HA-1-targeted T cell receptor (TCR) T cell therapy for recurrent leukemia after hematopoietic stem cell transplantation.

Relapse is the leading cause of death after allogeneic hematopoietic stem cell transplantation (HCT) for leukemia. T cells engineered by gene transfer to express T cell receptors (TCR; TCR-T) specific for hematopoietic-restricted minor histocompatibility (H) antigens may provide a potent selective anti-leukemic effect post-HCT. We conducted a phase I clinical trial employing a novel TCR-T product targeting the minor H antigen HA-1 to treat or consolidate treatment of persistent or recurrent leukemia and myeloid neoplasms. The primary objective was to evaluate the feasibility and safety of administration of HA-1 TCR-T post-HCT. CD8+ and CD4+ T cells expressing the HA-1 TCR and a CD8-co-receptor were successfully manufactured from HA-1 disparate HCT donors. One or more infusions of HA-1 TCR-T following lymphodepleting chemotherapy were administered to nine HCT recipients who had developed disease recurrence post-HCT. TCR-T cells expanded and persisted in vivo after adoptive transfer. No dose-limiting toxicities occurred. Although the study was not designed to assess efficacy, four patients achieved or maintained complete remissions following lymphodepletion and HA-1 TCR-T, with one ongoing at >2 years. Single-cell RNA sequencing of relapsing/progressive leukemia after TCR-T therapy identified upregulated molecules associated with T cell dysfunction or cancer cell survival. HA-1 TCR-T therapy appears feasible and safe and shows preliminary signals of efficacy. This clinical trial is registered at clinicaltrials.gov as NCT03326921.

Factors associated with outcomes after a second CD19-targeted CAR T-cell infusion for refractory B-cell malignancies.

CD19-targeted chimeric antigen receptor-engineered (CD19 CAR) T-cell therapy has shown significant efficacy for relapsed or refractory (R/R) B-cell malignancies. Yet, CD19 CAR T cells fail to induce durable responses in most patients. Second infusions of CD19 CAR T cells (CART2) have been considered as a possible approach to improve outcomes. We analyzed data from 44 patients with R/R B-cell malignancies (acute lymphoblastic leukemia [ALL], n = 14; chronic lymphocytic leukemia [CLL], n = 9; non-Hodgkin lymphoma [NHL], n = 21) who received CART2 on a phase 1/2 trial (NCT01865617) at our institution. Despite a CART2 dose increase in 82% of patients, we observed a low incidence of severe toxicity after CART2 (grade ≥3 cytokine release syndrome, 9%; grade ≥3 neurotoxicity, 11%). After CART2, complete response (CR) was achieved in 22% of CLL, 19% of NHL, and 21% of ALL patients. The median durations of response after CART2 in CLL, NHL, and ALL patients were 33, 6, and 4 months, respectively. Addition of fludarabine to cyclophosphamide-based lymphodepletion before the first CAR T-cell infusion (CART1) and an increase in the CART2 dose compared with CART1 were independently associated with higher overall response rates and longer progression-free survival after CART2. We observed durable CAR T-cell persistence after CART2 in patients who received cyclophosphamide and fludarabine (Cy-Flu) lymphodepletion before CART1 and a higher CART2 compared with CART1 cell dose. The identification of 2 modifiable pretreatment factors independently associated with better outcomes after CART2 suggests strategies to improve in vivo CAR T-cell kinetics and responses after repeat CAR T-cell infusions, and has implications for the design of trials of novel CAR T-cell products after failure of prior CAR T-cell immunotherapies.

Late Events after Treatment with CD19-Targeted Chimeric Antigen Receptor Modified T Cells.

