Glioblastoma (GBM) is the most common primary malignant brain tumor in adults and is uniformly lethal. T-cell-based immunotherapy offers a promising platform for treatment given its potential to ...specifically target tumor tissue while sparing the normal brain. However, the diffuse and infiltrative nature of these tumors in the brain parenchyma may pose an exceptional hurdle to successful immunotherapy in patients. Areas of invasive tumor are thought to reside behind an intact blood brain barrier, isolating them from effective immunosurveillance and thereby predisposing the development of "immunologically silent" tumor peninsulas. Therefore, it remains unclear if adoptively transferred T cells can migrate to and mediate regression in areas of invasive GBM. One barrier has been the lack of a preclinical mouse model that accurately recapitulates the growth patterns of human GBM in vivo. Here, we demonstrate that D-270 MG xenografts exhibit the classical features of GBM and produce the diffuse and invasive tumors seen in patients. Using this model, we designed experiments to assess whether T cells expressing third-generation chimeric antigen receptors (CARs) targeting the tumor-specific mutation of the epidermal growth factor receptor, EGFRvIII, would localize to and treat invasive intracerebral GBM. EGFRvIII-targeted CAR (EGFRvIII+ CAR) T cells demonstrated in vitro EGFRvIII antigen-specific recognition and reactivity to the D-270 MG cell line, which naturally expresses EGFRvIII. Moreover, when administered systemically, EGFRvIII+ CAR T cells localized to areas of invasive tumor, suppressed tumor growth, and enhanced survival of mice with established intracranial D-270 MG tumors. Together, these data demonstrate that systemically administered T cells are capable of migrating to the invasive edges of GBM to mediate antitumor efficacy and tumor regression.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Isocitrate dehydrogenase (
)-mutant glioma is a distinct glioma molecular subtype for which no effective molecularly directed therapy exists. Low-grade gliomas, which are 80%-90%
-mutant, have high ...RNA levels of the cell surface Notch ligand DLL3. We sought to determine DLL3 expression by IHC in glioma molecular subtypes and the potential efficacy of an anti-DLL3 antibody-drug conjugate (ADC), rovalpituzumab tesirine (Rova-T), in
-mutant glioma.
We evaluated
expression by RNA using TCGA data and by IHC in a discovery set of 63 gliomas and 20 nontumor brain tissues and a validation set of 62 known
wild-type and mutant gliomas using a monoclonal anti-DLL3 antibody. Genotype was determined using a DNA methylation array classifier or by sequencing. The effect of Rova-T on patient-derived endogenous
-mutant glioma tumorspheres was determined by cell viability assay.
Compared to
wild-type glioblastoma,
-mutant gliomas have significantly higher
RNA (
< 1 × 10
) and protein by IHC (
= 0.0014 and
< 4.3 × 10
in the discovery and validation set, respectively). DLL3 immunostaining was intense and homogeneous in
-mutant gliomas, retained in all recurrent tumors, and detected in only 1 of 20 nontumor brains. Patient-derived
-mutant glioma tumorspheres overexpressed DLL3 and were potently sensitive to Rova-T in an antigen-dependent manner.
DLL3 is selectively and homogeneously expressed in
-mutant gliomas and can be targeted with Rova-T in patient-derived
-mutant glioma tumorspheres. Our findings are potentially immediately translatable and have implications for therapeutic strategies that exploit cell surface tumor-associated antigens.
Chimeric antigen receptor (CAR) T cells in solid tumors have so far yielded limited results, in terms of therapeutic effects, as compared to the dramatic results observed for hematological ...malignancies. Many factors involve both the tumor cells and the microenvironment. The lack of specific target antigens and severe, potentially fatal, toxicities caused by on-target off-tumor toxicities constitute major hurdles. Furthermore, the tumor microenvironment is usually characterized by chronic inflammation, the presence of immunosuppressive molecules, and immune cells that can reduce CAR T cell efficacy and facilitate antigen escape. Nonetheless, solid tumors are under investigation as possible targets despite their complexity, which represents a significant challenge. In preclinical mouse models, CAR T cells are able to efficiently recognize and kill several tumor xenografts. Overall, in the next few years, there will be intensive research into optimizing novel cell therapies to improve their effector functions and keep untoward effects in check. In this review, we provide an update on the state-of-the-art CAR T cell therapies in solid tumors, focusing on the preclinical studies and preliminary clinical findings aimed at developing optimal strategies to reduce toxicity and improve efficacy.
