Zasocitinib (Next-Gen TYK2) LATITUDE Phase 3: Week 16 sPGA 0/1 ~70% — A Once-Daily Oral Could Reset Plaque Psoriasis Treatment
Takeda’s next-generation selective oral TYK2 inhibitor zasocitinib (TAK-279) achieved approximately 70% sPGA 0/1 (clear or almost clear) at week 16 in the Phase 3 LATITUDE-1 and LATITUDE-2 trials in moderate-to-severe plaque psoriasis. PASI 90 over 50%, PASI 100 around 30%, rapid response onset by week 4, and 90%+ response maintenance through week 60. After AAD 2026 late-breaking presentation, Takeda confirmed FDA NDA filing for fiscal 2026. A once-daily oral pill with biologic-level efficacy.
The Data
LATITUDE-1 (n=693) and LATITUDE-2 (n=1,108) evaluated zasocitinib in moderate-to-severe plaque psoriasis adults. Co-primary endpoints: week 16 sPGA 0/1 and PASI 75. Secondaries: PASI 90/100, time to response, week 60 maintenance.
Key results:
- sPGA 0/1: ~70% (placebo 5-10%)
- PASI 90: 50%+ at week 16 (placebo 4-8%)
- PASI 100 (complete clearance): ~30% at week 16
- Rapid onset: significant PASI 75 vs placebo by week 4
- 24-week cumulative: response continues to deepen
- 60-week maintenance: 90%+ of week 40 responders maintained
- Safety: consistent with Phase 2b. No new signals. Common AEs: upper respiratory infection, acneiform eruption
Phase 2b efficacy reproduced more strongly in Phase 3. Takeda formalized FDA NDA filing plans for fiscal 2026 (April 2026 - March 2027).
Why TYK2 Differs from Other JAK Inhibitors
Among the JAK family, TYK2 mediates IL-12 and IL-23 signaling. The IL-23 → TYK2 → STAT3 → IL-17 axis is the molecular core of plaque psoriasis.
Existing JAK inhibitors (tofacitinib, baricitinib, upadacitinib) deliver broad JAK1/JAK2/JAK3 blockade — powerful but with broad side effects (anemia, neutropenia, MACE signal, infection risk).
Zasocitinib is TYK2-selective. Minimal effect on JAK1/2/3 means only IL-12/IL-23 signaling is blocked while other immune functions remain intact. Compared to deucravacitinib (FDA-approved 2022, the first TYK2 inhibitor), the next-generation zasocitinib offers stronger TYK2 selectivity and higher efficacy.
Limits of Current Plaque Psoriasis Treatment
- Topical corticosteroids: mild disease, area-limited
- Phototherapy (NB-UVB): time burden, access constraints
- Methotrexate, cyclosporine: immunosuppression + long-term toxicity
- Biologics (TNF-α, IL-17, IL-23 inhibitors): powerful but injectable + cost + immunogenicity
- Deucravacitinib (Sotyktu, 2022): first oral TYK2. ~50% PASI 75 at week 16
Zasocitinib’s impact:
- Oral once-daily, not injected
- Biologic-comparable efficacy
- Superior side effect profile (TYK2-selective)
- Sustained response (60-week 90%+)
- Likely lower cost than biologics
What “PASI 100 of 30%” Means
Existing biologic week-16 PASI 100 rates:
- Secukinumab (IL-17): ~28%
- Ixekizumab (IL-17): ~39%
- Risankizumab (IL-23): ~36%
- Deucravacitinib (TYK2 1st gen): ~14%
- Zasocitinib (TYK2 next gen): ~30%
Zasocitinib’s ~30% PASI 100 is essentially equivalent to IL-17/IL-23 biologics. Biologic efficacy in oral form is the key impact.
Clinical Application
- Likely indication: 18+ moderate-to-severe plaque psoriasis (PASI 12+, BSA 10%+)
- Dose: once-daily oral (exact dose pending labeling)
- Time to effect: week 4 first response, week 16 primary, weeks 24-60 cumulative deepening
- Monitoring: liver function, lipids, blood counts, TB and hepatitis B screening
- Contraindications: active TB, hepatitis B, pregnancy
- Side effects: upper respiratory infection, acneiform eruption, herpes reactivation. No MACE signal observed
- Patient selection: phototherapy non-responders, injection-averse patients, biologic-naive
- Combinations: topical corticosteroids OK; not co-administered with biologics
- Pregnancy planning: effective contraception required; 6-month washout suggested