Completion Rate and Positive Results Reporting Among Immunotherapy Trials in Breast Cancer, 2004-2023.

Importance: Clinical trials are the path to test and introduce new therapies in the clinic. Trials that are unable to produce results represent inefficiency in the system and may also undermine patient confidence in the new drug development process. Objectives: To survey the immunotherapy clinical trial landscape of breast cancer between January 2004 and April 2023 and examine what fraction of trials with primary completion date up to November 30, 2022, failed to report outcome, assessing the proportion of trials that yielded positive results and describing trial features associated with these 2 outcomes. Design, Setting, and Participants: This cross-sectional study included breast cancer immunotherapy trials identified in ClinicalTrials.gov. Trial details and results were retrieved in December 2023. Google Scholar, PubMed, and LARVOL CLIN websites were also searched for reports. Main Outcomes and Measures: Trial outcome reported as abstract or manuscript. Reported trials were categorized as positive (ie, met its end point) or negative. Association between reporting and trial features were tested using Fisher exact test. Results: A total of 331 immuno-oncology trials were initiated in breast cancer by April 2023; 242 trials were phase II, 47 were phase I, and 42 phase III. By setting, 212 studies (64.0%) were conducted in metastatic, 94 (28.4%) in neoadjuvant, and 25 (7.6%) in adjuvant settings. Among phase II and III trials, 168 (59.2%) were nonrandomized. One hundred twenty trials had primary completion dates up to November 30, 2022, of which 30 (25.0%; enrolling a combined 2428 patients) failed to report their outcomes; 7 phase I trials (31.8%), 21 phase II trials (23.6%), and 2 phase III trials (22.2%) were unreported. Single-center studies were significantly more likely to be unreported than multicenter studies (19 of 54 [35.2%] vs 9 of 60 [15.0%]; P = .02). Of the 90 reported trials, 47 (52.2%) and 43 (47.8%) were positive and negative, respectively. Seventeen of 19 (89.5%) of the reported randomized trials (accruing a total of 4189 patients) were negative. Conclusions and Relevance: In this cross-sectional study of immunotherapy breast cancer trials, the large number of trials yielded modest clinical impact. Single-center trials commonly failed to report their outcomes and many phase II studies have not translated into corresponding successful phase III trials.

Management of Trastuzumab Deruxtecan-related nausea and vomiting in real-world practice.

Background: Nausea and vomiting are common side effects of Trastuzumab Deruxtecan (T-DXd), but guidelines for optimal management were not initially available. This retrospective single-center study aimed at evaluating the efficacy of two antiemetic regimens in patients receiving T-DXd. Methods: Data from metastatic breast cancer patients receiving T-DXd were collected. Two groups were defined: patients treated with 5-HT3 receptor antagonists (RA) ± dexamethasone (5-HT3-group) and patients treated with a fixed oral combination of netupitant (NK1RA) and palonosetron ± dexamethasone (NK1 group). Physicians preferentially offered the NK1 regimen to patients at higher risk of nausea and vomiting based on internal recommendations. Only nausea and vomiting during cycles 1 and 2 were considered. Comparisons of nausea and vomiting by the antiemetic prophylaxis group were assessed using chi-square. Results: A total of 53 patients were included in the analysis. At cycle 1, 72% and 28% of patients received the 5-HT3 and NK1 prophylaxis, respectively. Overall, 58% reported nausea, with no differences between groups (58% vs. 60%; p = 0.832), but with a trend for lower grade in the NK1 group (33.3% G1; 26.7% G2) compared to the 5-HT3 group (23.7% G1; 31.6% G2; 2.6% G3). Vomiting was reported by 21% and 0% of patients in the 5-HT3 and the NK1 group, respectively (p = 0.054). Among the 15 patients in the 5-HT3 group with nausea at cycle 1 who escalated to NK1 at cycle 2, nausea decreased from 100% to 53% (p = 0.022) and vomiting decreased from 47% to 13% (p = 0.046). Conclusions: The NK1 regimen improved vomiting control at cycle 1 and, when introduced at cycle 2, significantly improved both nausea and vomiting. The biased NK1 selection for higher-risk patients may have dampened the differences between groups at cycle 1. These findings support enhanced control of T-DXd-related nausea and vomiting with NK1RA.