Introduction: Immunotherapy embodies any approach that manipulates the immune system for therapeutic benefit. In this regard, various clinical trials have employed direct vaccination with ...patient-specific dendritic cells or adoptive T cell therapy to target highly aggressive tumors. Both modalities have demonstrated great specificity, an advantage that is unmatched by other treatment strategies. However, their full potential has yet to be realized.
Areas covered: In this review, we provide an overview of chemokines in pathogen and anti-tumor immune responses and discuss further improving immunotherapies by arming particular chemokine axes.
Expert commentary: The chemokine macrophage inflammatory protein-1 alpha (MIP-1α, CCL3) has emerged as a potent activator of both innate and adaptive responses. Specifically, CCL3 plays a critical role in recruiting distinct immune phenotypes to intratumoral sites, is a pivotal player in regulating lymph node homing of dendritic cell subsets, and induces antigen-specific T cell responses. The recent breadth of literature outlines the various interactions of CCL3 with these cellular subsets, which have now served as a basis for immunotherapeutic translation.
Chimeric antigen receptor (CAR) transduced T cells represent a promising immune therapy that has been shown to successfully treat cancers in mice and humans. However, CARs targeting antigens ...expressed in both tumors and normal tissues have led to significant toxicity. Preclinical studies have been limited by the use of xenograft models that do not adequately recapitulate the immune system of a clinically relevant host. A constitutively activated mutant of the naturally occurring epidermal growth factor receptor (EGFRvIII) is antigenically identical in both human and mouse glioma, but is also completely absent from any normal tissues.
We developed a third-generation, EGFRvIII-specific murine CAR (mCAR), and performed tests to determine its efficacy in a fully immunocompetent mouse model of malignant glioma.
At elevated doses, infusion with EGFRvIII mCAR T cells led to cures in all mice with brain tumors. In addition, antitumor efficacy was found to be dependent on lymphodepletive host conditioning. Selective blockade with EGFRvIII soluble peptide significantly abrogated the activity of EGFRvIII mCAR T cells in vitro and in vivo, and may offer a novel strategy to enhance the safety profile for CAR-based therapy. Finally, mCAR-treated, cured mice were resistant to rechallenge with EGFRvIII(NEG) tumors, suggesting generation of host immunity against additional tumor antigens.
All together, these data support that third-generation, EGFRvIII-specific mCARs are effective against gliomas in the brain and highlight the importance of syngeneic, immunocompetent models in the preclinical evaluation of tumor immunotherapies.
Adoptive transfer of T cells expressing chimeric antigen receptors (CARs) is an effective immunotherapy for B-cell malignancies but has failed in some solid tumors clinically. Intracerebral tumors ...may pose challenges that are even more significant. In order to devise a treatment strategy for patients with glioblastoma (GBM), we evaluated CARs as a monotherapy in a murine model of GBM. CARs exhibited poor expansion and survival in circulation and failed to treat syngeneic and orthotopic gliomas. We hypothesized that CAR engraftment would benefit from host lymphodepletion prior to immunotherapy and that this might be achievable by using temozolomide (TMZ), which is standard treatment for these patients and has lymphopenia as its major side effect. We modelled standard of care temozolomide (TMZ
SD
) and dose-intensified TMZ (TMZ
DI
) in our murine model. Both regimens are clinically approved and provide similar efficacy. Only TMZ
DI
pretreatment prompted dramatic CAR proliferation and enhanced persistence in circulation compared to treatment with CARs alone or TMZ
SD
+ CARs. Bioluminescent imaging revealed that TMZ
DI
+ CARs induced complete regression of 21-day established brain tumors, which correlated with CAR abundance in circulation. Accordingly, TMZ
DI
+ CARs significantly prolonged survival and led to long-term survivors. These findings are highly consequential, as it suggests that GBM patients may require TMZ
DI
as first line chemotherapy prior to systemic CAR infusion to promote CAR engraftment and antitumor efficacy. On this basis, we have initiated a phase I trial in patients with newly diagnosed GBM incorporating TMZ
DI
as a preconditioning regimen prior to CAR immunotherapy (NCT02664363).
