Citations 605

Outcomes of Venetoclax-Based Treatment Combinations in Relapsed/Refractory Multiple Myeloma: Real-World Practice Patterns and Impact of Cytogenetics on Outcomes

Blood | December 6, 2024 | Volume: 144 | Issue: Supplement 1 | Pages: 4728-4728

10.1182/blood-2024-208736

Background: Venetoclax (Ven), a BCL2 inhibitor, has shown promising responses in multiple myeloma (MM) patients with t(11;14) and/or BCL2 expression. However, consistent benefit in clinical trials remain elusive. This report evaluates the efficacy and safety of Ven combination therapies, including in the non-t(11;14) subgroup, and examines the impact of secondary cytogenetic abnormalities (SGA) on outcomes. Methods: This retrospective study included multiple myeloma (MM) patients without concurrent AL amyloidosis treated with Ven-based combinations at Mayo Clinic sites from January 2015 to December 2023. FISH data was collected at diagnosis and before venetoclax initiation to assess SGAs. Refractoriness was defined by progression on or within 60 days of stopping treatment. Patients refractory to at least one proteasome inhibitor (PI), immunomodulatory drug (ImiD), and anti-CD38 antibody were considered triple-class refractory (TCR). Ven combinations were grouped as: Daratumumab/CD38 antibody (Dara)-Ven based if received Dara ± other drugs, PI-Ven-based without Dara, Ven-dexamethasone (Ven-d), and other combinations (Ven-Misc). BCL2 expression in patients without t(11;14) was determined by immunohistochemistry (IHC). Progression-free survival (PFS) was calculated from treatment initiation to disease progression or last follow-up. Results: We included 232 patients in this study. The median age at diagnosis of MM was 62 years (range 32-87), and the median age at initiation was 68 years (range 35-89). The median time from diagnosis of MM to initiation of Ven was 55 months (95% CI 28, 89 months), and the median follow-up from initiation of Ven-based treatment was 17.2 months (95% CI: 14, 22). Patients had received a median of 3 lines (IQR 4-6); 65% (n=152) of patients were TCR, 71% (n=163) had received autologous stem cell transplant and 7% (n=16) patients had received prior immune effector therapy prior to initiation of Ven-based therapy. The majority (83%, n=190) of the patients harbored a t(11;14); in the patients without t(11;14), a BCL2 expression by IHC was tested in 18 patients and positive in 17 patients. The most common Ven-based combinations included: Dara-Ven-d (19%, n=44), PI-Ven-d (30.2%, n=70), Ven-d (48.3%, n=112), Ven-misc (2.6%, n=6). The overall response rate for the entire cohort was 57% [64% for t(11;14) and 26% for non t(11;14), p<0.0001]. The median PFS for the entire cohort was 9.5 months (95% CI 8.5,13), and the duration of response was 18 months (95% CI 15.2-23.3). The median PFS was 11.8 months (95% CI 9.5-16.7) for patients harboring a t(11;14) compared to 2.9 months (95% CI 1.8, 8.4) for patients without a t(11;14), p<0.0001. Among the non-t(11;14) cohort with BCL2 expression, the median PFS was 1.8 months (95% CI: 1.2-4.2). Among the 190 patients with t(11;14), 18% (34/190) harbored deletion 17p and 32% (60/193) harbored a 1q gain/amplification (referred hereforth as 1q21+) at initiation of Ven-based therapy. In the cohort of patients with t(11;14), the presence of either del17p or 1q21+ (n=85/190) was associated with a significantly inferior PFS [median PFS 8.2 months (95% CI: 5.5,13)] vs. 15.1 months (95% CI: 11.6, 22), p=0.03. At the last follow-up,42 patients had ongoing treatment with ven-based combination. Most common reasons for discontinuation were progression (77% N=140), adverse effect (12%, n=22), patient/provider preference(9%, n=17); 2% (n=4) patients died without progression (3 infection, 1 unclear). The most commonly utilized maximum dose of venetoclax was 400 mg (42%); 15% (n=35) of patients required a dose reduction, and 23% (n=54) received a ramp-up. Tumor lysis syndrome was not noted in any patient. Infectious complications were noted in 23% (n=52). The estimated median OS from initiation of ven-based Rx was 34 months (95%CI 25-47). The estimated median OS for patients without a t(11;14) was 6.2 months (95% CI: 3.3-11.3) compared to 46 months (31.4-54.1), p<0.0001. In the t(11;14) subgroup, the 18-month OS rate was 79% for patients without 1q21+/del17p vs. 50% for patients with a 1q21+/del17p (p=0.002). Conclusion: Venetoclax-based regimens represent an important treatment option for patients harboring a t(11;14). The PFS in patients with BCL2 expression without t(11;14) was poor suggesting lack of efficacy of venetoclax-based regimens for that subgroup. Presence of concurrent del17p and/or 1q21+ with t(11;14) portends an inferior PFS.
Outpatient Management of Bispecific Related Toxicities: An Observational Study of Safety Outcomes and Resource Utilization