Breast cancers with high proliferation and low ER-related signalling have poor prognosis and unique molecular features with implications for therapy.

BACKGROUND: Luminal breast cancers with high proliferation (MKShi) and low ER-related signalling (ERSlo) have a poor prognosis. We investigated treatment responses and molecular features of MKShi/ERSlo tumours to inform potential therapies. METHODS: Gene expression data from patients who received neoadjuvant chemotherapy (NAC) without (MDACC, N = 199) or with pembrolizumab (I-SPY2, N = 40), or endocrine therapy (NET) without (POETIC, N = 172) or with palbociclib (NeoPalAna, N = 32) were analyzed to assess treatment response by MKS/ERS-subgroups. TCGA was used to assess the mutational landscape and biomarkers associated with palbociclib-resistance (Cyclin-E, RBsig, IRPR) and immunotherapy-response (TMB, TILs, T-cell inflamed) by MKS/ERS-subgroups. RESULTS: Compared to MKShi/ERShi tumours, MKShi/ERSlo tumours had higher pathological response rates to NAC (22% vs 8%, p = 0.06) but a higher recurrence risk (4-year metastasis-free survival 70% vs 94%, p = 0.01). MKShi/ERSlo tumours frequently harboured TP53 (34%) and PIK3CA (33%) mutations, and showed high expression of Cyclin-E, RBsig and IRPR, high TMB and elevated TIL and T-cell inflamed metagene expression. MKShi/ERSlo tumours retained high proliferation after NET with or without palbociclib but had higher pathological complete response rates when pembrolizumab was added to NAC (42% vs 21%, p = 0.07). CONCLUSIONS: MKShi/ERSlo tumours have dismal outcomes and are enriched in chemotherapy-sensitive but ET- and palbociclib-resistant tumours. Biomarker analysis and clinical data suggest a potential role for immunotherapy in this group.

Pan-cancer analysis of antibody-drug conjugate targets and putative predictors of treatment response.

BACKGROUND: Antibody-drug conjugates (ADCs) are a rapidly expanding class of compounds in oncology. Our goal was to assess the expression of ADC targets and potential downstream determining factors of activity across pan-cancer and normal tissues. MATERIALS AND METHODS: ADCs in clinical trials (n = 121) were identified through ClinicalTrials.gov, corresponding to 54 targets. Genes potentially implicated in treatment response were identified in the literature. Gene expression from The Cancer Genome Atlas (9000+ cancers of 31 cancer types), the Genotype-Tissue Expression database (n = 19,000 samples from 31 normal tissue types), and the TNMplot.com (n = 12,494 unmatched primary and metastatic samples) were used in this analysis. To compare relative expression across and within tumour types we used pooled normal tissues as reference. RESULTS: For most ADC targets, mRNA levels correlated with protein expression. Pan-cancer target expression distributions identified appealing cancer types for each ADC development. Co-expression of multiple targets was common and suggested opportunities for ADC combinations. Expression levels of genes potentially implicated in ADC response downstream of the target might provide additional information (e.g. TOP1 was highly expressed in many tumour types, including breast and lung cancers). Metastatic compared to primary tissues overexpressed some ADCs targets. Single sample "targetgram" plots were generated to visualise the expression of potentially competing ADC targets and resistance/sensitivity markers highlighting high inter-patient heterogeneity. Off-cancer target expression only partially explains adverse events, while expression of determinants of payload activity explained more of the observed toxicities. CONCLUSION: Our findings draw attention to new therapeutic opportunities for ADCs that can be tested in the clinic and our web platform (https://tnmplot.com) can assist in prioritising upcoming ADC targets for clinical development.

Oncotype DX results increase concordance in adjuvant chemotherapy recommendations for early-stage breast cancer.

