine proteinase inhibitor C1INH. In most instances, the C1INH is absent (type I), but 15% of affected individuals may possess a nonfunctional C1INH (type II). These 2 types of HAE cannot be distinguished clinically. The incidence varies from 1:10,000 to 1:50,000 persons. The biological role of the C1INH is to regulate the intrinsic and contact coagulation pathways as well as the complement system. In the former, plasma kallikrein and coagulation factors XIa and XIIa (Hageman factor) are inhibited, and in the latter, C1r and C1s are inhibited. When C1INH is deficient or absent, bradykinin is released from the high-molecular weight kininogen by plasma kallikrein in abnormally high amounts. Experiments with C1INH knockout mice have confirmed that increased vascular permeability in HAE is mediated by bradykinin via the contact system.

 

2.1              REGULATORY BACKGROUND

 

There are no U.S. licensed C1 Esterase Inhibitor products at the present time.

 

The following summarizes the regulatory chronology of this BLA:

 

13-May-2004  Pre-IND meeting on manufacturing and clinical trial design

27-Jul-2004     Pre-IND meeting on manufacturing and clinical trial design

28-Jul-2004     IND ------ submitted

16-Jan-2004    Orphan designation was granted for "treatment of angioedema."

07-Jan-2005    Telecon on conformance lots, request for permission to do PK in phase 4, and viral safety testing

01-Feb-2005    Telecon on viral safety testing

30-Oct-2005    Fast Track designation granted

21-Jun-2007    Pre-BLA telecon on assay problems

31-Jul-2007     STN125267 submitted

14-Aug-2007   Review Committee formed

15-Aug-2007   Priority Review granted

25-Sep-2007    FDA information request faxed to sponsor (data vetting, observation times, response modeling request, CMC, clinical pharmacology, labeling)

29-Sep-2007    Filing Date

17-Oct-2007    Sponsor’s response to 25-Sep-2007 FDA fax [see Appendix 2]

29-Oct-2007    Sponsor submits results of Part B (prophylaxis)

27-Nov-2007   Sponsor’s response to 07-Nov-2007 FDA fax

30-Jan-2008    First Action Due Date

 

 

 

2.2              BASIS FOR LICENSURE

 

The applicant conducted a phase 3 study 2005-1 composed of two parts, 1) Part A for treatment of HAE attacks in 71 subjects with hereditary angioedema, and 2) Part B for prophylaxis of HAE attacks in 22 subjects who had completed participation in Part A.

 

In addition, the applicant conducted a randomized, parallel group open label pharmacokinetics study 2006-5 in subjects with hereditary angioedema.

 

2005-1 Part A (treatment of HAE attacks) is still under FDA review, and will not be discussed before this Advisory Committee.

 

2005-1 Part B (prophylaxis of HAE attacks) demonstrated safety and efficacy for the prophylaxis indication, and is discussed below.

 

2.21     Brief Synopsis of Study Procedures for Part A

and for Part B

 

Enrolled subjects who completed Part A (treatment of acute attacks), and who demonstrated a high frequency of HAE attacks (2 or more per month) were randomized to 12 wks prophylaxis with either C1INH or placebo (infused at study site), followed by a cross-over to 12 wks prophylaxis with the other study agent.  HAE attacks of any severity were recorded. Subjects in either arm received open label C1INH, 1000 U, if treated during acute attacks while on the prophylaxis part of the study. Since enrollment in the prophylaxis study (Part B) depended on participation in Part A (treatment of acute attacks), the study procedures for Part A are described below:

a.                  Subjects are screened to confirm the diagnosis of HAE and to establish a baseline C4 level.

b.                 Subjects who meet the eligibility criteria are enrolled and wait for the first HAE attack meeting the treatment eligibility criteria.

c.                  When an eligible HAE attack occurs, the subject travels to the treatment site and must be treated within 4 hour of the attack onset to remain eligible.  There were 71 subjects with an eligible HAE attack that was treated.

d.                 Subjects designate a “defining symptom” from among the following 3 categories: facial, gastrointestinal, or genitourinary and a serum C4 level is measured for comparison with the serum C4 level at screening.

e.                  Subjects are monitored every 15 minutes for 8.5 hours to record response data.

f.                  Treated subjects are retrospectively entered into the data analysis set if the serum C4 level at treatment start is lower than the serum C4 level at screening, thereby confirming the presence of an HAE attack. Anomalous serum C4 results (HAE subjects should have normal C4 levels at baseline with a decreased level at the time of an attack) caused the sponsor to use a “judiciary” to examine the data for 23 of 71 subjects to decide whether they should be included in the data analysis set.  The judiciary ruled that 20 of the 23 subjects should be included.

g.                 Due to some subjects exhibiting low C1q levels, as measured by the central laboratory (a normal C1q level in HAE was an eligibility criterion), the central laboratory was changed 3 times during the pivotal study.  Also, the method used for measurement of serum C4 was changed during the study.

h.                 Part B (prophylaxis) enrolled subjects who had completed Part A, and who had demonstrated a high frequency of HAE attacks.  Subjects were randomized to 12 wks prophylaxis with either C1INH or placebo (infused at study site), followed by a cross-over to 3 months prophylaxis with the other study agent.  HAE attacks of any severity were recorded.

i.          Presence of abnormally high levels of antibody against C1INH

            was an exclusion criterion.     

