Company: KROS
Filing Date: 2025-02-26
Form Type: 10-K
Source: 0001664710-25-000018
Chunk: 120

Company: Keros Therapeutics, Inc.
Filing Date: 2025-02-26
Form: 10-K
Item: Item 1
Chunk 120
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62.5% (n=10/16) had reductions of 50% or greater, and 37.5% (n=6/16) achieved TI.

•At week 24, reduction in spleen volume was observed in 40% (n=8/20) of patients with baseline spleen size ≥ 450 cm3 and a week 24 spleen assessment, including three patients who had reductions of 35% or greater. Reductions in spleen volume in the combination arm generally occurred without an increase in ruxolitinib dose.

◦For evaluable patients in the combination arm with a starting dose of 3.0 mg/kg of elritercept or higher, 88% (n=7/8) had some reduction in spleen size at week 24.

•At week 24, reduction in disease symptoms was observed in 66.7% (n=18/27) of patients with at least two symptoms with an average score ≥ 3 or an average total score of ≥ 10 on the MF-SAF-TSS questionnaire at baseline and a week 24 MF-SAF-TSS assessment. Five patients had reductions of at least 50%, including three in the monotherapy arm and two in the combination arm.

25

The data support the potential of elritercept to ameliorate ineffective hematopoiesis and address cytopenias due to myelofibrosis and associated with ruxolitinib, and provide broader clinical benefit in patients, as supported by the observed reduction in spleen volume and improvement in total symptom scores. 

Completed Phase 1 Clinical Trial

In January 2020, we completed a randomized, double-blind, placebo-controlled, two-part, dose-escalation Phase 1 clinical trial of elritercept in 48 healthy post-menopausal women. The primary objectives of this trial were safety, tolerability and pharmacokinetics. We also investigated changes in hematology and bone biomarkers in this clinical trial.

In Part 1 of this trial, 30 subjects received a single dose of elritercept and eight subjects received a single dose of placebo, each administered subcutaneously with a 12-week safety follow-up. The subjects were enrolled in sequential single-ascending dose escalation cohorts of up to ten subjects each. In Part 2 of this trial, eight subjects received elritercept and two received placebo, administered subcutaneously, on two occasions 28 days apart, with a 12-week safety follow