Facing challenges with hope: universal immune cells for hematologic malignancies

Viral oncogenesis in cancer: from mechanisms to therapeutics

The year 2024 marks the 60th anniversary of the discovery of the Epstein-Barr virus (EBV), the first virus confirmed to cause human cancer. Viral infections significantly contribute to the global cancer burden, with seven known Group 1 oncogenic viruses, including hepatitis B virus (HBV), human papillomavirus (HPV), EBV, Kaposi sarcoma-associated herpesvirus (KSHV), hepatitis C virus (HCV), human T-cell leukemia virus type 1 (HTLV-1), and human immunodeficiency virus (HIV). These oncogenic viruses induce cellular transformation and cancer development by altering various biological processes within host cells, particularly under immunosuppression or co-carcinogenic exposures. These viruses are primarily associated with hepatocellular carcinoma, gastric cancer, cervical cancer, nasopharyngeal carcinoma, Kaposi sarcoma, lymphoma, and adult T-cell leukemia/lymphoma. Understanding the mechanisms of viral oncogenesis is crucial for identifying and characterizing the early biological processes of virus-related cancers, providing new targets and strategies for treatment or prevention. This review first outlines the global epidemiology of virus-related tumors, milestone events in research, and the process by which oncogenic viruses infect target cells. It then focuses on the molecular mechanisms by which these viruses induce tumors directly or indirectly, including the regulation of oncogenes or tumor suppressor genes, induction of genomic instability, disruption of regular life cycle of cells, immune suppression, chronic inflammation, and inducing angiogenesis. Finally, current therapeutic strategies for virus-related tumors and recent advances in preclinical and clinical research are discussed.

Safety and efficacy of CD33-targeted CAR-NK cell therapy for relapsed/refractory AML: preclinical evaluation and phase I trial

BACKGROUND

Due to the lack of effective treatment options, the prognosis of patients with relapsed/refractory acute myeloid leukemia (R/R AML) remains poor. Although chimeric antigen receptor (CAR)-T-cell therapy has shown promising effects in acute lymphoblastic leukemia (ALL) and lymphoma, its application in R/R AML is limited by "off-target" effects, which lead to severe bone marrow suppression and limit its clinical application. CAR-natural killer (NK) cells not only exhibit antitumor effects but also demonstrate increased safety and universality. We have developed a new CAR construct that targets CD33 and modified NK cells, specifically eliminating AML cells while reducing severe side effects on stem cells.

METHODS

The CD33-targeting domain was selected by CAR-T cells, and this optimized CAR construct was subsequently transduced into umbilical cord-derived NK cells via a retroviral vector. Preclinical efficacy and safety studies were conducted both in vitro and in vivo. Ten eligible patients with R/R AML aged 18-65 years who received one or more infusions of anti-CD33 CAR-NK cells following the preconditioning regimen were enrolled. We assessed the response rates and treatment-related side effects post-infusion, while also documenting the long-term efficacy of the therapy.

RESULTS

The CD33 sequence was selected on the basis of its antitumor efficacy and safety in CAR-T-cell studies conducted both in vitro and in vivo. CD33 CAR-NK cells demonstrated efficacy comparable to that of CD33 CAR-T cells but showed limited toxicity to hematopoietic stem cells (HSCs). Ten patients, with a median of five prior lines of treatment, completed the efficacy evaluation (range, 3-8). No grade 3-4 adverse events were observed, except bone marrow suppression, which was relieved within one month. No cases of immune effector cell-associated neurotoxicity syndrome (ICANS) or graft-versus-host disease (GVHD) were reported following CAR-NK cell infusion. Only one patient experienced grade 2 cytokine release syndrome (CRS) and presented with persistent fever. By day 28, six of ten patients had achieved minimal residual disease (MRD)-negative complete remission.

CONCLUSIONS

Our preclinical and clinical data demonstrated the primary efficacy and safety of CD33 CAR-NK cells for patients with R/R AML. Expanded samples and longer follow-up periods are needed to provide further efficacy data.

TRIAL REGISTRATION

NCT05008575 ( https://clinicaltrials.gov/study/NCT05008575 ).

Long-term survival with donor CD19 CAR-T cell treatment for relapsed patients after allogeneic hematopietic stem cell transplantation

Chimeric Antigen Receptor T (CAR-T) cell therapy has significantly advanced in treating B-cell acute lymphoblastic leukemia (B-ALL) and has shown efficacy in managing relapsed B-ALL after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Donor-derived CAR-T cell offer both high efficacy and rapid response. Although promising results exist, current research lacks definitive evidence of long-term survival benefits for patients treated with donor-derived CAR-T therapy. We report the long-term survival of 32 patients with post-transplant relapsed B-ALL treated with donor-derived CD19 CAR-T cell, achieving either complete Remission (CR) or CR with incomplete peripheral blood recovery (CRi). The median follow-up was 42 months, with 2-year overall survival (OS) and event-free survival (EFS) rates of 56.25% and 50.0%, respectively. The 5-year OS and EFS rates were 53.13% and 46.88%, with no new long-term adverse events observed. These findings demonstrate good long-term safety, supporting donor-derived CAR-T cell as a recommended treatment option for relapsed B-ALL patients post-transplantation. Trial registration: https://www.chictr.org.cn/showproj.html?proj=14315 . Registration number: ChiCTR-OOC-16008447.