A proof-of-concept study in refractory SLE patients to assess the immunological consequences of a combination treatment with rituximab (anti-CD20) and belimumab (anti-BAFF) to achieve long-term B-cell depletion. The immunological and clinical…
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Brief title
Condition
- Autoimmune disorders
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
In this proof-of-concept study the primary objective is to assess whether a
combination treatment of rituximab and belimumab will lead to a sustained
reduction of pathogenic autoantibodies and thereby inhibition of NET formation.
Therefore, the primary endpoints are:
- a sustained reduction of pathogenic autoantibodies, in particular anti-dsDNA
autoantibodies, at 24 weeks after treatment start
- an inhibition of the formation of NETs at 24 weeks after treatment start
Secondary outcome
The main secondary objective is to evaluate the effects of long-term B-cell
depletion which will involve assessments of the clinical response correlated
with immunological parameters. To this end, the relevant study parameters will
be evaluated after 4 weeks (short term), 24 weeks (intermediate term) and 104
weeks (long-term). The secondary endpoints measured at these times are:
- the effects on the reduction of pathogenic autoantibodies, in particular
anti-dsDNA autoantibodies
- the inhibition of the formation of NETs
- seroconversion of pathogenic autoantibodies, in particular anti-dsDNA
autoantibodies
- the normalization of complement usage, i.e. C3/C4 levels and C1Q-binding
Other secondary objectives are to evaluate:
- the safety and feasibility of the combination treatment according to the WHO
toxicity criteria
- the clinical response of refractory SLE patients upon long-term B-cell
depletion by:
* a reduction in SLEDAI scores, no new BILAG A involvement and the SLE
responder index
* in case of lupus nephritis: the number of partial and complete renal
responders
* the number of moderate or severe flares and renal flares
Background summary
Introduction
Systemic lupus erythematosus (SLE) affects predominantly young women with
childbearing potential (20-40 years) and inflammation can occur in virtually
every organ, including kidneys, lungs, heart or brain1. The disease course in
SLE patients is typically characterized by frequent flares, requiring
immunosuppressive treatment. SLE patients have an increased mortality with 1 of
8 patients dying within 8 years of follow-up, which is 2,5 times higher as the
general population 2. Moreover, it is estimated that 50-60% of all SLE patients
develop lupus nephritis, one of the more severe manifestations, in the first 10
years after diagnosis. These data emphasize the impact that SLE has in a young
patient population when, once diagnosed, means lifelong medical treatment and a
significant reduction of life expectancy. It also illustrates the need for
developing better means to prevent and treat the sequelae of SLE.
Current, evidence-based treatment modalities for SLE consist of
immunosuppressive treatment with high dose corticosteroids, cyclophosphamide or
mycophenol mycophenolate acid, that non-specifically target the immune system
to reduce inflammation 3. Side-effects of these treatment strategies are
(opportunistic) infections in the short term and risk for malignancy and
cardiovascular disease in the long-term. Treating SLE patients with biologicals
is an attractive alternative because biologicals specifically target the immune
system by blocking cytokines or deplete one specific cell population, thereby
reducing the risk for infections or malignancies as compared to conventional
immunosuppressants. Furthermore, the scarce treatment options underscore the
need to exploit new therapeutic possibilities for SLE patients who frequently
experience a flare of the disease. Recent advances in the knowledge of the
pathophysiology of SLE have identified the new immunological mechanism of
NETosis which potentially is at the heart of SLE pathogenesis. Therefore, we
set up the present study to investigate whether this process can be
successfully targeted in refractory SLE patients.
Anti-DNA autoantibodies and NETosis in SLE
Systemic lupus erythematosus (SLE) is a prototypic systemic autoimmune disease
in which the loss of tolerance to nucleic acids (=DNA) and their binding
proteins results in the generation of autoantibodies (e.g. anti-DNA,
anti-chromatin or anti-histone autoantibodies) that initiate and propagate
tissue-damaging inflammation involving almost every organ system 4. SLE can
present itself by a wide array of symptoms ranging from skin eruptions and
arthritis to life-threatening renal and cerebral involvement. Not only the
presence of autoantibodies against nuclear components implies that the humoral
immune system plays an important role in the pathophysiology, but also, the
recent approval of belimumab, a human antibody targeting the B-cell survival
cytokine BAFF (B-cell activating factor), for treatment in SLE patients 5;6.
Because autoantibodies against nuclear components are a central hallmark in the
diagnosis and prognosis of SLE, much research has focused on unraveling the
mechanisms underpinning the generation of these pathogenic autoantibodies. Two
crucial steps have been shown defective in SLE patients responsible for the
generation of autoantibodies: first, defects in B-cell tolerance have been
identified during B-cell selection in bone marrow (at the transition of early
immature B-cells to the immature B-cells) and in the peripheral lymphoid
tissues (at the transition of transitional B-cells to mature B-cells) 7.
