Neratinib as Extended Adjuvant Treatment of HER2-Positive/HR-Positive Early Breast Cancer Patients in Germany, Austria, and Switzerland: Interim Results of the Prospective, Observational ELEANOR Study.

Introduction: Prognosis of patients diagnosed with HER2+ early breast cancer (eBC) has substantially improved, but distant recurrences impacting quality of life and survival still occur. One treatment option for extended adjuvant treatment of patients with HER2+/HR+ eBC is neratinib, available in Europe for patients who completed adjuvant trastuzumab-based therapy within 1 year. The ELEANOR study is investigating the real-world use of neratinib in Germany, Austria, and Switzerland. Results from an interim analysis of the first 200 patients observed for ≥3 months are reported. Methods: The primary objective of this prospective, multicenter, observational study is to assess patient adherence to neratinib (defined as the percentage of patients taking neratinib on ≥75% prescribed days). Secondary objectives are patient characteristics and treatment outcomes. Results: At cut-off (May 2, 2022), a total of 202 patients had been observed for ≥3 months, with neratinib treatment documented for 187 patients (median age: 53.0 years; 67.9% at increased risk of disease recurrence). In total, 151 (80.7%) patients had received prior neoadjuvant treatment; of these, 82 (54.3%) patients achieved a pathologically complete response. Neratinib was initiated at a median 3.6 months after trastuzumab-based treatment, with 36.4% starting at a dose <240 mg/day. Treatment is ongoing for 46.0% of patients, with median treatment duration of 11.2 (interquartile range 0.9-12.0) months. Diarrhea was the most common adverse event (78.6% any grade, 20.3% grade ≥3); pharmacologic prophylaxis was used in 85.6% of patients. Conclusions: The pattern of anti-HER2 pretreatment observed reflected the current treatment for HER2+/HR+ eBC in Germany, Austria, and Switzerland. These interim results suggest that neratinib as an extended adjuvant is a feasible option after various anti-HER2 pretreatments and that its tolerability can be managed and improved with proactive diarrhea management.

Neratinib as extended adjuvant therapy in patients with copositive early breast cancer: German health technology assessment-driven analyses from the ExteNET study.

BACKGROUND: Neratinib is approved in the European Union for extended adjuvant treatment of human epidermal growth factor receptor 2-positive/hormone receptor-positive (copositive) early breast cancer ≤1 year of completion of prior trastuzumab-based therapy. Here, we report analyses of the hormone receptor-positive subgroup (N = 1631) from the ExteNET trial performed for the German health technology assessment (HTA). RESULTS: With 2 years of median follow-up, HTA analyses revealed a significant advantage in disease-free survival (DFS) for neratinib vs. placebo (absolute/relative risk reduction: 4.1/48.2%; hazard ratio [HR] [95% confidence interval {CI}]: 0.45 [0.29; 0.69]; p = 0.0002), consistent with distant DFS (absolute/relative risk reduction: 3.1/46.3%; HR [95% CI]: 0.52 [0.32; 0.84]; p = 0.0082). The 5-year follow-up confirmed this outcome.Quality of life analyses did not show clinically relevant differences over all time points. Only at month 1, the Functional Assessment of Cancer Therapy - General total score revealed a statistically relevant difference to the disadvantage of neratinib classified as clinically relevant. The tolerability profile of neratinib was dominated by gastrointestinal events, mainly diarrhoea (all grades: 94.4%; grade III: 39.4%; no systematic antidiarrhoeal prophylaxis), nausea (all grades/grade III: 43.9/1.6%), vomiting (26.6/3.2%), abdominal pain (23.8/1.9%), fatigue (28.1/1.9%) and rash (14.3/0.4%). No cumulative or irreversible toxicities were observed. As shown in the CONTROL study and instituted via a risk management plan, diarrhoea management can reduce frequency, cumulative duration and severity of diarrhoea. CONCLUSION: Extended adjuvant neratinib provides a clinically relevant benefit with further incremental reduction of relapse risk in the curative setting. Accordingly, the German HTA authority has granted an added benefit for this new treatment option.

A Phase Ib Study of Alpelisib or Buparlisib Combined with Tamoxifen Plus Goserelin in Premenopausal Women with HR-Positive HER2-Negative Advanced Breast Cancer.

