close

Вход

Забыли?

вход по аккаунту

?

Antibody-mediated suppression of V5.25.3+ T cells in multiple sclerosis Results from an MRI-monitored phase II clinical trial

код для вставкиСкачать
Antibody-Mediated Suppression of V␤5.2/
5.3⫹ T Cells in Multiple Sclerosis: Results
from an MRI-Monitored Phase II
Clinical Trial
Joep Killestein, MD,1 Tomas Olsson, MD, PhD,4 Erik Wallström, MD, PhD,4
Anders Svenningsson, MD, PhD,4 Mohsen Khademi, MD, PhD,4 Lance D. Blumhardt MD, FRCP,9
Jan Fagius, MD, PhD,5 Jan Hillert, MD, PhD,6 Anne-Marie Landtblom, MD, PhD,7
Charlotte Edenius, MD, PhD,8 Leopold Årfors, MD, PhD,8 Frederik Barkhof, MD, PhD,2,3
and Chris H. Polman, MD, PhD1
The objective of this study was to evaluate the safety and efficacy of the humanized antibody ATM-027 in a baseline
versus treatment magnetic resonance imaging-monitored study. Expansion of V␤5.2/5.3ⴙ T cells has been demonstrated
in the peripheral blood, cerebrospinal fluid, and brain lesions of MS patients. In a phase I study, ATM-027 depleted
these cells in peripheral blood and, in parallel, T-cell MBP reactivity and IFN-␥ expression were reduced. We studied 59
patients with relapsing-remitting MS (47 on ATM-027 and 12 on placebo) stratified for HLA-DR2 status. Monthly
intravenous injections were given for 6 months. Individual dose titration was employed to obtain depletion of the target
T-cell level and downregulation of antigen receptor density as monitored by flow cytometry. Five monthly magnetic
resonance imaging scans were performed before treatment to establish baseline activity, six during treatment, and three
during follow-up. Additional immunological assessments were performed to elucidate the mechanism of action of ATM027. The treatment was safe and well tolerated, inducing consistent suppression of the target cell population. During
run-in, active lesions were found in 78.7% (37/47) of patients treated with ATM-027. During treatment, the median
number of lesions was reduced by 33% (p ⴝ 0.13) independent of DR2 status. The corresponding volume of enhancement was 221 mm3 at baseline, with a reduction of 10% during treatment. Decreased numbers of cells expressing
interferon-␥ messenger RNA, and decreased T-cell reactivity to several myelin antigens were found in ATM-027 treated
patients. In conclusion, consistent suppression of V␤ 5.2/5.3ⴙ T cells was achieved. However, the effect size on magnetic
resonance imaging was considerably less than the targeted 60%.
Ann Neurol 2002;51:467– 474
Multiple sclerosis (MS) is widely considered as an autoimmune disease characterized by an inflammatory attack on the myelin sheath, leading to demyelination
and axonal damage. Although its cause remains unknown, it is currently believed that T cells reactive to
myelin components provide the organ specificity of the
pathogenic process.1 In particular, T cells recognizing
the immunodominant peptides of myelin basic protein
(MBP) are frequently detected in MS patients. Although MBP-reactive T cells are also found in healthy
individuals, there is evidence that these T cells undergo
in vivo activation and clonal expansion in peripheral
blood, as well as in cerebrospinal fluid (CSF) in patients with MS, as opposed to healthy individuals.2–5
Expansion of V␤5.2/5.3⫹ T cells has been demonstrated in peripheral blood,6,7 cerebrospinal fluid
(CSF),8,9 and brain lesions10 of MS patients. Although
controversial, these findings have been most consistently found in patients with the human leukocyte antigen (HLA) haplotype DR2.7 Furthermore, it has
been shown that these T cells can be activated by
MBP, whereas depletion of V␤5.2/5.3⫹ T cells in vitro
has been accompanied by a decrease in MBP reactivity.8
From the 1Department of Neurology, 2MS-MRI Center, and 3Image Analysis Center (IAC), VU Medical Center, Amsterdam, The
Netherlands; 4Karolinska Hospital, Stockholm; 5Akademiska Hospital, Uppsala; 6Huddinge University Hospital, Huddinge; 7University Hospital, Linköping; 8AstraZeneca AB, AstraZeneca R & D
Södertälje; and 9Queens Medical Center, Nottingham, UK.
Published online Feb 19, 2002 in Wiley InterScience
(www.interscience.wiley.com). DOI: 10.1002/ana.10146
Address correspondence to Dr Polman, VU Medical Center, Department of Neurology, P.O. Box 7057, 1007 MB, Amsterdam,
The Netherlands. E-mail: ch.polman@vumc.nl
Received Aug 1, 2001, and in revised form Dec 7. Accepted for
publication Dec 7, 2001.
© 2002 Wiley-Liss, Inc.
