Advancements in genomics and cancer precision medicine have improved our ability to differentiate cancers by their genetic mutations. These advancements, in turn, have fueled efforts concerning precision oncology, in which therapies are selected to target cancers based on their genetic mutations. These innovative treatments are commonly referred to as targeted therapies.1
Box. Standard Clinical Trials
Phase 1: often concerns dose escalation or dose finding with an assessment of dose-limiting toxicity
Phase 2: single arm, to evaluate drug efficacy and safety
Phase 3: randomized, controlled trial to test efficacy and safety vs standard-of-care arm. The results could lead to FDA approval for a new treatment, which usually concerns 1 cancer type. The process to get a drug FDA approved is lengthy and expensive.
The historical use of phase 1 to 3 trials for oncology drug approval was based on the tumor site of origin and the tumor’s histology. Clinical trials have been adjusted to target tumor-specific biomarkers regardless of the tumor type and histology. See Box for definitions of clinical trial phases.
Because it would be challenging to investigate biomarkers based on current trial design, there is a new framework called the master protocol. Master protocol refers to a single design developed to evaluate multiple hypotheses to improve efficiency and establish uniformity based on the presence of specific biomarkers, not tumor types.2
The 3 types of new protocols include basket trials, umbrella trials, and platform trials,1 as seen in the Table.
As oncology nurses, we are excited about the constantly changing landscape of cancer care, as our patients are surviving and often thriving. However, we have much to learn to keep our practices current. These novel clinical trial formats will allow survival advantages and more inclusive enrollment of patients with cancer. The formats can be complicated, time-consuming, and need careful planning. We must carefully analyze the results and know how to interpret the data and the design. You must be well informed before counseling your patients and families. This article gives a brief overview of the types of clinical trials, so I encourage you to review the referenced articles and learn more.
Table. Master Protocol Framework of Clinical Trials
- Assesses same treatment in several diseases or disease subtypes
- Mainly used in oncology; may involve patients with cancers affecting different organs but carrying same alteration
- Patients not enrolled by tumor type
- Having a specific tumor biomarker is typical for eligibility
- Assesses efficacy of drug against tumor biomarker
- Single arm, based on prior knowledge of biomarker
- Includes rare cancer types
- Needs confirmation with larger trial for approval
- Single tumor type with multiple different biomarkers
- Assesses efficacy of multiple drugs with patient receiving those that target their specific biomarker
- Used for cancers with different biomarkers, eg, lung and breast cancer
- Screens and enrolls a greater number of patients based on multiple biomarkers; allowed in any cancer type
- Improves possibility of benefits from target therapy
- Requires several study arms
- Must include many participants
- Follow-up of participants must be long term and active
- Evaluates multiple hypotheses in single protocol; design can be complicated
- Randomized and usually without termination date
- Compares multiple arms simultaneously or one after the other
- During trial, arms can be added or discontinued according to trial rules
- Leads to more rapid evaluation of drug
- Can modify drug dosage and sample size based on ongoing results
- Difficult to perform due to requirement of rapid and long-term follow-up
- Complex statistical analyses required to conduct trial. Practitioners often are not familiar with methodology.
References
- Park JJH, Siden E, Zoratti MJ, et al. Systematic review of basket trials, umbrella trials, and platform trials: a landscape analysis of master protocols. Trials. 2019;20(1):572. doi:10.1186/s13063-019-3664-1
- Park JJH, Hsu G, Siden EG, Thorlund K, Mills EJ. An overview of precision oncology basket and umbrella trials for clinicians. CA Cancer J Clin. 2020;70(2):125-137. doi:10.3322/caac.21600