McPhail, Ellen Darcy

Background: Beside fibril-forming proteins, amyloid deposits contain other proteins which can influence organ toxicity, disease initiation and clearance. We investigated the association between the amyloid plaque proteomic signature of diagnostic renal biopsies from patients achieving deep and sustained hematologic remissions and renal organ response in AL amyloidosis. Methods: Retrospective study of newly diagnosed AL amyloidosis patients between 2010-2020. Patients were eligible if; (1) they had a baseline renal biopsy which had undergone laser micro-dissection and mass spectrometry, (2) were assessable for renal response [RenR, non-selective proteinuria ≥1g /24 hours, predominantly albumin], (3) were not on renal replacement therapy and did not experience renal progression within 3-months of diagnosis and (4) had RenR measurements, at least twice annually in the first year from treatment and annually thereafter. Patients who did not obtain a renal complete response (RenCR) required a hematologic very good partial response (VGPR) or better within 6 months of treatment initiation, sustained for a minimum of 6 months. Hematological and renal responses were graded according to consensus criteria. Overrepresentation analyses of differentially expressed proteins were performed using the WebGestalt 2019 and the reactome pathway database. A false detection rate corrected p value <0.05 was used to identify significantly overrepresented proteins and pathways. Results: We defined two organ response categories, to capture the extreme ends of the spectrum: renal suboptimal responders (n=24), patients for whom the best renal response was ≤partial response (RenPR), and renal complete responders (n=29), patients who obtained a RenCR at best response. Overall, the median follow-up was 6.7 years (IQR: 5.4-9.2), 6.6 years (IQR: 5.4-8.1) for complete responders, and 8.4 years (IQR: 6.1-11.3) for suboptimal responders. Between renal suboptimal responders and complete responders there was no significant difference in median age (63 vs 63 years, p=0.7), lambda light chain isotype (66% vs 79%, p=0.3), first-line therapy received and renal stage (Stage III: 14% vs 8%, p=0.9). The median time to RenCR was 52-months (IQR: 31-63). Protein pathways over-represented in renal complete responders included 14-3-3 proteins (YWHAG, YWHAH, YWHAQ, YWHAZ), early components of the complement cascade and complement regulatory proteins (C3, C4A, C4B, C8A, complement factor H), keratins, cytoskeletal proteins (tubulin, actin, filamen) and collagen IV. Protein pathways over-represented in renal suboptimal responders included terminal/effector components of the complement cascade (C5, C6, C8B, C9), amyloid signature proteins (ApoA1 and E, vitronectin, clusterin), proteoglycans (heparan sulfate proteoglycan), transgelin and metallopeptidase inhibitor 3. Proteins with the highest-fold increase in renal complete responders included serine protease inhibitor (SERPINA3) and F-box and leucine rich repeat protein (FBXL6), 9.0 x 106 & 7.7-fold, respectively. Proteins with the highest-fold increase in renal suboptimal responders included complement 6 and 8B, 3.5 & 3.6-fold, respectively. Conclusion: This is the first study to identify proteomic determinants of organ response in AL amyloidosis. Molecular chaperones involved in protein aggregate homeostasis, such as the 14-3-3 proteins are upregulated in renal complete responders, similar to what we have shown in our prior work. This suggests that organ responders may have a more favorable microenvironment which “primes” them for organ response after the amyloidogenic light chain has been cleared from the circulation. Renal suboptimal responders (≤RenPR) have elevated levels of terminal complement proteins including membrane attack complex proteins and reduced levels of early components or complement regulatory proteins, which may be responsible for reno-toxic and reno-protective effects, respectively.

