Purpose of review

Hematologic malignancies are common and difficult to treat in older adults. In this review, we focus on recent updates in diseases with several novel agents relevant to older adults-acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), and multiple myeloma (MM).

Recent findings

In AML, CPX-351 offers a new induction chemotherapy for secondary AML that prolongs survival, and venetoclax and IDH inhibitors are efficacious and well tolerated. In CLL, chemoimmunotherapy is being replaced by monoclonal antibodies and small molecule inhibitors that are more effective and better tolerated. In MM, new immunomodulatory drugs, proteasome inhibitors, and monoclonal antibodies have expanded treatment options for older patients. The introduction of novel agents has dramatically shifted the landscape of therapeutic options for older adults with hematologic malignancies. Clinical trials in older adults are needed to expand treatment options for these patients.

Chimeric antigen receptor T-cell (CAR-T) therapy targeted against B-cell maturation antigen (BCMA) in multiple myeloma (MM) has produced rapid responses but many eventually relapse. In light of this new treatment, novel predictors of progression-free survival (PFS) are needed. We performed a single institution analysis of 54 BCMA-CAR-T patients. We analyzed patient's overall response rate (ORR) by the IMWG criteria, involved serum-free light chains (iFLC), and minimal residual disease testing by next-generation sequencing (MRD-NGS). Between patients who achieved a ≤SD and those who achieved a ≥PR, PFS differed significantly (p < 0.0001); though there was no difference between patients who achieved a ≥CR vs. VGPR/PR (p = 0.2). In contrast, patients who achieved a nonelevated iFLC at 15 days (p < 0.0001, HR = 6.8; 95% CI, 2.7-17.3) or 30 days (p < 0.001, HR = 16.7; 95% CI, 3.9-71.7) had a prolonged PFS compared with those with an elevated iFLC. Patients achieving MRD-NGS less than the detectable limit at a sensitivity of 10^-6 had a better PFS than those with detectable disease at 1 month (p = 0.02) and 3 months (p = 0.02). In conclusion, achieving a nonelevated iFLC and an undetectable MRD-NGS quickly were factors that were strongly associated with improved PFS. Further studies are needed to confirm the role of these markers in MM patients receiving CAR-T therapies.

B-cell maturation antigen-targeted chimeric antigen receptor T-cell therapy (BCMA CAR-T) is an effective treatment of relapsed refractory multiple myeloma (MM). However, the pattern of infectious complications is not well elucidated. We performed a single-center retrospective analysis of infection outcomes up to 1 year after BCMA CAR-T for MM from 2018 to 2020. Fifty-five patients with MM were treated with BCMA CAR-T. Before lymphodepletion (LD), 35% of patients had severe hypogammaglobulinemia and 18% had severe lymphopenia. Most patients (68%) received bridging chemotherapy (BC) before LD. In the first month after CAR-T, 98% patients had grade 3 to 4 neutropenia. At 1 year after infusion, 76% patients had hypogammaglobulinemia. With a median follow-up of 6.0 months (95% confidence interval, 4.7-7.4), there were a total of 47 infection events in 29 (53%) patients: 40% bacterial, 53% viral, and 6% fungal. Most (92%) were mild-moderate and of the lower/upper respiratory tract system (68%). Half of the infections (53%) occurred in the first 100 days after CAR-T infusion. Although no statistically significant risk factors for infection were identified, prior lines of therapy, use of BC, recent infections, and post-CAR-T lymphopenia were identified as possible risk factors that need to be further explored. This is the largest study to date to assess infectious complications after BCMA CAR-T. Despite multiple risk factors for severe immunosuppression in this cohort, relatively few life-threatening or severe infections occurred. Further larger studies are needed to better characterize the risk factors for and occurrence of infections after BCMA CAR-T.

