Biomarkers of response to treatment in acromegaly

Acromegaly: diagnostic challenges and individualized treatment

INTRODUCTION

Acromegaly is due in almost all cases to a GH-secreting pituitary tumor. GH and IGF-1 excesses lead to its multi-system clinical manifestations and comorbidities. Acromegaly is under-diagnosed and typically presents with advanced disease. When early or mild, clinical recognition and biochemical confirmation are especially challenging. Individualized treatment may optimize patient outcome.

AREAS COVERED

This review covers challenges to diagnosing acromegaly and reviews therapies for acromegaly with a focus on those aspects that can be individualized.

EXPERT OPINION

The first step in diagnosing acromegaly is recognizing it clinically. To improve this, increase awareness and education of the general population and healthcare professionals about the acromegaly phenotype is needed. Once suspected clinically, IGF-1 measurement is the initial step in making the biochemical diagnosis. GH may be < 1.0 µg/L after oral glucose suppression in early/mild cases. GH and IGF-1 should be considered in concert. Providers should be aware of conditions that can alter GH and IGF-1 levels and each assay's performance. An individualized treatment approach is best employed. Surgery is preferred as initial treatment and medical therapy as initial adjuvant therapy. In individualizing therapy, the advantages and disadvantages of each option and predictors of response to them should be considered.

IGF-I levels during standard Lanreotide dose predicts biochemical outcome of high-frequency regimen in acromegaly

INTRODUCTION

First-generation somatostatin receptor ligands (fg-SRLs) are the cornerstone of acromegaly treatment. Additional benefits were shown using high dose (HD) or high frequency (HF), relatively short-term regimens. Although several predictors of response to standard dose (SD)-fg-SRLs were reported, outcome biomarkers for HF administration are not yet available. Here, we aimed to identify predictors of response to long-term HF-fg-SRLs.

PATIENTS AND METHODS

A retrospective study was performed on 102 patients, treated with Lanreotide. Patients not controlled at 12 months of SD-Lanreotide (120 mg/28 days) were switched to HF-Lanreotide (120 mg/21 days) for additional 12 months.

RESULTS

Twenty-eight patients were controlled at 6 months of SD-Lanreotide (27.4%); 35 patients were controlled at 12 months of treatment (34.3%). Out of 67 patients treated with HF- Lanreotide, 18 (26.9%) were controlled at 6 months of treatment and remained controlled until 12 months. Both during SD and HF-Lanreotide administrations, IGF-I levels were reduced during the first six months of treatment (p < 0.001), without further significant reduction between 6 and 12 months of therapy. Response at 12 months of SD-Lanreotide was predicted by IGF-I reached at six months of SD-Lanreotide (p = 0.024). Response at 12 months of HF-Lanreotide treatment was predicted by IGF-I levels reached at six months of SD-Lanreotide treatment (p = 0.04) and six months of HF-Lanreotide treatment (p = 0.01).

CONCLUSION

Our results demonstrated that initial IGF-I levels during SD-Lanreotide predicted the biochemical outcome after 12 months of HF-Lanreotide. Patients in whom HF-Lanreotide did not normalize IGF-I after 6 months of treatment remained uncontrolled 12 months after starting this regimen.

Oral octreotide capsules for acromegaly treatment: application of clinical trial insights to real-world use

INTRODUCTION

Acromegaly is a rare endocrine disorder usually caused by a benign growth hormone‒secreting pituitary adenoma. Surgical adenoma resection is typically the first line of treatment, and medical therapy is used for patients with persistent disease following surgery, for adenoma recurrence, or for patients ineligible for, or declining, surgery. Approved somatostatin receptor ligands (SRLs) have been limited to injectable options, until recently. Oral octreotide capsules (OOC) are the first approved oral SRL for patients with acromegaly.

AREAS COVERED

We review published reports and provide case study examples demonstrating practical considerations on the use of OOC. Using two hypothetical case scenarios, we discuss current treatment patterns, breakthrough symptoms and quality of life (QoL), efficacy of SRLs, OOC dose titration, evaluation of OOC treatment response, and incidence and management of adverse events.

EXPERT OPINION

OOC are an option for patients with acromegaly including those who experience breakthrough symptoms, who have preference for oral therapies, or other reasons for declining injectable SRLs. OOC have been associated with improved patient-reported QoL measures compared with those reported for lanreotide and octreotide. Continued real-world experience will determine whether OOC, alone or in combination with other therapies, provides further advantages over current injectable acromegaly treatments.