Methotrexate is a first-line disease-modifying drug used to treat rheumatoid arthritis. It works by inhibiting dihydrofolate reductase and other enzymes involved in DNA synthesis, which suppresses the immune system. Newer biological drugs for rheumatoid arthritis target cytokines like tumor necrosis factor-α and interleukin-1β to reduce inflammation. These include TNF-α inhibitors infliximab and etanercept and the IL-1 antagonist anakinra. Recent approvals include janus kinase inhibitors such as upadacitinib, baricitinib, and tofacitinib that block intracellular signaling of proinflammatory cytokines.

1. SYNTHESIS, MECHANISM OF
ACTION AND STRUCTURAL
ACTIVITY OF NEWER DRUGS OF
ARTHRITIS
PRESENTED BY- AQUIB REHANULLAH SIDDIQUI
PH.D. SCHOLAR (PHARMACEUTICAL CHEMISTRY)
INTEGRAL UNIVERSITY

2. Rheumatoid arthritis
Rheumatoid arthritis (RA) is an autoimmune disease in which there is joint
inflammation, synovial proliferation and destruction of articular cartilage. Immune
complexes composed of IGm activate complement and release cytokines (mainly
TNFα and IL-1) which are chemotactic for neutrophils. These inflammatory cells
secrete Lysosomal enzymes which damage cartilage and erode bone, while PGs
produced in the process cause vasodilatation and pain. RA is a chronic
progressive, crippling disorder with a waxing and waning course. Nsaids are the
first line drugs and afford symptomatic relief in pain, swelling, morning stiffness,
immobility, but do not arrest the disease process.

3. TYPES OF ARTHRITIS
• The most common types of arthritis are osteoarthritis and
rheumatoid arthritis.
• Osteoarthritis causes cartilage — the hard, slippery tissue that
covers the ends of bones where they form a joint — to break
down. Rheumatoid arthritis is a disease in which the immune
system attacks the joints, beginning with the lining of joints.
• Uric acid crystals, which form when there's too much uric acid
in your blood, can cause gout. Infections or underlying
disease, such as psoriasis or lupus, can cause other types of
arthritis like Gout, juvenile idiopathic arthritis, osteoarthritis,
psoriatic arthritis, reactive arthritis, rheumatoid arthritis, septic
arthritis, thumb arthritis etc.
• Treatments vary depending on the type of arthritis. The main
goals of arthritis treatments are to reduce symptoms and
improve quality of life

4. SYMPTOMS
• The most common signs and symptoms of arthritis involve the joints. Depending on the type of
arthritis, signs and symptoms may include :
• Pain
• Stiffness
• Swelling
• Redness
• Decreased range of motion

5. RISK FACTORS
• Risk factors for arthritis include:
• Family history. Some types of arthritis run in families, so you may be more likely to develop arthritis
if your parents or siblings have the disorder.
• Age. The risk of many types of arthritis — including osteoarthritis, rheumatoid arthritis and gout —
increases with age.
• Your sex. Women are more likely than men to develop rheumatoid arthritis, while most of the people
who have gout, another type of arthritis, are men.
• Previous joint injury. People who have injured a joint, perhaps while playing a sport, are more likely
to eventually develop arthritis in that joint.
• Obesity. Carrying excess pounds puts stress on joints, particularly your knees, hips and spine. People
with obesity have a higher risk of developing arthritis.

6. DIAGNOSIS
• During the physical exam, doctors check your joints for swelling, redness and warmth. They'll
also want to see how well you can move your joints.
• Laboratory tests - the analysis of different types of body fluids can help pinpoint the type of
arthritis you may have. Fluids commonly analyzed include blood, urine and joint fluid. To obtain
a sample of joint fluid, doctors cleanse and numb the area before inserting a needle in the joint
space to withdraw some fluid.
• Imaging - these types of tests can detect problems within the joint that may be causing your
symptoms. Examples include : X-RAY, CT-scan (computerized tomography), Magnetic
Resonance Imaging (MRI), Ultrasound etc.

7. ANTIRHEUMATOID DRUGS
These are drugs which (except corticosteroids), can suppress the rheumatoid
process, bring about a remission and retard disease progression, but do not have
nonspecific antiinflammatory or analgesic action. They are used in rheumatoid
arthritis (RA) in addition to nsaids and are also referred to as disease modifying
antirheumatic drugs (DMARDs) or slow acting antirheumatic drugs (SAARDs). The
onset of benefit with DMARDs takes a few months of regular treatment and
relapses occur a few months after cessation of therapy. Recently, some biological
agents (antibodies and other proteins) have been added for resistant cases.