Blood | December 6, 2024 | Volume: 144 | Issue: Supplement 1 | Pages: 5047-5047

10.1182/blood-2024-199229

Cytokine release syndrome (CRS) commonly occurs during initiation of bispecific T-cell engaging therapy (BsAbs) for multiple myeloma (MM) (NEJM 2022;387:495, NEJM 2022;387:2232, Nat Med 2023;29:2259). Pre-medications, step-up dosing (SUD), and monitoring minimize high-grade toxicity risk, while protocolized outpatient (OP) management of BsAbs and toxicities could reduce resource utilization and improve patient satisfaction. At Mayo Clinic, SUD, clinical assessment and grade 1 CRS management occurs primarily as an OP for patients with MM receiving BsAbs. This study aims to assess the current OP management practices of BsAbs and related toxicities including patient outcomes, admission rates, and resource utilization. Patients with MM who received SUD from August 23, 2023, to March 29, 2024, were included. Baseline demographics, patient outcomes, and CRS management details are summarized. Resource utilization outcomes included level of care, length of hospital stay (LOS), and high-cost drug administration. 38 patients received MM BsAbs during the study timeframe. 34 patients initiated OP SUD (teclistamab n=17 and talquetamab n= 17). The median age was 71 years, 59% were male, 82% were white, and 88% had Medicare coverage. Median number of prior lines of therapy was 6. There were 317 OP encounters with a median of 10 encounters per patient. Of these, 72% were planned in-person assessments, 5% were unplanned clinic visits for potential toxicity-related symptom assessment, and 20% were phone visits that obviated in-person assessment. 66 of 68 doses of talquetamab (total of 1,628 mg) and 48 of 50 doses of teclistamab (total of 2,048 mg) were administered and billed in the OP setting. 24 patients (71%) that initiated OP SUD developed CRS (grade 1 n=16, grade 2 n=7). Management of the initial CRS event included steroids and acetaminophen, with or without tocilizumab. 2,600 mg of tocilizumab administered in the OP setting. Recurrent CRS was seen in 5 patients and also treated entirely OP. 4 patients developed ICANS (grade 1 n=3, grade 3 n=1). Hospitalization following OP SUD initiation occurred in 18 (53%) patients at some point during treatment. Indications included grade 2 CRS (n=6), ICANS (grade 1 n=3), refractory CRS (n=7), infection (n=1), GI bleed (n=1), planned observation for comorbidities or prior CRS (n=2), loss of caregiver (n=1), atrial fibrillation (n=1), heart failure (n=1), and pain crisis (n=1). Median LOS was 2 days. Recurrent admission occurred in 41% and median LOS was also 2 days for subsequent admissions. Two patients were admitted to the intensive care unit for hypotension or arrhythmia. 1 patient required dialysis. In total for SUD during the study time frame, 51 mg of teclistamab, 176 mg of talquetamab, and 8,240 mg of tocilizumab were billed under an IP encounter, which likely was due to inpatient administration or hospital admission within 72 hours of receiving the OP SUD. This descriptive study of our OP BsAb management practice demonstrated that 47% of patients remained OP, even with a CRS event. The CRS rate did not surpass those in landmark clinical trials and aligns with real-world data previously reported (Blood Cancer J 2024;14:35.). Availability and use of patient monitoring capabilities along with lack of sentinel outcomes emphasizes the safety of an OP BsAb practice. Drivers of financial burdens and savings include location and reimbursement of high-cost drugs and admission rates. Median LOS was less than half of what's anticipated with inpatient SUD. Inpatient administration of high-cost drugs can be more costly compared to OP due to associated medical costs and insufficient reimbursement in a population primarily insured by Medicare which reimburses inpatient mediations based on the Diagnostic Related Group (DRG) unless the medication has New Technology Add on Payment (NTAP). Using expected Medicare reimbursement rates and wholesale acquisition costs while excluding variable DRG reimbursement and NTAP impacts for teclistamab, the total net revenue improvement for shifting use of all teclistamab, talquetamab, and tocilizumab OP is $115,004 for the period analyzed (CMS.gov 2024). In conclusion, OP management of patients undergoing SUD for MM BsAbs is safe and has substantial reductions in resource utilization and costs.
Characteristics and Outcomes of Patients with Second Hematological Malignancies after Autologous Hematopoietic Cell Transplantation for Multiple Myeloma