PURPOSE: This study reports the MTD, recommended phase 2 dose (RP2D), and preliminary efficacy of alpelisib or buparlisib used in combination with tamoxifen plus goserelin in premenopausal patients with hormone receptor-positive (HR+), HER2-negative (HER2-) advanced breast cancer (ABC). PATIENTS AND METHODS: This study enrolled premenopausal women with HR+, HER2- ABC. Patients received tamoxifen (20 mg once daily) and goserelin acetate (3.6 mg every 28 days) with either alpelisib (350 mg once daily; n = 16) or buparlisib (100 mg once daily; n = 13) in 28-day cycles until MTD was observed. RESULTS: The criteria for MTD were not met for both alpelisib and buparlisib. The RP2D of alpelisib and buparlisib in combination with tamoxifen and goserelin were 350 mg and 100 mg, respectively. Both combinations met protocol-specified criteria for tolerability. The most common grade 3/4 treatment-emergent adverse events (TEAE) were hypokalemia (12.5%), hyperglycemia (6.3%), and rash (6.3%) for alpelisib and alanine aminotransferase increase (30.8%), aspartate aminotransferase increase (23.1%), and anxiety (15.4%) for buparlisib. TEAEs led to treatment discontinuation in 18.8% and 53.8% of alpelisib- and buparlisib-treated patients, respectively. Progression-free survival was 25.2 months in the alpelisib group and 20.6 months in the buparlisib group. CONCLUSIONS: The RP2Ds of alpelisib and buparlisib were 350 mg and 100 mg, respectively. No unexpected safety findings were reported. Although an early-phase study, data suggest that alpelisib plus endocrine therapy may be a potentially efficacious treatment that warrants further evaluation for premenopausal patients with HR+, HER2- ABC.See related commentary by Clark et al., p. 371.

Identification of a new subset of myeloid suppressor cells in peripheral blood of melanoma patients with modulation by a granulocyte-macrophage colony-stimulation factor-based antitumor vaccine.

PURPOSE: Phenotypic and functional features of myeloid suppressor cells (MSC), which are known to serve as critical regulators of antitumor T-cell responses in tumor-bearing mice, are still poorly defined in human cancers. Here, we analyzed myeloid subsets with suppressive activity present in peripheral blood of metastatic melanoma patients and evaluated their modulation by a granulocyte-macrophage colony-stimulating factor (GM-CSF)--based antitumor vaccine. PATIENTS AND METHODS: Stage IV metastatic melanoma patients (n = 16) vaccinated with autologous tumor-derived heat shock protein peptide complex gp96 (HSPPC-96) and low-dose GM-CSF provided pre- and post-treatment whole blood specimens. Peripheral-blood mononuclear cells (PBMCs) were analyzed by flow cytometry, separated into cellular subsets, and used for in vitro proliferation assays. PBMCs from stage-matched metastatic melanoma patients (n = 12) treated with non-GM-CSF-based vaccines (ie, HSPPC-96 alone or interferon alfa/melanoma-derived peptides) or sex- and age-matched healthy donors (n = 16) were also analyzed for comparison. RESULTS: The lack of or low HLA-DR expression was found to identify a CD14+ cell subset highly suppressive of lymphocyte functions. CD14+HLA-DR-/lo cells were significantly expanded in all metastatic melanoma patients, whereas they were undetectable in healthy donors. Suppressive activity was mediated by transforming growth factor beta (TGF-beta), whereas no involvement of the arginase and inducible nitric oxide synthase pathways could be detected. CD14+HLA-DR-/lo cells, as well as spontaneous ex vivo release and plasma levels of TGF-beta, were augmented after administration of the HSPPC-96/GM-CSF vaccine. No enhancement of the CD14+-mediated suppressive activity was found in patients receiving non-GM-CSF-based vaccines. CONCLUSION: CD14+HLA-DR-/lo cells exerting TGF-beta-mediated immune suppression represent a new subset of MSC potentially expandable by the administration of GM-CSF-based vaccines in metastatic melanoma patients.

Tumor-released microvesicles as vehicles of immunosuppression.