CD19-targeted chimeric antigen receptor-modified T cell (CAR-T cell) therapy has shown excellent antitumor activity in patients with relapsed/refractory B cell malignancies, with very encouraging response rates and outcomes. However, the late effects following this therapy remain unknown. Here we report late adverse events-defined as starting or persisting beyond 90 days after CAR-T cell infusion-in patients who survived at least 1 year after therapy. The median duration of follow-up was 28.1 months (range, 12.5 to 62.6 months). At last follow-up, 73% of patients were still alive and 24% were in ongoing complete remission (CR). The most common late adverse event was hypogammaglobulinemia (IgG <400 mg/dL or i.v immunoglobulinm (IVIG) replacement, observed in 67% of the patients with available data. Infection density was .55 infection/100 days at risk (2.08 per patient-year). The majority (80%) of the infections were treated in the outpatient setting, and 5% necessitated admission to the intensive care unit (ICU). Subsequent malignancies occurred in 15% of patients, including 5% with myelodysplastic syndrome (MDS). Among patients with ongoing CR and with no MDS, 16% experienced prolonged cytopenia requiring transfusions or growth factor support. Graft-versus-host disease occurred in 3 of 15 patients (20%) who had undergone previous allogeneic hematopoietic cell transplantation. Most of the late events observed in this cohort were not severe, and many could be related to previous or subsequent therapies, suggesting a safe long-term profile of CD19-targeted CAR-T cell immunotherapy.

Survivorship after Autologous Hematopoietic Cell Transplantation for Lymphoma and Multiple Myeloma: Late Effects and Quality of Life.

Although autologous hematopoietic cell transplantation (AHCT) is standard therapy for patients with lymphoma and multiple myeloma (MM), few studies have addressed late effects and quality of life (QoL) in long-term survivors after AHCT. Using long-term follow-up (LTFU) annual questionnaires with self-reported outcomes, we surveyed 665 patients who were at ≥5 years after AHCT for the diagnosis of lymphoma or MM. Three-hundred and eighty-nine patients completed the questionnaire (58% response rate) at a median of 11 years (range, 5-30 years) after AHCT. The median patient age was 63 years (range, 22-88 years) in the 268 patients with lymphoma and 69 years (range, 34-84 years) in the 121 patients with multiple myeloma. The most commonly reported medical conditions (>10% incidence) were sexual dysfunction, history of shingles, cataracts, osteoporosis or osteopenia, joint replacement, and skin cancer. Current medication use was more frequent in the patients with MM for infection prevention/treatment (19% for MM versus 5% lymphoma; P < .001), hypertension (41% versus 26%; P = .004), osteoporosis (23% versus 10%; P < .001), and pain (32% versus 11%, P < .001). Treated hypothyroidism was more common in lymphoma patients. In multivariate analysis combining lymphoma and MM, worse physical functioning was associated with older age, shorter interval since AHCT, comorbidities, relapse, and treatment for depression and/or pain. Worse mental functioning was associated with younger age and treatment for anxiety, depression, or pain. In conclusion, AHCT survivors report generally good QoL but many late effects and symptoms that are potentially amenable to intervention.

Patient-Reported Neuropsychiatric Outcomes of Long-Term Survivors after Chimeric Antigen Receptor T Cell Therapy.

CD19-targeted chimeric antigen receptor (CAR) modified T cell immunotherapy is a novel treatment with promising results in patients with relapsed/refractory lymphoid malignancies. CAR T cell therapy has known early toxicities of cytokine release syndrome and neurotoxicity, but little is known about long-term neuropsychiatric adverse effects. We have used patient-reported outcomes, including Patient-Reported Outcomes Measurement Information System (PROMIS) measures, to assess neuropsychiatric and other patient-reported outcomes of 40 patients with relapse/refractory chronic lymphocytic leukemia, non-Hodgkin lymphoma, and acute lymphoblastic leukemia 1 to 5 years after treatment with CD19-targeted CAR T cells. Mean T scores of PROMIS domains of global mental health, global physical health, social function, anxiety, depression, fatigue, pain, and sleep disturbance were not clinically meaningfully different from the mean in the general US population. However, 19 patients (47.5%) reported at least 1 cognitive difficulty and/or clinically meaningful depression and/or anxiety, and 7 patients (17.5%) scored ≤40 in global mental health, indicating at least 1 standard deviation worse than the general population mean. Younger age was associated with worse long-term global mental health (P = .02), anxiety (P = .001), and depression (P= .01). Anxiety before CAR T cell therapy was associated with increased likelihood of anxiety after CAR T cell therapy (P = .001). Fifteen patients (37.5%) reported cognitive difficulties after CAR T cell therapy. Depression before CAR T cell therapy was statistically significantly associated with higher likelihood of self-reported post-CAR T cognitive difficulties (P = .02), and there was a trend for an association between acute neurotoxicity and self-reported post-CAR T cognitive difficulties (P = .08). Having more post-CAR T cognitive difficulties was associated with worse global mental health and global physical health. Our study demonstrates overall good neuropsychiatric outcomes in 40 long-term survivors after CAR T cell therapy. However, nearly 50% of patients in the cohort reported at least 1 clinically meaningful negative neuropsychiatric outcome (anxiety, depression, or cognitive difficulty), indicating that a significant number of patients would likely benefit from mental health services following CAR T cell therapy. Younger age, pre-CAR T anxiety or depression, and acute neurotoxicity may be risk factors for long-term neuropsychiatric problems in this patient population. Larger studies are needed to confirm these findings.