8. THE GOALS OF DRUG THERAPY IN RA ARE:
• Ameliorate pain, swelling and joint stiffness
• Prevent articular cartilage damage and bony erosions
• Prevent deformity and preserve joint function.
Though mild/early cases are still mostly treated with NSAIDS only, the current
recommendation is to add DMARDS as soon as the diagnosis of RA is confirmed.
More than one DMARD may be used concurrently; advanced cases may require 2
or 3 drugs together, because all DMARDS tend to lose effectiveness with time.

9. CLASSIFICATION
I. DISEASE MODIFYING ANTIRHEUMATIC DRUGS (DMARDS)
A. NONBIOLOGICAL DRUGS
1. IMMUNOSUPPRESSANTS: METHOTREXATE, AZATHIOPRINE, CYCLOSPORINE
2. SULFASALAZINE
3. CHLOROQUINE OR HYDROXYCHLOROQUINE
4. LEFLUNOMIDE
B. BIOLOGICAL AGENTS
1. TNF-A INHIBITORS: ETANERCEPT, INFLIXIMAB,
ADALIMUMAB
2. IL-1 ANTAGONIST: ANAKINRA
II. ADJUVANT DRUGS
CORTICOSTEROIDS: PREDNISOLONE AND OTHERS

10. METHOTREXATE
• Methotrexate (MTX), formerly known as amethopterin,
is a chemotherapy agent and immune-system suppressant
it is used to treat cancer, autoimmune diseases,
and ectopic pregnancy and for medical abortions.
Types of cancers it is used for include
breast cancer, leukemia,
lung cancer, lymphoma,
and osteosarcoma. (2S)-2-[(4-{[(2,4-DIAMINOPTERIDIN
6YL)METHYL](METHYL)AMINO}BENZOYL)
AMINO]PENTANEDIOIC ACID
• Types of autoimmune diseases it is used for include psoriasis,
rheumatoid arthritis, and cohn's disease it can be given by mouth or by injection.
• Common side effects include nausea, feeling tired, fever, increased risk of infection, low white blood cell
counts, and breakdown of the skin inside the mouth. Other side effects may include liver disease, lung
disease, lymphoma, and severe skin rashes. People on long-term treatment should be regularly checked for
side effects. it is not safe during breastfeeding. In those with kidney problems, lower doses may be
needed. it acts by blocking the body's use of folic acid.
• Although originally designed as a chemotherapy drug (using high doses), in low doses methotrexate is a
generally safe and well-tolerated drug in the treatment of certain autoimmune diseases (including RA).
Because of its effectiveness, low-dose methotrexate is first-line therapy for the treatment of rheumatoid
arthritis. Weekly doses are beneficial for 12 to 52 weeks duration therapy.

12. MOA OF METHOTREXATE
• It is an immunosuppressant meaning it suppresses the immune system, Methotrexate
is a folic analogue and works by inhibiting dihydrofolate reductase (DHFR), DHFR is
an important enzyme in the synthesis of nucleotides.
• Folic acid from our diet is converted to dihydrofolate and through dihydrofolate
reductase becomes tetrahydrofolate, Tetrahydrofolate is converted to 5-10 methyl
tetrahydrofolate which through the enzyme thymidylate synthase becomes
dihydrofolate again.
• This is a double reaction because with this thymidylate synthase also converts
DUMP(Deoxyuridine Monophosphate) to DTMP(Deoxythymidine Monophosphate) and
DTMP through a series of reactions eventually makes Thymine which is part of a
nucleotide that is required for DNA synthesis. Methotrexate is known to inhibit DHFR
but also inhibit thymidylate synthase leading to decreased synthesis of thymine which
is required for DNA synthesis.
• 5-10 methyl tetrahydrofolate becomes 5-methyl tetrahydrofolate through the
enzyme methylene tetrahydrofolate reductase (MTHFR), 5-methyl tetrahydrofolate

