Disease-Modifying Therapies
Disease-Modifying Therapies
What You'll Learn
- Treatment goal: NEDA-3 (no relapses, no disability progression, no MRI activity); trend toward early high-efficacy therapy (EHET) over escalation
- Natalizumab: anti-α4-integrin; highest PML risk (JCV+, prior immunosuppression, >24 months); ~68% relapse reduction; severe rebound on discontinuation
- Ocrelizumab: anti-CD20; only PPMS-approved DMT (ORATORIO trial); risk of hypogammaglobulinemia and HBV reactivation
- Fingolimod: S1P modulator; first-dose bradycardia (6-hour cardiac monitoring); macular edema; VZV risk; rebound on stopping
- Alemtuzumab: anti-CD52; secondary autoimmunity (thyroid 30–40%, ITP, anti-GBM nephritis); monthly monitoring for 4 years
- Teriflunomide: contraindicated in pregnancy and in females of reproductive potential not using effective contraception (FDA pregnancy letter categories were retired in 2015 with the PLLR); accelerated elimination with cholestyramine or activated charcoal if pregnancy occurs or rapid drug clearance is needed
- Glatiramer acetate and interferon-β: most reassuring pregnancy experience; either may be continued through conception/pregnancy in selected patients after risk-benefit discussion; no washout required
- Dimethyl fumarate: Nrf2 pathway; PML risk if sustained lymphopenia (ALC <500 for >6 months)
HighYield Pearls
- Natalizumab + JCV antibody positive + >2 yr therapy + prior immunosuppression: highest PML risk — stratify by JCV index, switch to anti-CD20 if index rises
- Fingolimod first dose: 6-hour cardiac monitoring for bradycardia/AV block; baseline OCT for macular edema; VZV serology + vaccinate seronegative patients before starting
- Ocrelizumab: only DMT FDA-approved for PPMS (ORATORIO); screen HBV + vaccinate before infusion; watch hypogammaglobulinemia long-term
- Alemtuzumab: secondary autoimmunity (Graves 30–40%, ITP, anti-GBM glomerulonephritis) emerges months-years later → monthly CBC/Cr/UA + thyroid q3mo for 4 yr after last dose
- Teriflunomide: contraindicated in pregnancy and in females of reproductive potential not using effective contraception (FDA pregnancy letter categories retired in 2015); accelerated elimination protocol = cholestyramine 8 g TID × 11 days (or activated charcoal) if pregnancy occurs or rapid clearance is needed (men & women)
- Glatiramer acetate: among the most reassuring pregnancy DMTs (along with interferon-β) — may be continued through gestation in selected patients; immediate post-injection reaction (flushing/chest tightness/dyspnea) is self-limited, not anaphylaxis
- Natalizumab/fingolimod discontinuation: severe REBOUND disease activity — bridge to anti-CD20 with short washout to avoid lymphopenia overlap
- Dimethyl fumarate + sustained ALC <500 for >6 mo: PML risk — check CBC q3mo and hold if persistent lymphopenia
- Cladribine: 2-year oral course with durable lymphocyte depletion; pregnancy contraindicated × 6 mo after last dose (both sexes)
- Suspected PML on natalizumab: STOP drug + PLEX for accelerated removal + serial MRI/JCV PCR; IRIS may follow
🔍 Quick ReferenceMechanism / drug class · Adverse effects / monitoring · Pregnancy / switching
Mechanism / drug class
- Anti-α4-integrin (VLA-4) blocks lymphocyte CNS entry → natalizumab
- S1P1 receptor internalization → lymphocyte sequestration in lymph nodes → fingolimod, siponimod, ozanimod, ponesimod
- Anti-CD20 B-cell depletion → ocrelizumab (IV), ofatumumab (SC), ublituximab (IV)
- Anti-CD52 depletes T & B cells × 2-yr induction course → alemtuzumab
- Nrf2 pathway activator (antioxidant response) → dimethyl/diroximel/monomethyl fumarate
- Dihydroorotate dehydrogenase (DHODH) inhibitor → pyrimidine synthesis → teriflunomide
- Random poly-amino-acid peptide mimics MBP → glatiramer acetate (Copaxone)
- Purine analog → selective lymphocyte depletion (oral 2-yr course) → cladribine
- Only DMT approved for PPMS (ORATORIO trial) → ocrelizumab
Adverse effects / monitoring
- First-dose bradycardia + 6-hr cardiac monitoring + macular edema (baseline OCT) → fingolimod
- PML with JCV+ antibody, prior immunosuppression, >24 mo therapy → natalizumab (also rare with fumarates, fingolimod)
- Secondary autoimmunity: Graves/thyroid 30–40%, ITP, anti-GBM glomerulonephritis → alemtuzumab
- Flu-like symptoms + injection site reactions + LFT elevation + neutralizing antibodies → IFN-β
- Immediate post-injection reaction (flushing, chest tightness, dyspnea, anxiety) + lipoatrophy → glatiramer acetate