Tumor-released microvesicles, or exosomes, which are abundant in the body fluids of patients with cancer, are likely to be involved in tumor progression. We recently showed that microvesicles released by human melanoma and colorectal carcinoma cells can promote the differentiation of monocytes to myeloid-derived suppressor cells which support tumoral growth and immune escape. These findings underscore an important role for these extracellular organelles in remodeling tumor-stromal interactions to promote malignancy.

Human tumor-released microvesicles promote the differentiation of myeloid cells with transforming growth factor-beta-mediated suppressive activity on T lymphocytes.

Human tumors constitutively release endosome-derived microvesicles, transporting a broad array of biologically active molecules with potential modulatory effects on different immune cells. Here, we report the first evidence that tumor-released microvesicles alter myeloid cell function by impairing monocyte differentiation into dendritic cells and promoting the generation of a myeloid immunosuppressive cell subset. CD14+ monocytes isolated from healthy donors and differentiated with interleukin (IL)-4 and granulocyte macrophage colony-stimulating factor in the presence of tumor-derived microvesicles turned into HLA-DR(-/low) cells, retaining CD14 expression and failing to up-regulate costimulatory molecules, such as CD80 and CD86. These phenotypic changes were paralleled by a significant release of different cytokines, including IL-6, tumor necrosis factor-alpha, and transforming growth factor-beta (TGF-beta), and a dose-dependent suppressive activity on activated T-cell-proliferation and cytolytic functions, which could be reversed by anti-TGF-beta-neutralizing antibodies. Microvesicles isolated from plasma of advanced melanoma patients, but not from healthy donors, mediated comparable effects on CD14+ monocytes, skewing their differentiation toward CD14+HLA-DR-/low cells with TGF-beta-mediated suppressive activity on T-cell-functions. Interestingly, a subset of TGF-beta-secreting CD14+HLA-DR- cells mediating suppressive activity on T lymphocytes was found to be significantly expanded in peripheral blood of melanoma patients compared with healthy donors. These data suggest the development in cancer patients of an immunosuppressive circuit by which tumors promote the generation of suppressive myeloid cells through the release of circulating microvesicles and without the need for cell-to-cell contact. Therapeutic interventions on the crucial steps of this pathway may contribute to restore tumor/immune system interactions favoring T-cell-mediated control of tumor growth in cancer patients.

Vaccination: role in metastatic melanoma.

Based on the poor impact on overall survival obtained by systemic chemotherapy in metastatic melanoma and the identification of many melanoma antigens recognized by T cells, in the last decade many efforts have been devoted to the development of active specific immunotherapy as a promising systemic treatment for this neoplastic disease. A number of Phase I-II clinical trials have been performed with different vaccination approaches that included whole tumor cells, antigen peptides, antigen-pulsed dendritic cells, recombinant viruses, plasmids or naked DNA, and heat-shock proteins. Despite some promising immunological and clinical results obtained in these studies, melanoma-specific vaccines have altogether failed to prove their efficacy in the few large Phase III randomized clinical trials performed. Nonetheless, the possibility of activating the human immune system to recognize and destroy tumor cells remains a challenging investigative field, considering that the new knowledge of the intricate cellular and molecular mechanisms that regulate the immune function and tumor-host interactions may allow the development of new clinically relevant melanoma vaccination strategies.

Human colorectal cancer cells induce T-cell death through release of proapoptotic microvesicles: role in immune escape.

