Adjuvant endocrine therapy uptake, toxicity, quality of life, and prediction of early discontinuation.

BACKGROUND: Many patients receiving adjuvant endocrine therapy (ET) for breast cancer experience side effects and reduced quality of life (QoL) and discontinue ET. We sought to describe these issues and develop a prediction model of early discontinuation of ET. METHODS: Among patients with hormone receptor-positive and HER2-negative stage I-III breast cancer of the Cancer Toxicities cohort (NCT01993498) who were prescribed adjuvant ET between 2012 and 2017, upon stratification by menopausal status, we evaluated adjuvant ET patterns including treatment change and patient-reported discontinuation and ET-associated toxicities and impact on QoL. Independent variables included clinical and demographic features, toxicities, and patient-reported outcomes. A machine-learning model to predict time to early discontinuation was trained and evaluated on a held-out validation set. RESULTS: Patient-reported discontinuation rate of the first prescribed ET at 4 years was 30% and 35% in 4122 postmenopausal and 2087 premenopausal patients, respectively. Switching to a new ET was associated with higher symptom burden, poorer QoL, and higher discontinuation rate. Early discontinuation rate of adjuvant ET before treatment completion was 13% in postmenopausal and 15% in premenopausal patients. The early discontinuation model obtained a C index of 0.62 in the held-out validation set. Many aspects of QoL, most importantly fatigue and insomnia (European Organization for Research and Treatment of Cancer QoL questionnaire 30), were associated with early discontinuation. CONCLUSION: Tolerability and adherence to ET remains a challenge for patients who switch to a second ET. An early discontinuation model using patient-reported outcomes identifies patients likely to discontinue their adjuvant ET. Improved management of toxicities and novel more tolerable adjuvant ETs are needed for maintaining patients on treatment.

Impact of radiation therapy on fatigue at 1 year in breast cancer survivors in the prospective multicentre CANcer TOxicity cohort.

BACKGROUND: Fatigue is a common and disabling symptom after breast cancer (BC) treatment, significantly impacting patients' quality of life. We aimed to assess the impact of radiation therapy (RT) modalities on fatigue one year after treatment among patients with early-stage BC. METHODS: We used CANTO-RT, a subcohort of CANcer TOxicity (CANTO; NCT01993498), a multicentric nationwide prospective cohort of stages I-III BC treated from 2012 to 2017. Our primary outcome was severe global fatigue 1 year after RT completion (European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-C30 score ≥40/100). The secondary outcomes included severe physical, emotional and cognitive fatigue (European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-FA12). RT-related variables were used as independent variables. Multivariable logistic regression models assessed associations between RT-related variables and fatigue. RESULTS: The final analytic cohort included 3295 patients. The prevalence of severe global fatigue 1 year after treatment was 33.3%. Internal mammary chain RT (adjusted odds ratio [OR] 1.48 [95% confidence interval [CI] 1.03-2.13; p = 0.0355]) and normofractionated RT (adjusted OR 1.88 [95% CI 1.06-3.31; p = 0.0298]) were associated with increased odds of severe global fatigue. In addition, there was a significant association between normofractionated RT (adjusted OR 1.849 [95% CI 1.04-3.3; p = 0.0354]) and an increased likelihood of severe physical fatigue. CONCLUSION: We found a significant association between internal mammary chain RT (versus No), normofractionated RT (versus hypofractionated RT) and increased likelihood of persistent severe global fatigue. Our data add to the current understanding of treatment-related factors affecting fatigue after BC and could lead to personalised interventions to improve the prevention and management of this disabling symptom.

Genomics to select treatment for patients with metastatic breast cancer.