467
On the basis of these observations, a humanized antibody (mAb), ATM-027, specifically targeting the
V␤5.2/5.3⫹ T cells was developed. In the first study
with ATM-027 in humans, on average 70% of the target cell population was depleted, whereas T-cell receptor (TCR) density in the remaining cells was downregulated.11 ATM-027 treatment decreased the number
of interferon-␥ (IFN-␥), but not interleukin-10 (IL-10)
mRNA-expressing peripheral blood mononuclear
cells.12 Furthermore, target cell depletion was accompanied by a decrease in reactivity to several MBP peptides.12 In the present study, we present the results of a
subsequent phase II clinical trial in which the safety,
tolerability, and efficacy of multiple dose administration of ATM-027 for 6 months were evaluated in
relapsing-remitting (RR) MS patients. Efficacy was
measured by the number and volume of active brain
lesions on magnetic resonance imaging (MRI) in a
baseline versus treatment design. An important study
objective was to evaluate whether depletion and TCR
downregulation of the target T cells would result in a
decrease of MRI lesion activity of at least 60%. Immunological assessments were performed to elucidate further the mechanism of action of ATM-027 in RRMS.
Patients and Methods
Study Design and Patient Characteristics
This multi-center study involved six centers, in the Netherlands, United Kingdom, and Sweden. The study started with
a 4-month run-in period, followed by a 6-month treatment
period with monthly clinical and MRI examinations and immunological assessments. A 7-month follow-up period ended
the study and included three additional MRI scans. Fiftynine RRMS patients were enrolled and stratified according
to DR2 status. The sample size of at least 20 patients in each
stratum was based on the assumption that a treatment effect
of 60% should be detectable at a 5% significance level with
a power of approximately 80%. Efficacy was measured as the
percentage of change in number and volume of active MRI
lesions from baseline. To allow for unbiased assessment of
safety and tolerability, 6 additional patients in each stratum
were randomly selected to receive placebo. According to the
inclusion and exclusion criteria, patients had clinically definite MS;13 had at least two clinical relapses or one clinical
relapse and one separate subclinical relapse as documented
with at least one enhancing lesion on MRI during the 36
months before entry in the study and an Expanded Disability Status Scale (EDSS) score of ⱕ5.14 MRI changes highly
suggestive of MS were required (either nine or more brain
lesions on T2-weighted images or four or more T2 brain
lesions, of which at least one showed gadolinium enhancement before inclusion). A level of at least 1 % V␤5.2/5.3⫹ T
cells in peripheral blood (percentage of total CD3⫹ T cells)
was also required. None of the patients received treatment
with immunomodulatory agents, including interferon-␤,
within 6 months before inclusion.
468
Annals of Neurology
Vol 51
No 4
April 2002
Study Drug
ATM-027 is a recombinant humanized IgG1 developed under license from Avant Immunotherapeutics. Purified bulk
material was produced by Lonza Biologics plc (UK). The
study drug was provided as a solution for intravenous injection (6ml) at three different concentrations: 1.0mg/ml,
2.5mg/ml, and 5.0mg/ml in isotonic 0.01mol/L citrate
buffer. The placebo was a solution for injection of identical
appearance, consisting of isotonic 0.01mol/L citrate buffer.
ATM-027 and placebo were administered as a short (5minute) injection.
Treatment Regimen
The aim of the present study was to keep the total number
of V␤5.2/5.3⫹ T cells at ⬍1.2 % of the total CD3⫹ T-cell
population and TCR density on the remaining target cells of
⬍20% of normal (TCR-low). Target cells with a TCR density of 20 to 100% of normal were denoted TCR-high. No
target cells with normal TCR expression were to be present
in the circulation.
All patients received 6 monthly injections. All patients
randomized to ATM-027 received a starting dose of 6mg.
Subsequent dosing was based on both the levels of target
cells and their TCR expression, as measured by flow cytometry 3 days before the next dose was scheduled. If the total
level of V␤5.2/5.3⫹ T cells was ⬎1.2% or the level of
V␤5.2/5.3⫹ T cells with TCR-high density was ⬎0.3%, the
patient was to receive another dose of ATM-027. If not, patients received placebo.
A secondary aim of the dose regimen was to find a dose
that depleted target cells for more than 4 weeks. Thus, if the
starting dose of 6mg did not result in target cell depletion for
4 weeks, the dose was increased to 15mg at the next injection. A final dose adjustment up to 30mg was permitted
(Fig 1).
Safety Assessments
All adverse events were recorded continuously throughout
the study. Safety laboratory measurements were performed
monthly throughout the run-in and treatment period. Physical examinations were performed both before and after each
injection, as well as during follow-up. A standard electrocardiogram was performed at enrollment and at the end of the
treatment period.
MRI Acquisition and Analysis Protocol
MRI evaluation of MS lesions was in accordance with published guidelines for exploratory trials in established MS.15
Starting at enrollment and ending 4 months after the end of
the treatment period, lesion activity was assessed by 14
monthly gadolinium-enhanced brain MRI scans for the
number and volume of enhanced lesions. Five scans were obtained before treatment (⫺4, ⫺3, ⫺2, ⫺1, and baseline)
and six scans during treatment (1, 2, 3, 4, 5, and 6), with an
additional three scans during extended follow-up (7, 8, and
9). MR imaging included contiguous 3mm slices with a
1mm in-plane resolution using T1-weighted spin-echo images and dual-echo T2-weighted turbo spin-echo images obtained after injection of 0.2mmol/kg gadolinium DTPA.