Median survival for glioblastoma (GBM) remains <15 months. Human cytomegalovirus (CMV) antigens have been identified in GBM but not normal brain, providing an unparalleled opportunity to subvert CMV ...antigens as tumor-specific immunotherapy targets. A recent trial in recurrent GBM patients demonstrated the potential clinical benefit of adoptive T-cell therapy (ATCT) of CMV phosphoprotein 65 (pp65)-specific T cells. However,
analyses from this study found no change in the capacity of CMV pp65-specific T cells to gain multiple effector functions or polyfunctionality, which has been associated with superior antitumor efficacy. Previous studies have shown that dendritic cells (DC) could further enhance tumor-specific CD8
T-cell polyfunctionality
when administered as a vaccine. Therefore, we hypothesized that vaccination with CMV pp65 RNA-loaded DCs would enhance the frequency of polyfunctional CMV pp65-specific CD8
T cells after ATCT. Here, we report prospective results of a pilot trial in which 22 patients with newly diagnosed GBM were initially enrolled, of which 17 patients were randomized to receive CMV pp65-specific T cells with CMV-DC vaccination (CMV-ATCT-DC) or saline (CMV-ATCT-saline). Patients who received CMV-ATCT-DC vaccination experienced a significant increase in the overall frequencies of IFNγ
, TNFα
, and CCL3
polyfunctional, CMV-specific CD8
T cells. These increases in polyfunctional CMV-specific CD8
T cells correlated (
= 0.7371,
= 0.0369) with overall survival, although we cannot conclude this was causally related. Our data implicate polyfunctional T-cell responses as a potential biomarker for effective antitumor immunotherapy and support a formal assessment of this combination approach in a larger randomized study.
A randomized pilot trial in patients with GBM implicates polyfunctional T-cell responses as a biomarker for effective antitumor immunotherapy.
.
Chimeric antigen receptor (CAR) T cells have shown promise against solid tumors, but their efficacy has been limited, due in part, to immunosuppression by CD4
FoxP3
regulatory T cells (Tregs). ...Although lymphodepletion is commonly used to deplete Tregs, these regimens are nonspecific, toxic, and provide only a narrow window before Tregs repopulate hosts. Importantly, CARs have also been shown to inadvertently potentiate Tregs by providing a source of IL2 for Treg consumption. We explored whether disruption of the IL2 axis would confer efficacy against solid tumors without the need for lymphodepletion.
We developed second- (CD28z) and third- (CD28-4-1BBz) generation CARs targeting EGFRvIII. To eliminate secretion of IL2, 2 amino acid substitutions were introduced in the PYAP Lck-binding motif of the CD28 domain (ΔCD28). We evaluated CARs against B16 melanomas expressing EGFRvIII.
CD28z CARs failed to engraft
. Although 4-1BB addition improved expansion, CD28-4-1BBz CARs required lymphodepletion to treat solid tumors. CARs deficient in Lck signaling, however, significantly retarded tumor growth without a need for lymphodepletion and this was dependent on inclusion of 4-1BB. To evaluate CAR vulnerability to Tregs, we lymphodepleted mice and transferred CARs alone or with purified Tregs. Cotransfer with Tregs abrogated the efficacy of CD28-4-1BBz CARs, whereas the efficacy of ΔCD28-4-1BBz CARs remained unperturbed.
In the absence of lymphodepletion, CARs targeting solid tumors are hindered by Treg immunosuppression and poor persistence. Here, CARs were modified to circumvent Treg suppression and to simultaneously improve
engraftment. Modified CARs treated solid tumors without a need for lymphodepletion.
