Evaluating serum-free light chain ratio as a biomarker for multiple myeloma

8047

Background: In 2014, the definition of multiple myeloma was updated to include serum free light chain (FLC) ratio ≥100 as a myeloma defining biomarker, based on retrospective data indicating a 2-year progression rate of 80% and a median time to progression (TTP) of 12 months associated with this marker. However, two recent studies have reported lower 2-year progression rates, 30-44%, and longer median TTP of 40 months in patients with FLC ratio ≥100. Because of the disparity in risk prediction by FLC ratio across studies, we were motivated to assess the risk of progression in patients with SMM and a FLC ratio ≥100. Methods: We performed a retrospective analysis of patients diagnosed with SMM at Memorial Sloan Kettering Cancer Center between January 2000 and December 2017. Diagnosis of SMM and progression to MM was defined according to the International Myeloma Working Group (IMWG) criteria at the time of diagnosis. Kaplan-Meier method was used to assess TTP and generate survival curves, with log-rank test for comparison between groups. Results: A total of 438 patients were included in the study, with a median follow-up time of 52 months. While all patients with a FLC ratio ≥100 (n = 66) had elevated involved FLC levels, 35 (53%) had an involved FLC concentration > 100 mg/L. Per current diagnostic criteria, we only included patients with an involved FLC concentration > 100 mg/L in the FLC ratio ≥100 group, and found a median TTP of 31 months (95% confidence interval [CI] 16-59 months) and a 2-year progression rate of 49% (CI 28-63%). In a sensitivity analysis including all 66 cases with FLC ratio ≥100 (independent of involved FLC concentration), we found the median TTP to be 41 months (CI 30-72 months), compared to 101 months for those with a FLC ratio < 100 (CI 78-127 months; p < 0.0001). The risk of progression within 2 years was 35% (CI 22-46%) compared to 18% (CI 14-23%; p < 0.0001). Of note, 22 patients with a FLC ratio ≥100 were monitored expectantly for > 4 years, among whom 12 patients had an involved FLC level > 100 mg/L. Ten patients (7 with involved FLC level > 100 mg/L) were followed over a period ranging from 4 to 8.5 years before eventually progressing, and 12 patients (5 with involved FLC level > 100 mg/L) were followed between 4 and 8 years and did not progress during the study period. Conclusions: While FLC ratio ≥100 is associated with a high risk of progression in patients with SMM, it does not infer an imminent risk of progression, defined by the IMWG as median TTP of 12 months and 2-year progression rate of at least 80%. On the contrary, select patients with FLC ratio ≥100 can be followed for many years without progressing and some may never progress despite long-term follow-up. These findings suggest that in patients where FLC ratio ≥100 is the only myeloma-defining event, other high-risk features as well as the evolution of FLCs over time should be considered in the decision to start a patient on treatment.

Clinical efficacy of daratumumab (DARA)-based second line therapy after DARA-containing and DARA-free induction therapies in multiple myeloma: A single center experience

e20005

Background: DARA has been FDA approved for newly diagnosed multiple myeloma (NDMM) in combination with lenalidomide/dexamethasone (Rd), bortezomib/melphalan/dex, and bortezomib/thalidomide/dex since 2018. With the increase use of DARA combinations in NDMM, understanding the role of DARA retreatment at relapse needs to be examined in clinical practice. Herein, we describe a single institution experience of the efficacy of DARA-based retreatment as second line of therapy (LOT2) for patients (pts) who received DARA-based induction compared to DARA-free induction regimens. Methods: Thirty-three pts treated with DARA-based LOT2 at MSK from 1/2015 to 9/2021 were included in this retrospective analysis. Primary endpoint was overall response rate (ORR; ≥PR by IMWG criteria). Discrete patient characteristics were summarized by frequency (percentage) and continuous characteristics were summarized by median (IQR). Progression free survival (PFS) was evaluated by Kaplan-Meier method. Results: Two cohorts were identified based on prior DARA exposure: cohort 1 (N=6) received DARA-based induction without meeting DARA-refractory criteria and cohort 2 (N=27) had carfilzomib and Rd (KRd) induction (Table). Median follow-up was 13.8 and 14.5 months for cohorts 1 and 2, respectively. In cohort 1, 5 pts received DARA-KRd and 1 had DRd as first line therapy (LOT1). Median time between last dose of DARA in LOT1 and first dose of DARA in LOT2 was 17.5 months (IQR 12.1-19.8). ORR were 83% and 79% for cohorts 1 and 2, respectively. In cohort 1, ORR comprised of 1 sCR, 1 VGPR, and 3 PR. For cohort 2, there were 5 sCR/CR, 7 VGPR, and 9 PR. Median PFS was not reached in cohort 1 and 16.2 months in cohort 2. Conclusions: In a cohort of pts retreated with DARA after DARA-based induction, our findings suggest that DARA-exposed MM pts may derive benefit from DARA retreatment in subsequent lines of therapy similarly to pts who were DARA-naïve prior to DARA-based LOT2. Longer follow-up is needed to assess survival outcomes. In addition, larger confirmatory studies are warranted to further characterize response characteristics of DARA combinations in LOT2, especially as DARA-based therapy is increasingly used in treating NDMM. [Table: see text]