 

Due to aberrations of laboratory determinations of complement and

antibody against C1INH, patients were enrolled and then adjudicated for

diagnosis (if C4 levels did not decline during acute attack) and granted a

waiver (if baseline antibody levels were high but restested negative).  This

involved 10/22 patients in Part B.

 

2.22.    Safety Monitoring

 

In Part A (treatment of HAE attacks), subjects were monitored at the clinical site for 12 hours after treatment.  If HAE attack symptoms persisted, subjects could be hospitalized until complete resolution of symptoms, if necessary.  Subjects were contacted by telephone 72 hours after treatment to obtain follow up information on HAE attack parameters (e.g. time to complete resolution) and for adverse events. 

 

In Part B (prophylaxis of HAE attacks), subjects received prophylaxis treatments 2 or 3 times a week at the clinical site.  Adverse event information was collected at each visit.  In addition, subjects were given diary cards to record information on HAE attacks and adverse events.  Subjects were contacted at least once a week by telephone and were questioned about HAE attacks and adverse events.  All subjects had a follow up visit 3 months after the final prophylaxis treatment to provide a blood sample for evaluation of viral safety.

 

2.23.    Pharmacokinetic Study: 2006-5

 

Pharmacokinetics (PK) were performed as a randomized, parallel group, open label

study in 27 subjects (1 to 46 years of age) with hereditary angioedema (HAE).

The subjects received either 1 dose (1000 units Cinryze IV; n = 13) or 2 doses (1000 units dose followed by a second 1000 units dose one hour later; n = 14).  Blood samples were taken before dosing and at regular intervals for 168 hours (5 minutes, 1, 3, 6, 24, 48, 96, and 168 hours).  Plasma concentrations of antigenic C1 inhibitor, functional C1 inhibitor, and C4 antigen were measured for PK evaluation. 

 

The following table summarizes the PK parameters of Cinryze (functional C1 inhibitor):

 

Table 1: Pharmacokinetic parameters of Cinryze (functional C1INH), mean ± SD

Parameters	Single Dose (n = 13)	Double Dose (n = 14)
Cbaseline (U/mL)	0.31 ± 0.20	0.33 ± 0.20
Baseline corrected Cmax (U/mL)	0.37 ± 0.15	0.51 ± 0.19
Baseline corrected AUC(0-∞) (U*hr/mL)	24.5 ± 19.1	39.1 ± 19.9
CL (mL/min)	0.85 ± 1.07	1.17 ± 0.78
Half-life (hours)	56 ± 36	62 ± 38
Mean residence time (MRT) hrs	84 ± 50	91 ± 52

 

Plot of Cinryze plasma concentrations vs. time (functional C1INH activity)

 

 

FDA Conclusions:

 

The PK of Cinryze in subjects with HAE indicates that the drug has a long half-life and slow clearance. Administration of the second dose of Cinryze 60 minutes after the first dose did not follow linear kinetics (C_max and AUC were not dose proportional).  The long half life indicates that a dose schedule of 2 administrations per week is reasonable and would likely result in C1INH levels > 40% of normal which are considered sufficient to prevent attacks.

 

3.0       CLINICAL OVERVIEW OF PART B, PROPHYLAXIS

 

Study Objectives and Endpoints

 

The objective of this Part B study was to investigate efficacy and safety of Cinryze™ as a prophylactic treatment to prevent HAE attacks (Part B). 

 

The primary endpoint for Part B was the number of attacks of HAE during each treatment phase (normalized for the number of days the subject participated in this phase), using each subject as his/her own control. The normalized number of attacks was calculated by dividing the total number of attacks in each period by the number of days the patient was in that period.

 

The secondary efficacy endpoints for Part B were the number of subjects dropping out at each treatment period, average severity of attacks, average duration of attacks, number of open-label C1INH-nf infusions, and change from baseline in C1INH antigenic and functional levels.

 

The following tables present information on the clinical studies that have been conducted with Cinryze^TM.

 

Only the efficacy results of study 2005-1 Part B (prophylaxis of HAE attacks) will be presented at the May 2, 2008, Blood Products Advisory Committee meeting.

 

It should be noted that there were no adequate and well-controlled studies of Cinryze™ or the European product version, CETOR, prior to study 2005-1.  The European product version of Cinryze™ was licensed based on data from a pharmacokinetics study. --------------------------- --------------------------------------------------------------------------------------------------------------------------------------------------------

 

 

 

 

 

 

Table 2:  Completed Safety and Efficacy Studies with Cinryze (C1INH) Conducted by Lev Pharmaceuticals, Inc. (Part A)

 

Study Number Drug Indication	Study Design	Dose	Placebo	Cinryze	Open Label Cinryze Onlya	Safety	Efficacy
LEVP 2005-1 PART/A Cinryze HAE	Phase III, multi-center, randomized, placebo- controlled, double- blind study to evaluate the efficacy and safety of Cinryze (C1INH-nf) as a therapeutic agent for acute attacks of HAE	Cinryze: 1000 U or 2000 U	Randomized: 35 subjects   As Treated b 34 subjects M:6    F: 28 Age: 9-64 years   Safety: 35 M:7 F:28 Age9-64 Years	Randomized: 36 subjects   As Treatedb: 37 subjects M:10 F: 27 Age: 6 -75 Years   Safety: 36 M:9 F:27 Age:6-75 Years	12 subjects     M: 6 F: 6   Age: 9 -73 Years   Safety: 12 M:9 F:27   Age:6-75 Years	AEs clinical laboratory, vital signs local tolerance antigenicity viral serology	Primary: Time to the beginning of unequivocal relief   Secondary: Percentage of subjects who had unequivocal beginning of relief within 4 hours following treatment; time to complete resolution of the attack; effects of treatment on CIINH and C4 levels.

