Who We Are

Poseida brings together scientists, entrepreneurs, and inventors united behind one goal: using advanced gene engineering to change how diseases are treated.

We are a clinical-stage biopharmaceutical company leveraging our proprietary next-generation, non-viral gene engineering technologies to create ground-breaking, life-saving cell and gene therapies for patients with high unmet medical need.

We are using our broad gene engineering platform technologies to bring new and better treatments to patients with serious diseases — blood cancers like multiple myeloma, solid tumor cancers like prostate and breast cancer, and rare genetic diseases in the liver.


  • Beginning

    Poseida was established in 2015 as a spinout from parent company Transposagen, an early leader in the development of gene engineering technologies, also led by our founding CEO, Eric Ostertag, M.D., Ph.D. Dr. Ostertag, the first graduate of the University of Pennsylvania’s gene therapy program, is a pioneer in the field of cell and gene therapies.

  • Early Trials

    In 2017 the company presented pre-clinical data demonstrating tumor response in its first CAR-T product candidate, P-BCMA-101 in multiple myeloma, followed soon after by pre-clinical data for P-PSMA-101 in prostate cancer showing potent anti-tumor activity and persistent, durable responses. In December 2017, Poseida received a grant from The California Institute for Regenerative Medicine (CIRM) to support the Phase 1 clinical trial for P-BCMA-101. The first BCMA patient in the trial was dosed later that year.

  • Growing Pipeline

    Poseida completed a financing round in the spring of 2018 and later received an additional grant from CIRM to support our preclinical studies for P-PSMA-101 in prostate cancer. In November 2018, we received Regenerative Medicine Advanced Therapy (RMAT) designation from the U.S. Food and Drug Administration for P-BCMA-101 for the treatment of multiple myeloma and Orphan Drug designation in the year following.

  • Going Public

    We dosed the first patient in a Phase 1 clinical trial of our second product candidate, P-PSMA-101, in May 2020. Poseida completed a crossover financing round just prior to an initial public offering (IPO) in July 2020, going public on the Nasdaq under the ticker symbol PSTX. The company is currently listed on the Russell 2000 Index and the Nasdaq Biotech Index (NBI).

  • Key Milestones

    In 2021, the U.S. Food and Drug Administration cleared the Investigational New Drug (IND) application for Poseida’ s first fully allogeneic CAR-T product candidate, P-BCMA-ALLO1 for the treatment of multiple myeloma. We presented strong CAR-T data in a solid tumor indication with our P-PSMA-101 program. In October 2021, we announced a strategic collaboration with Takeda focused on developing non-viral in vivo gene therapy programs utilizing our proprietary genetic engineering platform technologies.

  • Looking Forward

    We are looking forward to advancing our programs in CAR-T and in gene therapies, including an off-the-shelf allogeneic CAR-T in BCMA and another in MUC1C, our first solid tumor product candidate with multiple potential targets. In addition to our pipeline of CAR-T product candidates across liquid and solid tumors, we are focused on developing gene therapies to treat rare diseases.


Mark J. Gergen - profile

Mark J. Gergen

Chief Executive Officer and Chairman
Johanna Mylet, C.P.A. - profile

Johanna Mylet, C.P.A.

Chief Financial Officer
Brent Warner - profile

Brent Warner

President, Gene Therapy
Devon J. Shedlock, Ph.D. - profile

Devon J. Shedlock, Ph.D.

Chief Scientific Officer, Cell Therapy
Kristin Martin - profile

Kristin Martin

Chief People and Administration Officer
Harry J. Leonhardt, Esq. - profile

Harry J. Leonhardt, Esq.

General Counsel, Chief Compliance Officer & Corporate Secretary
Lisa Portale - profile

Lisa Portale

Senior Vice President, Regulatory Affairs
Loren Wagner - profile

Loren Wagner

Senior Vice President, Global Operations
Karen Basbaum - profile

Karen Basbaum

Senior Vice President, Business Development
Jeffrey W. Winkelman, Ph.D., J.D. - profile

Jeffrey W. Winkelman, Ph.D., J.D.

Senior Vice President, Chief Patent Counsel

Board of Directors


Mark J. Gergen


Charles M. Baum, M.D., Ph.D.

Cynthia Collins

Luke Corning

Marcea Bland Lloyd, J.D.

John Schmid

Scientific Advisory Boards


Cell Therapy

Carl June, M.D.


Christine Brown, Ph.D.

Luca Gattinoni, M.D.

Jan Joseph Melenhorst, Ph.D.


Gene Therapy

George M. Church, Ph.D.


Ian E. Alexander, MBBS, Ph.D.

Julian Grünewald, M.D.

Mark A. Kay, M.D., Ph.D.

Mark A. Tracy, Ph.D.

Kathryn A. Whitehead, Ph.D.