African American patients with smoldering multiple myeloma may have a lower risk of progression compared to White patients

8045

Background: The incidence of multiple myeloma (MM) is two to threefold higher in African Americans (AAs) compared to whites when adjusted for socioeconomics, age, and sex. However, there is limited information on whether racial background affects the risk of progression from smoldering MM (SMM) to MM. Methods: Patients with SMM presenting to Memorial Sloan Kettering Cancer Center between the years 2000 and 2019 and who identified as either AA or white were included in the study. Baseline characteristics were collected at the time of diagnosis including laboratory, imaging, and pathology reports. Differences in distributions of continuous and discrete characteristics were assessed by Kruskal-Wallis and chi-square tests. Time to progression (TTP) was assessed using the Kaplan-Meier method with log-rank test for comparisons. Univariate and multivariate Cox proportional hazard models were used to estimate effects of risk factors on TTP with hazard ratios (HR) and 95% confidence intervals (CI). Results: A total of 576 patients were included (70 were AA, 12%). Median follow-up time was 3 years in AAs and 4 years in whites. Differences in baseline characteristics between AAs and whites included median age (60 years in AAs vs 64 years in whites, p = 0.01), median hemoglobin level (12.3g/dL in AA vs 12.8g/dL in whites, p = 0.02), and immunoparesis including 1 or 2 uninvolved immunoglobulins (31% and 10% in AAs vs 56% and 27% in whites, p = 0.002). There was no difference in bone marrow plasma cells, M-spike, free light chain ratio, or Mayo-2018 SMM risk score. AA race was associated with a significantly decreased risk of progression in the univariate model (HR 0.57, CI 0.34-0.94). In the multivariate model adjusting for age, sex, and variables associated with an increased risk of progression in the univariate model (bone marrow plasma cells, M-spike, free light chain ratio, immunoparesis and low albumin), AA race remained associated with a decreased risk of progression (HR 0.39, CI 0.16-0.95). Overall, AA patients with SMM had a significantly (p = 0.027) longer median TTP (9.7 vs 6.2 years), and a lower 2-year (12.6% vs 20.1%) and 5-year (34% vs 44.6%) progression rate than whites. Because AA patients were younger at diagnosis, we stratified patients by age group, < 65 vs ≥65 years. In patients < 65 years, there was no difference in progression rate. In patients aged ≥65 years, AA patients continued to have a longer TTP than whites (9.8 vs 5.2 years, p = 0.02). Conclusions: In our retrospective single institution experience, AA patients with SMM had a lower risk of progression to MM compared to whites. Both groups had similar Mayo-2018 risk scores, however, AA patients had a lower degree of immunoparesis at baseline. Future studies are needed to better understand if these differences are explained by differences in disease biology including genomic mechanisms, immune microenvironment, and systemic immune response.