Adjuvant chemotherapy recommendations for ER+/HER2- early-stage breast cancers (eBC) involve integrating prognostic and predictive information which rely on physician judgment; this can lead to discordant recommendations. In this study we aim to evaluate whether Oncotype DX improves confidence and agreement among oncologists in adjuvant chemotherapy recommendations. We randomly select 30 patients with ER+/HER2- eBC and recurrence score (RS) available from an institutional database. We ask 16 breast oncologists with varying years of clinical practice in Italy and the US to provide recommendation for the addition of chemotherapy to endocrine therapy and their degree of confidence in the recommendation twice; first, based on clinicopathologic features only (pre-RS), and then with RS result (post-RS). Pre-RS, the average rate of chemotherapy recommendation is 50.8% and is higher among junior (62% vs 44%; p < 0.001), but similar by country. Oncologists are uncertain in 39% of cases and recommendations are discordant in 27% of cases (interobserver agreement K 0.47). Post-RS, 30% of physicians change recommendation, uncertainty in recommendation decreases to 5.6%, and discordance decreases to 7% (interobserver agreement K 0.85). Interpretation of clinicopathologic features alone to recommend adjuvant chemotherapy results in 1 out of 4 discordant recommendations and relatively high physician uncertainty. Oncotype DX results decrease discordancy to 1 out of 15, and reduce physician uncertainty. Genomic assay results reduce subjectivity in adjuvant chemotherapy recommendations for ER +/HER2- eBC.

Tissue- and liquid biopsy-based biomarkers for immunotherapy in breast cancer.

Immune checkpoint inhibitors (ICIs) have revolutionized cancer therapy and now represent the mainstay of treatment for many tumor types, including triple-negative breast cancer and two agnostic registrations. However, despite impressive durable responses suggestive of an even curative potential in some cases, most patients receiving ICIs do not derive a substantial benefit, highlighting the need for more precise patient selection and stratification. The identification of predictive biomarkers of response to ICIs may play a pivotal role in optimizing the therapeutic use of such compounds. In this Review, we describe the current landscape of tissue and blood biomarkers that could serve as predictive factors for ICI treatment in breast cancer. The integration of these biomarkers in a "holistic" perspective aimed at developing comprehensive panels of multiple predictive factors will be a major step forward towards precision immune-oncology.

The TRAR gene classifier to predict response to neoadjuvant therapy in HER2-positive and ER-positive breast cancer patients: an explorative analysis from the NeoSphere trial.

As most erb-b2 receptor tyrosine kinase 2 (HER2)-positive breast cancer (BC) patients currently receive dual HER2-targeting added to neoadjuvant chemotherapy, improved methods for identifying individual response, and assisting postsurgical salvage therapy, are needed. Herein, we evaluated the 41-gene classifier trastuzumab advantage risk model (TRAR) as a predictive marker for patients enrolled in the NeoSphere trial. TRAR scores were computed from RNA of 350 pre- and 166 post-treatment tumor specimens. Overall, TRAR score was significantly associated with pathological complete response (pCR) rate independently of other predictive clinico-pathological variables. Separate analyses according to estrogen receptor (ER) status showed a significant association between TRAR score and pCR in ER-positive specimens but not in ER-negative counterparts. Among ER-positive BC patients not achieving a pCR, those with TRAR-low scores in surgical specimens showed a trend for lower distant event-free survival. In conclusion, in HER2-positive/ER-positive BC, TRAR is an independent predictor of pCR and represents a promising tool to select patients responsive to anti-HER2-based neoadjuvant therapy and to assist treatment escalation and de-escalation strategies in this setting.

Immunotherapy in Breast Cancer Patients: A Focus on the Use of the Currently Available Biomarkers in Oncology.

Immune Checkpoint Inhibitors (ICIs) have remarkably modified the way solid tumors are managed, including breast cancer. Unfortunately, only a relatively small number of breast cancer patients significantly respond to these treatments. To maximize the immunotherapy benefit in breast cancer, several efforts are currently being put forward for the identification of i) the best therapeutic strategy (i.e. ICI monotherapy or in association with chemotherapy, radiotherapy, or other drugs); ii) optimal timing for administration (e.g. early/advanced stage of disease; adjuvant/ neoadjuvant setting); iii) most effective and reliable predictive biomarkers of response (e.g. tumor-infiltrating lymphocytes, programmed death-ligand 1, microsatellite instability associated with mismatch repair deficiency, and tumor mutational burden). In this article, we review the impacts and gaps in the characterization of immune-related biomarkers raised by clinical and translational research studies with immunotherapy treatments. Particular emphasis has been put on the documented evidence of significant clinical benefits of ICI in different randomized clinical trials, along with preanalytical and analytical issues in predictive biomarkers pathological assessment.

