Oral insulin has been pursued for decades, so far with limited success Over the last decades, several strategies to circumvent the barriers to oral delivery of insulin have been pursued, but so far with limited success. The main technical obstacles are degradation of the insulin in the stomach and the intestine combined with a low absorption over the intestinal wall, leading to low levels of insulin reaching the blood stream. This insight provides an overview of the currently most advanced oral insulins projects. Majority of development candidates have not progressed beyond short-term trials Limited activities from established diabetes companies With the exception of Novo Nordisk, currently in phase 1 with an oral basal insulin analogue, established diabetes companies have not disclosed oral insulin activities. Yet, both Eli Lilly and Sanofi have expressed a clear interest in the field and have ongoing scouting activities to identify potential development candidates externally. Former diabetes player Bristol-Myers Squibb (BMS) has an ongoing collaboration with the Indian company Biocon on the short-acting oral human insulin IN-105 initiated in late 2012. However, the status on the clinical activities is uncertain, and with BMS’ decision to divest its diabetes assets to AstraZeneca, BMS might have limited interest in the asset. Clinical activities by smaller companies based on established formulation principles Several insulin delivery systems have been explored to protect insulin from enzymatic degradation and facilitate absorption over the intestinal wall. Biocon’s technology is based on formulation of the insulin molecule to limit enzymatic degradation and enhance uptake over the intestinal membrane providing a short-acting insulin product. Oramed’s approach is based on formulation of human insulin with absorption enhancers and enzyme inhibitors. These activities have been ongoing for more than two decades. Oshadi’s Icp concept is a combination of insulin, proinsulin and c-peptide loaded on silica nanoparticles that are suspended in oil. Extrawell has done phase 3 trials in China with an oral formulation of porcine insulin, but no results have been published. Published phase 2 results indicated a good bioavailability. New phase 1 trials based on human insulin seem to progress very slowly.
No long-acting insulin analogues from competitors in clinical development To date, development activities by competitors have been solely based on human insulin with a pharmacokinetics (PK) profile suggesting short duration of action. Depending on the formulation approach, PK profiles have shown either rapid onset of action or delayed release (onset of action within 1–3 h), but still with duration of action similar to short-acting insulin. However, the variable effects reported with oral insulin in fasted state will be further impacted by food interaction after concomitant food intake, making it very difficult to develop oral short-acting insulin with a predictable profile. Currently, Novo Nordisk is the only company pursing development of a long-acting oral insulin
More sophisticated delivery concepts are in early preclinical testing One such example is form Rani Therapeutics. The approach is to take advantage of the body's natural digestive processes to activate a pill or capsule to perform a series of functions. When swallowed, the environment in the intestine triggers the capsule to present small dissolvable needles preloaded with active drug. The needles can push into the intestinal wall. Once lodged there, they can deliver the drug, where after they dissolve. The company is in initial pre-clinical testing of this concept. Initiation of long-term efficacy and safety trials are still to be seen The majority of the companies covered in this overview have been working on oral insulin projects for several years. The limited successes so far indicate that activities based on formulation principles are not sufficient to overcome the barriers for oral insulin delivery. More advanced approaches, such as the use of designed insulin analogues combined with the right delivery formulation or the more sophisticated approach, may be needed to provide convincing results in long-term trials. Despite established diabetes companies all have interest in the field, Novo Nordisk is the only company with oral insulin in clinical development with the potential to be first to market in the this challenging field.
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