BackgroundBecause of their well-described immunosuppressive properties, allogeneic adult human mesenchymal stromal cells (MSC) derived from bone marrow have demonstrated safety and efficacy in ...steroid refractory acute graft versus host disease (SR aGVHD). Clinical trials have resulted in variable success and an optimal source of MSC has yet to be defined. Based on the importance of maternal-fetal interface immune tolerance, extraembryonic fetal tissues, such as the umbilical cord, may provide an superior tissue source of MSC to mediate immunomodulation in aGVHD.MethodsA two-dose cohort trial allogeneic Wharton’s Jelly-derived mesenchymal stromal cells (WJMSC, referred to as MSCTC-0010, here) were tested in 10 patients with de novo high risk (HR) or SR aGVHD post allogeneic hematopoietic stem cell transplantation (allo-HCT). Following Good Manufacturing Practices isolation, expansion and cryostorage, WJMSC were thawed and administered via intravenous infusions on days 0 and 7 at one of two doses (low dose cohort, 2 × 106/kg, n = 5; high dose cohort, 10 × 106/kg, n = 5). To evaluate safety, patients were monitored for infusion related toxicity, Treatment Related Adverse Events (TRAE) til day 42, or ectopic tissue formation at day 90. Clinical responses were monitored at time points up to 180 days post infusion. Serum biomarkers ST2 and REG3α were acquired 1 day prior to first MSCTC-0010 infusion and on day 14.ResultsSafety was indicated, e.g., no infusion-related toxicity, no development of TRAE, nor ectopic tissue formation in either low or high dose cohort was observed. Clinical response was suggested at day 28: the overall response rate (ORR) was 70%, 4 of 10 patients had a complete response (CR) and 3 had a partial response (PR). By study day 90, the addition of escalated immunosuppressive therapy was necessary in 2 of 9 surviving patients. Day 100 and 180 post infusion survival was 90% and 60%, respectively. Serum biomarker REG3α decreased, particularly in the high dose cohort, and with REG3α decrease correlated with clinical response.ConclusionsTreatment of patients with de novo HR or SR aGVHD with low or high dose MSCTC-0010 was safe: the infusion was well-tolerated, and no TRAEs or ectopic tissue formation was observed. A clinical improvement was seen in about 70% patients, with 4 of 10 showing a complete response that may have been attributable to MSCTC-0010 infusions. These observations indicate safety of two different doses of MSCTC-0010, and suggest that the 10 × 106 cells/ kg dose be tested in an expanded randomized, controlled Phase 2 trial.
Acute myeloid leukemia (AML) is a complex diagnosis that puts patients at a higher risk for developing infections, particularly invasive fungal infections (IFI). Mutations in
have been shown to cause ...dysfunction in B-cell homeostasis and differentiation, making it a risk factor for developing immunodeficiency syndromes. In this case, a male patient in his 40s presented to our emergency department (ED) with symptoms leading to a diagnosis of AML with concurrent mucormycosis of the lungs and sinuses. Targeted next generation sequencing (NGS) of the patient's bone marrow showed, among other variants, a loss of function mutation in the
gene. While most patients present with fungal infections after prolonged periods of neutropenia associated with AML treatment, this case presented with IFI at diagnosis without neutropenia suggesting an immunodeficiency syndrome. The concurrent IFI and AML diagnoses create a delicate balance between treatment of the infection and the malignancy. This case highlights the risk of infection in patients receiving chemotherapy, especially those with unrecognized immunodeficiency syndromes, and emphasizes the importance of NGS for prognosis and treatment.
Graft versus host disease (GVHD) represents a major complication of allogeneic hematopoietic stem cell transplantation (allo HCT). Graft cellular manipulation has been used to mitigate the risk of ...GVHD. The αβ T cells are considered the primary culprit for causing GVHD therefore depletion of this T cell subset emerged as a promising cellular manipulation strategy to overcome the human leukocyte antigen (HLA) barrier of haploidentical (haplo) HCT. This approach is also being investigated in HLA-matched HCT. In several studies, αβ T cell depletion HCT has been performed without pharmacologic GVHD prophylaxis, thus unleashing favorable effect of donor's natural killer cells (NK) and γδ T cells. This article will discuss the evolution of this method in clinical practice and the clinical outcome as described in different clinical trials.
Background
The first-in-class approved BCMA CAR-T therapy was idecabtagene vicleucel (ide-cel), approved in March 2021, for RRMM patients who progressed after 4 or more lines of therapy. Despite the ...promising outcomes, there were limited apheresis/production slots for ide-cel. We report outcomes of patients at our institution who were on the “waitlist” to receive ide-cel in 2021 and who could not secure a slot.