Cancer progression is driven in part by genomic alterations1. The genomic characterization of cancers has shown interpatient heterogeneity regarding driver alterations2, leading to the concept that generation of genomic profiling in patients with cancer could allow the selection of effective therapies3,4. Although DNA sequencing has been implemented in practice, it remains unclear how to use its results. A total of 1,462 patients with HER2-non-overexpressing metastatic breast cancer were enroled to receive genomic profiling in the SAFIR02-BREAST trial. Two hundred and thirty-eight of these patients were randomized in two trials (nos. NCT02299999 and NCT03386162) comparing the efficacy of maintenance treatment5 with a targeted therapy matched to genomic alteration. Targeted therapies matched to genomics improves progression-free survival when genomic alterations are classified as level I/II according to the ESMO Scale for Clinical Actionability of Molecular Targets (ESCAT)6 (adjusted hazards ratio (HR): 0.41, 90% confidence interval (CI): 0.27-0.61, P < 0.001), but not when alterations are unselected using ESCAT (adjusted HR: 0.77, 95% CI: 0.56-1.06, P = 0.109). No improvement in progression-free survival was observed in the targeted therapies arm (unadjusted HR: 1.15, 95% CI: 0.76-1.75) for patients presenting with ESCAT alteration beyond level I/II. Patients with germline BRCA1/2 mutations (n = 49) derived high benefit from olaparib (gBRCA1: HR = 0.36, 90% CI: 0.14-0.89; gBRCA2: HR = 0.37, 90% CI: 0.17-0.78). This trial provides evidence that the treatment decision led by genomics should be driven by a framework of target actionability in patients with metastatic breast cancer.

Contraceptive Use in Premenopausal Women With Early Breast Cancer.

Importance: As life span has increased among patients with cancer, survivorship has become an important component of breast cancer care. Among survivorship concerns, adequate contraceptive counseling is needed for premenopausal patients who are not seeking to become pregnant. Objective: To examine contraceptive use and chosen methods and to assess factors associated with contraceptive use over time in patients with early breast cancer. Design, Setting, and Participants: The Cancer Toxicity (CANTO) study was a multicenter nationwide prospective cohort study that enrolled women diagnosed with stage I to stage III breast cancer in France between March 2012 and December 2017. This analysis included 2900 premenopausal women who were 50 years of age or younger at diagnosis. Data were analyzed from July 2020 to July 2022. Exposures: Contraceptive use and method at diagnosis, shortly after the end of primary treatment (year 1), and during follow-up (year 2). Main Outcomes and Measures: Contraceptive use and methods were longitudinally evaluated at diagnosis, year 1, and year 2 after breast cancer diagnosis. Multivariable logistic regression models were used to assess the associations of clinical, socioeconomic, treatment, adverse effect, and patient-reported outcome variables with contraceptive use after diagnosis. Results: A total of 2900 patients (mean [SD] age, 43.1 [5.6] years) were included in the analysis; 2050 of 2894 women (70.8%) received chemotherapy, and 2305 of 2880 women (80.0%) received endocrine therapy. After diagnosis, 1182 of 2625 patients (45.0%) at year 1 and 1553 of 2363 patients (65.7%) at year 2 reported consulting with a gynecologist in the previous year. At diagnosis, 1487 of 2744 patients (54.2%) reported contraceptive use, with most patients (921 of 1470 women [62.7%]) using hormonal methods. The use of contraception significantly decreased after diagnosis (911 of 2342 patients [38.9%] at year 1 and 808 of 1961 patients [41.2%] at year 2; P < .001 for trend), when most patients (848 of 900 women [94.2%] at year 1 and 767 of 805 women [95.3%] at year 2) reported use of nonhormonal methods; these methods were primarily reversible mechanical approaches (copper intrauterine devices: 656 of 848 patients [77.4%] at year 1 and 577 of 767 patients [75.2%] at year 2; male condoms: 115 of 848 patients [13.6%] at year 1 and 110 of 767 patients [14.3%] at year 2). In the multivariable model, factors significantly associated with contraceptive use at year 1 included using contraception at diagnosis (adjusted odds ratio [aOR], 4.02; 95% CI, 3.15-5.14), being younger (aOR, 1.09; 95% CI, 1.07-1.13 per decreasing year), having better sexual function (aOR, 1.13; 95% CI, 1.07-1.19 per 10-point increment), having children (aOR, 4.21; 95% CI, 1.80-9.86), reporting the presence of leukorrhea (aOR, 1.32; 95% CI, 1.03-1.70), receiving tamoxifen treatment alone (aOR, 1.39; 95% CI, 1.01-1.92), and consulting with a gynecologist in the previous year (aOR, 1.29; 95% CI, 1.02-1.63). Similar factors were associated with contraceptive use at year 2, with the addition of partnered status (aOR, 1.61; 95% CI, 1.07-2.44). Conclusions and Relevance: Findings from this study support the importance of raising awareness and improving targeted contraceptive counseling for premenopausal women with early breast cancer.

