A double-blind, randomized, controlled study of oral pirfenidone for treatment of secondary progressive multiple sclerosis

A double-blind, randomized, controlled study of oral pirfenidone fortreatment of secondary progressive multiple sclerosis

Jonathan E Walker*,1, Shri N Giri2 and Solomon B Margolin2

1Board Certified Psychiatry and Neurology, 12870 Hillcrest, Suite #201, Dallas, TX 75230, USA; 2Marnac, Inc., 9400 N.Central Expressway, Suite #305, Dallas, TX 75231, USA

Currently, there are no approved treatments for secondary progressive multiple sclerosis (MS) that stabilize or reverse the neurologicaldisabilities associated with this disease. Oral pirfenidone was found to stabilize and overcome the disabilities in two published independentopen-label studies in secondary progressive MS. This led us to study pirfenidone in a phase II double-blind, randomized and controlled,clinical trial in patients with advanced secondary progressive MS for 12 months. Forty-three patients met the eligibility criteria approvedby the IRB and accepted by the FDA. Of these patients, 18 were randomly assigned to placebo and 25 patients to oral pirfenidone groups.All eligible patients were included in the statistical analysis of the data according to intention-to-treat principles. Some patients on oralpirfenidone manifested mild drug-related adverse effects, but it was well tolerated overall. By one month, pirfenidone significantly ( PB/

0.05) improved the Scripps Neurological Rating Scale (SNRS) scores, and scores remained significantly improved for 3, 6 and 12 monthswhen compared to the baseline SNRS scores. In contrast, the SNRS scores of patients on oral placebo were not significantly improved at1, 3, 6 or 12 months of the study, when compared with baseline scores. Oral pirfenidone significantly ( PB/0.04) reduced the incidence ofrelapses (27.8% on placebo versus 8.0% on pirfenidone). Furthermore, oral pirfenidone treatment was associated with a markedimprovement in bladder dysfunction (40.0% on pirfenidone versus 16.7% on placebo). Expanded Disability Status Scale scores and MRIlesion count were not significantly different in the placebo and pirfenidone groups. These findings indicate a significant effect of pirfenidoneon clinical disability and bladder function for secondary progressive MS patients. A major multicentre, double-blind, randomized,controlled trial is justified.Multiple Sclerosis (2005) 11, 149�/158

Key words: multiple sclerosis; pirfenidone; TNF-alpha; treatment

Introduction

Multiple sclerosis (MS) is a demyelinating disorder that

is characterized by neurological deficits attributable to

demyelinating lesions and progressive axonal loss in the

white matter. It is one of the most common central nervous

system disorders, with prevalence of 250 000�/350 000

persons in the USA.1 The clinical signs of MS may appear

at any age, although the onset of this neurological disorder

in childhood or after age 50 is rare. The incidence of MS in

females is twice that in males. Although the underlying

pathogenic mechanisms of MS are poorly understood,

environmental, genetic and immune factors have been

implicated.2�4

The immunological factors responsible for destruction

of the myelin sheath have been the focus of much

investigation. In this regard, there is a great deal of

evidence for the involvement of TNF-alpha in the demye-

lination and consequently in the progressive pathogenesis

of MS5�9 for a number of reasons. First, it has been

demonstrated in vitro that TNF-alpha is cytotoxic for

murine and rat oligodendrocytes, the myelin-producing

cells in the CNS,10 and there is a strong association

between TNF-alpha level in cerebrospinal fluid (CSF)

and disease progression in patients with MS.11 Secondly,

both TNF-alpha and interferon-gamma are able to induce

expression of intercellular adhesion molecule-1 (ICAM-1)

on human brain endothelial cells12 and on both oligoden-

drocytes and astrocytes in vitro.13 There is also evidence

that TNF-alpha is able to induce expression of vascular

cell adhesion molecule-1 (VCAM-1) on spinal cord en-

dothelium in animals suffering from experimental allergic

encephalomyelitis (an animal model of MS).14 Upregula-

tion of ICAM-1 and VCAM-1 on brain endothelium has

been demonstrated in MS plaques15 and is probably a

prerequisite for entry of inflammatory cells in the CNS

parenchyma. Increased levels of ICAM-1 and TNF-alpha

in serum and CSF of MS patients have been found to

correlate with disease activity.16 In addition, proinflam-

matory cytokines such as TNF-alpha, IL-1 and interferon-

gamma induce the synthesis of nitric oxide17,18 with broad

proinflammatory activity. There is a strong expression of

inducible nitric oxide synthase activity in macrophages in

regions of active demyelination in MS lesions.19

The evidence that TNF-alpha plays a pivotal role in the

pathogenesis of MS led us to investigate the effects of

pirfenidone, a known inhibitor of TNF-alpha synthesis

*Correspondence: Jonathan E Walker, 12870 Hillcrest,Suite #201, Dallas, TX 75230, USA.E-mail: [email protected] 14 April 2004; revised 23 September 2004;accepted 29 September 2004

Multiple Sclerosis 2005; 11: 149�/158www.multiplesclerosisjournal.com

# 2005 Edward Arnold (Publishers) Ltd 10.1191/1352458505ms1134oa

and its pharmacological and toxicological actions,20 �22 in

two independent open trials in secondary progressive MS

patients.23,24 Encouraged with the favourable outcome of

these two open trials, we tested in the present study the

efficacy of pirfenidone in a phase II double-blind, rando-

mized study in patients with advanced secondary pro-

gressive MS.

