Cantrixil, an investigative therapy which targets cancer cells that cause recurrence, shows promise as a treatment for ovarian cancer patients who failed at least two prior therapies, according to Australia-based Kazia Therapeutics (formerly Novogen).
The treatment is being assessed alone and in combination with chemotherapy. To date, 60% of patients (three out of five) who received the first two cycles of Cantrixil have seen their disease stabilize, and one patient who received the combination achieved a partial response.
Women with late-stage ovarian cancer who fail to benefit from existing chemotherapies have poor outcomes. Cantrixil is anticipated to provide a new treatment option for these women.
The therapy candidate is composed of benzopyran, a molecule that targets all cancer cells, including those that cause cancer recurrence and metastasis, called tumor-initiating cells. This is thought to restore patients’ sensitivity to chemotherapy.
Besides investigating whether Cantrixil is safe, the trial (NCT02903771) will also determine the drug’s maximum tolerated dose. Researchers are administering it once a week through the peritoneum, or abdominal cavity.
The study is being conducted in the United States and Australia, and is threefold.
In part A, patients will receive ascending doses of Cantrixil alone to determine the treatment’s maximum tolerated dose. After receiving Cantrixil for two cycles (with three weeks each), patients who tolerate the treatment may continue to receive it along with chemotherapy for an additional six cycles.
Once the maximum tolerated dose is established, researchers will initiate an expansion part — part B — testing the efficacy of this dose. A similar dosing regimen will be used: two cycles of Cantrixil alone, followed by six cycles in combination with chemotherapy.
Part C will then test the feasibility of Cantrixil given twice-weekly.
To date, 10 patients have been included in part A. Two patients were removed from the study before receiving Cantrixil due to disease worsening.
Among the five patients evaluable for efficacy, three patients achieved a stable disease after the first two cycles with Cantrixil alone, and one patient had a partial tumor reduction after receiving Cantrixil and chemotherapy.
A total of three patients completed the eight cycles of Cantrixil allowed.
The Data Monitoring Committee advised that additional patients be enrolled to assess the full spectrum of safety and determine the maximum tolerated dose with confidence. Kazia expects to complete part A by year’s end, which will be followed by part B.
“We are pleased with the progress of the study to date. Our understanding of both the safety and potential efficacy of Cantrixil will evolve as the study progresses further, and we look forward to sharing additional data as it is determined,” James Garner, CEO of Kazia Therapeutics, said in a press release.