Blood | December 6, 2024 | Volume: 144 | Issue: Supplement 1 | Pages: 5149-5149

10.1182/blood-2024-210932

Background: There is an increased risk of second primary malignancies including second hematological malignancies (SHM) in multiple myeloma (MM) patients undergoing autologous stem cell transplant (auto-SCT) followed by lenalidomide maintenance. We analyzed the characteristics and outcomes of patients who developed SHM after an auto- SCT for MM. Methods: A retrospective study of all MM patients who underwent auto- SCT at Mayo Clinic, Rochester between January 1, 1990, and 31 August 2023 and later developed SHM. Demographic, clinical and pathologic data were collected retrospectively. Overall survival (OS) was calculated from the date of auto-SCT to the date of last follow up. Statistical analyses were performed using GraphPad prism 9.0. Chi-square test was used to calculate the difference between categorical variables. Kaplan Meier method and log rank test were used to estimate OS. Results: Among 3513 patients who underwent at least 1 auto-SCT, 104 (2.9%) developed a SHM at a median follow up of 59 (range, 0.2-265) months. Patients who developed SHM, more frequently received pretransplant alkylating agents (37.5 vs 24.2 %, odds ratio [OR], 1.87; P=0.003) and topoisomerase II inhibitors (anthracyclines/etoposide) (17.3% vs 10.4%, OR [1.79]; P=0.03) compared to a control group of MM patients without SHM. Further, exposure to lenalidomide (77.8% vs 57.6%, OR[2.59]; P <0.0001) and radiation therapy (32.6% vs 23.1%, [1.54]; P=0.04) were more often seen in the SHM cohort compared to control group. Among the 381 patients who underwent > 1 auto- SCT, 3.1% developed SHM. Therapy related myeloid neoplasms (t-MN) accounted for 90.3% of cases [n=94; t-myelodysplastic syndrome (t-MDS=64), t-acute myeloid leukemia (t-AML=12), t-MDS transformed to AML(n=16), chronic myeloid leukemia (n=1), MDS/myeloproliferative neoplasm overlap syndrome (n=1)]. Eight patients (7.6%) developed therapy related B- cell acute lymphoblastic leukemia (t-ALL); Philadelphia (Ph) negative ALL (n=7) and Ph- like ALL (n=1). One patient each developed mixed phenotype acute leukemia and acute leukemia, not otherwise specified. Sixty patients (57.6%) were males and the median age at diagnosis of SHM was 70 (range, 43-84) years. The median time from auto-SCT to diagnosis of SHM was 58.5 (range, 7-236) months. In a multivariate analysis, receiving an alkylating agent (hazard ratio [95% confidence interval]: 2.51 [1.54 to 4.01]; P = 0.0002) and/or topoisomerase II inhibitor as induction for MM (3.12 [1.59 to 5.88]; P = 0.0006), exposure to lenalidomide (7.08 [3.92 to 13.50]; P = <0.0001) and radiation therapy (1.60 [1.02 to 2.44]; P = 0.03) were independent predictors of developing SHM. At diagnosis, 57% (n=37) of t-MDS and 71% (n=20) with t-AML had high risk disease per R-IPSS and 2022 European Leukemia Net respectively. Clonal abnormality in chromosome 5 and/or 7 was present in 45% (n=42) of patients. Complex and monosomal karyotype was seen in 32% (n=30) with t-MN. The most frequently mutated genes based on next generation sequencing data included TP53 (n=33), DNMT3A (n=9), RUNX1 (n=5), TET2 (n=4) and CEBPA (n=4). In the t-MDS/AML cohort, 3 patients (3.1%) underwent second auto-SCT and 9 (9.5%) received allogenic SCT (allo-SCT) for SHM. After a median follow-up of 27.2 months, the median OS from t-MDS/AML diagnosis was 8.04 months (95%CI, 6.1-11.0 months) and there was no difference in median OS for allo-SCT recipients versus nonrecipients (9.1 vs 6.8 months, P =0.19). In the t-ALL (n=8) cohort, all of them received lenalidomide based induction and five received lenalidomide maintenance. Most of the t-ALL patients had adverse risk cytogenetics [IKZF1 deletion (n=2), complex karyotype (n=2), TP53 mutation (n=1) and P2RY8-CRLF2 fusion (n=1)]. Three patients with t-ALL underwent allo-SCT and the median OS for allo-SCT recipients versus non recipients were 8.3 vs 7.9 months respectively, P=0.50. Among patients with SHM, 92.3% (n = 96) have died with SHM (72%) being the most common cause of death. MM patients who developed SHM had an inferior OS when compared to those without SHM (median OS, 75 vs 90 months, P =0.006). Conclusion: SHM following auto-SCT tends to have aggressive disease biology with poor outcomes. Short term follow up underestimates the risk of SHM and the higher incidence noted in our study may be due to longer follow up. As the OS in MM patients continues to improve, SHM remains an important challenge in improving long term outcomes.
Real-World Clinical Outcomes in Patients Initiating Covalent Btki (cBTKi) with and without Incident Cardiovascular Adverse Events By Line of Therapy for Chronic Lymphocytic Leukemia (CLL) and Small Lymphocytic Lymphoma (SLL)