Second, in SLE patients components of nuclear material, usually residing
intracellular and therefore not exposed to the immune system, have been found
in the extracellular space providing a crucial opportunity for the formation of
SLE-specific autoantibodies. Currently, three, not mutually excluding,
mechanisms are proposed for the presentation of nuclear autoantigens to the,
already tolerance defective, immune system in SLE: a) aberrant clearance of
apoptotic 8 and necrotic 9 cells can lead to the exposure of human DNA
components to the immune system 10; b) viral infections, often associated with
the initiation of flares 1, expose the immune system of lupus patients to
circulating viral RNA and DNA components; and c) recently, neutrophil
extracellular trap (NET) formation by neutrophils, recruited to infection
sites, is a crucial source of extracellular human DNA components 11;12. The
latter mechanism has been the most recent breakthrough in lupus research with
potential therapeutic consequences, as further explained below.
The formation of NETs by neutrophils has been described in 2004 showing the
formation of an extracellular structure that consists of threads of nuclear
chromatin-DNA 11. NETs were shown to be decorated by antimicrobial peptides
(AMPs) providing a highly immunogenic structure capable of killing invading
pathogens 13. This process is called NETosis, sound-related to *apoptosis*
because neutrophils die after extracellular disposing NETs. The relevance of
NET formation for SLE has only very recently come to the attention 12;14;15
when whole genome analysis observed that SLE patients over-expressed
granulopoiesis-specific genes (the so called *granulocyte signature*) and
IFN-regulated genes (the so called *IFN signature*) 16. The phenotypic
expression of the granulocyte signature was traced down to the presence of an
abnormal subset of neutrophils, so called low-density granulocytes (LDGs) in
the peripheral blood of SLE patients. Subsequently, it was found that LDGs
display an enhanced capacity to form NETs in comparison to normal density
SLE-derived and control neutrophils 15. Eventually, Garcia-Romo et al. found
that neutrophils of SLE patients underwent NETosis upon stimulation by immune
complexes from a well-known SLE-specific anti-nuclear antibody,
anti-ribonucleoprotein antibody (anti-RNP)12. Moreover, these NETS were able to
mount a secondary immune response through TLR7/9-mediated activation of
plasmacytoid dendritic cells. Taken together, enhanced NETosis triggered by
autoantibodies in SLE is at the heart of SLE disease pathogenesis.
Targeting NETosis in SLE
From a pathophysiological role, therapeutically interfering with the process of
NETosis in SLE is new. Recent studies have shown that the enhanced NET
formation correlates with disease severity such as renal involvement 17;18. It
has also been shown that NETs induce complement activation and are responsible
for the usage of C1q, C3 and C4 in active SLE 18. These studies are part of the
increasing evidence that suggest neutrophils are contributors to the
pathogenesis of SLE flares. Therefore, reducing NETosis in SLE has therapeutic
potential.
Because neutrophils form a crucial 1st line of defense in the human immune
system, non-selective targeting of neutrophils (by blocking their activity or
depleting their numbers) is not a desirable approach. However, because immune
complexes formed with SLE-specific autoantibodies trigger neutrophils to form
NETs, targeting the production of these autoantibodies by plasma cells is a
plausible treatment strategy. There are currently no trials using biologicals
to target autoreactive plasma cells in SLE. However, we previously showed that
disease-specific autoantibody production is susceptible to long-term B-cell
depletion through a 6-monthly fixed retreatment protocol with rituximab in
patients with rheumatoid arthritis 19. Rituximab in SLE patients is currently
only warranted in an off-label setting because a recent randomized trial did
not show superiority over placebo 20;21. Also, on a pathophysiological level,
B-cell depletion alone is not likely to interfere with the basic pathologic
mechanisms described above. On the contrary, B-cell depletion leads
intrinsically to a rise in B-cell survival factor (BAFF or Blys)22 where,
physiologically, increased BAFF levels are triggers for the bone marrow of
patients to regenerate new B-cells. Thus, in SLE patients treated with
rituximab the increased BAFF levels can lead to repopulation of autoreactive B
cell clones 23;24. Noteworthy is that the need for repetitive treatment with
rituximab in many autoimmune diseases is already undisputed 25. Therefore, in
order to induce long-term B-cell depletion in SLE patients the combined
treatment of rituximab with belimumab (which blocks BAFF) is a more potent and
logical therapy. In mice, this combination treatment of rituximab and belimumab
led to a more profound B-cell depletion due to the additional depletion of
rituximab-resistant B-cells and CD20 negative plasmablasts/-cells 26. In SLE
patients, add-on therapy with belimumab has been proven effective as
steroid-sparing maintenance treatment 5. These findings led to the present
study involving a proof-of-concept study in refractory SLE patients to assess
the immunological consequences of a combination treatment with rituximab
(anti-CD20) and belimumab (anti-BAFF).
