The U.S. Food and Drug Administration today approved venetoclax for the treatment of patients with chronic lymphocytic leukaemia (CLL) who have a chromosomal abnormality called 17p deletion and who have been treated with at least one prior therapy.

Venetoclax is the first FDA-approved treatment that targets the B-cell lymphoma 2 (BCL-2) protein, which supports cancer cell growth and is overexpressed in many patients with CLL.

According to the National Cancer Institute, CLL is one of the most common types of leukaemia in adults, with approximately 15,000 new cases diagnosed each year.

CLL is characterised by the progressive accumulation of abnormal lymphocytes, a type of white blood cell.

Patients with CLL who have a 17p deletion lack a portion of the chromosome that acts to suppress cancer growth.

This chromosomal abnormality occurs in approximately 10 percent of patients with untreated CLL and in approximately 20 percent of patients with relapsed CLL.

“These patients now have a new, targeted therapy that inhibits a protein involved in keeping tumour cells alive,” said Richard Pazdur, director of the Office of Haematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research.

“For certain patients with CLL who have not had favourable outcomes with other therapies, venetoclax may provide a new option for their specific condition.”

The efficacy of venetoclax was tested in a single-arm clinical trial of 106 patients with CLL who have a 17p deletion and who had received at least one prior therapy.

Trial participants took venetoclax orally every day, beginning with 20 mg and increasing over a five-week period to 400 mg.

Results showed that 80 percent of trial participants experienced a complete or partial remission of their cancer.

Venetoclax is indicated for daily use after detection of 17p deletion is confirmed through the use of the FDA-approved companion diagnostic Vysis CLL FISH probe kit.

The most common side effects of venetoclax include low white blood cell count (neutropenia), diarrhoea, nausea, anaemia, upper respiratory tract infection, low platelet count (thrombocytopenia) and fatigue.

Serious complications can include pneumonia, neutropenia with fever, fever, autoimmune hemolytic anaemia, anaemia and metabolic abnormalities known as tumour lysis syndrome.

Live attenuated vaccines should not be given to patients taking venetoclax.

The FDA granted the venetoclax application breakthrough therapy designation, priority review status, and accelerated approval for this indication.

These are distinct programs intended to facilitate and expedite the development and review of certain new drugs in light of their potential to benefit patients with serious or life-threatening conditions.

Venetoclax also received orphan drug designation, which provides incentives such as tax credits, user fee waivers and eligibility for exclusivity to assist and encourage the development of drugs for rare diseases.

Source: FDA