Post Autologous Stem Cell Transplantation Research Articles

Assessing Outcomes in Patients with Multiple Myeloma Post-Autologous Stem Cell Transplantation: Contrasting the Effects of Melphalan Dosages at 200mg/m2 versus 140mg/m2

BackgroundNo standard criteria for dose reduction exists for high-dose melphalan for autologous stem cell transplantation (ASCT) for multiple myeloma (MM) due to limited and conflicting evidence. ObjectiveTo evaluate efficacy and safety of standard dose (200 mg/m2=Mel200) versus reduced dose (140 mg/m2=Mel140) of melphalan in patients with MM undergoing ASCT. Design: A single-center retrospective review of adults with MM for their first ASCT between January 1, 2010, and November 1, 2022, who received Mel200 or Mel140 as conditioning. Primary endpoint was progression-free survival (PFS). Secondary safety and efficacy endpoints included overall survival (OS), incidence of febrile neutropenia and acute kidney injury, and time to engraftment. Subgroup analyses were performed based on patient age and renal function. ResultsA total of 322 patients were included in the study, 240 in the Mel200 group and 82 in the Mel140 group. Baseline demographics were similar except patients receiving Mel140 were on average older and had worse kidney function. PFS at 2 years was not different between groups (P = 0.2335). No difference existed in 2-year PFS or OS for patients <65 years of age versus ≥65 years of age or for patients with CrCl 30–59 mL/min versus CrCl ≥60 mL/min within either Mel200 group or Mel140 group (all P > 0.05). No differences existed between groups across all secondary outcomes. ConclusionReduced doses melphalan showed no differences in safety or efficacy outcomes versus standard dose even when analyzed based on age and renal function. Larger randomized controlled trials need to be performed to validate these findings. Micro-AbstractDespite varied evidence and lack of specific thresholds, dose reduction of melphalan before autologous transplantation is considered for patients of older age or reduced renal function. This retrospective study of 322 patients compared melphalan 200mg/m2 vs 140mg/m2 finding no differences in efficacy, such as 2-year progression-free survival, or safety outcomes between groups, including when analyzed by age and renal function.

Real-world advantage and challenge of post-autologous stem cell transplantation MRD negativity in high-risk patients with double-hit multiple myeloma

BackgroundAutologous stem-cell transplantation (ASCT) remains a beneficial approach for patients with newly diagnosed multiple myeloma (NDMM) in the age of novel therapeutic agents. Nevertheless, limited real-world data is available to establish criteria for identifying high-risk ASCT patients.MethodsWe analyzed outcomes for 168 NDMM patients who underwent ASCT at our center from December 2015 to December 2022. We investigated the impact of the number of high-risk cytogenetics (HRCA), defined as t(4;14), t(14;16), 1q21 gain/amplification, and del(17p), as well as the post-ASCT minimal residual disease (MRD) status as prognostic indicators. We assessed progression-free survival (PFS) and overall survival (OS), and focused on identifying risk factors.ResultsThe cohort included 42% of patients (n = 71) with 0 HRCA, 42% (n = 71) with 1 HRCA, and 16% (n = 26) with ≥ 2 HRCA. After a median follow-up of 31 months, the median PFS was 53 months (95% CI, 37–69), and OS was not reached for the entire cohort. Despite similar rates of MRD-negativity post-ASCT, patients with ≥ 2 HRCA, termed “double hit” (DH), had a significantly higher risk of progression/mortality than those with 0 or 1 HRCA. Multivariate analysis highlighted DH (HR 4.103, 95% CI, 2.046–8.231) and MRD positivity post-ASCT (HR 6.557, 95% CI, 3.217–13.366) as adverse prognostic factors for PFS, with DH also linked to inferior OS. As anticipated, DH patients with post-ASCT MRD positivity displayed the poorest prognosis, with a median PFS of 7 months post-ASCT. Meanwhile, DH patients with MRD negativity post-ASCT showed improved prognosis, akin to MRD-negative non-DH patients. It is noteworthy to exercise caution, as DH patients who initially achieved MRD negativity experienced a 41% cumulative loss of that status within one year.ConclusionsThis study strongly advocates integrating DH genetic assessments for eligible ASCT patients and emphasizes the importance of ongoing MRD monitoring, as well as considering MRD-based treatment adaptation for those patients in real-world settings.

Tumor integrin targeted theranostic iron oxide nanoparticles for delivery of caffeic acid phenethyl ester: preparation, characterization, and anti-myeloma activities.

Multiple myeloma (MM) is characterized by the accumulation of malignant plasma cells preferentially in the bone marrow. Currently, emerging chemotherapy drugs with improved biosafety profiles, such as immunomodulatory agents and protease inhibitors, have been used in clinics to treat MM in both initial therapy or maintenance therapy post autologous hematopoietic stem cell transplantation (ASCT). We previously discovered that caffeic acid phenethyl ester (CAPE), a water-insoluble natural compound, inhibited the growth of MM cells by inducing oxidative stress. As part of our continuous effort to pursue a less toxic yet more effective therapeutic approach for MM, the objective of this study is to investigate the potential of CAPE for in vivo applications by using magnetic resonance imaging (MRI)-capable superparamagnetic iron oxide nanoparticles (IONP) as carriers. Cyclo (Arg-Gly-Asp-D-Phe-Cys) (RGD) is conjugated to IONP (RGD-IONP/CAPE) to target the overexpressed αvβ3 integrin on MMcells for receptor-mediated internalization and intracellular delivery of CAPE. A stable loading of CAPE on IONP can be achieved with a loading efficiency of 48.7% ± 3.3% (wt%). The drug-release studies indicate RGD-IONP/CAPE is stable at physiological (pH 7.4) and basic pH (pH 9.5) and subject to release of CAPE at acidic pH (pH 5.5) mimicking the tumor and lysosomal condition. RGD-IONP/CAPE causes cytotoxicity specific to human MM RPMI8226, U266, and NCI-H929 cells, but not to normal peripheral blood mononuclear cells (PBMCs), with IC50s of 7.97 ± 1.39, 16.75 ± 1.62, and 24.38 ± 1.71μM after 72-h treatment, respectively. Apoptosis assays indicate RGD-IONP/CAPE induces apoptosis of RPMI8226 cells through a caspase-9 mediated intrinsic pathway, the same as applying CAPE alone. The apoptogenic effect of RGD-IONP/CAPE was also confirmed on the RPMI8226 cells co-cultured with human bone marrow stromal cells HS-5 in a Transwell model to mimic the MM microenvironment in the bone marrow. In conclusion, we demonstrate that water-insoluble CAPE can be loaded to RGD-IONP to greatly improve the biocompatibility and significantly inhibit the growth of MMcells in vitro through the induction of apoptosis. This study paves the way for investigating the MRI-trackable delivery of CAPE for MM treatment in animal models in the future.

Risk and Response Adapted Approach for Treatment of Myeloma: Pushing Autologous Transplant Down the Hierarchy

