BASEL, SWITZERLAND-- May 06, 2022 -- Rhizen Pharmaceuticals AG (Rhizen), a Switzerland-based privately held, clinical-stage biopharmaceutical company announced today that it is presenting promising interim data from an ongoing Ph2 trial of Tenalisib in locally advanced or metastatic breast cancer patients, at the ESMO Breast Cancer Meeting, in Berlin, Germany from May 3-5, 2022.

This multi-center, randomized phase II study is being conducted in eastern Europe and is designed to assess Tenalisib‘s anti-tumor activity (clinical benefit rate at the end of 6 months, disease control rate and overall response rates) 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.

The study included 40 enrolled patients (39 HR+/Her2- and 1 TNBC) presenting with stage IV A or IV B advanced or metastatic disease with majority of the patients having significant distal metastases to the bone, lymph nodes, lung and liver. The study population included patients with both primary resistance (~40%) and secondary resistance (~60%) to endocrine therapy and with ~50% of the patients undergoing prior chemotherapy treatment in a metastatic setting.

As of April 18th 2022, the initial results from the study showed that Tenalisib was well tolerated across dose levels with majority of reported adverse events being mild-to-moderate in severity. Discontinuations and dose reductions due to related AEs were minimal (5-7.5%). The median duration of treatment thus far was ~4 months (0.93 to 6.23+ months) with ~60% of patients continuing on the study. The median time to response was 1.8 months and preliminary efficacy results indicate an encouraging 67.5% DCR which is maintained across patients with primary endocrine resistance as well. Correlation of responses observed with gene expression profiles by RNA sequencing from tumor biopsy samples post treatment with Tenalisib and analysis of cytokine/chemokine levels post Tenalisib treatment are underway.

“We are encouraged by the early activity seen with Tenalisib in the advanced/metastatic disease setting where patients have limited treatment options once they have failed CDK inhibitors and endocrine therapies. As these results continue to translate into durable responses, we will be engaging with key opinion leaders and regulatory agencies to discuss the monotherapy and combination development plans and registration-enabling study designs.” said Swaroop Vakkalanka, Founder & CEO of Rhizen Pharma. Swaroop also added that “Given the relevance of Tenalisib’s multi-valent mechanism across solid tumors, we expect these results will pave the way Tenalisib’s development to be expanded into other solid tumors. We are designing Tenalisib’s clinical programme carefully to arrive at an optimized dose and also deploy randomized study designs to fully elucidate its efficacy and safety.”

Rhizen indicated that Tenalisib, in addition to its selective dual PI3K δ/γ inhibitory activity, also has Salt-Inducible Kinase 3 (SIK3) activity via its principal metabolite, that could potentially contribute to its chemo-sensitization effect, 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.