7067 Background: High intensity induction with regimens such asDA-EPOCH-R, CODOX-M/IVAC-R and HyperCVAD are often used for young patients with DHL/THL despite no overall survival (OS) benefit compared to R-CHOP. Reports on the application of CODOX-M/IVAC-R are subject to selection bias as only young fit patients can tolerate it. We aimed to investigate outcomes difference between CODOX-M/IVAC-R and DA-EPOCH-R in patients ≤ 60 years with DHL/THL diagnosed via FISH. Methods: Retrospective review of DHL/THL patients from the Mayo Clinic diagnosed between July15th 2010-October19th 2023 treated with CODOX-M/IVAC-R or DA-EPOCH-R at age of up to 60 years. Event free survival (EFS) was defined as time from diagnosis to progression, relapse, next line of treatment or death from any cause. Results: 113 patients were included; CODOX-M/IVAC-R (N=49) and DA-EPOCH-R (N=64). Patient and disease characteristics are in table. 80% (N=39) achieved CR on end of treatment (EOT) PET CT with CODOX-M/IVAC-R compared to only 58% (N=37) with DA-EPOCH-R. CODOX-M/IVAC-R was associated with superior EFS on univariate (HR=0.54, 95%CI=0.31-0.97) and multivariable analysis adjusted for age, BCL2 vs BCL6 translocation and receipt of consolidation ASCT (aHR=0.53, 95%CI=0.29-0.95), however, there was no significant influence on OS (aHR=0.97, 95%CI=0.50-1.91). At a median follow-up of 5.3 years and 3.3 years for the CODOX-M-IVAC and DA-R-EPOCH group respectively; EFS was superior in the CODOX-M/IVAC-R group having 1, 2 and 5 years EFS of 68.3%, 64.1 and 61.5% respectively compared to 52.4%, 48.9% and 39.5% respectively in the DA-EPOCH-R group (p=0.035). 33%(16/49) of the CODOX-M/IVAC-R patients had R/R disease (No CR on EOT PET CT or relapsed) with a median OS of 10.3 months compared to 33.7 months in the R/R DA EPOCH-R group (54%, 35/64). Number of patients who were able to receive salvage ASCT, CAR T and Allo-SCT were 5, 17 and 4 respectively in the DA EPOCH-R group compared to 1, 6 and 3 patients respectively in the CODOX-M/IVAC-R group. None died of regimen toxicity in both groups. 19% underwent ASCT consolidation after CR with initial induction (11 patients in each group); no OS was noticed however consolidation with ASCT was associated with increased EFS regardless of the induction regimen with best outcomes being in the CODOX-M/IVAC-R group (P=0.0072). Conclusions: Our study showed that young patients with DHL/THL who received CODOX-M/IVAC-R had superior EFS compared to DA-EPOCH-R with no OS benefit. CODOX-M/IVAC-R can spare patients receiving more subsequent therapies. Patients who have R/R disease following CODOX-M/IVAC-R have poor outcomes. [Table: see text]

AbstractPeripheral T‐cell lymphoma (PTCL) is a clinically heterogeneous group that represents 10%–15% of all lymphomas. Despite improved genetic and molecular understanding, treatment outcomes for PTCL have not shown significant improvement. Although Janus kinase‐2 (JAK2) plays an important role in myeloproliferative neoplasms, the critical role of JAK isoforms in mediating prosurvival signaling in PTCL cells is not well defined. Immunohistochemical analysis of PTCL tumors (n = 96) revealed high levels of constitutively active JAK3 (pJAK3) that significantly (p < 0.04) correlated with the activation state of its canonical substrate STAT3. Furthermore, constitutive activation of JAK3 and STAT3 positively correlated, at least in part, with an oncogenic tyrosine phosphatase PTPN11. Pharmacological inhibition of JAK3 but not JAK1/JAK2 significantly (p < 0.001) decreased PTCL proliferation, survival and STAT3 activation. A sharp contrast was observed in the pJAK3 positivity between ALK+ (85.7%) versus ALK‐negative (10.0%) in human PTCL tumors and PTCL cell lines. Moreover, JAK3 and ALK reciprocally interacted in PTCL cells, forming a complex to possibly regulate STAT3 signaling. Finally, combined inhibition of JAK3 (by WHI‐P154) and ALK (by crizotinib or alectinib) significantly (p < 0.01) decreased the survival of PTCL cells as compared to either agent alone by inhibiting STAT3 downstream signaling. Collectively, our findings establish that JAK3 is a therapeutic target for a subset of PTCL, and provide rationale for the clinical evaluation of JAK3 inhibitors combined with ALK‐targeted therapy in PTCL.