Methods

Study designThe protocol for a randomized double-blind controlled

study in advanced secondary progressive MS that was

approved by an institutional review board and accepted

by the FDA was followed in this trial study. Each patient

enrolled in the study signed an approved informed

consent form that was properly countersigned by a

qualified witness.Forty-three patients with severe secondary progressive

MS were initially enrolled in the study. Patients were

evaluated for neurological dysfunction and had brain MRI

scans just before being enrolled and subsequently at six

and 12 months.

Patient selection Forty-three patients with a diagnosis of

advanced secondary progressive MS25 were recruited for

this double-blind study from a single neurology practice.

The demographic and baseline clinical characteristics of

patients randomly assigned to placebo and pirfenidone

groups are shown in Table 1. Patients had relapsing and

remitting MS for varying lengths of time since the first

neurological diagnosis (Table 1). At baseline, none of the

patients were immunosuppressed as evaluated by total

WBC counts, WBC differential counts or lymphocyte

counts.The neurologist had closely followed all patients before

being admitted to the study and these patients had

experienced definite progressive worsening symptoms

for two years or longer. The enrolled patient population

was drawn from an ongoing neurology practice and this

setting reflected a traditional neurology specialty practice.

Inclusion criteria Included: 1) clinically definite or la-

boratory-supported advanced secondary MS, using the

Poser criteria;25 2) presence of secondary progressive

disease (patients must have worsened by at least one

EDSS unit in the last two years); 3) patients must not have

had an exacerbation during the 30 days prior to enrolment;

4) presence of progressive component of the disease for at

least two years; 5) presence of modified Expanded

Disability Status Scale (EDSS) scores between 5 and 8; 6)

agreement to use adequate contraception during the study

for fertile female patients; and 7) patients must be able to

understand and sign an informed consent form.

Exclusion Patients were excluded from the study based

on the following criteria: 1) unlikely to complete the

scheduled follow-up visits; 2) treated with immunosup-

pressive drugs within the past 90 days; 3) pregnancy or

breast feeding; 4) severe medical illness of any kind; and

4) inability to undergo an MRI scan.After completion of screening evaluations, 43 qualifying

patients were enrolled. The procedure for randomization

and blinding were as follows. Dr Walker’s assistant first

informed Marnac, Inc., the sponsor of the study, of a new

patient to be enrolled and randomized into the study. At

that time, the representative of the sponsor would assign

the next sequential patient number using a Random

Digital Table26 to the patient along with the patient’s

initials to drug A (pirfenidone arm) or drug B (placebo

arm) predetermined by the randomization table. The

medication starter package would then be labelled with

the number and patient’s initials according to the rando-

mization table and delivered only to Dr Walker who

acknowledged receiving the package by his signature on

an official form developed by the sponsor of the study.The effectiveness of the blinding was maintained by

strictly adhering to the following guidelines: 1) the bottles

containing the capsules were delivered only to Dr Walker,

and they were coded and could not be identified as to

whether they contained placebo or pirfenidone capsules;

2) the code was never in the possession of Dr Walker

and his staff as it was kept under security lock and key

at the Central Management Regulatory administration

office; 3) Dr Walker had no way of knowing who was

on placebo and who was on pirfenidone; 4) Dr Walker and

Table 1 Demographic and baseline clinical characteristics of the placebo versus pirfenidone groups

Baseline characteristics Placebo Pirfenidone

Female Male Female Male

Number of patients 14 4 18 7Age 49.29/1.79* 58.39/5.33** 45.99/2.49 52.39/4.40MS first symptoms (years ago) 13.39/3.74 16.89/6.76 11.79/1.78 13.49/2.40EDSS scores (unit) 6.119/0.19 6.39/0.48 6.149/0.14 6.439/0.34SNRS scores 66.99/3.6 70.59/4.17 62.49/2.67 54.19/4.52

Each value represents mean9/SEM.

*No significant difference (P �/0.05) between females in placebo and females in pirfenidone groups for any matching characteristics

(Student’s t -test).

**No significant difference (P �/0.05) between males in placebo and males in pirfenidone groups for any matching characteristics

(Student’s t -test).

Oral pirfenidone in secondary progressive multiple sclerosisJE Walker et al.

150

Multiple Sclerosis

a radiologist interpreted the MRIs independently; and5) Dr Walker did not know the name of the patients in theprocess of interpreting MRIs as the name of the patientswere blocked by opaque tape. The representative ofthe sponsor had access to the blinding code around theclock in case of an emergency for unblinding purposes.Dr Walker, the investigator of the study, and the patientsremained blinded throughout the entire period of the trial.These steps maintained the effectiveness of the blinding

procedure even though Dr Walker was responsible forevaluating the clinical status of the patients.

