The rise and rise of Keytruda (pembrolizumab) continues with two more approvals in Japan, taking its total in that country to 15 indications across nine tumour types.
The Japan Pharmaceuticals and Medical Devices Agency (PMDA) has approved the use of Merck/MSD’s Keytruda in patients with inoperable or recurrent breast cancer that is PD-L1 positive, hormone receptor negative and human epidermal growth factor receptor 2 (HER2) negative.
This approval is particularly important for the country as so-called ‘triple-negative’ breast cancer (TNBC) is more prevalent in Japan than in the US, with around 15% of patients with breast cancer in Japan diagnosed with TNBC. Breast cancer is the most commonly diagnosed cancer in women in Japan, with more than 94,000 people diagnosed in 2020.
The second indication is in colorectal cancer, targeting unresectable, advanced or recurrent high microsatellite instability (MSI-H) colorectal cancer. Colorectal cancer is the most commonly diagnosed cancer in Japan, with an estimated 157,000 cases of colorectal cancer a year.
“These approvals further demonstrate that Keytruda and Keytruda-based combinations have the potential to help certain patients in Japan who are facing cancers,” said Kyle Tattle, president of MSD Japan. “The prevalence of breast and colorectal cancer is particularly high in Japan, and we are committed to working with the government so that patients have access to these immunotherapy treatment options.”
Keytruda, an anti-programmed death receptor-1 (PD-1) therapy, increased the ability of the immune system to detect and fight tumour cells. It is a humanised monoclonal antibody that blocks the interaction between PD-1 and its ligands, PD-L1 and PD-L2, thereby activating T lymphocytes which may affect both tumour cells and healthy cells.
For a drug that was once considered so unpromising that it was placed on a list for out-licensing, Keytruda’s ongoing success is unparalleled. This year alone, the drug has already earned Merck more than $8bn in sales, and it looks likely its revenues will far surpass last year’s total of $14.4bn.
Competition is hot in the PD1/PD-L1 inhibitor market, as Merck’s Keytruda fights with Bristol Myers Squibb’s Opdivo (nivolumab), Roche’s Tecentriq (atezolizumab), AstraZeneca’s Imfinzi (durvalumab) and many more approved and experimental treatments. However, with the currently $32bn market expected to reach $120bn a year by the end of 2027, the spoils for the winners are considerable.
Merck is betting big on immuno-oncology, with the industry’s largest clinical research programme that involves more than 1,500 trials studying Keytruda across a wide variety of cancers and treatment settings.
Keytruda is approved in a huge range of oncology indications across the world. In the US alone, it is indicated for cancers including melanoma, non-small cell lung cancer, carcinomas, classical Hodgkin lymphoma, gastric and oesophageal, cervical and triple-negative breast cancer.