Gonsalves, Wilson I.

Abstract As patients with relapsed/refractory multiple myeloma (RRMM) continue to live longer, they might get exposed to most available drugs and drug classes during the disease course. For such late line RRMM or among patients without access to novel therapies, retreatment with a drug that the disease had previously been refractory to might be one option. In this retrospective study, we describe 315 patients with RRMM at our institution who were retreated with a drug that the disease had been previously refractory to. We found an overall response rate of 56.2% and a median progression-free survival (PFS) of 11 months with retreatment. Patients with a longer time on initial therapy with the index drug (>28.4 months) had a superior PFS with retreatment (median PFS, 16.9 vs 8.1 months; P < .001). Similarly, patients with a longer time gap between the initial line of therapy with index drug and retreatment with index drug (>46.1 months) had better PFS with retreatment (28.2 vs 8.9 months; P = .016). In conclusion, retreatment with a previously refractory drug is a viable therapeutic option for RRMM, with the most significant benefit derived in disease demonstrating sensitivity to initial drug exposure and among those with a longer gap between initial drug exposure and retreatment.

7558 Background: Survival in patients with multiple myeloma (MM) continues to improve with the newer therapies, but there is no clear evidence of a cure and patients continue to relapse. However, most patients have the most extended period without progression with their first-line therapy, and subsequent therapies often provide a shorter duration of response due to the use of drugs with overlapping mechanisms of action and, more importantly, a shorter first remission, pointing toward more aggressive disease biology. With newer immunotherapies being used at 1st relapse, this may change. We designed this study to explore the natural history of MM after the 1st relapse and define the predictors of outcome after the initial relapse. Methods: We identified all patients in the Mayo Clinic database diagnosed between Jan 2004-June 2019 who had had initial disease progression. The study cohort included 2005 patients. We explored the overall survival (OS) from the time of documented disease progression or the start of second-line treatment in patients who had not met IMWG criteria before second-line therapy. Front-line therapy was grouped into those with either an IMiD or PI, both IMiD and PI, daratumumab with IMiD and PI, and none of these agents. The IMiD and PI were always used with dexamethasone with or without an alkylator. Results: The median age was 63 (range 24-95) years and 60% were male. The median estimated follow-up from diagnosis for all patients was 86 mos. (95% CI; 82, 88) and the median time to progression from the start of therapy was 25 mos. (95% CI; 24, 26). The median OS from the first progression was 45 mos. (95% CI; 42, 50), 36 mos. for those diagnosed before 2009, and 52-53 mos. for those diagnosed later. On univariate analysis, age <70 at 1st relapse, RISS I, novel agents in initial therapy, CR in the first line, diagnosis after 2009, initial remission >18 mos, and initiation of therapy before IMWG progression were all associated with improved OS after 1st relapse (Table). On multivariate analysis, age <70, RISS I, initial remission >18 mos, and initiation of therapy before IMWG progression were all associated with improved OS after 1st relapse. Conclusions: The study provides an estimate of the outcomes and significant predictors of outcomes after 1st relapse in patients with MM. These factors should be taken into consideration when designing clinical trials in this patient population. In particular, these factors identify a high-risk group of patients not always identified by baseline characteristics and should be the focus of future trials. [Table: see text]

AbstractBackgroundPrecursor plasma cell disorders such as monoclonal gammopathy of undetermined significance (MGUS) always precede the development of active malignancies such as multiple myeloma (MM). There is a need for novel biomarkers to identify those patients with such precursor plasma cell disorders who rapidly progress to MM. Plasma‐derived extracellular vesicles (EVs) may serve as a reservoir of potential biomarkers that can shed light on the pathogenesis and disease biology of MM.MethodsThis study isolated small EVs (SEVs) and large EVs (LEVs) from the platelet‐poor peripheral blood plasma of MGUS (n = 9) and MM (n = 12) patients using the size exclusion chromatography‐based method and evaluated their proteome using a label‐free proteomics workflow.ResultsIn total, 2055 proteins were identified in SEVs, while 2794 proteins were identified in LEVs. The transferrin receptor (or CD71) protein was upregulated in both populations of EVs derived from MM patients compared to MGUS patients and was of prognostic significance. Similarly, three isoforms of serum amyloid A (SAA) protein, SAA1, SAA2, and SAA4, were also highly upregulated in SEVs within MM patients relative to MGUS patients. Finally, CD40 expression was also higher in the LEVs derived from MM patients than in MGUS patients.ConclusionsThis study demonstrates the feasibility of successfully isolating both SEVs and LEVs from the peripheral blood of patients with plasma cell disorders and quantifying protein biomarkers within these EVs that could be of prognostic and diagnostic interest.

