Clinical Trial Failure or Delays: Clinical trials for Mereo's product candidates, particularly setrusumab, may not achieve their primary or secondary endpoints or may be significantly delayed, which would adversely affect their development and commercial prospects.

Regulatory Approval Uncertainty: Even if clinical trials are successful, Mereo may not obtain the necessary regulatory approvals from agencies like the FDA or EMA, or such approvals may come with significant restrictions, preventing or delaying market access.

Need for Additional Financing: Mereo is a clinical-stage company and will require substantial additional capital to fund its research, development, and potential commercialization efforts, which may not be available on favorable terms or at all, leading to potential dilution or cessation of operations.