Harout Semerjian is President and Chief Executive Officer of Geron Corporation, a clinical-stage biotechnology company advancing telomerase-targeted cancer therapies. Since joining in 2020, he has led the strategic development of Geron’s lead program, imetelstat, into late-stage clinical trials for hematologic malignancies, securing regulatory designations and partnerships to support global development. He has strengthened clinical infrastructure, expanded commercial planning, and maintained disciplined capital allocation to advance pivotal trials.
Previously, Semerjian was Executive Vice President and Chief Business Officer at Gilead Sciences, leading business development, global strategy, and alliances, and played key roles in acquisitions expanding oncology, hematology, and cell therapy portfolios. He held senior roles at Calyxt, Zafgen, and worked as a senior biotech analyst, giving him deep expertise in scientific evaluation, capital markets, and corporate strategy.
The 100 CEOs featured here reflect the diversity and complexity of modern oncology leadership. In 2025, some lead the world’s largest cancer institutions; others guide specialized societies or emerging innovators. What unites them is responsibility: for millions of patients, for the integrity of science, and for the future direction of cancer care globally.
This list is not a celebration of power, but a recognition of stewardship, accountability, and impact – and of the leaders whose choices continue to shape the fight against cancer. For the many deserving individuals not mentioned in this list, we will continue to acknowledge, honor and elevate your voices in our daily publications from across the world.
See the full list of The 100 Most Influential CEOs in Oncology in 2025, and stay tuned for other special category nominations.