Coffee and tea consumption, patient-reported, and clinical outcomes in a longitudinal study of patients with breast cancer.

BACKGROUND: Higher consumption of coffee and tea has been associated with improved health outcomes in the general population and improved breast cancer (BC) prognosis. This study investigated patterns of coffee and tea consumption and association with patient-reported outcomes (PROs) and clinical outcomes among survivors of BC. METHODS: The authors included survivors of stage I-III BC enrolled in the CANTO cohort (NCT01993498) that provided post-treatment assessment of coffee and tea consumption from years 1 to 4 after diagnosis. Group-based trajectory modeling clustered patients according to daily consumption of coffee and tea. Multivariable mixed models and Cox models examined associations between consumption, PROs and clinical outcomes. RESULTS: Among 3788 patients, the authors identified four stable patterns of consumption: "Low" (25.8%), "Moderate" (37.6%), "High" (25.3%), and "Very high" (11.3%), corresponding to <1, 2, 3, and ≥ 4 cups of coffee and/or tea per day. Patients in the "Very high" group (vs. "Low"), were more likely to be younger, smokers, with higher monthly income and education. PROs and survival outcomes were similar across the four groups. CONCLUSIONS: Over one in three survivors of BC reported high or very high consumption of coffee and/or tea. The authors found no association between higher consumption of coffee and/or tea, worse PROs and clinical outcomes.

Comprehensive Genome Profiling in Patients With Metastatic Non-Small Cell Lung Cancer: The Precision Medicine Phase II Randomized SAFIR02-Lung/IFCT 1301 Trial.

PURPOSE: Targeted therapies (TT) and immune checkpoint blockers (ICB) have revolutionized the approach to non-small cell lung cancer (NSCLC) treatment in the era of precision medicine. Their impact as switch maintenance therapy based on molecular characterization is unknown. PATIENTS AND METHODS: SAFIR02-Lung/IFCT 1301 was an open-label, randomized, phase II trial, involving 33 centers in France. We investigated eight TT (substudy-1) and one ICB (substudy-2), compared with standard-of-care as a maintenance strategy in patients with advanced EGFR, ALK wild-type (wt) NSCLC without progression after first-line chemotherapy, based on high-throughput genome analysis. The primary outcome was progression-free survival (PFS). RESULTS: Among the 175 patients randomized in substudy-1, 116 received TT (selumetinib, vistusertib, capivasertib, AZD4547, AZD8931, vandetanib, olaparib, savolitinib) and 59 standard-of-care. Median PFS was 2.7 months [95% confidence interval (CI), 1.6-2.9] with TT versus 2.7 months (1.6-4.1) with standard-of-care (HR, 0.97; 95% CI, 0.7-1.36; P = 0.87). There were no significant differences in PFS within any molecular subgroup. In substudy-2, 183 patients were randomized, 121 received durvalumab and 62 standard-of-care. Median PFS was 3.0 months (2.3-4.4) with durvalumab versus 3.0 months (2.0-5.1) with standard-of-care (HR, 0.86; 95% CI, 0.62-1.20; P = 0.38). Preplanned subgroup analysis showed an enhanced benefit with durvalumab in patients with PD-L1 tumor proportion score (TPS) ≥1%, (n = 29; HR, 0.29; 95% CI, 0.11-0.75) as compared with PD-L1 <1% (n = 31; HR, 0.71; 95% CI, 0.31-1.60; Pinteraction = 0.036). CONCLUSIONS: Molecular profiling can feasibly be implemented to guide treatment choice for the maintenance strategy in EGFR/ALK wt NSCLC; in this study it did not lead to substantial treatment benefits beyond durvalumab for PD-L1 ≥ 1 patients.

