This study aims to compare the effectiveness of SAR302503-Ruxolitinib combination therapy versus Ruxolitinib monotherapy in reducing disease burden in patients with myelofibrosis who have the JAK2-V617F mutation. The primary objective is to compare the therapies' ability to decrease mutant allele burden. Secondary objectives include comparing effects on bone marrow fibrosis, spleen size, cytokine levels, and blood counts. The study is a 24-month randomized controlled trial that will assess these outcomes to determine if the combination therapy provides superior clinical benefit over Ruxolitinib alone.

1. 1
Comparing the effect of SAR302503-Ruxolitinib combination therapy and Ruxolitinib
monotherapy on reducing disease burden in patients with Jak2-V617F-positive
myelofibrosis
9-20-2012
Investigator: Jacqueline Sayyah
Department of Pharmacology
University of California, San Diego
Timelines:
Date of study initiation: April 25, 2013
Date of enrollment completion: October 20, 2013
Date of last patient follow-up: April 25, 2015

2. 2
TABLE OF CONTENTS
SECTION PAGE
1. OBJECTIVES-------------------------------------------------------------------------------------------------3
1.1 PRIMARY OBJECTIVES----------------------------------------------------------------------------------3
1.2 SECONDARY OBJECTIVES-----------------------------------------------------------------------------3
2.0 HYPOTHESIS------------------------------------------------------------------------------------------------3
2.1 PRIMARY HYPOTHESIS----------------------------------------------------------------------------------3
2.2 SECONDARY HYPOTHESIS----------------------------------------------------------------------------3
3.0 BACKGROUND---------------------------------------------------------------------------------------------4
3.1 DEFINITION--------------------------------------------------------------------------------------------------4
3.2 HYDROXYUREA--------------------------------------------------------------------------------------------4
RUXOLITINIB-----------------------------------------------------------------------------------------------------5
SAR302503--------------------------------------------------------------------------------------------------------6
3.3 PRIMARY OUTCOME MEASURE----------------------------------------------------------------------6
3.4 EXPECTED RESULTS AND SIGNIFICANCE-------------------------------------------------------6
4.0 OVERVIEW OF STUDY DESIGN-----------------------------------------------------------------------7
4.1 OVERALL DESIGN-----------------------------------------------------------------------------------------7
4.2 GRAPHICAL SCHEMA OF STUDY--------------------------------------------------------------------7
SCREENING AND BASELINE ASSESSMENT PERIOD----------------------------------------------8
STUDY PERIOD--------------------------------------------------------------------------------------------------8
5.0 STUDY POPULATION-------------------------------------------------------------------------------------9
5.1 TARGET AND STUDY POPULATION-----------------------------------------------------------------9
5.2 INCLUSION CRITERIA------------------------------------------------------------------------------------9
5.3 EXCLUSION CRITERIA-----------------------------------------------------------------------------------9
RECRUITMENT AND RETENTION STRATEGY--------------------------------------------------------9
6.0 STUDY PROCEDURES, MEASUREMENTS, AND MONITORING--------------------------10
6.1 DETAILS OF INTERVENTION-------------------------------------------------------------------------10
6.2 SCHEDULE OF ASSESSMENTS---------------------------------------------------------------------10
6.3 OUTCOMES------------------------------------------------------------------------------------------------11
6.3A PRIMARY OUTCOME MEASURES----------------------------------------------------------------11
6.3A SECONDARY OUTCOME MEASURES-----------------------------------------------------------11
QUALITY CONTROL-------------------------------------------------------------------------------------------12
6.3B SAFETY AND TOXICITY MEASURES-------------------------------------------------------------12
6.4 MONITORING PLANS FOR SAFETY----------------------------------------------------------------13
INFORMED CONSENT---------------------------------------------------------------------------------------13
7.0 DATA MANAGEMENT AND ANALYSIS------------------------------------------------------------13
7.1 DATA COLLECTION PROCEDURES----------------------------------------------------------------13
7.2 ANALYSIS OF BASELINE DATA----------------------------------------------------------------------13
7.3 STATISTICAL ANALYSIS OF OUTCOMES--------------------------------------------------------14
7.4 SAMPLE SIZE AND POWER OF STUDY-----------------------------------------------------------14
8.0 REFERENCES---------------------------------------------------------------------------------------------15