Evaluation of all scans performed was done at the Image
Fig 1. Possible treatment regimen scenarios for the 47 ATM-027 treated multiple sclerosis patients. The maximum doses administered to achieve the aims of the individual dose titration were 6mg in 21 patients, 15mg in 19 patients, and 30mg in 7 patients.
Analysis Center, VU Medical Center, Amsterdam, and was
blinded according to patient identification, HLA-DR2 status,
and treatment. The order of the scans was also blinded to
the evaluators by assigning a random code to each scan; this
allowed all scans of a given patient to be analyzed without
knowledge of the order of scanning. Enhancing lesions were
marked and counted according to established guidelines16 by
two raters in consensus; their lesion volume was measured
using local thresholding software (Show
Images).
Blood and CSF Sampling
Blood samples were collected throughout the study for (1)
flow cytometry assessment of T-lymphocyte subpopulations
expressing V␤5.2/5.3 T-cell receptors; (2) analysis of ATM027 and treatment-induced antibodies; and (3) exploratory
immunological assessments. CSF sampling was optional.
CSF samples for V␤5.2/5.3 phenotyping were collected 1
month before the start of treatment and 6 months after the
first injection.
Target Cell Analysis in Peripheral Blood and CSF
The target V␤5.2/5.3⫹ T-cell subset was analyzed by twocolor flow cytometry in blood and CSF. Analyses were performed at the Department of Hematology, VU Medical
Center, Amsterdam, or at the Flow Cytometry Unit, Nova
Medical AB, Clinical Trials Center, St Görans Hospital,
Stockholm. Dose dependent presence of ATM-027 on the
target cell surface following in vivo treatment precluded the
use of a fluorochrome-conjugated primary mAb for proper
target cell analysis. Thus, the V␤5.2/5.3⫹ T cells were analyzed by indirect staining, using ATM-027 as the primary
antibody to saturate all target TCR molecules on the cell
surface, followed by a FITC-conjugated F(ab)2 fragment of
goat anti-human IgG, Fc specific (Immunotech, France).
This reagent does not cross-react with mouse mAb and thus
will not bind to the CD3 mAb (PerCP-conjugated, Becton
Dickinson Immunocytometry Systems, CA) used concomitantly in the same tube. By this procedure, the staining al-
ways revealed the total cell surface expression of the TCR
V␤5.2/5.3, even after in vivo exposure to ATM-027. The
results are presented as the proportion of target cells within
the CD3⫹ T-cell population.
Analysis of ATM-027 and Anti-ATM-027
Concentrations of ATM-027 were determined in plasma and
CSF, using a competitive immunoassay with Europiumlabeled ATM-027 as a tracer. Analysis of treatment-induced
anti-ATM-027 antibodies in plasma was performed using a
double antigen sandwich immunoassay.
Autoantigen Reactivity Measured with ELISPOT for
Detection of Single Cells Secreting IFN-␥
Because of the necessity of using fresh cells for both this
assay and the assay described in the next section, only patients studied in Sweden were included. The ELISPOT assay
was performed essentially as described earlier.17 The antigens
used were peptides of myelin basic protein (MBP), myelin
oligodendrocyte glycoprotein (MOG), acetylcholine receptor
(AChR-␣, used as the negative control peptide), and purified
protein derivative (used as the positive control antigen).
Background control cultures received no antigen. The following peptides were selected based on their previous documented role as T-cell epitopes either in human MS or in
experimental autoimmune encephalomyelitis:
MBP 1–20 (ASQKRPSQRHGSKYLATAST)
MBP 80 –102 (TQDENPVVHFFKNIVTPRTPPPS)
MBP 131–153 (ASDYKSAHKGFKGVDAQGTLSKI)
MBP 142–167 (KGVDAQGTLSKIFKLGGRDSRSGSPM)
MOG 14 –39 (ALVGDEVELPCRISPGKNATGMEVGW)
MOG 63– 87 (PEYRGRTELLKDAIGEGKVTLRIRN)
AChR-␣ 60 – 80 (WVDYNLKWNPDDYGGVKKIHI)
The mean number of spots, corresponding to single cells
that had secreted IFN-␥, was expressed as the number of
IFN-␥-secreting cells per 105 peripheral blood lymphocytes
Killestein et al: Suppression of V␤5.2/5.3⫹ T Cells in Multiple Sclerosis
469
(PBL) initially added to each well. The number of specific
IFN-␥-secreting cells was calculated by subtracting the number of IFN-␥-secreting cells obtained in control wells containing media alone from the total number of IFN-␥secreting cells obtained for each antigen stimulation.
