Zentalis Pharmaceuticals Announces Promising Initial Data Presented in a Late-Breaking Session at AACR on ZN-c3, its WEE1 Inhibitor, in Patients with Advanced Solid Tumors - Seite 2

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 <50 ng/mL after 3 weeks on treatment. The patient remained on study for 169 days until clinical disease progression.
• In addition, three unconfirmed PRs—one in non-small cell lung carcinoma (NSCLC) and two in uterine serous carcinoma (USC) patients
  • After receiving 3 prior lines of therapy in the advanced metastatic setting, a patient with Stage IV NSCLC had an unconfirmed (per RECIST) PR with a 50% reduction in overall target lesions. The patient was on study for 145 days and remains on study drug.
    

ZN-c3 was generally well-tolerated as a single agent. As of the cutoff date, the most common treatment-related adverse events were mainly Grade 1/2, including nausea (49.0% of patients), diarrhea (32.7% of patients), fatigue (29.0% of patients) and vomiting (29.0% of patients) across all doses. Significant hematological adverse events were limited; treatment-related white blood cell count decrease / neutropenia (7.2% all Grades, 3.6% Grade ≥3), anemia (7.2% all Grades, 5.4% Grade ≥3) and thrombocytopenia (7.2% all Grades, 3.6% Grade ≥3).