18 October 2021 - - Switzerland-based biopharmaceutical company Rhizen Pharmaceuticals AG has commenced dosing in a phase II trial to evaluate Tenalisib (RP6530; isoform selective dual PI3K δ/γ inhibitor with additional SIK3 activity) in patients with locally advanced or metastatic breast cancer, the company said.

This multi-center, randomized phase II study is being conducted in eastern Europe and is designed to assess Tenalisib's anti-tumor activity and safety across two dose levels. 

The study also includes translational assessments intended to delineate the effect of Tenalisib's multivalent mechanism on relevant cytokines/chemokine levels and gene expression changes within the tumor microenvironment.

Rhizen indicated that Tenalisib, in addition to its selective dual PI3K δ/γ inhibitory activity, also has Salt-Inducible Kinase 3 activity via its principal metabolite, that could potentially contribute to its chemo-sensitization effect as observed in its preclinical studies, especially in breast cancer.

Rhizen hopes to establish the single agent activity of Tenalisib in this current study after which it plans to expand the assessment across additional solid tumor indications and combinations both with chemotherapeutic agents and with immune-checkpoint inhibitors.

Tenalisib (RP6530) is a highly selective, next-generation, orally active, dual PI3K δ/γ inhibitor with additional SIK3 activity, that is currently in phase II clinical development for haematological malignancies and solid tumors.

Tenalisib has been granted US FDA Fast Track and Orphan-Drug Designations for treatment of r/r PTCL and CTCL and had recently published data from its phase II study evaluating Tenalisib both as monotherapy and in combination with Romidepsin in r/r PTCL and CTCL which showed robust responses of ~75% ORR in r/r PTCL and ~54% in r/r CTCL.

The combination was well tolerated with no additional toxicities noted over and above those of the individual agents, confirming Tenalisib's superior safety profile in its class.

Overall, Tenalisib has been studied in over 165 patients across studies till now and has shown potentially better safety outcomes vis-à-vis other agents in the PI3K class.

Rhizen Pharmaceuticals is a clinical-stage biopharmaceutical company focused on the discovery and development of novel oncology and inflammation therapeutics.

Since its establishment in 2008, Rhizen has created a diverse pipeline of proprietary drug candidates targeting several cancers and immune associated cellular pathways.

Rhizen has proven expertise in the PI3K modulator space with the discovery of our first PI3Kδ and CK1ε asset Umbralisib, that has been successfully developed and commercialized in MZL and FL by our licensing partner TG Therapeutics in USA.

Beyond this, Rhizen has a deep oncology and inflammation pipeline spanning discovery to phase II clinical development stages.

Rhizen is headquartered in Basel, Switzerland.