Current Development Status of Cytokines for Cancer Immunotherapy

Tumor-derived extracellular vesicles: Hijacking T cell function through exhaustion

Extracellular vesicles (EVs) play a vital role in intercellular communication within the tumor microenvironment (TME). These vesicles, secreted by tumor cells, contain proteins, lipids, and nucleic acids that significantly influence immune responses, particularly impacting T-cell function. In cancer, T cell dysfunction and exhaustion-marked by reduced proliferation, diminished cytokine production, and impaired cytotoxic activity-are key barriers to effective immune responses. Tumor-derived extracellular vesicles (TEVs) contribute to this dysfunction by carrying immunosuppressive molecules, such as transforming growth factor-beta (TGF-β) and various microRNAs (miRNAs). These TEV-mediated mechanisms promote T cell exhaustion and foster a broader immunosuppressive environment, enabling tumor progression and immune evasion. Furthermore, TEVs have been implicated in resistance to cancer immunotherapies, including immune checkpoint inhibitors and T cell therapies. Understanding the molecular pathways and cargoes within TEVs that drive T cell dysfunction is crucial for developing novel therapeutic strategies aimed at reinvigorating exhausted T cells, enhancing anti-tumor immunity, and improving cancer treatment outcomes.

Phase I trial of phIL12 plasmid intratumoral gene electrotransfer in patients with basal cell carcinoma in head and neck region

INTRODUCTION

In the treatment of cancer, immunomodulatory approaches are developed to support the organism in fighting cancer or to enhance the immunomodulatory effects of local ablative techniques. To this end, we conducted an interventional, open-label, single-arm Phase I trial to evaluate the safety and tolerability of intratumoral phIL12 plasmid DNA gene electrotransfer as primary objectives.

METHODS

The study was dose-escalating with 3 consecutive cohorts of 3 patients per phIL12 dose level (0.5 mg/ml, 1 mg/ml or 2 mg/ml) according to a matched 3 + 3 design. Recruitment of patients was staggered. The waiting period was 30 days after treatment of the previous patient, based on the expected duration of acute and subacute toxicity.

RESULTS

The results of this phase I clinical trial in basal cell carcinoma demonstrated the feasibility and safety of the phIL12 plasmid by gene electrotransfer. We were able to demonstrate that phIL12 gene electrotransfer induced local IL-12 production, which was accompanied with IFN-γ expression. Triggering of the immune response was demonstrated by increased infiltration of immune cells and some antitumor effect. Based on these data, we would recommend the use of a concentration of 2 mg/ml of the plasmid in future trials.

CONCLUSION

The trial lays the foundation for future Phase II clinical trials in which phIL12 gene electrotransfer is used in combination with local tumor-ablative approaches, such as electrochemotherapy or radiotherapy.

Active Substances from the Micro-Immunotherapy Medicine 2LC1® Show In Vitro Anti-Cancer Properties in Colon, Prostate, and Breast Cancer Models and Immune-Enhancing Capabilities in Human Macrophages

Tumor-associated macrophages (TAMs) play a pivotal role in cancer regulation by influencing tumor growth, metastasis, and the immune microenvironment. By providing low doses and ultra-low doses (ULD) of immune regulators to the organism, micro-immunotherapy (MI) medicines (MIM) could be seen as valuable adjuvant drugs in the context of a wide range of pathological conditions, including cancers. Thus, these MIM could target TAMs, affecting their phenotype and activities. In this study, the anti-tumor and the immune-stimulatory effects of four capsules out of the ten composing the Labo'life's MIM 2LC1® (2LC1-1, 2LC1-6, 2LC1-7, and 2LC1-8), as well as the specific nucleic acid (SNA®) sequence SNA-MYC present at ULD in this medicine have been evaluated in vitro, in several cancer models, and in human monocyte-derived macrophages. Our results showed that the tested MI formulations increased the tumor cell death of spheroids from HCT-116 colon cancer cells, while reducing the spheroid volume. Moreover, the treatments impaired the clonogenic capabilities of two cancer cell lines from epithelial origin, the LNCaP prostate cancer and the MCF-7 breast cancer cells. Interestingly, ULD of the SNA-MYC shared similar anti-cancer capabilities in those models, and it led to a significant reduction in the expression of C-MYC when evaluated in a model of human M2 macrophages. In the same model, the MI formulations also increased the expression of CD86 and HLA-DR, two markers of M1 anti-tumor macrophages. In addition, the tested items modulated the secretion of a panel of chemokines related to macrophage activity and immune cell recruitment. Finally, our results showed that 2LC1-8 increased the phagocytosis capabilities of human monocyte-derived macrophages, thus possibly contributing to sustaining the immune functions of M1, which are crucial in the context of cancer. Even if more research is needed to uncover their exact mechanism of action, these results suggest that the tested capsules of 2LC1 as well as ULD of SNA-MYC display both anti-tumor and immune-enhancing effects.

