Pan Zheng

PRESERVE-003 is a two-stage phase 3 trial evaluating gotistobart (BNT316/ONC-392), a novel pH-sensitive anti-cytotoxic T lymphocyte-associated protein 4 (CTLA-4) antibody that selectively depletes regulatory T cells within the tumor microenvironment, in patients with metastatic squamous non-small cell lung cancer (sqNSCLC) without actionable genomic alterations who progressed on programmed cell death protein/programmed death ligand 1 inhibitor/platinum-based chemotherapy—a population with a poor prognosis. Here we report on stage 1, which aimed to confirm the dose and assess the preliminary efficacy (primary outcome: overall survival; secondary outcomes: progression‑free survival, objective response rate and duration of response) and safety of gotistobart compared to docetaxel. Patients with sqNSCLC were randomized (1:1) to gotistobart (6 mg kg ⁻¹ with two 10 mg kg ⁻¹ loading doses every 3 weeks ( N = 45)) or docetaxel (75 mg m ^{− 2} every 3 weeks ( N = 42)). After a median follow-up of 14.5 months, median overall survival was not reached with gotistobart (95% confidence interval (CI) 9.3 to not evaluable) versus 10.0 months (95% CI 6.2 to 11.9 months) with docetaxel (hazard ratio 0.46, 95% CI 0.25 to 0.84, nominal two-sided P = 0.0102). Safety was manageable, with grade ≥3 treatment-related adverse events in 42% and 49% of patients receiving gotistobart and docetaxel, respectively. Stage 1 results suggest that gotistobart monotherapy can provide clinically meaningful benefit for patients with programmed cell death protein/programmed death ligand 1-resistant and chemotherapy-resistant metastatic sqNSCLC. ClinicalTrials.gov identifier: NCT05671510 .

Anti-CTLA-4 Abs (ACAs) are a breakthrough for cancer therapy, but their potential is limited by immunotherapy-related adverse events (irAE). We previously reported that ACAs with acidic pH-sensitive binding to CTLA-4 exhibit higher antitumor activity with fewer irAE. We now test a panel of variants of Ipilimumab (Ipi), the first ACA cancer therapeutic, for tumoricidal efficacy and irAE. Surprisingly, not all pH-sensitive Ipi variants exhibited an enhanced therapeutic index. Ipi13, which retained binding to CTLA-4 at pH 6.0 but dissociated at lower pH, showed no enhancement. By contrast, Ipi25, which dissociates from CTLA-4 at pH 6.0, the pH of the early endosome (EE), showed greater tumor regression and less severe irAE. Confocal microscopy showed that Ipi13 maintained colocalization with CTLA-4 at the late endosomes (LE) and lysosomes resulting in lysosomal degradation of CTLA-4. Conversely, Ipi25 did not colocalize with CTLA-4 in LE or lysosomes after endocytosis but allowed both proteins to transfer to recycling endosomes. EE dissociation was also characteristic of variants of Tremelimumab (Treme), another clinical ACA, that showed better efficacy and fewer side effects. Thus, our data reveal the significance of early intracellular dissociation from CTLA-4 to improve ACAs for safer and more effective cancer immunotherapy.

Patients who undergo human leukocyte antigen–matched unrelated donor (MUD) allogeneic hematopoietic stem cell transplantation (HSCT) with myeloablative conditioning for hematologic malignancies often develop acute graft-versus-host disease (GVHD) despite standard calcineurin inhibitor–based prophylaxis in combination with methotrexate. This trial evaluated a novel human CD24 fusion protein (CD24Fc/MK-7110) that selectively targets and mitigates inflammation due to damage-associated molecular patterns underlying acute GVHD while preserving protective immunity after myeloablative conditioning. This phase 2a, multicenter study evaluated the pharmacokinetics, safety, and efficacy of CD24Fc in combination with tacrolimus and methotrexate in preventing acute GVHD in adults undergoing MUD HSCT for hematologic malignancies. A double-blind, placebo-controlled, dose-escalation phase to identify a recommended dose was followed by an open-label expansion phase with matched controls to further evaluate the efficacy and safety of CD24Fc in preventing acute GVHD. A multidose regimen of CD24Fc produced sustained drug exposure with similar safety outcomes when compared with single-dose regimens. Grade 3 to 4 acute GVHD–free survival at day 180 was 96.2% (95% confidence interval [CI], 75.7-99.4) in the CD24Fc expansion cohort (CD24Fc multidose), compared with 73.6% (95% CI, 63.2-81.4) in matched controls (hazard ratio, 0.1 [95% CI, 0.0-0.6]; log-rank test, P = .03). No participants in the CD24Fc escalation or expansion phases experienced dose-limiting toxicities (DLTs). The multidose regimen of CD24Fc was well tolerated with no DLTs and was associated with high rates of severe acute GVHD–free survival after myeloablative MUD HSCT. This trial was registered at ClinicalTrials.gov as #NCT02663622.

Germline CTLA-4 deficiency causes severe autoimmune diseases characterized by dysregulation of Foxp3⁺ Tregs, hyper-activation of effector memory T cells, and variable forms autoimmune cytopenia including gradual loss of B cells. Cancer patients with severe immune-related adverse events (irAE) after receiving anti-CTLA-4/PD-1 combination immunotherapy also have markedly reduced peripheral B cells. The immunological basis for B cell loss remains unexplained. Here, we probe the decline of B cells in human CTLA-4 knock-in mice by using anti-human CTLA-4 antibody Ipilimumab conjugated to a drug payload emtansine (Anti-CTLA-4 ADC). The anti-CTLA-4 ADC-treated mice have T cell hyper-proliferation and their differentiation into effector cells which results in B cell depletion. B cell depletion is mediated by both CD4 and CD8 T cells and at least partially rescued by anti-TNF-alpha antibody. These data revealed an unexpected antagonism between T and B cells and the importance of regulatory T cells in preserving B cells.