13. CONTD…
• The second reaction of Methionine synthase involves conversion of Homocysteine to
Methionine so why is this important well as you can see methotrexate essentially
reduces levels of Methionine and this results in the disruption in the methionine cycle
it reduces Methionine levels and increases Homocysteine level
• Methotrexate also inhibits this enzyme named Amino Imidazole Carboxamide
Ribonucleotide Formyl Transferase also known as AICART this enzyme is important in
the conversion of AICAR to IMP a precursor to Purines, Adenine And Guanine which
are required for RNA and DNA synthesis and so inhibiting AICART it reduces the
purine nucleotides and increases AICAR. Asides from impairing nucleic acid synthesis
to make DNA and RNA it also increases AICAR which is thought to have anti-
inflammatory effects.
• Impaired nucleic acid synthesis suppresses rapidly dividing cells such as immune cells
and so this will essentially disrupt the S phase of the cell cycle responsible for making
DNA thus in rheumatological diseases such as rheumatoid arthritis. It is
immunosuppressive and reduces inflammation and joint destruction because
methotrexate effects nucleic acid synthesis and inhibits the cell cycle from

14. SAR OF METHOTREXATE
• Substitution at ortho and para positions in phenyl ring will decrease the tendency of the
drug to bind with DHFR, thus decreasing the activity of the drug.
• Thiourea entity can increase the activity of the drug
• Combining the drug with copper metal can also increase the activity of the drug.

15. SYNTHESIS OF METHOTREXATE
• Condensation of 2,3-
dibromopropionaldehyde with
2,4,5,6-tetraaminopyrimidine
to produce 6-bromomethyl-
2,4-diaminopteridine.
• 6-bromomethyl-2,4-
diaminopteridine will undergo
further condensation with n-
(para-
(methylamino)benzoyl)glutami
c acid.
• This will lead to the synthesis
of methotrexate.

16. INFLIXIMAB (TNF-a Inhibitor)
• Infliximab, a chimeric monoclonal antibody,
sold under the brand
name REMICADE among others, is a
medication used to treat a number
of autoimmune diseases including arthritis, It
is given by slow injection into a vein typically
at six- to eight-week intervals.
• Infliximab was originally developed in mice
as a mouse antibody. Because humans have
immune reactions to mouse proteins, the
mouse common domains were replaced with
similar human antibody domains. They
are monoclonal antibodies and have identical
structures and affinities to the target.
Because they are a combination of mouse
and human antibody amino acid sequences,
they are called a “chimeric monoclonal

17. MOA OF INFLIXIMAB
• Infliximab is a chimeric immunoglobulin
that targets a Cytokine (small
proteins that are crucial in controlling
the growth and activity of other immune
system cells and blood cells) and binds
and neutralizes tumor necrosis factor
(TNF-alpha) this prevents the TNF-alpha
causing tissue damage.
• TNF-alpha is involved in generating
inflammation as part of an acute phase
reaction and this is an important
cytokine that's involved in a lot of
inflammatory processes in conditions
like Inflammatory Bowel Disease,
Rheumatoid arthritis and psoriasis.
• So, These monoclonal antibodies that
attack this cytokine reduce the
inflammatory response in these
conditions and can be very effective in

18. ANAKINRA (IL-1 ANTAGONIST)
• Anakinra, sold under the brand name kineret, is
a biopharmaceutical medication used to
treat Rheumatoid Arthritis.
• Anakinra is a recombinant form of human
Interleukin-1 Receptor Antagonist used in the
treatment Of Rheumatoid Arthritis and Neonatal-
onset Multisystem Inflammatory Disease.
• Anakinra is a recombinant, nonglycosylated human
interleukin-1 receptor antagonist (IL-1RA). The
difference between anakinra and the native human
IL-1RA is that anakinra has an extra Methionine
residue at the amino terminus. It is manufactured by
using the E. Coli expression system. Anakinra is
composed of 153 amino acid residues. FDA
approved it on november 14, 2001 for the treatment