Blood | December 6, 2024 | Volume: 144 | Issue: Supplement 1 | Pages: 3722-3722

10.1182/blood-2024-198469

Background: CLL is one of the most common types of leukemia in the United States, with an estimated 20,700 new cases in 2024. Although cBTKis have become the standard of care for CLL/SLL in treatment-naïve and relapsed/refractory patients, cardiovascular (CV) toxicity is a known side effect. Further, clinical outcomes often worsen as patients progress beyond 1st-line therapy (1L), and the frequency of CV adverse events (CVAEs) may increase with age and as patients progress to 2nd-line or later therapies (2L+). This research evaluated the real-world incidence of CVAEs and clinical outcomes in patients who initiated cBTKi between 2020 and 2023. Methods: Adult patients diagnosed with CLL/SLL who initiated cBTKi treatment (index date) between 2020-2023 in the United States were identified using claims data from Optum's de-identified Clinformatics® Data Mart Database and followed up to 36 months post-index. Cohorts were assessed as those initiating 1L or 2L+, reflecting treatment-naïve and relapsed/refractory patients. Results were presented for patients with an incident CVAE (not present pre-index) and those without. Demographics, incident CVAEs, overall survival (OS) and proportion of patients who discontinued index cBTKi therapy, initiated next treatment or experienced death (NT+D) were assessed. Time to CV event (TTCE) for ibrutinib and acalabrutinib were determined using a Kaplan-Meier (KM) model and Log rank test. Results: Overall, 2,163 eligible patients were identified with a mean ± SD age of 73.8 ± 9.2 years, and 40.6% were female. Of these, 1,958 (90.5%) were included in the 1L cohort and 205 (9.5%) in the 2L+ cohort; 619 (31.6%) and 63 (30.7%) patients had CVAEs, respectively. The mean ± SD [median] observation period was 1.6 ± 0.9 [2.0] years in 1L and 1.5 ± 1.0 [1.0] years in 2L+. The most common cBTKi (in 1L and 2L+) at index were ibrutinib (55.5% and 55.6%), followed by acalabrutinib (40.3% and 38.5%), and zanubrutinib (4.1% and 5.9%). At 12-months post-index, the proportion of 1L patients with and without CVAEs who discontinued treatment was 44.9% and 41.6%, rising to 65.6% and 59.0% by 36-months post-index, respectively. For those in 2L+, 50.8% and 40.8% of those with and without CVAEs discontinued treatment by 12-months; 68.3% and 55.6% discontinued by 36-months. Among those with and without CVAEs, NT+D in 1L patients was 35.9% and 22.5% within 12-months post-index and 56.9% and 32.8% by 36-months. In the 2L+ cohort, 46.0% and 31.7% experienced NT+D by 12-months, rising to 63.5% and 41.5% by 36-months. OS in 1L patients was 84.7% and 93.1% in those with and without CVAEs at 12-months and 69.1% and 88.0% at 36-months. For 2L+ patients, OS was 71.4% and 88.0% at 12-months and decreased to 54.0% and 80.3% at 36-months, among those with and without CVAEs, respectively. The most common incident CVAEs following cBTKi initiation in the 1L and 2L+ cohorts were hypertension (31.2% and 21.7%), heart failure (14.6% and 17.7%), atrial fibrillation (13.9% and 18.4%), atrial flutter (13.3% and 16.9%), and ventricular arrythmias (13.0% and 14.5%). The occurrence of incident CVAEs between 1L patients who received acalabrutinib and ibrutinib was 3.4% and 13.2% for atrial fibrillation, 2.7% and 12.7% for atrial flutter, 9.3% and 31.0% for hypertension, and 6.8% and 11.7% for ventricular arrythmias. For 2L+, the proportion experiencing CVAEs with index acalabrutinib or ibrutinib were 8.6% and 14.8% for atrial fibrillation, 7.6% and 14.8% for atrial flutter, 10.5% and 25.0% for hypertension, and 10.1% and 8.8% for ventricular arrythmias. Among acalabrutinib and ibrutinib patients, KM estimates (medians not reached) in 1L showed that 84% and 72% of patients would not experience a CVAE by 12 months, with 57% and 52% not experiencing a CVAE at 36-months (p<0.001); 2L+ KM estimate rates were 77% and 73% at 12-months and 64% and 60% at 36-months (p=0.28). Mean TTCE for acalabrutinib and ibrutinib in 1L was 2.2 and 1.9 years with 1.6 and 1.2 years in 2L+. Summary/Conclusion: Utilizing real-world evidence from patients with CLL/SLL receiving cBTKIs, this study highlights the CV disease burden among patients who incur new CV events in 1L or later lines of therapy. This research underscores the need for innovative therapies with improved efficacy and CV safety profiles that delay progression to later lines of therapy, as well as careful CV monitoring to allow for early management and improved outcomes.
Predictors of Liver Response in Light Chain (AL) Amyloidosis: A Study with 130 Patients

Blood | December 6, 2024 | Volume: 144 | Issue: Supplement 1 | Pages: 3308-3308

10.1182/blood-2024-202059

Introduction: Light chain (AL) amyloidosis is a clonal plasma cell disorder characterized by tissue deposition of misfolded immunoglobulin light chains in the form of amyloid, leading to organ dysfunction. Halting the production of the amyloidogenic free light chains by achieving a deep hematologic response (HemR) is key to improving organ function, however, variation in organ responses exists. In this work, we investigated variables associated with liver response (LivR) in a large cohort of patients with AL amyloidosis. Methods: Retrospective study of newly diagnosed AL amyloidosis patients with liver involvement seen at Mayo Clinic within 90 days of diagnosis between January 2000 and December 2021. Patients were eligible if they (1) had liver involvement, defined as a baseline alkaline phosphatase (ALP) ≥ 1.5 x upper limit of normal (ULN) and (2) had LivR measurements at least twice annually in the first year from treatment and annually afterward. LivR was defined as a >50% reduction in alkaline phosphatase (ALP) from baseline value or normalization of ALP. LivR was recorded at 6, 12, and 24 months from treatment initiation and at the best LivR achieved. Patients who died prior to landmark assessment were considered non-responders at subsequent milestone assessments. Covariates associated with LivR were identified by univariate and multivariable logistic regression analyses and a proportional subdistribution hazard (Fine-Gray) model for competing risk (treating death as a competing event). Multivariable logistic regression models for LivR were created using best subset selection, with calculation of odds ratio (OR) and 95% confidence interval (CI). Results: A total of 130 patients were included, with a median age of 60 years (IQR 53-66), male predominance (69%), and a median follow-up of 8.8 years. Sixty percent of patients had lambda isotype, the median ALP was 368 IU/mL (IQR 279-589), with 48% of patients having ALP ≥3 fold the upper limit of normal (ULN). Median bilirubin was 0.7 mg/dL (IQR 0.5-1.1). Forty-three percent of patients received front-line autologous stem cell transplant (ASCT) with or without prior induction therapy, and 5% received daratumumab-based therapy as their front-line treatment. Liver response rate increased with time, with 36 patients (28%) achieving a LivR at 6 months, 47 (36%) at 12 months, 63 (48%) at 24 months, and 94 (72%) at best response. The median time to liver response was 14 months (7.22-32.67). At the 24-month landmark, age <60 years, ALP ≥3 fold ULN, and front-line ASCT were significantly associated with achieving a LivR on univariate logistic regression. On univariate logistic regression at best liver response, age <60 years, ALP ≥3 fold the ULN, kappa isotype, ≥HemVGPR within 6 months, and front-line ASCT were significantly associated with obtaining a LivR. On multivariable logistic regression, at 24 months, ALP ≥3 folds of ULN (OR=2.9, 95% CI 1.4-6.3, P=0.004) was significantly associated with an increased likelihood of LivR. Achieving ≥HemVGPR and front-line ASCT were also associated with increased LivR likelihood, although not statistically significant (p=0.094, p=0.078, respectively). At best liver response, achieving ≥HemVGPR within 6 months (OR=5.2, 95% CI 1.9-14.8), kappa isotype (OR=3.2, 95% CI 1.1-10.0), ALP ≥3 folds of ULN (OR=3.3, 95% CI 1.3-9.9), and front-line ASCT (OR=5.3, 95% CI 1.9-16.7) were factors significantly associated with LivR. The Fine-Gray model demonstrated kappa isotype (HR=1.7), baseline ALP ≥3 folds of ULN (HR=2.1), ≥HemVGPR within 6 months (HR=1.9), and age <60 years at diagnosis (HR=1.9) to be positively associated with achieving LivR (P<0.05). Conclusions: In this large cohort of liver AL amyloidosis, LivR was achieved in 72% of patients, and amongst responders, the median time to response was 14 months from therapy initiation. Predictors of LivR included kappa isotype, deep hematological response in the first 6 months of initial therapy, ASCT usage, and higher baseline ALP levels. These findings better inform clinicians on the likelihood of achievement of liver response and may enable ways to improve its achievement.
Healthcare Resource Utilization and Costs in Patients with Chronic Lymphocytic Leukemia (CLL) or Small Lymphocytic Lymphoma (SLL) Treated with Covalent Btki (cBTKi): Real-World Impact of Cardiovascular Adverse Events