Methods
We conducted a retrospective review of RRMM patients evaluated at the University of Kansas Cancer Center for ide-cel from 3/2021-7/2021. A retrospective chart review was performed to determine patient and disease characteristics. Descriptive statistics were reported using medians for continuous variables. Survival analysis from initial consult was performed using Kaplan-Meier Survival estimator.
Results
Forty patients were eligible and were on the “waitlist” for CAR-T. The median follow-up was 14 months (2-25mo). Twenty-four patients (60%) secured a production slot and 16 (40%) did not. The median time from consult to collection was 38 days (8-703). The median time from collection to infusion was 42 days (34-132 days). The median overall survival was higher in the CAR-T group (NR vs 9 mo, p<0.001).
Conclusion(s)
Many patients who were eligible for ide-cel were not able to secure a timely slot in 2021. Mortality was higher in this group, due to a lack of comparable alternatives. Increasing alternate options as well as improvement in manufacturing and access is an area of high importance to improve RRMM outcomes.
Both mesenchymal stem cells (MSCs) and their corresponding small extracellular vesicles (sEVs, commonly referred to as exosomes) share similar immunomodulatory properties that are potentially ...beneficial for the treatment of acute graft versus host disease (aGvHD). We report that clinical grade Wharton's Jelly‐derived MSCs (WJMSCs) secrete sEVs enriched in programmed death‐ligand 1 (PD‐L1), an essential ligand for an inhibitory immune checkpoint. A rapid increase in circulating sEV‐associated PD‐L1 was observed in patients with aGvHD and was directly associated with the infusion time of clinical grade WJMSCs. In addition, in vitro inhibitory antibody mediated blocking of sEV‐associated PD‐L1 restored T cell activation (TCA), suggesting a functional inhibitory role of sEVs‐PD‐L1. PD‐L1‐deficient sEVs isolated from WJMSCs following CRISPR‐Cas9 gene editing fail to inhibit TCA. Furthermore, we found that PD‐L1 is essential for WJMSC‐derived sEVs to modulate T cell receptors (TCRs). Our study reveals an important mechanism by which therapeutic WJMSCs modulate TCR‐mediated TCA through sEVs or sEV‐carried immune checkpoints. In addition, our clinical data suggest that sEV‐associated PD‐L1 may be not only useful in predicting the outcomes from WJMSC clinical administration, but also in developing cell‐independent therapy for aGvHD patients.
BackgroundTumor-infiltrating lymphocyte (TIL) therapy is a personalized cancer treatment which involves generating ex vivo cultures of tumor-reactive T cells from surgically resected tumors and ...administering the expanded TILs as a therapeutic infusion. Phase 1 of many TIL production protocols use aldesleukin (IL-2) alone to establish TIL cultures (termed “PreREP” (Pre-Rapid Expansion Protocol)); however, this fails to consistently produce TIL cultures from renal cell carcinoma (RCC) in a timely manner. Adding mitogenic stimulation via anti-CD3/anti-CD28 beads along with IL-2 to the fresh tumor digest (FTD) during TIL generation (termed “FTD+ beads”) increases successful TIL culture rates; however, T cells produced by this method may be suboptimal for adoptive transfer. We hypothesize that adherent cell depletion (ACD) before TIL expansion will produce a superior TIL product by removing the immunosuppressive signals originating from adherent tumor and stromal cells. Here we investigate if “panning,” a technique for ACD prior to TIL expansion, will impact the phenotype, functionality and/or clonality of ex vivo expanded RCC TILs.MethodsTumor specimens from 55 patients who underwent radical or partial nephrectomy at the University of Kansas Medical Center (KUMC) were used to develop the panning method and an additional 19 specimens were used to validate the protocol. Next-generation sequencing, immunohistochemistry/immunocytochemistry and flow cytometry were used during method development. The phenotype, functionality and clonality of autologous TILs generated in parallel by panning, PreREP, and FTD+ beads were assessed by flow cytometry, in vitro co-culture assays, and TCRB CDR3 sequencing.ResultsTIL cultures were successfully generated using the panning protocol from 15/16 clear cell, 0/1 chromophobe, and 0/2 papillary RCC samples. Significantly fewer regulatory (CD4+/CD25+/FOXP3+) (p=0.049, p=0.005), tissue-resident memory (CD8+/CD103+) (p=0.027, p=0.009), PD-1+/TIM-3+ double-positive (p=0.009, p=0.011) and TIGIT+ T cells (p=0.049, p=0.026) are generated by panning relative to PreREP and FTD+ beads respectively. Critically, a subset of TILs generated by panning were able to degranulate and/or produce interferon gamma in response to autologous tumor cells and the average tumor-reactive TIL yield was greatest when using the panning protocol.ConclusionsRemoving immunosuppressive adherent cells within an RCC digest prior to TIL expansion allow for the rapid production of tumor-reactive T cells with optimal characteristics for adoptive transfer.
