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Rheumatology Biologics

“The Memory Palace”

The Analogy

This guide uses a memory palace — a technique where you walk through a familiar space and place what you need to remember in specific locations. Each room in the house maps to a drug class. Each fixture maps to a specific drug or mechanism.

Start outside. There’s a garden hose spraying water onto the lawn. The water is cytokines. The grass is the receptor on the cell. Walk through the front door, into the living room, the kitchen, B-cell death row, the garage, and out to the backyard. By the time you’re done, every biologic has a home.

Pro tip — make it your house. Walk through your own place (or a friend’s house, your childhood home) either physically or mentally. The weirder the image, the stickier the memory.

Step 1 · 5 min
Drug Suffixes
The Garden Hose
Step 2 · 5 min
WHO Naming
The Labeling System
Step 3 · 5 min
Name Cheat Codes
Hidden Gems
Step 4 · 15 min
Drug-by-Drug
The House Tour
Step 1

The Garden Hose — “What Kind of Fix Is It?”

The grass is the receptor on the cell. Three ways to stop the water from hitting the grass:

Garden hose analogy — MABs soak up stream, CEPTs catch runoff, INIBs clog hose
SuffixTypeHow It Works
-mabMonoclonal antibodyGoes straight for the source — soaks up the stream before it hits the grass.
-ceptReceptor fusion proteinHolds a bucket between the nozzle and the grass — a decoy that catches the water.
-inibSmall molecule inhibitorClogs the hose from the inside — the flow stops, but you can’t see why from outside.
MABs go straight for the source, CEPTs catch the runoff, INIBs clog the course.

MABs and CEPTs work outside the cell — they intercept cytokines in the bloodstream or synovial space. INIBs are small enough to get inside the cell and block signaling pathways (like JAK-STAT). The hose looks fine from the outside, but something’s clogged inside.

Step 2

The Labeling System — “Read the Name, Know the Fix”

Every biologic has a name stamped on it by the WHO. The ending before -mab tells you how human the antibody is. More mouse protein = more immunogenicity = more likely you’ll need methotrexate backup.

SubstemOriginMnemonic
-o-mabFully mouse“O no, it’s all mOuse!”
-xi-mabChimeric (mixed)“miXI-mab = a MIX of mouse and man”
-zu-mabHumanized“ZU-mab = almost human, just a ZU-spicion of mouse”
-u-mabFully human“U-mab = it’s all hUman, it’s all U”
O is mOuse, X is miXed, ZU is humanized betwixt, U is hUman — least immunogenic in the mix.
Why this matters clinically: Chimeric (-ximab) antibodies are most immunogenic → anti-drug antibodies form → loss of efficacy over time. This is why infliximab needs methotrexate as a co-pilot. Fully human (-umab) antibodies are least immunogenic → can often be used as monotherapy.
Step 3

Name Cheat Codes — “Free Points in the Syllables”

Hidden Gems: Drug Names That Teach Themselves

DrugWhat’s HidingMnemonic
HUMIRAHUman Monoclonal antibody In Rheumatoid ArthritisThe brand name IS the mechanism + indication
AnakinraAna-KIN-RA = ANtagonist of interleuKIN Receptor Alpha/betaThe drug IS the body’s own IL-1Ra, cloned
Anifrolumab“-fro-” = interFROn (WHO infix)AN-ti-interFRO-n-lu-mab — the target is in the middle
BenlystaB-lymphocyte stimulator antibody“BenLYSTA — the B-LySt Antibody.”
Step 4

The House Tour — “Room by Room, Drug by Drug”

Now you have the tools and the cheat codes. Time to walk through the house. Each room maps to a drug class. For each drug, notice how the name confirms what you already know from Steps 1–3.

🚨

The Front Door — IL-1 Inhibitors

IL-1 is the front door — the first signal that kicks off autoinflammatory fires (gout, FMF, CAPS, Still’s disease). These drugs guard the door.

ANAKINRAReceptor Antagonistαβ✕✕ANA blocks ALL at the doorWall = IL-1 Receptor (door)α + β: both blocked ✓CANAKINUMABAnti-IL-1β mAb — β onlyαβ✕CANAαcrawls in!α in →Wall = IL-1 Receptor (door)β blocked · α crawls in ✗RILONACEPT-cept = Decoy Receptor TrapαβαβDECOY DOOR(-cept = trap)Real receptor — unreachedα + β: both trapped ✓
α = IL-1 alphaβ = IL-1 betaWall = IL-1 Receptor
“ANA catches ALL at the wall. CANA lets alpha crawl in. RILO snaps the trap — -cept gets ‘em all.”

