Octreotide-LAR in later-stage autosomal dominant polycystic kidney disease (ALADIN 2): A randomized, double-blind, placebo-controlled, multicenter trial

Background Autosomal dominant polycystic kidney disease (ADPKD) is the most frequent genetically determined renal disease. In affected patients, renal function may progressively decline up to end-stage renal disease (ESRD), and approximately 10% of those with ESRD are affected by ADPKD. The somatostatin analog octreotide long-acting release (octreotide-LAR) slows renal function deterioration in patients in early stages of the disease. We evaluated the renoprotective effect of octreotide-LAR in ADPKD patients at high risk of ESRD because of later-stage ADPKD. Methods and findings We did an internally funded, parallel-group, double-blind, placebo-controlled phase III trial to assess octreotide-LAR in adults with ADPKD with glomerular filtration rate (GFR) 15–40 ml/min/1.73 m2. Participants were randomized to receive 2 intramuscular injections of 20 mg octreotide-LAR (n = 51) or 0.9% sodium chloride solution (placebo; n = 49) every 28 days for 3 years. Central randomization was 1:1 using a computerized list stratified by center and presence or absence of diabetes or proteinuria. Co-primary short- and long-term outcomes were 1-year total kidney volume (TKV) (computed tomography scan) growth and 3-year GFR (iohexol plasma clearance) decline. Analyses were by modified intention-to-treat. Patients were recruited from 4 Italian nephrology units between October 11, 2011, and March 20, 2014, and followed up to April 14, 2017. Baseline characteristics were similar between groups. Compared to placebo, octreotide-LAR reduced median (95% CI) TKV growth from baseline by 96.8 (10.8 to 182.7) ml at 1 year (p = 0.027) and 422.6 (150.3 to 695.0) ml at 3 years (p = 0.002). Reduction in the median (95% CI) rate of GFR decline (0.56 [−0.63 to 1.75] ml/min/1.73 m2 per year) was not significant (p = 0.295). TKV analyses were adjusted for age, sex, and baseline TKV. Over a median (IQR) 36 (24 to 37) months of follow-up, 9 patients on octreotide-LAR and 21 patients on placebo progressed to a doubling of serum creatinine or ESRD (composite endpoint) (hazard ratio [HR] [95% CI] adjusted for age, sex, baseline serum creatinine, and baseline TKV: 0.307 [0.127 to 0.742], p = 0.009). One composite endpoint was prevented for every 4 treated patients. Among 63 patients with chronic kidney disease (CKD) stage 4, 3 on octreotide-LAR and 8 on placebo progressed to ESRD (adjusted HR [95% CI]: 0.121 [0.017 to 0.866], p = 0.036). Three patients on placebo had a serious renal cyst rupture/infection and 1 patient had a serious urinary tract infection/obstruction, versus 1 patient on octreotide-LAR with a serious renal cyst infection. The main study limitation was the small sample size. Conclusions In this study we observed that in later-stage ADPKD, octreotide-LAR slowed kidney growth and delayed progression to ESRD, in particular in CKD stage 4. Trial registration ClinicalTrials.gov NCT01377246; EudraCT: 2011-000138-12.


ETHICS
This study will be conducted in accordance with the ethical principles that have their origin in the Declaration of Helsinki and that are consistent with Good Clinical Practice and the applicable laws and regulations.

Independent ethics committee
This protocol will be submitted for approval to the local ethics committee. This investigation will be implemented in full accordance to the local laws for the protection of patients in biomedical studies and of patient data.

Data protection
All acting parties declare to keep the patient's data confidential. The patient will be informed about his/her right to consent or to deny the transmission of any study-related concerning his/her state of health, quality of life parameters and health and labour parameters, to his/her treating physician by the investigator before, during and after closeout of this study.