3. 3
Comparing the effect of SAR302503-Ruxolitinib combination therapy and Ruxolitinib
monotherapy on reducing disease burden in patients with Jak2-V617F-positive
myelofibrosis
1. OBJECTIVES
1.1 PRIMARY OBJECTIVES
The primary purpose of this study is to compare the effectiveness of Jak2 targeted SAR302403-
Ruxolitinib combination therapy and Ruxolitinib monotherapy in reducing the Jak2V617F mutant
allele burden and hence the malignant clone in myelofibrosis patient with Jak2-V617 mutations
as assessed by allele-specific quantitative real-time PCR.
1.2 SECONDARY OBJECTIVES
To compare SAR302503-Ruxolitinib combination therapy and Ruxolitinib monotherpay for:
1. Effects in the reduction of bone marrow fibrosis in myelofibrosis patients as assessed by
histopathological analysis.
2. Effects in the reduction of spleen volume as determined by CT scan
3. Effects on reducing serum cytokine levels and blood counts as determined by ELISA and
flow cytometery, respectively.
4. To determine the safety of SAR302503 and Ruxolitinib combination therapy over a 24-month
treatment period.
2. HYPOTHESIS
2.1 PRIMARY HYPOTHESIS
SAR302503-Ruxolitinib combination therapy will decrease Jak2-V617F allele burden 15% more
than Ruxolitinib monotherapy at 24 months.
2.2 SECONDARY HYPOTHESIS
1. SAR302503-Ruxolitinib combination therapy will suppress bone marrow fibrosis 20% more
than Ruxolitinib monotherapy at 24 months.
2. SAR302503-Ruxolitinib combination therapy will decrease spleen volume 35% more than
Ruxolitinib monotherapy at 24 months.
3. SAR302503-Ruxolitinib combination therapy will reduce cytokine levels 15% more and
normalize white blood cell and platelet counts at a 10% faster rate than Ruxolitinib
monotherapy.
4. SAR302503-Ruxolitinib combination therapy will be safe in myelofibrosis patients during the
24-month treatment period.

4. 4
3.0 BACKGROUND
3.1 DEFINITION AND EPIDEMIOLOGY OF TARGET DISEASE
Myelofibrosis is a type of bone marrow disorder that results from unregulated clonal growth of
the master stem cell that produces red cells, white cells and platelets. Marked leukocytosis and
thrombocytosis occur at diagnosis (1-3). In the bone marrow of pre-fibrotic myelofibrosis
patients, overall hypercellularity includes prominent growth of abnormally differentiated
megakaryocytes. These megakaryocytes have hypolobulated, cloud like and hyperchromatic
nuclei, demonstrate dense clustering and are normally accompanied by normal granulocyte
differentiation. Due to the aberrant growth of bone marrow cells, stromal cells react by secreting
different cytokines (4-5). Abnormal cytokine expression in myelofibrosis is believed to represent
an inflammatory response and contribute to bone marrow fibrosis (6). As the disease
progresses, reticulin fibrosis increases, finally resulting in collagen fibrosis. The resulting
scarring prevents the bone marrow from producing blood cells (1-3).
In myelofibrosis, the spleen enlarges and contributes to the production of blood cells, a
compensatory process called extramedullary hematopoiesis. Abnormal blood cells can also
penetrate the spleen and liver and these organs are enlarged in about 60-80% of myelofibrosis
patients. The typical early symptoms of myelofibrosis are fatigue, decreased appetite, weight
loss, night sweating and fever. These constitutional symptoms are mediated by the abnormal
release of cytokines that include IL-2, IL-8, IFN-γ, and TNF-α. With advanced fibrosis, anemia
leads to weakness, the liver and spleen progressively enlarge and liver failure and cirrhosis and
portal hypertension can result in bleeding in the gastrointestinal tract, and finally pulmonary
hypertension and lung and cardiac failure may supervene. Most patients die from organ failure
within 5-7 years (7). About 20% of cases of mylefibrosis progress to acute myelogenous
leukemia resulting in an average patient survival after such progression of only 5 months (8).
JaK2 is a non-receptor tyrosine kinase, which phosphorylates cytoplasmic targets, including the
signal transducers and activators of transcription (STATs) that are important for cell growth and
survival. Jak2 has pivotal functions for signal transduction of a set of cytokine receptors
required in definitive erythropoiesis. In 2005, a Jak2V617F mutation in the pseudo-kinase (JH2)
domain of JaK2 was discovered (9-12). The JH2 domain of Jak2 serves as a regulatory domain,
which suppresses the activity of the kinase domain (11). Substitution of valine 617 for
phenylalanine destabilizes the inhibitory function of the JH2, resulting in increased Jak2 kinase
activity and cell survival. The Jak2-V617F mutation occurs in about 60-65% of patients with
myelofibrosis and the relationship between Jak signaling and the signs and symptoms of this
blood disorder is well established (9-12). The Jak2-V617F mutation is present in granulocytes,
erythroblasts and myoblasts and in all erythropoietin (EPO)-independent erythroid colonies (13-
14). The erythroid colonies with the Jak2-V671F mutation are able to grow in the absence of
EPO. Therefore, the Jak2-V617F mutation also results in factor-independent growth of various
hematopoietic cell lines. Other alterations such as increased Jak1 signaling, as well as Jak2
exon 12 mutations have been implicated in the etiology and symptomology of myelofibrosis
(15). The understanding of dysregulated Jak2 activity in myelofibrosis as the basic
pathophysiologic abnormality in patients with this disease has led to the clinical development of
inhibitors that target Jak2.
3.2 Hydroxyurea
Hydroxyurea (HU) is used as a first-line treatment for myelofibrosis. HU is a simple organic
compound that acts specifically on the S-phase of the cell cycle by blocking the activity of the
enzyme ribonucleoside diphosphate reductase and hence hindering the reductive conversion of