PURPOSE Patients with Waldenström macroglobulinemia (WM) have disparate outcomes. Newer therapies have emerged since the development of International Prognostic Scoring System, and MYD88 L265P mutation is now frequently assessed at diagnosis, warranting reexamination of the prognostic parameters. PATIENTS AND METHODS We reviewed records of 889 treatment-naïve patients with active WM, consecutively seen between January 01, 1996, and December 31, 2017, to identify clinical predictors of overall survival (OS) in univariate analyses. Patients with complete data for the parameters significant on the univariate analyses (n = 341) were included in a multivariable analysis to derive a prognostic model, subsequently validated in a multi-institutional cohort. RESULTS In the derivation cohort (n = 341), age (hazard ratio [HR], 1.9 [95% CI, 1.2 to 2.1]; P = .0009), serum lactate dehydrogenase (LDH) above upper limit of normal (HR, 2.3 [95% CI, 1.3 to 4.5]; P = .007), and serum albumin <3.5 g/dL (HR, 1.5 [95% CI, 0.99 to 2.3]; P = .056) were independently prognostic. By assigning a score of 1 point each to albumin <3.5 g/dL (HR, 1.5) and age 66-75 years (HR 1.4) and 2 points for age >75 years (HR, 2.6) or elevated LDH (HR, 2.3), four groups with distinct outcomes were observed on the basis of the composite scores. Five-year OS was 93% for the low-risk (score 0), 82% for low-intermediate risk (score 1), 69% for intermediate-risk (score 2), and 55% for the high-risk (score ≥3; P < .0001) groups. In the validation cohort (N = 335), the model maintained its prognostic value, with a 5-year OS of 93%, 90%, 75%, and 57% for the four groups, respectively ( P < .0001). CONCLUSION Modified Staging System for WM (MSS-WM), utilizing age, albumin, and LDH is a simple, clinically useful, and externally validated prognostic model that reliably risk-stratifies patients with symptomatic WM into four groups with distinct prognosis.

Background:Waldenström Macroglobulinemia (WM) is a rare, indolent B‐cell lymphoplasmacytic malignancy. Patient outcomes are highly heterogeneous, with a proportion of patients surviving less than 5 years (short survivors) and another proportion that survive longer than 10 years. The laboratory parameters in the currently used International Prognostic Scoring System for WM (IPSSWM) include hemoglobin, serum IgM, platelet count, and serum β2‐microglobulin.Aims:We aim to identify unique patient characteristics and prognostic features associated with short survival in WM.Methods:The medical records of patients with active WM that were diagnosed at Mayo Clinic Rochester, Arizona, and Florida between January 1st, 1996 and December 31st, 2013 were reviewed. The patients with smoldering WM were excluded. Cohorts of patients who either survived ≤ 5 years (Short Survival Group) or those with an overall survival (OS) ≥ 10 years (Long Survival Group) from the diagnosis of active disease were compared. Survivors with a follow‐up of ≤ 5 years were not included in the analyses. Two‐sided Wilcoxon rank sum test and Chi square/Fisher's exact test were used to compare the continuous and categorical variables, respectively. The variables that were statistically significant on univariate analysis (P < 0.05) were included in a multivariate logisitic regression analysis.Results:Of 893 consecutively seen WM patients (median follow‐up of 9 years [95% CI 8.4–9.7]), we identified 387 patients who could be categorized into either the Short Survival Group (n = 171 patients, 44%) or the Long Survival Group (n = 216, 56%). The Short Survival Group had a median OS of 2.4 years (2.1–2.8) and median age at diagnosis of 73 years (42–93), while the Long Survival Group (n = 216, 56%) had a median OS of 18.9 years (16‐NR) and median age at diagnosis of 62 years (31–85). The baseline characteristics and significant findings between the two groups are listed in the Table. Parameters significant on univariate analysis included