Schedule of observation The clinical visits for the historyand physical and neurological examinations of the pa-tients occurred at the baseline, and then at 1, 3, 6, 9 and 12months. The parameters for neurological evaluationsincluded: Scripps Neurological Rating Scale (SNRS)according to Sipe et al .27 and EDSS according to themodified criteria from Kurtzke.28 The MRI scan was doneat baseline, six and 12 months according to the procedure

described in our earlier papers.23,24 The numbers of newor enhancing lesions were determined by comparing MRIscans at six and 12 months with the baseline scans. Theradiologist and Dr Walker, the investigator of the study,were blinded to the group (placebo versus pirfenidone)and evaluated the MRIs independently.

Laboratory blood tests The blood tests including CBCand SMAC-20 (sodium, potassium, chloride, glucose,BUN, creatinine, calcium, phosphate, total protein, albu-min, bilirubin, AST, alkaline phosphatase) were per-

formed at baseline, six and 12 months after beginningtreatment.

Relapse A clinical relapse was defined as the appear-ance of new symptoms or worsening of an old existingsymptom, attributable to MS and accompanied by objec-tive worsening of neurological findings (SNRS). To bescored as a relapse, the alterations must have been severeas determined by an increase from baseline at least onepoint on two functional system scores or at least twopoints on one functional system score, and preceded by an

interval of disease stability or improvement. The worsen-ing must have lasted for at least 24 hours in the absence offever, and must have required short-term medicationswith oral prednisone.

Study medications The study medications were providedby Marnac, Inc., (Dallas, TX), the sponsor of the trial, ina form suitable for oral administration as follows:1) pirfenidone pure powder 400 mg without excipientswas encapsulated in a hard gel capsule; 2) placebocapsules containing inert white powder were also encap-

sulated in matching hard gel capsules. There were 50capsules in each dispensing bottle. The capsules contain-ing pirfenidone or placebo were prepared in compliancewith the FDA-approved Good Manufacturing Practices atthe Department of Veteran’s Affairs Cooperative StudiesProgram, School of Pharmacy, University of New MexicoHealth Sciences Center, Albuquerque, NM.

Dose regimen for administration Patients were initiallytitrated for each capsule preparation up to a maintenancedose over a period of 10�/14 days to assure adequatetolerance to oral drugs during the trial. During this period,each patient started with one capsule twice daily for twodays, increased to one capsule three times daily for twodays, four capsules daily for two days (one in the morning,one at noon and two in the evening), five capsules dailyfor two to four days (two capsules in the morning, onecapsule at noon, two capsules in the evening) followed upwith two capsules three times a day for a maximum of sixcapsules.

Patients were instructed to take capsules during mealsor with other food and swallow with a full glass of wateror other nonalcoholic beverage. An antacid, such as Tums,was given to counteract any gastric discomfort. A fewpatients dissolved the content of the capsule into a glass oforange juice and then swallowed. This measure was takento minimize the gastric discomfort of the capsules. Anydrowsiness was minimized with caffeine beverage, if itoccurred.

All patients had been off all disease-modifying therapy,including corticosteroids, for at least three months. Con-comitant medications known to induce skin rash wereavoided. The administration of any concomitant drugswas promptly recorded in the appropriate section of theCase Report Forms. All blinded coded pirfenidone andplacebo capsules were delivered only to Dr Jonathan E.Walker, the principal clinical investigator of the study, andhis signature was required to confirm all drug deliveries.

Endpoints and plan of treatment The enrolled patients atthe onset were studied in order to acquire the baselinedata for their documented degree of progression of thedisease and neurological status, CBC, differential, urineanalysis and an MRI of the brain. The neurologicalevaluation included: 1) vital signs (blood pressure, pulseand respiration rate); 2) classical neurological examina-tion; 3) SNRS score; and 4) EDSS score.

Evaluation and statistical considerations

The primary outcome This was based on inhibition of theprogression of disease as assessed by the SNRS scores atbaseline, one, three, six and 12 months. The secondaryoutcomes included: 1) incidence of relapse; 2) urinarybladder dysfunction; 3) EDSS scores; and 4) number ofnew and gadolinium-enhancing lesions on MRI brainscans at baseline, six and 12 months.

The safety profile This included pre-drug baseline his-tory and physical examinations followed by regularlyscheduled (baseline, six and 12 months) blood chemis-tries, blood cell counts and urine analyses.