Patient information and consent
The patient will receive two separate documents: the Patient Information Letter and the Patient Consent Form. The documents will provide a summary of the quality of life (QoL) and socio-economical investigation, including its purpose in easily understandable local language. The investigator will be available to answer any question giving the patient sufficient reflection time. If the patient decides to take part in the investigation, he will date and sign the consent form and receive a copy of the document from the investigator. At any time included in the study will be able to withdraw their consent without any future liabilities.

Investigator's responsibilities
Investigator's responsibilities related to ALADIN 2 trial are reported in the final protocol and subsequent amendments of each study. As far as the responsibilities referred to the administration of the two questionnaires are concerned, the clinical investigator will: a) be well acquainted with the investigation plan; b) endeavour to ensure an adequate recruitment of subjects; c) ensure that the subject has an adequate information to obtain informed consent; d) obtain and document informed consent; e) carry the primary responsibility for the accuracy, legibility and security of all documentation relevant to the investigation; f) ensure that the basic data are kept for the appropriate time (as required by national laws and regulation); g) be responsible for the supervision and assignment of duties to all responsible for the conduct and evaluation of the investigation in his/her department. The Clinical Monitor shall verify that Good Clinical Practice requirements are implemented. The study will be monitored by means of inspection of the following: a) patients enrolment in relation to observed inclusion criteria; b) signed and dated informed consent forms: c) adherence to he study protocol and respect of privacy for the patient; d) withdrawal of a patient and documentation of non conformity; e) all clinical trial requirements and documentation to which this study is linked (ALADIN 2 clinical trial).

