Cancer clinical trials can fail for various reasons, some common reasons for the failure of cancer clinical trials include:

Inadequate Patient Recruitment: Clinical trials require a sufficient number of participants to generate meaningful and statistically significant results. Challenges in recruiting and retaining eligible participants can lead to delays or premature termination of trials, particularly if the target population is small or difficult to reach.

Lack of Efficacy: Despite promising preclinical or early-phase results, some treatments may not demonstrate the expected efficacy or benefit when tested in larger and more diverse patient populations. The complexity of cancer biology, tumor heterogeneity, and variability in treatment response among individuals can contribute to the failure of treatments to show significant clinical benefit.

Safety Concerns: Unforeseen safety issues or unexpected adverse events may arise during the course of a clinical trial, leading to concerns about the safety profile of the treatment. Serious adverse events or toxicity can prompt the suspension or early termination of trials to ensure the safety of participants.