A new small molecule DHODH-inhibitor [KIO-100 (PP-001)] targeting activated T cells for intraocular treatment of uveitis - A phase I clinical trial.

Uveitis is a T cell-mediated, intraocular inflammatory disease and one of the main causes of blindness in industrialized countries. There is a high unmet need for new immunomodulatory, steroid-sparing therapies, since only ciclosporin A and a single TNF-α-blocker are approved for non-infectious uveitis. A new small molecule inhibitor of dihydroorotate dehydrogenase (DHODH), an enzyme pivotal for de novo synthesis of pyrimidines, has a high potency for suppressing T and B cells and has already proven highly effective for treating uveitis in experimental rat models. Systemic and intraocular application of KIO-100 (PP-001) (previously called PP-001, now KIO-100) could efficiently suppress rat uveitis in a preventive as well as therapeutic mode. Here we describe the outcome of the first clinical phase 1 trial comparing three different doses of a single intraocular injection of KIO-100 (PP-001) in patients with non-infectious posterior segment uveitis. No toxic side effects on intraocular tissues or other adverse events were observed, while intraocular inflammation decreased, and visual acuity significantly improved. Macular edema, a sight-threatening complication in uveitis, showed regression 2 weeks after intraocular KIO-100 (PP-001) injection in some patients, indicating that this novel small molecule has a high potential as a new intraocular therapy for uveitis. Clinical trial registration: [https://www.clinicaltrials.gov/ct2/show/NCT03634475], identifier [NCT03634475].

Monolith affinity chromatography for the rapid quantification of a single-chain variable fragment immunotoxin.

We developed a novel analytical method for concentration determination of tandem single-chain antibody diphtheria toxin (immunotoxin). The method is based on polymethacrylate monoliths with Protein L ligands as the binding moiety. Different buffers were tested for elution of the Protein L-bound immunotoxin and 4.5 M guanidinium hydrochloride performed best. We optimized the elution conditions and the method sequence resulting in a fast and robust method with a runtime <10 min. Fast determination of immunotoxin is critical if any process decisions rely on this data. We determined method performance and a lower limit of detection of 27 µg/mL and a lower limit of quantification of 90 µg/mL was achieved. The validity of the method in terms of residual analysis, precision, and repeatability was proven in a range from 100 to 375 µg/mL. The short runtime and ease of use of a high-performance liquid chromatography method is especially useful for a process analytical tool approach. Bioprocesses related to immunotoxin where fermentation or other process parameters can be adjusted in accordance to the immunotoxin levels will be benefited from this method to achieve the highest possible purity and productivity.

Process development for the production of prebiotic galacto-oligosaccharides from lactose using beta-galactosidase from Lactobacillus sp.

Galacto-oligosaccharides (GOS) are formed from lactose in discontinuous mode of conversion using beta-galactosidase from Lactobacillus sp. (beta-gal). The discontinuous process was optimized for technical application with regard to GOS yield, enzyme preparation, reaction temperature and substrate source. It proved to be advantageous to directly apply the crude cell-free enzyme extract for the conversion, since similar GOS yields and composition were obtained as when using the pure enzyme preparation, but expensive purification could be avoided. Reaction temperature was lowered to 17 degrees C to limit microbial contamination when using technical substrates. Thereby GOS yield decreased from 30% to 28% of total sugars and enzyme demand increased 2.7-fold. Whey permeate was compared to buffered lactose solution as a substrate source. The initial reaction rate was found to be 1.8 times higher for the whey permeate substrate; however, GOS yield was slightly lower (approximately 25% of total sugar at 17 degrees C) mainly due to smaller amounts of allolactose[beta-D-Galp-(1-->6)-D-Glc] and the trisaccharide beta-D-Galp-(1-->6)-D-Lac formed.