Clinical trial NCT04115098
Conditions: Axial Spondyloarthritis
Keywords: spondylitis
Sponsor: The University of Texas Health Science Center, Houston
Start date: 2020-06-25; Completion date: 2023-08-11
Enrollment: 42 participants; Allocation: RANDOMIZED; Intervention model: PARALLEL

Brief summary:
The purpose of this study is to compare selective cyclooxygenase-2 (COX-2) and non selective COX inhibitors with respect to the extent to which disease activity is improved without self reported, unacceptable side effects among individual patients with axial spondyloarthritis (AxSpA),to compare selective COX-2 and nonselective COX inhibitors impact on Health related Quality of Life (HrQOL) and how this relates to changes in disease activity and to conduct proteomic assessment of predictive biomarkers of non steroidal anti-inflammatory drug(NSAID) response

Detailed description:

Arms: arm 1: Each participant will be randomized to a different initial drug sequence (6 possibilities: ABC, ACB, BAC, BCA, CBA, CAB) of the following three drugs: Naproxen 500 mg tablets twice daily (BID), Meloxicam 7.5 mg tablets BID and Celecoxib 200 mg capsules BID. After these 3 initial treatment sessions, participants are then randomized to the 2 best-performing drugs for 2 additional treatment sessions \[randomized to either alphabetical order (A then B) or reverse alphabetical order (B then A)\] There will be no washout periods. All 3 medications will be over-encapsulated in identical opaque capsules. arm 2: Each participant will be randomized to a different initial drug sequence (6 possibilities: ABC, ACB, BAC, BCA, CBA, CAB) of the following three drugs: Naproxen 500 mg tablets twice daily (BID), Meloxicam 7.5 mg tablets BID and Celecoxib 200 mg capsules BID. After these 3 initial treatment sessions, participants are then randomized to the 2 best-performing drugs for 2 additional treatment sessions \[randomized to either alphabetical order (A then B) or reverse alphabetical order (B then A)\] There will be no washout periods. All 3 medications will be over-encapsulated in identical opaque capsules. arm 3: Each participant will be randomized to a different initial drug sequence (6 possibilities: ABC, ACB, BAC, BCA, CBA, CAB) of the following three drugs: Naproxen 500 mg tablets twice daily (BID), Meloxicam 7.5 mg tablets BID and Celecoxib 200 mg capsules BID. After these 3 initial treatment sessions, participants are then randomized to the 2 best-performing drugs for 2 additional treatment sessions \[randomized to either alphabetical order (A then B) or reverse alphabetical order (B then A)\] There will be no washout periods. All 3 medications will be over-encapsulated in identical opaque capsules. arm 4: Each participant will be randomized to a different initial drug sequence (6 possibilities: ABC, ACB, BAC, BCA, CBA, CAB) of the following three drugs: Naproxen 500 mg tablets twice daily (BID), Meloxicam 7.5 mg tablets BID and Celecoxib 200 mg capsules BID. After these 3 initial treatment sessions, participants are then randomized to the 2 best-performing drugs for 2 additional treatment sessions \[randomized to either alphabetical order (A then B) or reverse alphabetical order (B then A)\] There will be no washout periods. All 3 medications will be over-encapsulated in identical opaque capsules. arm 5: Each participant will be randomized to a different initial drug sequence (6 possibilities: ABC, ACB, BAC, BCA, CBA, CAB) of the following three drugs: Naproxen 500 mg tablets twice daily (BID), Meloxicam 7.5 mg tablets BID and Celecoxib 200 mg capsules BID. After these 3 initial treatment sessions, participants are then randomized to the 2 best-performing drugs for 2 additional treatment sessions \[randomized to either alphabetical order (A then B) or reverse alphabetical order (B then A)\] There will be no washout periods. All 3 medications will be over-encapsulated in identical opaque capsules. arm 6: Each participant will be randomized to a different initial drug sequence (6 possibilities: ABC, ACB, BAC, BCA, CBA, CAB) of the following three drugs: Naproxen 500 mg tablets twice daily (BID), Meloxicam 7.5 mg tablets BID and Celecoxib 200 mg capsules BID. After these 3 initial treatment sessions, participants are then randomized to the 2 best-performing drugs for 2 additional treatment sessions \[randomized to either alphabetical order (A then B) or reverse