^a Subjects treated for non-randomizable attacks only. Randomized subjects could also receive Cinryze for non-randomizable attacks prior to or after the attack evaluated in the double-blind part of the study

^bSubject 22-001 randomized to the placebo treatment group received ClInh-nf in error at 60 minutes. Therefore, he was included in the Cinryze treatment group in the “As Treated” population.

 

This study was submitted to the FDA as Part A and is currently under review.
Table 3: Completed Safety and Efficacy Studies with Cinryze (C1INH) Conducted by Lev Pharmaceuticals, Inc. (Part B)

 

Study Number Drug Indication	Study Design	Dose	Study Population	Open Label Cinryze Only	Safety	Efficacy
- LEVP 2005-1 PART/B Cinryze HAE	Phase 3, multicenter, randomized, placebo-controlled, double-blind cross-0ver study to evaluate the efficacy and safety of Cinryze (C1INH-nf) for prevention of acute attacks of HAE	Cinryze: 1000 U or Placebo (2 infusions per week) in 2 12-week periods	Randomized and Treated: 24   Placebo/Cinryze: 12   Cinryze/Placebo: 12	2 subjects  M: 0 F: 2 Age: 4l- 53	AEs, clinical laboratory, vital signs, antigenicity, viral serology	Primary: -Number of attack of angioedema   Secondary: -Number of withdrawals -Total number of days of swelling -Average severity of attacks, -Average duration of attacks, -Number of open label Cinryze infusions, -Average number of days of swelling, Effect of treatment on C1INH levels
			Efficacy Dataset 22 Subjects M:2 F:20   Age:9-73 Years
			Safety Dataset (randomized):24 M:3 F:21   Age:9-73 Years	Safety: 2 subjects

 

This is the prophylaxis study submitted to the FDA as Part B, and is the subject of this BPAC presentation.
Table 4:  Completed Clinical Pharmacology Studies with Cinryze (C1INH) Conducted by Lev Pharmaceuticals, Inc.

 

Study Number Drug Indication	Study Design	Dose	Treated Demographics	Safety Data	Other Outcomes
LEVP 2006-5 PART/B Cinryze HAE	Phase 1, randomized, parallel-group, open-label study to compare the PK of a single dose of Cinryze (C1INH-nf) to that of 2 doses	Cinryze 1 or 2 doses at 1000 U	27 subjects 1 dose (13 subjects) 2 doses (14 subjects) M:10 F:17 Age:19-57 Years	AEs, clinical laboratory, vital signs, and virology	PK of antigenic and functional C1INH-nf: PK of C4

 

This is the PK study described in the text (see above 2.23)

 

 

Table 5:  Ongoing Safety and Efficacy Studies with Cinryze (C1INH) Conducted by Lev Pharmaceuticals, Inc.

 

Study Number Drug Indication	Study Design	Dose Duration	Enrolled Treated Demographics	Safety Data Data Available as of 25 Sep 2007	Efficacy
LEVP 2006-1 HAE	Phase 3, multi-center, open-label study of CinryzeTM (C1INH-nf) for the treatment of HAE attacks	Cinryze: 1 or 2 infusions 1000 U /infusion	67 subjects 67 subjects M:18 F:49 Age: 7-81 Years	SAE s	Number of subjects with unequivocal beginning of relief within 4 hours. Time to the unequivocal beginning of relief, change in time to the unequivocal beginning of relief C1INH and C4 levels.
LEVP 2006-4 HAE	Phase 3, multi-center, open-label study that will evaluate the efficacy and safety of Cinryze (CIINH-nf) as prophylaxis to prevent HAE attacks.	Cinryze : 1000 U every 3 to 7 days	46 subjects 46 subjects M:5 F:41 Age:5-75 Years	SAE s	Number of attacks PK/PD analyzed under separate protocol

 

 

These studies are under IND and facilitate access to the product in the USA.
3.1       EFFICACY – PIVOTAL STUDY Part B – Prophylaxis of HAE Attacks

 

Study 2005-1 Part B was a pivotal study of the use of Cinryze^TM for prophylaxis of HAE attacks.  Subjects for Part B were selected from among subjects who had completed study 2005-1 Part A, treatment of HAE attacks.  Subjects who reported a history of a high frequency of HAE attacks (2-3 per month) were enrolled into Part B.

 

Subjects in Part B were randomized to receive intravenous treatments 2 to 3 times per week for 12 weeks with 1000 U Cinryze^TM or a matched dose of placebo, administered at a clinical site under a blinded clinical trial design.  At the end of the 12 week prophylaxis period, subjects were crossed over, without a washout period, to the other prophylaxis arm (Cinryze^TM or placebo) for an additional 12 week period.  Subjects in either arm received open label C1INH if treated during acute attacks, 1000 U, while on the prophylaxis part of the study. Subjects recorded the incidence and severity of all HAE attacks experienced during each prophylaxis period in a diary or reported at a scheduled visit.

