Cyclacel to Receive New European Patent for Plogosertib Compositions

Cyclacel Pharmaceuticals, Inc., a company focused on developing innovative treatments derived from cancer cell biology, has recently received significant news from the European Patent Office. This announcement revealed the office's intention to grant a patent for novel pharmaceutical formulations of plogosertib, a Polo-like kinase 1 (PLK1) inhibitor. The granted patent will ensure exclusivity for these formulations in Europe until August 2040, excluding potential extensions. Cyclacel is also pursuing additional patent applications for plogosertib in other regions.

Spiro Rombotis, Cyclacel's President and CEO, emphasized that this notice highlights the novelty of their clinical pipeline, which includes in-house discoveries like plogosertib and fadraciclib. The patent will bolster the company's shift to a new and more bioavailable oral formulation of plogosertib. Cyclacel's strategy involves testing plogosertib in clinical settings to determine its effectiveness against cancers with ARID1A and/or SMARCA mutations. Alongside plogosertib, Cyclacel is advancing fadraciclib, a CDK2/9 inhibitor, in clinical trials. These trials initially target patients with solid tumors selected for CDKN2A/CDKN2B alterations, followed by those with T-cell lymphoma. Preliminary data from these trials are expected in the latter half of 2024.

Polo-like kinase 1 (PLK1) is a critical serine/threonine kinase involved in cell division and regulation of the DNA damage cell cycle checkpoint. PLK1 is essential for processes such as mitotic entry and exit, spindle formation, and cytokinesis. Cancer cells, particularly those with KRAS mutations and p53 deficiencies, are highly susceptible to PLK1 depletion. Inhibiting PLK1 pharmacologically can halt cancer cell proliferation by inducing prolonged mitotic arrest and triggering apoptotic cell death. In contrast, normal cells with intact cell cycle checkpoints exhibit less sensitivity to PLK1 inhibition.

Plogosertib, previously known as CYC140, is a novel, selective, and potent small molecule PLK1 inhibitor. It has demonstrated significant efficacy in human tumor xenografts at non-toxic doses. Cyclacel's translational biology program is advancing plogosertib for use in solid tumors and leukemias. Preclinical studies by independent research groups have indicated that cancers with ARID1A and/or SMARCA mutations might respond well to plogosertib treatment. Furthermore, recent data suggest that PLK1 inhibition could be beneficial for patients with KRAS-mutated metastatic colorectal cancer. High levels of PLK1 expression are associated with poor prognosis in various cancers, including esophageal, gastric, leukemia, lung, ovarian, and MYC-amplified cancers.

Initial findings from a Phase 1 clinical trial of oral plogosertib indicate that the compound is well tolerated, with no dose-limiting toxicities observed across five dosing schedules. Clinical benefits were noted in patients with adenoid cystic carcinoma, biliary tract cancer, ovarian cancer, and squamous cell sinus cancer.

Cyclacel Pharmaceuticals, Inc. is a clinical-stage biopharmaceutical company committed to developing innovative cancer treatments focusing on cell cycle, transcriptional regulation, and mitosis biology. The company's programs are centered on fadraciclib, a CDK2/9 inhibitor, and plogosertib, a PLK1 inhibitor, targeting both solid tumors and hematological malignancies. Cyclacel's overarching goal is to create a diversified biopharmaceutical portfolio addressing oncology and hematology needs.

Thus, the new patent notice for plogosertib marks a significant milestone for Cyclacel, reinforcing its dedication to pioneering cancer biology-based treatments. The company's focused efforts on advancing plogosertib and fadraciclib demonstrate its commitment to addressing critical areas in cancer therapy.