alphabetical order (B then A)\] There will be no washout periods. All 3 medications will be over-encapsulated in identical opaque capsules. arm 7: Each participant will be randomized to a different initial drug sequence (6 possibilities: ABC, ACB, BAC, BCA, CBA, CAB) of the following three drugs: Naproxen 500 mg tablets twice daily (BID), Meloxicam 7.5 mg tablets BID and Celecoxib 200 mg capsules BID. After these 3 initial treatment sessions, participants are then randomized to the 2 best-performing drugs for 2 additional treatment sessions \[randomized to either alphabetical order (A then B) or reverse alphabetical order (B then A)\] There will be no washout periods. All 3 medications will be over-encapsulated in identical opaque capsules. arm 8: Each participant will be randomized to a different initial drug sequence (6 possibilities: ABC, Each participant will be randomized to a different initial drug sequence (6 possibilities: ABC, ACB, BAC, BCA, CBA, CAB) of the following three drugs: Naproxen 500 mg tablets twice daily (BID), Meloxicam 7.5 mg tablets BID and Celecoxib 200 mg capsules BID. After these 3 initial treatment sessions, participants are then randomized to the 2 best-performing drugs for 2 additional treatment sessions \[randomized to either alphabetical order (A then B) or reverse alphabetical order (B then A)\] There will be no washout periods. All 3 medications will be over-encapsulated in identical opaque capsules. arm 9: Each participant will be randomized to a different initial drug sequence (6 possibilities: ABC, ACB, BAC, BCA, CBA, CAB) of the following three drugs: Naproxen 500 mg tablets twice daily (BID), Meloxicam 7.5 mg tablets BID and Celecoxib 200 mg capsules BID. After these 3 initial treatment sessions, participants are then randomized to the 2 best-performing drugs for 2 additional treatment sessions \[randomized to either alphabetical order (A then B) or reverse alphabetical order (B then A)\] There will be no washout periods. All 3 medications will be over-encapsulated in identical opaque capsules. arm 10: Each participant will be randomized to a different initial drug sequence (6 possibilities: ABC, ACB, BAC, BCA, CBA, CAB) of the following three drugs: Naproxen 500 mg tablets twice daily (BID), Meloxicam 7.5 mg tablets BID and Celecoxib 200 mg capsules BID. After these 3 initial treatment sessions, participants are then randomized to the 2 best-performing drugs for 2 additional treatment sessions \[randomized to either alphabetical order (A then B) or reverse alphabetical order (B then A)\] There will be no washout periods. All 3 medications will be over-encapsulated in identical opaque capsules. arm 11: Each participant will be randomized to a different initial drug sequence (6 possibilities: ABC, ACB, BAC, BCA, CBA, CAB) of the following three drugs: Naproxen 500 mg tablets twice daily (BID), Meloxicam 7.5 mg tablets BID and Celecoxib 200 mg capsules BID. After these 3 initial treatment sessions, participants are then randomized to the 2 best-performing drugs for 2 additional treatment sessions \[randomized to either alphabetical order (A then B) or reverse alphabetical order (B then A)\] There will be no washout periods. All 3 medications will be over-encapsulated in identical opaque capsules. arm 12: Each participant will be randomized to a different initial drug sequence (6 possibilities: ABC, ACB, BAC, BCA, CBA, CAB) of the following three drugs: Naproxen 500 mg tablets twice daily (BID), Meloxicam 7.5 mg tablets BID and Celecoxib 200 mg capsules BID. After these 3 initial treatment sessions, participants are then randomized to the 2 best-performing drugs for 2 additional treatment sessions \[randomized to either alphabetical order (A then B) or reverse alphabetical order (B then A)\] There will be no washout periods. All 3 medications will be over-encapsulated in identical opaque capsules.
Interventions: intervention 1: Celecoxib intervention 2: Naproxen intervention 3: Meloxicam
Intervention descriptions: intervention 1: Celecoxib 200 mg capsules twice daily (BID) All 3 medications will be over-encapsulated in identical opaque capsules intervention 2: Naproxen 500 mg tablets twice daily (BID) All 3 medications will be over-encapsulated in identical opaque capsules intervention 3: Meloxicam 7.5 mg tablets twice daily (BID) All 3 medications will be over-encapsulated in identical opaque capsules

