Kumar, Shaji

PURPOSE Teclistamab is initiated with a step-up dosing (SUD) schedule to mitigate the risk of cytokine release syndrome (CRS) and immune effector cell–associated neurotoxicity syndrome (ICANS). Early teclistamab users commonly received SUD in a hospital setting. This study aimed to evaluate safety and health care resource utilization (HRU) in real-world patients with multiple myeloma who initiated teclistamab SUD in an outpatient setting. METHODS This was a retrospective study using Mayo Clinic's electronic medical records from October 26, 2022, to October 31, 2023. Patient characteristics were summarized for all patients treated with teclistamab and separately for patients who started SUD outpatient. SUD pattern, safety, HRU, and post-SUD dosing schedule were described in patients with complete SUD. RESULTS At data cutoff, 65 patients received ≥1 teclistamab dose, including 58 patients who initiated SUD outpatient (median age, 69.2 years; male, 63.8%; White, 89.7%). Among 57 patients who completed SUD in an outpatient setting, all received premedications on the days of teclistamab administrations per label recommendation; 18 (31.6%) developed CRS (13 grade 1, four grade 2, and one grade 4) and two developed ICANS (one each with grade 2 and 4). All CRS and ICANS resolved with supportive care and all patients continued treatment. Eighteen patients were admitted to the hospital for CRS treatment, with a median CRS-related hospital stay of 2 days per admission. Most (60%) doses during SUD required <1 hour clinic time between administration and checkout. Post-SUD, clinic time for treatment doses decreased to <30 minutes for most doses (82%). CONCLUSION Outcomes of this study support outpatient administration as a safe and feasible option for teclistamab SUD to potentially reduce HRU and improve patient experiences.

Abstract Several tools have been proposed for assessing frailty in multiple myeloma (MM), but most are based on clinical trial data sets. There are also limited data on the association between frailty and patient-reported outcomes and on the prognostic value of social determinants of health. This study evaluates the prognostic impact of frailty, based on the cumulative deficit frailty index (FI), and relationship and socioeconomic status (SES) in patients with newly diagnosed MM. This retrospective study included 515 patients with MM seen at Mayo Clinic (Rochester, MN) at diagnosis between 2005 and 2018. The FI was calculated using patient-reported data on activities of daily living and comorbidity data, with items scored as 0, 0.5, or 1, in which 1 indicated a deficit. The FI was calculated by dividing the total score by the number of nonmissing items. Frailty was defined as FI ≥0.15; 61% were nonfrail, and 39% were frail. Frailty and nonmarried/relationship status were associated with higher disease stage, decreased the likelihood of early transplantation, and independently associated with decreased survival. SES was not independently associated with survival. Frail patients reported worse scores for fatigue, pain, and quality of life. Approximately a quarter of patients had a deterioration in frailty status at 3 to 12 months, and &lt;10% had improvement. In conclusion, a cumulative deficit FI was associated with higher symptom burden and decreased survival in a real-world cohort of patients with newly diagnosed MM. Frailty status is dynamic and should be reassessed during treatment. Social support has prognostic value and should be evaluated in clinical practice.

Abstract Significant progress has been made in the treatment of multiple myeloma (MM), with the introduction of several new drugs with different mechanisms of action. The treatment of newly diagnosed MM has evolved dramatically with the development of highly effective combinations that include 1 or more of the new drugs. Despite the continuing improvement in the overall survival of patients with MM, nearly a quarter of the patients have significantly inferior survival, often driven by a combination of factors, including tumor genetics and host frailty. The focus of initial therapy remains rapid control of the disease with reversal of the symptoms and complications related to the disease with minimal toxicity and a reduction in early mortality. The selection of the specific regimen, to some extent, depends on the ability of the patient to tolerate the treatment and the underlying disease risk. It is typically guided by results of randomized clinical trials demonstrating improvements in progression-free and/or overall survival. While increasing risk calls for escalating the intensity of therapy by using quadruplet combinations that can provide the deepest possible response and the use of autologous stem cell transplant, increasing frailty calls for a reduction in the intensity and selective use of triplet or doublet regimens. The choice of subsequent consolidation treatments and maintenance approaches, including duration of treatment, also depends on these factors, particularly the underlying disease risk. The treatment approaches for newly diagnosed myeloma continue to evolve, with ongoing trials exploring bispecific antibodies as part of initial therapy and CAR T cells for consolidation.

