Outcomes of autologous hematopoietic cell transplantation in myeloma patients aged ≥75 years

Cellular therapies in older adults with hematological malignancies: A case-based, state-of-the-art review

Cellular therapies, including autologous stem cell transplant (ASCT), allogeneic hematopoietic cell transplantation (alloHCT), and chimeric antigen receptor- (CAR-) T cell therapies are essential treatment modalities for many hematological malignancies. Although their use in older adults has substantially increased within the past decades, cellular therapies represent intensive treatment approaches that exclude a large percentage of older adults due to comorbidities and frailty. Under- and overtreatment in older adults with hematologic malignancy is a challenge and many treatment decisions are influenced by chronologic age. The advent of efficient and well-tolerated newer treatment approaches for multiple myeloma has challenged the role of ASCT. In the modern era, there are no randomized clinical trials of transplant versus non-transplant strategies for patients ≥65 years. Nonetheless, ASCT is feasible for selected older patients and does not result in long-term compromise in quality of life. AlloHCT is the only curative approach for acute myeloid leukemia of intermediate and unfavourable risk but carries a significant risk for non-relapse mortality depending on comorbidities, general fitness, and transplant-specific characteristics, such as intensity of conditioning and donor choice. However, alloHCT is feasible in appropriately-selected older adults. Early referral for evaluation is strongly encouraged as this is the most obvious barrier. CAR-T cell therapies have shown unprecedented clinical efficacy and durability in relapsed and refractory diffuse large B cell lymphoma. Its use is well tolerated in older adults, although evidence comes from limited case numbers. Whether patients who are deemed unfit for ASCT qualify for CAR-T cell therapy remains elusive, but the tolerability and efficacy of CAR-T cell therapy appears promising, especially for older patients. The evidence from randomized trials is strong in favor of using a comprehensive geriatric assessment (CGA) to reduce treatment-related toxicities and guide treatment intensity in the care for solid tumors; its use for evaluation of cellular therapies is less evidence-based. However, CGA can provide useful information on patients' fitness, resilient mechanisms, and reveal potential optimization strategies for compensating for vulnerabilities. In this narrative review, we will discuss key questions on cellular therapies in older adults based on illustrative patient cases.

Benefits of Autologous Stem Cell Transplantation for Elderly Myeloma Patients in the Last Quarter of Life

Although survival outcomes have improved dramatically over the last few decades in newly diagnosed myeloma patients, elderly patients have not yielded the same magnitude of benefit as evidenced by higher rates of reported myeloma-related deaths in patients over the age of 75. This is of particular importance given this cohort comprises a large proportion of myeloma patients with the median age of diagnosis being 70 years. One contributor to this discrepancy is reduced use of high-dose therapy and autologous stem cell transplantation (HDT/ASCT) in this population because of concerns for increased toxicity and safety. The objective of this retrospective analysis is to evaluate survival and safety outcomes in 53 newly diagnosed patients ≥74 years of age who underwent HDT/ASCT at our institution in comparison to 122 control patients in the same age bracket who did not undergo stem cell transplantation during this same time period. Patients treated at our institution were identified in our institutional myeloma database by age. They were all treated between November 2006 and October 2016 at the Winship Cancer Institute of Emory University. Fifty-three patients were identified who had undergone HDT/ASCT, and, to assess the relative benefit of ASCT, 122 control patients in the same age range were also identified who did not undergo HDT/ASCT during the same time period. The median age for the entire cohort was 77 years (74 years in the ASCT group versus 78 in the non-ASCT group). Median time to ASCT was 6 months (range 2-57 months). There were no gender or race differences between the 2 groups, although a higher proportion of high-risk patients underwent HDT/ASCT. Ninety-three percent of ASCT patients received triplet induction therapy with a proteasome inhibitor and immunomodulatory agent backbone in comparison to only 55% of patients the non-ASCT group. The median progression-free survival (PFS) for the ASCT group was 50 months versus 30 months in the non-ASCT group. The median overall survival (OS) was 80 months versus 40 months, respectively. In high-risk patients, the median PFS was 60.8 months, and the median OS was 77.8 months in the ASCT group compared to 26 months and 38 months in the non-ASCT group, respectively. There were no transplant-related deaths within the first 100 days in the ASCT group. This study offers real-world perspective and data on the safety and survival benefit of ASCT in the elderly population with a near doubling of OS when compared to those treated with similar regimens and modern agents without ASCT. These data provide a rationale for offering ASCT in elderly patients pending a thorough pretransplantation evaluation.

"I took the road less traveled, and that has made all the difference": Making a case for high-dose therapy and autologous stem cell transplantation in elderly patients with newly diagnosed multiple myeloma

LAY SUMMARY

Elderly patients with myeloma derive benefits from transplantation similar to those for younger patients. Age should not be the sole criterion for determining transplant eligibility. Performance status assessment and other tools for assessing comorbidities such as the Charlson comorbidity score may potentially help in determining transplant eligibility and will allow us to move away from our heavy reliance on numerical age.

Outcomes of upfront autologous hematopoietic cell transplantation in patients with multiple myeloma who are 75 years old or older

BACKGROUND

Consolidative autologous hematopoietic stem cell transplantation (AHCT) is commonly used for patients with multiple myeloma (MM). We studied AHCT use and outcomes in patients with MM ≥75 years old.