Study objective
A proof-of-concept study in refractory SLE patients to assess the immunological
consequences of a combination treatment with rituximab (anti-CD20) and
belimumab (anti-BAFF) to achieve long-term B-cell depletion. The immunological
and clinical monitoring of refractory SLE patients include the quantification
of NETosis, the kinetics of B-cell and plasma cell depletion and SLE-specific
autoantibody levels. As secondary goals, this study will evaluate the safety
and feasibility of this combination treatment and assess the clinical response.
Study design
This is a single-center, non-randomized, phase 2A, proof-of-concept study to
evaluate the effects of a combination treatment with rituximab and belimumab.
This combination therapy is designed to induce long-term B-cell depletion to
achieve significant reduction of autoantibody-mediated immune complexes. In
addition to standard therapy, SLE patients will receive 2 infusions of
rituximab 1000 mg on day 0 and 14 (week 2) and belimumab on day 28 (week 4) ,
42 (week 6) and 56 (week 8), then every 28 days. The primary endpoint is at 24
weeks after which an extended follow-up will take place, for subjects
continuing belimumab, until 104 weeks after treatment start.
Rituximab and Belimumab will be administered intravenously according to the
manufacturer*s instructions. All subjects will continue standard therapy during
the study period. Clinical and immunological parameters will be assessed every
8-12 weeks. The study medication is not blinded for patients nor physicians.
The study intends to include 15 refractory SLE patients.
Intervention
Rituximab
Patients will be intravenously treated with Rituximab 1000mg on day 0 and day
14. Before every infusion of Rituximab patients will receive intravenous
methylprednisolon 100mg together with oral acetaminophen 1000 mg and
intravenous Tavegil 2 mg.
Belimumab
Patients will be intravenously treated with Belimumab 10mg/kg on day 28, day 42
and day 56. Thereafter, patients will receive Belimumab 10mg/kg every 4 weeks.
No pre-medication is administered
Study burden and risks
There may be a benefit for the subjects participating in this study. The
present study will only include SLE patients who will have no other treatment
options due to the refractoriness of their disease, intolerance to conventional
therapies or cumulative toxicity of current treatment. The use of rituximab
with belimumab can ameliorate disease activity with a possible reduction of
infectious complication as compared to conventional intensive immunosuppressive
treatment.
The risks related to study participation lies predominantly in the side effect
profile of the biologicals used, as extensively described in §6.4. At study
entry a renal biopsy is performed to diagnose refractory renal disease
associated with proliferative lupus nephritis. A renal biopsy will also
differentiate from other causes such as chronic glomerulosclerosis or extensive
chronic damage which is a relative contraindication to aggressive
immunosuppressive therapy because of a small change of regaining kidney
function. In most cases, the renal biopsy will likely already be performed as
part of routine clinical evaluation of an patient with the suspicion of a
refractory lupus nephritis.
Albinusdreef 2
Leiden 2333ZA
NL
Albinusdreef 2
Leiden 2333ZA
NL
Listed location countries
Age
Inclusion criteria
Subjects enrolled in the study must meet the following inclusion criteria:
1) age 18 years,
2) ACR diagnosis of SLE (1997 revised criteria, see appendix 1)
3) Severe SLE flare at screening (see also section 5.2.3.2.), defined as a situation in which 1 or more of the following criteria are met:
- Increase in SLEDAI (SLE Disease Activity Index) with 12 or more points
- New or worse SLE-related activity of major organs, i.e.: CNS-SLE (includes NPSLE), vasculitis, nephritis, pericarditis and/or myocarditis, myositis, thrombocytopenia < 60, hemolytic anemia < 4.4mmol/L (<=7.0g/dL).
4) Refractory disease, defined as persisting or progressive disease activity (SLEDAI > 6 points) despite conventional immunosuppressive treatment and 1 or more of the following criteria:
- failure of the initial induction treatment at six months, for which a switch to another induction therapy regime has already been carried out;
- intolerance or contraindication for cyclophosphamide and mycophenolate mofetil (MMF);
- exceeding a cumulative dose of 15 gram of cyclophosphamide;
- a second relapse within two years after start of the initial induction therapy
- a relative contraindication for high-dose oral or intravenous (iv) prednisone, such as avascular osteonecrosis, previous psychosis on corticosteroids, osteoporosis and/or severe obesity (BMI *35 kg/m2).
5) ANA seropositivity, as defined by a positive ANA-titer * 1:80, before and at screening :
- Positive test results from 2 independent time points within the study screening period; OR
- One positive historical test result and 1 positive result during the screening period. Historical documentation of a positive test of ANA (eg, ANA by HEp-2 titer, ANA by ELISA) must include the date of the test.