5. 5
ribonucleotides to deoxyribonucleotides (16). The end result is that DNA synthesis is inhibited.
Although HU is widely used in the treatment of myelofibrosis, there is limited published data on
its efficacy and tolerability in these patients. In a study by Lofvenverg et al., a favorable
therapeutic response in 8 out of 59 myelofibrosis patients was observed. However, moderate
toxicity was observed and 21 episodes of accentuation of anemia were registered during HU
treatment. In a retrospective study of 40 myelofibrosis patients treated with HU, bone pain
(100% of patients) and splenomegaly (40% of patients) were reduced but this drug had limited
efficacy in reducing spleen size (17). A worsening of anemia or appearance of cytopenia was
also observed (17). Furthermore, HU has not been proven to change the natural course of the
disease and there have been concerns about its possible mutagenic effect since there are a few
cases where transformation to acute leukemia has been detected in patients using this drug. In
many patients, the long-term benefit from hydroxyurea treatment is restricted because of the
progressive loss of efficacy or development of resistance to hydroxyurea. Therefore, there is a
need for more effective therapy to treat myelofibrosis.
Ruxolitinib
Deregulation of the Jak-STAT pathway is a highly prevalent aberration in patients with
myelofibrosis. In addition to the Jak2-V617F mutation, increased Jak1 signaling, as well as
Jak2 exon 12 mutations, have been implicated in the disease. Hence, the Jak-STAT signaling
pathway is an attractive drug target for the treatment of myelofibrosis.
Ruxolitinib is a potent and selective Jak1 and Jak2 inhibitor, which has been tested on
myelofibrosis patients in two separate randomized Phase III trials. In a double-blind, placebo
controlled study that included 309 patients, 41.9% of patients on Ruxolitinib (vs. 0.7% on
placebo) achieved greater than 35% reduction in spleen volume as assessed by MRI at 24
weeks. In addition, 46% of patients on Ruxolitinib (vs. 5.3% on placebo) experienced a greater
than 50% improvement in constitutional symptoms (18). In another study of 153 myelofibrosis
patients that were randomized to either best available therapy or Ruxolitinib (25 mg twice daily
dose), greater than 40% spleen volume reduction was observed by MRI in 28% of patients on
Ruxolitinib, whereas no patients on best available therapy achieved reduced splenomegaly after
48 weeks (19). In addition, constitutional symptoms were improved in greater than 50% of
patients on Ruxolitinib and there was a rapid and significant reduction in proinflammatory
cytokines. Patients mean leukocyte count after 3 months of Ruxolitinib treatment (25 mg twice-
daily) also decreased from 29.8 X109
/L to 16.0 X 109
/L (20).
Although patients on Ruxolitinib show symptomatic improvement, the drug nevertheless has
side effects. Ruxolitinib inhibits Jak1 as well as Jak2. Since Jak2 is essential for normal
hematopoiesis, it is no surprise that a side effect of this drug is thrombocytopenia and anemia,
which occurred in 20% of patients. Unfortunately, since myelofibrosis patients are already
anemic, some patients even saw a worsening of their anemia with the Jak2 inhibitor. In
addition, patients who showed symptomatic improvements did not have substantial reduction in
their Jak2-V616F mutant allele burden, suggesting that the tumor clone persisted in the
presence of Ruxolitinib (20). The drug also had little effect on reducing bone marrow fibrosis.
Furthermore, Ruxolitinib discontinuation was associated with rapid relapse of symptoms. All
together, Studies on Ruxolitinib indicate that this drug reduces symptoms associated with
myelofibrosis but has no significant effect on Jak2-V617F mutant allele burden or bone marrow
fibrosis (20). These results suggest that targeting the mutant clone with a drug could further
improve clinical outcomes.