Cellular Cytokine mRNA Expression
A mixture of four different synthetic oligonucleotide probes
complementary to mRNA for tumor necrosis factor-␣ (TNF␣), IFN-␥, IL-10, and TGF-␤ was used with sequences and
methodology as described previously.18 A probe complementary to an IFN-␥ antisense probe was used as negative control. Data were expressed as numbers of cytokine mRNApositive cells per 105 plated PBL.
Statistics
The main efficacy variables were the within-patient changes
in the mean number and mean volume of enhanced brain
lesions during the run-in period compared with the treatment period. For the proof of concept (PoC) analysis only
those patients who fulfilled the following two criteria: (1)
target cell depletion successful, and (2) at least one active
lesion detected during run-in. The Wilcoxon signed-rank test
was used to test the hypothesis of no treatment effect based
on the median of the within-patient changes. The effect size
expressed as a percentage of the run-in level was calculated as
the median of the distribution of individual percentage
changes. Corresponding 95% confidence levels were derived
from the 2.5 and 97.5 percentiles in the bootstrap distribution for the median of the distribution of individual percentage changes using 10,000 bootstrap samples. This method
was chosen because the symmetry assumption for a HodgesLehmann procedure for estimation associated with the Wilcoxon signed-rank test was clearly not fulfilled for the MRI
variables. For comparison of MRI variables between HLADR2⫹ and DR2⫺ subgroups, the two-sample Wilcoxon
rank-sum test was used. Exploratory variables were analyzed
by use of the Wilcoxon signed rank test with the associated
Hodges-Lehmann estimates and 95% confidence intervals.
Results
Patient characteristics of all patients included are given
in Table 1. Forty-seven patients were treated with
ATM-027, 27 of them being HLA-DR2⫹ and 20
HLA- DR2⫺. Twelve patients were treated with placebo, six of each stratum. Thirteen patients were ex-
cluded from the PoC analysis, two because target cell
depletion was incomplete and 11 due to lack of enhanced lesions during run-in.
Safety and Tolerability of ATM-027
The study drug was well tolerated. Two patients discontinued treatment because of adverse events and another two did not take part in the follow-up. A total
number of 13 serious adverse events (SAEs) were reported during the study, three of which were judged by
the investigator to have a possible causal relationship
with the study drug (Table 2). Most adverse events
(AEs) were classified as being of mild or moderate intensity and could not be clearly related to study drug
administration, neither to the time of dosing or to the
dose given. Seven patients of a total of 47 receiving
active treatment reported flu-like symptoms, occurring
at variable intervals in relation to the injection of study
drug. There were no treatment-related changes in
physical examination, supine or standing heart rate, supine or standing blood pressure, body temperature,
blood chemistry, or electrocardiograms.
V␤5.2/5.3⫹ T-Cell Depletion
The plasma concentrations of ATM-027 increased with
increasing doses in a proportional fashion. Target
T-cell depletion and TCR down regulation were
achieved in all patients on treatment (Fig 2). In patients in the active treatment group, levels of V␤5.2/
5.3⫹ T cells were reduced from approximately 2.4%
before start of treatment, to slightly below 1% during
the treatment (see Fig 2). This level remained low also
during the follow-up phase, whereas the receptor density recovered within 5 months after the end of treatment (data not shown). The level of V␤5.2/5.3⫹ T
cells in CSF was reduced in all treated patients for
whom CSF was available (n ⫽ 6, data not shown).
Only two patients developed anti-ATM-027 indicating
a low immunogenicity of ATM-027.
MRI and Clinical Parameters
During run-in, active lesions were found in 78.7%
(37/47) of patients treated with ATM-027. The mean
Table 1. Patient Characteristics
Treatment
ATM-027
HLA DR2 type
Mean age (SD)
Sex M/F (%)
Mean EDSS (baseline) (SD)
Mean no. of relapses 36 months
before entry in study (SD)
⫹ n ⫽ 27
38.4 (6.8)
30/70
2.3 (1.4)
3.6 (1.8)
⫺ n ⫽ 20
37.3 (7.0)
35/65
2.3 (1.2)
3.2 (1.0)
Subtotal
(n ⫽ 47)
37.9 (6.8)
32/68
2.3 (1.3)
3.4 (1.5)
Placebo
⫹n⫽6
41.2 (9.9)
33/67
2.4 (1.0)
2.8 (1.3)
⫺n⫽6
40.1 (6.9)
17/83
2.5 (0.9)
2.7 (0.8)
Subtotal
(n ⫽ 12)
Total
(n ⫽ 59)
40.7 (8.2)
25/75
2.5 (0.9)
2.8 (1.1)
38.5 (7.1)
31/69
2.4 (1.2)
3.3 (1.4)
EDSS ⫽ Expanded Disability Status Score; HLA ⫽ human leukocyte antigen; SD ⫽ standard deviation; M/F ⫽ male/female.