 

The actual length of the period of prophylaxis varied among subjects and treatment periods, but was approximately 12 weeks.

 

Sponsor’s Efficacy Analyses: Part B

 

Primary

 

The primary efficacy endpoint for Part B was the number of attacks of angioedema during each treatment period, normalized for the number of days the subject participated in that period. This was done by dividing the total number of attacks in each period by the number of days the patient was in that period. An attack is defined as the subject-reported indication of a new swelling at any body location following a report of no swelling at that body location on the previous day.

 

Secondary

 

The secondary efficacy endpoints for Part B were:

 

•           number of subjects dropping out at each treatment period.

•           average severity of attacks. (The severity of an attack was the highest value assigned by the subject to any location at any day during the attack.)

•           average duration of attacks. (The duration of an attack was measured from the first report of swelling at any location until a subsequent report of no swelling at the same location.)

•           number of open-label C1INH-nf infusions.

•           change from baseline in C1INH antigenic and functional levels

 

Other Evaluations

 

The total number of days of swelling in each study period was compared between C1INH-nf and placebo.

 

 

 

 

Table 6: Part B – Results of prophylaxis of HAE attacks (n = 22)

 

Subject	Attacks on C1INH	C1INH Period Length (Days)	C1INH Attack Frequency (Attacks/Day	Attacks on Placebo	Placebo Period Length (Days)	Placebo Attack Frequency (Attacks/Day	Percent Reduction in Number of Attacks	Percent Reduction in Attack Frequency
06-001	0	81	0	6	85	0.07	100%	100%
12-005	0	34	0	7	96	0.07	100%	100%
24-001	0	81	0	14	82	0.17	100%	100%
59-001	0	83	0	14	80	0.18	100%	100%
16-004	2	84	0.02	22	96	0.23	91%	90%
12-012	1	82	0.01	9	86	0.10	89%	88%
07-001	2	81	0.02	13	83	0.16	85%	84%
16-003	2	81	0.02	12	85	0.14	83%	83%
53-002	2	81	0.02	9	81	0.11	78%	78%
06-018	2	85	0.02	8	82	0.10	75%	76%
51-001	8	81	0.10	20	82	0.24	60%	60%
13-002	10	85	0.12	19	86	0.22	47%	47%
53-003	7	82	0.08	14	93	0.15	50%	43%
18-004	7	82	0.08	10	67	0.15	30%	43%
53-001	11	81	0.14	17	85	0.20	35%	32%
16-006	13	81	0.16	19	82	0.23	32%	31%
56-001	6	80	0.08	8	80	0.10	25%	25%
52-001	12	82	0.15	15	81	0.18	20%	21%
07-012	12	82	0.15	14	86	0.16	14%	10%
54-001	6	85	0.07	6	84	0.07	0%	1%
16-005	17	81	0.21	16	82	0.20	-6%	-8%
17-002	15	86	0.17	8	85	0.09	-88%	-85%

 

The sponsor has presented these outcomes (Table 7a) by pooling data within a prophylaxis period and reporting mean values for attack frequency comparing Cinryze^TM to placebo (6.1 vs. 12.7)  suggesting a 50% reduction in HAE attack frequency while on Cinryze^TM prophylaxis.

 

Table 7a: Results of Part B – Prophylaxis
(Sponsor’s Analysis)

 

Table 7b: Results of Part B – Prophylaxis
(Sponsor’s Analysis)

 

 

Table 7b is the pre-specified ANOVA using each individual as his/her control in the crossover study.  FDA has verified these calculations showing a highly significant treatment effect.  Sequence or period effects did not confound the results.  Even if 10/22 patients, showing aberrant C4 and/or antibody levels are excluded from the efficacy analysis, the treatment effect was statistically significant (p =0.0004).

 

As can be seen from Table 6, and the histogram below, treatment with Cinryze^TM  resulted in varying reductions in HAE attack frequency: 45 % (10/22) of individuals had a reduced attack frequency of  >75%; 32% (7/22) had intermediate reductions (25-75); and 18% (4/22) had modest reductions (1-25%) in attack frequency.  Two individuals (9%) had more attacks with Cinryze^TM than with placebo.

 

 

 

One explanation for the diversity in responsiveness could be that the dose used was not optimal.  At a pre-IND meeting in 2004 FDA recommended phase 2 studies that may have facilitated more optimal dosing for the phase 3 trial.  The sponsor declined, citing the rarity of the disease and the difficulty in conducting such phase 2 studies.

 

Efficacy: Secondary Endpoints

 

Among the secondary endpoints analyzed by the sponsor were number of drop-outs, average attack severity, average duration of attacks, number of open-label C1INH-nf infusions, change from baseline in C1INH antigenic and functional levels, total number of days of swelling in each study period.

 

Attack severity and attack duration are related to clinical benefit and appear to be relatively independent.  Other secondary endpoints – such as days of swelling and number of open label C1INH infusions -- appear not to be independent of the primary endpoint and the secondary endpoints relating to attack duration and severity.  In addition, the secondary endpoint of C1INH levels must be considered an unvalidated surrogate endpoint at this time.

