Tioma Therapeutics Inc. hauled in $86 million in its series A to support development of a pipeline of anti-CD47 antibodies to treat solid and hematologic cancers. The stunning size of the round was designed to enable the company, founded a decade ago in St. Louis, Mo., as Vasculox Inc., to open a corporate office in Brisbane, Calif., and achieve an ambitious clinical program by advancing multiple candidates through proof of concept, both as monotherapy and in combination regimens.

"We have a pretty fat portfolio of anti-CD47 antibodies, and we wanted to put together a syndicate and a financing amount that would allow us to do the right scope of work, test these things in the clinic and determine if, how and to what extent CD47 inhibition benefits patients suffering from cancer," explained John Donovan, Tioma's president and CEO.

Proving that thesis will involve not only an initial safety study but also safety and efficacy studies in multiple settings.

"It's a robust scope of work," Donovan told BioWorld Today.

The round was co-led by seed investor Rivervest Venture Partners, including its 3×5 Rivervest Fund, along with Novo Ventures, Roche Venture Fund and Glaxosmithkline plc's venture arm, S.R. One. John McKearn, Rivervest managing director, was named chairman of Tioma's board, where he was joined by Novo's Peter Moldt, Carole Nuechterlein of Roche and S.R. One's Jill Carroll.

Scientific founder William Frazier, professor of biochemistry, molecular biophysics, cell biology and biomedical engineering at Washington University School of Medicine, formed Vasculox with Pamela Manning, the company's vice president of R&D, based on research from his laboratory and that of collaborators at the NIH. A pioneer in the field of CD47-mediated signaling pathways, Frazier discovered that CD47 is a receptor for thrombospondin-1, or THBS1, and advanced the company's research with seed rounds, grants "and the traditional shoestring approach," Donovan said.

Donovan credited McKearn with the vision for assembling the institutional round after Rivervest become a seed investor last year. In mid-2015, Vasculox closed on a financing of approximately $5 million that was intended to be first tranche of a larger syndicated round – expected, at the time, to be in the range of about $45 million, according to an SEC filing.

In February, the company recruited Donovan, who most recently was a co-founder of Alios Biopharma Inc., where he served as chief business officer and chief financial officer until its 2014 acquisition by Johnson & Johnson for $1.75 billion. (See BioWorld Today, Oct. 1, 2014.)

The expanded executive team – including Robert Karr, who joined the company in 2010 as chief scientific officer and had been serving as interim CEO – and investors sat down together to review the existing data, determine the company's strategy and assess the amount of work that would be needed to prove the science. Based on the existing data and the desire to execute a robust development plan, the company garnered support from its syndicate to increase the size of the planned A round.

"We decided to finance the whole thing through proof of concept," Donovan said. "We can now turn our attention to research and development and not get side-tracked every six or 12 months looking for additional capital."

Nothing 'preventing us from taking this all the way'

Although Alios was developing therapies to treat respiratory syncytial virus and hepatitis C virus, Donovan said his attraction to Tioma had the same appeal of his previous firm.

"I came up on the business side of this industry, so I always start with the people," he said, citing "a great group of investors" for bringing him to the table, where he was intrigued by the biology.

"I was convinced pretty quickly that the team assembled here knows as much about the CD47 biology as anyone in the world," Donovan maintained.

By targeting CD47, a protein expressed on most tumor cells, Tioma is pursuing a less-traveled approach in immuno-oncology – a field bent on waking the body's immune system to pursue and destroy cancer cells. But the integrin associated protein has appeal; in February, start-up Forty Seven Inc. landed a $75 million round to advance its humanized IgG4 kappa anti-CD47 monoclonal antibody through dual phase I studies. (See BioWorld Today, Feb. 25, 2016.)

Tioma is keeping details about its fully owned technology under wraps until it has more data in hand. The biology is complicated and unproven in the clinic, Donovan conceded, but the prospect that CD47 antibodies may be used to treat a broad number of oncology indications is equally compelling.

"There are multiple mechanisms of action at play here, mediated by the CD47 receptor," he said. "Therefore, CD47 inhibitors have the ability to exhibit a wide variety of functional characteristics. We think it's very intriguing biology, with a tremendous amount of potential."

The company's clinical plan is designed to investigate whether and to what extent CD47 inhibition improves coordination between the innate and adaptive immune systems to harness attacks against tumors and, if demonstrated successfully, in which patient populations.

"We're going to do robust clinical investigations that look at a variety of different cancers in a variety of different settings, including combination and monotherapy," Donovan said. "Our approach isn't just to put this into the clinic, put it in a few patients and then pinch your nose and hope for the best."

Tioma expects to advance its lead candidate to the clinic in the first half of 2017.

The company has fewer than 20 employees and Donovan expects to keep the head count in that vicinity for the next few years, selectively adding development officials at the Brisbane headquarters. The company plans to retain its scientists, research facilities and wet labs in St. Louis.

Long term, "there's nothing inherently preventing us from taking this all the way," Donovan said. "We don't want to partner right now. We feel like this is a great venture play. Our business case is to build a company with a viable stand-alone future."