6. 6
SAR302503
SAR302503 is a selective and potent Jak2 inhibitor and its shown to suppress the growth of
erythroid colonies in the presence of the Jak2-V617F and Jak2 exon 12 mutations and is 35 and
334 times more selective for Jak2 compared with Jak1 and Jak3, respectively (21). In a phase
2 study of 59 myelofibrosis patients, 39% of patients using a median dose of 440 mg/day of
SAR302503 had a greater than 50% reduction in spleen volume when compared to placebo
control. At least 40% of patients with night sweats, fatigue, pruritus and cough reported rapid
and durable improvement of their symptoms. In addition, a majority of patients with leukocytosis
or thrombocytosis at baseline achieved normalization of blood counts. Importantly, a significant
SAR302503-induced decrease in Jak2-V617F allele burden was observed at 6 months in Jak2-
V61F mutation-positive patients (n=51; P=0.04), in particular, in the subgroup with allele burden
greater than 20% (20-21). This decrease in mutant allele burden was sustained at 12 months.
The most common adverse events observed were nausea (3.4%), vomiting (3.4%), and
diarrhea (10.2%). Grade 3 anemia was in seen in 35% of patients. Overall, SAR302503 is well
tolerated and induces a significant reduction in disease burden and produces durable clinical
benefit in patients with myelofibrosis.
3.3 PRIMARY OUTCOME AND ITS VALIDITY, ACCURACY AND PRECISION
The primary outcome of this study is to compare the effectiveness of SAR302503-Ruxolitinib
combination therapy and Ruxolitinib monotherapy on reducing Jak2-V617F allele burden at 24
months. The Jak2-V617F mutation is a valid diagnostic marker for myelofibrosis and has been
endorsed by the World Health Organization system for the classification of myeloid
malignancies (22). The mutated allele burden is an important contributor to myelofibrosis
phenotype and homozygosity for the mutation occurs frequently in this disease. A higher Jak2-
V617F allele burden has been correlated directly and significantly with higher leukocyte count
and palpable splenomegaly, which are two clinical symptoms of the disease (23). The Jak2-
V617F allele burden is also significantly associated with inferior survival (24). Moreover,
endogenous expression of Jak2-V617F in knock-in mice is sufficient for myeloproliferative
neoplasm development that resembles myelofibrosis (25-28). Specifically, these mice suffer
from marked thrombocytosis and their spleens and marrows display myeloid hyperplasia. In
addition, most animals survive to develop bone marrow fibrosis at around 9 months of age.
Collectively, these results suggest that the Jak2-V617F mutation is positively associated with
myelofibrosis and is a good target for inhibition.
3.4 EXPECTED RESULTS AND SIGNIFICANCE
In myelofibrosis, transformed hematopoietic cells are thought to release cytokines that stimulate
bone marrow fibroblast to secrete excessive collagen, resulting in bone marrow fibrosis. Due to
a gain of function mutation in Jak2 (Jak2-V617F), Jak2 signaling is upregulated in
myeloproliferative disorders and has been implicated in the pathogenesis of myelofibrosis.
Clinical studies have shown that Ruxolitinib effectively normalizes leukocytosis and
thrombocytosis after 3 months of treatment. This drug also has anti-cytokine activity and rapidly
and significantly inhibits the inflammatory effects of myelofibrosis by reducing spleen size,
abdominal discomfort and muscle pain. However, this drug via its indirect anti-cytokine effect
does not treat the disease but only its symptoms. Since the cytokine abnormalities in
myelofibrosis are reactive in nature and therefore likely to correct with effective control of the
underlying neoplastic process, an inhibitor that would target the Jak2-V61F mutated clone and
inhibit myeloproliferative activity could have an added disease modifying effect. The Jak2
selective inhibitor, SAR302503, has been shown, in a mouse transplant myeloproliferative
disorder model; to improve survival, suppress Jak2-V617F allele burden and STAT5
phosphorylation, and decrease splenomegaly and fibrosis. In addition to effectively reducing

7. 7
spleen size, leukocytosis and thrombocytosis in MF patients, SAR302503 is reported in clinical
trials to significantly reduce mutant Jak2-expressing cells population. We hypothesize that
SAR302503 and Ruxolitinib combination therapy could further improve clinical outcomes of
myelofibrosis relative to Ruxolitinib monotherapy by suppressing Jak2-V617F mutant allele
burden, bone marrow fibrosis and more effectively reducing cytokine levels and spleen size.
SAR302503 and Ruxolitinib combination therapy could provide a more significant reduction in
disease burden in patients with myelofibrosis relative to Ruxolitinib monotherapy.
4. OVERVIEW OF STUDY DESIGN
4.1. DESIGN
This is a multicenter, prospective, randomized, double blind, two armed, parallel, active control,
phase 2 clinical trial to evaluate the effect of SAR302503-Ruxolitinib combination therapy on
Jak2-V617F mutant allele burden and bone marrow fibrosis in myelofibrosis patients who are
Jak2-V617F positive. The effect of these drugs on Jak2-V617F mutant allele burden will be
assessed via allele-specific quantitative real time PCR while bone marrow fibrosis will be
determined by immunohistochemical staining of bone marrow sections. In this study, patients
will be screened for up to 4 weeks and the double-blind treatment duration will be 24 months.
Qualified patients will undergo screening and baseline assessments before being randomly
assigned to receive either 400 mg SAR302503 plus 10 mg Ruxolitinib , or 10 mg Ruxolitinib plus
matching placebo once a day.
4.2 GRAPHICAL SCHEMA OF STUDY
Fig. 1
Screening period: Alllele specific qPCR and immunohistochemistry (1 month)
136 patients with myelofibrosis
Assess Baseline Jak2-V617F mutant allele burden, bone marrow fibrosis and
spleen volume, blood counts and cytokine levels at day 0
RANDOM ASSIGNMENT
68 MF
SAR302503 + Ruxolitinib
(400mg/d) (10mg/d)
68 MF patients
Ruxolitinib + Placebo
(10 mg/d)
End of treatment visit.
Follow-up allele specific qPCR analysis and immunohistochemistry of bone marrow
(At 24months)
Follow up every 3 months and determine Jak2-V617F mutant level ,
spleen volume, and blood counts. Assess fibrosis at months 6,12 and 24.
Determine safety

