Phase 3 Trial Results Support Octreotide Capsules as First Oral Acromegaly Treatment

green and blue pills spilling from bottle
Capsules left lying on table, with open pill bottle
Oral octreotide capsules may be a potential therapeutic alternative to monthly injections for adults with acromegaly.

Oral octreotide may represent a new treatment alternative for patients with acromegaly, whose current treatment options include only injectable therapies and surgery, according to phase 3 trial data intended to be presented at the annual meeting of the Endocrine Society (ENDO 2020).

The Octreotide Capsules Versus Placebo Treatment in Multinational Centers (OPTIMAL; Identifier: NCT03252353) study included 56 patients aged ≥18 years with active acromegaly. Participants were randomly assigned to receive treatment with octreotide or placebo for 36 weeks, with the option to enter an extension period of open-label treatment with the study drug.

The researchers assessed the efficacy of octreotide by monitoring maintained biochemical response, defined as insulin-like growth factor-1 (IGF-1) levels ≤1.0 times the upper limit of normal. Safety and tolerability of the medication were also examined, and secondary end points included time to loss of IGF-1 response, growth hormone (GH) response (GH level <2.5 ng/mL), and need for rescue with somatostatin receptor ligand injections.

The active treatment met the primary end point of maintained biochemical response (P =.008), with 58% of patients who received octreotide maintaining IGF-1 response (mean levels at 0.97 times the upper limit of normal) compared with 19% of patients in the placebo group (mean levels at 1.69 times the upper limit of normal).

All secondary end points were also met. Compared with individuals in the placebo group, significantly more patients who received octreotide maintained GH response at week 36 (30% vs 78%, respectively; P =.001), and rescue therapy was required in fewer octreotide-treated patients (68% vs 25%, respectively). Moreover, median time to loss of IGF-1 response was 16 weeks for the placebo group but was not reached in the 36-week period for the active-treatment group (P <.0001); only 2 patients who received placebo did not meet the criteria for loss of response at any point during the trial.

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Octreotide was safe and well tolerated and no new or unexpected safety findings were reported. Nearly all patients experienced ≥1 treatment-emergent adverse event, but most were mild to moderate in intensity. A large majority of patients (90%) opted to enter the open-label extension period.

Taken together, the investigators suggested that these results support oral octreotide capsules as a potential therapeutic alternative to monthly injections for adults with acromegaly.

Disclosure: Chiasma, Inc. supported the OPTIMAL trial. All study authors declared affiliations with the pharmaceutical industry, including Chiasma. Please see the original reference for a full list of authors’ disclosures.

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Samson SL, Nachtigall LB, Fleseriu M, et al. Results from the phase 3, randomized, double-blind, placebo-controlled CHIASMA OPTIMAL study of oral octreotide capsules in adult patients with acromegaly. J Endocr Soc. 2020;4(suppl 1).