Tolero Pharmaceuticals to Present Clinical Data Evaluating Investigational Agent Alvocidib in Patients with Relapsed Refractory MCL-1 dependent AML at EHA 2018

SALT LAKE CITY, May 18, 2018 /PRNewswire/ -- Tolero Pharmaceuticals, Inc., a clinical-stage company focused on developing novel therapeutics for hematological and oncological diseases, today announced the presentation of preliminary data from Zella201, an ongoing Phase 2 study evaluating the efficacy and safety of alvocidib, a potent CDK9 inhibitor, in combination with cytarabine and mitoxantrone in patients with relapsed or refractory MCL-1-dependent acute myeloid leukemia (AML). These findings will be presented at the 23^rd Annual Congress of the European Hematology Association (EHA) taking place June 14-17, 2018, in Stockholm, Sweden.

"We are encouraged by the activity seen in the ongoing Zella201 study and the growing body of scientific evidence supporting the potential of alvocidib in patients with this type of AML, where there are limited treatment options," said David J. Bearss, Ph.D., Chief Executive Officer of Tolero Pharmaceuticals. "We look forward to sharing findings from this study at the upcoming EHA congress."

Below are the details for the poster presentation:

About Alvocidib
Alvocidib is an investigational small molecule inhibitor of cyclin-dependent kinase 9 (CDK9) currently being evaluated in a Phase II study in patients with relapsed or refractory MCL-1 dependent acute myeloid leukemia, AML, in combination with cytarabine and mitoxantrone (NCT02520011). Alvocidib is also being evaluated in Zella101, a Phase I clinical study evaluating the maximum tolerated dose, safety and clinical activity of alvocidib in combination with (7+3) in newly diagnosed patients with AML (NCT03298984).

About CDK9 Inhibition and MCL-1
MCL-1 is a member of the apoptosis-regulating BCL-2 family of proteins.¹ In normal function, it is essential for early embryonic development and for the survival of multiple cell lineages, including lymphocytes and hematopoietic stem cells.² In MCL-1?dependent AML, MCL-1 inhibits apoptosis and sustains the survival of leukemic blasts, which may lead to relapse or resistance to treatment.^1,3 The expression of MCL-1 in leukemic blasts is regulated by cyclin-dependent kinase 9 (CDK9).^4,5 Because of the short half-life of MCL-1 (2-4 hours), the effects of targeting upstream pathways are expected to reduce MCL-1 levels rapidly.⁴ Inhibition of CDK9 has been shown to block MCL-1 transcription, resulting in the rapid downregulation of MCL-1 protein, thus restoring the normal apoptotic regulation.¹

About Tolero Pharmaceuticals, Inc.
Tolero Pharmaceuticals is a clinical-stage biopharmaceutical company researching and developing treatments to improve and extend the lives of patients with oncological and hematological diseases. Our diverse pipeline targets important biological drivers of blood disorders to treat leukemias, anemia, and solid tumors, as well as targets of drug resistance and transcriptional control. Tolero Pharmaceuticals is based in the United States and is an indirect, wholly-owned subsidiary of Sumitomo Dainippon Pharma Co., Ltd., a pharmaceutical company based in Japan.

Additional information about the company and its product pipeline can be found at www.toleropharma.com.

Tolero Pharmaceuticals Forward-Looking Statements
This press release contains "forward-looking statements", as that term is defined in the Private Securities Litigation Reform Act of 1995 regarding the research, development and commercialization of pharmaceutical products.  The forward-looking statements in this press release are based on management's assumptions and beliefs in light of information presently available, and involve both known and unknown risks and uncertainties, which could cause actual outcomes to differ materially from current expectations. Any forward-looking statements set forth in this press release speak only as of the date of this press release. We do not undertake to update any of these forward-looking statements to reflect events or circumstances that occur after the date hereof. Information concerning pharmaceuticals (including compounds under development) contained within this material is not intended as advertising or medical advice.

¹ Thomas D, Powell JA, Vergez F, et al. Targeting acute myeloid leukemia by dual inhibition of PI3K signaling and Cdk9-mediated Mcl-1 transcription. Blood. 2013;122(5):738-748.
² Perciavalle RM, Opferman JT. Delving deeper: MCL-1's contributions to normal and cancer biology. Trends Cell Biol. 2013;23(1):22-29.
³ Glaser SP, Lee EF, Trounson E, et al. Anti-apoptotic Mcl-1 is essential for the development and sustained growth of acute myeloid leukemia. Genes Dev. 2012;26(2):120-125.
⁴ Chen R, Keating MJ, Gandhi V, Plunkett W. Transcription inhibition by flavopiridol: mechanism of chronic lymphocytic leukemia cell death. Blood. 2005;106(7):2513-2519.
⁵ Ocana A, Pandiella A. Targeting oncogenic vulnerabilities in triple negative breast cancer: biological bases and ongoing clinical studies. Oncotarget. 2017;8(13):22218-22234.

SOURCE Tolero Pharmaceuticals, Inc.