8. 8
SCREENING AND BASELINE ASSESSMENT PERIOD
During a month period, subjects will be screened for study eligibility (1) . Subjects need to meet
the diagnostic criteria for myelofibrosis and express the Jak2-V617F mutation in the peripheral
blood. The presence of the mutation will be determined by allele-specific quantitative PCR and
patients will be qualified for the study if their Jak2-V617F allele burden is greater than 20%.
Aside from determining Jak2-V617F allele burden, the following baseline measurements will be
made: Upon bone marrow histology analysis, there should be a presence of megakaryocyte
proliferation that is accompanied by either reticulin or collagen fibrosis. The megakaryocyte
changes should be accompanied by increased bone marrow hypercellularity characterized by
granulocytic proliferation. Palpable splenomegaly that extends at least 5 cm below costal
margin should be observed. White blood cell and platelet count should be greater than 11 x
109
/L and 450 x 109
/L, respectively. Finally abnormally increased cytokine levels that include IL-
2, IL-8, IFN-γ, and TNF-α will be determined. Patients will be randomized if they meet all
inclusion criteria. All subjects will be provided written informed consent that has been IRB
approved.
STUDY PERIOD
Each patient will visit the research clinical every three months over 24 months. The total
number of patient visits will be 10 times, which includes a screening visit and a follow-up visit.
Jak2-V617F allele burden, spleen volume, blood counts and cytokine levels will be measured
every three months. The effect of drugs on bone marrow cellularity and fibrosis will be
assessed on day 0, month 6, month 12 and month 24.
Fig. 2 Schedule of patient visits
Screening
(1 month)
Visit 1
Visit 1
Treatment Period
24 months
Visit 2
0 months
Visit 3
3 months
Visit 4 Visit 5 Visit 6 Visit 7 Visit 8 Visit 9 Visit 10
6 months 9 months 12 months 15 months 18 months 21 months 24 months
Intervention Group
Active Control Group
Ruxolitinib + Placebo
SAR302503 + Ruxolitinib

9. 9
5.0 STUDY POPULATION
5.1 TARGET AND STUDY POPULATION
Male or female patients with myelofibrosis between the ages of 18-75 who have tested positive
for the Jak2-V617F mutation, who have bone marrow fibrosis at study enrollment and a
palpable spleen size of greater than or equal to 5 cm below the left costal margin.
5.2 INCLUSION CRITERIA
1. Diagnosis of myelofibrosis
2. Jak2-V617F positive
3. Fibrosis in bone marrow
4. Enlarged palpable spleen, at least 5 cm below costal margin
5. Leukocyte count greater than 11 x 109
/L
6. Platelet count greater than 450 x 109
/L
7. Serum creatinine less than or equal to 2.0 mg/dL
8. Subjects are between the ages of 18 to 75.
9. Written informed consent to participate
10. Willing to comply with scheduled visits, treatment plans and laboratory assessments.
5.3 EXCLUSION CRITERIA
1. Any chemotherapy or immunosuppressive drug therapy
2. Participation in any study of an investigational agent (drug, biologic, device) within 30 days
3. Prior treatment with Jak2 inhibitors such as, CYT387, lestauritinib, or SB1518.
4. Pregnant or lactating
5. No leukemia within the past 5 years
6. Congestive heart failure, myocardial infarction or pulmonary embolism within 3 months
prior to initiation of study
7. Patients with inadequate liver or renal function
8. Active viral hepatitis or HIV
9. Other severe medical, neurological or psychiatric condition that may interfere with
informed consent, compliance and with interpretation of study results.
10. Splenectomy
11. Known hypersensitivity to any ingredients in the drug formulations
RECRUITMENT AND RETENTION STRATEGY
This multicenter trial will recruit from clinics and hospitals with hematological oncology programs
that treat patients with myelofibrosi. Clinicaltrial.gov and the Myeloproliferative Neoplasm
Foundation website will post the study.
In order to retain patients in this study, the study coordinator, hired by the principal investigator,
will call and text subjects in order to ensure that they will remember and attend required
appointments. In addition, subjects will be required to enter an activity log online so that the
date and time they took the experimental drugs will be recorded. This will help the clinical trial
run more efficiently. Subjects will also be compensated for their time/effort and will be given
$30 for each completed visit.

