Shattuck Labs, Inc. to file the previously-announced initial topline dose-expansion data from its ongoing Phase 1A/B clinical trial of SL-172154 in combination with AZA in frontline HR-MDS and TP53m AML patients. Phase 1B Trial of SL-172154 in Frontline TP53m AML and HR-MDS: In 11 evaluable patients with previously untreated TP53m AML, two patients achieved a CR. Another patient achieved a CRi and was taken to allogeneic hematopoietic cell transplantation (allo-HCT).

Phase 1A Trial of SL-172154 In R/R AML and HR-M DS and Frontline TP53m HR-MDS. Key takeaways: Anti-tumor responses were observed as monotherapy and in combination with AZA. SL-172154 alone and in combination with AZA had an acceptable safety profile, consistent with the safety profile of the individual agents.

No destructive anemia was observed. Data Overview: As of the data cut-off date of September 15, 2023, 32 adult patients with R/R AML andHR-MDS received SL-172154 as monotherapy or in combination with AZA in the parallel staggered dose-escalation portion of a Phase 1A/B clinical trials. Patients had a median of two prior lines of therapy.

An additional five subjects with frontline TP53m HR-M DS received SL-172154 with AZA. Preliminary signs of anti-tumor activity: Monotherapy response in a R/R AML patient and early signals of anti-leukemic activity (in the form of blast count reductions) in patients with R/R AM L who received SL-172154 in combination With AZA were observed in a dose-dependent manner. Out of four evaluable previously untreated TP53m HR-MDA patients, there was one CR and one mCR.

One patient with mCR and one patient with SD proceeded to allo-HCT. The patient in a CR remains in a CR long term.