MASS-FIX versus standard methods to predict for PFS and OS among multiple myeloma patients participating on the STAMINA trial

8009

Background: Measuring response among patients with multiple myeloma is essential for the care of patients. Deeper responses have been associated with better progression free survival (PFS) and overall survival (OS). Serum (SIFE) and urine immunofixation are the currently used markers for biochemical documentation of CR after which marrow is tested for plasma cell clearance. Next generation flow cytometry and sequencing are used to document the presence of minimal residual disease (MRD). Mass spectrometry of blood by MALDI (Mass-Fix) is a new simple, inexpensive, sensitive, and specific means of detecting monoclonal immunoglobulins. To better test the hypothesis that Mass-Fix is superior to existing methodologies to predict for survival outcomes—especially SIFE-- samples from the STAMINA trial (NCT01109004), a trial comparing 3 transplant approaches among patients who have already received induction, were employed. Methods: Five-hundred and seventy-five patients were included. Samples from enrollment post-induction (post-I) and 1-year post enrollment (1YR) were tested when available. Four response parameters were assessed univariately: Mass-Fix, SIFE, complete response, and MRD by next generation flow cytometry. Mass spectrometry spectra were evaluated in a blinded fashion. Complete response was according to the 2006 International Myeloma Working Group criteria. Multivariate Cox proportional hazard models using stepwise regression were developed to explore the independent effect of the different response parameters on PFS and OS and interactions with other risk factors. Results: Of the 4 response measures, only MRD and Mass-Fix predicted for PFS and OS at multiple testing points on multivariate analyses (Table). Of the 4 post-I measurements, only MRD predicted for PFS; however, Mass-Fix was the only post-I measurement to predict for OS. Of all the 1-year measures, both 1YR Mass-Fix and 1YR MRD positivity predicted for inferior PFS and OS. In models including MRD and Mass-Fix, SIFE and CR were not prognostic for PFS or OS. Conclusions: Mass-Fix is a powerful means to track monoclonal proteins. The full utility of Mass-Fix was not exploited given the absence of a diagnostic sample and the fact that only serum (and not urine) was tested. Despite these limitations, it performed well at pre-induction and at 1 year. Mass-Fix provides a convenient and non-invasive means of predicting for myeloma outcomes. Clinical trial information: NCT01109004. [Table: see text]

Long-term follow-up of BMT CTN 0702 (STaMINA) of postautologous hematopoietic cell transplantation (autoHCT) strategies in the upfront treatment of multiple myeloma (MM)

8506

Background: STaMINA was a phase III trial comparing progression-free survival (PFS) among 758 pts randomized to: 1. second autoHCT then lenalidomide (Len) maintenance (Auto/Auto, n = 247); 2. consolidation with Len/bortezomib/ dexamethasone (RVD) followed by Len maintenance (Auto/RVD, 254); 3. Len maintenance (Auto/Len, 257). All three arms were similar (Stadtmauer JCO 2018). Len maintenance was designed to continue for 3 years and amended to allow continuation until disease progression through a follow up protocol (07LT, NCT#02322320). We report 6 yr follow up for STaMINA and the results of Len discontinuation beyond 3 years. Methods: 07LT was offered to pts who were progression-free at 38 mo; completed planned Len maintenance and were within 4 years of BMT CTN 0702 follow up. Among 431 07LT eligible patients, 273 enrolled and 179 opted to continue maintenance until disease progression. All patients enrolled in STaMINA were reported to the Center for International Blood and Marrow Transplant Research (CIBMTR) and long-term outcomes for patients not enrolled on 07LT (N = 166) were available through this mechanism. Before combining 07LT data and CIBMTR data for LTFU analysis, outcomes in both databases were analyzed separately and confirmed to be comparable. Results: Using intent-to-treat (ITT), 6yr PFS and overall survival (OS) was the same among Auto/Auto (43.9%; 73.1%), Auto/RVD (39.7%, 74.9%) and Auto/Len (40.9%, 76.4%)(p = 0.6; p = 0.8). Protocol defined high risk disease, (HR = 1.53, p < 0.0001) and age (p = 0.03) were adverse risks for PFS. In as treated analysis, 6yr PFS were 49.4%, 39.7% and 38.6% for Auto/auto (170), Auto/RVD (222) and Auto/Len (361), respectively (p = 0.01). 6yr PFS in high risk pts as treated analysis were 43.6% and 26% for Auto/auto and Auto/Len, respectively (p = 0.03). Landmark analysis at 38 mo included 215 pts who continued Len maintenance (either on 07LT study or commercial Len) vs. 207 who stopped. Baseline demographics; study arm on 0702, induction pre-autoHCT were similar. Len discontinuation after 38 mo was associated with inferior PFS (79.5% vs. 61% at 5yr; HR = 1.91, p = 0.0004) but similar OS. Incidence of all second primary malignancies (SPM)(81 cases with 43 heme-malignancies) was associated with age. Conclusions: Long term outcomes are similar using ITT, but as treated analysis suggested a PFS benefit for tandem autoHCT, driven mainly by pts with high risk MM. Len discontinuation even at 38 mo was associated with inferior PFS. Clinical trial information: NCT02322320 .