10. 10
6.0 STUDY PROCEDURES, MEASURMENTS, AND MONITORING
6.1. DETAILS OF INTERVENTION
Following the 1-month screening period, eligible subjects will randomly be assigned to receive
400 mg SAR302503 plus 10 mg Ruxolitinib, or 10 mg Ruxolitinib plus matching placebo orally
once daily. Medications will be taken in the afternoon following lunch and patients will be blinded
to treatment assignment. To blind the administration of medication, bottles containing
medication will be prepared and numbered prior to the visits to the clinic. The investigator will
also be blinded in that she will not be aware of treatment allocations during the course of the
study but she will monitor adherence. A pharmacist not involved in the trial will prepare
SAR302503, Ruxolitinib or placebo. Personnel not involved in the clinical study will perform
blinding and randomization.
Jak2-V617F allele burden, spleen volume, blood counts, cytokine levels will assessments will be
measured every three months. Safety of drugs will be determined monthly for the first six
months and subsequently every three months. The effect of drugs on bone marrow cellularity
and fibrosis will be assessed on day 0, month 6, 12, 18 and 24.
6.2. SCHEDULE OF ASSESSMENTS
Table 1: Study Schedule
Screening Treatment
Visit 1 2 3 4 5 6 7 8 9 10
Month -1 0 3 6 9 12 15 18 21 24
Informed consent ✓
Demographics ✓
Efficacy
Jak2-V617F allele burden ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓
Bone marrow fibrosis ✓ ✓ ✓ ✓ ✓ ✓
Spleen volume ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓
Blood counts ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓
Cytokines ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓
Safety
Vital signs ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓
Itching ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓
Night sweats ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓
Bone/muscle pain ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓
Abdominal discomfort ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓
Diarrhea ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓
Serum Lipase ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓
ALT and AST ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓
Creatinine ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓
Hematology ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓

11. 11
6.3 OUTCOMES
6.3A PRIMARY OUTCOME EFFICACY MEASURES
The primary efficacy is the change in Jak2-V617F allele burden in the granulocyte fraction of the
peripheral blood from baseline to 24 months in patients treated with SAR302503-Ruxolitinib
combination therapy. The Jak2-V617F allele burden in myelofibrosis patients is correlated
directly and significantly with increased leukocyte counts, palpable splenomegaly and is
considered a valid marker in the evaluation of myelofibrosis (24). In this study, subjects should
have a significant allele burden that is defined as greater than 20% at baseline. The Jak2-
V617F allele burden of greater than 20% at baseline is in accordance with other clinical trial
studies (21). SAR302503-Ruxolitinib combination therapy or Ruxolitinib monotherapy-induced
changes in the Jak2-V617F allele burden in the granulocyte fraction of peripheral blood will be
measured by allele-specific, quantitative real-time PCR. The use of allele specific quantitative
real-time PCR has a higher sensitivity than standard PCR sequencing in detecting mutations
and is currently the preferred mutation screening test because of its ability to quantify allele
burden, a feature with potential utility for monitoring treatment response (21,23). Using allele-
specific quantitative real-time PCR, a clinical trial on the efficacy of SAR302503 reported a 50%
decrease in Jak2-V617F allele burden in patients who at baseline had an allele burden greater
than 20% (21).
Mutant allele burden will be reported as the percentage of total Jak2 represented by Jak2-
V617F (Jak2-V617F/Jak2-V617F + Jak2 wildtype). The Jak2-V617F percentage will be
obtained from a standard curve for Jak2-V617F/total Jak2 against ΔCt (CtJak2V617F - CtJak2WT),
which will be constructed using various portions of genomic DNA from the K562 and HEL
erythroleukemia cell lines that are homozygous for wild-type and Jak2-V617F, respectively. Ct
is the relative concentration of target.
The application PCR sequencing, which is a commonly used to detect mutations, has an assay
sensitivity of around 70%. The use of allele-specific quantitative real time PCR has a 90%
ability to detect mutations and has been employed by many labs to detect the Jak2-V617F
mutation. Therefore, allele-specific PCR provides a precise and reproducible method for
detecting mutations and is currently the preferred mutation screening test because of its ability
to quantify allele burden, a feature with potential utility for monitoring treatment response.
SECONDARY OUTCOME MEASURES
Reticulin staining of the bone marrow is one measure of fibrosis (reticulin fibrosis) and is
associated with malignant diseases such as myeloproliferative disorders (29). In addition,
increased trichrome staining is a measure of collagen fibrosis and is primarily associated with
myelofibrosis (29). Numerous studies employ both reticulin and collagen staining as a measure
of fibrosis in the bone marrow. Bone marrow reticulin and collagen staining has been performed
in chronic thrombocytopenia patients to assess the effect of the thrombopoietin receptor agonist
romiplostim on bone marrow fibrosis (30). This study reported that romiplostim produced a
dose-dependent increase in bone marrow fibrosis as indicated by areas of increased collagen
fibrosis and megakaryocytes on bone marrow sections (30).
Assessment of bone marrow histology to determine fibrosis will be performed at baseline and at
6, 12 and 24 months after either SAR302503-Ruxolitinib combination or Ruxolitinib
monotherapy. Baseline and follow-up bone marrow samples will be sent to a central laboratory
for staining and assessments. A panel of expert hematologists and hematopathologists not
involved in the trial will conduct the bone marrow assessments. Bone marrow fibrosis (reticulin
and collagen) will be quantified in the bone marrow biopsy specimens obtained from

