One-Year Outcomes of the Open-Label Extension of CHIASMA OPTIMAL, a Phase 3 Study of Oral Octreotide Capsules in Acromegaly

Oral Octreotide: A Review of Recent Clinical Trials and Practical Recommendations for Its Use in the Treatment of Patients With Acromegaly

OBJECTIVE

Acromegaly is characterized by chronic growth hormone (GH) and insulin-like growth factor-I (IGF-I) hypersecretion, often caused by a GH-secreting pituitary adenoma. Surgery remains first line, but medical therapy is essential if surgery is contraindicated, does not achieve remission, or does not prevent recurrence despite apparent surgical remission. Oral octreotide capsules (OOC) that combine octreotide with a transient permeability enhancer technology are the first oral somatostatin receptor ligand (SRL) approved in the US for acromegaly.

METHODS

We review the literature and clinical trial data of OOC for patients with acromegaly and discuss clinical assessment of OOC use, potential drug-drug interactions, drug initiation, dose titration, and monitoring of drug efficacy and tolerability.

RESULTS

Four pivotal clinical trials involving a total of 238 patients with acromegaly treated with OOC effective suppression of serum GH and IGF-I levels, maintenance of disease control, decreased breakthrough symptoms and symptomatic improvement with noninferiority of OOC to injectable SRLs (iSRLs) in maintaining biochemical response. Additionally, the safety profile of OOC is comparable to that of iSRLs. Most patients who completed the clinical trials of OOC have also expressed preference to oral compared to iSRL administration.

CONCLUSION

OOC is an effective treatment option for patients with acromegaly who previously responded to iSRLs, with the benefits of avoiding injection-related side effects. This article provides a review of the pharmacology, safety, and efficacy and offers practical recommendations on utilization of OOCs to treat iSRL-responsive patients with acromegaly.

Oral delivery of therapeutic peptides and proteins: Technology landscape of lipid-based nanocarriers

The oral administration of therapeutic peptides and proteins is favoured from a patient and commercial point of view. In order to reach the systemic circulation after oral administration, these drugs have to overcome numerous barriers including the enzymatic, sulfhydryl, mucus and epithelial barrier. The development of oral formulations for therapeutic peptides and proteins is therefore necessary. Among the most promising formulation approaches are lipid-based nanocarriers such as oil-in-water nanoemulsions, self-emulsifying drug delivery systems (SEDDS), solid lipid nanoparticles (SLN), nanostructured lipid carriers (NLC), liposomes and micelles. As the lipophilic character of therapeutic peptides and proteins can be tremendously increased such as by the formation of hydrophobic ion pairs (HIP) with hydrophobic counter ions, they can be incorporated in the lipophilic phase of these carriers. Since gastrointestinal (GI) peptidases as well as sulfhydryl compounds such as glutathione and dietary proteins are too hydrophilic to enter the lipophilic phase of these carriers, the incorporated therapeutic peptide or protein is protected towards enzymatic degradation as well as unintended thiol/disulfide exchange reactions. Stability of lipid-based nanocarriers towards lipases can be provided by the use to excipients that are not or just poorly degraded by these enzymes. Nanocarriers with a size <200 nm and a mucoinert surface such as PEG or zwitterionic surfaces exhibit high mucus permeating properties. Having reached the underlying absorption membrane, lipid-based nanocarriers enable paracellular and lymphatic drug uptake, induce endocytosis and transcytosis or simply fuse with the cell membrane releasing their payload into the systemic circulation. Numerous in vivo studies provide evidence for the potential of these delivery systems. Within this review we provide an overview about the different barriers for oral peptide and protein delivery, highlight the progress made on lipid-based nanocarriers in order to overcome them and discuss strengths and weaknesses of these delivery systems in comparison to other technologies.