Ixazomib-dexamethasone (Ixa-Dex) vs physician’s choice (PC) in relapsed/refractory (RR) primary systemic AL amyloidosis (AL) patients (pts) by prior proteasome inhibitor (PI) exposure in the phase III TOURMALINE-AL1 trial

8546

Background: The PI bortezomib is commonly used in first-line therapy of AL, but new therapies are needed that are tolerable in the context of multi-organ dysfunction and that, in RRAL, offer improved outcomes following prior bortezomib. Ixazomib is an oral PI, and in TOURMALINE-AL1, the first phase 3 trial conducted in RRAL, while the first primary endpoint of hematologic overall response rate (ORR) was not met, all clinically relevant time-to-event endpoint data favored Ixa-Dex vs PC (Dispenzieri et al, ASH 2019). Methods: RRAL pts with 1–2 prior therapies were randomized (1:1) to Ixa-Dex (n = 85) or PC (n = 83; Dex plus lenalidomide [n = 47], melphalan [n = 24], cyclophosphamide [n = 10], or thalidomide [n = 2]), stratified by cardiac stage, relapsed vs refractory disease, and prior PI exposure. The primary endpoints were hematologic ORR and 2-yr rate of vital organ deterioration or death. We report subgroup analyses of ORR and outcomes by prior PI exposure. Results: Of the 168 pts enrolled, 90 were PI-naïve and 78 PI-exposed (46 and 39 in the Ixa-Dex arm; 44 and 39 in the PC arm) per stratification; 28 and 27 pts in the Ixa-Dex and PC arms had received bortezomib in their last prior line. Hematologic ORR was 63% vs 50% for Ixa-Dex vs PC (odds ratio [OR] 1.71; 95% confidence interval [CI] 0.74–3.96) in PI-naïve pts, and 41% vs 51% (OR 0.66; 95% CI 0.27–1.62) in PI-exposed pts. For time-to-event outcomes (Table), hazard ratios (HRs) were 0.46–0.85 in favor of Ixa-Dex vs PC in both PI-naïve and PI-exposed pts. Conclusions: Hematologic ORR was higher with Ixa-Dex vs PC in PI-naïve pts but lower in PI-exposed pts (although not statistically significant), and long-term clinically relevant outcomes favored Ixa-Dex in both groups. Based on HRs, the magnitude of benefit appeared similar or greater in PI-naïve vs PI-exposed pts. Clinical trial information: NCT01659658 . [Table: see text]

WT1 heteroclitic epitope immunization following autologous stem cell transplantation in patients with high-risk multiple myeloma (MM)

8016

Background: Host T-cells mount immune responses (IR’s) against Wilms tumor 1 (WT1) in A*0201+MM pts through formation of WT1 peptide fragment (RMFPNAPYL)/HLA-A*0201 complex. We report initial results from MM pts immunized with the WT1 heteroclitic peptide mixture galinpepimut-S (GPS) after autoSCT. Methods: 16 MM pts underwent autoSCT with melphalan conditioning followed by (f/b) lenalidomide maintenance starting 3 months (mos) post-SCT. 13/16 pts presented with high-risk (HR) cytogenetics [t(4;14), t(14;16), del17p, 1q21/25 gain and/or del13q]. GPS was administered with montanide s.c. starting 2 wks post-SCT and q.2 wks thereafter x 6 initial doses f/b boosters q.4 wks x 6 additional doses. GM-CSF was given on days -2 and 0 of each cycle. GPS consisted of 4 peptides: WT1-A1: Y*MFPNAPYL; 427-L (long): RSDELVRHHNMHQRNMTKL; 331-L: PGCNKRYFKLSHLQMHSRKHTG, and 122A1-L: SGQAY*MFPNAPYLPSCLES. 2 of the 4 peptides were mutated at a single residue (*) to induce stronger HLA-binding/reduce tolerance. WT1-specific IR’s were assessed by intracellular IFN-g analyses post-challenge with PBMC’s pulsed with a ‘total pool’ of overlapping 15mers along the entire WT1 protein; or each of the 4 WT1 peptides in GPS; or the non-mutated (native) WT1 peptides corresponding to the 2 heteroclitic sequences. Results: 16 pts; median follow-up: 18 mos (range: 5-31 mos) for survivors; median age: 61.6 y. Overall survival (OS) and progression-free survival (PFS) (95% CI) at 18 mos: 0.88 (0.73-0.99) and 0.62 (0.42-0.97) respectively. Current median PFS: 23.6 mos (15.2 - not reached). No >G2 systemic side effects were observed, however, all pts developed local nodularity at the site of injections which resolved over 2 – 6 wks. Both CD8+ and CD4+ IR’s could be detected at various levels and were induced not only against the heteroclitic peptides (within GPS), but also against the corresponding native WT1 peptide sequences as well as the ‘total pool’ of WT1-derived overlapping peptides. Conclusions: Administration of the novel WT1 heteroclitic peptide immunizer GPS post auto SCT demonstrates favorable safety profile along with encouraging mPFS of currently 23.6 mos in this high-risk MM population. Clinical trial information: NCT01827137.

