Background
Phase III, double-blind, placebo-controlled RCT. N=410 patients with advanced, low-grade or intermediate-grade pancreatic neuroendocrine tumors (pNET) with documented radiologic progression within the prior 12 months. Randomized 1:1 to everolimus vs placebo, both with best supportive care. Open-label everolimus offered to patients progressing on placebo. 49% had prior SSA therapy; 28% had prior cytotoxic chemotherapy.
Interventions and follow up
Arm A: Everolimus 10 mg orally once daily + best supportive care (n=207)
Arm B: Placebo + best supportive care (n=203)
Primary endpoint: Progression-free survival (intention-to-treat)
Median follow-up: Not reported (NR) in primary publication
Arm B: Placebo + best supportive care (n=203)
Primary endpoint: Progression-free survival (intention-to-treat)
Median follow-up: Not reported (NR) in primary publication
Results
PFS: 11.0 vs 4.6 months, HR 0.35 (95% CI 0.27–0.45), P<.001 (65% risk reduction)
PFS at 18 months: 34% vs 9%
OS: Not significantly improved (final analysis confounded by 85% crossover from placebo)
PFS at 18 months: 34% vs 9%
OS: Not significantly improved (final analysis confounded by 85% crossover from placebo)
Adverse events
Most common (any grade): Stomatitis 64% vs 17%, rash 49% vs 10%, diarrhea 34% vs 10%, fatigue 31% vs 14%, infections 23% vs 6%.
Grade 3–4: Anemia 6% vs 0%, hyperglycemia 5% vs 2%.
Grade 3–4: Anemia 6% vs 0%, hyperglycemia 5% vs 2%.
Conclusions
Everolimus 10 mg significantly prolonged PFS in progressive advanced pNET (11.0 vs 4.6 months, HR 0.35, P<.001). RADIANT-3 established everolimus as a standard of care in progressive pNET alongside sunitinib, as the first large randomized mTOR inhibitor trial in this tumor type.
Key Limitations
Open-label crossover in 85% of placebo patients after progression confounded OS; no significant OS benefit was demonstrated in the final analysis. PFS as the sole primary endpoint raises surrogate validity concerns. Grade 1–2 stomatitis was very common (64%) and impacts tolerability and quality of life. Poorly differentiated (grade 3) and functional pNET were excluded, limiting generalizability. The magnitude of OS benefit independent of everolimus is unknown.
Clinical Context
Everolimus (Afinitor) was FDA-approved for progressive pNET in 2011 based on RADIANT-3. It is one of two approved targeted agents for pNET alongside sunitinib (phase III trial by Raymond et al, NEJM 2011). Disease control (stable disease) rather than objective response (ORR ~5%) is the dominant pattern. ENETS and ESMO guidelines list everolimus as a standard-of-care option for SSTR-negative or SSTR-low pNET where PRRT is not optimal.