Lipase Inhibitor Development

The Background 

Lipases are a class of digestive enzymes responsible for digesting dietary lipids into fatty acids and glycerols for absorption. Inhibition of lipase can help treat obesity by preventing dietary fats from being absorbed and therefore reducing overall caloric intake and supporting weight management efforts.

For the development of a novel lipase inhibitor, it is essential to assess the activity of any candidate compound in a physiologically relevant environment as the compound must remain active in the complex environment of the GI tract. Therefore, Aelius Biotech’s model gut was used to assist in the development of a new class of lipase inhibitors.

Figure 1: Schematic representation of lipid digestion by pancreatic lipase and absorption of glycerol and fatty acids in the small intestine

The Model

Orlistat, developed by Roche in 1983, is an OTC human pancreatic lipase inhibitor. Orlistat was used as a positive control in our models. In order to investigate the efficacy of inhibitors in the presence of food, a pork and chicken pie was digested in the Aelius Model Gut with and without orlistat. Glycerol release was measured across the 3h time course as an indicator of fat digestion. As expected, the data showed substantial inhibition of glycerol release when orlistat was present when compared to the orlistat control demonstrating effective lipase inhibition (Figure 3).

Figure 2: Schematic representation of lipase inhibition, blocking fat digestion and subsequent glycerol and fatty acid absorption. Undigested lipids continue through the digestive tract into the colon and are excreted in the faeces.
Figure 3: Free glycerol release from 172g Marks and Spencer's Pork and Chicken Pie during 180 min of simulated digestion with the inclusion of 120mg Orlistat. Gastric phase (0-60 min), small intestinal phase (60-180 min)

The Problem

Client X had developed a novel lipase inhibitor with strong inhibition in isolated biochemical assays and had committed to a clinical trial. However, they had concerns about non-specific binding in the complex environment of the human digestive tract that could impact the activity in vivo (Figure 4).

Figure 4: Schematic representation of compound X binding to the food matrix, preventing lipase inhibition, allowing lipid digestion and glycerol and fatty acid absorption in the small intestine.

The Solution

The lipase activity was assessed in the same manner as previously described and Compound X showed no inhibition of glycerol release when compared to the vehicle-only control (Figure 5).

Figure 5: Free glycerol release from 172g Marks and Spencer's Pork and Chicken Pie during 180 min of simulated digestion with the inclusion of Compound X. Gastric phase (0-60 min), small intestinal phase (60-180 min)
Figure 5: Free glycerol release from 172g Marks and Spencer's Pork and Chicken Pie during 180 min of simulated digestion with the inclusion of Compound X. Gastric phase (0-60 min), small intestinal phase (60-180 min)

Conclusion

The Aelius Model Gut was used to demonstrate that lipase inhibitor compound X was inactivated in the presence of a meal. Unfortunately, Client X had already invested in a costly clinical trial, where their candidate ultimately showed no efficacy- as predicted by the Aelius Model Gut. This outcome highlights the importance of evaluating a compound’s efficacy in biorelevant environments, early in the development process. Had Client X utilised our models earlier, we could have identified this issue upfront, enabling them to redesign their compound to address the problem before moving forward with clinical trials.

Post a comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

We use cookies to give you the best experience.