BACKGROUND
Autosomal Dominant Polycystic Kidney Disease (ADPKD), the most common hereditary cystic renal disease, has an incidence of 1 in 800 live births and account for 7-10% of patients on dialysis in developed countries (1). ADPKD shows genetic heterogeneity, with two main genes implicated, the PKD gene 1 (85%-90% of the cases) and the PKD gene 2 (10-15% of the cases) which encode for proteins policystin 1 and policystin 2 respectively (1,2). Clinically, ADPKD is characterized by renal and extra renal manifestations (1). In the kidneys, multiple cysts grow from distal and collecting tubular epithelial cells producing progressive renal enlargement with relatively initial stable renal functions (3). Thereafter, both tubular and secondary interstitial damage lead to faster renal loss and end-stage renal disease (ESRD) in approximately half of all patients affected in their fifth or sixth decade of life (2,4). More than 50% of the patients display hepatic cysts derived from cholangiocyte proliferation and fluid secretion (5). Pancreatic and intestinal cysts as well as increased risk of aortic aneurysms, heart-valve defects and sudden death due to rupture of intracerebral aneurysms are extra-renal manifestations, too (6). The precise molecular pathogenic mechanisms of ADPKD are not completely understood, but experimental models in renal tubular cells suggest that defect in policystin 1 or policystin 2 carry out to decrease intracellular calcium and increase cAMP levels changing the cell toward a proliferative and secretor phenotype (7,8,9). Cysts growth and enlargement are mainly consequence of epithelial cells proliferation and fluid chloride secretion through apical channels dependent of cAMP (10,11). Likewise, for hepatic cyst development, the proposed mechanisms are linked to abnormalities in epithelial cell proliferation and secretion in response to high intracellular cAMP concentrations secondary to policystin defects (12). Patients with ADPKD, at similar levels of proteinuria and blood pressure control, do not seem to benefit to the same extent of ACE inhibitor therapy and have faster decline in glomerular filtration rate (GFR) compared with other chronic kidney diseases (13). Thus, in ADPKD renoprotective interventions -in addition to achieving maximal reduction of arterial blood pressure and proteinuria, and limiting the effects of other potential disease progression promoters (such as dyslipidemia, chronic hyperglycemia, or smoking) (14,15) -should also be specifically aimed to correct the dysregulation of epithelial cell growth, fluid secretion, and extracellular matrix deposition that is characteristic of this disease. Up to now, no specific therapies for ADPKD are available, but drugs like somatostatin, rapamycin, and tolvaptan targeting to growth and chloride secretions pathways are now being testing worldwide in some clinical trials (16,17). Somatostatin is an endogenous cycled polypeptide presents in two active forms (14 and 18 amino acids) with endocrine, paracrine and autocrine actions (18). The effects of somatostatin are pleiotropic depending on the tissue and the type of receptors it binds to. Five subtypes of somatostatin receptors have been described (sst1-sst5), but on the renal tubular epithelial cells, sst1 and sst2 receptors predominate. Of interest, it has been reported that somatostatin inhibits the increase in intracellular cAMP and chloride secretion induced by arginine-vasopressin hormone (AVH) in rectal glands of sharks (19,20). Octreotide, a synthetic analog of somatostatin with longer half-life and higher sst2 affinity than naive polypeptides (21), has been used with negligible side effects for longterm treatment of acromegaly (22) and some malignant tumors (23). Considering the inhibitory effect of somatostatin on cell proliferation and chloride secretion, we have performed some years ago a pilot prospective cross-over controlled study with long-acting somatostatin analog in patients with ADPKD and different degree of renal dysfunction (17). We found that in these patients, 6 month treatment with octreotide was safe, well tolerated, and slowed the time-dependent increase in total kidney volume to a significant extent compared to placebo. The net effect in kidney volume resulted from an action of the drug on cyst volume and on parenchyma volume (17). Moreover, more recent post-hoc analysis of the concomitant liver disease progression in the same ADPKD patients demonstrated a significant reduction in the total liver volume during octreotide treatment, not appreciably observed during placebo. The beneficial effect of octreotide has been then confirmed in rodent models of polycystic liver and kidney disease where the drug significantly reduced liver weight, cyst volume, hepatic fibrosis and mitotic indexes by reducing the cholangiocyte and serum cAMP levels (24). Moreover, in the untreated ADPKD patients enrolled in our study, computed tomography evaluation of disease progression showed that the ratio of faintly contrast-enhanced parenchyma volumereferred as intermediate parenchymaover total parenchyma volume strongly correlated with basal GFR and GFR changes during the observation period (25). The good safety profile of octreotide and the slowing of renal growth demonstrated in our short-term clinical study did suggest the feasibility of a randomized trial in larger series of ADPKD patients with normal renal function or mild renal insufficiency to verify whether long-term somatostatin treatment may eventually provide effective renoprotection. This trial -the ALADIN study -is ongoing and the planned ADPKD patients have been enrolled. So far, no particular side effects have been reported. More important, preliminary interim analysis of data from patients who reached 1 year treatment, confirmed the beneficial effect of octreotide in slowing the growth of total kidney volume compared to placebo. There is urgent need for renoprotection in ADPKD patients, particularly for those with more advanced renal dysfunction, for whom so far no clinical trials have been designed. The findings of the safety and potential benefit of octreotide in few patients with severe renal insufficiency observed in our initial pilot study (17) and the encouraging preliminary long-term effect results of octreotide on kidney growth, make worth investigating the efficacy of a longacting somatostatin (Octreotide LAR) in slowing or even halting the kidney enlargement and renal function decline in ADPKD patients with moderate/severe renal failure.

Primary
The primary objective of this study in the short-term (1-year) is to compare the effect of long acting somatostatin analogue (Octreotide LAR) versus placebo on total kidney volume (TKV) change (delta TKV) as assessed by spiral computed tomography (spiral CT) scan. (see paragraph 6.1.1). While in the Long-term (3-years) the objective will be to compare the effect of long-acting somatostatin analogue (Octreotide LAR) vs. placebo on the rate of GFR decline as assessed by serial measurements of the iohexol plasma clearance.