19. MOA OF ANAKINRA (IL-1 ANTAGONIST)
• Kinneret; Anakinra is a recombinant human interleukin one receptor (IL-1) antagonists
that inhibits the pro-inflammatory molecules Il-1 Alpha And Beta from binding their
receptor.
• Kinneret is indicated for the treatment of rheumatoid arthritis RA in patients 18 years of
age or older who have failed one or more Disease-modifying Antirheumatic Drug
(DMARDs) and treatment of Neonatal Onset Multi-system Inflammatory Disease
(NOMID)
• Inflammation is a complex process mediated by an interdependent network of
cytokines such as the interleukins that regulate the body's response to infection and
injury IL-1 is a key cytokine of the inborn immune system triggers inflammation.
• Within the IL-1 family of cytokines IL-1 alpha and IL-1 beta play a major role in the
inflammation cascade, production of IL-1 alpha further increases the production of IL-1
beta, IL-1 beta then contributes to the migration of Neutrophils and Lymphocytes from
the circulation to areas of inflammation.
• In a healthy person the endogenous IL-1 receptor antagonist IL-1 RA binds the IL-1
receptor displacing IL-1 Kinneret acts with IL-1RA to inhibit IL-1 alpha and beta from
binding their receptor this reduces the IL-1 mediated inflammatory cascade and
associated symptoms in NOMID and RA including headache, fever, rash and swollen

20. SOME NEW DRUGS FOR RHEUMATOID ARTHRITIS
(FDA APPROVED)
• The newest drugs for the treatment of Rheumatoid Arthritis are
the JANUS KINASE (JAK) inhibitors, which are FDA approved
under the brand names Rinvoq, Olumiant, And Xeljanz.
• Janus kinase (JAK) inhibitors work by blocking the activity of
one or more of the Janus Kinase Enzymes (JAK1, JAK2, JAK3,
TYK2) in the JAK-STAT signaling pathway (This pathway
transduces signals from cytokines, interleukins), an
intracellular pathway that plays a major role in the release of
the pro-inflammatory cytokines that stimulate inflammation in
Rheumatoid Arthritis.
• Janus kinase (JAK) inhibitors are part of A wider group of drugs
called DMARDs (disease-modifying anti-rheumatic drugs).
DMARDs work to slow the progression of joint damage in
Rheumatoid Arthritis.

21. CONTD..
DRUGS DRUG
CLASS
ADMINISTRATION COMPANY DATE OF
APPROVAL
RA
INDICATIONS
OTHER
INDICATION
Upadacitinib
(RINVOQ)
Janus
kinase
(JAK)
inhibitor
Oral extended-
release tablets
once daily
Abbvie inc. 16-aug-
2019
 Moderately
to severely
active RA
 Inadequate
response or
intolerance
to
methotrexa
te
 Psoriatic
arthritis
Sarilumab
(KEVZARA)
Interleuki
n-6 (IL-6)
receptor
antagonis
t
Subcutaneous
injection
every 2 weeks
Sanofi and
Regeneron
22-may-
2017
 Moderately
to severely
active RA
 Inadequate
response or
intolerance
 None

22. CONTD..
DRUGS DRUG
CLASS
ADMINISTRATION COMPANY DATE OF
APPROVAL
RA
INDICATIONS
OTHER
INDICATION
Baricitinib
(OLUMIANT)
Janus
kinase
(JAK)
inhibitor
oral tablets once
daily
Eli Lilly and
Company
31-May-
2018
 moderately
to severely
active RA
 inadequate
response to
one or
more TNF
antagonist
therapies
 none
Golimumab
(SIMPONI ARIA)
Tumor
necrosis
factor
(TNF)
blocker
Intravenous
infusion at weeks 0
and 4, then every 8
weeks
Janssen
biotech, inc.
18-jul-
2013
 Moderately
to severely
active RA
 In
combinatio
n with
 Psoriatic
arthritis
 Ankylosing
spondylitis
 Ulcerative
colitis

23. UPADACITINIB [Janus kinase (JAK) inhibitor]
• Upadacitinib, sold under the brand name RINVOQ, is
a Janus Kinase (JAK) Inhibitor medication for the treatment
of moderately to severely active Rheumatoid
Arthritis and Psoriatic Arthritis in adults
where Methotrexate (a drug used to treat active arthritis)
did not work well or could not be tolerated. it was
approved for medical use in the united states and in the
european union in 2019,and was developed by the biotech
company ABBVIE.
• Common side effects include upper respiratory tract
infections (common cold, sinus infections), nausea, cough,
and fever.

