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Why do clinical trials fail?

Updated: Jan 12, 2023

If you’re in the drug development industry you’ve certainly heard the daunting statistic that 90% of drug fail clinical trials after having successful preclinical studies. With the significant amount of time and money it takes to take a drug to market, a deeper understanding of possible reasons why drugs fail may aid in the strategic development of a drug and ensure that patients are getting the best treatments available.

Why Do Drugs Fail

A 2016 study analyzed Phase II and Phase III failures between 2013 and 2015 and found that 40% and 50% of failures were due to the drugs inability to demonstrate a meaningful benefit, 30% were due to unacceptable toxicity or side effects, 10%-15% were due to poor pharmacokinetic properties (interaction of the drug within the body), and 10% of failures were attributed to lack of commercial interest and poor strategic planning.

There are several reasons that drugs can fail to show clinical efficacy in late-stage clinical trials, many of which have to do with a flawed study design. Making sure the study has the proper statistical endpoint and having a properly powered study that accounts for patient dropout or insufficient enrollment from the start are two key aspects that can greatly impact the outcome of a study.

Patient opinions are another key to a successful trial and adding patient advocates to help in study design is vital. Often patients and physicians have different concerns when it comes to adverse events, which can lead to differences in the expected reported in the severity of these outcomes. Without proper consideration to patient opinions, a trial may not succeed. It is important to not rush into a Phase III trial without properly addressing any safety concerns that arose in the Phase II.

Trial recruitment has been a big factor in the success of clinical trials. Many obstacles exist in getting patients to enroll or stay enrolled in trials which include whether the hospital offers the trial, the distance to the trial, the amount of travel time, etc. Many of these issues are seemingly being addressed with decentralized clinical trials and it will be interesting to see if this helps the efficacy of trials in the coming years.

Strategic planning is essential, and failure to properly do so leads to around 10% of drug development failures. Issues can arise when a company decides to change the therapeutic focus or if there is poor study conduct. It is important to have a strong development plan with milestones defined through each stage of development. A diverse team made up of key opinion leaders can help evaluate and create the an efficient and optimal strategic plan for patient's needs and market trends.

How Can MEDSIR Help

One of MEDSIR’s main missions is to ensure that promising treatments makes it to patients. In order to accomplish this, MEDSIR is dedicated to helping healthcare companies develop the best strategy for their pipeline.

We can evaluate your pipeline and determine the best strategic planning to help position your molecule on the path to success. With a network of key opinion leaders, we will do competitive analysis to properly evaluate your molecule. In doing so we will work together to select the right unmet need, proper endpoints, most accurate statistical analysis, and appropriate site selection. Our team also focuses on the financial impact of each decision and will focus on speed of recruitment without compromising the scientific recruitment.

At MEDSIR we have a decade of experience in oncology clinical trials with a cross-functional structure that utilizes our network of KOLs to guide your pipeline. We would love to work together to help make sure your molecule is set up for success, so contact us to learn more!



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