We investigated antibody and coronavirus disease 2019 (COVID-19)-specific T-cell mediated responses via ultra-deep immunosequencing of the T-cell receptor (TCR) repertoire in patients with plasma cell dyscrasias (PCD). We identified 364 patients with PCD who underwent spike antibody testing using commercially available spike-receptor binding domain immunoglobulin G antibodies ≥2 weeks after completion of the initial two doses of mRNA vaccines or one dose of JNJ-78436735. A total of 56 patients underwent TCR immunosequencing after vaccination. Overall, 86% tested within 6 months of vaccination had detectable spike antibodies. Increasing age, use of anti-CD38 or anti-B-cell maturation antigen therapy, and receipt of BNT162b2 (vs. mRNA-1273) were associated with lower antibody titres. We observed an increased proportion of TCRs associated with surface glycoprotein regions of the COVID-19 genome after vaccination, consistent with spike-specific T-cell responses. The median spike-specific T-cell breadth was 3.11 × 10^-5 , comparable to those in healthy populations after vaccination. Although spike-specific T-cell breadth correlated with antibody titres, patients without antibody responses also demonstrated spike-specific T-cell responses. Patients receiving mRNA-1273 had higher median spike-specific T-cell breadth than those receiving BNT162b2 (p = 0.01). Although patients with PCD are often immunocompromised due to underlying disease and treatments, COVID-19 vaccination can still elicit humoral and T-cell responses and remain an important intervention in this patient population.

Few clinical studies have reported results of measurable residual disease (MRD) assessments performed as part of routine practice. Herein we present our single-institution experience assessing MRD in 234 multiple myeloma (MM) patients (newly diagnosed [NDMM = 159] and relapsed [RRMM = 75]). We describe the impact of depth, duration, and direction of response on prognosis. MRD assessments were performed by next-generation sequencing of immunoglobulin genes with a sensitivity of 10-6. Those achieving MRD negativity at 10-6, as well as 10-5, had superior median progression-free survival (PFS). In the NDMM cohort, 40% of the patients achieved MRD negativity at 10-6 and 59% at 10-5. Median PFS in the NDMM cohort was superior in those achieving MRD at 10-5 vs <10-5 (PFS: 87 months vs 32 months; P < .001). In the RRMM cohort, 36% achieved MRD negativity at 10-6 and 47% at 10-5. Median PFS was superior for the RRMM achieving MRD at 10-5 vs <10-5 (PFS: 42 months vs 17 months; P < .01). Serial MRD monitoring identified 3 categories of NDMM patients: (A) patients with ≥3 MRD 10-6 negative samples, (B) patients with detectable but continuously declining clonal numbers, and (C) patients with stable or increasing clonal number (≥1 log). PFS was superior in groups A and B vs C (median PFS not reached [NR], NR, 55 respectively; P < .001). This retrospective evaluation of MRD used as part of clinical care validates MRD as an important prognostic marker in NDMM and RRMM and supports its use as an endpoint in future clinical trials as well as for clinical decision making.

International Myeloma Working Group (IMWG) response criteria require refrigerated 24-hour urine specimens for most patients. However, given that serum free light chain testing has been shown to outperform 24-hour urine immunofixation as a prognostic marker, the importance of maintaining urine testing options or requirements within each level of IMWG response criteria has not been investigated. We analyzed responses to induction therapy for all transplant-eligible patients with multiple myeloma at our institution over a 3-year period using traditional versus 'urine-free' IMWG response criteria (where references to urine were removed from the descriptions for every depth of response). Of 281 evaluable patients, responses changed for only 4% of patients (95% confidence interval 2-7%) using urine-free criteria. Our results call into question the continued requirement for 24-hour urine measurements as part of IMWG response assessments for all patients. Research into the prognostic performance of urine-free IMWG criteria is ongoing.

Multiple myeloma patients undergoing autologous stem cell transplantation (ASCT) may receive benzodiazepine or zolpidem-class (B/Z) medications despite their risks in older patients. Of 205 myeloma patients (36% aged 65+) who underwent ASCT at our institution between 2017 and 2018, we found that B/Z prescription rates for anxiety/insomnia rose significantly from 26% before ASCT to 38% at discharge and 39% at Day +100. B/Z initiation while hospitalized was a strong predictor of B/Z persistence at Day +100. Our findings highlight the role of these potentially inappropriate medications during hospitalizations for ASCT, a period where nonpharmacologic strategies for managing anxiety/insomnia may be feasible.