Introduction: Myeloma response to treatment can be biochemical, pathological, or radiological, with pathological assessments being invasive. Next-generation blood flow (PBF) for assessment of circulating tumor plasma cells (CTCs) has shown promising results as a prognostic in Multiple Myeloma (MM) patients. CTC detection via PBF has a potential to serve as non-invasive method for assessing pathological burden of disease and response to treatment. Comparing CTC responses to the International Myeloma Working Group (IMWG) criteria will further help to understand PBF's utility in predicting response to therapy. Patients and Methods: The study conducted is a retrospective observational study. We included patients with MM treated at Mayo Clinic from 01/01/2011 to 12/31/2019 with CTC records available at the time of best response (BR) to frontline therapy. The CTC values were expressed as the number of plasma cell events per 150,000 Peripheral Blood Mononuclear Cells (CD38, CD138, CD19, CD45, Kappa, Lambda). The CTC levels were compared across all response(IMWG Criteria) groups at BR, and at baseline. The CTC response was expressed as % CTC decrease at BR from baseline. Time-to-event analyses utilized the Kaplan Meier method and Cox-proportional hazards models, with comparisons made using the log-rank test. Results: We identified 621 patients with CTC data at the time of BR to frontline therapy. Of these, 148 (24%) had baseline CTC data from diagnosis. The median age at diagnosis was 62.3 (27.2-83.7). The median follow-up was 66.15 months; the distribution of patients by treatment class is as follows- Alkylator: 0.8%, PI(Proteasome Inhibitor)+Cyclophosphamide: 27.4%, IMid: 12.7%, PI+IMid(Immunomodulator): 55.9%, PI+IMid+antiCD38: 3.2%; 378 patients (78.8%) underwent an autologous transplant. BR to initial therapy was sCR/stringent Complete Response (10, 1.6%), CR (230, 36.9%), VGPR/Very Good Partial Response (224, 36.1%), PR (123, 19.8%), MR/Minimal Response (12, 1.9%), SD/Stable Disease (14, 2.3%), PD/Progressive Disease (8, 1.3%). In the study, 64 patients (10.31%) had detectable CTCs at their BR. The distribution of CTCs across the different response categories was as follows: none (0%) in sCR, 3 patients (1.3%) in CR, 18 patients (8%) in VGPR, 24 patients (19.5%) in PR, 8 patients (66.7%) in MR, 6 patients (42.9%) in SD, and 5 patients (62.5%) in PD. The median CTC counts and their interquartile ranges for these categories showed significant variability: CR had a median of 46 (IQR: 28.5, 923), VGPR had 39.5 (IQR: 15.5, 111.25), PR had 47 (IQR: 22.75, 82.5), MR had 55 (IQR: 28.5, 85), SD had 96.5 (IQR: 22.25, 218.75), and PD had 317 (IQR: 57, 415). This Analysis of Variance (ANOVA) for response-wise distribution of CTC was &lt;0.01. Response was dichotomized as PR and above for sCR, CR, VGPR, PR and less than PR for MR, SD and PD. Median Overall Survival(OS) for PR and above was 127.8 months (vs less than PR 56.7 months, p=0.01). Median OS for CTC+ at BR was 56.7 months (vs 134.8 for CTC negative, p=0.01). On multivariate analysis, presence of CTC at best response (Hazards Ratio = 2.9, n=1.1-2.9), RISS staging at diagnosis (Hazards Ratio = 2.35, n=1.5-3.05), less than PR (Hazards Ratio =1.8, 1.1-2.9) were independent predictors of inferior OS. In patients with data for CTC available at both baseline and at BR to frontline therapy (n=148), 110 had CTC detectable at diagnosis. Among patients in various response categories, a complete disappearance of CTCs was observed in sCR (n=3, 75.0%), CR (n=36, 69.2%), VGPR (n=38, 64.4%), and PR (n=14, 60.9%). CTC responses greater than 90% were noted in VGPR (n=3, 5.1%), PR (n=2, 8.7%), and SD (n=2, 40.0%). No CTC response was reported in sCR (1, 25.0%), CR (16, 30.8%), VGPR (2, 3.4% and 13, 22.0%), PR (3, 13.0% and both 2, 8.7%), SD (1, 20.0% and both 2, 40.0%), MR (1, 50.0%), and PD (1, 33.3% and 1, 50.0%, respectively). The median OS for those with a CTC response was 112.4 months vs 28.2 months for no response. (p=0.01). Conclusion: The presence of CTC at best response is an independent prognostic marker for inferior OS. Depth of response to frontline therapy correspond to a high rate of clearance of CTCs. Presence of CTC at best response provides independent prognostic value beyond the depth of response. A complete clearance of CTC at best response is associated with improved OS. CTC levels have not been corrected for WBC counts and may not be applicable in all settings.