12. 12
myelofibrosis patients using the modified Bauermeister scheme, which grades the degree of
reticulin/collagen on a scale from 0-4 as follows (29): 0 (absence of fibrosis), 1 (fine fibers
detected), 2 (diffuse fine fiber networks present), 3 (diffuse fiber network with scattered coarse
fibers detected) and 4 (areas of collagen on trichrome present). The data from the study will be
available in the form of photomicrographs. Samples sent to the laboratory will be blinded with
regard to treatment group.
The efficacy of SAR302503-Ruxolitinib combination therapy or Ruxolitinib monotherapy on
reducing spleen volume will be compared. The percent change in spleen volume based on CT
Scan at the end of 3, 6 and 24 months treatment with either SAR302503-Ruxolitnib combination
or Ruxolitinib monotherapy relative baseline will be determined. The effect of these two
treatments on leukocytosis (white blood cell count) and thrombocytosis (platelet count) will be
determined every three months, up to 24 months and compared to baseline. Peripheral blood
samples will be stained with anti-CD45 antibody, which is a leukocyte surface antigen
expressed by leukocytes in peripheral blood. Blood samples obtained from patients will also be
stained with anti-CD41 antibody which detects platelets. A flow cytometer will be used to
analyze and count the number of leukocytes and platelets in the patient’s blood (31). A white
blood cell count greater than 11 x 109
/L is defined as leukocytosis while a platelet count of 450 x
109
/L is considered thrombocytosis (20). Pro-inflammatory cytokine levels will measured using
multiplexed sandwich ELISA as described (21).
Quality Control
A member of the research team will be assigned as the quality control coordinator who will be
responsible for applying appropriate quality control for all aspects of the study, including
supervising staff training and certification. All research associates involved in study should
receive appropriate training in their area of specialty, which includes allele-specific PCR, CT
Scan, and immunohistochemistry or flow cytometry before the study begins. Research
associates should also be certified to show competence with regard to key procedures and
measurements. When a patient blood sample is sent for Jak2-V617F mutation analysis, a
blinded duplicate or a second specimen from a random participant will also be sent for analysis.
This strategy will give a measure of the precision of allele specific quantitative real time PCR.
The assessment of tabulated data could give clues to the presence of inaccurate or imprecise
measurements. For example, a big difference in the recorded Jak2-V617F mutation level for a
particular patient by two different research associates could indicate an error or discrepancy in
their technique.
6.3B SAFETY AND TOXICITY MEASURES
The effect of SAR302503 and Ruxolitinib combination therapy on clinically significant adverse
events will be determined every month for the first 6 months and subsequently every 3 months
for the duration of the study. The safety of drugs will be assessed by asking patients to fill a
questionnaire where they will report the severity and duration of any itching, night sweats,
bone/muscle pain, abdominal discomfort and diarrhea they experienced. The presence and
severity of these symptoms will be scored on an 11-point scale. Symptoms will be categorized
as absent (score = 0), mild (score = 1 to 3), moderate (score = 4 to 7), or severe (score = 8 to
10). The total symptom score, which will be the sum of scores for each of the above symptoms,
will be tabulated. Any hematologic adverse event such as anemia, thrombocytopenia or
neutropenia will also be recorded. Other adverse events that will be reported are abnormal
serum lipase, ALT and AST or creatinine levels, which could reveal pancreatic toxicity,
hepatotoxity and nephrotoxicity, respectively.