Background &amp; Significance: In current recommendations, consolidative autologous stem cell transplant (ASCT) is essential in management of NDMM. The IFM 2009 Trial showed that RVd followed by ASCT with 1-year lenalidomide maintenance was associated with a better PFS vs. RVd with 1-year lenalidomide maintenance alone (Attal M et al, NEJM 2017). A longer follow up (8 years) of IFM trial concluded that a delayed transplant (in 2 nd line) had no impact on the PFS2 (Perrot A et al, Blood 2020). We evaluated the merit of frontline ASCT (CR1) vs. post salvage ASCT (CR2) in light of indefinite maintenance therapy post novel triplet/quadruplet induction. Material &amp; Methods: We conducted this retrospective analysis, of symptomatic myeloma patients who underwent ASCT at Rajiv Gandhi Cancer Centre, Delhi between April 2017 and October 2022. Patients were segregated into 2 cohorts; a) ASCT CR1- who received 4 to 6 cycles of RVd (+/- Anti CD38 antibody) induction followed by transplant and indefinite maintenance and b) ASCT CR2- patients who relapsed after 4-6 cycles of RVd induction+maintenance then salvaged with 2 to 6 cycles of novel agent-based therapy (Carfilzomib/ Pomalidomide/ Daratumumab) followed by ASCT and indefinite maintenance. Patient characteristics were balanced for age, gender, ISS, RISS and high risk cytogenetics (Del p53, t(4;14), t (14;16), 1qGain, 1pDel, 13qDel). Response was assessed as per IMWG criteria. PFS was defined as the time from induction/salvage to progression on next line of therapy or death. Results: Of 161 patients included, we compared outcomes of ASCT CR 1 (N=122) to ASCT CR-2 (N=39). All patients received maintenance (PI/IMID or in combination) post ASCT. Significant patients in ASCT-CR2 received novel salvage therapy (Carfilzomib/ Pomalidomide/ Daratumumab) (CR1-14 % vs CR2-100%, p value- &amp;lt;0.01). 86% patients in ASCT CR1 received RVd. Both groups were substantially exposed to Lenalidomide. Median time from diagnosis to transplant was 5.9 months (range 4-12) in ASCT- CR1 group and 29.5 months (range 18-64) in ASCT CR2 group (p value- 0.004). After a median follow up of 44 months for ASCT CR1 vs. ASCT CR2, the ORR (97% vs. 95.4%, p=0.88) and CR (85% vs. 78%, p=0.67), respectively. 42.6% patients in ASCT CR1 and 38.4% patients in ASCT CR2 relapsed (p value- 0.4%). The median PFS for both groups (ASCT CR1 and ASCT CR2) were similar 45 months and 43 months, respectively, (p value- 1.09). The 1-, 3- and 5-year PFS showed a similar trend across cohorts (CR-1: 95%, 59.1%, 39.7% and CR-2: 84%, 57.1%, 41.3%). Patients with high-risk cytogenetics in ASCT CR 1 (N=50) had a better median PFS (25 months) compared to ASCT CR2 (N=16, median PFS=17.9 months, p=0.059), fig:1 though statistically insignificant. Table:1 No difference in PFS for standard risk noted (p=0.38). On regression analysis, factors predictive of progression were: ISS stage III (univariate only), high-risk cytogenetics, IMID based maintenance therapy. We noted better PFS in patients receiving &amp;gt;24 months of maintenance. Depth of response prior to transplant, Melphalan dosage and remission (CR1 vs CR2) did not predict progression. Conclusion: In the light of above findings, does transplant decision need re-sequencing? Our findings are not in agreement with the hypothesis that exposure to novel agents in relapsed/refractory settings leads to resistant clone selection under stress. The pattern of relapse in standard risk myeloma remains same across lines of therapy. Excellent response rates are observed with novel agents at relapse therefore delaying transplant appears reasonable in standard risk. High-risk myeloma represents a unique subset where patients experience early/aggressive relapse indicating that current therapy offers little modification of kinetics or natural history of disease. Changing treatment paradigm based on disease risk and response appears pragmatic. Myeloma is the disease of elderly with plethora at hand, its time to individualize.

Sequential Imaging with Diffusion-Weighted Whole-Body MRI (DW-MRI) and PET-CT Identifies Patients at High Risk of Relapse in Multiple Myeloma

Introduction: Although the vast majority of patients with newly diagnosed multiple myeloma (NDMM) achieve deep responses during first-line therapy, most of them face relapse over time. Focal lesions, which are seen in up to 80% of NDMM, play a crucial role in MM evolution and can act as reservoirs for relapse disease. As a consequence, the combination of imaging- and minimal residual disease (MRD) negativity has been defined as a new response category. However, the dynamics and location of focal lesions during the treatment course remains poorly characterized and the answer to what imaging modality should be used to visualize focal residual disease remains elusive. In this study, we employed two techniques, PET-CT and DW-MRI, at multiple pre-defined time points to longitudinally track resistant lesions and investigate the combined prognostic value of these imaging modalities with other prognostic markers. Methods: We included 170 NDMM patients who were diagnosed between the years of 2010-2015 to ensure sufficient median follow-up time, which was 10 years. Median age of the study cohort was 60 years (range: 34-76), 104 were male (61%), and 31 patients (18%) had high-risk according to gene-expression profiles. All patients underwent PET-CT and DW-MRI evaluation at three pre-defined timepoints: baseline, post autologous stem-cell transplantation (ASCT) and at relapse. Minimal residual disease testing (MRD) by 8 color flow cytometry at a sensitivity level of 10 -5 post ASCT was available for 70 patients. Results: At baseline, 144/170 patients (85%) presented with focal lesions. Both imaging modalities, PET-CT and DW-MRI, showed positive results in 116 patients (68%). However, 21 patients (12%) had focal lesions detectable only by DW-MRI, while 7 patients (4%) showed focal lesions solely in PET-CT. After ASCT, only 12 patients had PET-CT positive lesions, whereas DW-MRI detected focal lesions in 53 patients, indicating a much higher detection rate with DW-MRI. Overall, 55 out of 170 patients (32%) showed residual lesions at this time point. The 26 patients w/o focal lesions in both PET-CT and DW-MRI at baseline remained negative post ASCT. Except for one patient, focal lesions after ASCT were persistent from initial diagnosis. Of note, two-thirds of the patients had residual focal lesions in the humeri and/or femora, which is surprising given that myeloma is considered a disease of the axial skeleton. Next, we correlated the presence of residual lesions with baseline patient characteristics, including age, gender, stage, and cytogenetic risk factors. Compared to patients w/o residual lesions, PET-positive patients showed an enrichment of rISS stage III (7 vs 50%, p&amp;lt;0.001) and deletion 17p (10 vs 33%, p=0.04). In contrast, patients who were DW-MRI positive only showed no significant association with any of the investigated variables. Both PET- and DW-MRI positive lesions post ASCT were associated with poor PFS (median 1.5 and 2.4 years, respectively vs. 9.4 years in imaging-negative patients, p&amp;lt;0.001) and OS (median 3.7 and 5.7 years, respectively vs. 11.3 years, p&amp;lt;0.001). Importantly, in a multivariate model the adverse prognostic effect of residual lesions was independent of baseline risk factors. To increase the power of the following combined imaging/MRD analysis, we defined an “Imaging+” group, which included the patients with PET+ and/or DW-MRI+ focal lesions. Among the 20 patients who achieved MRD-negative and imaging-negative status, an excellent PFS was observed, with only three events occurring in an 8-year follow-up. Residual lesions despite MRD negativity were only seen in two patients, and one of them progressed after 1.5 years. Dismal PFS was seen for double-positive patients (median 1.4 years), significantly worse compared to patients with MRD positivity only (8.9 years). Conclusion: Taken together, DW-MRI captures more patients with prognostically relevant residual focal lesions compared to PET-CT and should therefore be considered as a preferable imaging modality post ASCT. The high number of residual lesions in the extremities suggests a role of humeri and femora as reservoirs for treatment-resistant cells, deserving further investigation. For patients with MRD and imaging double positivity post ASCT, prognosis is dismal and alternate therapeutic approaches should be considered.