Bone Health Management After Hematopoietic Cell Transplantation: An Expert Panel Opinion from the American Society for Transplantation and Cellular Therapy.

Bone health disturbances commonly occur after hematopoietic cell transplantation (HCT) with loss of bone mineral density (BMD) and avascular necrosis (AVN) foremost among them. BMD loss is related to pretransplantation chemotherapy and radiation exposure and immunosuppressive therapy for graft-versus-host-disease (GVHD) and results from deficiencies in growth or gonadal hormones, disturbances in calcium and vitamin D homeostasis, as well as osteoblast and osteoclast dysfunction. Although the pathophysiology of AVN remains unclear, high-dose glucocorticoid exposure is the most frequent association. Various societal treatment guidelines for osteoporosis exist, but the focus is mainly on menopausal-associated osteoporosis. HCT survivors comprise a distinct population with unique comorbidities, making general approaches to bone health management inappropriate in some cases. To address a core set of 16 frequently asked questions (FAQs) relevant to bone health in HCT, the American Society of Transplant and Cellular Therapy Committee on Practice Guidelines convened a panel of experts in HCT, adult and pediatric endocrinology, orthopedics, and oral medicine. Owing to a lack of relevant prospective controlled clinical trials that specifically address bone health in HCT, the answers to the FAQs rely on evidence derived from retrospective HCT studies, results extrapolated from prospective studies in non-HCT settings, relevant societal guidelines, and expert panel opinion. Given the heterogenous comorbidities and needs of individual HCT recipients, answers to FAQs in this article should be considered general recommendations, with good medical practice and judgment ultimately dictating care of individual patients. Readers are referred to the Supplementary Material for answers to additional FAQs that did not make the core set.

Rates and Risk Factors for Post-Traumatic Stress Disorder Symptomatology among Adult Hematopoietic Cell Transplant Recipients and Their Informal Caregivers.

Hematopoietic cell transplant (HCT) can cause significant distress in patients and their informal caregivers. Despite advances in reduced-intensity conditioning and supportive care, few recent studies have reported rates of clinically significant post-traumatic stress disorder (PTSD) symptomatology. Goals of the current study were to examine rates of PTSD and distress in patients and caregivers and to identify sociodemographic and clinical risk factors for PTSD. As part of an annual survivorship survey, 2157 HCT recipients and their caregivers were mailed self-report measures of PTSD and distress. Patients also completed self-report measures of sociodemographic information (eg, age, sex, employment status). Clinical variables (eg, time since transplant, transplant type) were captured in the transplant database. A total of 691 recipients (56% age 60 or above at the time of survey, 47% women, median 10.1 years post-HCT) and 333 caregivers provided PTSD data and were included in the current analyses. More caregivers reported PTSD (6.6%) than patients (3.3%; P = .02). Patients or caregivers who had PTSD reported significantly higher distress related to uncertainty, family strain, medical demands, finances, identity, and health burden (P < .0001) compared with those without PTSD. Patient but not caregiver PTSD was associated with more recent transplant (P = .01 and P = .16, respectively). Rates of PTSD are relatively low in long-term survivors of HCT and their caregivers. Nevertheless, results are consistent with other studies of cancer caregiving suggesting that caregivers often experience greater distress than patients. Timely referral to psychosocial services should be offered to both HCT recipients and caregivers reporting symptoms of PTSD.

Use of Chimeric Antigen Receptor T Cell Therapy in Clinical Practice for Relapsed/Refractory Aggressive B Cell Non-Hodgkin Lymphoma: An Expert Panel Opinion from the American Society for Transplantation and Cellular Therapy.