Background

For patients with multiple myeloma receiving high-dose chemotherapy followed by autologous stem cell transplantation (SCT), acute life disruptions and symptom burden may lead to worsened quality of life (QOL) and increased emotional distress. Digital life coaching (DLC), whereby trained coaches deliver personalized well-being-related support via phone calls and SMS text messaging, has been shown to improve QOL among SCT survivors. However, DLC has not been investigated during the acute peri-SCT period, which is generally characterized by symptomatic exacerbations and 2-week hospitalizations.

Objective

We launched a single-arm pilot study to investigate the feasibility of patient engagement with DLC during this intensive period.

Methods

We approached English-speaking adult patients with multiple myeloma undergoing autologous SCT at our center. Enrolled patients received 16 weeks of virtual access to a life coach beginning on day -5 before SCT. Coaches used structured frameworks to help patients identify and overcome personal barriers to well-being. Patients chose the coaching topics and preferred communication styles. Our primary endpoint was ongoing DLC engagement, defined as bidirectional conversations occurring at least once every 4 weeks during the study period. Secondary endpoints were electronic patient-reported outcome assessments of QOL, distress, and sleep disturbances.

Results

Of the 20 patients who were screened, 17 (85%) chose to enroll and 15 (75%) underwent SCT as planned. Of these 15 patients (median age 65 years, range 50-81 years), 11 (73%) demonstrated ongoing DLC engagement. The median frequency of bidirectional conversations during the 3-month study period was once every 6.2 days (range 3.9-28 days). During index hospitalizations with median lengths of stay of 16 days (range 14-31 days), the median frequency of conversations was once every 5.3 days (range 2.7-15 days). Electronic patient-reported outcome assessments (94% adherence) demonstrated an expected QOL nadir during the second week after SCT. The prevalence of elevated distress was highest immediately before and after SCT, with 69% of patients exhibiting elevated distress on day -5 and on day +2.

Conclusions

DLC may be feasible for older patients during intensive hospital-based cancer treatments such as autologous SCT for multiple myeloma. The limitations of our study include small sample size, selection bias among enrolled patients, and heterogeneity in DLC use. Based on the positive results of this pilot study, a larger phase 2 randomized study of DLC during SCT is underway to investigate the efficacy of DLC with regard to patient well-being.

Trial registration

ClinicalTrials.gov NCT04432818; https://clinicaltrials.gov/ct2/show/NCT04432818.

Background

The monoclonal antibody daratumumab, approved for treating myeloma, targets CD38, a protein on myeloma and also on CD34+ hematopoietic progenitor cells. Because mobilized CD34+ cells are critical for stem cell transplant, we investigated the in vitro activity of daratumumab on mobilized CD34+ cells from myeloma patients with no prior exposure to daratumumab.

Methods

We determined the number of CD38 molecules per CD34+ cell, and whether daratumumab bound to CD34+ cells, whether C1q bound to daratumumab-coated CD34+ cells and whether daratumumab-related complement-dependent cytotoxicity (CDC) occurred. We also examined CD34+ cell progenitor cell colony capacity in assays with pre-plating incubation of CD34+ cells with daratumumab alone or with daratumumab and the CD59 inhibitory antibody BRIC229, and also assessed CD34+ cell responses to increasing doses of daratumumab in caspase 3/7 activity assays.

Results

Although 75% of mobilized CD34+ cells co-express CD38, CD38 was minimally present on CD34+ cells compared to Daudi and KG-1 controls, C1q did not bind to daratumumab-coated CD34+ cells, and CDC did not occur. CD34+ cells incubated in complement-rich human serum with daratumumab alone or with daratumumab and BRIC229, and then plated in progenitor cell assays, produced similar numbers of colonies as controls. In progenitor cell assays with cryopreserved or fresh unselected or CD34-selected cells, daratumumab did not affect progenitor cell capacity, and in caspase 3/7 activity assays CD34+ cells were not affected by increasing doses of daratumumab.

Conclusion

In vitro, daratumumab is not toxic to mobilized CD34+ progenitor cells from myeloma patients.