Planned Interim Safety Analysis of the Phase 3 Randomized Trial of Selinexor and Lenalidomide Versus Lenalidomide Maintenance Post Autologous Stem Cell Transplant for Patients with Newly Diagnosed Multiple Myeloma (ALLG MM23; Sealand)

Introduction: Upregulation of Exportin 1(XPO1), a molecule that mediates nuclear export of tumor suppressor proteins, is associated with poor prognosis and resistance to immunomodulatory drugs (IMiD) and proteasome inhibitors in myeloma (MM). Selinexor (S) is an oral selective XPO1 inhibitor, that is approved in combination with bortezomib and dexamethasone to treat adult patients with MM who have received at least one prior therapy. We hypothesize that low dose S when combined with low dose lenalidomide (R) will be synergistic and will improve progression free survival (PFS) compared to R maintenance post autologous stem cell transplant (ASCT) in patients (pts) with transplant eligible (TE) newly diagnosed (NDMM). We report here the results of the planned futility analysis, after at least 30 patients had completed a minimum of 6 months follow-up in the phase III randomized SeaLAND (ALLG MM23) study (ANZCTR12620000291987). Method: Eligible pts were TE NDMM who have had 3 to 6 cycles of induction containing bortezomib (V), dexamethasone ± R. Registration occurred pre-ASCT; screening and randomization occurred from day 75 to 115 post-ASCT. Twenty pts in the lead in safety phase were given low-dose S [40mg (increased to 60mg from C2 if well tolerated) po D1,8,15,22] with R (15mg D1 to 21; 10mg in C1 to 3) in a 28-day cycle. Upon review by the independent safety committee in May 2023, after the first twenty pts had completed 2 cycles of SR, a starting dose of S of 40mg/week was deemed generally safe with no escalation recommended. Subsequent patients were randomized 1:1 to either SR (S capped at 40mg/week) or R. Primary objective was to determine 3-year-PFS; secondary objectives included safety/tolerability and additional efficacy measurements. Results: As of 30 May 2023, 117 pts (70% male) received maintenance (69 pts SR; 48pts R). 103 patients (61 SR and 42 R) had clean data at a cut-off date and were included in this analysis. Median (med) age was 60 (range 34-75). 27.4% of patients had high risk cytogenetics; ISS stage 1,2,3 occurred in 31.5%, 47% and 26.5%, respectively. Med follow-up for the overall group was 11.9 (0.3-28) months, with a med 10 (1-27) cycles [10 (1-27) SR; 9.5 (2-21) R] and 86.1% of patients continued treatment (83.1% SR; 90.7% R). All patients (n=103) had ≥ 1 treatment-emergent adverse event (TEAE); 64% grade (Gr) 3-4 (84% SR, 36% R); SAE occurred in 21% (28% SR, 12% R). Hematologic Gr 3-4 TEAEs were anemia (1.6% SR; 4.8% R), neutropenia (60.7 SR; 28.6% R) and thrombocytopenia (24.6% SR; 0% R). Gastrointestinal TEAE occurred in 50.4% of all patients (67.5% SR, 26.2% R). Diarrhea, nausea and vomiting in the SR (Gd 3-4)/R (Gd 3-4) group occurred in 26.3% (3.3%)/23.8% (2.4%), 57.1% (9.8%)/7.1% (0%), and 8.2% (1.6%)/0% (0%), respectively. The incidence of gastrointestinal TEAE in the SR group decreased from C3 onwards. Infections occurred in 41% of all patients (49% SR, 29% R); Gd 3-4 infections in 9 % (15% SR, 0% R). COVID-19 infections occurred in 16% (13% SR; 19% R), and all but one was Gd 1-2. 1 patient died (SR arm) due to progressive disease. In the SR group, the med RDI (relative dose intensity) of S was 66.7% (20.8-150%), and in the R group; the med RDI of R was 100% (33.3-100%). Most patients in the SR arm (n=61) tolerated S dose between 80mg (20mg per week) to 160mg (40mg per week), which remained consistent with time (figure 1). Conclusion: A dose of S 40mg weekly was generally tolerable when combined with R 10-15mg days 1-21 in a 28-day cycle, as maintenance therapy post ASCT. The safety profile was consistent with each of S and R individually. Recruitment in the ALLG MM23 (SeaLAND) study is ongoing and updated safety and treatment data will be presented at the meeting. Acknowledgement: Patients, their families, and participating ALLG members and member sites. ALLG acknowledges the support of Karyopharm for funding and Selinexor supply.

The Impact of Epstein-Barr Virus Infection on Second Cancer Development in Newly Diagnosed Myeloma Patients Treated with Lenalidomide in the UK NCRI Myeloma XI Trial

Background Several factors have been linked to second primary malignancy (SPM) development in myeloma patients, including advanced age, immunocompromise and therapy, such as melphalan and lenalidomide (len). The impact of infection, including EBV is yet to be elucidated. Here we address this in the context of the UK NCRI Myeloma XI Trial for newly diagnosed transplant eligible (TE) and transplant non-eligible (TNE) patients. Methods Myeloma XI was a phase III, randomised, multi-centre, parallel group design, open-label trial comparing cyclophosphamide, thalidomide, len, carfilzomib and bortezomib induction combinations and len maintenance treatment in TE and TNE patients. TE patients received high dose melphalan supported by autologous stem cell transplantation (ASCT). Patients in both pathways were randomised to maintenance with len or observation. In total, 4358 patients entered. Planned SPM analysis was conducted in May 2019, with 318 patients developing an SPM prior to that point. Median follow-up from trial entry was 60 months (IQ range 47-76). A nested cohort analysis was performed to determine EBV infection and immunity status in 170 SPM patients for which serum samples were available. Forty-two trial patients who did not develop an SPM were used as a control group. EBV assessment time-points included pre-induction, post induction, 4 months post ASCT (TE only) and 1 year post induction. Peripheral blood serum samples were tested for EBV EBNA IgG Antibody/index (LIAISON®), EBV VCA IgM Antibody/Index (LIAISON®) and EBV positivity was determined using the artus® EBV RG PCR Kit from Qiagen. Active or recent EBV infection was evidenced by a positive EBV IgM antibody and/or EBV PCR. Results Of the 170 patients, 208 SPM were noted with 147 patients developing 1 SPM and 23 patients developing ≥2. One hundred and five patients developed an SPM following maintenance randomisation, with 76 receiving len and 29 being observed. The remaining 65 patients developed an SPM prior to maintenance. Eighty-four SPMs were diagnosed in 68 TE patients and 124 SPMs in 102 TNE patients. Of the 170 SPM patients, 8 had evidence of recent or active infection at the time of testing, evidenced by either IgM EBV antibodies (n=5), positive EBV PCR (n=2) or both (n=1). The median EBV DNA copies/ml was 353 (range 337-428). The median IgM antibody titre was 71.5U/ml (26 - &amp;gt;160). No patients in the control group had evidence of recent EBV infection (p=0.36). Of the 8 patients with evidence of EBV infection, 6 developed &amp;gt;1 SPM, Table 1. Five had been treated in the TE pathway, with all developing post maintenance randomisation, and 4 of the 5 receiving len maintenance. None of the 3 TNE patients received len maintenance, with 2 developing an SPM prior to maintenance randomisation. The median time from EBV testing to SPM diagnosis was 17·9 months (0.5-51.7). Two of the EBV positive patients developed a haematological SPM: myelodysplastic syndrome and Hodgkin lymphoma. Four patients developed a solid malignancy: lung, breast, ovary, and colon. The remaining cases were non-melanoma skin cancers, Table 1. Immune status (EBV IgG) was also determined. In TE patients, the median EBV IgG titre was 65.3U/ml at diagnosis (&amp;lt;3 - 600, n=48), falling to 28.1U/ml following induction (&amp;lt;3 - 326, n=41) and recovering to 44.2U/ml one year post ASCT (&amp;lt;3 - 600, n=22). In TNE patients, the median IgG titre at diagnosis was 39.1U/ml (&amp;lt;3 to 517, n=72), falling to 31.2U/ml 4 months post induction (&amp;lt;3 - 287, n=42) and recovering to 51.3U/ml after 1 year (&amp;lt;3 - 554, n=41). In the SPM patients the IgG EBV titres were noted to be &amp;lt;20U/ml in 5 of the 8 patients. Three of the eight patients had no detectable EBV IgG level (&amp;lt;3U/ml) Conclusions These data suggest that EBV infection is unlikely to be a risk factor for SPM development in myeloma patients. This is supported by the finding that EBV IgG titres were consistent with immunity in most patients (&amp;gt;20U/ml) and even in the patients with possible EBV infection, EBV DNA was only identified in 3 patients, and at a low level. In addition, the SPM developed are not classically associated with EBV infection or reactivation. It is noted that EBV infection status was not always determined at the time of SPM development. Despite this, the data does show that EBV immunity recovers following therapy, even in the post ASCT setting. EBV monitoring is therefore not supported by this work, although in patients who develop ≥2 SPM, further clarification is required.