Axicabtagene ciloleucel (YESCARTA; Kite Pharma, a Gilead Company, Los Angeles CA) and tisagenlecleucel (KYMRIAH; Novartis Pharmaceuticals Corp., Basel, Switzerland) are two CD19-directed chimeric antigen receptor (CAR) T cell products currently approved by the US Food and Drug Administration; the European Medicines Agency; Health Canada; Ministry of Health, Labor and Welfare (Japan); and Therapeutic Goods Administration (Australia) for treatment of specific subtypes of relapsed/refractory aggressive B cell non-Hodgkin lymphoma (NHL). Although this approval has been transformative in the use of cellular immunotherapy in lymphoma, there are concerns regarding appropriate use of this novel therapy and of short- and long-term toxicities. To address these issues, representatives of the American Society of Transplantation and Cellular Therapy convened to recognize and address key issues surrounding the clinical application of CD19 CAR T cell therapy in B cell lymphomas, in collaboration with worldwide experts. The aim of this article is to provide consensus opinion from experts in the fields of hematopoietic cell transplantation, cellular immunotherapy, and lymphoma regarding key clinical questions pertinent to the use of CD19 CAR T cell products for the treatment of NHL. As the clinical practice using CAR T cells grows worldwide, we anticipate that this guidance will be relevant for hematology/oncology physicians who care for patients with lymphomas.

Clinical Utilization of Chimeric Antigen Receptor T Cells in B Cell Acute Lymphoblastic Leukemia: An Expert Opinion from the European Society for Blood and Marrow Transplantation and the American Society for Blood and Marrow Transplantation.

On August 30, 2017 the US Food and Drug Administration approved tisagenlecleucel (Kymriah; Novartis, Basel, Switzerland), a synthetic bioimmune product of anti-CD19 chimeric antigen receptor T cells (CAR-T), for the treatment of children and young adults with relapsed/refractory B cell acute lymphoblastic leukemia (B-ALL). With this new era of personalized cancer immunotherapy, multiple challenges are present, ranging from implementation of a CAR-T program to safe delivery of the drug, long-term toxicity monitoring, and disease assessments. To address these issues experts representing the American Society for Blood and Marrow Transplant, the European Society for Blood and Marrow Transplantation, the International Society of Cell and Gene Therapy, and the Foundation for the Accreditation of Cellular Therapy formed a global CAR-T task force to identify and address key questions pertinent for hematologists and transplant physicians regarding the clinical use of anti CD19 CAR-T therapy in patients with B-ALL. This article presents an initial roadmap for navigating common clinical practice scenarios that will become more prevalent now that the first commercially available CAR-T product for B-ALL has been approved.

Reversal of Low Donor Chimerism after Hematopoietic Cell Transplantation Using Pentostatin and Donor Lymphocyte Infusion: A Prospective Phase II Multicenter Trial.

In a multicenter, prospective, phase II study we evaluated the safety and efficacy of pentostatin followed by donor lymphocyte infusion (DLI) in patients with low donor Tcell chimerism after allogeneic hematopoietic cell transplantation (HCT). Thirty-six patients with low donor blood CD3 chimerism were enrolled in this study. Thirty-five patients received a total of 41 DLIs after a dose of pentostatin, and 1 patient received pentostatin only. Median donor CD3 chimerism prompting the initiation of pentostatin and DLI was 28% (range, 5% to 47%). Responses (defined by increases in donor CD3 chimerism ≥10% maintained to day 56 post-DLI) were seen in 16 patients (44.4%) with a median rise in CD3 donor chimerism to 64% (range, 48% to 100%). There was a trend for better responses among 21 patients who received first treatment within 100 days after transplant (57% response rate) compared with15 patients who received first treatment more than 100 days after HCT (27% response rate, P = .07). Fourteen patients (39%) developed grades II to IV acute graft-versus-host disease (GVHD) at a median of 10 days (range, 0 to 83) after DLI. Ten patients (28%) developed extensive chronic GVHD. Seventeen patients (47%) developed new grade 4 cytopenias after DLI. There was no difference in relapse between nonresponders and responders. Twenty-eight patients (78%) died, most (n = 21) because of relapse. Five of 16 responders (31%) are alive, all disease-free, at a median of 60 months (range, 21 to 132) after DLI. Six of 20 nonresponders (30%) are alive at a median of 47 months (range, 16 to 100) after DLI, 3 in complete remission. Pentostatin and DLI had acceptable toxicity and appeared to increase low donor CD3 chimerism after HCT but had no impact on mortality.