age >65 years, albumin < 3.5 g/dL, β2‐microglobulin >3 μg/ml, and LDH > upper limit of normal (ULN). On multivariate analysis, albumin <3.5 g/dL and LDH > ULN were independently associated with short survival. Among the Long Survivors, 60 (28%) patients survived 15 years or more.Summary/Conclusion:Lactate dehydrogenase above the ULN and serum albumin <3.5 g/dL are independent biomarkers of short survival in WM. The MYD88 L265P status and the size of serum IgM are not prognostic in WM. Our data suggest the need for simplification of the current staging system with the use of widely available markers: serum albumin and lactate dehydrogenase.image

Background: GLUT4 inhibition via the use of a protease inhibitor, such as nelfinavir (NEL), is an attractive therapeutic option in multiple myeloma (MM), given the dependence of MM cells on glucose. Furthermore, combining a GLUT4 inhibitor with an oxidative phosphorylation inhibitor, such as metformin (MET), may counter the possibility of therapeutic resistance to GLUT4 inhibition in MM cells, showing synergistic promise (Dalva-Aydemir et al., Clin Can Res 2015). In addition to GLUT4 inhibition, NEL also lowers the cytotoxicity resistance of MM cells against proteasome inhibitors such as bortezomib (BOR) (Driessen et al., Blood 2018). Thus, this study evaluated the safety and tolerability of repurposing MET and NEL, in combination with BOR for the treatment of relapsed/refractory MM (RRMM) that had progressed on all standard of care (SOC) therapies. Methods: This trial utilized a 3+3 dose escalation design with 3 dose levels planned for up to a maximum of six (21-day) cycles. MET was administered for 14/21 days and started at a dose of 500 mg BID with plans to be investigated at a maximum dose of 1000 mg BID. NEL was administered for 14/21 days and started at a dose of 1250 mg BID with plans to be investigated to a maximum dose of 2500 mg BID. SubQ BOR was administered on days 1, 8, and 15 of a 21-day cycle at a dose of 1.3 mg/m 2 to a portion of patients. Patients with RRMM were required to have had 2 prior lines of therapy and prior exposure to proteasome inhibitors (PIs), immunomodulators (IMiDs), and Anti-CD38 monoclonal antibodies. The primary objective was to determine the maximal tolerated dose (MTD) of this combination. The secondary objective was to evaluate the safety as well as the overall response rate (ORR) of this combination. This trial was funded by the Helen Diller Family Foundation. Results: From 4/2019 until 9/2022, nine patients were accrued with a median age of 65 (range: 42-81) that received a median of 7 prior lines of therapy (Range: 6-13). All but one patient had a prior autologous stem cell transplant. Only one patient was not triple-class refractory, and 2/3 rd (n = 6) also had prior anti-BCMA therapy. The first three patients received only MET (500 mg BID) and NEL (1250 mg BID) at the first dose level for up to one cycle before experiencing progressive disease and coming off the study. Given the limited activity of MET and NEL in the initial treatment of these three patients, two subsequent amendments to the protocol allowed for the upfront addition of BOR 1.3 mg/m2 to the original combination, as well as shortened the DLT evaluation period from two cycles to just one. Thus, the following six patients received MET (500 mg BID) and NEL (1250 mg BID) at the first dose level in addition to weekly BOR at 1.3 mg/m2. Four (44%) patients experienced grade 3+ hematological AEs and six (67%) experienced grade 3+ non-hematological AEs. The most common hematologic grade 3+ AE observed was anemia (44%). The nonhematologic grade 3+ AEs observed were dyspnea, fatigue, nausea, and vomiting (11% each). None of the AEs were possibly related to treatment, suggesting good overall safety of the combination. While eight of nine patients have since died of progressive disease, no deaths were attributable to the treatment. All six