Protocol documents:
Prot_SAP_000.pdf: 
IRB NUMBER: HSC-MS-19-0677 
IRB APPROVAL DATE: 049/161/202119 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Individualizing Anti-Inflammatory Medications for Adults with Axial Spondyloarthritis: 
A series of N- of 1 trials 
 
NCT 04115098 
 
Version Date: 04/16/2021 
 
 


IRB NUMBER: HSC-MS-19-0677 
IRB APPROVAL DATE: 049/161/202119 
 
AxSpA-N1-NSAIDs 
 
 
Individualizing Anti-Inflammatory Medications for 
Adults with Axial Spondyloarthritis: A series of N- 
of 1 trials 
 
 
Principal Investigator 
Mark Hwang, MD 
 
Collaborators 
John Reveille, MD 
Charles Green, PhD 
Jon Tyson, MD 
Joyce Samuel, MD 
Shervin Assassi, MD 
 
 
Study Coordinator 
Reyna Chavez 
Benjamin Naovarat 
 
 
Version Number: 3.3 
Version Date: April 1, 2021 


IRB NUMBER: HSC-MS-19-0677 
  
IRB APPROVAL DATE: 094/116/201291 
Protocol Version 3.3 Date: 01-April-2021 
Page 2 of 7 
 
1. 
BACKGROUND AND RATIONALE 
Ankylosing spondylitis (AS) is a disease characterized by chronic, inflammatory back pain 
and radiographic disease of the axial spine with an estimated prevalence of 0.2 to 0.5% 
in the United States population (1, 2). AS is now recognized an important subset of the 
broader and more prevalent diagnosis of axial spondyloarthritis (AxSpA) that is estimated 
to be up to 1.4% of the adult population, similar to the rheumatoid arthritis (RA) prevalence. 
This new definition of this disease has led to earlier diagnosis, with MRI imaging identifying 
a different phenotype of AxSpA patients with disease that do not develop AS (3). In 
contrast to other inflammatory rheumatic diseases, including RA, the therapeutic options 
for AxSpA are limited and confined to nonsteroidal anti-inflammatory drugs (NSAIDs) and, 
if this treatment fails, to biologic medications such as tumor necrosis factor and interleukin- 
17a blockers 
 
1.1. 
General Introduction 
Current consensus guidelines from major rheumatology professional organizations 
including the American College of Rheumatology/ Spondyloarthritis Association of 
America/ Spondyloarthritis Research and Treatment Network (SPARTAN) and the 
European League against Rheumatism (EULAR) recommend NSAIDs (as a class) as the 
first-line drug treatment for patients with symptomatic disease in AxSpA(7-9). Furthermore, 
the same guideline statements have suggested continuous over on-demand NSAID 
treatment for active AxSpA. Opioid medications are strongly discouraged as they do not 
effectively treat AS/AxSpA. US claims databases however show a 27.3-76.7% prevalence 
of chronic opioid use among AxSpA patients(10). 
 
1.2. 
Rationale and justification for the Study 
In the past, phenylbutazone (FDA-approved in 1946) was considered the NSAID of choice 
for the treatment of AS, but it was supplanted by NSAIDs without similar risk of bone 
marrow suppression. Indomethacin was then favored as an effective NSAID in AS 
patients, despite the lack of randomized controlled trials (RCTs) demonstrating superior 
efficacy(11). More recently, cyclooxygenase-2 (COX-2) selective inhibitors, such as 
celecoxib and etoricoxib, have shown similar efficacy in AS to non-selective NSAIDs(12, 
13). At this time, 11 NSAIDs are approved for the treatment of AS in Europe and 5 in the 
United States; additional NSAIDs are approved for other indications and are available for 
use. The question that naturally arises when there are many treatment options is whether 
any specific NSAID is more effective as well as if the benefits of pharmacologic treatment 
justify the potential short and long-term associated hazards. 
 