6) Anti-DNA seropositivity, as defined by a positive anti-dsDNA serum antibody * 30 IU/mL, before and at screening:
- Positive test results from 2 independent time points within the study screening period.
- One positive historical test result and 1 positive result during the screening period. Historical documentation of a positive test of anti-dsDNA (eg, anti-dsDNA by Farr assay or ELISA) must include the date of the test.
7) Immune-complex mediated complement usage, as defined by:
- a low C3 serum level * 0.9 g/L; OR
- a low C4 serum level * 95 mg/L; OR
- a reduced activation of the classical pathway < 75%
8) Female subjects are eligible to enter the study if she is:
- Not pregnant or nursing
- Of non-child-bearing potential (i.e. after hyseterectomy, postmenopausal, bilateral ovariectomy or documented bilateral tubal ligation or other permanent female sterilization procedure)
- Use of effective contraception:
* Complete abstinence from intercourse from 2 weeks prior to administration of the 1st dose of study agent until 16 weeks after the last dose of study agent (Sexual inactivity by abstinence must be consistent with the preferred and usual lifestyle of the subject. Periodic abstinence (e.g. calendar, ovulation, symptothermal, post-ovulation methods) and withdrawal are not acceptable methods of contraception); OR
* Consistent and correct use of 1 of the following acceptable methods of birth control for 1 month prior to the start of the study agent, during the study, and 16 weeks after the last dose of study agent:
o Oral contraceptive, either combined or progestogen alone
o Injectable progestogen
o Implants of levonorgestrel or etonogestrel
o Estrogenic vaginal ring
o Percutaneous contraceptive patches
o Intrauterine device (IUD) or intrauterine system (IUS) with <1% failure rate as stated in the product label
o Male partner sterilisation (vasectomy with documentation of azoospermia) prior to the female subject's entry into the study, and this male is the sole partner for that subject. For this definition, *documented* refers to the outcome of the investigator's/designee*s medical examination of the subject or review of the subject's medical history for study eligibility, as obtained via a verbal interview with the subject or from the subject*s medical records.
o Double barrier method: condom and occlusive cap (diaphragm or cervical/vault caps) plus spermicidal agent (foam/gel/film/cream/suppository)
* These allowed methods of contraception are only effective when used consistently, correctly and in accordance with the product label. The investigator is responsible for ensuring subjects understand how to properly use these methods of contraception.
* Female subjects using mycophenolate mofetil (MMF) should be made aware that MMF affects the metabolism of oral contraceptives and may reduce their effectiveness. As such, women receiving MMF who are using oral contraceptives for birth control should employ an additional method (e.g., barrier method).
Exclusion criteria
4.2. Exclusion criteria
Subjects will be excluded from participation if they meet any of the following exclusion criteria:
1) Active pregnancy, as proven by a positive urine beta-HCG test or a positive serum beta-HCG
2) Significant B-cell depletion (peripheral B-cell counts < 60x10E6)
3) Significant hypogammaglobulinemia (IgG < 4.0 g/L) or an IgA deficiency (IgA < 0.1 g/L)
4) Immunization with a live vaccine 1 month before screening
5) Active infection at time of screening, as follows:
- Hospitalization for treatment of infection within previous 2 months of day 0 of the study
- Use of parenteral (intravenous of intramuscular) antibiotics ( including anti-bacterials, anti-virals, anti-fungals or anti-parasitic agents) within previous 2 months of day 0 of the study
- Serological evidence of active viral hepatitis defined as: patients positive for HbsAg test or HBcAb or a positive hepatisits C antibody
6) Have a historically positive HIV test or test positive at screening for HIV
7) Have a history of a primary immunodeficiency
8) Have a history of an anaphylactic reaction to parenteral administration of contrast agents, human or murine proteins or monoclonal antibodies
9) Have any other clinically significant abnormal laboratory value in the opinion of the investigator
10) Have current drugs or alcohol abuse or dependence
11) Have an active malignant neoplasm or one in the history of the last 5 years
12) Have evidence of serious suicide risk including any history of suicidal behavior in the last 6 months and/or any suicidal ideation in the last 2 months or who, in the investigator*s opinion, pose a significant suicide risk
Design
Recruitment
Medical products/devices used
metc-ldd@lumc.nl
metc-ldd@lumc.nl
metc-ldd@lumc.nl
metc-ldd@lumc.nl
metc-ldd@lumc.nl
Followed up by the following (possibly more current) registration
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In other registers
| Register | ID |
|---|---|
| EudraCT | EUCTR2014-000488-42-NL |
| CCMO | NL48136.058.14 |