patients who received BOR upfront with MET and NEL were previously refractory to BOR in prior lines of therapy; however, none had received BOR as their last line of therapy prior to accrual to this study. Four of these six patients had progressive disease after one cycle of therapy and went off study. However, the remaining two were able to receive 2 or more cycles of therapy, with one experiencing an unconfirmed minor response (MR) in the first cycle and the other experiencing stable disease (SD) for all six cycles. The patient who experienced SD was safely able to transition to a subsequent clinical trial utilizing an anti-BCMA bispecific antibody therapy and remains alive at the time of this analysis. The study was closed before accrual to the next dose level was started. Conclusions: This is the first study to evaluate the safety and efficacy of this repurposed drug combination in this very difficult-to-treat population of RRMM. While no ORR was observed, identification of biomarkers used for selection of patients with no other SOC options who could experience at least SD responses may be beneficial in allowing this combination to slow or stabilize the disease progression until other novel therapies or clinical trials are available.

Background: It has been recently demonstrated that altered lipid metabolism involving increased free fatty acids (FFAs) uptake supports the growth and proliferation of MM cells (Panaroni et al. Blood 2022; Farell et al. Elife 2023). Whether the availability of FFAs in the bone marrow (BM) microenvironment is associated with the pathogenesis of MM from MGUS has not been previously evaluated. Thus, we evaluated if individual species of FAs or FA-containing lipids such as triacylglycerols (TAGs), diacylglycerols (DAGs), and monoacylglycerols (MAGs) are differentially present between the BM microenvironment of MGUS and MM patients. Methods: Lipid profiles of BM plasma samples (reflective of the BM microenvironment) from patients with a spectrum of plasma cell disorders (22 MGUS and 24 MM (15 newly diagnosed and 9 relapsed/refractory)) were acquired by liquid chromatography (LC)/tandem mass spectrometry (MS), and individual lipid species were quantified based on single-point quantification using 55 isotopically labeled internal standards. Concentration-based lipid species data was analyzed by the web-based tool MetaboAnalyst 5.0. Data was normalized by quantile normalization, log transformed and scaled by Pareto scaling. p values &lt;0.05 were considered significant. Results: A total of 993 distinct lipid species were quantified by the MS-based targeted lipidomics assessment. Of these lipid species, the levels of individual mid-chain (≤50 carbon chain length) and long-chain (≥52 carbon chain length) polyunsaturated TAGs were the most differentially present in the BM plasma of MM compared to MGUS patients (Figure 1A). Even though a principal component analysis (PCA) involving all lipid species showed moderate separation of MM from MGUS patients, five MGUS patients (categorized as MGUS-other (MGO)) who clustered more towards MM patients compared to the remaining MGUS patients had a distinct pattern of individual mid and long-chain polyunsaturated TAG levels that were comparable to MM patients (Figure 1B). Furthermore, the proliferation rate of clonal plasma cells in the BM of these MM and MGUS as measured by the S-phase% was found to be directly correlated with the level of long-chain polyunsaturated TAGs. Conclusions: Mid and long-chain polyunsaturated TAGs are present in lower and higher levels, respectively, in the BM microenvironment of MM compared to MGUS patients. These findings continue to support the importance of FA-containing TAGs and other lipids in the pathogenesis of MM. Future confirmatory studies evaluating the biological significance of these differences are required to determine if they can be exploited for diagnostic and therapeutic purposes.