Anakinra SC

Kineret
Mechanism
IL-1 receptor antagonist (recombinant IL-1Ra). Blocks both alpha and beta.
Dosing
100 mg SC daily
FDA
RA (FDA-approved, but rarely used clinically due to daily SC injections), CAPS (NOMID). Also used for gout flares, Still’s disease, FMF, recurrent pericarditis.
Injection site reactions common. Short half-life = quick washout if infection develops.

Canakinumab SC

Ilaris
Mechanism
Monoclonal antibody against IL-1β specifically.
Dosing
150 mg SC every 8 weeks (varies by indication)
FDA
CAPS, SJIA, TRAPS, HIDS/MKD, FMF, gout flare prevention.
CANTOS trial: reduced cardiovascular events — board-testable.

Rilonacept SC

Arcalyst
Mechanism
Soluble decoy receptor (“IL-1 Trap”) — the -cept tells you it’s a decoy. Catches both IL-1α and IL-1β.
Dosing
320 mg SC loading, then 160 mg SC weekly
FDA
CAPS and recurrent pericarditis.
IL-1 Dosing rhythm: “ANA every DAY, RILO every WEEK, CANA every EIGHT — the IL-1 triple feat.”
🌡️

The Thermostat — IL-6 Inhibitors

IL-6 controls the thermostat — it drives fever and CRP. Block IL-6 and the thermostat reads normal. But the house is still burning. That’s the board trap: the smoke alarm (CRP) goes silent, but the fire (infection) is still raging.

“TOCI TOUCHES the SIX receptor — Giant Cell’s protector. SARI wraps SIX — same receptor, different fix.”

Tocilizumab IVSC

Actemra
Mechanism
Humanized monoclonal antibody against the IL-6 receptor (IL-6R). Blocks IL-6 signaling at the receptor level. IV or SC.
Dosing
IV 4–8 mg/kg every 4 weeks; SC 162 mg weekly or every 2 weeks
FDA
RA, GCA, SJIA, PJIA, CRS (CAR-T), SSc-ILD.
First-line for GCA (GiACTA trial). Monitor lipids. Risk of GI perforation. Masks infection signs — CRP stays low.

Sarilumab SC

Kevzara
Mechanism
Fully human monoclonal antibody against the IL-6 receptor (IL-6R). Binds IL-6R with higher affinity than tocilizumab. SC only.
Dosing
200 mg SC every 2 weeks
FDA
RA, PMR, polyarticular JIA.
Fully human (-umab) vs. tocilizumab’s humanized (-zumab) = potentially lower immunogenicity. Higher receptor-binding affinity than tocilizumab. SC only — no IV option.
📺

The TV — IL-17 & IL-12/23 Inhibitors

IL-17 drives inflammation in the skin and spine. Think of it as an R-rated channel — you must be SEVENTEEN to watch.

IL-17 Inhibitors — TV with security guard checking IDs at Channel 17
“SECU-rity checks IDs at SEVENTEEN — but Crohn’s gets cancelled from the screen.”

Secukinumab and ixekizumab target IL-17A only. Bimekizumab targets both IL-17A and IL-17F.

“The BI in BImekizumab = two targets. IL-17A and IL-17F. Every other IL-17 inhibitor only blocks one.”

Secukinumab SC

Cosentyx
Target
IL-17A
Dosing
150–300 mg SC; loading dose varies, then every 4 weeks
FDA
Plaque psoriasis, PsA, AS, nr-axSpA, HS.
Watch for Candida infections. Avoid in IBD (can worsen Crohn’s).

Ixekizumab SC

Taltz
Target
IL-17A
Dosing
160 mg SC loading, then 80 mg SC every 2–4 weeks
FDA
Plaque psoriasis, PsA, AS, nr-axSpA.
Same IL-17A target as secukinumab. Watch for Candida and IBD exacerbation.

