Prof. Christian W. Gruber

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About

Christian Gruber leads the Drug Discovery and Peptidomics group at the Medical University of Vienna (MedUni Wien), one of Europe's largest and most prestigious medical research institutions. His research spans two interconnected frontiers: the global biodiversity of cyclotides — systematically mapping which plants produce which cyclotide variants and why — and the translation of that knowledge into drugs for immunological and neurological diseases.

Gruber was named Inventor of the Year 2015 at MedUni Vienna in recognition of his development of T20K, a modified form of kalata B1 that has become the first cyclotide molecule to enter human clinical trials. Licensed to the Swedish biopharmaceutical company Cyxone AB, T20K is being investigated as a treatment for multiple sclerosis — one of the most significant milestones in the history of cyclotide science.

Background & Career

Gruber's training bridges pharmacology, natural product chemistry, and molecular biology — an interdisciplinary foundation that has proved essential for cyclotide research, which sits at the intersection of all three. At MedUni Vienna he built the Drug Discovery and Peptidomics group into one of Europe's leading cyclotide research centres, with particular strengths in mass spectrometry-based cyclotide profiling and GPCR pharmacology.

His collaborations extend to researchers across Europe, Australia, and South America, and he has been a key figure in building the global cyclotide research community through co-authored reviews, collaborative expeditions, and the organisation of the field's scientific meetings.

Key Contributions

• Global Cyclotide Adventure: Led the most comprehensive systematic survey of cyclotide distribution across the plant kingdom — covering 340+ flowering plant species across Tanzania, Brazil, Venezuela, Hawaii, and Europe. This work dramatically expanded knowledge of which plant families produce cyclotides and what structural variants exist in nature.
• T20K — first cyclotide in human clinical trials: Engineered [T20K]kalata B1, a modified kalata B1 variant with a threonine-to-lysine substitution at position 20 that eliminates haemolytic activity while retaining strong immunomodulatory properties. T20K has been licensed to Cyxone AB and entered Phase I/II clinical trials for relapsing-remitting multiple sclerosis — the first time a cyclotide has been tested in humans.
• Cyclotides in Fabaceae: Co-discovered cyclotide-like sequences in the Fabaceae (legume) plant family, significantly expanding the known evolutionary and taxonomic distribution of the cyclotide scaffold beyond the Rubiaceae and Violaceae families where they were first identified.
• GPCR-targeted cyclotide design: Pioneered a systematic approach to engineering cyclotide scaffolds as ligands for G-protein coupled receptors (GPCRs) — the target class of approximately one-third of all approved drugs. This work opens a broad avenue for cyclotide-based drug development in neurology, immunology, and metabolic disease.
• Cyclotide peptidomics: Advanced the use of mass spectrometry for high-throughput discovery and profiling of cyclotide diversity — enabling rapid screening of plant extracts and the identification of novel cyclotide variants without the need for lengthy isolation procedures.

T20K in Clinical Trials

The progression of T20K into human clinical testing represents a landmark moment for the entire cyclotide field. Multiple sclerosis is a chronic autoimmune disease in which the immune system attacks the myelin sheaths of nerve cells; existing disease-modifying therapies carry significant side effects or require injection. T20K's immunomodulatory activity — suppressing the T-cell responses implicated in MS — combined with its oral bioavailability make it a potentially transformative therapeutic candidate.

Key Publications