Blood | December 6, 2024 | Volume: 144 | Issue: Supplement 1 | Pages: 3738-3738

10.1182/blood-2024-200345

Background: Although Covalent BTKis have revolutionized treatment of CLL/SLL, cardiotoxicity is a known side effect, which can increase the total costs to the healthcare system. This study evaluated the real-world healthcare resource utilization (HCRU) and costs in patients who did and did not experience incident cardiovascular adverse events (CVAEs) during cBTKi treatment. Methods: Adult patients diagnosed with CLL/SLL who initiated ibrutinib or acalabrutinib treatment (index date) between 2020-2023 in the United States were identified using claims data from Optum's de-identified Clinformatics® Data Mart Database and followed up to 36 months post-index. Patients were stratified into two cohorts based on the presence of an incident CVAE during treatment with index cBTKi, defined as the occurrence of a CVAE not present in a patient's medical history. HCRU and costs were evaluated on a per 1,000 patient-months basis. Z tests and univariate gamma general linear models were used to compare HCRU and cost rates. HCRU between those who received ibrutinib or acalabrutinib were also assessed. Results: Overall, 2,069 eligible patients were identified with a mean ± SD age of 73.7 ± 9.1 years, and 40.4% were female. The mean ± SD [median] treatment-specific observation period was 11.4 ± 9.5 [8.5] months. Of the total cohort, 442 (21.4%) experienced at least one incident CVAE, while 1,627 patients (78.6%) experienced no CVAEs. Among those without a pre-index history of the specific CV AE of interest, the proportion of patients with incident events were 21.4% for hypertension, 9.8% for atrial fibrillation, 9.2% for atrial flutter, and 9.6% for ventricular arrhythmias. Patients who experienced an incident CVAE had 4,334 total days with medical service compared to 3,138 days in those who did not (p<0.001). The drivers of differences in total medical service days between those with and without CVAEs were inpatient days (690 vs 230), followed by outpatient days (2,798 vs 2,425), other visits (e.g., hospice; 662 vs 375), and emergency room (ER) visits (184 vs 109). Total days with medical service were 3,458 in those who received ibrutinib and 3,410 with acalabrutinib. Total healthcare cost rates in those who experienced an incident CVAE were $20,250,560 compared to $17,413,460 in those without CVAEs (p<0.001). Inpatient costs drove differences in total costs between those with CVAEs and those without ($3,417,948 vs $915,839, p<0.001), followed by outpatient ($2,415,060 vs $1,769,628, p<0.01) and ER costs ($186,820 vs $87,585, p<0.001). Pharmacy costs were the largest contributor to total cost rates for both cohorts ($14,016,900 for those with a CVAE vs $14,473,270 without any CVAEs, p<0.001). Regarding specific incident CVAEs, the cost difference in total costs between those with and without the event were $3,789,820 for atrial fibrillation (higher in those with the event), $3,867,160 for atrial flutter, $3,674,860 for ventricular arrhythmias, and $721,840 for hypertension. Inpatient costs were the largest driver in total cost differences between those with and without the specific CVAE of interest; inpatient cost differences were $3,255,699 higher in those with atrial fibrillation, $3,436,913 with atrial flutter, and $3,299,371 with ventricular arrhythmia. For hypertension, pharmacy costs drove differences in total costs and were $346,570 higher in those with the CVAE. Summary/Conclusion: Overall, the economic burden remains high in patients treated for CLL/SLL, especially in cBTKi patients experiencing an incident CVAE. These findings highlight the importance of careful treatment selection, safety monitoring, and early management of CVAEs in order to improve patient outcomes and reduce the downstream impacts on healthcare resources and costs.
First Results from the Dose Escalation Part of the Phase 1 Study of KTX1001, an Oral, First-in-Class, Potent Inhibitor of MMSET/NSD2 for Relapsed/Refractory Multiple Myeloma (RRMM)