Bimekizumab SC

Bimzelx
Target
IL-17A and IL-17F
Dosing
320 mg SC every 4 weeks initially, then every 4–8 weeks
FDA
Plaque psoriasis, PsA, AS, nr-axSpA.
“BImekizumab = BI-target. The only drug in the room that blocks both A and F simultaneously.”
Dual IL-17A/F inhibition leads to superior skin clearance vs. IL-17A-only agents. Higher rates of oral candidiasis. Avoid in IBD (class effect).

IL-12/23 and IL-23 Inhibitors

“USTE blocks the USUAL TWO — twelve AND twenty-three are through. GUSEL and RISAN are precise — only twenty-three, that’s their device.”

Ustekinumab SCIV loading

Stelara
Target
p40 subunit shared by IL-12 and IL-23
Dosing
Weight-based IV loading, then 90 mg SC every 8 or 12 weeks
FDA
Plaque psoriasis, PsA, Crohn’s, UC.
Works for IBD — unlike IL-17 inhibitors. Excellent safety profile.

Guselkumab SC

Tremfya
Target
p19 (IL-23 selective)
Dosing
100 mg SC weeks 0 and 4, then every 8 weeks
FDA
Plaque psoriasis, PsA, AS, nr-axSpA.

Risankizumab SC

Skyrizi
Target
p19 (IL-23 selective)
Dosing
150 mg SC weeks 0 and 4, then every 12 weeks; IV loading for Crohn’s
FDA
Plaque psoriasis, PsA, Crohn’s disease, UC.
❄️

The Kitchen Freezer — TNF Inhibitors

TNF is the biggest flood in the house — the most cytokine, the most damage. Five drugs stop it. But notice where they live: the kitchen freezer. That’s not random.

🧊 Why the Fridge? — Biology Meets Memory

These are biologics — large protein molecules that are temperature-sensitive and must be refrigerated. You can’t put them in a cabinet like a pill. They live in the fridge because they are proteins.

And they work extracellularly — out in the open, in the synovial space and bloodstream, intercepting TNF-alpha before it can dock on its receptor. Compare that to the garage: JAK inhibitors are small molecules that sneak inside the cell and cut the wiring. These never get that far. They freeze the flood before it even reaches the door.

Biologics in the fridge. Small molecules in the cabinet. That’s the divide.

“Five on ICE — biologics, temperature-sensitive proteins that intercept TNF’s call before it reaches the cell.”

Open the fridge: 🍞 Adalimumab is the bread (Humira is the loaf, every slice is a biosimilar). 🍪 Infliximab is the cookie (give a mouse a cookie without MTX, they’ll keep coming back). 🧈 Etanercept is the margarine (I Can’t Believe It’s Not a MAB). 🥛 Certolizumab is the milk (safe to share with baby). Golimumab is in the back (once a month — easy to forget it’s there).

Adalimumab SC

Humira
Mechanism
Fully human monoclonal antibody against TNF-alpha.
Name cheat
HUMIRA = HUman Monoclonal antibody In Rheumatoid Arthritis
Dosing
40 mg SC every 2 weeks
FDA
RA, JIA, PsA, AS, plaque psoriasis, Crohn’s, UC, uveitis, HS.
“Adalimumab is the LOAF OF BREAD — Humira is the original loaf, and every slice is a biosimilar. Same bread, different wrapper.”
Most prescribed biologic in the world. More biosimilars than any other drug (35+). Fully human (-u-mab) = 100% pure. Every slice is interchangeable.

Infliximab IV

Remicade
Mechanism
Chimeric monoclonal antibody. IV only.
Dosing
3–10 mg/kg IV; induction at weeks 0, 2, 6, then every 4–8 weeks
FDA
RA, Crohn’s, UC, AS, PsA, plaque psoriasis.
“Infliximab is the COOKIE — If You Give a Mouse a Cookie. It’s chimeric (part mouse, part human), and mice love cookies. Give infliximab without MTX and the mouse will form anti-drug antibodies and keep coming back for more.”
Chimeric (-ximab) = highest immunogenicity among TNF inhibitors → must pair with methotrexate. IV only — no SC option. Check for latent TB before ALL TNF inhibitors. Can trigger drug-induced lupus.