Quality of Life of Caregivers of Hematopoietic Cell Transplant Recipients.

Caregivers are critical to recipient recovery after hematopoietic cell transplant (HCT); however, little is known about their long-term health and quality of life (QoL). In this study we surveyed 4446 caregiver-recipient pairs in the post-HCT period to describe their QoL and its determinants. In total, 849 caregiver-recipient pairs at a median of 6 years after autologous or allogeneic HCT responded. Among 849 responding caregivers at a median of 6 years post-HCT, 67% of caregivers were women and 68% indicated they were still providing care to the recipient. Mean and median QoL measures of caregivers were at or above general population norms; however, approximately 20% of caregivers reported poor QoL relative to general population norms. Multivariate analysis revealed that caregiver characteristics, including age, gender, and educational attainment, were important determinants of caregiver QoL. Additional determinants of caregiver QoL included recipient QoL, relapse after autologous HCT, and ongoing use of immunosuppression after allogeneic HCT. Additionally, the prevalence of depression and sleep disorders appear to be higher in caregivers than in the general population. We have identified a population of caregivers who may benefit from interventions aimed at improving QoL and health outcomes. HCT clinical practice should also consider caregiver well-being.

Success of Immunosuppressive Treatments in Patients with Chronic Graft-versus-Host Disease.

Moderate to severe chronic graft-versus-host disease (GVHD) is treated with potent immunosuppressive therapy (IST) to modulate the allo-immune response, control symptoms, and prevent further organ damage. We sought to understand the types of treatments used in clinical practice and the likelihood of successful treatment associated with each. A chart review was performed for 250 adult patients at Fred Hutchinson Cancer Research Center enrolled in a prospective observational study. After a median follow-up of 5.6 years for survivors, approximately one-third were still on IST (of whom half were on fourth or greater line of therapy), one-third were alive and off IST, and one-third had relapsed or died. Approximately half of survivors stopped all IST at least once, although half of these restarted IST after a median of 3.4 months (interquartile range, 2.3 to 8.0) off therapy. Successful discontinuation of IST for at least 9 months was associated with myeloablative conditioning (P = .04), more years since transplant (P = .009), and lack of oral (P < .001) and skin (P = .049) involvement compared with those who had to restart IST. We conclude that patients with chronic GVHD usually receive multiple lines and years of IST, with only a third off IST, alive, and free of malignancy at 5 years after chronic GVHD diagnosis. Patients stopping IST should be cautioned to self-monitor and continue close medical follow-up, especially for 3 to 6 months after stopping IST.

Central nervous system involvement in acute myeloid leukemia patients undergoing hematopoietic cell transplantation.

Knowledge regarding the rate of central nervous system (CNS) involvement and risk factors for its development in acute myeloid leukemia (AML) patients undergoing allogeneic hematopoietic cell transplantation (HCT) are limited. In this study we retrospectively evaluated CNS involvement in 327 patients who underwent myeloablative HCT at our institute in which all patients have cerebrospinal fluid examined by morphology or flow cytometry before HCT. Twenty-two patients (7%) had CNS AML involvement at pre-HCT evaluation. Covariates associated with such involvement were higher WBC at diagnosis, prior CNS or other extramedullary disease, and evidence of systemic disease at pre-HCT evaluation. History of prior CNS disease and disease status at pre-HCT evaluation allowed stratification of patients into 3 risk groups: 35% (20 patients), 16% (51 patients), and 3% (256 patients) rates of pre-HCT CNS involvement. Treatment of pre-HCT CNS disease was uniformly successful regardless of whether cranial irradiation therapy was used. Perhaps as a result, presence of CNS pre-HCT had no independent influence on post-HCT outcome, which was primarily influenced by status of systemic disease at time of HCT.

Central nervous system relapse in adults with acute lymphoblastic leukemia after allogeneic hematopoietic stem cell transplantation.