BACKGROUND & AIMS: Normal and neoplastic cells release microvesicles, whose effects on the immune system still need to be elucidated. Because human colorectal cancer cells are hypothesized to escape immune recognition by expressing proapoptotic molecules, we investigated whether microvesicles bearing Fas ligand and tumor necrosis factor-related apoptosis-inducing ligand and inducing apoptosis of activated T cells are secreted by colorectal cancer cells both in vitro and in affected patients. METHODS: Fas ligand and tumor necrosis factor-related apoptosis-inducing ligand expression were analyzed in colorectal cancer cells and purified microvesicles by flow cytometry, Western blotting, and immunoelectron microscopy. Microvesicle tumor origin was assessed through simultaneous detection of lysosomal (CD63) and adenocarcinoma (carcinoembryonic antigen) markers. Proapoptotic activity of microvesicles was evaluated by annexin V/propidium iodide staining and caspase activation in T cells, including CD8+ T lymphocytes from colorectal cancer patients. RESULTS: Colorectal cancer cells showed a granular pattern of tumor necrosis factor-related apoptosis-inducing ligand and Fas ligand expression, suggesting a secretory behavior. These proapoptotic molecules were detected on isolated microvesicles, together with class I HLA, CD63, and carcinoembryonic antigen. Microvesicles induced Fas ligand-mediated and tumor necrosis factor-related apoptosis-inducing ligand-mediated apoptosis of activated CD8+ T cells generated from colorectal cancer patients. Microvesicles with comparable phenotypes and functions were found in plasma from patients with advanced disease, whereas vesicular structures expressing Fas ligand and tumor necrosis factor-related apoptosis-inducing ligand were also detected in colorectal cancer specimens. CONCLUSIONS: These data show that colorectal cancer induces T-cell apoptosis through the release of Fas ligand-bearing and tumor necrosis factor-related apoptosis-inducing ligand-bearing microvesicles both in vitro and in vivo. This mechanism of immune escape has potential implications as a prognostic factor and could be targeted for the development of new antitumor therapies in colorectal cancer patients.

Escape strategies and reasons for failure in the interaction between tumour cells and the immune system: how can we tilt the balance towards immune-mediated cancer control?

The last decade has witnessed an exponential increase in the attempts to demonstrate that adaptive immunity can effectively detect cancer cells and impair their growth in vivo in cancer patients. However, clinical trials of immunotherapy with a broad array of immunisation strategies have depicted a rather disappointing scenario, suggesting that successful control of tumour growth by immunotherapeutic treatments may not be an easy task to achieve. The attention of tumour immunologists has thus been switched to the potential reasons of failure, and extensive efforts are being made in defining the cellular and molecular pathways interfering with the capacity of the immune system to develop powerful immunological reactions against tumour cells. Although many of these pathways have been well characterised in murine models, little and controversial information about their role in determining neoplastic progression in cancer patients is available. This discrepancy at the moment represents one of the major limitations in understanding the obstacles to the in vivo development of protective T cell-mediated immune responses against tumours, and how pharmacological or biological interventions aimed at bypassing tumour escape mechanisms would indeed result in a clinical benefit. The study of the reasons for the failure of the immune system to control tumour growth, which have to be ascribed to highly interconnected phenomena occurring at both tumour and immune levels, could in the near future provide adequate tools to fight cancer by finely tuning the host environment through biological therapies.

Role of cross-talk between IFN-alpha-induced monocyte-derived dendritic cells and NK cells in priming CD8+ T cell responses against human tumor antigens.

In the present study we evaluated the role of IFN-alpha in the generation of dendritic cells (IFN-DCs) with priming activity on CD8(+) T lymphocytes directed against human tumor Ags. A 3-day treatment of monocytes, obtained as adherent PBMCs from HLA-A*0201(+) healthy donors, with IFN-alpha and GM-CSF led to the differentiation of DCs displaying a semimature phenotype, but promptly inducing CD8(+) T cell responses after one in vitro sensitization with peptides derived from melanoma (gp100(209-217) and MART-1/Melan-A(27-35)) and adenocarcinoma (CEA(605-613)) Ags. However, these features were lost when IFN-DCs were generated from immunosorted CD14(+) monocytes. The ability of adherent PBMCs to differentiate into IFN-DCs expressing higher levels of costimulatory molecules and exerting efficient T cell priming capacity was associated with the presence of contaminating NK cells, which underwent phenotypic and functional activation upon IFN-alpha treatment. NK cell boost appeared to be mediated by both direct and indirect (i.e., mediated by IFN-DCs) mechanisms. Experiments performed to prove the role of contaminating NK cells in DC differentiation showed that IFN-DCs generated in the absence of NK were phenotypically less mature and could not efficiently prime antitumor CD8(+) lymphocytes. Reciprocally, IFN-DCs raised from immunosorted CD14(+) monocytes regained their T cell priming activity when NK cells were added to the culture before IFN-alpha and GM-CSF treatment. Together, our data suggest that the ability of IFN-DCs to efficiently prime anti-tumor CD8(+) T lymphocytes relied mostly on the positive cross-talk occurring between DCs and NK cells upon stimulation with IFN-alpha.