Discovery Programs

tRNA Synthetase Biology

Extracellular tRNA synthetase biology represents a novel set of potential physiological modulators and therapeutic targets.

Using ATYR1923 as a model, we have developed a process to advance novel tRNA synthetase domains from concept to clinical product candidate. This process leverages our early discovery work as well as current scientific understanding of tRNA synthetase protein structure, gene splicing and tissue-specific regulation to identify potentially active protein domains. Screening approaches are employed to identify target cells and extracellular receptors for these tRNA synthetase-derived proteins. These cellular systems can be used in mechanism-of-action studies to elucidate the role these proteins play in cellular responses and their potential therapeutic utility. We are working to identify new tRNA synthetase based drug candidates through our internal discovery efforts as well as industry and academic collaborations.

CSL Behring Collaboration

In March 2019, we entered into a research collaboration and option agreement with CSL Behring for the development of product candidates derived from up to four tRNA synthetases from our preclinical pipeline. Under the terms of the collaboration, CSL Behring will fund all research and development activities related to the development of the applicable product candidates for the duration of the collaboration. CSL Behring will pay a total of up to $4.25 million per synthetase program ($17 million if all four synthetase programs advance) in option fees based on the achievement of research milestones and CSL Behring’s determination to continue development. In addition, aTyr has granted CSL Behring an option to negotiate licenses for worldwide rights to each IND candidate that emerges from this research collaboration. Specific license terms will be negotiated during an exclusivity period following the exercise of each program option.

NRP2 Biology

aTyr is actively working on NRP2 receptor biology pathways of interest to select additional product candidates for preclinical and clinical investigation in a variety of disease settings through efforts internally, as well as with collaborators in academia.

NRP2 is a pleiotropic cell surface receptor that was originally identified based on its role in axon guidance during neuronal development, and subsequently shown to be important in the development of the lymphatic and immune systems. NRP2 can bind to multiple ligands and co-receptors to influence these multiple functional roles, including interaction with type 3 semaphorins and plexins to impact neural development, and also forms of vascular endothelial growth factor, especially VEGF-C which is involved in lymphogenesis.

Recent evidence suggests that there are high levels of NRP2 expression found on different immune cell types, which may play important roles in migration, antigen presentation, phagocytosis and cell-to-cell interactions. NRP2 is expressed in various cells of the immune system such as B cells, T-cells, NK cells, neutrophils, dendritic cells and macrophages, including alveolar macrophages. It plays an important role in the regulation of immune cell activation and migration including endosome maturation, the modulation of autophagy and efferocytosis. This suggests that NRP2 may be an important regulator of biological responses in a number of different disease settings with potential for therapeutic intervention.

Our team is collaborating with leading academic groups working on these pathways and we are excited to contribute to advancing the understanding of NRP2 biology and how it may play a role in certain diseases. We continue to research the ways in which NRP2 utilizes common mechanisms, including VEGFs and semaphorins, to regulate diverse pathways. We believe our growing evidence base of data on the functions of NRP2 will allow us to select and develop additional novel product candidates for various diseases with unmet need.