Patients with difficult to treat forms of chronic lymphocytic leukaemia (CLL) have gained a new treatment option after the European Commission issued a green light for AbbVie's Venclyxto.

Specifically the drug is indicated as a monotherapy for the treatment of CLL in adult patients in the absence of 17p deletion or TP53 mutation who have failed both chemo‑immunotherapy and a B-cell receptor (BCR) inhibitor.

Venclyxto (venetoclax) can also be used as monotherapy for the treatment of adult CLL patients with these mutations who are either unsuitable for or have failed a BCR inhibitor.

One in two CLL patients failing current standards of care could face survival as short as three months. According to AbbVie, in those failing on B-cell receptor (BCR) inhibitors, 72 percent of patients taking Venclyxto are yet to have their disease progress after 12 months. In patients with previously treated CLL and 17p deletion, median progression free survival is over 27 months, the firm noted.

Venclyxto works by targeting the B‐cell lymphoma‐2 protein, which regulates cell survival, restoring the body's ability to trigger cancer cell self-destruction (apoptosis). 

The drug was approved in the US in April, on the back of efficacy data from a single-arm clinical trial of 106 pre-treated CLL patients with 17p deletion, which showed that 80 percent taking the drug experienced a complete or partial remission of their cancer.

It has also been available to patients in the UK through the country's Early Access to Medicines Scheme, which allows use of promising treatments before they are licensed by the regulator where there is unmet need.

The drug's approval "may begin to address a critical unmet need in a difficult-to-treat patient population who have used all available treatment options," noted Nick York, from the CLL Support Association.

"At the moment, there is a treatment void for those with hard to treat CLL who are not suitable for treatment with BCR inhibitors or who have relapsed from them. The evidence we have seen so far for venetoclax suggests it can help to extend lives and can potentially play a role in enabling patients, their carers and families to more fully live their lives."

CLL is the most common form of leukaemia in adults, affecting the lives of nearly 3,500 people in the UK each year.