AbbVie, a global biopharmaceutical company, announced that a phase 2 trial of its investigational medicine venetoclax met its primary endpoint of achieving overall response rates in patients with relapsed/refractory or previously untreated chronic lymphocytic leukemia (CLL) with 17p deletion, according to an independent review analysis.

The open-label study evaluated the efficacy and safety of venetoclax, an inhibitor of the B-cell lymphoma-2 (BCL-2) protein that is being developed in partnership with Genentech and Roche. Venetoclax is an investigational oral BCL-2 inhibitor being evaluated for the treatment of patients with various cancer types. The BCL-2 protein prevents apoptosis of some cells, including lymphocytes, and can be expressed in some cancer types. Venetoclax is designed to selectively inhibit the function of the BCL-2 protein.


Data from this study will be presented at an upcoming medical conference and will serve as the pivotal registration data for applications to the FDA, EMA and other health authorities. The safety profile was similar to previous studies and no unexpected safety signals were reported for venetoclax.

"The results from this study demonstrate the clinical activity of venetoclax in patients with relapsed/refractory CLL who have 17p deletion, a patient population that has historically been difficult to treat," said Michael Severino, M.D., executive vice president of research and development and chief scientific officer, AbbVie.

"Based on these results, we intend to advance regulatory submissions for venetoclax and remain committed to the further development of this investigational medicine, and others in our pipeline, with the goal of delivering new treatment options for people affected by cancer."

In 2015, the FDA granted Breakthrough Therapy designation to venetoclax for the evaluation of treatment of CLL in previously treated (relapsed/refractory) patients with the 17p deletion genetic mutation.

CLL is a slow-progressing cancer of the bone marrow and blood in which the bone marrow makes too many lymphocytes, a type of white blood cell. It is the most common leukemia diagnosed in adults in western countries. In the United States, CLL accounts for approximately 14,620 new cases of leukemia diagnosed each year.

Approximately 3-10 per cent of CLL patients have 17p deletion at diagnosis, and it occurs in 30-50 per cent of patients with relapsed/refractory CLL. The 17p deletion mutation is a genomic alteration in which a part of chromosome 17 is absent. The median life expectancy for CLL patients with 17p deletion is less than 2-3 years.

The phase 2, multicenter, international, open label clinical trial was designed to evaluate the efficacy and safety of venetoclax in CLL patients with 17p deletion who relapsed, were refractory to existing therapies, or who were previously not treated for their CLL. The study has enrolled 157 patients, 107 in the main study cohort evaluating efficacy, and 50 patients in the safety expansion cohort.

The primary efficacy endpoint is overall response rate and the primary safety endpoints are the number and percentage of patients who experienced treatment-related adverse events, changes in physical exam findings, including vital signs, changes in clinical laboratory test results and changes in cardiac assessment findings. Secondary efficacy outcome measures include complete remission rate, partial remission rate, duration of response, overall survival and progression-free survival, among others.