2X-121 is a small molecule targeted inhibitor of Poly ADP ribose polymerase (PARP), a key enzyme involved in DNA damage repair in cancer cells. The PARP inhibitor demonstrated clinical activity in a prior Phase 1 study in a number of cancers, including ovarian and breast. The drug also has potential to treat brain metastases and primary brain tumors based on its ability to pass through the blood-brain barrier.
About 2X-121
2X-121 has a novel dual-inhibitory action against both PARP 1/2 and Tankyrase 1/2. The molecule is also active in P-glycoprotein expressing cells, suggesting it may overcome PARP inhibitor resistance.
A Phase 2 study (>20 patients) is planned using a DRP biomarker in metastatic breast cancer patients to identify patients likely to respond to and benefit from treatment with 2X-121. Positive data from this study will position the program for a pivotal Phase 2 study initiation in 2018.
In a prior Phase 1 study conducted without a DRP, two patients had a durable partial response (281 and 208 days, respectively). 2X-121 was well tolerated with no myelotoxicity observed. The planned Phase 2 study using a DRP is expected to significantly improve response rates seen in this initial study.