Sutro Biopharma - 2014 Fierce 15

Sutro Biopharma
Sutro attracts a marquee group of backers to its next-gen ADCs and bispecifics

CEO: William Newell
Based: South San Francisco, CA
Founded: 2004
Clinical focus: Antibody-drug conjugates and bispecifics
Website: www.sutrobio.com

The scoop: Simply put, Sutro's team believes it has devised a much better way to build antibody-drug conjugates--those precise cancer cell-killing constructs made up of a targeting antibody, linker and payload--and bispecifics, teeing up potentially best-in-class products that promise to be more efficiently and consistently manufactured. Using biochemical synthesis, they've hatched a technology that can bypass the current approach to biologics by genetically engineering drugs that are much simpler to make, more akin to small molecules. Their technology, which can be deployed with multiple warheads, has attracted the likes of Celgene ($CELG) (a prolific partnering machine), J&J ($JNJ) and Sanofi ($SNY). Just days ago Merck KGaA signed on after impressing the Sutro team with its work on tumor biology.

What makes Sutro Fierce: Sutro was spun out of Stanford, an intellectual hotbed of basic drug research that has helped make the region a global hub that has been drawing in billions of dollars of investment cash in recent years. It's following a classic biotech business model, building up its scientific foundation, adding in marquee partners from the Big Pharma world and getting a mix of A-list VCs and industry leaders to fund their work to the tune of more than $90 million.

Back at the end of 2012, when Celgene stepped in, CEO William Newell described the work this way: The first generation of ADCs was made up of what he called structurally heterogeneous populations--or mixtures--in which the position and number of conjugated linkers and warheads varied quite a lot. That kind of heterogeneity prevented the clear definition of important structure-activity relationships (SARs).

"Consequently," he went on, "using traditional ADC technologies prevents researchers from discovering and developing single-species candidates with optimal therapeutic indices and can result in products with unpredictable and suboptimal pharmacokinetic properties, stability and efficacy."

"Sutro," he added, "can incorporate non-natural amino acids (nnAA) at any site in an antibody structure, thereby allowing for single-species ADCs with site-specific conjugation of linker and warhead. Of vital importance in this process is Sutro's ability to perform rapid analyses early in discovery to define SARs and locate the best positions for nnAA incorporation." And because the company can rapidly gin up a quantity of proteins for early tox tests and clinical studies, developers can compress their development time.

At the time, Newell--relying on a scientific team led by Trevor Hallam, a Big Pharma alumnus with a stint at AstraZeneca ($AZN)--was promising one or two new pacts a year. Sutro delivered as promised, and then some. And they're working with some of the best people in the business.

At the beginning of this year, Memorial Sloan-Kettering Cancer Center turned to Sutro and its cell-free protein synthesis technology to make bispecifics its scientists had discovered for neuroblastoma in children. And few groups of scientists understand this work better than the group at MSKCC.

The promise of this kind of technology is hugely important, though there is the not-so-small task of providing the kind of data that proves that they're right. The trick to this business is betting the right way early enough to be on the cutting edge of the second wave. And that's just where Sutro is positioned right now.

Investors: Alta Partners, Amgen Ventures, Celgene, Lilly Ventures, Skyline Ventures and SV Life Sciences

For more: 
Sutro adds Merck KGaA to its roster of marquee 'armed antibody' partners
Big Biopharmas help fuel a $26M round for Sutro's immunotherapy work
Sanofi Pasteur, Sutro team up on vaccine candidates

-- John Carroll (email | Twitter)

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Sutro Biopharma - 2014 Fierce 15