The methods employed for testing the data for statisticalsignificance were approved by the IRB and accepted bythe FDA. All eligible patients who were enrolled in thetrial were included in the analysis of the data as mandatedby the intention-to-treat principles.29 The data for patientsin placebo and pirfenidone-treated groups are presented


151

Multiple Sclerosis

as mean9/SEM. The SNRS scores at one, three, six and 12months for each group were compared with the baselinedata of the same group. Repeated Measures of ANOVAfollowed by Newman�/Keuls Multiple Comparison Testwas performed to analyse the statistical significance of theSNRS scores among the four groups of each arm of thestudy using SigmaStat for Windows Version 1, JandelScientific Corporation (San Rafel, CA). The differences inranks in the changed SNRS scores from the baseline dataof the individual patients between the pirfenidone andplacebo groups at one, three, six and 12 months were alsoanalysed for statistical significance using the Mann�/

Whitney Two-Sample Rank Test according to the proce-dure described by Zar.30 In addition, Student’s t -test andchi-square as appropriate were used for statistical analysisof data. A value of P B/0.05 was considered to be theminimum level for statistical significance.

Results

Reasons for drop outOut of the initial 43 patients with secondary progressiveMS who met the inclusion criteria, 18 were assigned atrandom to the placebo and 25 to the pirfenidone groups.The demographic and baseline clinical characteristicsof patients in placebo and pirfenidone groups are sum-marized in Table 1. There was no significant difference(P �/0.05) in any clinical parameter in females or malesbetween the placebo and pirfenidone groups. This pro-vides evidence that patients in placebo and pirfenidonegroups were well matched on all clinical parameters priorto starting treatment.

In the placebo group, seven patients dropped out of thestudy (39%), whereas in the pirfenidone group, ninepatients dropped out (36%). The time of drop out forpatients in the placebo group averaged 6.149/0.96 monthswith a range of one to nine months, whereas in thepirfenidone group, the average was 4.229/0.86 monthswith a range of one to eight months. There was nosignificant difference in the time of drop out betweenthe two groups. Seven patients dropped out only as aresult of continual marked progression of disease in theplacebo group. Other reasons for drop out in the placebogroup included supraventricular tachycardia (1), hepatitis(1) and colon surgery (1). In the pirfenidone group, thereasons for drop out (unrelated to drug therapy) includedcongestive heart failure (1), discontinuation of treatmentwithout notification (1), patient’s request to withdrawfrom the trial because of travelling distance (1), lack ofimprovement (1), generalized weakness (1) and progres-sion of disease in (1) patient. Three patients dropped outfrom the trial in the pirfenidone group due to drug-relatedadverse effects: nausea (1), weight loss and anorexia (1)and skin rash (1).

Laboratory testThe laboratory blood test results for electrolytes anddifferential white cell counts and urine analyses for both

groups were normal at baseline and at all subsequentintervals during the trial period.

Scripps Neurological Rating Scale

There was no statistically significant (P �/0.05) differencein mean SNRS score between the placebo and pirfenidonegroups when patients were initially assigned at random totheir respective arms of the study (Table 1). The improve-ment in the SNRS scores of all enrolled patients in theplacebo and pirfenidone groups at one, three, six and 12months was compared with their respective mean baselineSNRS scores according to the intention-to-treat principles.

The mean SNRS scores at one, three, six and 12 monthswere not significantly different (P �/0.05) from the base-line score of the patients on placebo (Table 2). Thisprobably indicates a mild placebo effect on SNRS scoresfor these patients. However, the patients taking pirfeni-done had significant (P B/0.05) increases (RMANOVA) inthe mean SNRS scores at one, three, six and 12 months ascompared to the mean baseline score of this group (Table2). The increases in the SNRS score indicate the effective-ness of pirfenidone therapy in reducing neurologicaldysfunction of patients suffering from advanced second-ary progressive MS. This effect was noted from one monthonward.

The changes in SNRS scores from the baseline scoresof individual patients in the pirfenidone and placebogroups at one month are summarized in Figure 1. Thechanged scores ranged from �/8 to �/22 units in patientson oral pirfenidone, whereas the changed scores inpatients on oral placebo ranged from �/5 to �/9 units.The Mann�/Whitney Two-Sample Rank Test revealedthat the rank in changed SNRS scores was significantly(P B/0.05) higher in patients on oral pirfenidone than thepatients on placebo.

The changes in SNRS scores from the baseline scoresof individual patients in pirfenidone and placebo groupsat three months are summarized in Figure 2. The changedSNRS scores ranged from �/8 to �/29 units in patientson oral pirfenidone, whereas the changed scores inpatients on oral placebo ranged from �/9 to �/14 unitsat this time. The rank in changed SNRS scores wassignificantly (P B/0.05) higher in the patients on oralpirfenidone than the patients on oral placebo accordingto the Mann�/Whitney Two-Sample Rank Test.

Table 2 Scripps scores at baseline one, three, six and 12 months in

secondary progressive MS patients on oral placebo or pirfenidone

Months Placebo (n�/18),mean scores/units

Pirfenidone (n�/25),mean scores/units

Baseline 67.79/2.89 60.29/2.371 69.09/2.62 NS 65.59/2.30*3 71.69/3.07 NS 68.19/2.38*6 71.29/3.44 NS 69.19/2.80*

12 71.29/3.62 NS 68.39/2.75*

Each value represents mean9/SEM.