Etanercept SC

Enbrel
Mechanism
Soluble TNF receptor fusion protein (decoy receptor). The ONLY -cept among TNF blockers.
Dosing
50 mg SC weekly
FDA
RA, JIA, PsA, AS, plaque psoriasis.
“Etanercept is MARGARINE — ‘I Can’t Believe It’s Not a MAB.’ It looks and works like the others for joints, but it’s a fusion protein (-cept), not a monoclonal antibody. And like margarine, don’t substitute it for IBD — it just won’t work.”
The ONLY fusion protein (decoy receptor) among TNF inhibitors — not a MAB. Does NOT work for IBD, granulomatous disease, or uveitis.

Certolizumab Pegol SC ✓ Pregnancy

Cimzia
Mechanism
PEGylated Fab fragment — NO Fc portion. Cannot cross the placenta.
Dosing
400 mg SC weeks 0, 2, 4; then 200 mg every 2 weeks (or 400 mg every 4 weeks)
FDA
RA, Crohn’s, PsA, AS, nr-axSpA, plaque psoriasis.
“Certolizumab is the MILK — safe to share with baby. No Fc region = no placental transfer = the only TNF inhibitor you can prescribe to a pregnant or breastfeeding patient.”
No Fc region = no active placental transport via FcRn = minimal fetal exposure. Also transfers minimally into breast milk. The only TNF inhibitor safe in pregnancy and breastfeeding. #1 board-tested fact.

Golimumab SCIV option

Simponi / Simponi Aria
Mechanism
Fully human monoclonal antibody. Monthly SC dosing.
Dosing
Simponi 50 mg SC monthly; Simponi Aria 2 mg/kg IV every 8 weeks
FDA
RA, PsA, AS, UC.
“GOLImumab — GO once a month, Live your life.”
💀

B-Cell Death Row

B-cell death row, five ways to go. These drugs target B cells through depletion or starvation — each a different way to eliminate rogue B cells driving autoimmunity.

“B-cell death row, five ways to go:
RITUXIMAB — CD20’s last RITE.
OBI — the OBITUARY, same target, deadlier bite.
INE-B — INEVITABLE, NINETEEN swept clean.
BELI — BELLY-empty, no BLyS to feed the machine.
CAR-T — your own cells, reprogrammed and mean.”

Rituximab IV

Rituxan
Target
CD20 on B cells
Type
Type I anti-CD20 (chimeric IgG1). Kills via CDC and ADCC.
Key uses
RA (after TNF failure), ANCA vasculitis (GPA/MPA), pemphigus vulgaris, SLE (second-line), IgG4-RD (off-label).
RITUXIMAB = CD20’s last RITE. A ritualistic elimination of B cells bearing CD20.
Check hepatitis B before starting — risk of reactivation. Monitor immunoglobulins with repeated cycles.

Obinutuzumab IV

Gazyva
Target
CD20 (glycoengineered, more potent than rituximab)
Type
Type II anti-CD20 (humanized). Enhanced direct cell death + ADCC; less CDC than rituximab.
Key uses
Lupus nephritis (FDA-approved Oct 2025). Originally approved in CLL/lymphoma.
OBI writes the OBITUARY — same target, deadlier bite.
REGENCY Phase III: 46.4% complete renal response on MMF + glucocorticoids. Only anti-CD20 mAb to show complete renal response benefit in a Phase III lupus nephritis trial. Administered twice yearly after 4 initial doses in year one.

Inebilizumab IV

Uplizna
Target
CD19 (broader than CD20 — catches plasmablasts and some plasma cells)
Key uses
NMOSD (N-MOmentum trial). IgG4-related disease (FDA-approved Apr 2025, MITIGATE trial — first approved treatment for IgG4-RD).
INE-B = INEVITABLE, NINETEEN swept clean.
CD19 is expressed earlier and later in B-cell development than CD20 — inebilizumab catches cells that rituximab misses, including antibody-secreting plasmablasts. MITIGATE trial: 87% reduction in IgG4-RD flare risk.

Belimumab SCIV

Benlysta
Target
BLyS / BAFF (B-lymphocyte stimulator) — starves B cells rather than killing them directly.
Key uses
SLE (first drug approved for lupus in 50+ years), lupus nephritis (BLISS-LN trial).
BELI = BELLY-empty — no BLyS to feed the machine.
Doesn’t deplete B cells directly — blocks the survival signal. Takes months for full effect. Often combined with standard therapy.

