Caplin 2014 — CLARINET Trial

Citation: Caplin ME, Pavel M, Ćwikła JB, et al; CLARINET Investigators. Lanreotide in Metastatic Enteropancreatic Neuroendocrine Tumors. N Engl J Med. 2014;371(3):224-233. doi:10.1056/NEJMoa1316158.

Study design

• Randomised, double-blind, placebo-controlled, multinational, phase 3 trial (CLARINET; NCT00353496; 48 centres, 14 countries). 204 patients randomised (101 lanreotide / 103 placebo), June 2006–April 2013.
• Population: advanced, well- or moderately-differentiated, nonfunctioning, somatostatin- receptor-positive enteropancreatic NETs, grade 1 or 2 (Ki-67 <10%), with documented disease-progression status. Primary tumour origin: pancreas (42-48%), midgut (33-39%), hindgut (3-11%), unknown/other. 96% had no tumour progression in the 3-6 months before randomisation (i.e., predominantly a stable-disease population).
• Intervention: extended-release lanreotide (Autogel/Depot) 120 mg SC every 28 days vs placebo, for up to 96 weeks.
• Primary endpoint: progression-free survival (PFS), centrally assessed (RECIST v1.0).

Key findings

• Median PFS: not reached (lanreotide) vs 18.0 months (placebo); HR for progression or death 0.47 (95% CI 0.30–0.73); p<0.001 — a 53% reduction in risk of progression/death.
• 24-month PFS rate: 65.1% (lanreotide) vs 33.0% (placebo).
• Treatment effect was broadly consistent across predefined subgroups (tumour origin, grade, hepatic tumour volume ≤25% vs >25%), with wide confidence intervals in the smaller subgroups (e.g. hindgut origin, n=14).
• No significant between-group difference in overall survival or quality of life — complicated by crossover (placebo patients with progression could enter an open-label lanreotide extension study) and the generally long natural history of these tumours.
• Chromogranin A normalisation (≥50% reduction from an elevated baseline): 42% (lanreotide) vs 5% (placebo).
• Safety: adverse-event rates similar overall (88% vs 90%), but treatment-related AEs more common with lanreotide (50% vs 28%) — most commonly diarrhoea (26% vs 9%), abdominal pain (14% vs 2%), and cholelithiasis (10% vs 3%).

Limitations

• 96% of patients had stable disease at baseline — the trial does not address efficacy specifically in patients with actively progressive disease at treatment initiation.
• No OS benefit shown, but the trial was neither powered nor able (given crossover and slow-growing tumour biology) to detect one — absence of OS benefit should not be read as absence of clinical benefit.
• Only nonfunctioning tumours were enrolled (unlike PROMID, which included some functioning/ carcinoid-syndrome tumours) — CLARINET does not independently speak to lanreotide’s antiproliferative effect in functioning tumours, though the authors note PROMID’s own subgroup analysis found similar antiproliferative effects regardless of functional status.
• Broader Ki-67 range (up to 10%, i.e. into grade 2) and larger hepatic tumour volumes than PROMID — by the authors’ own framing this was a deliberate design choice to extend PROMID’s narrower (largely grade-1, low-tumour-burden) findings, which somewhat limits apples-to-apples comparison between the two trials.

Relevance

Closes the primary-literature gap flagged in Small Bowel Neuroendocrine Tumors (NETs)‘s Open items for lanreotide/CLARINET — that page previously only narratively summarized this trial via a textbook chapter, without specific PFS figures. The precise numbers here (median PFS not reached vs 18.0 months; HR 0.47) should replace the previously unsourced qualitative statement. Complements Rinke 2009 - PROMID Trial (octreotide, narrower population — near-exclusively low-grade midgut tumours) as the second pivotal SSA antiproliferative trial, and the two together underpin current guideline-level SSA recommendations across a broader enteropancreatic NET population than either trial alone covers.