*Improvement in values is statistically significant (P B/0.05) from

baseline (RM ANOVA).

NS�/not significant.


152

Multiple Sclerosis

The changes in SNRS scores from the baseline scoresof individual patients in pirfenidone and placebo groupsat six months are summarized in Figure 3. The changedSNRS scores in patients on oral pirfenidone ranged from�/13 to �/39 units, whereas the changed SNRS scores

in patients on oral placebo ranged from �/25 to �/19 units.The rank in changed SNRS scores was significantly(P B/0.05) higher in the patients on oral pirfenidone thanthe patients on oral placebo according to the Mann�/

Whitney Two-Sample Rank Test.The changes in SNRS scores from the baseline scores

of individual patients in pirfenidone and placebo groupsat 12 months are summarized in Figure 4. The changedSNRS scores in patients on oral pirfenidone ranged from�/13 to �/37 units, whereas the changed SNRS scoresin patients on oral placebo ranged from �/25 to �/19 units.The rank in changed SNRS scores was significantly(P B/0.05) higher in the patients on oral pirfenidonethan the patients on oral placebo according to theMann�/Whitney Two-Sample Rank Test.

RelapsesDuring the 12 months of the trial, 5/18 patients (27.8%)with advanced secondary progressive MS experiencedrelapses in the placebo group as compared to 2/25 patients(8.0%) in the pirfenidone group (Table 3). The relapseswere controlled by oral prednisone (100mg/daily) forseven days. The oral pirfenidone significantly (P B/0.04)suppressed the occurrence of relapses in the secondaryprogressive MS patients over the placebo.

Urinary bladder dysfunction

The effects of oral placebo or pirfenidone on urinarybladder dysfunction of patients with secondary progres-sive MS are summarized in Table 4. The bladder function

Pirfenidone1 Month

11

-8

0 03

11

3

13

6 4

22

0 0 1

-1

1012

4 3 3 50

12 10 9

-30

-20

-10

0

10

20

30

40

5 6 7 9 11 13 14 15 16 18 19 25 26 27 29 31 32 33 35 36 39 40 41 42 43

Patient Number

Ch

ang

es in

Scr

ipp

s S

core

Placebo1 Month

4

-4

0

-1

0 04

-3

0

7

-5 -4

4 2 38 9

0

-30

-20

-10

0

10

20

30

40

1 2 3 4 7 10 12 17 20 21 22 23 24 28 30 34 37 38

Patient Number

Ch

ang

es in

Scr

ipp

s S

core

s

Figure 1 Changes in SNRS scores from the baseline of the

individual patients on oral pirfenidone or placebo at one month.Rank in changed SNRS scores of patients in pirfenidone group

was significantly (PB/0.05) higher than patients on oral placebo

(Mann�/Whitney Two-Sample Rank Test).

Pirfenidone3 Month

11

-5-8

0 0

14

4

159

4

29

0

8

0

-1

21

127 7 7

1115

1216

9

-30

-20

-10

0

10

20

30

40

5 6 7 9 11 13 14 15 16 18 19 25 26 27 29 31 32 33 35 36 39 40 41 42 43

Patient Number

Ch

ang

es in

Scr

ipp

s S

core

Placebo3 Month

6 71

-9

60

8

-5

47

30

9

2 3

14 14

0

-30

-20

-10

0

10

20

30

40

1 2 3 4 7 10 12 17 20 21 22 23 24 28 30 34 37 38

Patient Number

Ch

ang

es in

Scr

ipp

s S

core

s


individual patients on oral pirfenidone or placebo at threemonths. Rank in changed SNRS scores of patients in pirfenidone

group was significantly (PB/0.05) higher than patients on oral

placebo (Mann�/Whitney Two-Sample Rank Test).

Pirfenidone6 Month

11

-3-8

0

9

16

2

17

94

39

0

13

-13-4

21

129

127 5

16

23

16

9

-30

-20

-10

0

10

20

30

40

5 6 7 9 11 13 14 15 16 18 19 25 26 27 29 31 32 33 35 36 39 40 41 42 43

Patient Number

Ch

ang

es in

Scr

ipp

s S

core

Placebo6 Month

6 8 8

-25

10

0

9

-5

6 71

-4

10

-2

3

12

19

0

-30

-20

-10

0

10

20

30

40

1 2 3 4 7 10 12 17 20 21 22 23 24 28 30 34 37 38

Patient Number

Ch

ang

es in

Scr

ipp

s S

core

s


individual patients on oral pirfenidone or placebo at six months.

Rank in changed SNRS scores of patients in pirfenidone group

was significantly (PB/0.05) higher than patients on oral placebo(Mann�/Whitney Two-Sample Rank Test).


