The investment was led by HOPU Investments, YuanMing Capital, and participated in by other Chinese investors and existing U.S. investors Caxton Alternative Management L.P., ProQuest Investments, Venrock and CHL Medical Partners.

Concurrent with the investment, Mevion and the lead investors will form a joint venture in China to produce, sell and service proton therapy systems for the Chinese market. HOPU and YuanMing have extensive experience investing in successful healthcare companies and offer a significant network of healthcare experience in China.

With a cadre of international investors supporting its proton therapy leadership position, Mevion is poised to significantly expand its business globally and dramatically increase access to this important cancer therapy around the world. The investment will support an increase in Mevion’s manufacturing capacity and global service capability to support the installation of new proton therapy sites in the U.S., China and internationally.

"This investment is a clear endorsement of Mevion’s unique leading-edge proton therapy technology. No other system can match the quality, size, cost and efficiency of the MEVION S250, making it a powerful and practical solution for proton centers globally," said Joseph K. Jachinowski, President and CEO of Mevion Medical Systems.

"Proton therapy is an increasingly significant treatment modality for cancer centers around the world, and we see real value in advancing accessibility to this important therapy in China and elsewhere," said Sunny Li, Senior Managing Director and Head of Technology Investments of HOPU Investments.

The first Mevion system, which is installed at Barnes-Jewish Hospital in St. Louis, achieved the fastest per-room ramp-up of any proton therapy system in history, treating its first 100 patients in a single room in just 11 months. That system was followed by the clinical start of the Ackerman Cancer Center (ACC) in Jacksonville, Florida. The system at ACC beat all global patient treatment ramp-up records by reaching a per-room rate of 350 patients per year in less than three months.

This treatment rate is comparable to the total number of patients treated each year at costlier four-room legacy systems. And, this spring, Mevion became the first proton therapy manufacturer to open two facilities back-to-back; the system at Robert Wood Johnson University Hospital treated its first patient less than four weeks after the first patient was treated at ACC, further evidence of its breakthrough efficiency.

The MEVION S250 delivers higher-quality, targeted radiation therapy for cancer patients at a fraction of the size and operating costs and with much higher operational efficiency than the legacy proton systems.