Who We Are


Chief Scientific Officer - Thais Sielecki, PhD

Chief Executive Officer

Thais Sielecki, PhD

Before becoming CEO at Veltion Therapeutics, Dr. Sielecki worked as Vice President, Preclinical Development of Cytokine PharmaSciences, Inc. a company focused on inflammatory disease and women's health through small molecule development and controlled release. At CPSI Dr. Sielecki ran programs in oncology, inflammation, and women’s health from early lead discovery through to Phase I and assisted in Phase II and III study design as her primary focus. As part of the management team, she was also a member of teams to manage product portfolio, in-licensing, intellectual property management, and company strategy. CPSI was successfully sold to Ferring in 2012.

Prior to CPSI, Dr. Sielecki worked at DuPont-Merck and Bristol-Myers Squibb as a Principle Research Scientist and continues to consult for pharmaceutical and biotech companies in the management and evaluation of early research, preclinical and early clinical studies. During over 30 years of research and development experience, Dr. Sielecki has been involved in over 40 preclinical and clinical research programs with multiple programs reaching marketing approval. Programs she has been closely involved in include CPSI-2364, CPSI-1306, Misopessc, c-VadTM, PilobucTM, DMP754, DMP802 among others. Her experience spans oncology, inflammation, women’s health, CNS diseases, and antibacterials with a strong background in drug delivery and controlled release delivery systems.

Dr. Sielecki has a PhD In medicinal chemistry from Colorado State University and completed a Post Doctoral research position at Stanford University. She has over 60 publications and patents over her career.

Constantinos Koumenis

Scientific Founder

Constantinos Koumenis, PhD

Dr. Constantinos (Costas) Koumenis received his B.S degree in Pharmacy with honors from the Aristotle University of Thessaloniki, Greece and his Ph.D. degree in Biochemistry from the University of Houston, TX. He then trained as a postdoctoral fellow in Radiation and Tumor Biology at Stanford University. His first faculty appointment was as Assistant Professor at Wake Forest University School of Medicine and then moved to the University of Pennsylvania School in Philadelphia, as Associate Professor in 2006. He is currently the Richard Chamberlain Endowed Professor and Vice-Chair for Research, in the Department of Radiation Oncology at the University of Pennsylvania. Dr. Koumenis also serves as the Associate Director for Translational Research of the Abramson Comprehensive Cancer Center at the University of Pennsylvania. For over 20 years, his scientific research interests have focused on the role of the tumor microenvironment on tumor progression, metastasis and resistance to therapy. He and his team have made original and seminal contributions to our understanding of the critical role for the Unfolded Protein Response (UPR) and Integrated Stress Response (ISR) in tumor progression and metastasis. In 2019, he co-founded Veltion Therapeutics with current CEO Dr. Thais Sielecki, to identify and develop novel agents which target the UPR and ISR as anti-tumor and anti-fibrotic agents. Dr. Koumenis has published over 120 manuscripts in high-impact journals and he is currently the Principal Investigator or co-PI on multiple research and training grants.

Constantinos Koumenis

Vice President, Research and Development

Chris Teleha, PhD

Before becoming VP R&D at Veltion Therapeutics, Dr. Teleha worked as Scientific Director at Janssen. a family of companies of Johnson & Johnson. His focus was enabling small molecule development and early process research and manufacturing/GMP scale-up. While at Janssen, achieving increasing levels of responsibility during his time, he was Scientific Integrator for API on several CMC teams for compounds in development. Early in his career at Janssen, he was integral to the research associated with mu/delta mixed opioid agonist/antagonist Viberzi™ and other projects within the company portfolio.

Prior to Janssen, Dr. Teleha worked at DuPont-Merck and Bristol-Myers Squibb as a Director, Discovery Scale-up and presently continues to pursue various interests as Founder of ICDS Consulting. During his 30 years of research and development experience, Dr. Teleha has lived in Belgium on a short term research assignment, awarded a Australian grant with Monash University to lecture on Process and Green Chemistry, and has been involved in a wide span of preclinical and clinical research programs in multiple therapeutic areas.

Dr. Teleha has a PhD in organic chemistry from the University of Rochester and completed post-doctoral research at The Ohio State University. He has co-authored and named co-inventor on over 40 publications/patents during his career.