470
Annals of Neurology
Vol 51
No 4
April 2002
number of enhanced lesions in the PoC population decreased from 5.06 (SD: 6.60) during run-in, to 3.89
(SD: 4.65) during treatment, whereas the mean volume of enhanced lesions decreased from 531 mm3
(SD: 753) to 466 mm3 (SD: 616). No statistically significant difference in any parameter was detected (Table 3). The observed effect size was in the range of 10
to 30% compared with the targeted 60% response (see
Fig 2).
The Wilcoxon signed-rank test for paired comparisons was used to investigate whether there were any
changes in the efficacy variables from the run-in period
to the different time points during treatment phase and
the follow-up period. The effect was not statistically
significant in any of the analyses performed. Nor was
there any trend toward increasing effect at the later
stage of the treatment period that could indicate a delayed response. Furthermore, individual data did not
suggest any correlation between degree of target cell
depletion and effect on MRI. No changes of MR parameters in placebo treated patients were found.
The number of relapses occurring in the different
periods of study was 21 during run-in (16 ATM-027,
5 placebo), 29 during treatment (24 ATM-027, 5 placebo) and 24 during follow-up (18 ATM-027, 6 placebo). The duration of this trial was too short for a
clinically meaningful change in EDSS to occur.
Differences between HLA-DR2 Haplotypes
No statistical significance was detected in the change
from baseline to treatment between the two HLA-DR2
types (Fig 3).
Table 2. Serious Adverse Events in Patients Treated with
ATM-027 and Placebo
Serious Adverse Events
Run-in period
Positive cervical smear test
Tension headache
Treatment period (n ⫽ 4)
Postoperative bleeding
MS relapse (n ⫽ 3)
Follow-up period (n ⫽ 7)
Traumatic injury
Deep-venous thrombosis
Arm fracture
MS relapse (n ⫽ 3)a
Tonsillitis
Treatment Group
(n ⫽ 2)
n.a.
n.a.
Autoantigen Reactivity Measured with ELISPOT
Peptides from MOG and MBP induced increased
numbers of single cells secreting IFN-␥ as compared
with the control peptide ACHR, confirming an increased autoreactivity to myelin antigens in RRMS.
Most V␤5.2/5.3⫹ depleted patients displayed lower
reactivity to peptides from both MOG and MBP, as
measured by the number of single cells secreting IFN-␥
during treatment compared with baseline. Changes
from mean baseline values for the different autoantigens used are given in Table 4. Although no changes
were observed in the placebo group, the numbers obtained were too small to allow meaningful interpretations.
Cellular mRNA Cytokine Expression
Changes in TNF-␣, IL-4, IL-10, and IFN-␥ mRNA
expression are given in Table 5. A transient decrease
was found in the number of IFN-␥ mRNA expressing
cells during treatment. Similar patterns were found for
TNF-␣. IL-4 remained constant throughout the (pre-)
treatment and posttreatment phase, whereas most patients showed a slight transient increase in the number
of IL-10 mRNA-expressing cells during treatment.
Discussion
In this phase II clinical trial of the humanized antibody
ATM-027, suppression of target cells, ie, V␤5.2/5.3⫹
T cells in combination with a TCR downregulation of
the remaining target cells was achieved. No safety concerns emerged during the trial and the study drug was
generally well tolerated. However, the efficacy results of
the study gave clear evidence that the target of 60%
reduction in MRI activity could not be attained. An
effect size on the MRI variables in the range of 10 –
Fig 2. Mean number of enhancing lesions (⫾SEM) and mean
percentage of V␤5.2/5.3⫹ T cells (⫾SEM) during run-in and
treatment phase in ATM-027 proof of concept population
(n ⫽ 37).
ATM-027
Placebo (n ⫽ 2); ATM-027
(n ⫽ 1)
Placebo
ATM-027
ATM-027
ATM-027 (n ⫽ 2); placebo
(n ⫽ 1)
ATM-027
a
A total number of 13 serious adverse events were reported, three of
which were judged as having a possible causal relationship with the
study drug (MS relapse, requiring hospital admittance)
MS ⫽ multiple sclerosis.
Killestein et al: Suppression of V␤5.2/5.3⫹ T Cells in Multiple Sclerosis
471
Table 3. Number of Enhanced Lesions, Proof of Concept Analysis Set, ATM-027-Treated Patients (n ⫽ 37)
Variable
Period
Mean
(SD)
No. of
lesions
Volume
(mm3)
Run-in
Treatment
Run-in
Treatment
5.06 (6.60)
3.89 (4.65)
531 (753)
466 (616)
Mean Change
(SD)
Median
(Range)
Median Change
(Range)
pa
Effect Size
(95% CL)b
2.00 (0–25)
⫺1.18 (4.98) 2.00 (0–21)
⫺0.50 (⫺17–9)
0.127 ⫺33.3% (⫺45.1–33.3)
221 (12–2998)
⫺65 (697) 253 (0–2771)
⫺6 (⫺2365–1336) 0.558 ⫺10.3% (⫺52.1–67.0)
Within-patient change of mean number and mean volume of brain lesions between the run-in period and the treatment period
a
Wilcoxon signed-rank test.
Calculated from 10,000 bootstrap samples.
b
SD ⫽ standard deviation.
