Enliven Reports Positive Initial Phase 1b Data for ELVN-001 in CML and Outlines 2026 Clinical Milestones

On January 8, 2026 Enliven Therapeutics, Inc. (Enliven or the Company) (Nasdaq: ELVN), a clinical-stage biopharmaceutical company focused on the discovery and development of small molecule therapeutics, reported positive initial data from the ongoing Phase 1b ENABLE clinical trial evaluating ELVN-001 in patients with chronic myeloid leukemia (CML) that is relapsed, refractory or intolerant to available tyrosine kinase inhibitors (TKIs) (NCT05304377).

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"We are excited about these initial Phase 1b data, the progress we made throughout 2025 and the year ahead. Our data continue to demonstrate that ELVN-001 has the potential to be the best-in-class active-site TKI for the treatment of CML and an important treatment option across all lines of therapy," said Helen Collins, M.D., Chief Medical Officer of Enliven. "Momentum has been building over the last year leading to significant interest in our Phase 3 clinical trial from sites all around the world. We are preparing for upcoming regulatory interactions with the FDA to align on dose selection and support initiation of the Phase 3 trial in the second half of 2026."

ELVN-001 Program Updates

ELVN-001 is a potent, highly selective, potentially best-in-class small molecule kinase inhibitor designed to specifically target the BCR::ABL gene fusion, the oncogenic driver for patients with CML.

Encouraging ELVN-001 Phase 1b Data by 24 Weeks

As of the cutoff date of December 22, 2025, 60 patients were enrolled in the initial cohorts of the Phase 1b trial. Patients were first enrolled in the 80 mg once daily (QD) cohort. Subsequent patients were randomized to either 60 mg QD or 120 mg QD.
Patients enrolled were heavily pretreated, consistent with patients from previously reported datasets. In these 60 patients:
53% of patients received four or more unique prior TKIs.
67% of patients received prior asciminib and 32% received prior ponatinib.
Despite the heavily pretreated patient population, the efficacy data below highlights that ELVN-001 continues to demonstrate the profile of a best-in-class active-site TKI.
Dose (number of patients)

80 mg QD (n=19)

60/120 mg QD (n=41)

Cumulative MMR

47% (n=19)

69% (n=26)

Achieved MMR

38% (n=16)

53% (n=17)

Maintained MMR

100% (n=3)

100% (n=9)

Deep Molecular Response (DMR)

16% (n=19)

35% (n=26)

As of the data cutoff in December:

In the 80 mg QD Phase 1b cohort (n=19), all patients were evaluable for efficacy by 24 weeks. In these mature data, rates of MMR achievement (38%) and DMR (16%) compare favorably to precedent Phase 1 trials of approved BCR::ABL1 TKIs, including asciminib.
In the randomized 60 mg and 120 mg cohorts (n=41), 26 patients were evaluable for efficacy by 24 weeks, reflecting their more recent enrollment. In this cohort, highly encouraging rates of MMR achievement (53%) and DMR (35%) were observed.
Across all Phase 1b cohorts, 100% of evaluable patients in MMR at enrollment maintained, or deepened, their response.
As expected, robust clinical activity was observed at doses from 60 mg to 120 mg QD, with no clear evidence of dose response (efficacy or safety) within this range.
ELVN-001 continues to demonstrate a favorable safety and tolerability profile across all evaluated doses. The safety profile observed in these Phase 1b cohorts remained consistent with previously reported data, with no maximum tolerated dose and no new safety signals identified.
Expected 2026 Clinical Milestones for ELVN-001

Mid-year presentation of additional Phase 1 data from the ongoing ENABLE trial
Regulatory alignment with the FDA on dose selection and Phase 3 trial design
Initiation of ENABLE-2, the Phase 3 clinical trial of ELVN-001, in the second half of 2026
About the ENABLE Trial
The ENABLE study (NCT05304377) is a Phase 1 study of ELVN-001 in patients with previously treated CML. ENABLE is a dose escalation and expansion trial designed to evaluate safety and tolerability and to determine the recommended dose for further clinical evaluation of ELVN-001 in patients with CML with and without T315I mutations that is relapsed, refractory or intolerant to TKIs. Secondary endpoints include pharmacokinetics, MMR by central quantitative reverse transcriptase polymerase chain reaction, duration of MMR, BCR::ABL1 transcript levels and complete hematologic response.

About ELVN-001
ELVN-001 is a potent, highly selective, potentially best-in-class small molecule kinase inhibitor designed to specifically target the BCR::ABL gene fusion, the oncogenic driver for patients with chronic myeloid leukemia. As a highly selective active-site TKI, ELVN-001 has a mechanism of action that is complementary to allosteric BCR::ABL1 inhibitors, which may play an increasingly important role in the standard of care. ELVN-001 was also designed to have activity against the T315I mutation, the most common BCR::ABL1 mutation, which confers resistance to nearly all approved TKIs, as well as activity against mutations known to confer resistance to allosteric BCR::ABL1 inhibitors.

(Press release, Enliven Therapeutics, JAN 8, 2026, View Source [SID1234661870])