Siham Ceballos

Siham Ceballos bridges deep science with global execution, transforming breakthrough ideas into therapies that change lives. With a career spanning the full spectrum of pharmaceutical development — from discovery to global launch and venture creation — she combines scientific rigor, strategic leadership, and a focus on real-world impact.

Siham began her career as a scientist, earning a PhD in molecular and cellular onco-biology and completing postdoctoral research in aging science. Her work on TGF-beta signaling and the discovery of the p63 gene family advanced understanding of cancer progression and cellular senescence.

Transitioning into leadership, she built and scaled global medical affairs organizations at companies including Pfizer, Novartis, Celgene, Alnylam, and Mayne Pharma, supporting development from phase 1 through pivotal trials and leading eight successful product launches across oncology, hematology, rare diseases, CNS, and aging-related diseases.

As COO at Rejuveron, Siham established portfolio strategy, drove fundraising efforts, incorporated new biotech entities, and accelerated programs toward IND-enabling studies and first-in-human trials. She continues to advise biotech founders, guide technology transfer offices, and evaluate early-stage startups as an Innosuisse Innovation Expert.

Based in Switzerland and working globally, Siham brings a unique blend of scientific depth, operational excellence, and strategic foresight to help organizations scale and succeed.