30% can not be definitely excluded. However, given
the run-in versus treatment design of the study, such
an effect might also reflect the natural course of the
disease (regression to the mean). Given the sample size
and the number of enhancing lesions observed during
run-in, the current study has been sufficiently powered
to conclude that the likelihood of a false-negative result
is minimal.
The exploratory immunological assays performed
here include phenomena of possible importance in MS.
The results suggest that IFN-␥ expression is connected
to V␤5.2/5.3 usage. Whether a decreased in vivo production of IFN-␥ would be beneficial or detrimental to
MS patients remains an open question. However, since
there are several arguments suggesting that IFN-␥ may
be harmful in MS,3 the observed decrease in number
of cells expressing mRNA of this cytokine might have
been beneficial. However, a decrease was not seen in all
patients and was not related to a significant effect on
MRI.
Fig 3. Mean number of enhancing lesions (⫾SEM) in ATM027-treated multiple sclerosis patients (proof of concept population, n ⫽ 37, patients stratified according to human leukocyte
antigen (HLA)-DR2 status). No statistical difference was
found in the change from baseline to treatment between the 2
HLA-DR2 types.
472
Annals of Neurology
Vol 51
No 4
April 2002
So far, different strategies have been applied to selectively suppress autoreactive T cells in MS. Recently,
treatment of MS patients with a humanized antileukocyte mAb (CAMPATH-1H) suppressed MRIdocumented disease activity.19 The depleted lymphocyte pool was reconstituted with cells having decreased
IFN-␥ secretion, in line with the findings of our study.
However, one-third of the patients developed
Campath-1H-mediated thyroid autoimmunity.20 Unlike Campath-1H, another trial using an anti-CD4⫹
T-cell-depleting mAb did not suppress MRIdocumented disease activity.21 It was suggested that
treatment with CD4 mAb did not eliminate those cells
most strongly involved in the disease process, ie,
primed, IFN-␥ producing T-helper (TH)-1 cells.22
More recently, two clinical trials testing the ability of
an altered peptide ligand (APL) derived from MBP to
reduce disease activity in MS have been reported. Kappos and colleagues23 reported that enhancing lesions
were reduced in MS patients receiving low doses of
APL. However, this trial was terminated because of
high incidence of immediate type hypersensitivity reactions. Bielekova and colleagues24 reported that APL
treatment led to an increase in exacerbation rate in 3 of
8 patients studied. T-cell populations specific for MBP
expanded in these 3 patients. Another approach to deplete circulating MBP-reactive T cells in MS has been
vaccination with irradiated T cells reactive to
MBP,25,26 or a TCR peptide vaccine from the V␤5.2
sequence.27
In our study, only a small subpopulation of T cells
was depleted. It is very unlikely that this form of depletion would render the individual more susceptible
to serious side effects, as was the case in some of the
more general T-cell-directed trials described
above.20,23,24
Although it has been reported that MBP responsive
TCR V␤5⫹ genes are used more frequently in MS patients than in non-MS patients, other studies did not
detect any expansion within the V␤5⫹ T cells in MS
patients (for review see Offner and colleagues28). Enrichment of T cells expressing various other TCR V␤
Table 4. Means of Percentage Changes from Baseline in MBP and MOG Peptides, AChR-␣ and PPD Reactivity (ELISPOT,
Number of Single Cells Secreting Interferon-␥/100,000 cells), Estimated with Hodges-Lehmann
and Corresponding 95% Confidence Interval
Difference
n
H-L
Lower
Limit
Upper
Limit
54 days–BL
166 days–BL
54 days–BL
166 days–BL
54 days–BL
166 days–BL
54 days–BL
166 days–BL
54 days–BL
166 days–BL
54 days–BL
166 days–BL
54 days–BL
166 days–BL
54 days–BL
166 days–BL
18
18
18
18
18
18
18
17
18
18
18
18
18
18
18
18
⫺0.3
⫺1.8
⫺1.8
⫺1.5
⫺3.8
⫺3.5
⫺2.5
⫺3.0
⫺2.0
⫺3.3
⫺2.0
⫺2.3
⫺1.0
⫺0.8
⫺1.5
⫺6.8
(⫺2.5
(⫺3.5
(⫺4.8
(⫺7.0
(⫺7.8
(⫺7.3
(⫺4.3
(⫺6.5
(⫺6.3
(⫺6.5
(⫺5.5
(⫺5.8
(⫺2.5
(⫺3.0
(⫺18.5
(⫺21.0
0.5)
0.0)
⫺0.5)
0.0)
⫺0.5)
⫺0.8)
⫺1.0)
⫺1.0)
⫺0.8)
⫺1.0)
⫺0.5)
0.0)
⫺0.3)
0.3)
2.5)
2.5)
Variable
MBP 1–20
MBP 80–102
MBP 131–153
MBP 142–167
MOG 14–39
MOG 63–87
AChR-␣
PPD
MBP ⫽ myelin basic protein; MOG ⫽ myelin oligodendrocyte glycoprotein; AChR-␣ ⫽ acetylcholine receptor-␣; PPD ⫽ purified protein
derivative; BL ⫽ baseline; H-L ⫽ Hodges-Lehman.