13. 13
6.4 MONITORING PLANS FOR SAFETY
Principal investigator should seek information on any adverse events occurring during the
clinical trial and information on all adverse events should be recorded immediately. To ensure
patient safety and reliable data, the investigator will keep records of laboratory tests and clinical
notes as original source documents for the study. The principal investigator will assign a Data
and Safety Monitoring Board (DSMB) and ensure that the DSMB will be given access to all data
and clinical study documents. The DSMB, which consists of clinical research experts with no
conflict of interest, will review data, confirm that data recorded on Clinical Research Forms is
accurate, determine whether protocol requirements and investigator’s obligations are being
fulfilled and ensure that subjects are not exposed to undue risks. The DSMB will have the right
to terminate the study if the data provide convincing evidence harm for patients. The principal
investigator will be responsible for ensuring that the DSMB will meet every three months or as
needed during the 24-month study.
INFORMED CONSENT
Patients will be given ongoing explanations that will help them make educated decisions about
whether to begin or continue participating in the trial. The research team will discuss the trial’s
purpose, procedures, risks and potential benefit with each patient. If patient decides to
participate in trial, the team will continue to update the patient on any new information that may
affect his or her situation. Furthermore, before, during, and even after the trial, the patient will
have the opportunity to ask questions and raise concerns.
7.0 DATA MANAGEMENT AND ANAYLYSIS
7.1 DATA COLLECTION PROCEDURES
The investigator will be responsible for designing the forms for recording measurements,
maintaining accuracy of all clinical and laboratory data entered on Clinical Report Forms (CRF),
choosing the computer software program used for data editing and designing the data editing
parameters for missing or erroneous entries.
Patients will complete enrollment forms for the clinical study after the screening period, at week
0. These forms will be filed in the respective patient binders and copies will be sent to the Data
Management Center (DMC). The principal investigator or study coordinators will complete the
Clinical Report Forms during each patient visit at the clinic and the completed copies will be
sent via certified mail the DMC each month. An electronic copy of Patients lab results will also
be sent to the DMC.
Quality Control for Data Management
A member of the research team will be assigned to check forms for completeness before the
patient leaves the clinic. Specifically, potential errors in ID number and name codes will be
noted. It will also be important to check whether key variable such as age and birth date are
consistent with each other. The Data Management Center will notify clinical study sites of any
inconsistent or missing information. A data entry management program will be used to flag any
missing, inconsistent or out-of-range values and attempts will be made to obtain any missing or
inaccurate data within a reasonable time frame.
7.2 ANAYLYSIS OF BASELINE DATA
The effect of SAR302503-Ruxolitinib combination therapy or Ruxolitinib monotherapy on
baseline Jak2-V617F allele burden, bone marrow fibrosis and cytokine levels will be determined
and data will be analyzed using a t-test. Data obtained from the effects of drugs on the
normalization of white blood and platelet counts will be analyzed by chi-square test.

14. 14
7.3 STATISTICAL ANALYSIS OF OUTCOMES
The primary endpoint of this study is to determine whether there is a statistically significant
difference between SAR302503-Ruxolitinib combination therapy and Ruxolitinib monotherpay in
the change in Jak2-V617F allele burden from baseline to 24 months. We will use a paired t-test
in order to determine whether the difference in SAR302503-Ruxolitinib combination and the
active control in the change in Jak2-V617F allele burden are statistically significant. The paired
t-test will also be performed to determine whether there is a statistically significant difference in
spleen volume and bone marrow fibrosis between SAR302503-Ruxolitinib combination therapy
and Ruxolitinib monotherapy. Continuous outcome variables such as spleen volume and bone
marrow fibrosis will be reported as means with standard deviations (SDs). To compare the
rates at which SAR302503-Ruxolitinib combination and active control normalize blood counts, a
Chi-squared test will be performed.
7.4 SAMPLE SIZE AND POWER OF STUDY
The following hypotheses will be applied:
The Null Hypothesis: There is no statistically significant difference in Jak2-V617F allele burden
between SAR302503-Ruxolitinib combination treatment group and the active control group at 24
months.
Alternate Hypothesis: There is a statistically significant difference between SAR302503-
Ruxolitinib combination therapy and Ruxolitinib monotherpay in the change in Jak2-V617F allele
burden from baseline to 24 months.
Since there are no previous reports regarding the effect of SAR302503-Ruxolitinib combination
therapy on Jak2-V617F mutant allele burden, we assumed to detect a 15% difference in Jak2-
V617F allele burden between the intervention and active control groups. A previously published
report indicates that SAR302503 reduced Jak2-V617F mutant allele burden by greater than
50% with a standard deviation of 10% (21). In this study, we predict that the standard deviation
will be around 18%. Patients will be randomized to the intervention group and the active control
group in the ratio of 1:1.
We will set the power to .80; that is, there will be an 80% chance of detecting a difference
between the intervention and control groups at the calculated sample size. The level of
statistical significance (two-sided α) will be set at 0.05.
The formula below will be used to determine the sample size:
(1+γ)s2
(zα+ zβ)2
= n
γ (Iµ1- µ2I (1-d)
γ: ratio of randomization
µ1: mean Jak2-V617F allele burden in control group
µ2: mean allele burden in the intervention group
s: standard deviation
d: expected drop-out rate
zα = 1.96 when α = 0.05 (If alternative hypothesis is two-sided)
zβ = 0.84 when β 0.20

15. 15
n = number of subjects in each arm
According to the above calculation, the study will recruit 68 subjects for each arm or a total of
136 subjects.
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