The US Food and Drug Administration (FDA) has approved venetoclax for the treatment of chronic lymphocytic leukaemia (CLL).
The drug will be available to patients who have already received treatment with another therapy and who carry the 17p deletion, a chromosomal abnormality found in around 20% of relapsed patients. This mutation is associated with poor prognosis and patients are usually resistant to conventional therapies.
The approval decision was based on the results of a single-arm phase II trial involving 107 patients with relapsed or refractory CLL and the 17p deletion. They received the oral drug at escalating doses from 20mg to 400mg for five weeks (to reduce the risk of tumour lysis syndrome) before continuing at the 400mg dose until disease progression or discontinuation.
Overall, 79.4% achieved partial or complete remission of the disease and, one year later, 84.7% had retained their response to the drug.
Venetoclax, marketed as Venclexta by AbbVie, works by inhibiting BCL2, a protein that is overexpressed by CLL cells and renders them resistant to apoptosis.
The drug was approved via the FDA’s accelerated approval process, which allows expedited review of drugs for serious or life-threatening conditions. The European Medicines Agency has also accepted a submission from AbbVie for a marketing authorisation, which is currently under evaluation.