Molecular profiling of non-small-cell lung cancer patients with or without brain metastases included in the randomized SAFIR02-LUNG trial and association with intracranial outcome.

INTRODUCTION: Lung cancer remains the most frequent cause of brain metastases (BMs) and is responsible for high morbidity and mortality. Intracranial response to systemic treatments is inconsistent due to several mechanisms: genomic heterogeneity, blood-tumor barrier, and the brain-specific microenvironment. We conducted a study using data from the SAFIR02-LUNG trial. The primary objective was to compare the molecular profiles of non-small-cell lung cancer (NSCLC) with or without BMs. The secondary objective was to explore central nervous system (CNS) outcomes with various maintenance treatment regimens. METHODS: In total, 365 patients harboring interpretable molecular data were included in this analysis. Clinical and biological data were collected. Genomic analyses were based on array-comparative genomic hybridization and next-generation sequencing (NGS) following the trial recommendations. RESULTS: Baseline genomic analyses of copy number variations identified a 24-gene signature specific to lung cancer BM occurrence, all previously known to take part in oncogenesis. NGS analysis identified a higher proportion of KRAS mutations in the BM-positive group (44.3% versus 32.3%), especially G12C mutations (63% versus 47%). Protein interaction analyses highlighted several functional interactions centered on EGFR. Furthermore, the risk of CNS progression was decreased with standard pemetrexed maintenance therapy. The highest rate of CNS progression was observed with durvalumab, probably because of the specific intracranial immune microenvironment. CONCLUSION: This work identified a 24-gene signature specific to lung cancer with BM. Further studies are needed to precisely determine the functional implications of these genes to identify new therapeutic targets for the treatment of lung cancer with BM.

CANTO-RT: Skin toxicities evaluation of a multicentre large prospective cohort of irradiated patients for early-stage breast cancer.

Skin damage is the most common and most important toxicity during and after radiation therapy (RT). Its assessment and understanding of the factors influencing its occurrence, is a major issue in the management of patients irradiated for an early breast cancer. CANTO is a prospective clinical cohort study of 10 150 patients with stage I-III BC treated from 2012 to 2017 in 26 cancer centres. In our study, we used CANTO-RT, a subcohort of CANTO, including 3480 patients who received RT. We are focus on specific skin toxicities: erythema, fibrosis, telangiectasia and cutaneous pigmentation. The prevalence of toxicities of interest varied over time, so at baseline for early toxicity Month (M) 0-3-6, 41.1% of patients had erythema while 24.8% of patients had fibrosis. At M12 and M36, the prevalence of erythema decreased, respectively, while fibrosis remains stable. The prevalence of telangiectasia increases from 1% to 7.1% from M0-3-6 to M36. After adjustments, we showed an association between the occurrence of skin erythema and obesity; the type of surgery; the presence of axillary dissection; the use of taxane-based CT and the 3D vs IMRT irradiation technique. Regarding fibrosis, an association is found, at M0-3-6, with age at diagnosis, obesity, tobacco and the use of boost. Only obesity and the type of surgery received by the patient remained statistically significant at M12 and M36. In our study we identified several risk factors for acute and late skin reactions. The use of a boost was mainly related to the occurrence of fibrosis while the use of IMRT-type technique decreased the occurrence of skin erythema.

