Incyclix Bio has announced interim results from the dose escalation portion of its Phase I/II INX-315-01 trial, evaluating INX-315 as a treatment for advanced breast cancer and other solid tumors. The open-label, first-in-human study assessed the safety, tolerability, pharmacokinetics, and preliminary anti-tumor activity of INX-315 in patients with recurrent advanced/metastatic cancers.
The trial focused on patients with estrogen receptor-positive/human epidermal growth factor receptor 2-negative (ER+/HER2-) breast cancer resistant to cyclin-dependent kinase 4/6 (CDK4/6) inhibitors, as well as those with CCNE1-amplified solid tumors. These cancers often present significant treatment challenges due to resistance to existing therapies.
Safety and Tolerability
The interim data indicated that INX-315 was well-tolerated as a single agent among the 31 subjects enrolled. Notably, only one instance of dose-limiting toxicity was observed, and no patients discontinued treatment due to adverse events. This favorable safety profile is crucial for a heavily pretreated patient population.
Anti-tumor Activity
The anti-tumor activity of INX-315 was particularly encouraging. Among subjects evaluated for response, 10% achieved a partial response (PR), and 63% maintained stable disease (SD). In the subgroup of patients with ER+/HER2- breast cancer, 10% experienced PR and 50% had SD. Furthermore, in subjects with CCNE1-amplified high-grade serous ovarian cancer (HGSOC)/fallopian, 20% achieved PR and 80% had SD.
Patient Demographics and Treatment History
The median age of the participants was 60 years (range: 29-78), with 74% being female. The tumors studied included ER+/HER2- breast cancer, HGSOC, and other solid tumors. Subjects had undergone a median of four prior lines of therapy, highlighting the advanced and treatment-resistant nature of their cancers.
Implications and Future Directions
The data suggest that INX-315 has the potential to be used as a single agent in treating CCNE1-amplified solid tumors and in combination with standard care therapies for ER+/HER2- breast cancer. The ongoing monotherapy and combination dose-expansion phases of the trial will further evaluate these possibilities.
According to Incyclix Bio CEO and co-founder Patrick Roberts, the data underscores the safety, tolerability, and encouraging anti-tumor activity of INX-315 in heavily pretreated patients with advanced, treatment-resistant breast and ovarian cancers. He added that sharing these results with leading oncologists at SABCS is a significant milestone, reinforcing the potential of INX-315 to deliver a transformative treatment option for patients facing some of the most challenging cancer diagnoses.
