Novel immunotherapies are increasingly being employed in pediatric oncology, both in the upfront and relapsed/refractory settings. Through various mechanisms of action, engagement and activation of ...the immune system can cause both generalized and disease site-specific inflammation, leading to immune-related adverse events (irAEs). One of the most worrisome irAEs is that of neurotoxicity. This can present as a large spectrum of neurological toxicities, including confusion, aphasia, neuropathies, seizures, and/or death, with variable onset and severity. Earlier identification and treatment, generally with corticosteroids, remains the mainstay of neurotoxicity management to optimize patient outcomes. The pathophysiology of neurotoxicity varies across the different therapeutic strategies and remains to be elucidated in most cases. Furthermore, little is known about long-term neurologic sequelae. This review will focus on neurotoxicity seen with the most common immunotherapies used in pediatric oncology, including CAR T cell therapy, alternative forms of adoptive cell therapy, antibody therapies, immune checkpoint inhibitors, and tumor vaccines. Herein we will discuss the incidence, pathophysiology, symptomatology, diagnosis, and management strategies currently being utilized for immunotherapy-associated neurotoxicity with a focus on pediatric specific considerations.
Children's Oncology Group trial AALL1621 was conducted to prospectively determine the safety and efficacy of inotuzumab ozogamicin (InO) in pediatric and adolescent patients with relapsed or ...refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL).
This single-arm phase II trial enrolled patients age 1-21 years with R/R CD22-positive B-ALL. In cycle 1, InO dosing was 0.8 mg/m
intravenously on day 1 and 0.5 mg/m
on days 8 and 15 of a 28-day cycle with response evaluation at day 28. Using a two-stage design, the trial was continuously monitored for dose-limiting toxicities and sinusoidal obstruction syndrome (SOS). CD22 expression was retrospectively evaluated by central flow cytometry.
Forty-eight patients were evaluable for response and toxicity; 19 had complete response (CR) and nine CR with incomplete count recovery (CRi) after cycle 1 (CR/CRi rate: 58.3%; two-sided 90% CI, 46.5 to 69.3). Twenty-seven of 28 patients with CR or CRi had minimal residual disease measured by flow cytometry; 18 (66.7%) had minimal residual disease < 0.01%. Seven of 28 patients (25%) with CR or CRi had delayed count recovery past day 42 in cycle 1. Three (6.3%) patients had grade 3 ALT elevation and one patient had grade 3 hyperbilirubinemia in cycle 1. Of 21 patients undergoing hematopoietic stem-cell transplantation after InO, 6 (28.6%) developed grade 3 SOS. Partial CD22 expression and lower CD22 site density were associated with lower likelihood of response to InO.
InO is effective and well tolerated in heavily pretreated children and adolescents with R/R CD22-positive B-ALL. SOS after hematopoietic stem-cell transplantation and prolonged cytopenias were notable. CD22 modulation was identified as a mechanism of resistance. Expanded study of InO combined with chemotherapy is underway.
Natural killer (NK) cells can enhance engraftment and mediate graft-versus-leukemia following allogeneic hematopoietic stem cell transplantation (HSCT), but the potency of graft-versus-leukemia ...mediated by naturally reconstituting NK cells following HSCT is limited. Preclinical studies demonstrate that activation of NK cells using interleukin-15 (IL-15) plus 4-1BBL upregulates activating receptor expression and augments killing capacity. In an effort to amplify the beneficial effects of NK cells post-HSCT, we conducted a first-in-human trial of adoptive transfer of donor-derived IL-15/4-1BBL–activated NK cells (aNK-DLI) following HLA-matched, T-cell–depleted (1-2 × 104 T cells/kg) nonmyeloablative peripheral blood stem cell transplantation in children and young adults with ultra-high-risk solid tumors. aNK-DLI were CD3+-depleted, CD56+-selected lymphocytes, cultured for 9 to 11 days with recombinant human IL-15 plus 4-1BBL+IL-15Rα+ artificial antigen-presenting cells. aNK-DLI demonstrated potent killing capacity and displayed high levels of activating receptor expression. Five of 9 transplant recipients experienced acute graft-versus-host disease (GVHD) following aNK-DLI, with grade 4 GVHD observed in 3 subjects. GVHD was more common in matched unrelated donor vs matched sibling donor recipients and was associated with higher donor CD3 chimerism. Given that the T-cell dose was below the threshold required for GVHD in this setting, we conclude that aNK-DLI contributed to the acute GVHD observed, likely by augmenting underlying T-cell alloreactivity. This trial was registered at www.clinicaltrials.gov as #NCT01287104.