Genomic Alterations in PIK3CA-Mutated Breast Cancer Result in mTORC1 Activation and Limit the Sensitivity to PI3Kα Inhibitors.

PI3Kα inhibitors have shown clinical activity in PIK3CA-mutated estrogen receptor-positive (ER+) patients with breast cancer. Using whole genome CRISPR/Cas9 sgRNA knockout screens, we identified and validated several negative regulators of mTORC1 whose loss confers resistance to PI3Kα inhibition. Among the top candidates were TSC1, TSC2, TBC1D7, AKT1S1, STK11, MARK2, PDE7A, DEPDC5, NPRL2, NPRL3, C12orf66, SZT2, and ITFG2. Loss of these genes invariably results in sustained mTOR signaling under pharmacologic inhibition of the PI3K-AKT pathway. Moreover, resistance could be prevented or overcome by mTOR inhibition, confirming the causative role of sustained mTOR activity in limiting the sensitivity to PI3Kα inhibition. Cumulatively, genomic alterations affecting these genes are identified in about 15% of PIK3CA-mutated breast tumors and appear to be mutually exclusive. This study improves our understanding of the role of mTOR signaling restoration in leading to resistance to PI3Kα inhibition and proposes therapeutic strategies to prevent or revert this resistance. SIGNIFICANCE: These findings show that genetic lesions of multiple negative regulators of mTORC1 could limit the efficacy of PI3Kα inhibitors in breast cancer, which may guide patient selection strategies for future clinical trials.

Durvalumab compared to maintenance chemotherapy in metastatic breast cancer: the randomized phase II SAFIR02-BREAST IMMUNO trial.

The impact of single-agent antibodies against programmed death-ligand 1 (PD-L1) as maintenance therapy is unknown in patients with metastatic breast cancer. The SAFIR02-BREAST IMMUNO substudy included patients with human epidermal growth factor receptor type 2 (Her2)-negative metastatic breast cancer whose disease did not progress after six to eight cycles of chemotherapy. Patients (n = 199) were randomized to either durvalumab (10 mg kg-1 every 2 weeks) or maintenance chemotherapy. In the overall population, durvalumab did not improve progression-free survival (adjusted hazard ratio (HR): 1.40, 95% confidence interval (CI): 1.00-1.96; P = 0.047) or overall survival (OS; adjusted HR: 0.84, 95% CI: 0.54-1.29; P = 0.423). In an exploratory subgroup analysis, durvalumab improved OS in patients with triple-negative breast cancer (TNBC; n = 82; HR: 0.54, 95% CI: 0.30-0.97, P = 0.0377). Exploratory analysis showed that the HR of death was 0.37 (95% CI: 0.12-1.13) for patients with PD-L1+ TNBC (n = 32) and 0.49 (95% CI: 0.18-1.34) for those with PD-L1- TNBC (n = 29). In patients with TNBC, exploratory analyses showed that the HR for durvalumab efficacy (OS) was 0.18 (95% CI: 0.05-0.71; log-rank test, P = 0.0059) in patients with CD274 gain/amplification (n = 23) and 1.12 (95% CI: 0.42-2.99; log-rank test, P = 0.8139) in patients with CD274 normal/loss (n = 32). Tumor infiltration by lymphocytes (CD8, FoxP3 and CD103 expressions) and homologous recombination deficiency did not predict sensitivity to durvalumab in exploratory analyses. This latter finding should be interpreted with caution since only one patient presented a germline BRCA mutation. The present study provides a rationale to evaluate single-agent durvalumab in maintenance therapy in patients with TNBC. Exploratory analyses identified CD274 amplification as a potential biomarker of sensitivity. Maintenance chemotherapy was more effective than durvalumab in patients with hormone receptor-positive and Her2-negative disease.

Author Correction: Genomic characterization of metastatic breast cancers.

An Amendment to this paper has been published and can be accessed via a link at the top of the paper.

Genomic characterization of metastatic breast cancers.