Ten Years of Hematopoietic Stem Cell Transplantation in Patients with Light Chain Amyloidosis: Real World Data from a Health Center in Latin America

Background: Autologous stem cell transplantation (ASCT) is an effective treatment for patients with AL amyloidosis. In recent years, due to the advent of daratumumab-based regimens that achieve fast, deep, and long-lasting hematological responses, the role of ASCT and its optimal timing have been put in discussion. Access to ASCT in Latin America is difficult and specialized transplant centers are scarce, as is access to daratumumab-based chemotherapy regimens. Objectives: To describe the characteristics and evolution of patients with AL amyloidosis who received an autologous stem cell transplantation (ASCT) estimating organic response, overall and progression-free survival. To compare the evolution between patients initially eligible for transplantation and those who were not. Methods: We designed a retrospective cohort study of adult patients with AL Amyloidosis who received an ASCT between 2012 and 2022. Those who did not complete one year of follow-up were excluded. We obtained data from patients enrolled in the Institutional Amyloidosis Registry. Continuous variables were compared with the Student or Mann-Whitney test according to distribution, and categorical variables were compared with chi2 or Fisher. Overall and progression-free survival was estimated using Kaplan Meier. Results: Of 129 patients with AL, 32 received ASCT (24.5%). Twenty were eligible for analysis.The baseline characteristics are shown in table 1. The median time to diagnosis was 14 months (IQR 7-27). At the time of diagnosis, 9 patients (45%) were not eligible for transplantation; in all cases, ineligibility was due to cardiac involvement, with 4 receiving heart transplantation prior to ASCT. The longest time between heart transplantation and ASCT was 348 days. More information on renal and cardiac involvement at diagnosis and at ASCT is shown on table 2. Regarding treatment, 18 patients underwent a single line of chemotherapy with a median of 4 cycles prior to ASCT. All patients received regimens with bortezomib and only 3 added daratumumab. One patient underwent ASCT without hematological response, 7 with a partial response (PR), 5 with very good partial response (VGPR) and 7 with a complete response (CR). The time to best hematological response was not statistically different between patients who did and did not receive daratumumab, probably due to the low number of patients in the daratumumab group. The median age at transplant was 63.5 years old (IQR 50.5-68). Fourteen patients underwent conditioning with full dose melphalan and 6 with reduced dose. There was no statistically significant difference between these groups in terms of relapse and survival. The median number of days of hospitalization for the transplant was 20 (IQR 18-24). Only two patients required intensive care. The median number of transfusions per patient was 5 (IQR 3-9). There were no deaths during hospitalization or in the first 100 days of followup. The median time to engraftment was 12.5 days (IQR 11-14); in patients with cd34 collects &amp;gt; 6.5x10(6), median time to engraftment was 12.2 days (IQR 10.6-13.8), and in patients with cd34&amp;lt; 6.5x10(6), 15.4 days (IQR 9.9-20.9). This difference, as well as the difference in transfusions among the two groups, was not statistically significant. After ASCT, 15 patients obtained CR and 5 VGPR; 8 patients relapsed. The median time to relapse was 6.10 years (IQR 2.28-6.70). Of 9 patients with renal involvement, 7 presented renal response (2 pre and 5 post ASCT). Of the remaining, 1 received a post ASCT kidney transplant. Median time to renal response from start of treatment was 740 days (IQ 400-1736). Amongst the 10 patients with cardiac involvement, 4 underwent pre-ASCT heart transplantation. Of the remaining, 5 (83%) documented cardiac responses with a median of 538 days (IQR 487-611), in 2 cases prior to ASCT. There were no differences in morbidity and mortality between heart transplant recipients and the ones who did not receive a heart transplantation. Only 3 patients died, 2 from causes related to cardiac involvement and one from unrelated causes. Conclusions: ASCT is a safe treatment when performed in an experienced center. It ensures deep responses and prolongs progression-free survival. Patient selection is key to achieve these outcomes. Ineligibility at diagnosis is not related to worse post ASCT morbidity and mortality outcomes. Heart transplantation prior to ASCT is a safe strategy to favor eligibility.

Spatial Mapping of Myeloma Bone Marrow Microenvironment Using a Deep Learning Approach

Background: Interactions between multiple myeloma (MM) cells and the bone marrow (BM) microenvironment influence disease evolution and drug resistance. Information is largely based on BM aspirates, which lack topological information and can be affected by haemodilution. To examine the spatial relationships between tumour and immune cells in the MM immune tumour microenvironment (iTME), we used multiplex immunohistochemistry (MIHC) coupled with deep learning (DL) image analysis for detailed visualization and unbiased automated analysis of BM components. Methods: BM trephines from patients (at a single centre) with monoclonal gammopathies of undetermined significance (n=9, MGUS) and newly diagnosed MM (n=10, NDMM) with paired baseline and day100 post autologous stem cell transplantation (ASCT) were stained with MIHC panels (BLIMP-1 for tumour, CD4, CD8, FOXP3). To dissect the unique BM landscape, we developed a superpixel based DL model (MoSaicNet) to distinguish blood, bone, fat and cellular tissue. We then developed a cell abundance aware DL method for cell detection and classification (AwareNet) on whole slide images. To tackle cell abundance bias, AwareNet assigned higher attention scores to rare cell types during model training. We used an independent validation cohort consisting of 9 NDMM with paired baseline and post-treatment BM samples to further evaluate the model's performance (n=18). Validation cohort samples were obtained from 7 different hospitals and were stained using a different autostainer of the same model. A colour normalization step was added before analysis. Results: MoSaicNet and AwareNet enabled us to evaluate densities and spatial proximity between cell types. To train, validate and test MoSaicNet, 269 regions of interest (69884 superpixels) from 19 BM samples were annotated by pathologists. For AwareNet, 8004 single-cell annotations were made on 11 samples. MoSaicNet achieved an overall classification area under the curve (AUC) of 0.99, 95% confidence interval (CI) [0.989, 0.991]. Similarly, AwareNet achieved a high overall AUC of 0.98 [0.977, 0.984]. AwareNet outperformed state of the art methods such as U-net and CONCORDe-Net in detecting both abundant and rare cell types. In addition, both algorithms achieved an overall AUC of &amp;gt;0.97 when applied to the validation cohort, despite different tissue processing and staining methods. Densities of FOXP3+CD4+, FOXP3-CD4+ and CD8+ cells did not differ significantly between NDMM and MGUS samples (p=0.32, p=0.81 and p=0.74 respectively), however, there were fewer BLIMP1+ cells in proximity to CD8+ cells in MGUS samples compared with NDMM samples. In NDMM patients, post-treatment samples revealed a reduction in densities of BLIMP1+ cells (p=0.013), CD8+ T cells (p=0.004) and FOXP3+CD4+ regulatory T cells (p=0.004) when compared with baseline. The number of BLIMP1+ cells in proximity to CD8+ and CD4+ cells significantly reduced post-treatment (Corrected for densities, p&amp;lt;0.05), indicating changes in iTME. Analysis of the validation cohort provided similar density and spatial results. Conclusion: We describe the use of a DL pipeline for tissue segmentation and automated cell annotation, enabling spatial mapping of the MM iTME to address topographical questions related to immune function and cell-to-cell interactions. The high accuracy in the validation cohort suggests that our model could be applied to other independent datasets after a normalization step.