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&lt;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&lt;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&lt;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.

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.

BACKGROUND Several studies have highlighted the poor clinical outcomes observed among patients with relapsed/refractory multiple myeloma (MM), particularly those with triple-class refractory (TCR; refractory to at least one protease inhibitor [PI], one immunomodulatory drug [IMiD], and one anti-CD38 monoclonal antibody [mAb]) disease. The aim of this study was to describe the longitudinal changes in quality of life (QOL) and other patient-reported outcomes (PROs) among TCR MM patients who initiated a new line of therapy in real-world clinical practice. METHODS A prospective, multi-site observational study was conducted through the Mayo Clinic system. Patients with TCR MM initiating a new line of therapy (defined as the index date) were followed for a 12-month observation period. For patients initiating a CAR-T therapy, PRO survey assessments were conducted at apheresis, lymphodepletion chemotherapy, and every month after T-cell infusion until Month 6. All other patients received a survey assessment before index and every month thereafter until Month 6. PRO measures included the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ-C30; including the Global Health Score [GHS]), the EORTC Multiple Myeloma Questionnaire (QLQ-MY20; including the Disease Symptoms [DS] domain score), the EORTC QLQ for Chemotherapy-Induced Peripheral Neuropathy (CIPN20), the EuroQoL-5 Dimensions (EQ-5D), the Patient Global Impression of Severity (PGIS), and the Patient Global Impression of Change (PGIC). PRO surveys were supplemented with retrospective chart reviews conducted at 3 months and 12 months following the index date to obtain clinical information. Descriptive data were reported at each timepoint separately for patients who received CAR-T and non-CAR-T index therapies. The study is ongoing and this abstract reflects all patient data collected as of May 2024. RESULTS This interim analysis included 77 patients (58% male, 95% White, mean age 66 years). The median time interval between becoming TCR and the index date was 5.6 months (interquartile range [IQR]: 1.8, 18.2). Most patients had an Eastern Cooperative Oncology Group (ECOG) score of 0 or 1 (48% and 45%, respectively) and were Revised International Staging System (R-ISS) I or II (27% and 36%, respectively); 42% of patients had high-risk cytogenetics and 14% had extramedullary disease. The median (IQR) number of prior treatment lines was 4 (4, 5). Forty-two patients initiated a CAR-T therapy as their index therapy (12 and 30 treated with ide-cel and cilta-cel, respectively); the remaining 35 patients predominantly initiated a treatment regimen containing an IMiD (51%), a PI (54%), an anti-CD38 antibody (40%), or an alkylating agent (37%). Among these non-CAR-T patients, common regimens used were pomalidomide + elotuzumab + corticosteroids (26%), carfilzomib + cyclophosphamide + corticosteroids (20%), and pomalidomide + carfilzomib + corticosteroids (17%). Among CAR-T patients, QOL generally remained stable from apheresis (mean GHS and EQ-5D VAS were 62.3 and 66.4, respectively) to lymphodepletion (61.2 and 65.9) to Month 6 (64.2 and 68.9). Disease symptoms improved (mean DS domain scores at apheresis, lymphodepletion, and Month 6 were 25.7, 24.1, and 20.1, respectively) though pain, specifically, plateaued/worsened (mean pain domain scores were 24.5, 32.1, and 32.6). Based on the PGIC, 76% of patients reported being “a little better” or “much better” as early as Month 1, which stabilized over time (75% at Month 6). Among non-CAR-T patients, QOL largely remained stable (GHS and EQ-5D VAS was 62.9 and 68.4, respectively, at baseline and 64.9 and 67.7 at Month 6), though disease symptoms, including pain, improved over time (DS was 28.0 at baseline and 22.8 at Month 6; pain was 40.8 at baseline and 28.1 at Month 6). Based on the PGIC, 30.7% of patients reported being “a little better” or “much better” at Month 1, which improved to 52.7% by Month 6. CONCLUSIONS In this interim analysis of an ongoing prospective observational study, baseline values suggest a significant QOL burden among TCR patients. QOL generally remained stable for both CAR-T and non-CAR-T patients over the first several months post-therapy with some select improvements in disease symptoms. However, the patients (particularly CAR-T patients) directly reported some holistic improvement based on the PGIC as early as Month 1.