153

Multiple Sclerosis

in four (4/18) patients (22.2%) on placebo underwent

deterioration during the trial period. For example, two

patients who had normal bladder function at the baseline

developed a moderate degree of bladder dysfunction in

one month and remained that way for the duration of the

study, whereas a moderate degree of bladder dysfunction

in two patients at baseline progressed into severe dysfunc-

tion in six months and continued at that level for the

entire 12 months of the trial. In contrast, none of

the patients (0/25) on oral pirfenidone experienced any

further deterioration of bladder function from the base-

line. The absence of any further deterioration in urinary

bladder function in patients on oral pirfenidone was in

marked contrast to patients on placebo who developed

significant (P B/0.007) deterioration during the trial

period. The bladder function in patients on placebo was

improved in 16.7% patients (3/18) who had severe

dysfunction at the baseline in contrast to an improvementin 40% patients (10/25) in the pirfenidone group withinsix months followed by restoration of normal bladderfunction during the trial period. Thus, patients withsecondary progressive MS on oral pirfenidone showeda significant (P B/0.05) improvement in urinary bladderdysfunction as compared to the patients on placebo(Table 4).

EDSS scoresThe EDSS scores of patients suffering from secondaryprogressive MS on placebo or pirfenidone are summarizedin Table 5. Patients on placebo trended to deteriorate,while patients on pirfenidone appeared to stabilize. Thedifference was not statistically significant however.

MRI evaluationsThe MRI evaluations of secondary progressive MS patientson placebo and pirfenidone were carried out prior tostarting treatment (baseline) and at six and 12 months oftreatment. Total number of lesions present in the whitematter, periventricular and subcortical white matter werequantified using MRI scan. Also quantified were enhan-cing lesions in these areas. There were no statisticalsignificant differences in the number of lesions amongthe baseline, six and 12 months either in placebo orpirfenidone group as analysed by RMANOVA (data notshown). Similarly, there were no statistically significantdifferences in the baselines, six or 12 months betweenplacebo and pirfenidone groups when compared at thecorresponding times by unpaired Student’s t -test.

Pirfenidone12 Month

11

-3-8

0

9 9

2

17

94

37

0

12

-13 -4

21

12

0

15

5 6

16

23

129

-30

-20

-10

0

10

20

30

40

5 6 7 9 11 13 14 15 16 18 19 25 26 27 29 31 32 33 35 36 39 40 41 42 43

Patient Number

Cha

nges

in S

crip

ps

Sco

re

Placebo12 Month

69 11

-25

12

0

9

-5

8 71

-6

11

-8

3

12

19

0

-30

-20

-10

0

10

20

30

40

1 2 3 4 7 10 12 17 20 21 22 23 24 28 30 34 37 38

Patient Number

Cha

nge

s in

Scr

ipp

s S

core

s


individual patients on oral pirfenidone or placebo at 12 months.

Rank in changed SNRS scores of patients in pirfenidone group

was significantly (PB/0.05) higher than patients on oral placebo(Mann�/Whitney Two-Sample Rank Test).

Table 3 Incidence of relapse of secondary progressive MS

patients on oral placebo or pirfenidone during 12 months of

clinical trial

Treatment Number ofpatients

Numberexperiencedrelapse

% patientsexperiencedrelapse

Placebo 18 5 27.8Pirfenidone 25 2 8.0*

*Statistically significant lower relapse rate (P B/0.04) by oral

pirfenidone (chi-square test).

Table 4 Effects of oral placebo or pirfenidone on urinary bladder

dysfunction in secondary progressive MS patients

Category Placebo (n�/18) Pirfenidone (n�/25)

Deterioration 4/18*�/22.2% 0/25�/0%Improvement 3/18�/16.7% 10/25**�/40%No effect 11/18�/61.10% 15/25�/60%

*Statistically significant deterioration in bladder function

(P B/0.007) compared to pirfenidone by chi-square test.

**Statistically significant improvement in bladder function

(P B/0.05) over placebo by chi-square test.

Table 5 EDSS scores at baseline one, three, six and 12 months in

secondary progressive MS patients on placebo or pirfenidone

Months EDSS scores* (mean9/SEM)

Placebo (n�/18) Pirfenidone (n�/25)

Baseline 6.149/0.18 6.229/0.141 6.149/0.18 6.229/0.143 6.089/0.20 6.209/0.146 6.089/0.24 6.209/0.14

12 5.979/0.27 6.169/0.16

*There is no significant difference between baseline and any

evaluation time of either placebo or pirfenidone group, though

there was a trend to worsening in the placebo group, whereas the

pirfenidone group trended toward stabilization.


