Officials with the FDA have granted Breakthrough Therapy designation for pembrolizumab (Keytruda, Merck) in combination with lenvatinib (Lenvima, Eisai) for the first-line treatment of advanced unresectable hepatocellular carcinoma (HCC) not amenable to locoregional treatment, according to a press release. 
 
The breakthrough designation is based on interim results from the phase 1b clinical trial KEYNOTE-524/Study 116, which evaluated the safety and efficacy of the combination treatment in patients with unresectable HCC. 
 
In 2019, it is estimated there will be more than 42,000 new liver cancer cases diagnosed in the United States, according to Merck. HCC is the most common type of liver cancer, accounting for approximately 90% of these cases. Patients with unresectable disease have a worse prognosis, with a median survival of less than 1 year. 
 
For the study, patients received pembrolizumab 200 mg intravenously every 3 weeks plus lenvatinib 12 mg per day for those weighing 60 kg or more and 8 mg per day for those weighing less than 60 kg. Safety and tolerability were the primary endpoints. Following tolerability confirmation in the first part of the trial, additional patients with no prior systemic therapy for unresectable HCC were enrolled in the expansion part of the trial. This part of the study is evaluating objective response rate and duration of response. 
 
“As part of our ongoing collaboration with Eisai, we are committed to evaluating the potential of Keytruda plus Lenvima across a number of different types of cancer,” Jonathan Cheng, MD, vice president of oncology clinical research at Merck Research Laboratories, said in a statement. “With this Breakthrough Therapy designation from the FDA, we look forward to working with Eisai to potentially build upon our existing indications for this difficult-to-treat cancer, so that we can help patients through a combination approach.”
 
This is the third Breakthrough Therapy designation granted to pembrolizumab in combination with lenvatinib. The first 2 designations were in advanced and/or metastatic renal cell carcinoma and advanced and/or metastatic non-microsatellite renal cell carcinoma and advanced and/or metastatic non-microsatellite instability-high/proficient mismatch repair endometrial carcinoma. 
 
Pembrolizumab plus lenvatinib is not currently approved for any cancer indications. 
 
Reference
 
Merck and Eisai Receive Third Breakthrough Therapy Designation from FDA for Keytruda (pembrolizumab) plus Lenvima (lenvatinib) Combination Treatment [news release]. Merck. https://www.mrknewsroom.com/news-release/oncology/merck-and-eisai-receive-third-breakthrough-therapy-designation-fda-keytruda-pe. Accessed July 23, 2019.