Gilead Sciences Inc.’s Chief Medical Officer, Merdad Parsey, MD, PhD, will leave the company early next year. He will continue as CMO until the first quarter of 2025 and support this transition over the next several months while the company looks for a successor.

“On behalf of everyone at Gilead, I want to thank Merdad for his significant contributions as our Chief Medical Officer over the last five years. These were pivotal years for the company as we worked to strengthen and diversify the portfolio, and Merdad played a fundamental role in our success,” said Daniel O’Day, Chairman and CEO, Gilead. “We have more than doubled our portfolio under Merdad’s leadership, and with 54 ongoing clinical trials across virology, oncology, and inflammation, we are well positioned to build on our success for the future.”

Parsey joined Gilead in November 2019 and is responsible for overseeing the company’s global clinical development and medical affairs organizations. During his tenure, he led the growth of the development organization, specifically with the advancement of treatments in virology and the establishment of Gilead’s oncology pipeline and therapeutics.

This news comes after a difficult several months for Giliad—including several late-stage failures and development discontinuations. Specifically, cancer drug candidate Trodelvy has suffered a string of late-stage defeats.

In 2021, Trodelvy received accelerated approval from the FDA for treating locally advanced or metastatic urothelial cancer in patients who had previously undergone platinum-containing chemotherapy and an anti-PD-L1 agent. However, in May 2024, the antibody-drug conjugate (ADC) did not meet the main goal in its Phase III confirmatory trial. Additionally, Trodelvy failed the Phase III Evoke-01 study in non-small cell lung cancer (NSCLC) in January 2024.

Gilead faced challenges with another cancer treatment, the anti-CD47 antibody magrolimab, which the company stopped developing in April 2024 following persistent setbacks. Initially intended for myelodysplastic syndromes, Gilead had to halt the Phase III ENHANCE study in July 2023 after interim analysis indicated futility.

Disappointing magrolimab data also led Gilead to terminate the Phase III ENHANCE-2 study in acute myeloid leukemia in September 2023, and the ENHANCE-3 study was also discontinued earlier this year.

Magrolimab underwent multiple regulatory pauses. The first occurred in January 2022 due to serious adverse events flagged by the FDA, with the hold being lifted in April 2022. The candidate was then placed on partial hold in August 2023 and again in February 2024.