154

Multiple Sclerosis

Discussion

MS is a chronic, autoimmune inflammatory disorder ofthe central nervous system, characterized by a spatial andtemporal dissemination of pathological processes thataffect primarily the white matter in the central nervoussystem and thereby cause both physical and psychologicaldisability. Although the aetiology of MS is not clearlyunderstood, there is abundant evidence of the involve-ment of TNF-alpha in the demyelination that is consid-ered to be a major component in the pathogenesis ofMS.5�9 There is also evidence suggesting the involvementof oxidative stress in the pathogenesis of this disease.31,32

Pirfenidone, 5-methyl-1-phenyl-2-(H) pyridone, is anorally administered small molecule. Its beneficial effectsfor treatment of patients with advanced secondary pro-gressive MS have been reported in two independent openlabel trials23,24 and in the phase II double-blind rando-mized trial reported in the present study. This was shownby finding that patients on oral pirfenidone had signifi-cantly improved SNRS scores at one, three, six and 12months as compared to the baseline score of this group.However, this was not found for patients on placebo astheir SNRS scores at one, three, six and 12 months wereinsignificantly increased from the baseline scores. More-over, the patients on oral pirfenidone had significantlyhigher rank in improved SNRS scores from their indivi-dual baseline scores than the patients on placebo at allcorresponding times as indicated by the Mann�/WhitneyTwo-Sample Rank Test.

The second line of evidence for beneficial effects ofpirfenidone in secondary progressive MS was reflected bythe fact that only one patient in this group dropped outfrom the trial in contrast to seven patients in the placebogroup who dropped out as a consequence of the progres-sive worsening of their disease. The third line of evidencewas provided by a dramatic improvement in urinarybladder function of several patients in the pirfenidonegroup. Patients with MS have frequent problems withurinary bladder dysfunction (urgency, frequency and urgeincontinence due to bladder overactivity and/or incom-plete emptying) and the same type of dysfunction is foundin 75% of patients.33 There was a lack (0.0%) of anyfurther deterioration in the bladder function and a markedimprovement in the bladder function in 40% patients onoral pirfenidone as compared to 16.7% improvement and22.2% deterioration in the bladder function in patients onoral placebo during the trial period. Fourth, a significantreduction occurred in the number of patients experiencingrelapses on oral pirfenidone. For instance, 27.8% patientswith secondary progressive MS experienced relapseswhile on oral placebo as compared to only 8.0% patientson oral pirfenidone during the trial period.

EDSS scores of secondary progressive MS patientstrended to stabilize on pirfenidone whereas this indextrended to deteriorate in patients on placebo from thebaseline at one, three, six and 12 months. However, thedifference was not significant between the two groups.There were no significant differences in total MRI lesionsbetween the pirfenidone and placebo groups when

compared either at the corresponding time intervals or at

any time of evaluation to the baseline of each arm of the

study. It is not uncommon to find a discrepancy between

the clinical observations and some indexes used to

monitor the progression of MS. For instance, a reduction

in relapses without significant differences in the EDSS

score or in the development of active MRI lesions has been

reported in a controlled study.34 Although MRI is fre-

quently applied for diagnostic purposes, T2-weighted

lesions lack histopathologic specificity and thus measures

of T2 lesion load correlate poorly with the degree of

clinical disability.35,36 In fact, the use of MRI as a surrogate

outcome measure was examined by an international group

of investigators with expertise in clinical aspect of MS and

experimental therapeutics. The group agreed that MRI

does not represent a validated surrogate in any clinical

form of MS and clinical trials using MRI as a primary

outcome measure may fail to fully identify the effects of

therapy on clinical measures.37,38

The axonal injury in response to an excess production

of TNF-alpha by activated oligodendrocytes, macrophages

and microglia occurs in the pathogenic process of MS5�9

as well as in other degenerative and inflammatory diseases

of the neurons.39,40 As an excess production of TNF-alpha

plays a pivotal role in the pathogenesis of MS, any

therapeutic strategies that target TNF-alpha may have

potentially therapeutic benefits for management of MS.

Previous studies to treat MS with TNF-alpha neutralizing

antibody and TNF-receptor-blocking agents may have

failed because of their relatively poor ability to decrease

TNF-alpha synthesis, weaker blockade of TNF-alpha

receptors and/or poor accessibility to the CNS.41,42

The beneficial effects of pirfenidone in secondary

progressive MS patients as reported in this double-blind,

randomized, controlled study may primarily be due to its

ability to minimize the demyelination by inhibiting the

production and/or action of TNF-alpha as demonstrated

by several investigators both in vitro and in vivo.20�22 It is

probable that pirfenidone not only inhibits the production

and action of TNF-alpha in peripheral organs but also in

the central nervous system as well, as it is uniformly

distributed in body water and crosses the blood�/brain

barrier easily.43 Based on the finding of the authors of the

current paper that pirfenidone markedly inhibited the

porcine myeloperoxidase (pMPO)-induced increased pro-

duction of TNF-alpha by astrocyte cells of human origin

(unpublished), it is conceivable that pirfenidone may also

reduce the TNF-alpha-induced pathological proliferation

of astrocytes and help re-establish normal astrocyte

support of neurons and neuronal transmission.2,22,44

Other TNF-alpha-based therapies for MS were proven to

be not efficacious because they were weak inhibitors of

TNF-alpha synthesis and TNF-alpha receptor blockers.

