This story originally ran on May 19 and has been updated to include additional information from an investor.
Caprotec Bioanalytics said last week that it had secured $5.1 million in a Series B financing round to continue development of its proprietary Capture Compound Mass Spectroscopy platform — a technology for isolating functionally selected proteins from complex biological samples that has potential uses in the study of drug-protein interactions and could increase the efficiency of the drug development process.
Investors in the round included Creathor Venture, IBB Beteiligungsgesellschaft, and ERP Startfonds.
According to Ute Mercker, senior investment manager at IBB Beteiligungsgesellschaft, the round marked a shift to greater emphasis on Caprotec's ImproMed division, which applies the CCMS technology in partnerships with drugmakers in order to predict drug-target interactions or off-target effects.
"There is a stronger focus on ImproMed," she told ProteoMonitor. "When we funded the company in the A round it was to commercialize the CCMS technology, and the focus was on the [caproKits]. [This round] is for both divisions, you could say. We have kits on the market we want to distribute and develop more of, and we want to make more collaborations with pharmaceutical companies in the drug development process."
Key to IBB's increased focus on ImproMed, Mercker said, was a study published this year in the January 2010 issue of Toxicological Sciences in which a team of researchers including Caprotec CEO Hubert Koster demonstrated the potential usefulness of CCMS technology in the development of drugs for Parkinson's disease.
The researchers used CCMS to examine the molecular basis for side effects caused by the Parkinson's disease drugs tolcapone and entacapone. Using tri-functional synthetic molecules called capture compound molecules with the drugs themselves as the reactivity function, the researchers successfully isolated and identified the drugs' known target, cathechol-O-methyltransferase. They also identified off-target protein interactions, particularly in the case of tolcapone, which was shown to interact with components of the respiratory chain and of fatty acid beta-oxidation. This observation fit with previous studies involving tolcapone-treated rats that suggested tolcapone might act as a decoupling reagent of the respiratory chain.
"We saw that this technology really had the potential to improve the drug development process in the very early stages when you can try to optimize compounds with regards to potential side effects," Mercker said.
Presently, Caprotec is planning a study using CCMS to identify the cause of liver toxicity in a withdrawn oral thrombin inhibitor with the goal of designing a new drug without liver toxicity.
Caprotec's CCMS technology is based on capture compounds that isolate functionally selected proteins on the basis of small molecule-protein interactions. The CCs' selectivity function allows the molecules to bind reversibly with the targeted protein. The molecules' reactivity function then — upon photo-activation — forms a covalent bond with the targeted protein. Then the captured proteins are pulled out and isolated via streptavidin magnetic beads that bind to the CCs' biotin sorting function and analyzed via mass spectrometry.
The company claims that the technology offers certain advantages over traditional approaches like affinity beads. The covalent bond formed by the molecules' reactivity function allows for stringent washing, which provides for the isolation of weakly bound proteins. This is particularly useful for drug development in that it enables researchers to identify off-target proteins that may contribute to side effects.
CCMS is also able to isolate proteins present in small quantities, making it a useful technology for dealing with limited proteome samples like tissue biopsies, the company said.
Caprotec launched in late 2007 after receiving $6.6 million in venture capital from investors including ERP Startfronds and IBB — both of which also participated in the recent Series B round. It received an additional $2.3 million in venture funding at the beginning of 2008 from investors including Creathor Venture, also a participant in the recent Series B round. In May of 2008, the company entered into an agreement with Merck to use CCMS technology to identify relevant protein-drug molecule interactions.
According to Mercker, Caprotec has since partnered with several other companies on drug development, including additional big pharmaceutical firms, although she declined to give any specific names.
The company also plans to expand its portfolio of caproKits — CCMS-based tools that allow researchers to identify and isolate functionally selected protein classes for study. The company offers kits for seven protein classes — the cAMP, cGMP, GDP, Stauro, SAH, SAHA, and Marimastat caproKits — and is developing three new kits designed for the study of epigenetics, signal transduction, and hormones.
As Koster told ProteoMonitor upon launching Caprotec in 2007, caproKits and the CC molecule technology in general increase the usefulness of mass spectrometry by offering researchers a way to select a narrower field of proteins to look at before beginning mass spec analysis (PM 12/06/2007).
"The key... is reducing the complexity of the proteome, and then you can use mass spectrometry," he said. "Otherwise, you are swimming in a sea of information."
Citing additional investor interest, Mercker said that a second closing of Series B funding could be completed some time this year.
"We don't need it. Right now the company is financed. But there is interest in the market, so we might consider a second closing if we think we can build something valuable out of the CCMS technology," she said.
Caprotec officials could not be reached for further comment for this article.