Secondary
The secondary objectives of this study is to compare, among the two groups, absolute and relative changes in renal and liver volume parameters (at month 0, 12 and 36) as well as in functional and biochemical parameters by quarterly clinical visits during the 36 month follow-up and To assess the safety profile of the somatostatin analogue.  7 and the Health and Labour Questionnaire (SF-HLQ) 9 . Data will be collected in an ad-hoc form and in parallel clinical and demographic data on the above subjects will be collected in the trial Case Report Form (CRF) of the ALADIN 2 study. At least 80 all consecutive patients will be selected after randomization. The Phase B of the study has an observational, prospective cohort design. Patients will be asked to fill in the questionnaires yearly (SF-36 V1 TM , only) and at the final study visit (both, SF-36 V1 TM and SF-HLQ). Data will be collected in an ad-hoc form and in parallel clinical and demographic data of the above subjects will be collected on the trial linked CRF of the ALADIN 2 study. Eligible patients can be identified among the subjects attending the Day Hospital of the Clinical Research Center for Rare Diseases Aldo e Cele Daccò of the IRCCS -Mario Negri Institute, who are enrolled in the above mentioned ongoing clinical trial in patients with non diabetic chronic kidney disease.

Number of patients
Due to the exploratory nature of the study a formal sample size assessment is not foreseen. However at least 80 patients with non diabetic chronic kidney disease will be adequate to provide a reliable measure of the eight QoL domains (1. physical functioning, 2. role-physical, 3. bodily pain, 4. general health, 5. vitality, 6. social functioning, 7. roleemotional, 8. mental health). The above sample size has been considered adequate also to provide a reliable measure of the societal and labour costs in the above kind of participants. A difference of 5 points or more is considered as clinically significant.

Inclusion criteria
The following inclusion criteria will be considered: a) patients with non diabetic chronic kidney disease;

Exclusion criteria
The following exclusion criteria will be considered: a) patients with diabetic chronic kidney disease; b) legal incapacity and/or the circumstances rendering the patient unable to understand the nature and the scope of the study. c) 24-h Urinary protein excretion rate >3g (suggestive of a concomitant glomerular disease that could benefit of specific therapy) d) Symptomatic urinary tract lithiasis or obstruction e) Uncontrolled diabetes mellitus (HbA1c >8%) or hypertension (systolic/diastolic BP >180/110 mmHg) f) Current urinary tract infection g) Symptomatic biliary tract lithiasis h) Active cancer i) Psychiatric disorders or any condition that might prevent full comprehension of the purposes and risks of the study l) Pregnancy, lactation or child bearing potential and ineffective contraception (estrogen therapy in post menopausal women should not be stopped)

Study Type
The Phase A of the study is an observational cross-sectional study. The phase B has an observational, prospective cohort design. Patient satisfying the inclusion/exclusion criteria will be provided with two questionnaires. Patient will be asked to fill in the informed consent and then the questionnaires. They will be assisted, if required, by an accompanying persons. Questionnaires will be rendered anonymous for data processing. The recruitment is expected to start in June 2013 and to end December 2014 for Phase A. Yearly, for phase B patients will be asked to fill in the questionnaire SF-36 V1 TM in order to evaluate changes in QoL; at clinical study closure, patients will be asked to fill in both questionnaires SF-36 V1 TM and SF-HLQ to assess changes in QoL and societal costs. In parallel to data-gathering by two previously mentioned questionnaires, demographic and clinical data will be collected in the CRF of the linked clinical trial.

Quality of life and societal cost evaluation
The primary aim of this study is to asses the QoL and the societal costs as described in the following.

Quality of life
The QoL (including physical functioning, role-physical, bodily pain, general health, vitality, social functioning, role-emotional and mental health) of all patients will be evaluate using the Version 1 of SF-36 (QoL SF-36 V1 TM Questionnaire) adjusted and validated in Italy 7 (see Enclosure A). For the Phase B of the study quantity and quality of life can be quantified by the quality-adjusted life year (QALY) 15,16 indicator to be used to assess the impact of healthcare intervention on an individual patient.