Metastasis is the main cause of death for patients with breast cancer. Many studies have characterized the genomic landscape of breast cancer during its early stages. However, there is evidence that genomic alterations are acquired during the evolution of cancers from their early to late stages, and that the genomic landscape of early cancers is not representative of that of lethal cancers1-7. Here we investigated the landscape of somatic alterations in 617 metastatic breast cancers. Nine driver genes (TP53, ESR1, GATA3, KMT2C, NCOR1, AKT1, NF1, RIC8A and RB1) were more frequently mutated in metastatic breast cancers that expressed hormone receptors (oestrogen and/or progesterone receptors; HR+) but did not have high levels of HER2 (HER2-; n = 381), when compared to early breast cancers from The Cancer Genome Atlas. In addition, 18 amplicons were more frequently observed in HR+/HER2- metastatic breast cancers. These cancers showed an increase in mutational signatures S2, S3, S10, S13 and S17. Among the gene alterations that were enriched in HR+/HER2- metastatic breast cancers, mutations in TP53, RB1 and NF1, together with S10, S13 and S17, were associated with poor outcome. Metastatic triple-negative breast cancers showed an increase in the frequency of somatic biallelic loss-of-function mutations in genes related to homologous recombination DNA repair, compared to early triple-negative breast cancers (7% versus 2%). Finally, metastatic breast cancers showed an increase in mutational burden and clonal diversity compared to early breast cancers. Thus, the genomic landscape of metastatic breast cancer is enriched in clinically relevant genomic alterations and is more complex than that of early breast cancer. The identification of genomic alterations associated with poor outcome will allow earlier and better selection of patients who require the use of treatments that are still in clinical trials. The genetic complexity observed in advanced breast cancer suggests that such treatments should be introduced as early as possible in the disease course.

Modeling the specific CD4+ T cell response against a tumor neoantigen.

The antitumor activity of CD4(+) T cells is increasingly acknowledged in both humans and mice. The involved mechanisms have been mostly studied using transplanted tumor mouse systems. In these models, many tumor cells die at the time of implantation leading to the release of Ag in an inflammatory context contrasting with the slow and nondestructive growth of early-stage human tumors. In this study, we show that the presentation of a MHC class II-restricted model Ag (male, DBY) released by dying tumor cells may last more than 4 wk. The duration of Ag presentation varies according to the way the cells are killed before implantation. To avoid this artifactual early priming of the host precluding the study of the interactions between the immune system and tumors at the steady state, we generated a cell line expressing the DBY Ag in an inducible manner. Ag expression can be efficiently induced in vivo several days after tumor implantation. We show that the Ag reaches the lymph node and activates naive CD4(+) T cells to proliferate and recirculate. We did not observe de novo induction of tumor-specific regulatory T cells. However, we observed Th1/Th17 effector cells in the tumor draining lymph node and tumors. Thus, when a neoantigen appears in established tumors, the immune system is not ignorant and naive CD4(+) T cells are not tolerized. This opens up the possibility of therapeutic vaccines improving the immune response toward tumor-specific neoantigens.

Combined glyco- and protein-Fc engineering simultaneously enhance cytotoxicity and half-life of a therapeutic antibody.