Body mass index, adiposity and tumour infiltrating lymphocytes as prognostic biomarkers in patients treated with immunotherapy: A multi-parametric analysis.

BACKGROUND: We performed a multi-parametric analysis investigating the association between adiposity (as measured using body mass index [BMI] and computed tomography [CT]-based body composition), tumour infiltrating lymphocytes (TILs) and clinical outcomes in patients with advanced-stage cancer treated with immunotherapy in phase I clinical trials. MATERIAL AND METHODS: All consecutive patients (N = 153) with metastatic solid tumours treated within immunotherapy-based phase I clinical trials between August 2014 and May 2019 at our institution were included. Baseline characteristics, BMI, TILs value and CT-assessed fat indices (total fat area [TFA], subcutaneous fat area [SFA] and visceral fat [VFA]) were collected. The primary endpoints were to evaluate the impact of these parameters on overall survival (OS) and progression-free survival (PFS). Kaplan-Meier method and Cox proportional-hazards model were used for survival analyses. RESULTS: At both univariate and multivariate analyses, BMI was not associated with PFS neither when considered as continuous variable (HR 0.90, 95% CI 0.74-1.09, P = 0.28) nor as dichotomous variable (underweight/normal versus overweight/obese) (HR 0.79, 95% CI 0.55-1.14, P = 0.21). Interestingly, patients diagnosed with 'immunogenic' tumours and higher VFA/SFA ratio (1st and 2nd tertile versus 3rd tertile) presented an increased OS (HR 0.88, 95% CI 0.78-1.00, P = 0.047). CONCLUSION: Our analysis showed that patients with tumours that are already known as responsive to ICIs with higher VFA/SFA ratio presented an increased OS. Further studies are needed to elucidate the effect of adiposity on the host immune response to immunotherapy.

Practical classification of triple-negative breast cancer: intratumoral heterogeneity, mechanisms of drug resistance, and novel therapies.

Triple-negative breast cancer (TNBC) is not a unique disease, encompassing multiple entities with marked histopathological, transcriptomic and genomic heterogeneity. Despite several efforts, transcriptomic and genomic classifications have remained merely theoretic and most of the patients are being treated with chemotherapy. Driver alterations in potentially targetable genes, including PIK3CA and AKT, have been identified across TNBC subtypes, prompting the implementation of biomarker-driven therapeutic approaches. However, biomarker-based treatments as well as immune checkpoint inhibitor-based immunotherapy have provided contrasting and limited results so far. Accordingly, a better characterization of the genomic and immune contexture underpinning TNBC, as well as the translation of the lessons learnt in the metastatic disease to the early setting would improve patients' outcomes. The application of multi-omics technologies, biocomputational algorithms, assays for minimal residual disease monitoring and novel clinical trial designs are strongly warranted to pave the way toward personalized anticancer treatment for patients with TNBC.

Pretreatment Blood Parameters Predict Efficacy from Immunotherapy Agents in Early Phase Clinical Trials.

