The New WIZ-Kid in Protein Degradation

Why It Matters

Elevating HbF to ~30% of total hemoglobin can essentially cure SCD symptoms, positioning molecular‑glue degraders as a potential first‑in‑class therapy that could reshape the hemoglobin disorder market.

Key Takeaways

• WIZ/ZBTB7A degradation boosts fetal hemoglobin levels.
• Novartis' NVP‑ITU512 in Phase 1/2 for SCD.
• BMS‑986470 targets both WIZ and ZBTB7A, also Phase 1/2.
• ~30% HbF target could fully alleviate SCD symptoms.
• GluBio Tx and Harvard SH‑6 broaden degrader landscape.

Pulse Analysis

Targeted protein degradation (TPD) has moved beyond oncology into hematology, where transcription factors WIZ and ZBTB7A act as gatekeepers of γ‑globin repression. By chemically linking these proteins to the cereblon E3 ligase, molecular glues trigger their ubiquitination and clearance, reactivating fetal hemoglobin production. HbF interferes with sickle hemoglobin polymerization, and clinical data suggest that achieving roughly 30% HbF can virtually eliminate vaso‑occlusive crises, making TPD a compelling disease‑modifying approach for both sickle cell disease and β‑thalassemia.

Novartis and Bristol‑Myers Squibb are leading the clinical translation of this concept. Novartis' undisclosed clinical asset, NVP‑ITU512, emerged from a series of CRBN‑dependent glue degraders detailed in a 2024 patent and subsequent Science paper, and it is now enrolling patients in a Phase 1/2 study (NCT06546670). BMS leveraged its CELMoD platform to discover BMS‑986470, a dual degrader that eliminates both WIZ and ZBTB7A while avoiding classic off‑targets such as CK1α and Ikaros; it is also in Phase 1/2 (NCT06481306). Both programs emphasize selectivity and metabolic stability, addressing earlier concerns about off‑target immunomodulation that hampered first‑generation IMiDs.

The competitive field is widening. Chinese biotech GluBio Tx claims selective and dual degraders (GLB‑005, GLB‑007), and a Harvard‑led consortium recently reported SH‑6, a non‑IMiD CRBN degrader of ZBTB7A. As multiple candidates converge on the same therapeutic endpoint, the market could see a rapid influx of first‑in‑class agents, potentially driving down costs and expanding access. Successful Phase 1/2 readouts would likely trigger accelerated regulatory pathways, given the high unmet need, and could set a precedent for applying TPD to other transcription‑factor‑driven diseases.