[Which Immunotherapies are Standard Today? And What Side Effects Should be Expected?]

In comparison to earlier treatment standards (including chemotherapy, radiation therapy, and surgery), immunotherapy has significantly improved patients' survival and quality of life. Immunotherapy is ultimately a broad term that encompasses a variety of therapeutics. Immunotherapeutic approaches have firmly established themselves as a new pillar of cancer care, ranging from neoadjuvant and adjuvant strategies to the metastatic phase in various entities. In this review article, we highlight which immunotherapies are currently standard in oncological care, with a strong focus on immune checkpoint inhibitors (ICIs), their limitations, and the commonly occurring side effects.

First-in-human phase I study to evaluate safety, tolerability, pharmacokinetics, pharmacodynamics, immunogenicity, and antitumor activity of PF-07209960 in patients with advanced or metastatic solid tumors

BACKGROUND

PF-07209960 is an antibody-cytokine fusion molecule that consists of a single potency-reduced interleukin-15 (IL-15) mutein and a bivalent high-affinity anti-programmed cell death protein 1 (PD-1) full-length IgG. This phase I study (NCT04628780) evaluated the safety, tolerability, pharmacokinetics (PK), pharmacodynamics, and potential clinical benefits of PF-07209960 in patients with selected locally advanced or metastatic solid tumors for whom no standard therapy was available.

MATERIALS AND METHODS

Escalating doses (1-30 mg) of PF-07209960 were administered subcutaneously once every 2 weeks in 28-day cycles. The primary endpoints included dose-limiting toxicities (DLTs), adverse events (AEs), and laboratory abnormalities. The secondary endpoints included PK, anti-drug antibodies (ADA) and neutralizing antibodies (NAb) against PF-07209960, and tumor response assessed using RECIST version 1.1.

RESULTS

Thirty-seven patients received treatment with PF-07209960 (1-, 3-, and 10-mg groups, n = 4 each; 15 mg, n = 3; 20 mg, n = 16; 30 mg, n = 6). The median age was 59.0 years (range 31-88 years). Six (22.2%) patients had DLTs. The most frequently reported treatment-related AEs (TRAEs) (≥50%) were general disorders and administration site condition [21 (56.8%)] and skin and subcutaneous tissue disorders [20 (54.1%)]. The most frequently reported grade ≥3 TRAE was anemia [5 (13.5%)]. Two patients with microsatellite-stable colorectal cancer had confirmed partial response, one each from the PF-07209960 20-mg and 30-mg cohorts, with a duration of response of 9.5 and 3 months, respectively. The rate of ADA was 93.9% (31/33), of which 63.6% (21/33) was treatment induced and 30.3% (10/33) was treatment boosted.

CONCLUSION

PF-07209960 was generally manageable, with potential antitumor activity in some patients.

Efficacy of Anti-Cancer Immune Responses Elicited Using Tumor-Targeted IL-2 Cytokine and Its Derivatives in Combined Preclinical Therapies

Effective cancer therapies must address the tumor microenvironment (TME), a complex network of tumor cells and stromal components, including endothelial, immune, and mesenchymal cells. Durable outcomes require targeting both tumor cells and the TME while minimizing systemic toxicity. Interleukin-2 (IL-2)-based therapies have shown efficacy in cancers such as metastatic melanoma and renal cell carcinoma but are limited by severe side effects. Innovative IL-2-based immunotherapeutic approaches include immunotoxins, such as antibody-drug conjugates, immunocytokines, and antibody-cytokine fusion proteins that enhance tumor-specific delivery. These strategies activate cytotoxic CD8+ T lymphocytes and natural killer (NK) cells, eliciting a potent Th1-mediated anti-tumor response. Modified IL-2 variants with reduced Treg cell activity further improve specificity and reduce immunosuppression. Additionally, IL-2 conjugates with peptides or anti-angiogenic agents offer improved therapeutic profiles. Combining IL-2-based therapies with immune checkpoint inhibitors (ICIs), anti-angiogenic agents, or radiotherapy has demonstrated synergistic potential. Preclinical and clinical studies highlight reduced toxicity and enhanced anti-tumor efficacy, overcoming TME-driven immune suppression. These approaches mitigate the limitations of high-dose soluble IL-2 therapy, promoting immune activation and minimizing adverse effects. This review critically explores advances in IL-2-based therapies, focusing on immunotoxins, immunocytokines, and IL-2 derivatives. Emphasis is placed on their role in combination strategies, showcasing their potential to target the TME and improve clinical outcomes effectively. Also, the use of IL-2 immunocytokines in "in situ" vaccination to relieve the immunosuppression of the TME is discussed.