Social costs
Social costs include production losses due to the absence from work, reduced productivity, and reduced unpaid labour participation. Production losses of paid and unpaid labour will be assessed by means of the Short-Form-Health and Labour Questionnaire (SF-HLQ), of which existing translations are available for Italy 11 (see Enclosure B). The SF-HLQ Questionnaires allows to estimate indirect non-medical costs of productivity losses caused by absence from work due to health problems. Indirect costs are used in pharmacoeconomic research to perform an economic evaluation from societal perspective 9 .

Currency
Euro will be considered as currency for the evaluation of social costs.

Statistical analysis
As distributions of QoL scores are skewed 11 , the nonparametric Wilcoxon rank sum test will be applied. Scores will be expressed as a median and interquartile range. To compare the costs by clinical category, a multiple linear regression model will be used. Explorative analyses in pre-defined subgroups of patients (e.g. by gender) will be performed. Study results will be reported according to suggested guidelines 17 . A P value less than 0.05 (two tailed) will be considered to indicate statistical significance. All analyses will be carried out using SAS 9.1 (SAS Institute Inc., Cary, NC) and Stata 12 (StataCorp LP, College Station, Texas).

DATA COLLECTION
The scores of QoL Questionnaire SF36 V1 TM and indirect costs (missed days work, etc.) will be quantified by means of the Health and Labour Questionnaire and recorded on a paper data form and coded on a Excel file (Microsoft Office Excel 2003).

STUDY START
Expected Phase A and Phase B study are foreseen to start in March 2013. The study will be completed depending on study closure of ALADIN 2 trial.

OBJECTIVE
The general aim of the trial is to assess the efficacy of one year treatment with long-acting somatostatin analogue (Octreotide LAR) compared with placebo in slowing kidney and liver growth rate in patients with ADPKD and moderate/severe renal insufficiency (estimated GFR by MDRD 4 variables: 15-40 ml/min/1.73m2) and to assess whether and to which extent this translates into slower renal function decline over 3-year follow-up.

CONDITION INTERVENTION
After four weeks wash-out period from previous ACE inhibitors and AII receptor antagonist, eligible patients will be randomized to two treatment arms: 1. Telmisartan (one week 40 mg daily, followed by fifteen weeks treatment period with 80 mg daily); 2. Losartan (one week 50 mg daily, followed by fifteen weeks treatment period with 100 mg daily); At the end of the first treatment period with telmisartan or losartan, each patient will crossover to the other treatment.
After the second treatment period, there will be a four week recovery period.

Short-term (1-year)
To compare the effect of long acting somatostatin analogue (Octreotide LAR) versus placebo on total kidney volume (TKV) change (delta TKV) as assessed by spiral computed tomography (spiral CT) scan.

Long-term (3-years)
To compare the effect of long-acting somatostatin analogue (Octreotide LAR) vs. placebo on the rate of GFR decline as assessed by serial measurements of the iohexol plasma clearance.

Secondary
To compare, among the two groups, absolute and relative changes in renal and liver volume parameters (at month 0, 12 and 36) as well as in functional and biochemical parameters by quarterly clinical visits during the 36 month followup.

STUDY TYPE
A prospective, randomized, open label blinded end point (PROBE).

NUMBER OF PATIENTS TO RECRUIT
Due to the exploratory nature of the study a formal sample size assessment is not foreseen. However at least 80 patients with non diabetic chronic kidney disease will be adequate to provide a reliable measure of the eight QoL domains (1. physical functioning, 2. role-physical, 3. bodily pain, 4. general health, 5. vitality, 6. social functioning, 7. role-emotional, 8. mental health). The above sample size has been considered adequate also to provide a reliable measure of the societal and labour costs in non diabetic chronic kidney disease. A difference of 5 points or more is considered as clinically significant. STUDY PERIOD 32 weeks

SUMMARY OF ADVERSE EVENTS
Octreotide-LAR Placebo

SUMMARY OF SERIOUS ADVERSE EVENTS
Octreotide-LAR Placebo