 

For the secondary endpoints attack severity and attack duration the following tables give these results:

 

Attack Severity Scale

 

·         Mild – Events that were usually transient, required no special treatment, and did not interfere with the subject’s daily activities.

·         Moderate – Events that introduced some level of inconvenience or concern to the subject, and may have somewhat interfered with daily activities, but were usually ameliorated by simple therapeutic measures (may have included drug therapy).

·         Severe – Events that were unacceptable or intolerable, significantly interrupted the subject’s usual daily activity, and required systemic drug therapy or other treatment.

Table 8: Average Severity of HAE Attacks

During Prophylaxis Period

 

Table 9: Average Duration (Days) of HAE Attacks

During Prophylaxis Period

 

FDA Comment

 

FDA analyzed these data (see below under 3.4 FDA Statistical Review) and

found that for the secondary endpoints, treatment with Cinryze^TM compared to

placebo reduced the severity and duration of attacks, and that these effects

were statistically significant.

 

A gender imbalance was noted over the course of the study. In Part A the C1INH arm had 36 subjects (27 female, 9 male), the placebo arm had 35 subjects (28 female, 7 male).  In Part B there were 2 males and 20 females.

  

The genetic defect is autosomal dominant, which predicts an even distribution between males and females.  One possible explanation for the imbalance of subjects enrolled in Part A is that females disfavor the current standard preventive therapy with attenuated androgens and might therefore be more likely to seek entry into clinical trials of new treatment and prophylactic therapies for HAE.  Additionally, estrogens predispose females to a higher frequency of attacks.  At screening for Part A the average time between attacks for enrolled subjects was reported as every 36 days for 69 males, and every 26 days for 168 females.  Selection in Part B was determined by an increased frequency of attacks in Part A. Thus the further selection of females in Part B could be explained on the basis that they experienced more frequent attacks. 

 

Given the clinical observations that females have more frequent and more severe HAE attacks than males, the demonstration of successful HAE prophylaxis in this study cohort of mainly female subjects is statistically significant (p < 0.0001). There is no reason to suspect that Cinryze would not be at least as effective in males, who typically have milder disease manifestations.

 

 

 

 

Efficacy Conclusion

 

Overall, FDA concludes that Cinryze^TM has been demonstrated to be effective for reduction of the frequency of HAE attacks when used for prophylaxis in persons with hereditary angioedema.

 

IMMUNOGENICITY

 

Immunogenicity was evaluated in Part A (treatment of HAE attacks) and in Part B (prophylaxis of HAE attacks). 

 

In Part A 93/329 subjects (28%) were antibody positive at screening or pre-infusion at the first laboratory used by the sponsor. However, repeat testing of samples at the same laboratory produced inconsistent results prompting analysis at alternate laboratories. Of these 329 subjects, 119 were tested at a second laboratory. Among these 119 subjects, 2 (0.8%) tested positive at the second laboratory, whereas 58 (49%) tested positive at the first laboratory.  A smaller number of samples (n = 11) were sent to a third laboratory and all tested negative, although 5 of 11 were positive in the first laboratory.

 

All 24 subjects in Part B were first enrolled in Part A. Of the 22 subjects who completed Part B, antibody results were obtained for 19 subjects at the end of Part B and/or at the 3 month follow-up. Of these 19 subjects, 10 exhibited a positive result for C1INH antibodies as reported by the first laboratory. Of these 10 subjects, 2 reported a positive result (bound and/or free Ab) at screening.

 

Of the remaining 8 subjects, 6 had modest elevations in antibody levels.  However, 2 subjects (Patients 59-001 and 16-005) appeared to have a notable antibody response. Since these are binding assays, not functional assays, it is not known whether these antibodies have neutralizing activity. The effect of this antibody response on treatment efficacy is difficult to assess. Patient 59-001 still showed a 100% reduction in attack frequency on Cinryze^TM, while Patient 16-005 showed an increase in attack frequency.

 

There was no evidence that the antibody levels correlated with adverse events or treatment effects of Cinryze^TM (Table 10, Appendices 2, 3).  Resolution of this issue may require post-marketing studies.

 

 

 

 

 

 

 

 

 

 

 

Table 10: Lack of Relationship between Positive anti-C1INH Antibody

Results at the First Laboratory and Percent Reduction in HAE Attack Frequency

 

 

 

3.3 SAFETY

 

Safety analyses were assessed using the following measures: extent of exposure, AEs, vital signs, physical examinations, and laboratory tests. All summary safety analyses were carried out using subjects included in the safety dataset.

 

After review of the submitted safety databases, we conclude there are no safety concerns for use of Cinryze for prophylaxis to prevent HAE attacks at the doses studied.

 

The safety data for study 2005-1 Parts A (treatment of HAE attacks) and Part B (prophylaxis of HAE attacks), and for other studies conducted with Cinryze or its earlier product versions, are attached in Appendices 2, 3, and 4.

 

Study 2005-1 Part A observed 32 adverse events that occurred in 18 of 71 subjects treated for an HAE attack (7 C1INH, 11 placebo), as shown Appendix 3.  There were no deaths and no serious adverse events.

 

Study 2005-1 Part B observed 117 adverse events in 21 of 22 subjects who completed both periods of the prophylaxis study. 