Central nervous system (CNS) relapse after allogeneic hematopoietic stem cell transplantation (HSCT) confers a poor prognosis in adult patients with acute lymphoblastic leukemia (ALL). Preventing CNS relapse after HSCT remains a therapeutic challenge, and criteria for post-HSCT CNS prophylaxis have not been addressed. In a 3-center retrospective analysis, we reviewed the data for 457 adult patients with ALL who received a first allogeneic HSCT in first or second complete remission (CR). All patients received CNS prophylaxis as part of their upfront therapy for ALL, but post-transplantation CNS prophylaxis practice varied by institution and was administered to 48% of the patients. Eighteen patients (4%) developed CNS relapse after HSCT (isolated CNS relapse, n = 8; combined bone marrow and CNS relapse, n = 10). Patients with a previous history of CNS involvement with leukemia had a significantly higher rate for CNS relapse (P = .002), and pretransplantation CNS involvement was the only risk factor for post-transplantation CNS relapse found in this study. We failed to find a significant effect of post-transplantation CNS prophylaxis to prevent relapse after transplantation. Furthermore, no benefit for post-transplantation CNS prophylaxis could be detected when a subgroup analysis of patients with (P = .10) and without previous CNS involvement (P = .52) was performed. Finally, we could not find any significant effect for intensity of the transplantation conditioning regimen on CNS relapse after HSCT. In conclusion, CNS relapse is an uncommon event after HSCT for patients with ALL in CR1 or CR2, but with higher risk among patients with CNS involvement before transplantation. Furthermore, neither the use of post-HSCT CNS prophylaxis nor the intensity of the HSCT conditioning regimen made a significant difference in the rate of post-HSCT CNS relapse.

Treosulfan, fludarabine, and 2-Gy total body irradiation followed by allogeneic hematopoietic cell transplantation in patients with myelodysplastic syndrome and acute myeloid leukemia.

Allogeneic hematopoietic cell transplantation (HCT) offers curative therapy for many patients with myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). However, post-HCT relapse remains a major problem, particularly in patients with high-risk cytogenetics. In this prospective phase II trial, we assessed the efficacy and toxicity of treosulfan, fludarabine, and 2 Gy total body irradiation (TBI) as conditioning for allogeneic HCT in patients with MDS or AML. Ninety-six patients with MDS (n = 36: 15 refractory cytopenia with multilineage dysplasia, 10 refractory anemia with excess blasts type 1, 10 refractory anemia with excess blasts type 2, 1 chronic myelomonocytic leukemia type 1) or AML (n = 60: 35 first complete remission [CR], 18 second CR, 3 advanced CR, 4 refractory relapse) were enrolled; median age was 51 (range, 1 to 60) years. Twelve patients had undergone a prior HCT with high-intensity conditioning. Patients received 14 g/m(2)/day treosulfan i.v. on days -6 to -4, 30 mg/m(2)/day fludarabine i.v. on days -6 to -2, and 2 Gy TBI on day 0, followed by infusion of hematopoietic cells from related (n = 27) or unrelated (n = 69) donors. Graft-versus-host disease prophylaxis consisted of tacrolimus and methotrexate. With a median follow-up of 30 months, the 2-year overall survival (OS), relapse incidence, and nonrelapse mortality were 73%, 27%, and 8%, respectively. The incidences of grades II to IV (III to IV) acute and chronic graft-versus-host disease were 59% (10%) and 47%, respectively. Two-year OS was not significantly different between MDS patients with poor-risk and good/intermediate-risk cytogenetics (69% and 85%, respectively) or between AML patients with unfavorable and favorable/intermediate-risk cytogenetics (64% and 76%, respectively). In AML patients, minimal residual disease (MRD; n = 10) at the time of HCT predicted higher relapse incidence (70% versus 18%) and lower OS (41% versus 79%) at 2 years, when compared with patients without MRD. In conclusion, treosulfan, fludarabine, and low-dose TBI provided effective conditioning for allogeneic HCT in patients with MDS or AML and resulted in low relapse incidence, regardless of cytogenetic risk. In patients with AML, MRD at the time of HCT remained a risk factor for post-HCT relapse.

Informing the Recommended Phase III Dose of Alnuctamab, a CD3 × BCMA T-Cell Engager, Using Population Pharmacokinetics and Exposure-Response Analysis.