BACKGROUND: Peripheral blood parameters are correlated to immune-checkpoint inhibitor efficacy in solid tumors, such as melanoma and non-small cell lung cancer. Few data are currently available on the prognostic role of these immune-inflammatory biomarkers for other solid tumors and immunotherapy combinations. MATERIAL AND METHODS: From August 2014 to May 2019, 153 patients with metastatic solid tumors were enrolled in phase I clinical trials testing immunotherapy both as single agents and as combinations. Primary endpoint was to evaluate the impact of baseline blood parameters on progression-free survival (PFS) and overall survival (OS). RESULTS: The most common tumor types were gastrointestinal, breast, and gynecological cancers (22.9%, 22.2%, and 15.0%, respectively). Higher lactate dehydrogenase (LDH) and derived neutrophil-to-lymphocyte ratio (dNLR) were independently associated with reduced PFS (hazard ratio [HR], 1.97; 95% confidence interval [CI], 1.30-2.99; p = .001, and HR, 2.29; 95% CI, 1.39-3.77; p = .001, respectively) and reduced OS (HR, 2.04; 95% CI, 1.26-3.28; p = .004, and HR, 2.06; 95% CI, 1.12-3.79; p = .02, respectively). In the subgroup analysis, (single agent vs. combination), patients at "good" (dNLR <3 and LDH < upper limit of normal [ULN]) and "intermediate and poor" (dNLR >3 and/or LDH > ULN) risk had higher and lower PFS, respectively (p for interaction = .002). Conversely, patients receiving monotherapy presented statistically significant difference in OS according to the risk group, whereas this effect was not observed for those treated with combinations (p for interaction = .004). CONCLUSION: Elevated LDH and dNLR are associated with poorer survival outcomes in patients treated with immunotherapy in phase I clinical trials, regardless of tumor type. These parameters represent an easy tool that might be considered as stratification factors in immunotherapy-based clinical trials. IMPLICATIONS FOR PRACTICE: In this retrospective cohort study of 153 patients with metastatic solid tumors treated with immunotherapy in the context of phase I clinical trials, elevated baseline lactate dehydrogenase and derived neutrophil-to-lymphocyte ratio were associated with reduced survival regardless of tumor subtype. If prospectively validated, these parameters might represent low-cost and easy biomarkers that could help patient selection for early phase immunotherapy trials and be applied as a stratification factor in randomized studies testing immunotherapy agents.

Personalized Risk-Benefit Ratio Adaptation of Breast Cancer Care at the Epicenter of COVID-19 Outbreak.

Northern Italy has been one of the European regions reporting the highest number of COVID-19 cases and deaths. The pandemic spread has challenged the National Health System, requiring reallocation of most of the available health care resources to treat COVID-19-positive patients, generating a competition with other health care needs, including cancer. Patients with cancer are at higher risk of developing critical illness after COVID-19 infection. Thus, mitigation strategies should be adopted to reduce the likelihood of infection in all patients with cancer. At the same time, suboptimal care and treatments may result in worse cancer-related outcome. In this article, we attempt to estimate the individual risk-benefit balance to define personalized strategies for optimal breast cancer management, avoiding as much as possible a general untailored approach. We discuss and report the strategies our Breast Unit adopted from the beginning of the COVID-19 outbreak to ensure the continuum of the best possible cancer care for our patients while mitigating the risk of infection, despite limited health care resources. IMPLICATIONS FOR PRACTICE: Managing patients with breast cancer during the COVID-19 outbreak is challenging. The present work highlights the need to estimate the individual patient risk of infection, which depends on both epidemiological considerations and individual clinical characteristics. The management of patients with breast cancer should be adapted and personalized according to the balance between COVID-19-related risk and the expected benefit of treatments. This work also provides useful suggestions on the modality of patient triage, the conduct of clinical trials, the management of an oncologic team, and the approach to patients' and health workers' psychological distress.

Breast implant-associated anaplastic large cell lymphoma: A comprehensive review.

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is a recently recognized non-Hodgkin lymphoma of T-cell origin. Despite the low incidence of this new disease, the increasing use of breast implants for cosmetic or post-mastectomy reconstruction purposes places BIA-ALC as an emerging and compelling medical challenge. The real BIA-ALCL pathogenesis has not been fully uncovered so far, while different putative causal factors have been proposed. Breast implants with textured surfaces seem to be associated with nearly all cases of BIA-ALCL, while the real the risk of disease development has not been well estimated so far. Late onset, persistent seroma around breast implant represents the classical clinical presentation. Most of the BIA-ALCL patients presents with localized disease, which confers an excellent prognosis. Unlike other non-Hodgkin lymphomas, surgical excision of the mass has a key role in the treatment. For patients with advanced and disseminated diseases, the treatment did not differ from other types of T-cell lymphoma. For these reasons, BIA-ALCL represents an emerging disease which requires multidisciplinary team approach to well define diagnostic workup and treatment for each patient. This review article aims to summarize available data on BIA-ALCL. First, we will outline available data on BIA-ALCL epidemiology, pathogenesis, diagnostic work-up, and treatment. Second, we will point out the potential psychological implications as well as the risk of perception distortion for women with breast implants, especially for those with previous breast cancer. Lastly, we will summarize the current national recommendations regarding textured breast implants and discuss the diagnostic-therapeutic algorithm for BIA-ALCL management.