Response status as predictor of survival after autologous hematopoietic cell transplant (AHCT), without or with consolidation (with bortezomib, lenalidomide (Len) and dexamethasone) and len maintenance (AM vs. ACM) versus tandem AHCT and len maintenance (TAM) for up-front treatment of patients (pts) with multiple myeloma (MM): BMT CTN0702-stamina (NCT01109004)

8010

Background: The Stamina trial primarily aimed to identify the best strategy among AM, ACM, and TAM, leading to longer PFS (LBA-1, ASH, 2016). Here we report on interim, exploratory results of the association between PFS and overall survival (OS) and baseline MM response, risk category, and treatments (Rx). Methods: Pts with MM, < 71 years, < 12 mos from diagnosis were randomized to melphalan 200mg/m2(mel) and AHCT (AM), tandem mel AHCT (TAM), or mel AHCT and 4 cycles of RVD ((ACM). Pts received Len till progression. Pts were stratified by high risk vs. standard ( del13q, del17q, t(4;14), t(14;16), t(14;20) and hypodyploid; high β2 microglobulin). Kaplan Meier estimates of PFS and OS were performed as a function of Rx and ≥ very good partial response (VPGR including CRs) vs. < VGPR. Cox proportional hazard models explored associations between PFS or OS and risk category, Rx, and ≥ VPGR vs. < VGPR. Results: Between 6/2010-11/2013, 758 pts (AM, N = 257; ACM, N = 254; TAM, N = 247) aged 20-70 years (median 57y) were enrolled (24% high-risk). Baseline ≥VGPR responses were 45.5- 49.8%. PFS at 38 months was similar. For < VGPR, 38-mos PFS with TAM:55.8% (95%CI: 45.8%, 64.7%); ACM: 54.0% (44.7%, 62.5%); AM: 50.1% (40.6%, 58.9%); For ≥VGPR, 38-mos PFS with TAM: 57.1% (46.8%, 66.1%); ACM: 60.1% (50.1%, 68.7%); AM: 55.1% (45.1%, 64.0%). Analyzing response, risk category, and Rx revealed no association between baseline response and PFS (Baseline response < VGPR, hazard ratio (HR): 1.21,95% CI: 0.97-1.52) or OS (baseline response < VGPR, HR 1.02, 95%CI:0.70-1.48). High risk category had an adverse association for PFS (HR 1.62, 95% CI: 1.27-2.07) and OS (HR 1.51 (95% CI:1.01-2.26). Conclusions: In this analysis < VGPR at baseline was not associated with PFS or OS. High-risk had an adverse association. Whether accomplishment of CR/minimal residual disease after AM, ACM,or TAM predicts for longer PFS and OS is the subject of ongoing analysis. Clinical trial information: NCT01109004.