 

The higher rate of reported adverse events and the higher proportion of subjects who experienced an adverse event in Part B compared to Part A can be attributed to

1)      the much longer observation period for Part B (12 weeks) compared to Part A (12 h, or in hospital, and at 3 months follow up), and

2)      less intense monitoring for adverse events in Part A than in Part B (in which subjects returned to the clinic every 2 or 3 days for an infusion).

 

In study 2005-1 Part B (prophylaxis of HAE attacks), the attribution of adverse events to the treatment administered is complicated by the protocol provision for open-label treatment with C1INH once an HAE attack had occurred.  It is not unexpected that more adverse events were reported following administration of Cinryze since (i) Cinryze was administered open label at the time of an attack and at a time when adverse events related to the attack would be expected to occur and be reported; and (ii) because of open label use Cinryze was given more frequently than placebo (see Table 11 below).   

 

In study Part B, the sponsor appropriately attributes all adverse events to the study agent C1INH. An alternative approach is to attribute the adverse event to the agent that was administered immediately prior to the onset of the adverse event (i.e. treatment emergent adverse events).  Using this latter approach, the following table of adverse events can be derived:

 

Table 11:  Adverse Events by Organ System and by Previously Infused Study Agent

 (Number of Adverse Events, Number of Subjects experiencing the Adverse Event)

 

Organ System	C1INH-nf AE	C1INH-nf Subjects	Placebo AE	Placebo Subjects
Blood and lymphatic system disorders	2	2
Congenital, familial and genetic disorders	2	2
Eye disorders	1	1	1	1
Gastrointestinal disorders	7	6	4	3
General disorders and administration site conditions	3	3	1	1
Infections and infestations	29	12	17	10
Injury, poisoning and procedural complications	7	3	4	1
Investigations	2	1
Metabolism and nutrition disorders			1	1
Musculoskeletal and connective tissue disorders	6	5	1	1
Nervous system disorders	6	5
Psychiatric disorders			1	1
Reproductive system and breast disorders	1	1
Respiratory, thoracic and mediastinal disorders	4	4	4	3
Skin and subcutaneous tissue disorders	10	6	2	2
Vascular disorders	1	1
Grand Total	81	20	36	13

(see Appendix 3 for a list of the adverse events)

 

Although it would appear that there is an increased frequency of adverse events after Cinryze^TM administration, it must be re-emphasized that the study design and the provision for open label administration of Cinryze^TM after an HAE attack resulted in patients being exposed to Cinryze^TM more frequently than placebo (1190 Cinryze infusions vs. 526 placebo infusions).  When expressed as adverse events per infusion, the rates for Cinryze^TM and placebo are the same (0.068).

 

 

Serious Adverse Events

 

There were no deaths during study 2005-1 Part B.  There were 4 serious adverse events (SAEs) in study 2005-1 Part B (see Appendix 4 for details). The SAEs are summarized as follows:

Subject 51-001 SAE: HAE attack

SAE: Surgery for peri-auricular cyst and insertion of permanent subcutaneous port

The Investigator categorized these events as moderate in intensity and not related to study medication

 

Subject 53-003 SAE: HAE attack

The Investigator categorized this event as severe and not related to the study medication.

 

Subject 55-001 SAE: HAE attack

The Investigator categorized this event as moderate and not related to the study medication.

 

Subject 13-002 SAE: Laryngeal edema

The Investigator categorized this event as severe and not related to the study medication and related to HAE.

 

Safety Conclusion

 

The adverse events appear to be related to intercurrent illnesses and the underlying disease rather than being due to treatment with Cinryze^TM.  The small number of skin, hypotensive and pulmonary events, suggest that immune responses to the product, if they occurred, were not associated with typical hypersensitivity reactions. Therefore, Cinryze^TM appears to have an acceptable safety profile for prophylaxis of HAE attacks when administered according to the labeled dose schedule. However, since prophylaxis involves repeated and long-term treatment, post marketing safety monitoring may be required.

 

 

 

 

3.4 FDA STATISTICAL REVIEW

 

The Biologics Licensing Application (BLA) contains a well-controlled phase 3 study LEVP 2005-1 conducted under IND ------. The study consists of two parts to investigate the efficacy and safety of C1INH-nf for the treatment of Hereditary Angioedema (HAE) in acute attacks (Part A) and a prophylactic treatment to prevent HAE attacks (Part B). This statistical briefing document discusses only the results from LEVP 2005-1 Part B (prophylaxis of HAE attacks) study. 

 

Study Design

 

It is a Phase 3 multi-center, randomized, placebo-control, double-blind trial to confirm the efficacy of prophylactic C1INH-nf in the prevention of acute attacks of HAE in patients. Subjects were not to enter Part B until either they had completed their randomized treatment in Part A or Part A had ended. Each subject was randomized to receive either 12 weeks of C1INH-nf followed by 12 weeks of placebo, or 12 weeks of placebo followed by 12 weeks of C1INH-nf, administered at a clinical site under a blind.  At the end of the 12 week prophylaxis period, subjects were crossed over, without a washout period, to the other prophylaxis arm (Cinryze or placebo) for an additional 12 week period.   Subjects recorded the incidence and severity of all HAE attacks experienced during each prophylaxis period. The study enrolled 24 subjects. Two subjects did not go to the second period. The sponsor’s analysis was based on 22 subjects.