While glyco-engineered monoclonal antibodies (mAbs) with improved antibody-dependent cell-mediated cytotoxicity (ADCC) are reaching the market, extensive efforts have also been made to improve their pharmacokinetic properties to generate biologically superior molecules. Most therapeutic mAbs are human or humanized IgG molecules whose half-life is dependent on the neonatal Fc receptor FcRn. FcRn reduces IgG catabolism by binding to the Fc domain of endocytosed IgG in acidic lysosomal compartments, allowing them to be recycled into the blood. Fc-engineered mAbs with increased FcRn affinity resulted in longer in vivo half-life in animal models, but also in healthy humans. These Fc-engineered mAbs were obtained by alanine scanning, directed mutagenesis or in silico approach of the FcRn binding site. In our approach, we applied a random mutagenesis technology (MutaGen™) to generate mutations evenly distributed over the whole Fc sequence of human IgG1. IgG variants with improved FcRn-binding were then isolated from these Fc-libraries using a pH-dependent phage display selection process. Two successive rounds of mutagenesis and selection were performed to identify several mutations that dramatically improve FcRn binding. Notably, many of these mutations were unpredictable by rational design as they were located distantly from the FcRn binding site, validating our random molecular approach. When produced on the EMABling(®) platform allowing effector function increase, our IgG variants retained both higher ADCC and higher FcRn binding. Moreover, these IgG variants exhibited longer half-life in human FcRn transgenic mice. These results clearly demonstrate that glyco-engineering to improve cytotoxicity and protein-engineering to increase half-life can be combined to further optimize therapeutic mAbs.

Preclinical study of Ublituximab, a Glycoengineered anti-human CD20 antibody, in murine models of primary cerebral and intraocular B-cell lymphomas.

PURPOSE: Primary cerebral lymphoma (PCL) and primary intraocular lymphoma (PIOL) belong to the systemic diffuse large B-cell lymphoma family and are characterized by the presence of CD20(+) lymphoma B cells in the brain or the eye. These highly aggressive malignancies have a poor prognosis and no specific therapy. The presence of effector immune cells in the damaged brain and vitreous suggests that treatment with anti-human CD20 (hCD20) monoclonal antibodies might be effective. We developed murine models of PCL and PIOL to assess the intracerebral and intraocular antitumor effect of ublituximab, a promising glycoengineered anti-hCD20 mAb with a high affinity for FcγRIIIa (CD16) receptors. METHODS: The murine lymphoma B-cell line A20.IIA-GFP-hCD20 (H-2(d)) was injected into the right cerebral striatum or the vitreous of immunocompetent adult BALB/c mice (H-2(d)). Four to 7 days later, ublituximab was injected intracerebrally or intravitreously into the tumor site. Rituximab was the reference compound. Survival was monitored for injected mice; histopathological and flow cytometric analyses were performed to study tumor growth and T-cell infiltration. RESULTS: Single doses of ublituximab, injected intracerebrally or intravitreously, had a marked antitumor effect, more pronounced than that obtained with the same dose of rituximab in these conditions. The reduction in tumor cells was correlated with an increased proportion of CD8(+) T cells. This efficacy was observed only against lymphoma B cells expressing hCD20. CONCLUSIONS: These in vivo results confirm the potential of the glycoengineered anti-hCD20 mAb ublituximab as an innovative therapeutic approach to treat primary central nervous system lymphoma and other B-cell lymphomas.

Long peptide vaccination can lead to lethality through CD4+ T cell-mediated cytokine storm.

The optimization of anticancer therapeutic vaccines can lead to better efficacy but also to stronger adverse effects. In a mouse model of antitumor vaccination using a long peptide (LP), which included MHC class I- and II-restricted male (H-Y) epitopes, we observed unexpected mortality. Mice with an increased frequency of anti-H-Y CD4 T cells were primed with LP+CpG and boosted 10 d later. Within hours of boost, they displayed shock-like signs with high mortality. Serum cytokine levels were high. TNF-alpha secreted by the CD4 T cells was identified as the key effector molecule. Priming with a short peptide (SP), which included the MHC class II-restricted epitope, was a more efficient primer than LP, but did not lead to mortality when used as boost. The high mortality induced by LP compared with SP was probably related to its specific ability to be presented by B cells. Finally, targeting the LP sequence to dendritic cells allowed tumor protection without side effects. Our data: 1) confirm that the immune system can be very dangerous; 2) caution against the use of systemic activation of high-frequency Ag-specific T cells as induced by high doses of LP; and 3) underline the benefit of targeting Ag to dendritic cells.

The dendritic cell-like functions of IFN-producing killer dendritic cells reside in the CD11b+ subset and are licensed by tumor cells.