While recent Bayesian network meta-analysis have suggested that etoricoxib may be 
superior compared to other NSAIDs in terms of Visual Analog Scale (VAS) pain reduction 
in pairwise comparisons (14), it remains unanswered if any NSAID is superior in terms of 
overall disease activity that also includes important disease domains such as stiffness, 
fatigue, 
peripheral 
arthritis/enthesitis(inflammation 
of 
the 
ligamentous/tendinous 
attachments) in addition to spinal pain. Furthermore, etoricoxib is not FDA-approved for 
any indication due to cardiovascular safety concerns. It remains unknown thus if one 
NSAID therapy is superior to others in the clinical care of AxSpA patients. 


IRB NUMBER: HSC-MS-19-0677 
  
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Protocol Version 3.3 Date: 01-April-2021 
Page 3 of 7 
 
2. 
HYPOTHESIS, OBJECTIVES, and OUTCOME MEASURES 
 
2.1. 
Hypothesis and Objectives 
Aim 1: To compare selective (COX-2) and nonselective COX inhibitors with respect to the 
extent to which disease activity (as assessed by ASDAS) is improved without self- 
reported, unacceptable side effects among individual patients with AxSpA through n-of-1 
series of trials. 
Hypothesis. Compared to nonselective COX inhibitors (naproxen and meloxicam), 
celecoxib will be the preferred medication based on short term responses for a majority 
(>50%) of patients. 
 
SubAim 1A: To assess the effort required for the n-of-1 trials, the acceptability, and 
proportion of patients who complete the n-of-1 trials. 
Hypothesis: Patients complete the n-of-1 trial will demonstrate >80% acceptability and 
completion of this N-of-1 trial. 
 
Aim 2. To compare selective (COX-2) and nonselective COX inhibitors impact on Health- 
related Quality of Life (HrQOL) as assessed through standard gamble (SG) utility 
assessment and how this relates to changes in disease activity. 
Hypothesis: COX-2 NSAIDS will result in higher utilities, which will strongly correlate with 
changes in ASDAS scores. 
 
Aim 3: To conduct proteomic assessment of predictive biomarkers of NSAID response. 
Hypothesis: Patients will demonstrate candidate serum biomarkers predictive of disease 
remission due to NSAID use (response = ASDAS <1.3 on any NSAIDs treatment) 
 
We expect at the end of these experiments, we will potentially be able to understand the 
differences in individual NSAID on disease activity, HrQoL as well as generate preliminary 
data that will identify patients more likely to respond to NSAIDs treatment a priori. This 
may allow us to change the current paradigm in AS pharmacotherapy by individualizing 
NSAIDs usage, decreasing opioid usage and improving health outcomes for AxSpA 
patients. 
 
2.2. 
Outcome Measures 
 
a. 
Primary Outcome Measure(s) 
The primary outcome of this study will be the Ankylosing Spondylitis Disease Activity 
Score (ASDAS). Please see Trial Schedule for time point assessment. 
 
b. 
Secondary Outcome Measure(s) 
Secondary outcomes include the Standard Gamble, Patient-Information Measurement 
Information System (PROMIS-29), Bath Ankylosing Spondylitis Functional Index 
(BASFI), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath 
Ankylosing Spondylitis Metrology Index (BASMI), Visual Analog Scale-Pain (VAS- 
Pain), Visual Analog Scale-Global VAS-Global. 
 
STUDY POPULATION 
 
Adults >18 years of age who fulfill ASAS classification criteria fox AxSpA and/or modified 
New York classification criteria for AS(22, 23) with active disease, defined as ASDAS ≥ 
2.1 (24) to capture the spectrum of patients with this disease. Patients who are anticipated 


IRB NUMBER: HSC-MS-19-0677 
  
IRB APPROVAL DATE: 094/116/201291 
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Page 4 of 7 
 
to undergo biologic medication initiation/switching during the trial period (concurrent, 
stable biologic medication use is acceptable) will be excluded. 
. 
Inclusion Criteria: 
1. Patients must meet modified New York Classification and/or Assessment of 
Spondyloarthritis International Society (ASAS) criteria for Classification Criteria for 
AxSpA 
Ankylosing Spondylitis Disease Activity Score ≥ 2.1 or taking continuous NSAIDs (defined as an 
NSAID equivalence score of >=50% over the past 6 months). 
 