•Obstacles for CED of CAR T cells are sedimentation, tube clogging, low viability.•LV Hydrogel is a biodegradable hyaluronic acid based biomaterial.•LV Hydrogel provides 20-fold increase in the ...delivery rate of CAR T cells.•Migration capacity and cytotoxicity of CAR T cells remain the same after infusion.•LV hydrogel has no toxic effect on rodent brain and fully disintegrated after 2 weeks.
Convection Enhanced Delivery (CED) infuses therapeutic agents directly into the intracranial area continuously under pressure. The convection improves the distribution of therapeutics such as those aimed at brain tumors. Although CED successfully delivers small therapeutic agents, this technique fails to effectively deliver cells largely due to cell sedimentation during delivery. To overcome this limitation, we have developed a low viscosity hydrogel (LVHydrogel), which is capable of retaining cells in suspension. In this study, we evaluated whether LVHydrogel can effectively act as a carrier for the CED of tumor-specific chimeric antigen receptor (CAR) T cells. CAR T cells were resuspended in saline or LVHydrogel carriers, loaded into syringes, and passed through the CED system for 5 h. CAR T cells submitted to CED were counted and the efficiency of delivery was determined. In addition to delivery, the ability of CAR T cells to migrate and induce cytotoxicity was evaluated. Our studies demonstrate that LVHydrogel is a superior carrier for CED in comparison to saline. The efficiency of cell delivery in saline carrier was only ∼3–5% of the total cells whereas delivery by the LVHydrogel carrier was much higher, reaching ∼45–75%. Migration and Cytotoxicity was similar in both carriers in non-infused samples but we found superior cytotoxicity in LVHydrogel group post-infusion. We demonstrate that LVHydrogel, a biodegradable biomaterial which does not cause acute toxicity on preclinical animal models, prevents cellular sedimentation during CED and presents itself as a superior carrier to the current carrier, saline, for the CED of CAR T cells.
Controlling length of stay (LOS) reduces rates of nosocomial infections and falls, facilitates earlier return to daily activities, and decreases strain on the healthcare system. Complications ...following supratentorial tumor resection present early in the postoperative period, thereby enhancing the prospect of safe, early discharge. Here, the authors describe their initial experience with the development and implementation of an Enhanced Recovery After Cranial Surgery (ERACS) pathway following resection of supratentorial tumors in select patients.
This was a nonrandomized, ambispective quality improvement study of patients undergoing elective craniotomy for supratentorial tumor resection at New York University Langone Health between November 17, 2020, and May 19, 2022. Eligible patients were prospectively enrolled in either the ERACS pathway or the standard pathway. These prospective cohorts were compared to a retrospective cohort of patients who met eligibility criteria for the pathway. Patients in the ERACS pathway cohort were targeted for discharge on postoperative day 2. The primary outcome metric was hospital LOS. Secondary outcome metrics included duration of intensive care unit (ICU) care and rates of 30-day emergency department visits, readmissions, and complications.
Over the study period, 188 of 317 patients (59.3%) who underwent supratentorial tumor resection met inclusion criteria for ERACS pathway enrollment. Sixty-three patients were enrolled in the ERACS pathway, and 125 patients completed the standard pathway. The historical cohort consisted of 332 patients who would have been eligible for ERACS enrollment. Patients in the ERACS pathway cohort had a median LOS of 1.93 days compared with 2.92 and 2.88 days for patients in the standard pathway and historical cohort, respectively (p < 0.001). There was a significant reduction in ICU utilization in ERACS pathway patients (16.0 ± 6.53 vs 29.5 ± 53.0 vs 21.8 ± 18.2 hours, p = 0.005). There were no differences in the rates of 30-day emergency department visits (12.7% vs 9.6% vs 10.9%, p = 0.809) and readmissions (4.8% vs 4.0% vs 7.8%, p = 0.279) between groups.
Patients in the ERACS pathway cohort experienced reduced LOS and ICU utilization, with similar rates of adverse outcomes compared to standard pathway patients. The authors' initial experience suggests that an accelerated recovery pathway can be safely implemented following supratentorial tumor resection in select patients.
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