Germline CTLA-4 deficiency causes severe autoimmune diseases characterized by dysregulation of Foxp3+ Tregs, hyper-activation of effector memory T cells, and variable forms autoimmune cytopenia including gradual loss of B cells. Cancer patients with severe immune-related adverse events (irAE) after receiving anti-CTLA-4/PD-1 combination immunotherapy also have markedly reduced peripheral B cells. The immunological basis for B cell loss remains unexplained. Here we probe the decline of B cells in human CTLA-4 knock-in mice by using anti-human CTLA-4 antibody Ipilimumab conjugated to a drug payload emtansine (Anti-CTLA-4 ADC). The anti-CTLA-4 ADC-treated mice have T cell hyper-proliferation and their differentiation into effector cells which results in B cell depletion. B cell depletion is mediated by both CD4 and CD8 T cells and at least partially rescued by anti-TNF-alpha antibody. These data revealed an unexpected antagonism between T and B cells and the importance of regulatory T cells in preserving B cells.

Major challenges such as nuclease degradation, rapid renal clearance, non-specific delivery, poor cellular uptake and inflammatory response have limited the clinical application of small RNA-mediated gene silencing. To overcome these challenges, we designed a novel targeting small RNA delivery platform comprising of three oligonucleotides: (1) a guide RNA sequence, (2) part of a passenger sequence linked to a DNA aptamer via a PEG linker, and (3) another passenger sequence conjugated to cholesterol, which assemble through complementary base pair annealing. Remarkably, in the presence of magnesium, this molecule self-assembled into a nanoparticle with a hydrophobic cholesterol core, hydrophilic RNA oligonucleotide shell and PEG-linked DNA aptamer flare. The nanoparticles conferred protection to the RNA oligonucleotides against nuclease degradation, which increased bioavailability, and reduced systemic inflammatory responses. The aptamer allowed targeted delivery of RNA therapeutics through cell-specific surface markers, and once inside the cell, the nanoparticles induced lysosomal leakage that released the RNA oligonucleotides into the cytosol to achieve gene silencing. We created a c-Kit-targeting miR-26a delivery particle that specifically accumulated in c-Kit⁺ breast cancer, significantly increased T cell recruitment, and inhibited tumor growth. Regression of large established tumors were achieved when the nanoparticle was used in combination with anti-CTLA-4 monoclonal antibody.

A subset of group 3 medulloblastoma frequently harbors amplification or overexpression of MYC lacking additional focal aberrations, yet it remains unclear whether MYC overexpression alone can induce tumorigenesis and which cells give rise to these tumors. Here, we showed that astrocyte progenitors in the early postnatal cerebellum were susceptible to transformation by MYC. The resulting tumors specifically resembled human group 3 medulloblastoma based on histology and gene-expression profiling. Gene-expression analysis of MYC-driven medulloblastoma cells revealed altered glucose metabolic pathways with marked overexpression of lactate dehydrogenase A (LDHA). LDHA abundance correlated positively with MYC expression and was associated with poor prognosis in human group 3 medulloblastoma. Inhibition of LDHA significantly reduced growth of both mouse and human MYC-driven tumors but had little effect on normal cerebellar cells or SHH-associated medulloblastoma. By generating a new mouse model, we demonstrated for the first time that astrocyte progenitors can be transformed by MYC and serve as the cells of origin for group 3 medulloblastoma. Moreover, we identified LDHA as a novel, specific therapeutic target for this devastating disease.Significance:Insights from a new model identified LDHA as a novel target for group 3 medulloblastoma, paving the way for the development of effective therapies against this disease.

Figure S1 shows MYC driven tumors generated from early postnatal cerebellar cells. Figure S2 shows IHC staining of tdt+ or tdt- MYC-driven tumors. Figure S3 shows gene expression of mouse MYC-driven tumors compared to that of human medulloblastomas. Figure S4 shows properties of Sox2+/Aldh1L1high, Sox2+/Aldh1L1low and Sox2+/Aldh1L1neg cells. Figure S5 shows properties of Sox2+/CD133+, Sox2+/CD133- or Sox2-/CD133+ cells. Figure S6 shows gene expression of SOX family members in tumors or normal cerebellar cells. Figure S7 shows that LDHA is a potential target for treating human MYC-amplified medulloblastoma.

Figure S1 shows MYC driven tumors generated from early postnatal cerebellar cells. Figure S2 shows IHC staining of tdt+ or tdt- MYC-driven tumors. Figure S3 shows gene expression of mouse MYC-driven tumors compared to that of human medulloblastomas. Figure S4 shows properties of Sox2+/Aldh1L1high, Sox2+/Aldh1L1low and Sox2+/Aldh1L1neg cells. Figure S5 shows properties of Sox2+/CD133+, Sox2+/CD133- or Sox2-/CD133+ cells. Figure S6 shows gene expression of SOX family members in tumors or normal cerebellar cells. Figure S7 shows that LDHA is a potential target for treating human MYC-amplified medulloblastoma.