Leo Cancer Care Raises $65M in Series D Funding Round

The round also saw participation from Eventide Asset Management, alongside continued support from its existing investors.

The company will use the funding to expand its operations and continue developing its products.

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The funding will help Leo Cancer Care increase manufacturing, speed up commercial deployment, and continue the clinical and product development of its upright cancer care platform. The platform supports proton therapy, photon therapy, and imaging, using the same upright design from diagnosis and treatment planning through to therapy.

Leo's approach is based on the idea that people naturally spend most of their lives standing or sitting upright. Research suggests this position may provide more consistent body and organ alignment than traditional lying-down treatments. The platform includes an FDA-cleared upright imaging system that supports treatment planning today and may also be used in future radiology applications.

Leo Cancer Care reached a major milestone on June 4, 2026, when Stanford Medicine delivered the worlds first compact upright proton therapy treatment using the company's Marie® platform. The first patient was a seven year old child receiving treatment for a complex brain tumor.

Instead of rotating a large, heavy gantry, the Marie® system keeps the radiation beam fixed while gently rotating the seated patient. This design reduces the size of a proton therapy treatment room by about five times compared with traditional systems, making it possible to install proton therapy in existing radiotherapy facilities and expand access to advanced cancer treatment.

“What began as a vision to improve radiation therapy has evolved into something much broader,” said Stephen Towe, CEO and Co-Founder of Leo Cancer Care. “For decades, the industry has tried to lower the cost of cancer care by making equipment cheaper and stripping out capability. Our treatment approach is the opposite — to reimagine how care is delivered, designed around the patient rather than the machine, so advanced treatment can reach communities that never had access before, without compromising quality.

“Leo Cancer Care is poised to revolutionize cancer treatment in more than ten countries, with many installations the first in their region or country,” said PR Yu, founder of Yu Galaxy and a long-time investor in the company. “The upright radiotherapy and radiology technologies Leo has pioneered are lowering the cost and shortening the time of cancer treatment, and providing options that did not exist before for pediatric patients and patients of larger body size.

About Leo Cancer Care

Founded in 2014 by Stephen Towe, Leo Cancer Care develops radiation therapy technology designed to make cancer treatment more efficient and comfortable for patients. Its Marie® system positions patients upright and uses CT imaging with a fixed radiation beam, gently rotating the patient during treatment instead of moving large equipment.

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