CAR-T Cell Therapy

Chimeric Antigen Receptor T cells — Experimental in Autoimmune Disease
Target
CD19 (via patient’s own reprogrammed T cells)
Mechanism
T cells harvested, engineered with a CD19-targeting receptor, and reinfused. A one-time living therapy — the reprogrammed T cells persist and hunt B cells.
Key uses
Mackensen et al. (NEJM 2022): deep remission in SLE, myositis, and systemic sclerosis. Active trials in lupus nephritis, ANCA vasculitis, and more.
CAR-T = your own cells, reprogrammed and mean.
Cytokine release syndrome (CRS) is the major risk. Unlike conventional drugs, this is potentially curative — drug-free remissions reported lasting 1–2+ years.
🔑

Other Key Players

Abatacept SCIV

Orencia — T-Cell Co-Stimulation Blocker
Mechanism
CTLA-4-Ig fusion protein. Blocks Signal 2 (the co-stimulatory handshake between APC and T cell).
Dosing
Weight-based IV monthly; or 125 mg SC weekly
FDA
RA, JIA, PsA.
“ABATE the handshake — T cells won’t awake.”
It’s a -CEPT (receptor fusion protein). DO NOT combine with TNF inhibitors.

Anifrolumab IV

Saphnelo — Type I Interferon Blocker
Mechanism
Monoclonal antibody against type I interferon receptor (IFNAR1).
Name cheat
AN-ti-interFRO-n-lu-mab — the target is in the name.
Dosing
300 mg IV every 4 weeks
FDA
Moderate-to-severe SLE (TULIP-1, TULIP-2 trials).
Increased risk of herpes zoster — type I IFN is critical for antiviral defense.

Avacopan Oral

Tavneos — Complement Inhibitor
Mechanism
Oral C5a receptor antagonist. Blocks C5a from binding its receptor, cutting off complement-driven neutrophil activation.
Dosing
30 mg PO twice daily
FDA
Adjunctive treatment for ANCA vasculitis (GPA and MPA).
“AVA-copan ADVOCATES by phone — blocks C5a’s call so steroids can go home.”
ORAL medication (the only oral complement inhibitor in rheumatology). ADVOCATE trial: non-inferior to prednisone taper at 52 weeks. Steroid-sparing.
⚠ FDA Safety Warning — Drug-Induced Liver Injury (DILI)

Post-marketing reports of serious hepatotoxicity including fatal cases and vanishing bile duct syndrome. Monitor LFTs at baseline and periodically during treatment. Discontinue if significant liver injury develops.

⚡

The Garage — JAK Inhibitors (The Electrical Panel)

JAK inhibitors sneak into the electrical panel and cut the wiring — the intracellular signaling system that tells everything to turn on. Unlike the biologics in the fridge (which work outside the cell), JAKi are small molecules that penetrate the cell and interrupt signaling at the source.

JAK Inhibitors Electrical Panel — breaker switches showing selectivity
“TOFA’s a TOTAL blackout, BARI BARS the first two, UPA blocks just one — JAK1, that’s you.”

Tofacitinib Oral

Xeljanz
Selectivity
JAK1 + JAK3 (> JAK2). TOFA = TOTAL blackout.
Dosing
5 mg PO twice daily (or 11 mg XR once daily)
FDA
RA, PsA, UC, JIA, AS.
First FDA-approved JAK inhibitor (2012). Boxed warning: increased risk of MACE, VTE, malignancy (ORAL Surveillance trial). Applies as a class warning to all JAKi.

Baricitinib Oral

Olumiant
Selectivity
JAK1 + JAK2. BARI BARS the first two.
Dosing
2 mg PO once daily
FDA
RA, alopecia areata.
“BARI builds a BARRIER — walls off JAK 1 and 2, nothing getting through.”

Upadacitinib Oral

Rinvoq
Selectivity
JAK1 selective. UPA = just U — JAK1 only.
Dosing
15 mg PO once daily (RA, PsA, AS); 30–45 mg for IBD induction
FDA
RA, PsA, AS, nr-axSpA, GCA, atopic dermatitis, UC, Crohn’s.
Most JAK1-selective. Broadest indication list of the JAKi class.
🎛️

The Smart Thermostat — TYK2 Inhibitor

Same garage. Different panel entirely. TYK2 is a member of the JAK family — but deucravacitinib doesn’t touch it the same way.