•Acute GVHD occurred in 5 of 9 patients after major histocompatibility–matched, T-cell–depleted peripheral blood stem cell transplantation plus IL-15/4-1BBL aNK-DLI.•GVHD was more common in matched unrelated donor transplants and associated with higher CD3 chimerism, suggesting that aNK-DLI may augment T-cell alloreactivity.
As clinical applications for chimeric antigen receptor T cell (CART) therapy extend beyond early phase trials, commercial manufacture incorporating cryopreservation steps becomes a logistical ...necessity. The effect of cryopreservation on CART characteristics is unclear. We retrospectively evaluated the effect of cryopreservation on product release criteria and in vivo characteristics in 158 autologous CART products from 6 single-center clinical trials. Further, from 3 healthy donor manufacturing runs, we prospectively identified differentially expressed cell surface markers and gene signatures among fresh versus cryopreserved CARTs. Within 2 days of culture initiation, cell viability of the starting fraction (peripheral blood mononuclear cells PBMNCs) decreased significantly in the cryo-thawed arm compared to the fresh arm. Despite this, PBMNC cryopreservation did not affect final CART fold expansion, transduction efficiency, CD3%, or CD4:CD8 ratios. In vivo CART persistence and clinical responses did not differ among fresh and cryopreserved final products. In healthy donors, compared to fresh CARTs, early apoptotic cell-surface markers were significantly elevated in cryo-thawed CARTs. Cryo-thawed CARTs also demonstrated significantly elevated expression of mitochondrial dysfunction, apoptosis signaling, and cell cycle damage pathways. Cryopreservation during CART manufacture is a viable strategy, based on standard product release parameters. The clinical impact of cryopreservation-related subtle micro-cellular damage needs further study.
Panch et al. demonstrate that CART cryopreservation during manufacture minimally affects final product characteristics, in vivo levels, persistence, and clinical response. However, increases in early apoptotic markers and cell damage pathways in cryo-thawed CARTs require careful consideration to better formulate dosing strategies.
Summary
GATA2 deficiency was described in 2011, and shortly thereafter allogeneic hematopoietic stem cell transplantation (HSCT) was shown to reverse the hematologic disease phenotype. However, there ...remain major unanswered questions regarding the type of conditioning regimen, type of donors, and graft‐versus‐host disease (GVHD) prophylaxis. We report 59 patients with GATA2 mutations undergoing HSCT at National Institutes of Health between 2013 and 2020. Primary endpoints were engraftment, reverse of the clinical phenotype, secondary endpoints were overall survival (OS), event‐free survival (EFS), and the incidence of acute and chronic GVHD. The OS and EFS at 4 years were 85·1% and 82·1% respectively. Ninety‐six percent of surviving patients had reversal of the hematologic disease phenotype by one‐year post‐transplant. Incidence of grade III‐IV aGVHD in matched related donor (MRD) and matched unrelated donor recipients (URD) patients receiving Tacrolimus/Methotrexate for GVHD prophylaxis was 32%. In contrast, in the MRD and URD who received post‐transplant cyclophosphamide (PT/Cy), no patient developed grade III‐IV aGVHD. Six percent of haploidentical related donor (HRD) recipients developed grade III‐IV aGVHD. In summary, a busulfan‐based HSCT regimen in GATA2 deficiency reverses the hematologic disease phenotype, and the use of PT/Cy reduced the risk of both aGVHD and cGVHD.
Clinical CAR T-cell therapy using integrating vector systems represents a promising approach for the treatment of hematological malignancies. Lentiviral and γ-retroviral vectors are the most commonly ...used vectors in the manufacturing process. However, the integration pattern of these viral vectors and subsequent effect on CAR T-cell products is still unclear.
We used a modified viral integration sites analysis (VISA) pipeline to evaluate viral integration events around the whole genome in pre-infusion CAR T-cell products. We compared the differences of integration pattern between lentiviral and γ-retroviral products. We also explored whether the integration sites correlated with clinical outcomes.
We found that γ-retroviral vectors were more likely to insert than lentiviral vectors into promoter, untranslated, and exon regions, while lentiviral vector integration sites were more likely to occur in intron and intergenic regions. Some integration events affected gene expression at the transcriptional and post-transcriptional level. Moreover, γ-retroviral vectors showed a stronger impact on the host transcriptome. Analysis of individuals with different clinical outcomes revealed genes with differential enrichment of integration events. These genes may affect biological functions by interrupting amino acid sequences and generating abnormal proteins, instead of by affecting mRNA expression. These results suggest that vector integration is associated with CAR T-cell efficacy and clinical responses.
We found differences in integration patterns, insertion hotspots and effects on gene expression vary between lentiviral and γ-retroviral vectors used in CAR T-cell products and established a foundation upon which we can conduct further analyses.
