ZN-c3 demonstrated single agent activity, generating Exceptional Responses in a range of heavily pre-treated solid tumors
ZN-c3 was safe and well-tolerated
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NEW YORK and SAN DIEGO, April 10, 2021 (GLOBE NEWSWIRE) -- Zentalis Pharmaceuticals, Inc. (Nasdaq: ZNTL), a clinical-stage biopharmaceutical company focused on discovering and developing small molecule therapeutics targeting fundamental biological pathways of cancers, today announced initial efficacy and safety data from the Phase 1 dose-escalation portion of its ongoing Phase 1/2 clinical trial of ZN-c3 in patients with advanced solid tumors who are refractory to or ineligible for standard therapy or for whom no standard therapy is available. Initial results showed that monotherapy ZN-c3 use resulted in Exceptional Responses in heavily pre-treated patients in a range of solid tumors, including Partial Responses (PRs) in ovarian cancer, colorectal cancer, non-small cell lung carcinoma and uterine serous carcinoma. Data were reviewed as a late-breaking abstract during the American Association of Cancer Research (AACR) Annual Meeting, being held virtually April 10-15, 2021 and May 17-21, 2021.
“The initial clinical data on our WEE1 inhibitor are extremely promising and showcase ZN-c3’s strong potential to improve outcomes in patients with advanced solid tumors who have exhausted available treatment options,” commented Dr. Anthony Sun, Chairman and Chief Executive Officer of Zentalis. “Our WEE1 candidate, which we believe is potentially a best-in-class small molecule, demonstrated favorable safety results with a wide therapeutic window, and resulted in Partial Responses in five patients with a range of cancers. Having identified a recommended dose for future studies, we look forward to advancing clinical trials in a larger number of patients, as well as novel biomarkers that may help select patients who are likely to respond to treatment with ZN-c3. We are looking to make Exceptional Responses commonplace.”
Initial Efficacy and Safety Data
In the Phase 1 dose-escalation trial, ZN-c3 was dosed starting at 25 mg and going as high as 450 mg QD in patients with advanced or metastatic solid tumors. At the time of the data cutoff on February 12, 2021, 55 patients were evaluated for safety, the primary endpoint. The study remains ongoing and based on the data presented at AACR, ZN-c3 generated 5 Partial Responses.
Best Overall Responses:
- Two confirmed PRs in ovarian cancer and colorectal cancer (CRC) patients
- After receiving 18 prior lines of therapy, 11 prior lines in the advanced metastatic setting, a patient with Stage IV ovarian cancer had a RECIST-confirmed PR with a 56% reduction in overall target lesions. The patient also experienced a large rapid drop in CA-125 from 610 kU/L at baseline to 125 kU/L within 4 weeks on treatment, with her CA-125 level normalizing 3 weeks later. The patient was on study for 186 days and remains on study drug.
- After receiving 5 prior lines of therapy in the advanced metastatic setting, a patient with Stage IV CRC had a RECIST-confirmed PR with a 42% reduction in overall target lesions, as well as a rapid decrease in CEA tumor marker from 327 ng/mL at baseline to