Pacylex Publishes Phase 1 Safety and Efficacy of Zelenirstat in Cancer Patients in the Journal Investigational New Drugs

June 10, 2024 9:27 AM EDT | Source: Reportable, Inc.

Edmonton, Alberta--(Newsfile Corp. - June 10, 2024) - Pacylex Pharmaceuticals Inc. (Pacylex) is a clinical-stage pharmaceutical company developing N-myristoyltransferase (NMT) inhibitors to treat hematologic cancers and solid tumors. Today Pacylex announced the publication of Phase 1 clinical trial results in the journal Investigational New Drugs. The report, titled: "A First-in-Human Phase I Trial of Daily Oral Zelenirstat, a N-myristoyltransferase Inhibitor, in Patients with Advanced Solid Tumors and Relapsed/Refractory B-cell Lymphomas," describes effects of zelenirstat at various doses on cancer patients who exhausted all other therapeutic options.

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Key Takeaways:

  • Zelenirstat was well tolerated, and adverse events were primarily gastrointestinal side effects, most of which resolved spontaneously without dose reduction.
  • Patients with heavily pre-treated colorectal, appendiceal, and ovarian cancers had 6 to 16 months of stable disease when treated with the recommended Phase 2 dose.
  • Zelenirstat inhibits myristoylation of proteins involved in several key cancer-driving processes explaining its broad spectrum of activity.

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About Zelenirstat (PCLX-001)

Zelenirstat (formerly identified as PCLX-001) is a first-in-class, oral, small molecule NMTi being developed to treat patients with leukemia, lymphoma, and solid tumors. Zelenirstat selectively killed cancer cells in vitro and in animal models has been shown to fully regress hematologic malignancies and inhibit the growth of lung and breast cancer tumors. In AML models, zelenirstat preferentially killed leukemic stem enriched cell populations and reduced the bone marrow leukemic burden. 

About Zelenirstat Phase 1 and 2 Studies 

Pacylex completed the dose escalation phase of a Phase 1 multiple ascending dose safety, tolerability, and pharmacokinetics study on zelenirstat in people with relapsed/refractory lymphoma and refractory solid tumors (NCT04836195). A recommended Phase 2 dose was determined. Zelenirstat demonstrated an acceptable safety and tolerability profile, pharmacokinetics consistent with once daily oral dosing, and early signs of efficacy.

Zelenirstat is currently being studied in a Phase 2a open-label study designed to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics, and clinical activity of zelenirstat in patients with relapsed/refractory B-cell non-Hodgkin Lymphoma (NHL) and a separate Phase 2a cohort in patients with refractory metastatic colorectal cancer that has progressed despite all available standard therapies. 

About Pacylex Pharmaceuticals

Pacylex is a clinical-stage pharmaceutical company headquartered in Edmonton, Alberta, Canada, targeting hematologic and solid cancers with orally bioavailable NMT inhibitors. Zelenirstat is the lead drug in a new class of NMT inhibitors, enabling Pacylex to exploit NMTs as new clinical targets for cancer treatment. Pacylex is conducting two multi-center Phase 2a studies in Canada in patients with relapsed/refractory NHL and refractory metastatic colorectal cancer. The IND for a Phase 1 multiple ascending dose study in acute myeloid leukemia (AML) has been cleared and the FDA has granted zelenirstat both Orphan Drug Designation and Fast Track Designation for AML. The US Department of Defense is supporting the initial clinical investigation of zelenirstat in patients with AML. The Cure Cancer Foundation supported initial clinical studies through its World's Longest Games. 


Michael Weickert Ph.D

Source: Pacylex

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