Blood | December 6, 2024 | Volume: 144 | Issue: Supplement 1 | Pages: 3370-3370

10.1182/blood-2024-199174

Background: Despite recent major advances, multiple myeloma (MM) remains incurable using therapies that are currently available to patients. There are no available/approved targeted therapies for MM that allow for individualized therapeutic approaches to the disease. Fifteen to 20% of newly diagnosed MM patients have a translocation of chromosomes 4 and 14 [t(4;14)]. This translocation puts transcription of the gene encoding Multiple Myeloma SET domain-containing protein (MMSET or NSD2), a histone 3 lysine 36 methyltransferase, under the control of the IgH super enhancer. The super enhancer drives the overexpression of MMSET resulting in an abnormal histone code that promotes myelomagenesis. Presence of t(4;14) is associated with poor clinical prognosis (Caro Am Soc Clin Oncol Educ Book 2021). KTX-1001 is a first-in-class, selective and potent small molecule inhibitor of MMSET, and is the first investigational drug that targets the t(4;14) MM patient population. Methods: This Phase 1, first-in-human open-label study (NCT05651932) is designed to assess the safety, tolerability, and initial clinical activity of KTX-1001 in relapsed/refractory MM (RRMM) and has two parts: dose escalation (Part A) and dose expansion (Part B). In Part B, only t(4;14)+ MM patients will be evaluated in single agent and combination expansion cohorts. Patients with RRMM who have received ≥3 prior lines of therapy, including a proteasome inhibitor (PI), immunomodulatory drug (IMiD), and anti-CD38 antibody are eligible for the dose escalation part. The primary objective of the study is to determine a recommended phase 2 dose (RP2D) and schedule of KTX-1001. Secondary and exploratory objectives include pharmacokinetic (PK) and pharmacodynamic (PD) evaluation of KTX-1001, and assessment of preliminary efficacy. KTX-1001 is administered orally until disease progression, unacceptable toxicity, or patient withdrawal from the study. A Safety Review Committee (SRC) reviews all data prior to each dose escalation decision and on a regular basis. Results: As of June 14, 2024, 17 patients (pts) have been treated with KTX-1001 in Part A across 6 dose levels (SRC reviewed). Dose Level 7 has been reached with no dose limiting toxicities (DLTs). Ten of these patients are t(4;14) positive. Patients have received a median of 5 prior lines of therapy (range: 3-17), including 7 pts with prior BCMA CAR-T, 6 pts with prior BCMA bispecific and/or ADC, 5 pts with prior non-BCMA bispecific, and 12 pts with prior transplant. Patient demographics include a median age of 68 years (range: 50-83), 10 male/ 7 female, 13 white, 2 black or African American, 2 as other identified race, and 3 Hispanic or Latino pts. Six pts remain on treatment. KTX-1001 shows excellent tolerability to date, with treatment emergent AEs (TEAEs) (CTCAEv5.0) predominantly of grade 1 and 2 severity. Most frequently observed TEAEs suspected to be related to KTX-1001 include fatigue (35%), diarrhea (24%), and constipation (24%), for which no grade 3 or 4 events have been observed. Frequency and/or severity of TEAEs have not increased with escalating doses nor treatment duration, and no patients have discontinued due to an AE. Two heavily pre-treated patients [one known to be t(4;14)+] have demonstrated long-lasting stable disease and clinical benefit at 10 and 7 months respectively. Both patients have been intra-patient dose escalated. For PK and PD data collected to date, drug exposure and steady-state concentration of KTX-1001 (at C1D15, when steady state concentration has been reached) appear to be dose-proportional. PD data indicate a dose-dependent decrease in the H3K36me2 mark on treatment versus baseline across dose levels 1 through 6, suggesting that the RP2D may be reached by year end. Updated results will be presented at the congress. Conclusions: Dose escalation of KTX-1001 is ongoing with an excellent tolerability profile to date and demonstration of on-target pharmacodynamics that will inform the determination of the RP2D(s). These PD data support the targeted mechanism of action of KTX-1001 to selectively inhibit MMSET and break the t(4;14) histone code. Given KTX-1001's promising safety profile, single-agent and combination expansion cohorts with standard-of-care MM agents/classes will begin in 2025 to further optimize doses and provide proof of concept in Part B of the Phase 1 study.
Correlation between Pre-Apheresis Biomarkers and Development of Severe Cytopenias and Therapy-Related Myeloid Neoplasms in Non-Hodgkin Lymphoma Patients Undergoing Chimeric Antigen Receptor T-Cell Therapy

