The use of lanreotide in polycystic kidney disease: a single-centre experience

Renal ciliopathies: promising drug targets and prospects for clinical trials

INTRODUCTION

Renal ciliopathies represent a collection of genetic disorders characterized by deficiencies in the biogenesis, maintenance, or functioning of the ciliary complex. These disorders, which encompass autosomal dominant polycystic kidney disease (ADPKD), autosomal recessive polycystic kidney disease (ARPKD), and nephronophthisis (NPHP), typically result in cystic kidney disease, renal fibrosis, and a gradual deterioration of kidney function, culminating in kidney failure.

AREAS COVERED

Here we review the advances in basic science and clinical research into renal ciliopathies which have yielded promising small compounds and drug targets, within both preclinical studies and clinical trials.

EXPERT OPINION

Tolvaptan is currently the sole approved treatment option available for ADPKD patients, while no approved treatment alternatives exist for ARPKD or NPHP patients. Clinical trials are presently underway to evaluate additional medications in ADPKD and ARPKD patients. Based on preclinical models, other potential therapeutic targets for ADPKD, ARPKD, and NPHP look promising. These include molecules targeting fluid transport, cellular metabolism, ciliary signaling and cell-cycle regulation. There is a real and urgent clinical need for translational research to bring novel treatments to clinical use for all forms of renal ciliopathies to reduce kidney disease progression and prevent kidney failure.

Structural insights into the activation of somatostatin receptor 2 by cyclic SST analogues

The endogenous cyclic tetradecapeptide SST14 was reported to stimulate all five somatostatin receptors (SSTR1-5) for hormone release, neurotransmission, cell growth arrest and cancer suppression. Two SST14-derived short cyclic SST analogues (lanreotide or octreotide) with improved stability and longer lifetime were developed as drugs to preferentially activate SSTR2 and treat acromegalia and neuroendocrine tumors. Here, cryo-EM structures of the human SSTR2-Gi complex bound with SST14, octreotide or lanreotide were determined at resolutions of 2.85 Å, 2.97 Å, and 2.87 Å, respectively. Structural and functional analysis revealed that interactions between β-turn residues in SST analogues and transmembrane SSTR2 residues in the ligand-binding pocket are crucial for receptor binding and functional stimulation of the two SST14-derived cyclic octapeptides. Additionally, Q1022.63, N2766.55, and F2947.35 could be responsible for the selectivity of lanreotide or octreotide for SSTR2 over SSTR1 or SSTR4. These results provide valuable insights into further rational development of SST analogue drugs targeting SSTR2.

Hepatic Cyst Infection During Use of the Somatostatin Analog Lanreotide in Autosomal Dominant Polycystic Kidney Disease: An Interim Analysis of the Randomized Open-Label Multicenter DIPAK-1 Study

Introduction and Aims

The DIPAK-1 Study investigates the reno- and hepatoprotective efficacy of the somatostatin analog lanreotide compared with standard care in patients with later stage autosomal dominant polycystic kidney disease (ADPKD). During this trial, we witnessed several episodes of hepatic cyst infection, all during lanreotide treatment. We describe these events and provide a review of the literature.

Methods

The DIPAK-1 Study is an ongoing investigator-driven, randomized, controlled, open-label multicenter trial. Patients (ADPKD, ages 18–60 years, estimated glomerular filtration rate 30–60 mL/min/1.73 m²) were randomized 1:1 to receive lanreotide 120 mg subcutaneously every 28 days or standard care during 120 weeks. Hepatic cyst infection was diagnosed by local physicians.

Results

We included 309 ADPKD patients of which seven (median age 53 years [interquartile range: 48–55], 71% female, median estimated glomerular filtration rate 42 mL/min/1.73 m² [interquartile range: 41–58]) developed eight episodes of hepatic cyst infection during 342 patient-years of lanreotide use (0.23 cases per 10 patient-years). These events were limited to patients receiving lanreotide (p < 0.001 vs. standard care). Baseline characteristics were similar between subjects who did or did not develop a hepatic cyst infection during lanreotide use, except for a history of hepatic cyst infection (29 vs. 0.7%, p < 0.001). Previous studies with somatostatin analogs reported cyst infections, but did not identify a causal relationship.

Conclusions

These data suggest an increased risk for hepatic cyst infection during use of somatostatin analogs, especially in ADPKD patients with a history of hepatic cyst infection. The main results are still awaited to fully appreciate the risk–benefit ratio.

ClinicalTrials.gov identifier

NCT 01616927.

Electronic supplementary material

The online version of this article (doi:10.1007/s40264-016-0486-x) contains supplementary material, which is available to authorized users.

Efficacy of 4 Years of Octreotide Long-Acting Release Therapy in Patients With Severe Polycystic Liver Disease

OBJECTIVE

To observe the effect on total liver volume (TLV) on and off therapy in selected symptomatic patients with autosomal dominant polycystic kidney disease (ADPKD) or autosomal dominant polycystic liver disease (PLD) who received octreotide long-acting release (OctLAR) for up to 4 years.

PATIENTS AND METHODS

Twenty-eight of 42 participants in a prospective 2-year clinical trial of OctLAR (40 mg monthly) consisting of double-blind, randomized (year 1) and open-label treatment (year 2) phases reenrolled in a 2-year open-label extension (OLE) study after being off OctLAR a mean of 8.3 months (original study: July 1, 2007, through June 30, 2013). Participants underwent magnetic resonance imaging at baseline, years 1 and 2, reenrollment, and study completion. Primary end point: change in TLV; secondary end points: changes in total kidney volume, glomerular filtration rate, quality of life (QoL), safety, vital signs, and laboratory parameters.

RESULTS

Twenty-five participants (59.5%) completed the OLE. Off therapy, TLVs increased a mean ± SD of 3.4%±8.2% per year; after resuming therapy, TLVs decreased a mean ± SD of -4.7%±6.1% per year. Despite regrowth off treatment, overall reductions were observed, with a median (interquartile range) TLV of 4047 mL (3107-7402 mL) at baseline and 3477 (2653-7131 mL) at study completion (-13.2%; P<.001) and with improved health-related QoL. Total kidney volumes increased, and glomerular filtration rates declined from 58.2 mL/min to 54.5 mL/min (n=16) in patients with ADPKD on therapy from baseline to study completion.

CONCLUSION

Therapy with OctLAR over 4 years in selected patients with symptomatic PLD arrested PLD progression, alleviating symptoms and improving health-related QoL. Discontinuation led to organ regrowth.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00426153.