IFN producing killer dendritic cells (IKDC) were originally defined as CD11c(int) B220(+)NK1.1(+) (or CD49b(+)) cells that exert a potent tumoricidal activity in animals lacking B, T, and conventional natural killer effectors. MHC class II expression on tumor infiltrating IKDC prompted us to investigate their putative antigen presenting function. Here, we show that tumor cells license IKDC to acquire the properties of antigen presenting cells, i.e., expression of MHC class II and costimulatory CD86 molecules. We show that the CD11b(+) subset of IKDC are able to prime naïve CD4(+) T cells and cross-prime naïve CD8(+) T lymphocytes. Licensing of IKDC by tumor cells was mandatory for the full differentiation of T cells into polarized effectors. IKDC could engulf and process soluble Ova protein in a CD206-dependent manner. Finally, we show that CD11b(+)IKDC is selectively endowed with CTLA4Ig-inhibitable antigen presenting capacities and that targeting this subset with the detoxified adenylate cyclase toxin of Bordetella pertussis fused to antigen resulted in efficient cross-presentation of antigen by IKDC to specific TCR transgenic CD8(+)T cells in vivo. Collectively, our data indicate that upon exposure to tumor cells, IKDC subserve DC-like functions.

Antigen-specific T-T interactions regulate CD4 T-cell expansion.

The regulation of CD4 T-cell numbers during an immune response should take account of the amount of antigen (Ag), the initial frequency of Ag-specific T cells, the mix of naive versus experienced cells, and (ideally) the diversity of the repertoire. Here we describe a novel mechanism of T-cell regulation that potentially deals with all of these parameters. We found that CD4 T cells establish a negative feedback loop by capturing their cognate major histocompatibility class (MHC)/peptide complexes from Ag-presenting cells and presenting them to Ag-experienced CD4 T cells, thereby inhibiting their recruitment into the response while allowing recruitment of naive T cells. The inhibition is Ag specific, begins at day 2 (long before Ag disappearance), and cannot be overcome by providing new Ag-loaded dendritic cells. In this way, CD4 T-cell proliferation is regulated in a functional relationship to the amount of Ag, while allowing naive T cells to generate repertoire variety.

Intratumor CD4 T-cell accumulation requires stronger priming than for expansion and lymphokine secretion.

T cells need to migrate to and accumulate inside tumors before mediating rejection of the tumor. The number of specific T cells inside tumors may depend on the efficiency of priming in the draining lymph node (DLN), intratumor deletion, suppressive phenomena, or both. We used monoclonal anti-male antigen CD4 (Marilyn) T cells and tumor cell lines expressing or not the corresponding antigen (Dby) to analyze CD4 T-cell accumulation in tumors. Priming by MHC II(+) or MHC II(-) male splenocytes or Dby(+) tumor cells induced similar Marilyn T-cell expansion in the DLN and recirculation in other lymph nodes and capacity to produce IFN-gamma. However, intratumor accumulation was different for each priming condition. In mice with Dby(-) tumors, MHC II(+) male splenocyte priming induced greater, although not statistically significant, Marilyn T-cell accumulation in the tumors than MHC II(-) male splenocyte priming. In mice with Dby(+) tumors, priming in the tumor DLN induced less Marilyn T-cell intratumor accumulation than priming by MHC II(+) male splenocytes. We saw comparable differences for Marilyn T-cell accumulation in gut lamina propria, suggesting that priming affects effector T-cell accumulation in inflamed tissues. Mature dendritic cells were loaded with graded doses of Dby peptide to control for antigen-presenting cell characteristics during priming. We observed similar proliferation, with higher concentrations inducing higher intratumor accumulation. Thus, intratumor accumulation requires stronger stimulation than for proliferation or the capacity to secrete lymphokines. In this system, priming intensity alone can explain the number of intratumor T cells without having to call for intratumor deletion or suppression phenomena.