Background: Waldenström Macroglobulinemia (WM) is an indolent lymphoma with heterogeneous outcomes. The recently developed, Revised International Prognostic Scoring System for WM (rIPSS-WM) did not examine the prognostic impact of MYD88L265P, a somatic alteration present in most patients with WM. Moreover, rIPSS-WM could only be partially validated in an external cohort. Here, we report the performance of rIPSS-WM and propose a refined prognostic model with external validation. Methods: We reviewed medical records of treatment-naïve patients with active WM consecutively seen at Mayo Clinic, Rochester (MCR) between 01/01/1996 and 12/31/2017. We applied the rIPSS-WM model in patients with data available for all required parameters, including age, serum beta-2 microglobulin (β2M), serum lactate dehydrogenase (LDH) and serum albumin at diagnosis to assess the prognostic utility of this model. We then identified the dichotomized clinical and laboratory parameters prognostic for overall survival (OS) by univariate analyses (UVA) in our cohort. The significant parameters were analyzed to independently predict OS in a multivariable analysis (MVA) and to create a prognostic model, which was subsequently validated in an independent multi-institutional cohort. Results: We identified 889 patients with active WM at MCR, with a median follow-up of 8.2 [95% confidence interval (CI): 7.5-9] years. The estimated median OS for this cohort was 10.6 (95%CI: 9.7-11.4) years. Patients with available data in this cohort for the validation of rIPSS-WM (n=241) were risk stratified into very low (n=46), low (n=64), intermediate (n=58), high (n=46) and very-high risk groups (n=27) per rIPSS-WM, with the respective 5-year OS rates of 96%, 76%, 72%, 77% and 32%, demonstrating overlapping survival curves for the low, intermediate and the high-risk groups. Because rIPSS-WM could not be validated, we used the data from the MCR cohort and identified age at diagnosis of active WM, LDH &gt;upper limit of normal (ULN), β2M &gt;3µg/mL and albumin &lt;3.5g/dL as statistically significant prognostic markers for OS on UVA. Notably, the presence of MYD88 L265P did not impact OS [median 11.4 years (95%CI: 10.1-not reached (NR) for MYD88 L265P genotype (n=231) versus 10 years (95% CI: 8.1-NR) for MYD88 WT genotype (n=65); p=0.33]. On MVA, LDH &gt;ULN (HR 2.34), serum albumin &lt;3.5 g/dL (HR 1.5) and age groups 65-75 years (HR 1.4) and &gt;75 years (HR 2.6) were independently prognostic. Based on comparable HRs, we assigned a score of 1 point each to serum albumin &lt;3.5 g/dL and age group 66-75 years and similarly, 2 points each for age &gt;75 years and serum LDH &gt;ULN per their impact on OS. Patients with the composite scores of 0, 1 and 2 were categorized as low risk, low- intermediate risk and intermediate risk, respectively. Due to similar OS for the scores of 3 to 5, these were combined to form the high-risk group of our proposed model: Modified Staging System for WM (MSS-WM). The median OS was 14.6 years [95%CI: 9.1 years-NR] for low-risk (score 0, n=71, 21%), 11.2 years (95% CI: 9.1-15.2 years) for low-intermediate risk (score 1, n=110, 32%), 8.1 years (95% CI: 6.4-12.2) for intermediate risk (score 2, n=81, 24%) and 5.5 years (95 % CI: 3.9-11 years) for the high-risk group (score ≥3, n=79, 23%); p&lt;0.0001. In this derivation cohort, the 5-year OS rate was 93%, 82%, 69% and 55% and 10-year OS rate was 60%, 53%, 45% and 30% for the low, low-intermediate, intermediate, and high-risk cohort, respectively ( Figure 1A). We also validated MSS-WM using competing risk analysis (p=0.001) and in the cohort of rituximab treated patients (p&lt;0.0001). We then used data from an independent series of 335 treatment-naïve symptomatic patients from academic institutions (n=5) across the US and Europe for external validation of the MSS-WM model. The median follow-up for the validation cohort was 6.3 years (95% CI: 5.5-7.2 years). The 5-year OS was 93%, 90%, 75% and 57% and the estimated 10-year OS was 91%, 80%, 64% and 35% for the low risk (n= 86, 26%), low-intermediate (n=107, 32%), intermediate (n=86, 26%) and high-risk (n=59, 18%) cohorts, respectively (p&lt;0.0001, Figure 1B). Conclusions: Our proposed model, MSS-WM, is a simple, clinically useful, externally validated model that reliably risk stratifies previously untreated patients with active WM into four groups that have distinct outcomes based on the composite scores derived from the patients' age, serum albumin and serum LDH at diagnosis.

