17th International Conference on Malignant Lymphoma, Palazzo dei Congressi, Lugano, Switzerland, 13 - 17 June, 2023.

Abstract

Background: Total metabolic tumor volume (TMTV) and maximum standardized uptake value (SUVmax) may improve upon standard 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET-CT)-based assessment during treatment. We report the association of TMTV and SUVmax response by interim PET (PET2) on survival outcomes in patients with primary refractory DLBCL (prDLBCL) and early relapsing DLBCL (erDLBCL). Methods: Adult patients with prDLBCL (less than a complete response at EOT or progression during treatment) or erDLBCL (CR at EOT with a relapse within 12 months) between 2005 and 2019 and seen at Mayo Clinic Rochester were included. The % change (Δ) from baseline to PET2 (after 2 cycles of 1L immunochemotherapy) of TMTV and maximum SUV uptake (SUVmax) were measured. A PET segmentation threshold of 1.5 liver mean SUV + two standard deviations with a minimum volume constraint of 0.5 mL was utilized (MIM Software, Inc., Cleveland OH, USA) with manual input as needed. Functional spline analysis showed a ΔSUVmax decline ≥65% and a ΔTMTV decline ≥75% at PET2 were associated with improved OS and determined threshold for further analysis. Results: 131 patients with prDLBCL or erDLBCL, 131 had complete PET-CT data available (N = 79 prDLBCL, N = 52 erDLBCL). Median baseline TMTV was 939.5 cm3 (range 13.1–6840.4) in prDLBCL and 670.4 cm3 (0.9–5464.5) in erDLBCL (p = 0.01). Baseline median SUVmax was 22.2 (3.1–52.6) in prDLBCL and 19.1 (2.0–49.7) in erDLBCL (p = 0.02). The 2-year estimated OS rate was 21% (95% CI: 13–34) for prDLBCL and 58% (95% CI: 45–75) for erDLBCL. At a median follow up of 77.6 months, 81 patients had died. Among all patients, Two-year OS rate was 53% (95% CI: 42–67) for patients with a PET2 ΔSUVmax decline ≥65% compared to 15% (95% CI: 7–29) for patients with a PET2 ΔSUVmax decline <65% (p < 0.001) (Figure A). PrDLBCL had a 2-year OS rate of 48% (95% CI: 31–74) for a ΔSUVmax ≥65% compared to 7% (95% CI: 2–21) for patients with a ΔSUVmax <65% (p < 0.001)(Figure B), which captured 58% of prDLBCL patients (N = 46). Among all patients, 2-year OS rate was 43% (95% CI: 34–54) for patients with a ΔTMTV ≥75% compared to 5% (95% CI: 1–35) for patients with a ΔTMTV <75% (p < 0.001) (Figure C). All patients with a ΔTMTV <75% had prDLBCL. PrDLBCL had a 2-year OS rate of 28% (95% CI: 18–44) for a ΔTMTV ≥ 75% (Figure D). The outcomes for ΔSUVmax <65% and ΔTMTV <75% at PET2 remained significant in a cox regression model when adjusted for IPI and bulky disease (>10 cm). Encore Abstract - previously submitted to ASCO 2023 Keywords: Aggressive B-cell non-Hodgkin lymphoma, PET-CT Conflicts of interests pertinent to the abstract. M. J. Maurer Employment or leadership position: Exact Sciences - immediate family member Consultant or advisory role: Genmab; Adaptive Biotechnologies Stock ownership: Exact Sciences Research funding: Morphosys; Bristol-Myers-Squibb; Roche/Genentech; Genmab J. Paludo Consultant or advisory role: Abbvie Research funding: Karyopharm; Biofourmis J. R. Cerhan Consultant or advisory role: Bristol-Myers Squibb/Celgene; Protagonist Therapeutics Research funding: NanoString Technologies; Celgene; Genentech; Genmab Other remuneration: Uncompensated relationship: Regeneron T. E. Witzig Consultant or advisory role: Tornado Therapeutics; Salarius Pharmaceuticals Honoraria: Curio Science Research funding: Celgene; Acerta Pharma; Kura Oncology; Acrotech Biopharma; Karyopharm Therapeutics T. M. Habermann Consultant or advisory role: Celgene; Kite/Gilead; MorphoSys; BeiGene; Loxo Oncology Research funding: Genentech; Sorrento; Celgene Other remuneration: Data Monitoring Committee: Tess Therapeutics; SeaGen, Eli Lilly and Co Y. Wang Employment or leadership position: Merck - immediate family member Consultant or advisory role: Loxo; Incyte; Innocare; TG Therapeutics; Kite, A gilead company; Lilly; Janssen; BeiGene Stock ownership: Merck - immediate family member Honoraria: Kite, A Gilead Company Research funding: InnoCare; Incyte; Novartis; Genentech; Loxo; MorphoSys; Genmab G. S. Nowakowski Consultant or advisory role: Celgene; MorphoSys; Genentech; Selvita; Debiopharm Group; Kite/Gilead; TG Therapeutics; Kymera; Karyopharm Therapeutics; Ryvu Therapeutics; Bantham Research funding: Celgene; NanoString Technologies; MorphoSys