24. MOA OF UPADACITINIB [Janus kinase (JAK)
inhibitor]
• The chronic inflammation and joint destruction associated with rheumatoid arthritis have been linked to the
dysregulation of pro-inflammatory cytokines and their associated signaling pathways.
• HOW ARE COMMON PRO-INFLAMMATORY CYTOKINE SIGNALS TRANSMITTED INTO THE CELL NUCLEUS ?
• RA is characterized by an excess of circulating pro-inflammatory cytokines such as TNF alpha or IL-6 which
bind to designated receptors on the cell surface and trigger a complex signaling process inside the cell.
• Different cytokines rely on different signaling pathways to transmit messages to the cell nucleus.
• The JAK-STAT pathway is also thought to play a role in the pathogenesis of RA when properly regulated JAK-
STAT signaling facilitates cell growth development and differentiation especially in immune cells working
together in different combinations the four JAKs (JANUS KINASES) (JAK1, JAK2, JAK3, TYK2) selectively interact
with extracellular cytokines via transmembrane receptors to facilitate signal transduction and initiate a
response within the cell
• These cytokines are involved in immunologic processes including many that when dysregulated are implicated
in RA pathogenesis when a cytokine that signals through the JAK-STAT pathway binds to its receptor on the cell
surface associated JAKs (JANUS KINASES) (JAK1, JAK2, JAK3, TYK2) are recruited and activated which in turn
recruits downstream proteins necessary for message delivery to the nucleus these proteins called SIGNAL
TRANSDUCERS AND ACTIVATORS OF TRANSCRIPTION or STATS become phosphorylated the phosphorylated
STATS translocate to the nucleus where they bind to DNA expression sites and regulate gene transcription this
perpetuates the inflammatory cycle pro-inflammatory cytokine signaling through the JAK-STAT pathway is
thought to contribute to the pathogenesis and progression of RA
• Upadacitinib works by blocking the action of enzymes Called Janus Kinases. These enzymes are involved in
setting up processes that lead to inflammation, and blocking their effect brings inflammation in the joints

25. SYNTHESIS OF UPADACITINIB [Janus kinase (JAK)
inhibitor]

26. SYNTHESIS OF UPADACITINIB [Janus kinase (JAK)
inhibitor]
• The PD-catalyzed coupling reaction between 2-bromo-5-tosyl5h-
pyrrolo[2,3-b]pyrazine (188) and Ethyl Carbamate gave Carbamate
Intermediate 189.
• It was surprisingly discovered that when ethyl carbamate was used,
compound 191 and subsequent compounds could be isolated as crystalline
solids, which eased the purifcation of these intermediates. In contrast, a
previously reported processes of using t-butyl carbamate gave compound
191 which was isolated as amorphous solids. The deprotonation of 189 by
t-buoli (tert-Butyl lithium) in DMA(Dimethyl acetamide), followed by a
substitution reaction with pre-synthesized 190, aforded intermediate 191.
Cyclization of 191 in the presence of Trifuoroacetic Anhydride (TFAA) and
Pyridine produced 192 which was then hydrolyzed with 20% of NAOH at
55 °C to give 193. Hydrogenative cbz deprotection with pd(oh)2/C followed

27. REFERENCES
1. BLOCK J.K, BEALE J. M. WILSON AND GISVOLD’S TEXT BOOK OF ORGANIC MEDICINAL AND
PHARMACEUTICAL CHEMISTRY.11TH EDITION LONDON: LIPPINCOT WILLIAMS AND WILKINS.;
2004; 299-318.
2. WILLIAM D. A, THOMAS.L. FOYE’S PRINCIPALS OF MEDICINAL CHEMISTRY, 6TH EDITION
LIPPINCOTT WILLIAMS AND WILKINS. PHILADELPHIA; 2007; 1046-55.
3. TRIPATHI KD. ESSENTIALS OF MEDICAL PHARMACOLOGY. 5TH EDITION NEW DELHI: JAYPEE
BROTHERS MEDICAL PUBLISHING (P) LTD.; 2004; 770-4.
4. ABRAHAM D. J, BURGERS MEDICINAL CHEMISTRY AND DRUG DISCOVERY,6TH EDITION ; VOL 2;
NEW JERSEY: JOHN WILLEY AND SONS, 2003; 626-637.
5. CORWIN HANSCH. COMPREHENSIVE MEDICINAL CHEMISTRY.VOL 2: PERGAMON PRESS,
NEWYORK; 627-630.
6. WWW.SITEMAKER.UMICH.EDU/MC3/PENI.