Background: Although recently available immune-based approaches in multiple myeloma produce high response rates, curative outcomes have not yet been achieved, which highlights the need for new agents that further activate the immune system without increasing toxicity. ORIC-533 is a highly potent and selective, orally bioavailable, small molecule inhibitor of CD73, an enzyme expressed by various cell types, including immune cells and which catalyzes the generation of adenosine from adenosine monophosphate (AMP) (Allard 2019). Adenosine itself is highly immunosuppressive, diminishing activity of a range of immune cell types, including T, NK, and dendritic cells (Young 2014). By blocking adenosine production from AMP via inhibition of CD73, ORIC-533 has demonstrated the ability to restore and enhance immune function. Multiple myeloma (MM) patient bone marrow (BM) contains multiple cell types that also express CD73, including immune cells, cancer-associated fibroblasts, mesenchymal stem cells, and endothelial cells (Allard 2019). Moreover, elevated adenosine levels in the MM BM niche correlate with disease progression (Horenstein 2016; Yang 2020). We have previously observed that CD73-mediated adenosine activity suppresses the cytolytic antitumor immune function in the MM BM milieu (Ray 2022). ORIC-533 treatment reduced adenosine production, overcame this immune suppression with evidence of restored DC-mediated priming and activated cytotoxic CD8 + T-cell function, and significantly enhanced immune cell cytolytic behavior against RRMM tumor cells in autologous patient ex vivo experiments (Junttila 2022), making ORIC-533 a potential immunotherapy for patients with MM. Methods: ORIC-533-01 (NCT05227144) is an ongoing i3+3 Phase 1b dose escalation study in patients with RRMM. The primary objectives are to determine single agent safety/tolerability and pharmacokinetics (PK) of ORIC-533 to select the RP2D. Pharmacodynamic assessments include measurement of CD73 functional activity in serum and BM, as well as enumeration of immune cell subsets and activation state in blood and BM. Patients are also evaluated for clinical efficacy using IMWG criteria. Results: As of 23 June 2023, 17 patients received ORIC-533 once daily across 4 dose levels (400 mg to 1600 mg). All patients were triple-class refractory, 88% were penta-refractory, and 59% also received prior anti-BCMA/CD3 bispecific therapy or anti-BCMA CAR-T therapy. Overall, ORIC-533 was very well tolerated, with 5 patients experiencing a total of 10 treatment-related adverse events (TRAEs). Fatigue was the only G3 AE and the only TRAE seen in more than 1 patient (1 event each of G3 and G2); all other events seen in 1 patient each, were G1 or G2 in severity, and of no specific system organ class. No dose limiting toxicities, no Grade ≥4 TRAEs, and no treatment-related serious adverse events have been observed. PK showed increased exposure with dose with a plasma half-life of ~24 hrs. Soluble CD73 enzymatic activity was nearly completely inhibited by C1D15 in serum of all patients across all dose levels, while the largest relative suppression in surface CD73 activity in BM cells was observed at the highest dose level. There was also evidence for increases in the abundance of circulating NK and CD8+ T cells after 1 treatment cycle, with preliminary evidence of enhanced CD8+ T-cell activation at the highest dose levels tested in both peripheral blood and BM. In addition, early evidence of single agent clinical activity was observed. Conclusions: ORIC-533 has demonstrated an acceptable safety profile and preliminary evidence of immune activation in a heavily pretreated RRMM patient population. Enrollment is ongoing and updated data will be presented.