BEIJING,SHANGHAI and BOSTON,Dec. 9,2024 -- Jacobio Pharma (1167.HK),a clinical-stage oncology company dedicated to developing therapies toward undruggable targets,today presented preliminary Phase I data of BET inhibitor JAB-8263 to treat myelofibrosis (MF) at the 2024 ASH (American Society of Hematology) Annual Meeting in San Diego,California.

The data showed that JAB-8263 was well tolerated with Recommended Phase 2 Dose (RP2D) being 0.3mg QD. The preliminary efficacy data for JAB-8263 monotherapy in MF are promising,as most patients demonstrated spleen volume reduction (SVR) and total symptom score (TSS) reduction.

As of the data cutoff date of Oct 17,2024,16 patients with intermediate-/high-risk MF have been enrolled,and 13 patients have undergone at least one post-treatment efficacy assessment.

All patients showed a mean SVR-19.95%at week 24 and -26.16% at best response.

Two patients achieved ≥35% SVR,and an SVR of -34.9% was observed in one patient.

Six of ten (60%) patients experienced a ≥50% reduction in TSS at week 24.

The best response of SVR in 2 of 8 patients (JAK inhibitors-treated) was -41.2% and -34.9%,respectively.

At week 24,3 of 6 (50%) patients (JAK inhibitors-treated) achieved TSS50.

The monotherapy of JAB-8263 expansion in MF and solid tumor is ongoing.Andrea Wang-Gillam M.D.,Ph.D.,Chief Medical Officer and Global Head of R&D at Jacobio said,"The preliminarydata demonstrated the promising clinical value of our potent BET inhibitor in MF. We will continue exploring forbroader indications for JAB-8263,hoping to bring hope to more cancer patients."

About Jacobio

Jacobio Pharma (1167.HK) is committed to developing and providing new and innovative products and solutions. Our pipeline revolves around novel molecular targets on six major signaling pathways: KRAS,immune checkpoints,tumor metabolism,P53,RB and MYC. We aim for our key projects to be among the top three in the world. Our vision is to become a global leader recognized for our impact in drug R&D together with our partners. Jacobio has R&D centers in Beijing,Shanghai and Boston with our Induced Allosteric Drug Discovery Platform (IADDP) and our iADC Platform.