Introduction: The current definition of plasma cell leukemia (PCL) is based on peripheral blood smear (PBS) demonstrating ≥5% plasma cells. However, PCL cases are enriched in translocation t(11;14), which often has a lympho-plasmacytoid appearance. Detection and quantification of circulating tumor plasma cells (CTC) through peripheral blood flow cytometry (PBF) has emerged as a promising approach for assessing disease burden and prognosis in multiple myeloma (MM) patients. While PBF is more sensitive, the potential threshold values on PBF that correspond with the PBS detection of circulating plasma cells (PBS-PC) remain undetermined. It is important to understand this comparison better to categorize PCL based on PBF. Patients and Methods: This is a retrospective cross-sectional diagnostic accuracy study. We reviewed results of patients diagnosed with plasma cell dyscrasia at the Mayo Clinic from January 2011 to December 2020. The presence of circulating tumor plasma cells (CTC) in encounters was evaluated using peripheral blood flow cytometry (PBF) and peripheral blood smear (PBS) for plasma cells (PBS-PC). PBS-PC was measured as a percentage of plasma cells (PC) in a 100-cell manual differential smear count, and PBF was expressed as the number of plasma cell events per 150,000 peripheral blood mononuclear cells (PBMCs) (Ficoll-isolated peripheral blood mononuclear cells using antibodies to CD38, CD138, CD19, CD45, kappa, lambda, sensitivity (Sn)=6.7x10-5). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of PBS with respect to PBF were calculated. For threshold analysis, four groups were defined: A = absent PBS-PC, C = ≥1% and &lt;5%, D = ≥5%. Sensitivity and specificity of detecting PBS-PC (y-axis) for groups A vs. B, B vs. C, and C vs. D were plotted against CTC levels on PBF (x-axis) to determine the best cut-off. Area Under the Curve (AUC) was calculated to determine accuracy. Agreement analysis was done for internal validation and reliability assessment. Results: 6066 test records of CTC were reviewed. Circulating tumor plasma cells (CTC) by peripheral blood flow cytometry (PBF) were reported in 1610 (26.5%) instances, and peripheral blood smear for plasma cells (PBS-PC) in 226 (3.7%) tests. Peripheral blood smear (PBS) demonstrated a sensitivity of 9.3%, specificity of 99.5%, positive predictive value (PPV) of 86.7%, and negative predictive value (NPV) of 75.3% when compared to peripheral blood flow cytometry (PBF). The correlation between PBS-PC% and CTC was weakly positive (Spearman's rho=0.27, p&lt;0.01). The median (Q1, Q3) of circulating tumor plasma cells (CTC) for group A (n=5840) was 0 (0, 0), group B (n=82) was 780 (97.75, 4012.75), group C (n=67) was 1801 (61.50, 8723.50), and group D (n=77) was 20518 (2296, 41349) (p-value &lt;0.001). On post-hoc analysis, all pairs had significant differences in CTCs. To distinguish between A and B, a threshold of 32.5 for CTC demonstrated a sensitivity of 81.8% (AUC=87.8%), and to distinguish B and C, 1125 demonstrated a sensitivity of 59.4% (AUC=63.2%). To distinguish between C and D, 5875 for CTC demonstrated a sensitivity of 68.8% (AUC=74.6%). Agreement Analysis: The Bland-Altman plot demonstrates a slight positive bias between the Clonal Event % and %PBS-PC values (mean of difference = 0.28). The variability of differences increases with higher mean values, indicating a potential proportional bias. All predicted thresholds lie within the limits of agreement (LoA) (upper: 6.13, lower: -5.58) and are therefore reliable. The precision range (upper: 0.35, lower: 0.2) is narrower for the predicted thresholds. The methods should not be compared beyond a circulating tumor plasma cell (CTC) count of 9,195. Conclusion: Detection of circulating tumor plasma cells (CTC) by peripheral blood smear (PBS) is very specific but not sensitive and can be improved by peripheral blood flow cytometry (PBF) detection of CTC. Important clinical cutoffs by morphology (presence and ≥5%) have their counterparts by PBF (32 and 5875 out of 150,000 peripheral blood mononuclear cells (PBMC), respectively). The predicted thresholds are reliable. The study is retrospective and may not be generalizable across all demographics and disease severity. Circulating tumor plasma cell (CTC) values aren't absolute counts and may not be generalizable for low white blood cell (WBC) counts.