Blood | December 6, 2024 | Volume: 144 | Issue: Supplement 1 | Pages: 2372-2372

10.1182/blood-2024-210474

Background: Chimeric antigen receptor T-cell (CAR-T) therapy has shown substantial promise in treatment of hematological malignancies, including non-Hodgkin Lymphoma (NHL). A subset of patients develop prolonged cytopenia, comprising quality of life, increasing healthcare utilization, and imparting considerable morbidity and mortality. Therapy-related myeloid neoplasms (t-MN), typically seen in patients who receive DNA-damaging agents such as radiotherapy and alkylators, have also been observed in CAR-T recipients. CAR-Hematotox score predicts the development of hematotoxicity in CAR-T recipients using laboratory parameters obtained at lymphodepleting (LD) chemotherapy, a timepoint when the patient has already gone through leukapheresis thus committed to the CAR-T process. Therefore, it is critical to identify patients at the highest risk of prolonged cytopenia and/or t-MN prior to apheresis, making it possible for a better triage of those who will proceed with CAR-T and those who might benefit from other strategies. Methods: A retrospective analysis was conducted in NHL patients who received commercial CAR-T products between January 2018 and March 2024 at Mayo Clinic Rochester, Arizona and Florida. Clinical and laboratory data including age, hemoglobin (Hb), absolute neutrophil count (ANC), platelet (PLT), ferritin, and LDH, obtained at the initial CAR-T evaluation, typically within 1 week of leukapheresis, were used for analysis. Prior lines of therapies including autologous stem cell transplant (ASCT) were collected. Prolonged cytopenias were defined as Hb < 8 g/dL, ANC < 0.5 x 109/L, and/or PLT < 50 x 109/L at 3 months after CAR-T. t-MN was diagnosed per WHO 2016. For prolonged cytopenia, the optimal cutoff points for continuous variables were determined by maximizing the sum of sensitivity and specificity. Logistic regression was then used to determine the factors associated with cytopenia at 3 months post-CAR-T. For t-MN, maximally selected log-rank statistics was used to determine the optimal cutoffs. We used competing risk analysis to determine the factors associated with development of t-MN. Death without t-MN was considered a competing risk. For both analyses, the factors with P < 0.1 in univariate analysis (UVA) were included in multivariate analysis (MVA). Results: Among the 387 NHL patients, with a median follow-up of 11 months (95% CI 8.7 - 12.2 months), 56 (14.4%) developed (41, 10.5% with 1 cytopenia; 14, 3.6% with 2 and 1, 0.2% with cytopenia in all 3 lineages), 20 (5.2%) developed and 315 (81.2%) did not have either. Factors associated with prolonged cytopenia: were age >, PLT ≤ 150, ferritin ≥ 600, and LDH ≥ 250. Univariate analysis identified baseline Hb, ANC, PLT and ferritin to be significantly associated with prolonged cytopenia. MVA identified Hb ≤ 11 (HR = 1.98; 95% CI 1.03-3.85, P = 0.042) and PLT ≤ (HR = 2.56; 95% CI 1.39-4.78; P = 0.003) to be associated with the development of prolonged cytopenia. Factors associated with t-MN:were age > 65 years, Hb ≤ 9 g/dl, ANC < 3.8, PLT ≤ 80, Univariate analysis identified age, Hb, ANC, PLT, ferritin, and ≥ 3 prior lines of treatment to be significantly associated with t-MN. On MVA, age ≥ 65 (HR = 3.91; 95% CI 1.52-10.03; P = 0.004), Hb ≤ 9 (HR = 3.49; 95% CI 1.38-8.85; P = 0.008), ferritin ≥ 300 (HR = 3.06 ; 95% CI 1.08-8.67; P = 0.035) and ≥ 3 prior lines of therapy (HR = 3.25; 95% CI 1.33-7.94 ; P = 0.010) were associated with t-MN development. Association of prolonged cytopenia with t-MN development: Prolonged cytopenia was noted in 45% of patients who developed t-MN and 15% of those who did not (P = 0.002). Cumulative incidence of t-MN at 1 year was 3.3% and the presence of prolonged cytopenia was associated with a higher 1of t-MN (HR 8.93, 95% CI 2.15 - 37.1, P = 0.003). Conclusions: Readily accessible clinical and lab data such as blood count and inflammatory markers at the time of CAR-T evaluation were associated with the development of prolonged cytopenias. Similarly, advanced age, anemia, high ferritin levels and history of ≥3 lines of therapy were associated with the development of t-MN. These findings, when validated in larger dataset, can be used for patient counseling and therapy selection by identifying patients at high-risk of developing hematotoxicity and/or t-MN development.
Improved Survival with Daratumumab-Cybord Compared to Cybord As Frontline Therapy in Immunoglobulin Light Chain (AL) Amyloidosis