Immune‐effector cell‐associated neurotoxicity syndrome (ICANS) is a significant toxicity occurring with chimeric antigen receptor (CAR) T‐cell therapy, with first‐line treatment options including ...supportive care and systemic corticosteroids. Sparse data exist on how to approach progressive/refractory cases of ICANS. We present five pediatric and young adult patients with relapsed/refractory B‐cell acute lymphoblastic leukemia (ALL) who had progressively worsening ICANS despite systemic steroids, and received intrathecal hydrocortisone with rapid reversal of ICANS. Therapeutic lumbar punctures are routinely used in upfront ALL therapy in pediatrics, with a demonstrable safety profile, thus use of intrathecal hydrocortisone merits further prospective studies in patients with severe ICANS.
Remission durability following single-antigen targeted chimeric antigen receptor (CAR) T-cells is limited by antigen modulation, which may be overcome with combinatorial targeting. Building upon our ...experiences targeting CD19 and CD22 in B-cell acute lymphoblastic leukemia (B-ALL), we report on our phase 1 dose-escalation study of a novel murine stem cell virus (MSCV)-CD19/CD22-4-1BB bivalent CAR T-cell (CD19.22.BBζ) for children and young adults (CAYA) with B-cell malignancies. Primary objectives included toxicity and dose finding. Secondary objectives included response rates and relapse-free survival (RFS). Biologic correlatives included laboratory investigations, CAR T-cell expansion and cytokine profiling. Twenty patients, ages 5.4 to 34.6 years, with B-ALL received CD19.22.BBζ. The complete response (CR) rate was 60% (12 of 20) in the full cohort and 71.4% (10 of 14) in CAR-naïve patients. Ten (50%) developed cytokine release syndrome (CRS), with 3 (15%) having ≥ grade 3 CRS and only 1 experiencing neurotoxicity (grade 3). The 6- and 12-month RFS in those achieving CR was 80.8% (95% confidence interval CI: 42.4%-94.9%) and 57.7% (95% CI: 22.1%-81.9%), respectively. Limited CAR T-cell expansion and persistence of MSCV-CD19.22.BBζ compared with EF1α-CD22.BBζ prompted laboratory investigations comparing EF1α vs MSCV promoters, which did not reveal major differences. Limited CD22 targeting with CD19.22.BBζ, as evaluated by ex vivo cytokine secretion and leukemia eradication in humanized mice, led to development of a novel bicistronic CD19.28ζ/CD22.BBζ construct with enhanced cytokine production against CD22. With demonstrated safety and efficacy of CD19.22.BBζ in a heavily pretreated CAYA B-ALL cohort, further optimization of combinatorial antigen targeting serves to overcome identified limitations (www.clinicaltrials.gov #NCT03448393).
•CD19.22.BBζ CAR T cells were well tolerated and effective in pediatric B-ALL, but persistence and CD22 targeting were limited.•A novel bicistronic CD19.28ζ/CD22.BBζ CAR T-cell enhanced dual-targeting efficacy and cytokine production in preclinical models.
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Improving CAR T-cells: The next generation Marple, Andrew H; Bonifant, Challice L; Shah, Nirali N
Seminars in hematology,
07/2020, Letnik:
57, Številka:
3
Journal Article
Recenzirano
The introduction of chimeric antigen receptor (CAR) T-cell therapy in acute lymphoblastic leukemia (ALL) has dramatically altered the landscape of treatment options available to children and adults ...with ALL. With complete remission induction rates exceeding 70% in most trials and FDA approval of one CD19 CAR T-cell construct in ALL, CAR T-cell therapy has become a mainstay in the ALL treatment algorithm for those with relapsed/refractory disease. Despite the high remission induction rate, with growing experience using CAR T-cell therapy in ALL, a host of barriers to maintaining long-term durable remissions have been identified. Specifically, relapse after, resistance to, or loss of long-term CAR T-cell persistence may all hinder CAR T-cell efficacy. In this review, we provide an overview of the current limitations which inform the design of the next generation of CAR T-cells and discuss advances in CAR T-cell engineering aimed to improve upon outcomes with CAR T-cell-based therapy in ALL.
Women in immunology: 2020 and beyond Pierce, Susan K; Schwartzberg, Pamela L; Shah, Nirali N ...
Nature immunology,
03/2020, Letnik:
21, Številka:
3
Journal Article
Recenzirano
Women have been at the forefront of tremendous achievements in immunology in the past decade. However, disparities still exist, limiting upward potential and further advancements. As four NIH ...intramural women scientists who care deeply about scientific progress and the progress of women in our field, we review ongoing challenges and discuss potential approaches to help advance the promotion of women in the sciences.
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