Harmonizing gene signatures to predict benefit from adjuvant chemotherapy in early breast cancer.

PURPOSE OF REVIEW: Breast cancer is a heterogeneous disease, including different subtypes with their own biology, prognosis, clinical characteristics and treatment. To date, traditional clinical and pathological determinants remain the main factors guiding treatment decision-making; however, the development of multigene assays improved the ability to predict the risk of recurrence in patients with early-stage breast cancer. These tools underwent an extensive independent validation and have already been partly incorporated into clinical practice. RECENT FINDINGS: The current article summarizes current evidence for the use of the different genomic assays in clinical practice, their characteristics and validation studies. A few studies comparing available genomic assays revealed that they provide different information with a modest correlation and that they are not interchangeable; other trials are currently ongoing in this setting. SUMMARY: Variability across different gene signatures may be a challenge for the optimal management of the individual patient, hence each assay should be used for the clinical setting in which it has been validated.

What therapies are on the horizon for HER2 positive breast cancer?

Introduction: Despite dramatic improvements in survival achieved with currently available anti-HER2 agents, HER2-positive metastatic breast cancer remains an almost invariably deadly disease, with primary or acquired resistance to HER2-directed agents developing during treatment. Many efforts are focused on identifying new agents that may more effectively inhibit HER2 signaling and on possible combination strategies. Areas covered: This review summarizes the landscape of drugs under development for HER2-positive metastatic breast cancer, as antibody-drug conjugates, monoclonal anti-HER2 antibodies, bispecific antibodies, or novel tyrosine kinase inhibitors. Moreover, available data for possible combination of anti-HER2 drugs and different agents, as immunotherapy, PI3K/mTOR inhibitors, CDK4/6 inhibitors currently under evaluation are reviewed. These strategies may overcome mechanisms of resistance and further improve patient outcomes. Expert opinion: Identification of valuable predictive biomarkers is needed to better inform choice of treatment sequence for the individual patient and limit the financial toxicity of these agents.

The evolving landscape of 'next-generation' immune checkpoint inhibitors: A review.

'First-generation' immune checkpoint inhibitors targeting Cytotoxic T-Lymphocyte Antigen 4 (CTLA4) and Programmed death-ligand 1 (PD(L)1) have undoubtedly revolutionised the treatment of multiple cancers in the advanced setting. Targeting signalling pathways other than core inhibitory modules may strongly impact the outcome of the antitumour immune response. Drugs targeting these pathways ('next-generation' immune modulators, NGIMs) constitute a major frontier in translational research and have generated unprecedented scientific and financial investment. Here, we systematically reviewed published literature, abstracts from major cancer conferences and pharma pipelines to identify NGIMs that have reached clinical development. We identified 107 molecules targeting 16 pathways, which we classified into 6 groups according to function (inhibitory vs stimulatory) and cell of predominant expression (lymphoid, non-lymphoid and natural killer). We identified all registered past and ongoing clinical trials (n = 428). We summarise the preclinical rationale for these targets, extracting translationally relevant information, and review published and preliminary clinical results. Some targets like indoleamine-2,3-dioxygenase 1, lymphocyte activation gene-3 and IL15 have experienced exceptional growth of interest, measured in terms of activated studies and expected patient enrolment over time. We conclude that in this vast and rapidly changing drug development landscape, novel trial designs and better biomarker identification are necessary to optimise resource allocation.

Recent advances in triple negative breast cancer: the immunotherapy era.