 
Exclusion Criteria: 
1. Changing background biologic/disease modifying-rheumatic medications within < 3 
months. 
2. Opioid medication use 
3. Current or expected pregnancy 
4. History of cardiovascular disease (previous stroke, myocardial infarction, or 
percutaneous intervention. 
5. End stage liver disease 
6. Chronic Kidney Disease > Stage IIIb 
 
3. 
TRIAL SCHEDULE 
 
Baseline 
Visit 
(Week 1) 
Visit 1 
(Week 5) 
Visit 2 
(Week 9) 
Visit 3 
(Week 
13) 
Visit 4 
(Week 
17) 
Visit 5 
(Week 
21) 
Visit 6* 
(Week 
25) 
Visit 7* 
(Week 
29) 
Informed Consent 
Yes 
No 
no 
no 
no 
no 
no 
no 
Medical History 
yes 
yes 
yes 
yes 
yes 
yes 
yes 
yes 
Physical Exam 
yes 
yes 
yes 
yes 
yes 
yes 
yes 
yes 
ASDAS 
yes 
yes 
yes 
yes 
yes 
yes 
yes 
yes 
Standard Gamble 
yes 
yes 
yes 
yes 
yes 
yes 
yes 
yes 
PROMIS-29 
yes 
yes 
yes 
yes 
yes 
yes 
yes 
yes 
BASFI 
yes 
yes 
yes 
yes 
yes 
yes 
yes 
yes 
BASDAI 
yes 
yes 
yes 
yes 
yes 
yes 
yes 
yes 
BASMI 
yes 
yes 
yes 
yes 
yes 
yes 
yes 
yes 
VAS-Pain 
yes 
yes 
yes 
yes 
yes 
yes 
yes 
yes 
VAS-Global 
yes 
yes 
yes 
yes 
yes 
yes 
yes 
yes 
LAB: Complete Blood 
Count (5 cc) 
yes 
no 
no 
no 
no 
no 
no 
no 
LAB: C-Reactive 
Protein (5 cc) 
yes 
yes 
yes 
yes 
yes 
yes 
yes 
yes 
LAB: Complete 
Metabolic Panel (5 cc) 
yes 
no 
no 
no 
no 
no 
no 
no 
Baseline Serum Blood 
Draw (10 cc) 
Yes 
no 
no 
no 
no 
no 
no 
no 
Medication Given 
yes 
yes 
yes 
yes 
yes 
no 
yes 
no 
Adverse Events 
yes 
yes 
yes 
yes 
yes 
yes 
yes 
yes 
Concomittant 
Medication Screen 
yes 
yes 
yes 
yes 
yes 
yes 
yes 
yes 
*Each consecutive visit will be 4 weeks apart starting at Baseline visit (Week 1), Visit 1 (week 5) and continuing in this pattern. 


IRB NUMBER: HSC-MS-19-0677 
  
IRB APPROVAL DATE: 094/116/201291 
Protocol Version 3.3 Date: 01-April-2021 
Page 5 of 7 
 
Baseline Visit 
Cycle 1 
Eliminate drug with unacceptable side effects or smallest change from baseline ASDAS 
Cycle 2 
Eliminate drug with unacceptable side effects or smallest change from baseline ASDAS 
N-of-1 trial complete 
Drug A:  Weeks 13-16 on therapy 
Drug B: Weeks 17-20 on therapy 
Drug A:  Weeks 1-4 on therapy 
Drug B:   Weeks 5-8 on therapy 
Drug C: Weeks 9-12 on therapy 
Establish baseline Ankylosing Spondylitis Disease Activity Score (ASDAS). Confirm need for 
pharmacotherapy and previous medication exposures 
4. 
STUDY DESIGN 
 
Allocation will occur through REDCap with each participant randomized to a different initial 
drug sequence (6 possibilities: ABC, ACB, BAC, BCA, CBA, CAB) of the following three 
drugs: Naproxen 500 mg tablets twice daily (BID), Meloxicam 7.5 mg tablets BID and 
Celecoxib 200 mg capsules BID. Patients will be randomized in blocks of 6 to ensure that 
no drug is assigned to be the first drug tested more often than the others. Medications will 
be obtained by the investigation team, and then all 3 medications will be over- 
encapsulated in identical opaque capsules. 4 weeks worth of medication will be given out 
in barcoded, plastic bottles at each monthly visit to ensure double blinding to both patients 
and researchers. 
 