High Progression Free Survival Rates in Patients with Multiply Relapsed/Refractory Hodgkin Lymphoma Undergoing Autologous Stem Cell Transplant after Checkpoint Inhibitors: Results from Grupo Argentino De Trasplante De Medula Osea y Terapia Celular (GATMO-TC)

CONCLUSIONS Consolidation with autologous stem cell transplant (ASCT) in Hodgkin lymphoma (HL) was traditionally reserved for patients with chemosensitive disease. In 2021 a retrospective study showed encouraging results with ASCT consolidation after checkpoint inhibitors (CPI) in pts with relapsed/refractory (R/R) HL. Subsequently, several prospective studies with CPI +/- chemotherapy in 2nd line were published showing 1-year progression free survival (1-y PFS) rates of 90% but with increased incidence of engrafment syndrome. We aimed to evaluate survival outcomes of consolidation with ASCT after CPI in our cohort of patients with R/R HL and the incidence of engrafment syndrome. Patients with R/R HL who received consolidation with ASCT between 01/2016 and 5/2023 after treatment with CPI were included in this retrospective multicentric study. Descriptive statistics were used to summarize variables of interest. Progression free (PFS) and overall survival (OS) were estimated with Kaplan-Meier and variables were compared with log-rank test. Forty-one patients from 15 transplant centers in Argentina were analyzed. The median age at ASCT was 31 years (19-60). High risk features were present in three quarters of patients, 23 (56%) with primary refractory disease and 8 (19.5%) with early relapse. Eighteen patients (43.9%) had ≥3 of the 5 pre-ASCT modified AETHERA high-risk factors. Patients received a median of 4 (2-6) systemic therapies before ASCT, including 27 patients previously treated with Brentuximab Vedotin (BV) to which 26 were refractory. Thirty-six patients (87.8%) received CPI monotherapy and 5 (12.2%) in combination with chemotherapy. Thirty-six (87.8%) underwent ASCT after CPI and 5 received additional treatment before transplant due to lack of response or progression. Patients received a median of 7 cycles (2-34) of CPI before ASCT. Complete metabolic (CMR) and partial remission (PMR) pre ASCT was documented in 31 (75.6%) and 10 (24.4%) patients, respectively). The median time from last dose of a CPI to ASCT was 60 days (3-183). The most utilized conditioning regimens were BEAM (22%), BEC (22%), BeEAM (7.2%) and CBV (48.8%). Median time to neutrophil engrafment was 11 days (8-15). Engrafment syndrome was observed in 14 (34.1%) with 10 patients requiring treatment with corticosteroids. Seven patients (17.1%) received post ASCT consolidation with either CPI or BV. After a median post ASCT follow up of 12.3 months, only 2 patients relapsed and 3 patients died (one of progressive disease, one of transplant related mortality and the other of a late infectious complication). Estimated 1-y PFS was 92.6% for the whole cohort, 93.5% and 90% for patients undergoing ASCT in CMR and in PMR, respectively, p: 0.92 (Figure 1). Patients requiring additional treatment after CPI had an estimated 1-y PFS of 80% vs. 94.4% in those undergoing ASCT straight after CPI, p: 0.38. ASCT consolidation after CPI in this cohort of patients with high risk R/R HL was associated with very promising results even in those proceeding to ASCT in PMR. A third of the patients developed engrafment syndrome so it is important to be alert to the appearance of symptoms and evaluate early use of corticosteroids. Our findings are similar to the results of other studies and support ASCT consolidation in high-risk R/R HL patients receiving CPI.

Post-Transplant Nivolumab Plus Unselected Autologous Lymphocytes in Truly Refractory Hodgkin Lymphoma Patients Is Highly Effective and Responses Are Mediated By NK Cells

Background In the relapsed/refractory Hodgkin Lymphoma (HL) setting (RHL), the achievement of complete remission (CR) is fundamental in order to proceed with allogeneic stem cell transplantation (HSCT) consolidation. Immune checkpoint inhibitors (CI) have demonstrated clinical activity in patients relapsing after ASCT, although only 20% CR rate is observed. In order to improve the efficacy of CI in RHL, we previously reported a salvage treatment based on early CI therapy following post-autologous stem cell transplantation (ASCT) with the reinfusion of unselected autologous lymphocytes infusions (ALI). The rationale of this approach is based on the achievement of a disease debulking through ASCT conditioning. Early administration of CI (nivolumab) is performed on a minimal disease burden, while reinfusions of ALI reduce post ASCT immune depression eliciting CI efficacy. Aims The aim of this study was to evaluate the efficacy of the procedure in terms of CR rates and overall survival (OS) after an extended follow up. Biological endpoint was to investigate the lymphocyte subpopulations involved in the mechanism of response and investigate the role of NK-cells mediating anti tumor responses in HL. Methods Patient were eligible to this study after failure to respond to first line treatment (i.e. positive PET2 or PET6 scan) and underwent autologous lymphocyte apheresis upon enrollment. All patients received conventional 2nd line chemo followed by 3rd line chemo-immunotherapy with Brentuximab-Vedotin (BV) in non-responding patients. Patient failing to achieve CR after BV were enrolled in the treatment arm and proceeded to ASCT + CI and ALI, whereas patients responding to 2nd- or 3rd treatment received ASCT followed by ALI alone, as a control cohort (figure 1A). NK cell degranulation assay was evaluated by staining for CD107a (LAMP-1) expression on healthy-donors derived NK cells exposed to HL cell lines (L428 and L250), in the presence or absence of monoclonal antibodies targeting inhibitory or activating receptors. Surface and intracellular staining was performed prior to flow cytometry and analysis was performed on the CD3-/CD56+ gated population. Results Twenty-one patients with RHL (median age 32 years; range 18-65) underwent lymphocyte apheresis after failure of 1st line chemo and then proceeded to salvage therapy. Thirteen patients failed to respond to 2nd and 3rd line therapy and thus received early post-transplant CI supported with four ALI. Eight patients responded to 2nd line chemo (n=6) or 3rd line BV (n=2) and received ASCT followed by ALI alone. No adverse events were recorded, specifically, no immune-related toxicity was observed. All patients receiving ALI + CI (treated patients) achieved negative PET scan CR. Eight of them received HSCT consolidation. One patient refusing HSCT after achieving CR in this study relapsed and responded to CI re treatment followed by HSCT. All patients in the treatment arm are alive and disease-free after a median follow-up of 32 months (95% CI 26.4-51.0). Median disease-free survival (DFS) was not reached in treatment arm (Fig 1B). Four of the patients in the control arm relapsed (50%). Three of them responded to 3rd line therapy and proceeded to HSCT. One patient achieved CR with conventional CI treatment but refused HSCT and the other relapsing patient died because of progressive lymphoma after failure to achieve CR with conventional single agent CI. Median DFS in the control arm was 22 months (Fig 1B). NK cells showed higher expansion and a faster maturation in the treatment arm, compared to the control arm (p&amp;lt;0.05). As expected, HL cells lines do not express HLA class I and II, but express activating NK cells receptors (aNKG2D, aNKp30, aNKp46, aDNAM-1). In vitro, the activation of each of those receptors was able to trigger NK cells degranulation. Similarly, PD-L1 and PD-L2 blockade on HL cell lines significantly increased NK cell degranulation (p&amp;lt;0.05). Taken together, those observations support the role of NK cells in this setting. Conclusions Our data show very high anti-tumor activity of ALI + CI for RHL, allowing most patients to proceed to HSCT. RHL patients in the treatment arm had an excellent outcome if compared to the control arm, which included patient who did respond to conventional treatment. Biological data suggests that this approach may accelerate NK cell development/maturation and suggest that NK cells may mediate response to CI in HL.