BACKGROUND: Several accomplishments have been achieved in triple-negative breast cancer (TNBC) research over the last year. The phase III IMpassion130 trial comparing chemotherapy plus atezolizumab versus chemotherapy plus placebo brought breast cancer into the immunotherapy era. Nevertheless, despite encouraging results being obtained in this trial, many open questions remain. MAIN BODY: A positive overall survival outcome was achieved only in PD-L1+ TNBC patients, suggesting a need to enrich the patient population more likely to benefit from an immunotherapeutic approach. Moreover, it remains unknown whether single-agent immunotherapy might be a good option for some patients. In this context, the discovery and implementation of novel and appropriate biomarkers are required. Focusing on the early onset of TNBC, neoadjuvant trials could represent excellent in vivo platforms to test immunotherapy agents and their potential combinations, allowing the performance of translational studies for biomarker implementation and improved patient selection. CONCLUSION: The aim of our review is to present recent advances in TNBC treatment and to discuss open issues in order to better define potential future directions for immunotherapy in TNBC.

Safety, Tolerability, and Management of Toxic Effects of Phosphatidylinositol 3-Kinase Inhibitor Treatment in Patients With Cancer: A Review.

IMPORTANCE: The phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway, which regulates multiple cellular processes, including metabolism, proliferation, motility, growth, and survival, is one of the most frequently dysregulated pathways in human cancers. The PI3K/AKT/mTOR cascade can be aberrantly activated by multiple factors, including diverse oncogenic genomic alterations in PIK3CA, PIK3R1, PTEN, AKT, TSC1, TSC2, LKB1, MTOR, and other critical genes, which can be used as targets for anticancer therapy. Limited single-agent activity, high levels of toxic effects, and a lack of predictive biomarkers for treatment selection have all been major barriers to the clinical development of these compounds. Many adverse effects are uncommon and have poorly understood mechanisms. An understanding of these toxic effects, as well as a better definition of management guidelines, will be important because more PI3K inhibitors are under development and may soon be incorporated into routine practice. OBSERVATIONS: A search of PubMed, draft prescribing information of currently approved PI3K inhibitors, European Medical Association and US Food and Drug Administration product information, and expert panel opinion on the management of the prominent toxic effects of this class of agents was conducted on August 29, 2018. This article provides an overview of the main toxic effects of PI3K inhibitors reported in clinical trials and a summary of recommendations for identification and management of treatment-emergent toxic effects, including hypoglycemia, cutaneous reactions, pneumonitis, neuropsychiatric effects, hepatotoxic effects, diarrhea, and colitis. Overall, the clinical development of most PI3K inhibitors has been discontinued owing to insufficient activity, problematic toxic effects, and the absence of biomarkers correlated with clinical activity. Knowledge of the isoforms and their distribution in tissue can help clinicians anticipate toxic effects. Notably, novel, more specific inhibitors for individual isoforms of PI3K showed therapeutic activity with improved toxic effect profiles compared with non-isoform-selective agents. CONCLUSIONS AND RELEVANCE: An improved understanding of the complexities of the main toxic-effect mechanisms and their management might open viable paths to advancing PI3K inhibitors from clinical studies to new standard-of-care treatments.

Peptide vaccines in early breast cancer.

The immune system plays a dual role of host-protecting and tumor-promoting, as elegantly expressed by the 'cancer immunoediting' hypothesis. Although breast cancer has not been traditionally considered to be immunogenic, recently there is accumulating and solid evidence on the association between immune system and breast cancer. To mount an effective anti-tumor response, host immunosurveillance must recognize tumor-specific epitopes, thus defining the antigenicity of a tumor. Neoantigens are mutant cancer peptides that arise as terminal products of the expression of somatic cancer mutations. Neoantigens and major histocompatibility complex (MHC) proteins present together to effector cells of the immune system. Neoantigen vaccines have shown promising results in inducing neoantigen-specific T-cell responses. Currently, cancer vaccines are under evaluation in breast cancer to avoid recurrences in patients at high risk despite optimal standard therapy. Given the promise of a very specific long-term antitumor immune response, the development of cancer vaccines continues is of great interest. Combinations of neoantigen vaccines and other immunotherapies are also studied to evade cancer immune escape.