Developed using the company’s PEGylation technology, PEG-SN38, a PEGylated conjugate of SN38 will provide therapeutic advantages over unmodified SN38 and current therapies.
The Phase II study will investigate the efficacy of single-agent PEG-SN38 in 164 female patients who had previously been treated for metastatic breast cancer with either anthracycline and taxane (AT) or anthracycline, taxane and capecitabine (ATX).
In the AT and ATX cohorts, the median duration response was 4.2 and 5.2 months, median progression-free survival rate was 3.8 and 3.4 months, and overall survival rate was 10.5 and 8 months, respectively.
PEG-SN38 was also found to be safe and well tolerated in the pretreated patients, with neutropenia, diarrhea and leukopenia.
Enzon Pharmaceuticals vice-president Aby Buchbinder said the results of the study confirm the earlier findings demonstrating PEG-SN38’s anti-tumor activity in breast cancer.
”Furthermore, they contribute to the substantial clinical evidence indicating the potential of PEG-SN38 to deliver meaningful therapeutic benefit in multiple oncology indications in which the full benefit of irinotecan cannot be realised due to toxicity," Buchbinder added.