RAMP up: Risk Adapted Post-Autologous Transplant Maintenance Therapy in MRD Positive Myeloma Patients

Background. Post-autologous stem cell transplant (ASCT) maintenance therapy for patients with newly diagnosed multiple myeloma (MM) continues to evolve. Currently, single agent lenalidomide maintenance remains standard of care but outcomes for patients with high-risk cytogenetics are inferior to those with standard risk disease; optimal maintenance strategies for these patients need to be developed. Minimal residual disease (MRD) has proven to be a powerful prognostic factor for PFS and OS but is not yet used to guide treatment. Isatuximab is a cytolytic CD38-directed, immunoglobulin G1 (IgG1) chimeric monoclonal antibody FDA-approved for the treatment of relapsed or refractory MM that is overall well tolerated and efficacious when used in combination regimens. Our upcoming trial, RAMP UP (NCT05344833), investigates the safety and efficacy of isatuximab combined with lenalidomide as a maintenance regimen in patients who are MRD-positive after autologous transplant. Study Design and Methods. This prospective, multicenter single-arm phase 2 (Figure 1) trial will enroll patients that are MRD-positive (10 -5) by Adaptive next generation sequencing within 90 days (+/- 30 days) post-autologous transplant. We plan to enroll: R-ISS stage 1, 2 or 3; &amp;lt;2 lines of induction therapy prior to transplant; &amp;gt; PR per IMWG criteria post-transplant; and ECOG Performance Status &amp;lt;2. Patients will be treated with isatuximab (10 mg/kg weekly for cycle 1 and every other week thereafter) and lenalidomide (10 mg daily on days 1-21) on 28-day cycles for a total of 3 years. Patients will be monitored for disease response every 3 months and for marrow MRD every 12 months. The primary endpoint is the 1-year rate of CR/MRD negativity (10 -5); secondary endpoints include 1-year rate of CR/MRD negativity (10 -6), IMWG-defined response rates, 3-year overall CR/MRD-negativity, PFS, OS, treatment-related adverse events, and health related quality of life (HRQoL) measured by EORTC-QLQ-C30, EQ-5D-5L, EORTC QLQ-MY20. We propose enrollment of 50 patients to allow for approximately 10% dropout rate in order to have 43 patients analyzed for the primary endpoint; for 50 patients to be treated, we estimate that 75-100 patients may have to be enrolled. Correlative objectives include correlation of isatuximab pharmacokinetics and receptor occupancy with MRD-negative response and time to progression, characterization of differences in the BM and peripheral blood T, B, and myeloid cell compartments using cellular indexing of transcriptomes and epitopes (CITE-Seq) between responders and nonresponders, and concurrent assessment of other disease biomarkers, including peripheral blood circulating multiple myeloma cells (CELLSEARCH), with MRD testing. Discussion. Our study started June 2023. One patient has been enrolled, and two have signed informed consent for enrollment. Ultimately, our study aims to inform MRD risk-adapted approaches for maintenance therapy in myeloma.

Disease Characteristics and Outcomes of 504 Young Patients Diagnosed with Multiple Myeloma Treated with Modern Therapies in Canada

Background:Multiple myeloma (MM) mostly affects older adults. Although representing around 10% of all cases, patients ≤ 50 years old suffer from the highest number of years lost due to their disease. MM in young patients occurs during their most productive years of life, resulting in a significantly higher personal, familial, professional, and economic burden. Young MM patients are currently underrepresented in clinical trials due to small numbers overshadowed in cohorts of older patients. Their disease characteristics and outcomes following modern treatments remain poorly understood (Tanguay M et al., Current Oncol 2023). The purpose of this study is to report disease characteristics, treatments, and outcomes of young MM patients treated in Canada. Methods:This is a retrospective study using the Canadian Myeloma Research Group Database, which is a repository of real-world patient data reflecting 17 of the major MM academic centers across Canada. All patients 18-50 years old with newly diagnosed MM between January 1, 2010 and July 1, 2022 were included. High-risk (HR) cytogenetics were defined as either del17p, t(4;14) or t(14;16). Survival analyses were performed using the Kaplan-Meier method. Results:Among the 6,604 patients newly diagnosed with MM during the study period, 504 (7.6%) were aged between 18-50 years, and included in this analysis. Within this young group, 87 (17.3%) were 18-40 years old and 417 (82.7%) were between 41-50 years. MM was diagnosed in 301 (59.7%) patients between 2010 to 2015, and in 203 (40.3%) patients between 2016 to 2022. The median age at diagnosis was 45.9 years (range 25.6 to 50). Male patients represented 57.7% of the cohort. IgG was the most common isotype in 251 (49.8%) cases, while 115 (22.8%) patients had light chain disease. In 375 patients with available data, 16% were R-ISS 1, 73.1% R-ISS 2, and 10.9% R-ISS 3. Lytic lesions, elevated creatinine, anemia, hypercalcemia, and high LDH were respectively present in 46.8%, 15.5%, 44%, 18.8%, and 18.7% of patients. HR cytogenetics were present in 23.7% of patients, with del17p in 11.5%, t(4;14) in 14.9%, and t(14;16) in 5.1%; while 1q+ and del1p were detected in 27.9% and 15.3%, respectively. Twelve (2.4%) patients were diagnosed with plasma cell leukemia. First-line treatment was proteasome inhibitor (PI)-based in 462 (91.7 %) and immunomodulatory (IMiD) agent-based in 7 (1.4 %); 18 (3.6%) received both a PI and an IMiD and 17 (3.4%) were treated with other modalities. Among all patients, 453 (89.9%) underwent autologous stem cell transplant (ASCT) during their disease course. Some patients did not receive ASCT for the following reasons: early death before ASCT in 10 (2%) cases, lost to follow-up prior to ASCT in 13 (2.6%) cases, deemed ineligible for ASCT or patient declined in 24 (4.8%) cases, and participation in a clinical trial not involving ASCT in 1 (0.2%) case. Out of the entire cohort, allogeneic-SCT (allo-SCT) was performed in only 11 patients (2.2%), including 3 (0.6%) who received allo-SCT alone without ASCT. Among patients who received maintenance post ASCT, 93.6% were treated with a lenalidomide-based regimen. Median duration of the different maintenance treatments was 21.2 months. With a median follow-up of 51.9 months (range 0.9 to 154), median PFS (progression-free survival) was 55.4 months (95% CI 49.1-70.2), while median OS (overall survival) was not reached. The 5-year OS and PFS were 78% (95% CI 74-82) and 48% (95% CI 43-53), respectively, whereas the 10-year OS and PFS were 64% (95% CI 58-71) and 28% (95% CI 22-35), respectively (Figure 1a). Median PFS for patients with any HR cytogenetics was 37.9 months (95% CI 29.6-62.8) vs 64.5 months (95% CI 50.6-80.7) for patients with standard-risk cytogenetics (p=0.004) (Figure 1b). We observed no difference in disease characteristics, treatments, and outcomes after comparing cohorts aged 18-40 years old vs 41-50 years old. Conclusions: This is among the largest real-world cohorts of young MM patients ≤ 50 years old treated with modern therapies ever reported. Most patients were R-ISS 2 (73.1%), 23.7% had known HR cytogenetics, and the majority (91.7%) received a PI-based first-line treatment. Outcomes of specific subgroups are under analysis and will be presented. Although the OS was not yet reached in this young population, the median PFS of only 55.4 months highlights the urgent need to develop more effective treatments to induce deeper and more durable responses.

The Peripheral Blood Stem Cell Immunome Demonstrates Abnormal Immune Effector Cells Early in the Disease Course of Multiple Myeloma and Contributes to Inferior Outcomes and Secondary Myeloid Neoplasms

