Gertz, Morie A

ABSTRACT Disease Overview AL amyloidosis is a clonal plasma cell disorder in which fragments of immunoglobulin light or heavy chain are deposited in tissues. Clinical features depend on organs involved but can include HFpEF, nephrotic syndrome, hepatic dysfunction, peripheral/autonomic neuropathy, and “atypical smoldering multiple myeloma or MGUS.” Diagnosis Tissue biopsy stained with Congo red demonstrating amyloid deposits with apple‐green birefringence is required. Organ biopsy is not required in 85% of patients. Verification that amyloid is composed of immunoglobulin light chains is mandatory. Prognosis N‐terminal pro–brain natriuretic peptide (NT‐proBNP or BNP), serum troponin T (or I), and difference between involved and uninvolved immunoglobulin free light chain values are used to classify patients into four stages; 5 year survivals are 82%, 62%, 34%, and 20% respectively. Therapy All patients with a systemic amyloid syndrome require therapy to prevent deposition of amyloid in other organs and prevent progressive organ failure. Current first line therapy with the best outcome is daratumumab, bortezomib, cyclophosphamide, and dexamethasone. The goal of therapy is a ≥ VGPR. In patients failing to achieve this depth of response, options for consolidation include pomalidomide, stem cell transplantation, and venetoclax. T‐cell redirecting therapies, both bispecific antibodies and car T, show high level activity and may soon become standard second‐line therapy. Future Challenges Delayed diagnosis remains a major obstacle to initiating effective therapy prior to the development of end‐stage organ failure. An antibody to deplete deposited κ fibrils has reported benefit in patients with cardiomyopathy.

Abstract Waldenström macroglobulinemia (WM) is characterized by recurrent MYD88 and CXCR4 mutations, whose prognostic value in patients treated with chemoimmunotherapy remains unclear. Moreover, the typically prolonged progression-free survival (PFS) correlates inconsistently with overall survival (OS), underscoring the importance of examining other surrogates. Progression of disease within 24 months (POD24), an established early end point, delineates functionally high-risk patients in other indolent lymphomas. This international study evaluated 253 patients receiving frontline fixed-duration bendamustine-rituximab (BR), a common chemoimmunotherapy for WM. At a median follow-up of 5.9 years, 5-year PFS and OS were 65% and 87%, respectively; 5-year PFS was similar between MYD88L265P (90%) and MYD88wild-type (WT) subcohorts (64% each; P = .4). Among 89 patients with known CXCR4 status, the subcohort with CXCR4mutation (28%) had shorter PFS (median 3.3 vs 8.8 years; hazard ratio [HR], 2.8; P = .0036) and OS (HR, 2.6; P = .036) compared with CXCR4WT. POD24 occurred in 11.5% of patients who demonstrated inferior subsequent OS (5-year OS, 71% vs 86%; HR, 3.1; P = .005) and higher mortality (standardized mortality ratio [SMR], 3.7), unlike the non-POD24 group, whose mortality was comparable to the matched general population (SMR, 1.1). In conclusion, BR is effective irrespective of the MYD88 status, but CXCR4 mutations and POD24 portend worse outcomes. Patients without POD24 represent a cohort with distinctly favorable outcome.

Abstract Castleman disease (CD) is a heterogeneous group of lymphoproliferative disorders anatomically classified by distribution (unicentric CD [UCD], oligocentric CD [oligoCD], or multicentric CD [MCD]). Human herpes virus 8–negative MCD is called idiopathic MCD (iMCD), which includes clinical subtypes with varying phenotypes and responses: TAFRO (thrombocytopenia, anasarca, fever, renal dysfunction and/or reticulin fibrosis, and organomegaly), IPL (idiopathic plasmacytic lymphadenopathy), and not otherwise specified. OligoCD has recently emerged as an intermediate form between UCD and MCD, with unclear clinical behavior, and IPL has not been validated in a Western cohort. We retrospectively analyzed 217 patients with CD evaluated at our institution between January 2004 and August 2024. Survival probabilities were compared using log-rank tests. Overall, 57% had UCD, 20% had oligoCD, and 23% had iMCD. Patients with oligoCD and iMCD more frequently exhibited systemic symptoms than those with UCD. Patients with oligoCD and iMCD had significantly shorter event-free survival (EFS) of 8.9 and 2.3 years, respectively, than those with UCD (not reached; P< .001 and P< .02). Among iMCD subtypes, iMCD-IPL demonstrated a longer EFS than iMCD-TAFRO (P = .02), with no deaths during the follow-up periods. The results validate oligoCD and iMCD-IPL as new subtypes in this Western cohort. The survival outcome in oligoCD was intermediate between UCD and iMCD, with only a subset of patients with oligoCD requiring systemic therapy. iMCD-IPL had a favorable survival outcome in this US cohort, similar to what has been reported in non-Western countries. Tailoring treatment strategies to disease subtypes and vigilant monitoring of oligoCD for progression may improve survival outcomes in CD.