Augmentation of Solid Tumor Immunotherapy With IL-12

Immunotherapy describes a class of therapies in which the immune system is manipulated for therapeutic benefit. These treatments include immune checkpoint inhibitors, adoptive cell therapy, and vaccines. For many hematological malignancies, immunotherapy has emerged as an essential treatment component. However, this success has yet to be replicated for solid tumors, which develop advanced physical and molecular mechanisms for suppressing and evading immune destruction. Nevertheless, cytokine immunotherapy presents a potential remedy to these barriers by delivering a proinflammatory immune signal to the tumor and thereby transforming it from immunologically "cold" to "hot." Interleukin-12 (IL-12), one of the most potent proinflammatory cytokines, was initially investigated for this purpose. However, initial murine and human studies in which IL-12 was administered systemically resulted in dangerous immunotoxicity associated with off-target immune activation. As a result, recent studies have employed advanced cell and molecular engineering approaches to reduce IL-12 toxicity while increasing or maintaining its efficacy such that its effective doses can be tolerated in humans. This review highlights such developments and identifies promising future directions.

Non-clinical evaluation of pmIL12 gene therapy for approval of the phase I clinical study

Immunotherapeutic drugs are promising medicines for cancer treatment. A potential candidate for immunotherapy is interleukin-12 (IL-12), a cytokine well known for its ability to mediate antitumor activity. We developed a plasmid encoding human IL-12 devoid of an antibiotic resistance gene (phIL12). For the approval of phase I clinical trials in basal cell carcinoma (BCC), the regulatory agency requires non-clinical in vivo testing of the pharmacodynamic, pharmacokinetic and toxicological properties of the plasmid. As human IL-12 is not biologically active in mice, a mouse ortholog of the plasmid phIL12 (pmIL12) was evaluated. The evaluation demonstrated the antitumor effectiveness of the protein accompanied by immune cell infiltration. The plasmid was distributed throughout the body, and the amount of plasmid diminished over time in all organs except the skin around the tumor. The therapy did not cause any detectable systemic toxicity. The results of the non-clinical evaluation demonstrated the safety and efficacy of the pmIL12/phIL12 GET, and on the basis of these results, approval was obtained for the initiation of a phase I clinical study in BCC.

Dichotomous Effects of Glypican-4 on Cancer Progression and Its Crosstalk with Oncogenes

Glypicans are linked to various aspects of neoplastic behavior, and their therapeutic value has been proposed in different cancers. Here, we have systematically assessed the impact of GPC4 on cancer progression through functional genomics and transcriptomic analyses across a broad range of cancers. Survival analysis using TCGA cancer patient data reveals divergent effects of GPC4 expression across various cancer types, revealing elevated GPC4 expression levels to be associated with both poor and favorable prognoses in a cancer-dependent manner. Detailed investigation of the role of GPC4 in glioblastoma and non-small cell lung adenocarcinoma by genetic perturbation studies displays opposing effects on these cancers, where the knockout of GPC4 with CRISPR/Cas9 attenuated proliferation of glioblastoma and augmented proliferation of lung adenocarcinoma cells and the overexpression of GPC4 exhibited a significant and opposite effect. Further, the overexpression of GPC4 in GPC4-knocked-down glioblastoma cells restored the proliferation, indicating its mitogenic effect in this cancer type. Additionally, a survival analysis of TCGA patient data substantiated these findings, revealing an association between elevated levels of GPC4 and a poor prognosis in glioblastoma, while indicating a favorable outcome in lung carcinoma patients. Finally, through transcriptomic analysis, we attempted to assign mechanisms of action to GPC4, as we find it implicated in cell cycle control and survival core pathways. The analysis revealed upregulation of oncogenes, including FGF5, TGF-β superfamily members, and ITGA-5 in glioblastoma, which were downregulated in lung adenocarcinoma patients. Our findings illuminate the pleiotropic effect of GPC4 in cancer, underscoring its potential as a putative prognostic biomarker and indicating its therapeutic implications in a cancer type dependent manner.