Background: Upfront autologous stem cell transplant (ASCT) is the standard-of-care for newly diagnosed multiple myeloma (MM) patients. However, relapse and the development of therapy-related myeloid neoplasms (t-MN) post ASCT results in considerable morbidity and mortality. We hypothesized that enrichment of abnormal myeloid progenitors and immune effector cells (IEC) in peripheral blood stem cells (PBSCs) of patients with MM is associated with a higher risk of relapse and development of t-MN. Methods: After institutional review board approval, we screened patients with active MM that were evaluated at Mayo Clinic, Rochester, MN between 01/01/2003 and 12/31/2020. Patients that underwent an ASCT and had cryopreserved PBSC product available for research were included. Using mass cytometry, we performed a comprehensive immunophenotyping of mobilized cryopreserved PBSCs from 54 MM patients undergoing 1 st ASCT, using validated antibody panel of 37 lymphoid- and myeloid-based markers each. Flow cytometry standard files were normalized and concatenated using the Fluidigm acquisition software. Flow cytometry standard files were uploaded to the OMIQ software from Dotmatics (www.omiq.ai, www.dotmatics.com), where transformation and cleaning (doublets, debris) were performed. To correct for between-sample technical variations (“batch effects”), we used fdaNorm within the omiq.ai platform. Clustering and visualization of normalized and concatenaded flowcytometry files were performed within the omiq.ai platform using PhenoGraph and UMAP, respectively. We performed principal component analysis (PCA) to identify major immunomic drivers of variability across patients. We explored the associations between immune subsets and the dichotomized clinical outcomes of interest: progression-free (PFS), myeloid neoplasm-free (MNFS) and overall survival (OS) from ASCT. A 2-sided false discovery rate adjusted P-value of &amp;lt;0.05 was considered significant when multiple comparisons were performed; otherwise, a P-value of &amp;lt;0.05 was considered significant. Results: The most abundant cell populations were T-cells (49% of the CD45 +) and myeloid cells (43% of the CD45 + cells). Clustering on the CD45 + cells revealed 30 unique lymphoid clusters and 27 unique myeloid clusters. Subclustering on NK-cells identified an additional 16 NK-cell clusters. On PCA, principal components-1 (PC-1) and 2 (PC-2) explained 15.2% and 12.5% of the variability in the data, respectively. A high PC-2 score was associated with inferior median PFS (20 vs. 52 months; P=0.005, Figure 1A), MNFS (52 vs. 85 months, P=0.03, Figure 1B) and OS (64 vs. 106 months, P=0.01) from ASCT. Immune subsets enriched in the high PC-2 cohort included the ‘NKT-like’ (CD56 +) T-cell subset which expressed the inhibitory CD159a receptor and TIGIT; a terminally differentiated (CD27/CD28 -, CD57/KLRG1 +) and exhausted (TIGIT/PD-1 +) T cell subset, 2 exhausted (TIGIT/PD-1 +) T cell subsets; an immunosenescent (CD27/CD28 -, CD57/KLRG1 +) T cell subset as well as a terminally exhausted (C27/C28 -, KLRG1/PD-1/TIGIT +) TCRgamma-delta subset. Immune subsets with high loadings within PC-1 (associated with improved clinical outcomes) consisted exclusively of CD4 + cells with early memory phenotypes (CD27/CD28/CD127 +). Abnormal expression of CD7 and HLA-DR expression on myeloid progenitor cell subsets was associated with an inferior PFS, MNFS, and OS. A NK-cell subcluster, characterized by an immature (CD56 high), inhibitory (CD159a +, NKG2A) phenotype, was enriched in patients developing t-MN (0.33% vs. 0.17%, P=0.006). Conclusion: We identify abnormal myeloid and immune effector cells in the PBSCs of patients with MM, even prior to ASCT. Patients with a PBSC product that is enriched in immunosuppressive T and myeloid cell subsets, and with a lower proportion of antigen presenting cells, progenitor populations, and anti-tumor macrophages have a shorter PFS and MNFS. This suggests that the predisposition to t-MN and inferior outcomes for MM are possibly determined early in the disease course. These findings need external validation and have the potential to guide sequencing of future treatment modalities.

Real-World Treatment Patterns and Patient Outcomes in Relapsed/Refractory Hodgkin Lymphoma in the US

Introduction Brentuximab vedotin (BV), a CD30-directed monoclonal antibody, and programmed cell death-1 inhibitors (PD-1; e.g., nivolumab, pembrolizumab) are efficacious for the treatment of adult patients with Hodgkin lymphoma (HL) at high risk of relapse or progression post-autologous stem cell transplantation (ASCT). In this study, we investigated the real-world treatment patterns and outcomes of patients with relapsed/refractory HL (RRHL) who had received ≥1 line of therapy (LOT). Methods Patients ≥18 years old with evidence of RRHL in ≥1 inpatient or ≥2 outpatient physician medical notes or evidence of ≥1 autologous/allogeneic hematopoietic stem cell transplant (HSCT) procedure following evidence of HL in the Humedica Electronic Medical Record (EMR) database, were selected between October 1, 2016 and September 30, 2020. The earliest evidence of RRHL (medical note or HSCT procedure) was defined as the patient's index date. Patients were excluded if they had evidence of RRHL, non-Hodgkin's disease, other primary cancers, or metastatic disease in the 12 months prior to the index date (baseline period). Patient demographic and clinical characteristics were evaluated during the baseline period and the index date. Patients were followed from their index date until patient death or the end of recorded healthcare activity during which treatment patterns and outcomes were assessed. Results A total of 342 patients with ≥1 LOT post-RRHL during the follow-up period were included in the final study population. Mean age was 44.2 years, 56.7% were male, 75.7% were white, and 61.4% had commercial insurance; mean Charlson Comorbidity Index score was 3.2 (Table 1). Approximately one-third (34.5%) of patients were not eligible for HSCT based on available laboratory data and comorbidity diagnoses during the baseline period or the index date. Across the study population, the average follow-up duration was 25.6 months (median: 23.9 months). Among the overall study population, 90 (26.3%) patients received BV treatment, with most (~86%) receiving BV in LOTs 1 and 2 post-RRHL evidence (Table 2). The average time from index date to initiation of BV treatment was 2.5 months and mean duration of treatment (DOT) with BV was 4.3 months. Most patients treated with BV (n=68) had not received a HSCT. During the follow-up, among those who received BV but not a PD-1 (n=57), the progression-free survival (PFS) rate was 73.7% and overall survival (OS) was 82.5%. Among the overall study population, 56 (16.4%) patients received a PD-1, with most patients (~68%) receiving a PD-1 in LOTs 1 and 2 post-RRHL evidence. The average time from index date to initiation of PD-1 treatment was 5.5 months and mean DOT with a PD-1 was 5.3 months. Among those patients who received a PD-1 but not BV (n=23), the PFS rate was 56.5% and OS was 69.6%. One patient received post-HSCT BV+PD-1 combination maintenance therapy. Among the patients who received BV and/or a PD-1 prior- or post-HSCT, 12 (52.2%) received BV prior to the HSCT and 9 (39.1%) received BV after the HSCT. Among those who received BV and PD-1 treatments (i.e., not at the same time; n=33), the PFS rate was 60.6% and OS was 90.9%. Among the study population, a majority of patients (n=232; 67.8%) did not receive a HSCT during the follow-up period (including the index date). Of these patients without a HSCT, 68 (29.3%) received BV, 46 (19.8%) received a PD-1, and 25 (10.8%) received both BV and a PD-1 (i.e., not at the same time). Conclusions In this real-world evaluation of the treatment patterns and outcomes among patients in post-RRHL evidence setting, BV was administered more frequently in patients without HSCT. Increasing the use of BV in patients with ASCT at high risk for relapse or progression may lead to improved clinical outcomes. This study was based on EMRs from a single administrative database and has a limited sample size; these findings may not apply to all patient populations in post-RRHL evidence setting in the US.

A Personalized Whole Genome-Informed Assay Targeting Single Mutant in Circulating Tumor DNA Can Identify MRD and Predict Relapse in DLBCL