- Flushing + GI upset + sustained lymphopenia → PML risk → dimethyl fumarate (Vumerity/Bafiertam reduce GI)
- Hair thinning + diarrhea + hepatotoxicity + pregnancy contraindication (accelerated elimination required) → teriflunomide
- Infusion reactions + HBV reactivation + hypogammaglobulinemia long-term → anti-CD20 (ocrelizumab, ofatumumab, ublituximab)
- Cryptococcal meningitis + VZV reactivation → S1P modulators (fingolimod)
- Cardiotoxicity (cumulative dose) + therapy-related AML → mitoxantrone (historical)
Pregnancy / switching / pearls
- Most reassuring pregnancy experience among MS DMTs — may be continued in selected patients → glatiramer acetate and interferon-β
- Pregnancy contraindicated — cholestyramine 8 g TID × 11 days for accelerated elimination if pregnancy occurs / before conception → teriflunomide
- Severe rebound disease activity on discontinuation → natalizumab, fingolimod (bridge to anti-CD20)
- Switching from S1P modulator to anti-CD20 → short washout to avoid lymphopenia overlap
- Aggressive highly active RRMS refractory to high-efficacy DMTs → autologous HSCT (RIC + cyclophosphamide + rATG)
- Early high-efficacy therapy (EHET) > escalation → better long-term outcomes (CLAIMS, NOVA registries)
- JCV antibody index annually (every 6 mo if positive) → natalizumab PML stratification
- Live vaccines avoided + complete vaccination before B-cell depletion or S1P modulator → ocrelizumab, fingolimod
- NEDA-3 (no relapse + no MRI activity + no disability progression) → current treatment goal — failure prompts escalation
Treatment Strategy
Escalation vs Early High-Efficacy Therapy (EHET)
| Approach | Strategy | When to Consider |
|---|---|---|
| Escalation | Start moderate-efficacy DMT (interferon, glatiramer, teriflunomide, dimethyl fumarate); escalate if breakthrough disease | Low relapse rate, low lesion burden, favorable prognostic features, older age, mild CIS |
| Early high-efficacy therapy (EHET) | Start with high-efficacy DMT (natalizumab, ocrelizumab, alemtuzumab, cladribine) from diagnosis | High relapse rate, high lesion burden, brainstem/spinal cord lesions, young age, poor prognostic features |
- Trend shifting toward EHET — observational data suggest better long-term outcomes when high-efficacy therapy started early
- No RCTs directly comparing escalation vs EHET — evidence from observational registries (MSBase, SUMMIT)
NEDA-3 (No Evidence of Disease Activity)
| Component | Definition |
|---|---|
| No relapses | No clinical attacks over assessment period |
| No disability progression | No confirmed EDSS worsening sustained for 3–6 months |
| No MRI activity | No new/enlarging T2 lesions and no Gd-enhancing lesions |
- NEDA-4 adds brain volume loss (<0.4%/year) as fourth measure (not yet standard in practice)
💎 Board Pearl
- NEDA-3 is the current treatment target — no relapses + no disability progression + no MRI activity
- Failure to achieve NEDA-3 should prompt consideration of switching to a higher-efficacy DMT
Injectable DMTs (Moderate Efficacy)
Interferons & Glatiramer Acetate
| Drug | Mechanism | Efficacy | Key Side Effects | Monitoring |
|---|---|---|---|---|
| IFN-β1a (Avonex — IM weekly; Rebif — SC 3×/wk) | Immunomodulatory: ↓ T-cell activation, ↓ BBB permeability, Th1 → Th2 shift, antiviral | ~30% relapse reduction | Flu-like symptoms, injection site reactions, hepatotoxicity, depression, leukopenia | CBC, LFTs q3–6 months; neutralizing antibodies if breakthrough |
| IFN-β1b (Betaseron, Extavia — SC QOD) | Same as IFN-β1a | ~30% | Same; slightly more injection site reactions | Same |
| Peginterferon-β1a (Plegridy — SC q2 weeks) | Pegylated IFN-β1a; longer half-life | ~36% | Same as interferons; less frequent dosing | Same |
| Glatiramer acetate (Copaxone — SC daily or 40 mg 3×/wk) | Synthetic MBP analog; induces Th2 shift; generates regulatory T cells | ~29% | Injection site reactions, lipoatrophy, immediate post-injection reaction (chest tightness, flushing — benign, self-limited; occurs in ~10%) | None required routinely; safest DMT in pregnancy |
💎 Board Pearl
- Glatiramer acetate is the safest DMT in pregnancy — no washout required; often used as bridge therapy
- Interferons: check neutralizing antibodies if breakthrough disease on therapy — up to 25–45% develop NAbs
- Interferons and glatiramer are moderate-efficacy (~30% relapse reduction) — adequate for mild disease, not for aggressive MS
Continue reading — sign in
The full note has more clinical pearls, tables, and board-focused tips. Free account, no fee.