Alnuctamab, a B-cell maturation antigen (BCMA)-targeting T-cell engager, has demonstrated encouraging antitumor activity in the phase I study CC-93269-MM-001 treating patients with relapsed or refractory multiple myeloma. Identification of a recommended Phase III dose (RP3D) was a key objective, as such population pharmacokinetic (PopPK) and exposure-response analysis was critical. Intravenous (IV) alnuctamab was administered in fixed doses (0.15-10 mg) or in step-up doses to a maximum 10-mg target dose. Subcutaneous (SC) step-up doses of 3 and 6 mg were followed by a target dose range of 10-60 mg. Concentration data from IV and SC alnuctamab administration was pooled and was well described by a two-compartment PopPK model with first-order absorption and elimination. Covariate analysis determined that the inclusion of baseline soluble BCMA (sBCMA) on clearance significantly improved model fitting. Individual exposure parameters were estimated from the final model to characterize exposure-response relationships. Switching from IV to SC administration improved the safety profile of alnuctamab by limiting the frequency of grade ≥2 CRS events. A significant exposure-CRS relationship was observed after the first SC dose, but not subsequent dose administrations. Exposure-safety analysis did not find a statistically significant relationship between increasing exposure and the probability of key safety events of interest. Logistic regression analysis for patients administered SC alnuctamab identified that increased exposure significantly increased the probability of response, although the additional benefit was minimal at exposures above 30 mg target dose. Considering the totality of exposure-response data, the clinical pharmacology assessment supported a SC RP3D of 3/6/30 mg.

Nivolumab, Pomalidomide, and Elotuzumab Combination Regimens for Treatment of Relapsed and Refractory Multiple Myeloma: Results from the Phase 3 CheckMate 602 Study.

BACKGROUND: Preclinical studies suggest that combining nivolumab, a programmed death-1 (PD-1) immune checkpoint inhibitor, with pomalidomide/dexamethasone (Pd) with or without elotuzumab, an antisignaling lymphocytic activation molecule F7 monoclonal antibody, may improve multiple myeloma (MM) treatment efficacy. PATIENTS AND METHODS: The phase 3 CheckMate 602 study (NCT02726581) assessed the efficacy and safety of nivolumab plus pomalidomide/dexamethasone (NPd) and NPd plus elotuzumab (NE-Pd). Eligible patients (aged ≥ 18 years) had measurable MM after ≥ 2 prior lines of therapy, that included an immunomodulatory drug (IMiD) and proteasome inhibitor (PI), each for ≥ 2 consecutive cycles, alone or combined, and were refractory to their last line of therapy. Patients were randomized 3:3:1 to receive NPd, Pd, or NE-Pd. The primary endpoint was progression-free survival (PFS); overall response rate (ORR) was a key secondary endpoint. RESULTS: At a median follow-up of 16.8 months, PFS was similar between treatment arms (Pd, 7.3 months [95% CI, 6.5-8.4]; NPd, 8.4 months [95% CI, 5.8-12.1]; NE-Pd, 6.3 months [95% CI, 2.4-11.1]). ORR was similar in the Pd (55%), NPd (48%), and NE-Pd (42%) arms. Nivolumab-containing arms were associated with a less favorable safety profile versus Pd, including a higher rate of thrombocytopenia (NPd, 25.0%; NE-Pd, 16.7%; Pd, 15.7%), any-grade immune-mediated adverse events (NPd, 13.9%; NE-Pd, 16.7%; Pd, 2.9%), and adverse events leading to discontinuation (NPd, 25.0%; NE-Pd, 33.3%; Pd, 18.6%). No new safety signals were identified. CONCLUSION: CheckMate 602 did not demonstrate clinical benefit of nivolumab (+/- elotuzumab) plus Pd versus Pd for patients with relapsed/refractory MM (RRMM).

Donor lymphocyte infusion for relapsed hematological malignancies after allogeneic hematopoietic cell transplantation: prognostic relevance of the initial CD3+ T cell dose.

