Mevion Medical Systems, the leading provider of advanced proton therapy systems, announced today that it has entered into an investment agreement where up to $200 million will be invested in Mevion to accelerate its worldwide expansion. 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. 'Mevion has more modular proton therapy systems ordered, installed and treating than all other manufacturers combined. And, the compelling clinical and business results from our operational systems, and the momentum we are building, is powerful evidence that the future is bright, both for Mevion and for the cancer patients who will benefit from having wider access to proton therapy.'

'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. 'We have conducted an extensive industry survey of proton therapy companies. Only one company is commercially proven to have both the best technology and the best economics for healthcare providers and that is Mevion. We wanted to be a part of this success story.'

Yuan Tian and Dr. Tina Yu, Partners of YuanMing Capital, stated, 'We are very interested in investing in medtech leaders in the U.S. like Mevion, and truly believe that we can help these U.S. companies grow and maximize value in the Chinese market.'

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. Its modular design and smaller footprint - a single-room format occupies only 2,000 sq. ft. (180 sq. m) - means that a MEVION S250 can be added to existing cancer facilities in even the most densely populated cities with extreme space constraints while installations can be scaled to provide multi-room capabilities at large cancer hospitals. And, it is the most environmentally friendly system using less than ten percent of the energy of legacy systems. Overall the Mevion system offers customers the best economics for building and running a proton facility in the current challenging reimbursement environment. The versatility of MEVION S250 will greatly increase accessibility for patients across the globe.

About Mevion Medical Systems

Mevion Medical Systems, Inc. is a leading provider of proton therapy systems for use in radiation treatment for cancer patients. Mevion's flagship product, the MEVION S250 proton therapy platform, is the only modular, single room proton therapy system currently on the market. The MEVION S250 integrates with standard radiation therapy workflow and provides a proton therapy treatment environment at a fraction of the cost, footprint and operational complexity of conventional systems.

Mevion is privately held and based in Littleton, Massachusetts, with international offices in the United Kingdom and Japan. For more information, please visit www.mevion.com.

About HOPU Investments

HOPU Investments is a private equity firm focusing on China-related investment opportunities. With offices located in Beijing, Hong Kong, and Singapore, HOPU's team has unique expertise in investment, financing, and capital markets, as well as diverse experience working with state-owned enterprises and private entrepreneurs. HOPU's key investment focus is to create, develop, and pursue investment opportunities driven by China's ongoing economic reforms and development, particularly in the healthcare, technology, consumer, energy, mining, agriculture, and financial services sectors.

About YuanMing Capital

YuanMing Capital is a healthcare specialty fund focusing on China-US cross border investments with offices in Beijing and New York City. The investment team has rich industry experience and a successful investment track record. The fund invests in therapeutics, medical devices, diagnostics as well as healthcare service companies based in US and/or China. It brings capital and strategic resources to the future leaders of the industry. www.yuanmingcapital.com