Company: KROS
Filing Date: 2025-02-26
Form Type: 10-K
Source: 0001664710-25-000018
Chunk: 112

Company: Keros Therapeutics, Inc.
Filing Date: 2025-02-26
Form: 10-K
Item: Item 1
Chunk 112
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 specialized function. The elritercept-mediated inhibition of these regulators has been shown in preclinical studies to stimulate the progenitors to progress to maturation and, consequently, increase the number of mature cells in the blood. 

Data from our Phase 1 clinical trial in healthy volunteers and our two ongoing Phase 2 clinical trials, one in patients with MDS and one in patients with myelofibrosis, also demonstrate that treatment with elritercept increased red blood cell and platelet production. These data indicate that elritercept is differentiated from available therapies because it appears to have both sustained and rapid effects on multiple cellular lineages in the hematopoietic pathway. We believe elritercept’s promotion of differentiation of early- and terminal-stage progenitor cells contributes to these sustained and rapid effects, respectively, and consequently, elritercept may be effective for many patients that are refractory to available therapies and may potentially provide benefit in multiple cytopenias simultaneously.

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Mechanism of Action of Elritercept

Consistent with our preclinical studies, which showed improvement in bone health, we observed an increase in bone-specific alkaline phosphatase, a biomarker of bone remodeling, in our Phase 1 clinical trial in healthy volunteers and our ongoing Phase 2 clinical trial in patients with MDS, following administration of elritercept. Based on these data, we believe elritercept also has the potential to regenerate a healthy bone marrow and slow disease progression.

Separately, in a preclinical study in wild type mice, treatment with ruxolitinib resulted in reductions in red blood cells, hemoglobin and hematocrit, recapitulating the anemia observed in myelofibrosis patients. Administration of RKER-050, a mouse version of elritercept, reversed the observed ruxolitinib-associated reductions in the red blood cell parameters, which we believe supports the potential of elritercept to mitigate the dose-limiting effects of ruxolitinib and enhance the duration of therapy in myelofibrosis patients.

We intend to develop elritercept for the treatment of both MDS- and myelofibrosis-associated cytopenias. We believe elritercept has the potential to overcome limitations of current treatment options for MDS- and myelofibrosis-associated cytopenias. We believe the potential advantages of elritercept compared to current treatment options include:

•Dual mechanism affecting both the early and terminal stages of erythropoiesis. Patients with MDS can have defects occurring