Abstract 1121P
Background
Based on the KEYNOTE-028 trial, pembrolizumab is thought as a promising anti-tumor treatment for patients with carcinoid tumors and pancreatic neuroendocrine tumors (NET). Soluble programmed death-ligand 1(sPD-L1) may have immunosuppressive activity; however, the role of soluble markers in NET patients is still unclear. This study aimed to evaluate the prognostic value of sPD-L1 and soluble transforming growth factor-β (sTGF-β) in patients with non-functioning NET or pheochromocytomas/paragangliomas.
Methods
The study population consisted of 34 patients who received everolimus as a systemic treatment for non-functioning NETs, pheochromocytoma, or extra-adrenal paragangliomas (NCT01152827, Oh, D.Y., et al. (2012). Cancer 118(24): 6162-6170.). Plasma sTGF-β and sPD-L1 levels were measured using an enzyme-linked immunosorbent assay in the pre-everolimus treatment blood samples.
Results
The median sPD-L1 level was 5.36 ng/mL (range, 1.47-9.25 ng/mL). The median sTGF-β level was 21.97 ng/mL (9.03-34.91 ng/mL). Baseline sTGF-β was positively correlated with baseline sPD-L1, regardless of pathology (pearson’s r=0.659). There was no difference in patient characteristics according to the baseline sTGF-β level or sPD-L1 level. Patients with low sTGF-β level (<26.12 ng/mL) at baseline showed better progression-free survival (PFS) than those with high sTGF-β level (22.73 months vs. 12.97 months, p=0.019). Similarly, patients with low sPD-L1 level (<6.65 ng/mL) at baseline tended to have longer PFS than patients with high sPD-L1 level (18.97 months vs. 7.37 months, p=0.095). In multivariate analysis, the prognostic value of baseline sTGF-β for PFS retained its significance in patients with non-functioning NET (Hazard ratio 6.04, 95% confidential interval 1.13-32.38, p=0.036).
Conclusions
In non-functioning NETs, sPD-L1 at baseline was positively correlated with sTGF-β. sTGF-β before everolimus treatment confers a prognostic value for PFS in non-functioning NET patients treated with everolimus.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Seoul National University Hospital.
Disclosure
D. Oh: Financial Interests, Advisory Board: AstraZeneca; Financial Interests, Advisory Board: Novartis; Financial Interests, Advisory Board: Genentech/Roche; Financial Interests, Advisory Board: Merck Sereno; Financial Interests, Advisory Board: Bayer; Financial Interests, Advisory Board: Taiho; Financial Interests, Advisory Board: ASLAN; Financial Interests, Advisory Board: Holozyme; Financial Interests, Advisory Board: Zymeworks; Financial Interests, Advisory Board: BMS/Celgene; Financial Interests, Advisory Board: BeiGene; Financial Interests, Advisory Board: Basilea; Financial Interests, Advisory Board: Turning Point; Financial Interests, Research Grant: AstraZeneca; Financial Interests, Research Grant: Novartis; Financial Interests, Research Grant: Array; Financial Interests, Research Grant: Eli Lilly; Financial Interests, Research Grant: Servier; Financial Interests, Research Grant: BeiGene; Financial Interests, Research Grant: MSD; Financial Interests, Research Grant: Handok. All other authors have declared no conflicts of interest.