PURPOSE Outcomes in systemic light chain (AL) amyloidosis have improved with modern therapy limiting utility of existing risk stratification models. We validate a new staging system, incorporating longitudinal strain (LS) to the biomarker-based (NT-proBNP and Troponin-T) staging system in the contemporary treatment era (2015-2024). METHODS AL International Staging System (AL-ISS) was derived from a cohort of patients with AL amyloidosis from the UK National Amyloidosis Centre (2015-2019). The model was validated in patient cohorts from Europe (Greece, Italy, the Netherlands, and Switzerland), the United States (2015-2024), and the United Kingdom (2020-2024). RESULTS In total, 2,493 patients were included (derivation, n = 573; validation n = 1,920). In a multivariable model for the derivation cohort, LS ≥ –9% and cardiac biomarkers at previously validated thresholds (NT-proBNP 332 ng/L and 8,500 ng/L and high-sensitivity troponin T ≥ 50 ng/L) were independent poor prognostic factors stratifying patients into stages I, II, IIIA, IIIB, and IIIC. In the validation cohort, the patient stages were stage I: 317 (17%), II: 782 (41%), IIIA: 551 (29%), IIIB: 174 (9%), and IIIC: 96 (5%), respectively (first-line daratumumab treated: 826; 43%). With a median follow-up of 34 months, median overall survival (OS) was not reached (NR); estimated 1-year, 2-year, and 3-year OS was 82%, 74%, and 70% respectively. The median survival for stages I to II, IIIA, IIIB, and IIIC were NR, 67, 26, and 7 months (1-year OS IIIC 53% v 68% for IIIB in the daratumumab-treated patients), respectively ( P < .001). External validation exhibited good predictive performance: 12-month calibration slope was 1.09, Harrell C 0.69, Royston D 1.19, and R 2 D 0.25. Stage IIIC independently discriminated the poorest outcome across all cohorts. CONCLUSION This defines and validates a new staging system from systemic AL amyloidosis with robust identification of an ultra-poor risk stage (IIIC) in contemporarily treated patients.

ABSTRACT Light chain multiple myeloma (LCMM) is a subtype of multiple myeloma (MM) characterized by the exclusive production of immunoglobulin light chains and accounts for 15%–20% of newly diagnosed MM. A comprehensive comparison of LCMM with MM producing intact immunoglobulin (non‐LCMM) remains limited. In this retrospective study, we described distinct clinical and cytogenetic features and assessed long‐term outcomes in 852 LCMM patients diagnosed between 01/01/2004 and 12/31/2022, compared with non‐LCMM controls matched for age, sex, and year of diagnosis. On univariable analysis, LCMM patients were more likely to present with elevated creatinine (> 2 mg/dL), beta‐2‐microglobulin ≥ 5.5 mg/L, elevated LDH, hypercalcemia, t(11;14), del(13q), and t(6;14). Conversely, IMS‐IMWG high‐risk disease, hyperdiploidy, t(4;14), and serum albumin < 3.5 g/dL were less common. On multivariable analysis, elevated creatinine (OR: 5.1, 95% CI: 1.2–27, p = 0.04), t(11;14) (OR: 2.6, 95% CI: 1.3–5.2, p = 0.006), and del(13q) (OR: 4.1, 95% CI: 2.1–8.2, p < 0.001) were independently associated with LCMM, while IMS‐IMWG high‐risk disease (OR: 0.3, 95% CI: 0.1–0.8, p = 0.02) and hyperdiploidy (OR: 0.3, 95% CI: 0.1–0.7, p = 0.002) were less frequent. Despite these differences, progression‐free survival with frontline treatment (HR: 0.97, 95% CI: 0.84–1.11, p = 0.63) and overall survival (HR: 0.99, 95% CI: 0.87–1.13, p = 0.94) were similar between LCMM and non‐LCMM patients. This study highlights the distinct clinical and cytogenetic features of LCMM, marked by higher rates of renal failure, t(11;14), and del(13q), lower prevalence of IMS‐IMWG high‐risk disease, and comparable survival outcomes.

ABSTRACTIntroductionRituximab is used off‐label for treating cold agglutinin disease (CAD) in the United States; however, real‐world data on its use are limited.MethodsThis study examined (1) treatment patterns, (2) prespecified safety outcomes, and (3) changes in hemolytic markers post rituximab infusion (threshold change from baseline: hemoglobin [Hb]: ≥2 g/dL increase; bilirubin or lactate dehydrogenase [LDH]: ≥50% decrease). Of 611 patients with CAD (Cohort 1) identified using Optum's de‐identified Market Clarity database (2007‐2021), 94 who received rituximab (Cohort 2) were included.ResultsRituximab was predominantly used as monotherapy; the median (interquartile range; IQR) number of rituximab courses per patient was 1.0 (1.0–2.0); 24 (25.5%) patients had ≥1 incomplete course and 37 (39.4%) required blood transfusion. The incidence rate (IR) of serious infections per 1000 patient‐years (95% CI) post rituximab initiation was three times higher than before rituximab initiation (637.1 [242.2–1032.0] vs. 245.4 [125.1–365.6]). Cohort 2 had a similar IR of thromboembolic events and slightly higher hospitalization rates and deaths than Cohort 1. After the first course of rituximab, 69.5% (41/59), 59.6% (28/47), and 31.3% (10/32) of patients reached thresholds for Hb, bilirubin, and LDH, respectively. The median (IQR) duration of improvement was 44 (13.3–90.8), 98 (29.0–257.0), and 93 (21.3–161.8) days for Hb, bilirubin, and LDH, respectively. Reversal from threshold occurred in 68.3% (28/41), 53.6% (15/28), and 80.0% (8/10) of patients for Hb, bilirubin, and LDH, respectively.ConclusionRituximab showed a limited durability of response and an increased risk of infection, suggesting the need for more effective and safer treatment options.Trial Registration: The authors have confirmed clinical trial registration is not needed for this submission.