Baseline disease activity is defined as ASDAS-CRP scores (Figure 1) with a one-week 
washout period off of pharmacotherapy. Treatments will be prescribed at random order 
through REDCAP randomization at full-dose without washout periods to maximize patient 
comfort and acceptability and avoid increasing disease actively, Moreover, residual effects 
will likely no longer be present by the end of the 4th week on the next medication when 
ASDAS and direct utility assessment (Study 2) are assessed. 
 
Cycle 1 is defined as the initial 12 weeks of treatment periods, during which the three 
options are each assessed at a 4-week period (Figure 3). At the clinic visit marking the 
end of cycle 1, the patient and physician will discuss the comparative effectiveness and 
self-reported 
tolerability 
(specifically 
screening 
by 
cardiovascular, 
renal 
and 
gastrointestinal Review of Symptoms) of each of the tested options. Patients and 
Investigators will be blinded to reduce potential biases regarding different treatments. The 
drug that produces either an unacceptable side effect or the smallest decrease in disease 
activity will be removed from consideration. The remaining two drugs will be repeated for 
4-week treatments (Cycle 2) in random order to confirm which drug yields the >reduction 
in disease activity without unacceptable side effects. We will repeat Cycle 2 if drugs cannot 
be differentiated. 
 
Figure 3. N-of-1 clinical trial schema 


IRB NUMBER: HSC-MS-19-0677 
  
IRB APPROVAL DATE: 094/116/201291 
Protocol Version 3.3 Date: 01-April-2021 
Page 6 of 7 
 
We will collect baseline serum samples in AxSpA patients (N=50). Olink® proteomics 
use DNA-coupled methods, (paired oligonucleotide binding) of antibodies with unique 
DNA reports (n=92) allow scaled multiplexing of candidate proteins. We will test the olink 
inflammation panel of 92 candidate proteins previously indicated in 45 inflammatory 
diseases. The performance of all tested proteins will be compared to current laboratory 
yardsticks (e.g. CRP). All candidate proteins will be tested in univariate modeling with 
student’s t-test to look for differences between responders and non-responders. Non- 
normal data distributions will under log-transformation for comparisons. 
 
5. 
SAFETY MEASUREMENTS 
NSAIDs are FDA approved for various forms of arthritis and chronic pain, They are known 
disease-modifying drugs in AS. Adverse gastrointestinal events have been noted in clinical 
trials and post-marketing data including gastritis, bleeding, ulceration and perforation. 
Rofecoxib, a COX- 2 inhibitor, previously marketed under the label of VioxxTM was pulled 
from the market by the FDA in 2004 due to increased cardiac events including myocardial 
infarction. A recent clinical trial comparing low dose celecoxib compared to moderate dose 
naproxen and ibuprofen did not demonstrate increased vascular suggesting this may not 
be a unique risk with selective NSAIDs (36). Thus, subjects are not exposed to any 
additional exposures when compared to routine care. 
 
6. 
DATA ANALYSIS 
All data will be collected utilizing a standardized case report form and entered into a 
REDCap™ database. Each subject will be assigned a study-specific number. Patients will 
be randomly assigned and data will be directly inputted by patients into the REDCap 
collected from standard AS-specific Patient Reported Outcome questionnaires with clinic- 
use-only touchpads. 
 
Data collected will include: demographics, disease duration, laboratory values, and 
patient-reported outcome/quality of life questionnaires completed at the time of enrollment 
and up to one year post enrollment. Study coordinators will check for completeness of 
patient forms at the time of their visits. Each item inputted directly to REDCap will have 
validity checks performed to ensure data entered are accurate and that items are not 
skipped during entry by mistakes by the investigator team. 
 