chains has also been reported.9,28 –30 Moreover, different V␤ segments are to some extent functionally interchangeable, suggesting that the observed biases in
TCR-V␤ expression in response to antigen reflect a
preferred, rather than a required, combination of ␤
gene segments.28 Furthermore, lack of restriction of
TCR-␤ variable gene usage has been reported in CSF
lymphocytes in acute optic neuritis.31 This may imply
either that MS is not a V␤ restricted disease event at
onset or that the autoimmune response has widened
before the disease becomes clinically manifest (epitope
spreading).
In conclusion, the results from this phase II study
show that treatment with ATM-027, resulting in profound downregulation of V␤5.2/5.3⫹ T cells, is safe
and well tolerated. Decreased numbers of cells expressTable 5. Means of the Percentage Changes from Baseline in
TNF-␣, IL-4, IL-10, and IFN-␥ mRNA Expression,
Estimated with Hodges-Lehmann and Corresponding 95%
Confidence Interval
Variable
Difference
n
H-L
Lower
Limit
Upper
Limit
TNF-␣
54 days–BL
166 days–BL
54 days–BL
166 days–BL
54 days–BL
166 days–BL
54 days–BL
166 days–BL
23
22
20
22
23
22
23
22
⫺1.0
⫺3.0
0.0
0.0
1.0
2.0
⫺5.0
⫺7.0
(⫺3.0
(⫺6.0
(⫺1.0
(⫺1.0
(⫺1.0
(⫺1.0
(⫺12.0
(⫺12.0
1.0)
0.0)
2.0)
1.0)
4.0)
4.0)
0.0)
⫺2.0)
IL-4
IL-10
IFN-␥
TNF-␣ ⫽ tumor necrosis factor; IL-4 ⫽ interleukin-4; IFN-␥ ⫽
interferon-␥; H-L ⫽ Hodges-Lehmann.
ing IFN-␥ mRNA and decreased T-cell reactivity to
several myelin antigens were found in ATM-027
treated patients. However, the reduction of disease activity as measured on MRI did not reach levels of statistical significance.
This study was supported by AstraZeneca R & D Södertälje, Södertälje, Sweden (to FB and CHP).
References
1. Martino G, Hartung HP. Immunopathogenesis of multiple
sclerosis: the role of T cells. Curr Opin Neurol 1999;12:
309 –321.
2. Steinman L, Waismann A, Altman D. Major T cell responses in
multiple sclerosis. Mol Med Today 1995;1:79 – 83.
3. Olsson T. Critical influences of the cytokine orchestration on
the outcome of myelin antigen-specific T-cell autoimmunity in
experimental autoimmune encephalomyelitis and multiple sclerosis. Immunol Rev 1995;144:245–268.
4. Olsson T, Zhi WW, Hojeberg B, et al. Autoreactive T lymphocytes in multiple sclerosis determined by antigen- induced
secretion of interferon-gamma. J Clin Invest 1990;86:981–985.
5. Martin R, McFarland HF, McFarlin DE. Immunological aspects of demyelinating diseases. Annu Rev Immunol 1992;10:
153–187.
6. Kotzin BL, Karuturi S, Chou YK, et al. Preferential T-cell receptor beta-chain variable gene use in myelin basic proteinreactive T-cell clones from patients with multiple sclerosis. Proc
Natl Acad Sci U S A 1991;88:9161–9165.
7. Musette P, Bequet D, Delarbre C, et al. Expansion of a recurrent V beta 5.3⫹ T-cell population in newly diagnosed and untreated HLA-DR2 multiple sclerosis patients. Proc Natl Acad
Sci U S A 1996;93:12461–12466.
8. Ferm M, Issazadeh S, Wallstrom E, et al. Biased usage of TCR
V beta 5.2/5.3 by T cells in the CSF and among PBMC with
spontaneous and MBP 80 –102 induced IFN gamma expression
in MS patients (abstract). Revue Neurologique 2000;156:3S75.
Killestein et al: Suppression of V␤5.2/5.3⫹ T Cells in Multiple Sclerosis
473
9. Lozeron P, Chabas D, Duprey B, et al. T cell receptor V beta
5 and V beta 17 clonal diversity in cerebrospinal fluid and peripheral blood lymphocytes of multiple sclerosis patients. Mult
Scler 1998;4:154 –161.
10. Oksenberg JR, Panzara MA, Begovich AB, et al. Selection for
T-cell receptor V beta-D beta-J beta gene rearrangements with
specificity for a myelin basic protein peptide in brain lesions of
multiple sclerosis. Nature 1993;362:68 –70.
11. Edenius C, Samuelson P, Arfors L, et al. Selective in vivo depletion of TCR V beta 5.2/5.3 expressing T cells in patients
with multiple sclerosis (abstract). Revue Neurologique 2000;
156:3S121.