 

Study Objectives and Endpoints

 

The objective of this Part B study was to investigate efficacy and safety of Cinryze as a prophylactic treatment to prevent HAE attacks (Part B).  The primary endpoint for Part B was the number of attacks of HAE during each treatment phase (normalized for the number of days the subject participated in this phase), using each subject as his/her own control. The normalized number of attacks was calculated by dividing the total number of attacks in each period by the number of days the patient was in that period.

The secondary efficacy endpoints for Part B were the number of subjects dropping out at each treatment period, average severity of attacks, average duration of attacks, number of open-label C1INH-nf infusions, and change from baseline in C1INH antigenic and functional levels.

 

Results from Applicant

Summary statistics consist of frequencies and percentages of responses in each category for discrete measures and of means, medians, standard deviations, minimum and maximum values for continuous measures. All significance tests were two-sided with statistical significance at the 5% level.

 

 

Primary Endpoint: Number of HAE Attacks

 

Table 12: Summary statistics of Part B – Prophylaxis

 

 

For crossover analyses, a standard analysis of variance was performed with effects for treatment, period, and subject within treatment. The crossover analysis evaluating the number of attacks was based on Poisson assumption and used the SAS PROC GENMOD. All significance tests were two-sided with statistical significance at the 5% level. The difference in the number of attacks during treatment with Cinryze and treatment with Placebo was statistically significant.

 

Table 13: The crossover analysis evaluating the number of attacks

 

 

 

Efficacy Secondary Endpoints:

 

For the secondary endpoints attack severity and attack duration the following tables give these results:

 

 

Table 14: Average Severity of HAE Attacks. Attack Severity Scale:

1 = mild, 2 = moderate, 3 = severe

 

 

The p-value reported by the sponsor was p=0.006. Using the paired t-test, we found that the difference was statistically significant (p=0.0056)

 

Table 15: Average Duration of HAE Attacks (Days):

 

 

The p-value reported by the sponsor was p =0.0005. Using the paired t-test, we found that the difference was statistically significant (p=0.0023).

 

The applicant concluded that since the difference in the number of attacks during treatment with Cinryze™ and treatment with placebo was statistically significant, that efficacy had been demonstrated.

 

Reviewer’s comments and analysis

 

The applicant provided the reviewer with the datasets and SAS programs used in their statistical analysis. The SAS programs have been found correct. From the results obtained the by the reviewer, the difference in the number of attacks during treatment with Cinryze and treatment with Placebo was statistically significant.  Hence, the primary objective of the study has been achieved. The difference in secondary endpoints was also confirmed to be statistically significant.

 

Reviewer Overall conclusion

 

The efficacy results based on the Generalized Estimating Equations (SAS PROC GENMOD with Poisson distribution and log link function) were confirmed by the reviewer, who considered them to be appropriate for the analysis of the number of attacks. The reviewer concluded that the applicant demonstrated effectiveness of Cinryze^TM for reduction of the frequency of HAE attacks when used for prophylaxis in persons with hereditary angioedema.

 

 

 

 

 

 

 

 

3.4  QUESTIONS TO THE COMMITTEE

 

Question #1

 

Is the safety and efficacy evidence sufficient for approval of Cinryze^TM for prophylactic treatment of HAE?

 

Question #2

 

If the answer to Question #1 is yes, should post-marketing studies be performed to further evaluate the following:

 

a)      the optimal dose for prophylaxis in males and females

b)      immunogenicity

c)      long-term safety

 

 

 

 

 

 

 

Appendix 1.         Adverse Events in Studies conducted by Sanquin BSF using an earlier version of the product (CETOR) that is currently licensed in Europe

 

There were no deaths in studies conducted by Sanquin BSF using CETOR.

 

Adverse Events in Studies Conducted by Sanquin BSF

 

Subject ID	Treatment	AE Preferred Term or Verbatim	Severity	Relationship
036-005/Part A N = 9 AEs=1
RGG2	Cetor	Fatigue	unknown	unknown
KB97002-C1-INH N=22 AEs=17
101	Cetor	Mitral insuff Grade II III	mild	Not related
102	Cetor	Bleeding from wound of teeth extraction under anticoagulation	mild	Not related
		Headache	moderate	Not related
103	Cetor	Edema because of subcutaneous infusion of C1-INH	moderate	Not related
104	Cetor	Exanthema arms & thorax mild edema fingers, allerg.  react.  to streptokinase	moderate	Not related
		Slightly elevated levels of CL, G-GT, ALAT&CRP No clinical relevance.	mild	Not related
105	Cetor	Serious complaints during infusion due to Phlebitis	severe	Not related
107	Cetor	PTCA because of pending MI	severe	Not related
		Headache	mild	Not related
108	Cetor	At discharge ALAT outside normal range without clinical. relevance	mild	Not related
109	Cetor	Mitral insufficiency grade 2-3, diagnosed Through echo	moderate	Not related
110	Cetor	LD, G-GT and ALAT outside normal range, no clin. relevance	mild	Not related
		Mitral valve insufficiency grade 1 diagnosed through echo	mild	Not related
		Suspicion of hypercholesterolaemia	mild	Not related
111	Cetor	Mild allergic reaction to strepto exanthema, itching, edmea	severe	Not related
		ASAT&ALAT slightly outside normal range, no clinical. relevance	mild	Not related
112	Cetor	Phlebitis on site of infusion	mild	Not related
113	Cetor	Gastric complaints, subject has a history of gastic ulcers;	mild	Not related
		Reinfarction	severe	Not related
114	Cetor	Mitral valve insufficiency Grade 1-2	mild	Not related
115	Cetor	Mitralis insufficiency II-III, diagnosis through echocardiograrn	moderate	Not related
116	Cetor	300-400 mL blood loss due to reopening of puncture hole	severe	Not related
127	Cetor	Compartmental syndrome in upper leg a week before the infarction	moderate	Not related
128	Cetor	Phlebitis	mild	Not related
KB2003.01/Part A N=14 AEs=5
103		Injection Site Thrombosis	mild	unlikely
		Influenza	moderate	Not related­
		Hereditary Angioedema	severe	Not related
104		Influenza	moderate	Not related
		Hereditary Angioedema	moderate	Not related
106		Hereditary Angioedema	mild	Not related
319		Angioneurotic edema	mild	Not related
320		Angioneurotic edema	mild	Not related