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Background: The presence of measurable residual disease (MRD) preceding hematopoietic stem cell transplantation (HSCT) in acute myeloid leukemia (AML) is increasingly recognized ...as a risk factor for leukemic relapse and decreased survival. Over many years, attempts have been looking at developing tools to detect MRD; this includes multiparametric flow cytometry, quantitative polymerase chain reaction, and most recently, next-generation sequencing (NGS). NGS offers higher sensitivity and detection rate of disease-related gene mutations, thereby potentially improving disease outcomes. Our study sought to review the scientific literature that included NGS‐detected molecular MRD in patients with AML who underwent bone marrow transplantation. Methods: We performed a systematic search using PubMed, Google Scholar, EMBASE, and SCOPUS up until October 2020. Inclusion criteria included articles that reported the association between pre-HSCT MRD detected by NGS and post HSCT outcome in patients with AML. We extracted hazard ratios for the cumulative incidence of relapse (CIR), overall survival (OS) and leukemia free survival (LFS). A random-effect model was utilized to calculate the hazard ratio (HR) with a 95% confidence interval (CI). Results: Six studies met our inclusion criteria. Our meta-analysis showed that the detection of pre-transplant MRD by NGS was associated with increased risk of cumulative incidence of relapse (hazard ratio=2.5, CI= 1.6-3.9, with p-value <0.001) and decreased overall survival (hazard ratio=1.6, CI= 1.6-2.3, p-value 0.005). LFS was significantly higher in those who had negative MRD detection by NGS before transplantation (HR=1.9, CI= 1.3-2.8 with p-value 0.001). These results were independent of the cytogenetic risk of conditioning intensity. There was heterogeneity between our studies (I
2
= 53%, 52%, and 59% for CIR, OS, and LFS, respectively). Conclusions: The application of NGS to detect MRD is a strong predictor of outcome in patients with AML who are undergoing hematopoietic stem cell transplantation. NGS-detected MRD positive status prior to HSCT is indicative of a higher risk of relapse and decreased overall survival in this meta-analysis. Despite the limitations in our study, it demonstrates the value of MRD detection by NGS in HSCT recipients.
TPS9608 Background: Metastatic melanoma (MM) patients who have progressed following immune checkpoint inhibitors (ICI; anti–PD-1/CTLA-4 therapy) and targeted agents (BRAF/MEK inhibitors) have limited ...treatment options and dismal prognosis. An autologous tumor-infiltrating lymphocytes (TIL) therapy (LN-144, lifileucel) has demonstrated efficacy and durable responses in heavily pretreated advanced melanoma. In a phase II study of TIL therapy (lifileucel) with traditional lymphodepletion (LD), using fludarabine 25 mg/m2 for 5 days and cyclophosphamide (Cy) 60 mg/kg for 2 days, in 153 MM patients previously treated with ICI and BRAF/MEK inhibitors, an overall response rate (ORR) of 31% was noted, and the median duration of response (DOR) was not reached after 27.6 month follow up. We hypothesize that a reduced dose of Flu/Cy LD for TIL therapy will have similar TIL expansion and persistence post-infusion, resulting in similar efficacy with a reduced toxicity profile. Methods: Study NCT06151847 is a single-center, open-label phase II pilot trial evaluating the efficacy, in vivo persistence, and safety of TIL therapy after reduced dose Flu/Cy LD. Key inclusion criteria include unresectable or metastatic melanoma (stage IIIC-IV) with disease progression after one or more lines of therapy. Four of the 12 planned patients have been enrolled as of February 2, 2024. Central TIL manufacturing from at least a 1.5 cm tumor specimen involves ex vivo expansion through cell culture in the presence of the interleukin (IL)-2 and an anti-CD3 monoclonal antibody (1-150 x10 9 viable cells). Patients will receive an outpatient reduced-dose Flu/Cy LD regimen of Flu (30 mg/m 2 on days -4, -3, -2, -1) and Cy (750 mg/m 2 on days -4, -3, -2). Infusion of TIL will be performed on day 0 followed by high-dose IL-2 (600,000 IU/kg up to 6 doses). The primary objective will be to ascertain TIL persistence using T-cell receptor (TCR) sequencing at day 42 which will be compared to historical data already generated utilizing traditional Flu/Cy LD. The secondary objectives will be to evaluate the efficacy parameters including ORR, DOR, progression-free survival (PFS), and overall survival (OS), and the safety profile of TIL in combination with a reduced dose Flu/Cy LD regimen. Exploratory objectives will involvecorrelative analyses to characterize the immunome and microenvironment. If TIL persistence is roughly equivocal between the reduced and high-dose Flu/Cy LD regimens, the design of a larger-scale trial using reduced-dose Flu/Cy LD for TIL therapy may be considered. Study follow-up will continue for one year. Clinical trial information: NCT06151847 .
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