12. Olsson T, Arfors L, Ferm M, et al. Selective in vivo depletion
of TCR V beta 5.2/5.3 T cells in MS patients reduces IFN
gamma mRNA expression and MBP 80 –102 reactive T cells
(abstract). Revue Neurologique 2000;156:3S79.
13. Poser CM, Paty DW, Scheinberg L, et al. New diagnostic criteria for multiple sclerosis: guidelines for research protocols.
Ann Neurol 1983;13:227–231.
14. Kurtzke JF. Rating neurologic impairment in multiple sclerosis:
an expanded disability status scale (EDSS). Neurology 1983;33:
1444 –1452.
15. Miller DH, Albert PS, Barkhof F, et al. Guidelines for the use
of magnetic resonance techniques in monitoring the treatment
of multiple sclerosis. US National MS Society Task Force. Ann
Neurol 1996;39:6 –16.
16. Barkhof F, Filippi M, van Waesberghe JH, et al. Improving
interobserver variation in reporting gadolinium-enhanced
MRI lesions in multiple sclerosis. Neurology 1997;49:1682–
1688.
17. Kabilan L, Andersson G, Lolli F, et al. Detection of intracellular expression and secretion of interferon-gamma at the singlecell level after activation of human T cells with tetanus toxoid
in vitro. Eur J Immunol 1990;20:1085–1089.
18. Link J, Soderstrom M, Olsson T, et al. Increased transforming
growth factor-beta, interleukin-4, and interferon-gamma in
multiple sclerosis. Ann Neurol 1994;36:379 –386.
19. Coles AJ, Wing MG, Molyneux P, et al. Monoclonal antibody
treatment exposes three mechanisms underlying the clinical
course of multiple sclerosis. Ann Neurol 1999;46:296 –304.
20. Coles AJ, Wing M, Smith S, et al. Pulsed monoclonal antibody
treatment and autoimmune thyroid disease in multiple sclerosis.
Lancet 1999;354:1691–1695.
474
Annals of Neurology
Vol 51
No 4
April 2002
21. van Oosten BW, Lai M, Hodgkinson S, et al. Treatment of
multiple sclerosis with the monoclonal anti-CD4 antibody cMT412: results of a randomized, double-blind, placebo-controlled,
MR- monitored phase II trial. Neurology 1997;49:351–357.
22. Rep MH, van Oosten BW, Roos MT, et al. Treatment with
depleting CD4 monoclonal antibody results in a preferential
loss of circulating naive T cells but does not affect IFN-gamma
secreting TH1 cells in humans. J Clin Invest 1997;99:
2225–2231.
23. Kappos L, Comi G, Panitch H, et al. Induction of a nonencephalitogenic type 2 T helper-cell autoimmune response in
multiple sclerosis after administration of an altered peptide ligand in a placebo-controlled, randomized phase II trial. Nat
Med 2000;6:1176 –1182.
24. Bielekova B, Goodwin B, Richert N, et al. Encephalitogenic
potential of the myelin basic protein peptide (amino acids
83–99) in multiple sclerosis: results of a phase II clinical trial
with an altered peptide ligand. Nat Med 2000;6:1167–1175.
25. Medaer R, Stinissen P, Truyen L, et al. Depletion of myelinbasic-protein autoreactive T cells by T-cell vaccination: pilot
trial in multiple sclerosis. Lancet 1995;346:807– 808.
26. Zhang J, Medaer R, Stinissen P, et al. MHC-restricted depletion of human myelin basic protein-reactive T cells by T cell
vaccination. Science 1993;261:1451–1454.
27. Vandenbark AA, Chou YK, Whitham R, et al. Treatment of
multiple sclerosis with T-cell receptor peptides: results of a
double-blind pilot trial. Nat Med 1996;2:1109 –1115.
28. Offner H, Vandenbark AA. T cell receptor V genes in multiple
sclerosis: increased use of TCRAV8 and TCRBV5 in MBPspecific clones. Intern Rev Immunol 1999;18:9 –36.
29. Gran B, Gestri D, Sottini A, et al. Detection of skewed T-cell
receptor V-beta gene usage in the peripheral blood of patients
with multiple sclerosis. J Neuroimmunol 1998;85:22–32.
30. Hong J, Zang YC, Tejada-Simon MV, et al. A common TCR
V-D-J sequence in V beta 13.1 T cells recognizing an immunodominant peptide of myelin basic protein in multiple sclerosis. J Immunol 1999;163:3530 –3538.
31. Heard RN, Teutsch SM, Bennetts BH, et al. Lack of restriction
of T cell receptor beta variable gene usage in cerebrospinal fluid
lymphocytes in acute optic neuritis. J Neurol Neurosurg Psychiatry 1999;67:585–590.
Документ
Категория
Без категории
Просмотров
1
Размер файла
111 Кб
Теги
monitored, mri, clinical, suppression, results, sclerosis, antibody, multiple, tria, phase, cells, mediated
1/--страниц
Пожаловаться на содержимое документа