 

Appendix 2.         Adverse Events reported for study 2005-1 Part A – Treatment of HAE Attacks

 

There were 32 adverse events in database “AE” that occurred in 18 subjects (7 C1INH, 11 placebo), as shown in the following table:

                                                                    No. of AEs (No. of Subjects)

 

Appendix 3.    Adverse Events in study 2005-1 Part B – Prophylaxis of HAE Attacks

Adverse Events by Organ System and by Previously Infused Study Agent

(Number of Adverse Events, Number of Subjects experiencing the Adverse Event)

Organ System	Adverse Event	C1INH-nf AE	C1INH-nf Subjects	Placebo AE	Placebo Subjects
Blood and lymphatic system disorders	Anemia	1	1
	Lymphadenopathy	1	1
Blood and lymphatic system disorders Total		2	2
Congenital, familial and genetic disorders	Hereditary angioedema	2	2
Congenital, familial and genetic disorders Total		2	2
Eye disorders	Blepharospasm			1	1
	Conjunctivitis	1	1
Eye disorders Total		1	1	1	1
Gastrointestinal disorders	Abdominal pain	1	1
	Constipation	1	1
	Diarrhea	1	1
	Gastrointestinal pain			1	1
	Gastroesophageal reflux disease	1	1	2	1
	Nausea	1	1
	Tooth disorder	1	1
	Vomiting	1	1	1	1
Gastrointestinal disorders Total		7	6	4	3
General disorders and administration site conditions	Atrophy	1	1
	Chest discomfort			1	1
	Pain	1	1
	Pyrexia	1	1
General disorders and administration site conditions Total		3	3	1	1
Infections and infestations	Acute sinusitis	1	1	1	1
	Bronchitis	2	2	1	1
	Bronchitis acute			1	1
	Ear infection	1	1
	Fungal infection	1	1
	Gastritis viral	1	1	1	1
	Gastroenteritis viral			2	2
	Herpes simplex	1	1
	Influenza			1	1
	Nasopharyngitis	1	1	2	2
	Otitis media	2	1
	Pneumonia	1	1
	Sinusitis	8	5	4	3
	Upper respiratory tract infection	3	3	1	1
	Urinary tract infection	1	1	1	1
	Vaginal candidiasis	1	1
	Varicella			1	1
	Viral upper respiratory tract infection	5	3
	Vulvovaginal mycotic infection			1	1
Infections and infestations Total		29	12	17	10
Injury, poisoning and procedural complications	Contusion			1	1
	Excoriation	1	1
	Joint injury	1	1
	Limb injury	2	2
	Skin laceration	2	1	2	1
	Thermal burn			1	1
	Wound	1	1
Injury, poisoning and procedural complications Total		7	3	4	1
Investigations	Antibody test abnormal	2	1
Investigations Total		2	1
Metabolism and nutrition disorders	Vitamin B12 deficiency			1	1
Metabolism and nutrition disorders Total				1	1
Musculoskeletal and connective tissue disorders	Back pain	2	2
	Musculoskeletal pain	1	1
	Musculoskeletal stiffness	1	1
	Pain in extremity	2	2	1	1
Musculoskeletal and connective tissue disorders Total		6	5	1	1
Nervous system disorders	Carpal tunnel syndrome	1	1
	Dizziness	1	1
	Headache	4	4
Nervous system disorders Total		6	5
Psychiatric disorders	Depression			1	1
Psychiatric disorders Total				1	1
Reproductive system and breast disorders	Vulvovaginal discomfort	1	1
Reproductive system and breast disorders Total		1	1
Respiratory, thoracic and mediastinal disorders	Cough	1	1	1	1
	Laryngeal oedema	1	1
	Nasal congestion			1	1
	Pharyngolaryngeal pain			1	1
	Postnasal drip	1	1
	Rhinorrhoea			1	1
	Sinus congestion	1	1
Respiratory, thoracic and mediastinal disorders Total		4	4	4	3
Skin and subcutaneous tissue disorders	Dermatitis contact			1	1
	Erythema	1	1