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 &lt;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 &gt; 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 = &lt;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.

Mutations in genes that code for RAS isozymes (N- and K-) are the most common (40-50%) somatic variations in multiple myeloma (MM). While ~46% of patients with newly diagnosed MM carry a RAS/Raf mutation, &gt;64% of patients with refractory/relapsed MM carry these mutations. RAS activation can also occur from upstream signaling through receptor tyrosine kinases (RTK) or loss-of-function mutations in GTPase-activating proteins (GAPs), which are prevalent in MM. Although covalent inhibitors targeting KRAS alleles are in various stages of clinical development, multiple mechanisms of resistance have been reported. We discovered and developed a novel, highly potent, and selective pan-RAS inhibitor, ADT-007, capable of suppressing MAPK/AKT signaling by blocking GTP activation of RAS. Here, we show that ADT-007 is effective against MM, particularly those MM cell lines harboring KRAS and NRAS mutations that are representative of relapsed/refractory myeloma (RRMM). For these studies, we compiled a panel of over 50 human myeloma cell lines (HMCLs) with broad biological and genetic heterogeneity that represent innate drug-response/resistance (refractory disease), as well as 10 pairs of parental and clonally-derived proteasome inhibitor (PI)- and immunomodulatory drug (IMD)- resistant HMCLs as models of acquired resistance (relapse). Using CRISPR-cas-directed gene editing, we also have generated clonal NRAS and KRAS mutants of drug-sensitive myeloma lines that initially had two wild-type alleles. All cell lines have been authenticated using the GenePrint 24 System and tested for mycoplasma contamination. First, we performed predictive analysis using single-cell RNA sequencing (scRNAseq; 10X Genomics) on all MM cell lines and demonstrated the potential efficacy of ADT-007 based on the subclonal expression of the target genes/pathways. Using in vitro chemosensitivity assays, ADT-007 was highly potent and effective in killing chemo-resistant and RAS-mutant myeloma cells as a single agent with IC50 values ranging from 0.76 to 12 nM with synergistic benefits if combined with PIs and IMDs. Combination indices (CI) were found to be consistently below 0.9, indicating a synergistic drug interaction. (Drug synergy was determined by CalcuSyn software based on Chou-Talalay's CI method and the isobologram algorithm). Caspase 3/7 assay and flow cytometry (Annexin V-FITC + propidium iodide) confirmed apoptosis induction by ADT-007. Furthermore, the in vitro efficacy of ADT-007 was significantly better (nM vs. µM IC50) than cyclorasin B4-27, a bicyclic peptidyl that has been reported as a potent pan-RAS inhibitor against several other cancers, and RMC-6236, a multi-selective noncovalent RAS(on) inhibitor which is in clinical trial for patients with advanced solid tumors harboring G12X, G13X, and Q61X mutations. Pre-vs-post-treatment bulk-RNA sequencing followed by pathway analysis (using Ingenuity Pathway Analysis and Gene Set Enrichment Analysis) showed that ADT-007 suppressed KRAS and NRAS in a dose-dependent manner. Immunoblotting analysis confirmed the dose-dependent reduction of protein markers implicated in cell survival and chemotherapeutic resistance in myeloma, including c-myc, Ki-67, NFkB, IRF4, IKZF1 (Ikaros) and IKZF3 (Aiolos). Finally, we performed pre-vs-post-treatment single-cell transcriptomics analysis, which revealed a distinct shift in clusters representing myeloma single-cell subpopulations following ADT-007 treatment. High-dimensional mass cytometry (cytometry by time of flight or CyTOF) analysis using heavy metal-conjugated proteins in RRMM patient bone marrow-derived primary myeloma cells is currently underway to confirm the cytotoxic effect of ADT-007 ex vivo. ADT-1004 is an orally bioavailable prodrug of ADT-007 designed to improve water solubility and metabolic stability. ADT-1004 has shown strong antitumor activity in highly aggressive and clinically relevant mouse models of pancreatic cancer at dosages, is well tolerated, and is being developed by the NCI Stepping Stones program. Next, we plan to evaluate the antitumor activity of ADT-1004 in mouse xenograft models of human myeloma using immunocompromised mice. Our research will lay the groundwork for future development efforts needed to advance ADT-1004 to clinical trials involving patients with RRMM.