Company: KROS
Filing Date: 2025-02-26
Form Type: 10-K
Source: 0001664710-25-000018
Chunk: 116

Company: Keros Therapeutics, Inc.
Filing Date: 2025-02-26
Form: 10-K
Item: Item 1
Chunk 116
---
1, eligible patients were given the opportunity to escalate up to the RP2D and receive long-term treatment with elritercept for up to an additional 20 cycles, which we refer to as the Part 1 Extension.

In December 2024, we presented additional data from this ongoing trial at the 66th American Society of Hematology, or ASH, Annual Meeting and Exposition. As of August 30, 2024, which was the data cut-off date, 95 patients had received at least one dose of elritercept at RP2D, which we refer to as the safety population. 87 of these patients had completed at least 24 weeks of treatment or discontinued as of the data cut-off date, which we refer to as the mITT24 patients. Data for hematological response and markers of hematopoiesis were presented from exploratory analyses of these mITT24 patients. 

Of the 95 patients in the safety population, 60.0% (n=57) had high transfusion burden, or HTB, while 24.2% (n=23) had low transfusion burden, or LTB, and 15.8% (n=15) were non-transfused, or NT. 

Elritercept was generally well tolerated as of the data cut-off date. There were four cases of fatal treatment-emergent adverse events, or TEAEs, in the trial that were all determined to be unrelated to treatment. The most commonly reported TEAEs (in ≥15% of patients) were diarrhea, fatigue, COVID-19, dyspnea, dizziness, anemia, nausea and epistaxis. One patient had progressed to acute myeloid leukemia as of the data cutoff date.

As of the data cut-off date, 55.2% (n=48/87) of the mITT24 patients achieved an overall erythroid response over the first 24 weeks of treatment, which is defined as meeting either modified International Working Group 2006 Hematological improvement-erythroid, or HI-E, or transfusion independence, or TI, for at least eight weeks in transfusion-dependent patients who required ≥ 2 red blood cell units transfused at baseline. The median duration of transfusion independence was 134.1 weeks. Due to ongoing TI responses as of the data cutoff date, the median duration of TI is expected to change as data continues to accumulate. 48.1% (n=13/