Introduction: Minimal residual disease (MRD) detected by circulating tumor DNA (ctDNA) has emerged as a promising biomarker in diffuse large B-cell lymphoma (DLBCL). MAESTRO (minor-allele-enriched sequencing through recognition oligonucleotides) was recently developed to aid the detection of low-frequency mutations by enriching for mutant alleles using probes preferentially capturing single-nucleotide variants. We have extended this application - termed MAESTRO-Pool - to analyze personalized MRD variant detection within a cohort-level single assay. We demonstrate high sensitivity to detect MRD using MAESTRO-Pool and the detection of emergent mutations using targeted sequencing of the same samples. Methods: Fifty-nine plasma specimens from 9 patients with relapsed/refractory (R/R) DLBCL treated on a phase II trial (NCT02362997) of post-autologous stem cell transplant (ASCT) pembrolizumab maintenance were tested. Cases were selected based on the availability of genomic DNA from tumor tissue, patient-matched germline DNA, and serial post-ASCT plasma samples (≥ 3 time points). MAESTRO probes were designed to target patient tumor-specific somatic variants using results of baseline tumor-normal whole genome sequencing. Probes were then pooled into an integrated, cohort-level assay (MAESTRO-Pool). Serial samples were compared with an orthogonal, whole-genome, tumor-informed MRD test which does not use mutation enrichment (MRD Tracker; Parsons, HA et al. Clin Cancer Res26, 2556-2564 (2020)) for sensitivity and specificity of variant detection. In addition, sensitivity to detect MRD and predict relapse was compared to that observed with immunoglobulin locus high-throughput sequencing (IgHTS). Additional baits were designed to capture single nucleotide variants (SNVs) previously reported in R/R DLBCL (63 loci in 12 genes), enabling detection of treatment-emergent mutations not identified in baseline tumor specimens. Results: Tumor-normal WGS revealed a median of 433 somatic SNVs per tumor (range 81-1653). The pooled assay comprised 6044 SNV-specific probes. MRD identification was similar for MAESTRO-Pool and MRD Tracker. Among 59 samples, a discrepant MRD call was observed for a single sample where ctDNA was detected at 4 ppm using MRD Tracker, but not detected using MAESTRO-Pool (limit of detection [LoD] 16 ppm). Estimated tumor fractions using MRD Tracker and MAESTRO-Pool were concordant. Even with reduced sequencing requirements of MAESTRO-Pool, we observed a similar median limit of detection (LoD) for MAESTRO-Pool (median 30 ppm, range 1-18,243) and MRD Tracker (median 40 ppm, range 1-4,727 ppm). MAESTRO-Pool identified ctDNA prior to recurrence for all 5 patients who relapsed, including at the earliest available post-ASCT timepoint for 4 of 5 relapsing patients. The time from ctDNA detection to clinical relapse (lead time) was the same or longer for each patient using MAESTRO-Pool (median 178 days, range 69-518) compared to IgHTS (median 44 days, range not detected to 518 days) (p=0.37) (Fig.1a). MAESTRO-POOL was associated with improved sensitivity compared to IgHTS (MAESTRO-Pool sensitivity of 90.5% for samples with matched IgHTS results versus IgHTS sensitivity of 61.9%, p=0.006). Superior sensitivity was primarily driven by MAESTRO-Pool's improved detection of low-frequency (&amp;lt;1000 ppm) mutant alleles. In addition to tracking molecular tumor burden, we identified several de novo mutations in relapsing patients using targeted sequencing of the same samples. Notably, plasma from a patient who progressed at 18.5 months post-ASCT (DL-015) manifested an emergent CREBBP R1446H mutation not detected in the baseline tumor whose allele frequency steadily increased from 0.048% one week after ASCT to 30.533% at relapse (Fig 1b). Conclusion: In this pilot study, MAESTRO-Pool enabled ultrasensitive detection and quantification of MRD with superior sensitivity compared to IgHTS. Complementary targeted sequencing also characterized genetic evolution, including detection of treatment-emergent mutations. Our results support the incorporation of ctDNA testing using MAESTRO-Pool in future prospective trials in DLBCL.

Blinatumomab consolidation post–autologous stem cell transplantation in patients with diffuse large B-cell lymphoma

AbstractOutcomes in patients with relapsed diffuse large B-cell lymphoma (DLBCL) who undergo autologous stem cell transplant (auto-SCT) are poor. Blinatumomab is a CD3/CD19 bispecific T-cell engager that directs cytotoxic T cells to CD19+ cells. Here, we performed a pilot study of blinatumomab consolidation after auto-SCT for 14 patients with DLBCL or transformed follicular lymphoma. All patients underwent standard-of-care auto-SCT with carmustine, etoposide, cytarabine, and melphalan (BEAM) conditioning followed by 1 cycle (4 weeks continuous infusion) of blinatumomab consolidation starting at day 42 after auto-SCT. All 14 patients treated on study completed BEAM auto-SCT and 1 cycle of posttransplant blinatumomab. Five patients developed grade 1 cytokine release syndrome (CRS), with no grade 2 or higher CRS. Immune effector cell–associated neurotoxicity syndrome was not observed. Patients were followed up for 3 years after auto-SCT, with median follow-up of 37 (range, 12-65) months. One-hundred days after auto-SCT (1 month after blinatumomab consolidation), 12 patients (86%) had achieved complete remission. At 1 year after auto-SCT, 7 patients (50%) remained in CR, and 1 patient had died of progressive disease. Patients who relapsed had a lower CD8:CD4 T-cell ratio before starting blinatumomab than patients who remained in remission. This pilot study demonstrates blinatumomab consolidation after auto-SCT is safe and well tolerated. Strategies to increase the CD8:CD4 ratio and use additional cycles of consolidation in a larger randomized trial are needed to confirm the efficacy of consolidation with blinatumomab after auto-SCT. This trial was registered at www.clinicaltrials.gov as #NCT03072771.

High Rates of Seroprotection and Seroconversion to Vaccine-Preventable Infections in the Early Post-Autologous Stem Cell Transplant Period.

In patients early post-autologous stem cell transplant, seroprotection rates were high for Hemophilus influenzae type B and tetanus toxoid (70%-90%) but lower for Streptococcus pneumoniae (30%-50%) including after revaccination. There were high rates of seropositivity (67%-86%) to measles, mumps, and rubella and varicella zoster virus. Durability of protection requires assessment.

Bortezomib and Vorinostat Therapy as Maintenance Therapy Post Autologous Transplant for Non-Hodgkin's Lymphoma Using R-BEAM or BEAM Transplant Conditioning Regimen.

The success of autologous stem cell transplantation (ASCT) for treating non-Hodgkin's lymphoma (NHL) is limited by its high relapse rates. To reduce the risk of relapse, additional maintenance therapy can be added post-transplant. In a non-transplant setting at the time of initiation of this study, both bortezomib and vorinostat had been studied alone or in combination for some NHL histology and showed some clinical activity. At our center, this combination therapy post-transplant for Multiple Myeloma (MM) showed acceptable toxicity. Therefore, it seemed reasonable to study this combination therapy post-ASCT for NHL. NHL patients underwent conditioning for ASCT with rituximab, carmustine, etoposide, cytarabine, melphalan (R-BEAM)/carmustine, etoposide, cytarabine, melphalan (BEAM). After recovery from the acute transplant-related toxicity, combination therapy with IV bortezomib and oral vorinostat (BV) was started and was given for a total of 12 (28-day) cycles. Nineteen patients received BV post ASCT. The most common toxicities were hematologic, gastrointestinal, metabolic, fatigue and peripheral neuropathy. With a median follow-up of 10.3 years, 11 patients (58%) are alive without disease progression and 12 patients (63%) are alive. BV can be given post-ASCT for NHL and produces excellent disease-free and overall survival rates.

Prognostic significance of extramedullary disease (EMD) detected on pre-transplant 18F-FDG PET/CT in patients with multiple myeloma: Results of PIPET-M trial

BackgroundIt is difficult to prognosticate the post-Autologous Stem Cell Transplant (ASCT) responses in multiple myeloma (MM) with the currently available prognostication models. 18F-FDGPET/CT has numerous advantages to prognosticate the post-transplant responses by assessing extramedullary disease (EMD) in addition to the extent of active disease. We aimed at identifying the prognostic value of EMD in predicting progression-free survival (PFS) and overall survival (OS). MethodsThis is a single centre prospective study from western India during a study period of 2014–2022 (with a median follow-up of patients of 6 years). All ASCT patients underwent 18F-FDG-PET/CT as part of pre-transplant workup. The conditioning and treatment protocols were not modified based on PET/CT findings. EMD on PET/CT was correlated with pre-transplant biochemical markers and post-ASCT survival/ progression (as defined by revised IMWG criteria). Statistical analysis was done using SPSS ver. 20. ResultsPatients with pre-ASCT EMD had a hazard-ratio for post-transplant all-cause mortality of 5.46 (p-0.045). Pre-transplant β2M and LDH were significantly higher in patients with EMD (p-0.036). The 6-year median OS in patients with and without EMD were 57.1%, and 80.6% respectively. Kaplan-Meier analysis showed poorer OS in patients with EMD χ2 (1–0.496, p-0.481). There was no significant difference in clinical or biochemical EFS among patients with EMD. ConclusionEMD detected on 18F-FDG-PET/CT has a higher hazard for mortality and is significantly correlated with pre-transplant higher β2M and LDH levels. Thus, EMD by pre-transplant 18F-FDG-PET/CT has a significant prognostic role.