22 November, 2017

Bridging studies - Why do researchers switch rodent strains?

By Travis Rothrock

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Selecting the right model and rodent strain for your oncology studies can maximize the chances of success. However, there is an ever-increasing portfolio of available models and strains that may perform better than existing ones and may be more optimal for specific study purposes.

Increasing investigators are seeking to bridge from an existing rodent strain to another for their oncology preclinical efficacy and pharmacology studies. The short-term barriers associated with switching strains can appear complex and daunting, but another strain may actually be the key to the success of your oncology preclinical program.

Be sure to understand how you can benefit from switching to a new oncology rodent strain.

ONCOLOGY R2G2.jpgSwitching strains can be the key to success in oncology 

1. Alternative characteristics; Different rodent strains have different characteristics that may be inherently more suitable to certain types of assays. For instance, the R2G2 mouse (a Rag2/IL2rg double knockout lacking natural killer cells) is sought out by researchers for its increased immunodeficiency and lower sensitivity to the effects of radiation compared to other available strains.

2. Enhanced strain options; An ever-expanding portfolio of strain options has meant that newly developed strains may have attractive attributes that could be more suitable for certain types of oncology models and studies. For instance, in the past decade, there have been additional strains that demonstrate differences in radiation sensitivity, have varying levels and types of immunodeficiency, or offer varying capacity for engraftment and/or humanization, as well as genetically engineered strains. In short, new strains are continually being developed and may perform better than an existing strain. Furthermore, testing across multiple strains can provide a level of assurance that there is broader applicability of the drug under investigation

3. Maximizing research efficacy; Maximization of preclinical research and development goals by taking the time to identify the proper strain. While a certain strain may have been used historically, this does not mean that it is the most appropriate current choice. The right strain can translate to quicker go/no go decisions, especially if there is an increased uptake and growth rate of engrafted cells. The most appropriate strain also allows for rigorous evaluation of target validity and offers the best possible opportunity for predicting clinical efficacy and addressing clinical questions further down the development path.

4. Cost savings; Savings in time, money, and resources by utilizing the optimal strain for your studies. These benefits can be realized by a reduction in study length, better-quality and reproducible data, reduced animal use, and potentially more desirable animal behavior characteristics.

It is also important to consider the potential pitfalls of switching to a new strain. Nevertheless, with appropriate up-front planning and research on the strain, including a review of publication references, the risks associated with switching can be managed and/or minimized.

Discover some best practices for bridging studies to generate data and validate a new strain.

The importance of an integrated approach

Bridging studies play an important role in preclinical drug development, since they provide important information that can prevent the need to repeat entire study programs. The basis of these studies is that the existing strain serves as the positive control and its data is bridged to the data generated for the new strain.

Learn more about the importance of bridging studies when switching strains.

By adhering to best-practices for general study design considerations and engaging in early discussions with experienced partners or collaborators, it is possible to enhance the potential success of the oncology preclinical program. From our comprehensive online resources, through to our model selection consultants and study directors– talk to us talk to us about your oncology portfolio needs from start to finish.

To learn more about the 'Best practices on bridging studies' download this informative e-book. 

[E-book] Best practices on bridging studies 

Category // Research models and services, Oncology, Travis Rothrock