Jubilant Therapeutics Announces Oral Presentation of Preliminary Phase 1 Clinical Data for JBI-802, a First-in-Class Oral Dual LSD1/HDAC6 Inhibitor, in Essential Thrombocythemia and Related Myeloproliferative Neoplasms at the 68th ASH Annual Meeting

• Abstract data show rapid platelet reductions and durable hematologic control
• Company to host an event on December 14, 2026

YARDLEY, Pa., Nov. 10, 2026 /PRNewswire/ -- Jubilant Therapeutics, Inc., a clinical-stage biopharmaceutical company, advancing precision therapeutics for myeloproliferative neoplasms (MPNs), today announced that clinical results from its Phase 1/2 study of JBI-802, a first-in-class, orally administered dual inhibitor of LSD1 and HDAC6 (CoREST), have been selected for an oral presentation at the 68th American Society of Hematology (ASH) Annual Meeting and Exposition, taking place December 12–15, 2026, in New Orleans and online.

"We are pleased to have the preliminary clinical data for JBI-802 selected for oral presentation at ASH," said Daniel O'Connor, President and Chief Executive Officer of Jubilant Therapeutics. "The abstract data from this ongoing Phase 1/2 study show encouraging early evidence of rapid platelet reductions and hematologic control in patients with ET and related MPNs. We look forward to presenting additional efficacy, safety and molecular data at ASH as we continue to evaluate JBI-802 in these patients."

The oral presentation will include results from the Phase 1 portion of the study, an open-label, multicenter trial designed to evaluate the safety, tolerability and preliminary efficacy of JBI-802. The study has enrolled patients with essential thrombocythemia (ET), polycythemia vera (PV) and myelodysplastic/myeloproliferative neoplasms (MDS/MPN) with thrombocytosis who were relapsed, refractory or intolerant to standard of care (JBI-802-02; ACTRN12624000478516).

Key findings from the abstract (data as of June 30, 2026) include:

• All 8 patients who initiated treatment at the 15 mg achieved a >50% platelet reduction or platelet normalization (<400 ×10⁹/L) by Week 3, with a median time to response of 15 days.
• Platelet normalization was maintained through 33, 44 and 46 weeks in patients enrolled at 15 mg with >12 weeks of follow-up.
• Seven of 11 patients with leukocytosis at 15 mg achieved a complete hematologic response.
• No dose-limiting toxicities were observed at 5, 7 or 15 mg.

Additional efficacy, safety and molecular data will be presented during the oral session. The abstract is available on the ASH Annual Meeting website.

Details of the ASH Presentations

Scientific and Corporate Event

Jubilant will host Dual LSD1/HDAC6 Inhibition with JBI-802 in Thrombocytosis-Predominant MPN: Clinical Data and Emerging Perspectives on December 14, 2026, following the oral presentation by Dr. Andrew McQuillan, MBBS, FRACP, FRCPA, at 5:15PM CT/ 6:15PM ET. The event will review the Phase 1 data presented at ASH and discuss their clinical implications. The event will be livestreamed, and a replay will be available on the Company's website. Details of the event will be forthcoming. The presentations will be posted in the Publications section of www.jubilanttx.com following the sessions.

About JBI-802

JBI-802 is an orally administered dual inhibitor of lysine-specific demethylase 1 (LSD1) and histone deacetylase 6 (HDAC6) that targets the CoREST complex. It is designed to act on multiple disease-relevant processes, including abnormal megakaryocyte differentiation, platelet production, leukocyte proliferation and inflammatory signaling. JBI-802 is being evaluated in an ongoing Phase 1/2 study in patients with ET and other thrombocytosis-predominant myeloid malignancies (JBI-802-02; ACTRN12624000478516; NCT07612280).

About Jubilant Therapeutics

Jubilant Therapeutics is a clinical-stage biopharmaceutical company advancing precision therapeutics for myeloproliferative neoplasms. The Company leverages deep expertise in medicinal chemistry, structure-based drug design, translational science and clinical development to discover and develop differentiated small-molecule medicines for significant unmet medical needs. Its lead clinical asset, JBI-802, is a first-in-class dual LSD1/HDAC6 (CoREST) inhibitor being evaluated in ET, MPN and other indications. Its pipeline also includes JBI-3041, a selective first-in-class PAD4 inhibitor with potential applications across autoimmune diseases. Headquartered in Yardley, Pennsylvania, Jubilant Therapeutics is committed to delivering innovative therapies that improve outcomes for patients worldwide. Jubilant Therapeutics Inc. is a step down subsidiary of Jubilant Pharmova Limited.

For more information, visit www.jubilanttx.com or follow the Company on X (@JubilantTx) and LinkedIn.

Forward-Looking Statements

This press release contains forward-looking statements, including statements regarding the clinical development of JBI-802, the timing and content of data presentations, and the potential of JBI-802 to address unmet needs in ET and related MPNs. These statements are based on current expectations and are subject to risks and uncertainties that could cause actual results to differ materially, including risks related to clinical development, the preliminary nature of early-phase data from a small number of patients, regulatory review and the Company's ability to execute on its plans. Jubilant Therapeutics undertakes no obligation to update any forward-looking statement except as required by law.

SOURCE Jubilant Therapeutics