The U.S. Food and Drug Administration (FDA) has granted Breakthrough Therapy Designation for atezolizumab in combination with bevacizumab as an initial (first-line) treatment for people with advanced or metastatic hepatocellular carcinoma (HCC), the most common form of liver cancer.

HCC accounts for approximately 75 percent of all liver cancer cases diagnosed in the United States, with more than 20,000 men and more than 5,000 women diagnosed annually.

HCC develops predominantly in people with cirrhosis due to chronic hepatitis B or C, and typically presents at an advanced stage where there are limited treatment options

The designation is based on data from a Phase Ib study assessing the safety and clinical activity of the combination.

Data was presented at the American Society of Clinical Oncology (ASCO) Annual Meeting in June 2018, and has led to a phase III trial (IMbrave150), now ongoing.

These data showed that after a median follow-up of 10.3 months, responses (independent review facility [IRF] per RECIST v1.1) were seen in 15 (65 percent) of 23 efficacy-evaluable participants.

Responses were seen in all subgroups, including on the basis of the cause of their disease (aetiology: Hepatitis B, Hepatitis C and non-viral), region (Asia [excluding Japan] or Japan/U.S.), baseline alpha-fetoprotein levels (high/low) or spread of tumor beyond the liver (yes/no).

Assessment by investigators (INV) assessed per RECIST v1.1 demonstrated a response rate of 61 percent (14 out of 23 participants).

Median progression-free survival (PFS), duration of response (DoR), time to progression (TTP) and overall survival (OS) have not yet been reached after a median follow-up of 10.3 months; results will be presented at a future medical congress when updated data from an expanded cohort are available.

In the safety-evaluable population (n=43), 28 percent of participants (n=12) experienced Grade 3-4 treatment-related adverse events (AEs), and no treatment-related Grade 5 AEs were observed.

No new safety signals were identified beyond the established safety profiles for the individual medicines.

Source: Genentech