⚡ Other JAK Inhibitors (TOFA / BARI / UPA)

Bind the active kinase domain (JH1) — the main breaker. Block ATP from binding, cutting power to the whole circuit.

🎛️ Deucravacitinib (DEUCE)

Binds the regulatory pseudokinase domain (JH2) — the dimmer switch. Locks TYK2 in an inactive conformation without touching the active site. A fundamentally different mechanism.

🔍 Why This Matters

TYK2’s JH2 regulatory domain is structurally distinct from JAK1, JAK2, and JAK3. DEUCE fits only that lock — which is why it’s highly TYK2-selective without off-target JAK effects. That selectivity is what allows it to skip the JAK inhibitor class boxed warning (no MACE/VTE/malignancy warning). It also means it can be used where JAKi class concerns would otherwise give pause.

TYK2 mediates downstream signaling of IL-23, IL-12, and type I IFN — exactly the cytokines that drive psoriasis and PsA pathology.

Deucravacitinib Oral

Sotyktu
Mechanism
Selective TYK2 inhibitor via allosteric binding to the regulatory pseudokinase domain (JH2) — not the active site (JH1).
Dosing
6 mg PO once daily
FDA
Plaque psoriasis, PsA (first TYK2 inhibitor for PsA — POETYK PsA-1 and PsA-2 trials).
“DEUCE hits TYK-TWO on the back panel — not the breaker, but the dimmer, that’s the channel.”
No JAK inhibitor class boxed warning — the different binding mechanism means the ORAL Surveillance-style risks don’t apply. This is a key clinical and counseling point.
⛺

The Backyard — PDE4 Inhibitor

Picture kids camping in the backyard — tents up, everything calm. cAMP = the CAMP. PDE4 normally breaks down cAMP (tears down the tents). Apremilast blocks PDE4 — the kids keep camping, everything stays calm.

“Block PDE, let cAMP stay — APREMILAST saves the day.”

Apremilast Oral

Otezla
Mechanism
PDE4 inhibitor. Oral. Raises intracellular cAMP → reduces inflammatory cytokine production.
Dosing
Titrate over 6 days to 30 mg PO twice daily
FDA
PsA, plaque psoriasis, oral ulcers in Behçet’s disease.
Oral, no lab monitoring required. Side effects: diarrhea, nausea, weight loss, headache, depression. Less efficacious than biologics but easiest to start. Behçet’s oral ulcers = unique niche indication.

The Whole House at a Glance

🌿 Garden Hose

MABs go straight for the source, CEPTs catch the runoff, INIBs clog the course.

🚨 Front Door (IL-1)

ANA blocks ALL IL-ONE at the door. CANA? CAN only block beta, nothing more.

🌡️ Thermostat (IL-6)

TOCI TOUCHES the SIX receptor — Giant Cell’s protector. CRP goes silent, but infection still burns.

📺 TV (IL-17)

SECU-rity checks IDs at SEVENTEEN — Crohn’s gets cancelled from the screen.

📺 TV (IL-12/23)

USTE blocks the USUAL TWO. GUSEL and RISAN are precise — only twenty-three, that’s their device.

❄️ Kitchen Freezer (TNF)

Five biologics on ICE — proteins that intercept TNF extracellularly, before it reaches the cell. CERTified PEG-nant friendly. The CEPT can CATCH but can’t CROHN’S.

💀 B-Cell Death Row

Rituximab — last RITE (CD20). Obinutuzumab — OBITUARY. Inebilizumab — INEVITABLE (CD19). Belimumab — BELLY-empty. CAR-T — reprogrammed and mean.

🔑 Other Key Players

AN-ti-interFRO-n (anifrolumab). AVA ADVOCATES by phone — steroids can go home.

⚡ Garage (JAK)

TOFA’s a TOTAL blackout, BARI BARS the first two, UPA blocks just one — JAK1, that’s you.

🎛️ Garage (TYK2)

DEUCE hits TYK-TWO on the back panel — not the breaker, but the dimmer, that’s the channel. No class boxed warning.

⛺ Backyard (PDE4)

Block PDE, let cAMP stay — APREMILAST saves the day.