However, besides well documented anti-TNF-alpha ac-

tion, by strongly inhibiting TNF-alpha synthesis and

blocking TNF-alpha receptors, pirfenidone has other

pharmacological effects, which could provide added

beneficial effects against secondary progressive MS. These

include: a) ability of pirfenidone to scavenge reactive

oxygen species (ROS)45,46 responsible for the oxidative


155

Multiple Sclerosis

stress implicated in the pathogenesis of MS;31,32 b) ability

of pirfenidone to block the production of other proin-

flammatory cytokines21,47 secreted by the dendritic cells

in patient with MS;48 c) ability of pirfenidone to attenuate

inflammation49 involved in the pathogenesis of MS;50 d)

ability of pirfenidone to block the production of inter-

cellular adhesion molecues51 implicated in the MS

disease activity;15,16 and ability of pirfenidone to block

the synthesis of nitric oxide47 implicated in pathogenesis

of MS.19

Transcriptional activation of specific inflammatory

cytokine genes such as IL-1alpha, IL-6, IL-8 and TNF-

alpha is mediated by NF-kB activation in various cell

types under a wide range of conditions.52 Binding sites for

the NF-kB family of transcription factors are found in the

promoter and enhancer regions of a multitude of genes

including cytokines, chemokines and growth factors that

are involved in the inflammatory response. It has been

shown that activation and translocation of NF-kB from

cytoplasm into nucleus where it binds to DNA occurred invitro53 and in vivo54 in response to elevated levels of ROS

prior to transcriptional activation of inflammatory cyto-

kine genes and their gene products including TNF-alpha

in these studies. As NF-kB is an oxidant-sensitive tran-

scription factor,55 it is not surprising that bleomycin56,57

(generator of ROS)-induced activation of this transcription

factor was blocked by pirfenidone,58 a known scavenger

of ROS.45,46 This resulted in downregulation of the

expression of the inflammatory cytokine genes including

TNF-alpha and IL-1 genes and subsequently the produc-

tion of TNF-alpha and IL-1 as demonstrated recently

in vivo.47 Thus the blockade of activation of NF-kB by

pirfenidone in the CNS may conceivably be one of the

mechanisms for the inhibitory effects of pirfenidone on

synthesis of proinflammatory cytokines, ICAM-1 and NO

and this would arrest the ongoing inflammation and

demyelination which play a major role in the pathogenesis

of secondary progressive MS.The FDA has approved four disease-modifying thera-

pies for patients with relapsing�/remitting MS: interferon

beta-1b,59 two interferon beta-1a products60 and glatiramer

acetate.61 These drugs reduce the rate of clinical relapses

and progression of the disease by modulating the immune

system. Although interferon beta-1b has been approved for

use in secondary progressive MS in Europe and Canada, in

two recently completed phase III trials, it was found that

treatment with interferon-1b did not slow the progression

of disability.62,63 It does not always slow the progression

of axonal injury in MS.64

The FDA has recently approved mitoxantrone, a cancer

chemotherapeutic agent, for intravenous treatment of

patients with secondary progressive MS.65 However,

17.8% of the patients on mitoxantrone therapy had a

significant decline in left ventricular ejection fraction,

an index of mitoxantrone-induced cardiac toxicity as

revealed in a recent clinical trial.66 In fact, it was

suggested by the authors of this paper that ‘more stringent

cardiac monitoring guidelines than current Food and Drug

Administration (FDA) recommendations be used to

avert potential cardiac complications in SPMS patients

on Mitoxantrone.’ Pirfenidone has much less toxicityand risk than mitoxantrone and is orally effective andaffordable.

Although the encouraging results of this double-blind,randomized controlled study are based on a relativelysmall number of patients (43) with advanced secondaryprogressive MS, it is similar to the study reported bySipe et al.67 in evaluating the effect of cladribine intreatment of a small number of patients (48) with chronicprogressive MS. The beneficial effects of pirfenidonein two independent open label studies in advancedsecondary progressive MS patients, along with thisdouble-blind study, provide convincing evidence for anoteworthy beneficial effect of pirfenidone for the treat-ment of patients with advanced secondary progressiveMS. A larger multicentre, double-blind, randomized,controlled study could substantiate this beneficial effectin treatment of this debilitating disease.

AcknowledgementsThe oral pirfenidone and placebo capsules were providedby Marnac, Inc., Dallas, Texas. In addition, Marnac, Inc.provided the financial support to conduct this clinicaltrial. Dr Nancy A Cox, M.D., Ph.D., Medical Director andMs Judy A Lexvold, Director of Regulatory Affairs ofMarnac, Inc., assisted in the design and monitoring of thestudy. The authors are thankful to Mr Robert H Lexvold,Executive Vice President of Marnac, Inc., for reviewingand Ms Marcy L Raykowski for typing the manuscript.

Disclosure

Dr Jonathan E Walker, M.D., the investigator of this study,has been a paid consultant of Marnac, Inc. for a number ofyears. He does not hold stock or other equity in thecompany.

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A double-blind, randomized, controlled study of oral pirfenidone for treatment of secondary progressive multiple sclerosis

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