Acupuncture for symptom reduction in myeloma patients undergoing hematopoietic stem cell transplantation: A randomized, sham-controlled trial

8021

Background: Hematopoietic stem cell transplantation (HCT) is a potentially curative treatment for a number of hematologic malignancies, but is associated with a high symptom burden for patients. We conducted a randomized sham-controlled trial to evaluate the preliminary efficacy and safety of acupuncture as an integrative treatment for managing common symptoms during HCT. Methods: Adult patients with multiple myeloma undergoing high dose melphalan followed by autologous peripheral blood HCT were randomized to receive either true or sham acupuncture once daily for five days starting on the day after chemotherapy. Symptom burden was assessed with the MD Anderson Symptom Inventory (MDASI) at baseline, during transplantation, and at 15 and 30 days after transplantation. Results: Among 60 participants, symptoms that are significantly reduced by true acupuncture more than sham acupuncture at 15 days include the following: nausea, lack of appetite, and drowsiness (p = 0.042, 0.025, and 0.010, respectively). Patients receiving sham acupuncture were more likely to increase use of pain medication post-transplantation (odds ratio 5.31, p = 0.017). Acupuncture was well tolerated with few attributable adverse events. Conclusions: True acupuncture may prevent escalation of symptoms including nausea, lack of appetite, and drowsiness experienced by patients undergoing autologous HCT, and to reduce the use of pain medications. These findings need to be confirmed in a future definitive study. Clinical trial information: NCT01811862.

The farnesyl transferase inhibitor, tipifarnib, is a potent inhibitor of the MDR1 gene product, P-glycoprotein, and demonstrates significant cytotoxic synergism against human leukemia cell lines

Farnesyl transferase inhibitors (FTIs) target signal-transduction pathways responsible for the proliferation and survival of hematologic malignancies, including acute myelogenous leukemias (AML). Lonafarnib has been shown to be a potent inhibitor of Pgp-mediated drug efflux. On the basis of these findings, we examined the Pgp-inhibitory properties of tipifarnib and assessed its activity when combined with anthracyclines. The effects of tipifarnib on cell proliferation, induction of apoptosis and inhibition of Pgp-mediated anthracycline efflux were analyzed in two human leukemia cell lines overexpressing Pgp (CCRF-CEM and KG1a). Measurement of residual daunorubicin (DNR)-mediated fluorescence after incubation with DNR and tipifarnib demonstrated that tipifarnib significantly inhibited DNR efflux in CCRF-CEM with an IC(50) value less than 0.5 microM. Proliferation and apoptosis assays after exposure to DNR in the presence or absence of tipifarnib demonstrated synergistic inhibition of cellular proliferation, and induction of apoptosis with the combination of tipifarnib and DNR. Similar data was obtained with an enantiomer of tipifarnib that possesses no FTI activity. Incubation with tipifarnib and DNR did not interfere with inhibition of the post-translational processing of HDJ-2. These data suggest that tipifarnib possesses Pgp-inhibitory activity in addition to its FTI activity. In high risk and refractory patients these properties may be exploited as a dual targeting mechanism in the therapy of AML.

Classic Kaposi's sarcoma associated with human herpesvirus 8 infection in a 13-year-old male: a case report

PURPOSE

Classic Kaposi's sarcoma (KS) is rare in children. Although its etiology is not fully understood, human herpesvirus 8 (HHV-8) is present in the angiogenic lesions. We report an HIV-negative, 13-year-old patient of Sicilian descent with HHV-8-associated classic KS to facilitate the diagnosis and treatment of this entity in children.

EXPERIMENTAL DESIGN

DNA was extracted from the skin specimen of the patient and analyzed via PCR assay and Southern blot hybridization for HHV-8 DNA. The amplified HHV-8 DNA was cloned, sequenced, and compared with the prototype HHV-8-KS330/BAM.

RESULTS

The patient presented with purpuric lesions on the distal lower extremities and the tip of his nose, associated with thrombocytopenia and leukopenia, suggesting an immune-mediated cytopenia. While on prednisone, he developed marked vascular proliferation in the groins. Biopsy of the skin lesions showed KS, and HHV-8 was detected in the tissues by PCR. Sequence analysis of the amplified DNA was homologous to the prototype HHV-8-KS330/BAM. His HHV-8 strain was the A subgroup, the type associated with Mediterranean classic KS. Stopping prednisone and treatment with IFN-alpha and IgG resulted in regression of the groin lesions.

CONCLUSIONS

This report emphasizes the importance of recognizing classic KS in children and avoiding immunosuppressive therapies in indolent classic KS. The diagnostic and therapeutic strategies were effective and well tolerated.