Blood | December 6, 2024 | Volume: 144 | Issue: Supplement 1 | Pages: 2400-2400

10.1182/blood-2024-209102

Background: AL amyloidosis is a potentially fatal plasma cell dyscrasia. In a randomized phase 3 study (Kastritis E et al, NEJM 2021;385:46-58), the addition of daratumumab to cyclophosphamide, bortezomib and dexamethasone (Dara-CyBorD) significantly improved hematological and organ responses, and prolonged event-free survival (EFS). There was no overall survival (OS) difference at a median follow-up of 11.4 months. Methods: A retrospective study of AL amyloidosis patients seen at our institution between January 2018 and December 2022 who received upfront Dara-CyBorD or CyBorD. We excluded patients who received other forms of upfront therapy (including modifications of the above regimens, such as bortezomib-dexamethasone or daratumumab-dexamethasone). We compared the hematologic and organ responses, EFS and OS between the two treatment groups. Hematologic response was assessed at 2 and 6 months from therapy initiation, while cardiac and renal responses at 6- and 12-month landmarks. In all response evaluations, we included responses up to autologous stem cell transplantation (ASCT) if used or second-line therapy for any reason. For EFS analysis, an event was defined as death of any cause, hematological progression, end-stage cardiac or renal failure, or need for subsequent anti-plasma cell therapy in the absence of hematological progression. OS was calculated from the time of treatment initiation to death or last follow-up. Results: Among 641 newly diagnosed patients seen at our center between 2018 and 2022, 361 patients (56%) were included on intention-to-treat analysis [Dara-CyBorD =147 (41% of the cohort); CyBorD=214 (59%)]. There was no difference in the baseline characteristics between the treatment groups, including age, sex, difference between involved and uninvolved light chains, bone marrow plasma cells percentage, NT-proBNP and 24-hour proteinuria. The 2-month hematologic complete response (hemCR; 15.3% vs 4.4%, P<0.001) and very good partial response or better (≥hemVGPR; 62.2% vs 32.5%, respectively; P<0.001) were higher with Dara-CyBorD compared to CyBorD. At 6 months, the hemCR and ≥hemVGPR were again in favor of the Dara-CyBorD group compared to CyBorD (32.0% vs 13.7%, and 72.8% vs 46.7%, respectively; P≤0.002). The 6- and 12-month cardiac response rate in the Dara-CyBorD and CyBorD groups were 40.2% vs 22.6% (P=0.01) and 44.1% vs 23.2%, respectively (P=0.006). Cardiac ≥VGPR at the 6- and 12-month landmarks were statistically higher with Dara-CyBorD compared to CyBorD and increased in both arms between 6 and 12 months [20.5 % vs 9.3% (P=0.03) and 34.3 % vs 20.0% (P=0.04), respectively]. The 6-month and 12-month renal response to first-line therapy were numerically higher with Dara-CyBorD compared to CyBorD but were not statistically significant (48% vs 31.3%, P=0.10; 54.1% vs 30.1%, P=0.05). The 6 month and 12 months, renal ≥VGPR were numerically higher with Dara-CyBorD compared to CyBorD, again without statistical significance (26% vs 19.6%, P=0.63; 35.7% vs 17.2%, P=0.11, respectively). Treatment with Dara-CyBorD was significantly associated with lower 6-month mortality rate compared to CyBorD (8.8% vs 16.3%, P=0.04). With a median follow-up of 43.3 months (30 vs 59.4 months for Dara-CyBorD vs CyBorD, respectively; P<0.001), the two-year EFS was superior in the Dara-CyBorD group compared to CyBorD (69.1% vs 30.3%, hazard ratio (HR) 0.36, 95% confidence interval (CI), 0.26 to 0.48, P<0.001). The 2-year OS was also statistically higher in the Dara-CyBorD group compared to CyBorD (82.0% vs 69.6%, HR 0.53, 95% CI, 0.36 to 0.79, P=0.003). 148 patients (40.9%) proceeded to second-line therapy with a median of 5.1 months from first line therapy. To adjust for difference in follow-up time between the two treatment groups, we analyzed the second line therapy utilization at the 12-month mark which was statistically higher with CyBorD compared to Dara-CyBorD (42.9% vs 14.9%, P<0.001). Also, at 12 months, a higher proportion of patients treated with CyBorD received ASCT compared to Dara-CyBorD (24.3% vs 13.6%, P= 0.01). Conclusions: In this cohort of newly diagnosed AL amyloidosis patients in a large referral center, we confirmed higher hematological and organ response rates with Dara-CyBorD compared to CyBorD. We have also demonstrated that these higher response rates translate into a survival advantage of Dara-CyBorD over CyBorD.
Baseline Characteristics of Individuals with Paroxysmal Nocturnal Hemoglobinuria in an App-Based Home-Reported Outcomes Study to Evaluate Disease Burden

Blood | December 6, 2024 | Volume: 144 | Issue: Supplement 1 | Pages: 2327-2327

10.1182/blood-2024-211194

Background and significance: Paroxysmal nocturnal hemoglobinuria (PNH) is a rare condition caused by a somatic mutation in the PIG-A gene, leading to complement-mediated hemolysis and severe complications such as anemia and thrombosis. Patients often experience fatigue, dyspnea, and abdominal pain, impacting their daily lives and emotional well-being. This study aims to comprehensively explore the impact of PNH on health-related quality of life (HRQoL), alongside real-world treatment utilization and symptom burden patterns, especially as new treatments become available to this patient population. These results are based on interim baseline data from currently enrolled study participants, providing an initial assessment of their PNH disease experience. This analysis does not include any data collected prospectively during the data collection period. Study design and methods: This ongoing, prospective, observational study (NCT06411626) aims to enroll at least 128 US-based participants aged 18 or older with PNH, regardless of treatment usage. Participants are recruited through clinician-based referrals, patient advocacy organizations, and community-based online channels. All activities can be completed remotely using the Folia Health app, the single site for this study. This app-based study aims to comprehensively assess patient-reported symptom burden, treatment use patterns, and impacts of PNH on health and FACIT-Fatigue through self-reported home-reported outcomes (HROs). Participants will track symptoms and treatment use, including recently approved treatments (e.g., iptacopan, danicopan, crovalimab). HROs consist of participants' self-identified symptoms and personalized treatment plan that are tracked longitudinally against self-reported baselines. Semi-structured interviews and collaborative feedback sessions with PNH patients and clinicians yielded a comprehensive outcomes inventory for tracking key health outcomes specific to PNH. This inventory includes the ability to track infusion treatments and denote flare-ups in fatigue. Participants can customize their data collection to track symptoms in additional domains beyond those initially suggested (e.g., respiratory or immune). At enrollment, participants report baseline health status and select their relevant symptoms and treatments to routinely track for 6 months. Monthly in-app surveys will collect data on overall health and the FACIT- Fatigue. The Folia app allows participants to visualize symptoms trends, set treatment reminders, and generate reports for their care team. Results: Enrollment began on June 11, 2024. As of July 22, 2024, an interim data analysis was conducted on 20 participants; 65% (n=13) enrolled through online community-based channels and 35% (n=7) enrolled through clinic referrals. Participants selected 37 distinct symptoms and measurements and 26 distinct treatments to track over the 6-month period. The most common symptoms selected at baseline include fatigue (n=19), brain fog (n=17), and dark colored urine (n=15). PNH treatments selected for tracking include iptacopan (n=9), ravulizumab (n=5), eculizumab (n=4), and pegcetacoplan (n=3). The mean baseline FACIT- Fatigue score (n=18) was 35.7 and the median was 40 (IQR= 16). Further descriptive analyses stratified by primary treatment use will be conducted assessing characteristics of symptom burden, satisfaction with treatments-in-use, and self-reported impact on HRQoL. Conclusions: Initial interim baseline data of recently enrolled participants with PNH show a variable disease experience. This app-based, observational study aims to establish a new real-world data source to understand patient priorities related to symptom variability, treatment patterns and preference, and impacts of condition management on HRQoL.