The impact of donor lymphocyte infusion (DLI) initial cell dose on its outcome is known in patients with chronic myeloid leukemia but limited in patients with other hematological malignancies. In this retrospective study, we evaluated the effect of initial DLI CD3(+) cell dose on graft-versus-host disease (GVHD) and overall survival after DLI given for relapse of any hematological malignancies after allogeneic hematopoietic cell transplantation (HCT) with high- or reduced-intensity conditioning. The cohort included 225 patients. Initial DLI CD3(+) cell dose per kilogram of recipient body weight was ≤ 1 × 10(7) (n = 84; group A), >1.0 to <10 × 10(7) (n = 58; group B), and ≥ 10 × 10(7) (n = 66; group C). The initial cell dose was unknown for the remaining 17 patients. Cumulative incidence rates of GVHD at 12 months after DLI were 21%, 45%, and 55% for groups A, B, and C, respectively. Multivariate analysis showed that initial DLI CD3(+) cell ≥ 10 × 10(7) dose per kilogram is associated with an increased risk of GVHD after DLI (P = .03). Moreover, an initial DLI CD3(+) cell dose of 10 × 10(7) or higher did not decrease the risk of relapse and did not improve overall survival. Thus, these results support the use of less than 10 × 10(7) CD3(+) cell per kilogram as the initial cell dose of DLI for treatment of persistent or recurrent hematological malignancy after HCT.

Maintenance therapy with tyrosine kinase inhibitors after transplant in patients with chronic myeloid leukemia.

Because of their outstanding efficacy and low toxicity, tyrosine kinase inhibitors (TKIs) have replaced allogeneic hematopoietic cell transplant (HCT) as the standard frontline therapy for patients with newly diagnosed chronic myeloid leukemia (CML). Until a decade ago, HCT was the preferred treatment for CML, with 5-year overall survival rates of approximately 80%, 40%, and 20% for patients in chronic, accelerated, and blast crisis phases, respectively. Relapse after transplant is a problem for patients who undergo transplant in advanced phase disease and those undergoing a T-depleted transplant. Until the introduction of TKIs, therapy for relapsed CML after transplant relied on interferon and/or donor leukocyte infusion (DLI). Although effective in inducing remission, DLI is associated with clinically significant graft-versus-host disease or myelosuppression, with an accompanying treatment-related mortality of 5% to 20%. TKIs have emerged as an attractive alternative therapy for persistent or relapsing CML after HCT. Similar to DLI, the effectiveness of TKI posttransplant is largely determined by the phase of disease at relapse, showing very good response in patients experiencing relapse in the chronic phase, with high rates (>60%) of hematologic and cytogenetic remissions, but less favorable outcomes in patients with advanced disease, with only a minority experiencing durable cytogenetic or molecular remissions. Molecular monitoring of the BCR-ABL chimeric mRNA posttransplant is important for early detection of patients at high risk of relapse.

Severe cytokine release syndrome is associated with hematologic toxicity following CD19 CAR T-cell therapy.

CD19-targeted chimeric antigen receptor (CAR) T-cell therapy has demonstrated remarkable efficacy in patients with relapsed/refractory B-cell malignancies; however, it is associated with toxicities including cytokine release syndrome (CRS), neurotoxicity, and impaired hematopoietic recovery. The latter is associated with high-grade cytopenias requiring extended growth factor or transfusional support, potentially leading to additional complications such as infection or hemorrhage. To date, the factors independently associated with hematologic toxicity have not been well characterized. To address this deficit, we retrospectively analyzed 173 patients who received defined-composition CD19 CAR T-cell therapy in a phase 1/2 clinical trial (https://clinicaltrials.gov; NCT01865617), with primary end points of absolute neutrophil count and platelet count at day-28 after CAR T-cell infusion. We observed cumulative incidences of neutrophil and platelet recovery of 81% and 75%, respectively, at 28 days after infusion. Hematologic toxicity was noted in a significant subset of patients, with persistent neutropenia in 9% and thrombocytopenia in 14% at last follow-up. Using debiased least absolute shrinkage selector and operator regression analysis for high-dimensional modeling and considering patient-, disease-, and treatment-related variables, we identified increased CRS severity as an independent predictor for decreased platelet count and lower prelymphodepletion platelet count as an independent predictor of both decreased neutrophil and platelet counts after CD19 CAR T-cell infusion. Furthermore, multivariable models including CRS-related cytokines identified associations between higher peak serum concentrations of interleukin-6 and lower day-28 cell counts; in contrast, higher serum concentrations of transforming growth factor-ß1 were associated with higher counts. Our findings suggest that patient selection and improved CRS management may improve hematopoietic recovery after CD19 CAR T-cell therapy.