Any data that is deemed “missing” will be dropped from the study unless patients are re- 
contacted for adjuration within 24 hours by the study coordinators. A sensitivity analysis 
will be performed including those that were potentially dropped due to missing data 
 
7. 
SAMPLE SIZE AND STATISTICAL METHODS 
The data analytic strategy will use generalized linear multilevel modeling to account for 
clustering of participants with repeated observations. Modeling will use R v. 3.4 and Stan 
v. 1.10.(28, 29) Initial analyses examining group differences for baseline variables will use 
cross-tabulation, ANOVA’s, and examination of correlations between baseline variables 
and specified outcomes. For the purposes of evaluating the comparability of groups, a 
posterior probability of > 95% will constitute evidence for statistically reliable differences. 
Baseline or demographic variables on which group differences are detected, and which 
are correlated with outcomes, meet the definition of confounders (30) and will result in two 
sets of analyses: one in which the relevant variable is included as a covariate and one in 
which it is not. This will permit determination of the degree to which any group differences 
might confound conclusions regarding treatment. All analyses will be conducted on an 
intention-to-treat basis. Bayesian approaches will implement joint modeling of observed 
outcomes and missing data, which is robust to ignorable missingness (i.e., MCAR and 
MAR) (31). Sensitivity analyses will evaluate robustness of analytic conclusions to missing 


IRB NUMBER: HSC-MS-19-0677 
  
IRB APPROVAL DATE: 094/116/201291 
Protocol Version 3.3 Date: 01-April-2021 
Page 7 of 7 
 
data. Non-ignorable missing data patterns will be addressed through pattern-mixture 
modeling methods (32). Convergence of Bayesian analyses on the posterior distributions 
via Monte-Carlo Markov chain (MCMC) will be assessed via graphical (Gelman-Rubin 
Plots) and quantitative (Gelman-Rubin Diagnostics and Effective Sample Size) evidence. 
Evaluation of posterior distributions will permit statements regarding the probability that 
effects of varying magnitudes exist, given the data. Specification of diffuse, neutral priors 
will reflect the initial uncertainty regarding effect sizes. For all generalized linear multilevel 
models, priors for regression coefficients will be specified as ~Normal (µ=0, σ2=100) on 
the identity or log-scale depending upon the model, level one error variances will be 
specified as ~Half-T (df = 3, mean = 0, standard deviation = 100). Prior distributions for 
level two variances will use ~Half-T (df = 3, mean = 0, standard deviation = 100). Priors 
for the comparison of proportions will be specified as ~Beta (α=0.5, β=0.5). To the degree 
possible we will also evaluate informative priors based on the previous literature data. Pre- 
specified post-hoc sub-group analyses will include comparing patients with: baseline high 
disease activity, modified New York Criteria for AS. 
 
8. 
ETHICAL CONSIDERATIONS 
Risks to Subjects 
NSAIDs are FDA approved for various forms of arthritis and chronic pain, They are known 
disease-modifying drugs in AS. Adverse gastrointestinal events have been noted in clinical 
trials and post-marketing data including gastritis, bleeding, ulceration and perforation. 
Rofecoxib, a COX- 2 inhibitor, previously marketed under the label of VioxxTM was pulled 
from the market by the FDA in 2004 due to increased cardiac events including myocardial 
infarction. A recent clinical trial comparing low dose celecoxib compared to moderate dose 
naproxen and ibuprofen did not demonstrate increased vascular suggesting this may not 
be a unique risk with selective NSAIDs (36). Thus, subjects are not exposed to any 
additional exposures when compared to routine care. 
 
Protection against risks 
The two main complications associated with NSAIDs are cardiac events and 
gastrointestinal bleeding. These estimates are unknown this patient population in part from 
the juxtaposed concepts of inflammation reduction leading to less cardiac events in 
rheumatic diseases vs. coronary vasospasm from COX inhibition with retrospective, 
observation studies conflicting in directionality of events. COX-2 inhibitors are thought to 
have less gastrointestinal events than nonselective NSAIDs. 
 
 
9. 
PUBLICATIONS 
We believe these studies will be impactful and of high interest to AxSpA patients and 
rheumatologists. We will submit our findings for presentation at planned international 
rheumatology meetings of SPARTAN, ACR and EULAR. We will plan to submit 
manuscripts to rheumatology journals ensuring dissemination of the work planned.