METHODS

Patients with MM ≥75 years old receiving AHCT between 2013 and 2017 in the United States were identified using the Center for International Blood and Marrow Transplant Research database. Relapse and/or progression (REL), progression-free survival (PFS), and overall survival (OS) were modeled using Cox proportional hazards models. Covariates used were age, sex, Karnofsky performance score (KPS), HCT-comorbidity index (HCT-CI), International Staging System and/or Durie-Salmon stage, high-risk cytogenetics, melphalan dose, and disease status at and 1 year after transplant. AHCT utilization rate using the Surveillance, Epidemiology, and End Results database was used to estimate specific incidence among ≥75 years old by race and gender.

RESULTS

Of 360 patients, 63% were male, 84% were White, 56% had KPS <90, and 57% had HCT-CI ≥3. The 100-day transplant-related mortality was 1% (0%-2%) with a 2-year REL rate of 27% (95% confidence interval [CI], 22%-33%), PFS of 66% (95% CI, 60%-72%), and OS of 83% (95% CI, 78%-87%). On multivariate analysis, only high-risk cytogenetics was associated with REL risk and decreased PFS. In White males, transplant utilization rate was 5.2%-5.8% compared to 3.5%-4.0% in African American males (P = .02). There was 3.37-3.79% transplant utilization in White females compared to 1.88-2.12% in African American females (P < .01).

CONCLUSIONS

The use of AHCT was associated with excellent 2-year outcomes in this selected MM population ≥75 years old. Transplant utilization for patients ≥75 years old remains low with significant racial and gender disparities.

Autologous stem cell transplantation for multiple myeloma patients aged ≥ 75 treated with novel agents

Autologous stem cell transplantation (ASCT) has been used for treating multiple myeloma (MM) for over three decades and is generally reserved for patients younger than 65. Herein we report on outcomes of outpatient ASCT in a cohort of patients with MM aged ≥75 years. Between October 2005 and August 2020, 50 patients aged ≥75 years, received an ASCT at Mayo Clinic, Rochester. Median time from diagnosis to ASCT was 6.85 months (IQR 5.2-10.52) and 50%. received reduced intensity conditioning with melphalan 140 mg/m². 48% of patients completed the ASCT without requiring hospitalization and 52% (n = 26) of patients required hospitalization with a median duration of hospital admission of 9 days (IQR 5-13). Reasons for hospitalization included fever or infection (32%), cardiac arrhythmia (36%), and dehydration (32%). Overall response rate was 100% with a complete response seen in 57% of patients. Median overall survival and progression free survival for the cohort were 82 months and 33 months, respectively. One patient died within 100 days of transplant representing a 2% 100-day mortality rate. ASCT is safe and efficacious in carefully selected MM patients aged 75 or above and we believe that age should not be an exclusion factor for ASCT in MM.

Multiple myeloma-A painful disease of the bone marrow

Multiple myeloma is a bone marrow neoplasia with an incidence of 6/100,000/year in Europe. While the disease remains incurable, the development of novel treatments such as autologous stem cell transplantation, proteasome inhibitors and monoclonal antibodies has led to an increasing subset of patients living with long-term myeloma. However, more than two thirds of patients suffer from bone pain, often described as severe, and knowledge on the pain mechanisms and its effect on their health-related quality of life (HRQoL) is limited. In this review, we discuss the mechanisms of myeloma bone disease, the currently available anti-myeloma treatments and the lessons learnt from clinical studies regarding HRQoL in myeloma patients. Moreover, we discuss the mechanisms of cancer-induced bone pain and the knowledge that animal models of myeloma-induced bone pain can provide to identify novel analgesic targets. To date, information regarding bone pain and HRQoL in myeloma patients is still scarce and an effort should be made to use standardised questionnaires to assess patient-reported outcomes that allow inter-study comparisons of the available clinical data.

Autologous stem cell transplantation is safe in selected elderly multiple myeloma patients

OBJECTIVES

ASCT is currently the "gold standard" first-line treatment for multiple myeloma patients younger than 65 years old, and limited data on efficacy and safety in older patients are available.

METHODS

We retrospectively analyzed a cohort of 83 newly diagnosed multiple myeloma patients aged 65 or older. All patients were evaluated for fitness at diagnosis and after bortezomib-based induction treatment.

RESULTS AND CONCLUSIONS

All patients collected an adequate PBSC graft, mainly after G-CSF plus cyclophosphamide; a median of 6.47 × 10⁶ /kg CD34 + cells was collected. The conditioning regimen consisted of melphalan 100, 140 and 200 mg/m² in 40, 15 and 28 patients, respectively. Median time to neutrophils' and platelets' recovery was 11 and 12 days, respectively. Adverse events of any grade were referred by 40% of patients. The overall response rate was 93%, CR/sCR were 39%. Median PFS was 35 months; median OS was not reached. In our study cohort, the achievement of at least VGPR after induction therapy and the obtainment of CR/sCR after ASCT are the only parameters that were associated with an improved PFS. ASCT is an effective and safe first-line treatment approach, a careful patients selection reduce the toxicity of the procedure.