Oral druggable space beyond the rule of 5: insights from drugs and clinical candidates

Doak BC, Over B, Giordanetto F, Kihlberg J.

Chem Biol. 2014 Sep 18;21(9):1115-42. doi: 10.1016/j.chembiol.2014.08.013.

The rule of 5 (Ro5) is a set of in silico guidelines applied to drug discovery to prioritize compounds with an increased likelihood of high oral absorption. It has been influential in reducing attrition due to poor pharmacokinetics over the last 15 years. However, strict reliance on the Ro5 may have resulted in lost opportunities, particularly for difficult targets. To identify opportunities for oral drug discovery beyond the Ro5 (bRo5), we have comprehensively analyzed drugs and clinical candidates with molecular weight (MW) > 500 Da. We conclude that oral drugs are found far bRo5 and properties such as intramolecular hydrogen bonding, macrocyclization, dosage, and formulations can be used to improve bRo5 bioavailability. Natural products and structure-based design, often from peptidic leads, are key sources for oral bRo5 drugs. These insights should help guide the design of oral drugs in bRo5 space, which is of particular interest for difficult targets.

Want to know more about this publication?

Contact our scientists

medicinal chemistry

Drug Discovery

We are running our own state-of-the-art Drug Discovery Chemistry facilities in Germany with the option for process research chemistry, upscaling, kilolab production…

performance chemicals

Material Science

We create performance chemicals to enhance new materials, plastics, coatings, dyes & inks, cosmetics, flavors and many more research and industrial applications…


Looks interesting?

As a leading contract research organization in discovery chemistry and custom synthesis, Taros provides comprehensive solutions to meet our clients’ needs from diverse branches and applications

Our experienced chemists practice a pragmatic culture and customer-centric approach in order to exceed project expectations, despite challenges, bridging very narrow timelines. They are trained to consider economic, safety and ecological boundaries and conditions laid out for all stages of the project, starting from the development of synthetic routes to…