The US Food and Drug Administration (FDA) has granted breakthrough therapy designation to the BCL-2 inhibitor venetoclax when given with rituximab to treat patients with relapsed or refractory chronic lymphocytic leukemia (CLL).
Venetoclax already had breakthrough designation from the FDA as single-agent treatment for patients with relapsed or refractory CLL and 17p deletion.
The drug was granted priority review for this indication as well.
Breakthrough therapy designation is designed to accelerate the development and review of medicines that demonstrate early clinical evidence of a substantial improvement over current treatment options for serious diseases.
The latest breakthrough designation for venetoclax is supported by a phase 2 study of the drug in combination with rituximab in patients with relapsed/refractory CLL. Results from this trial were presented at the 2015 ASH Annual Meeting (abstract 325).
Another phase 2 trial presented at that meeting (abstract LBA-6) showed that single-agent venetoclax is effective against CLL as well.
The drug has also proven active against other hematologic malignancies, including acute myeloid lekemia and multiple myeloma.
However, venetoclax has been shown to pose a risk of tumor lysis syndrome (TLS). In fact, TLS-related deaths temporarily halted enrollment in trials of venetoclax. But researchers discovered ways to reduce the risk of TLS, and the trials continued.
Venetoclax is being developed by AbbVie in partnership with Genentech and Roche.
