Window of opportunity studies: Do they fulfil our expectations?

Genitourinary cancer neoadjuvant therapies: current and future approaches

Neoadjuvant therapies can improve tolerability, reduce tumor volume to facilitate surgery, and assess subsequent treatment response. Therefore, there is much enthusiasm for expanding the benefits of cancer therapies to the neoadjuvant setting to reduce recurrence and improve survival in patients with localized or locally advanced genitourinary (GU) cancer. This approach is clinically pertinent because these treatments are administered primarily to treatment-naive patients and can elicit the greatest drug response. In addition, the results are not impacted by other anticancer treatments. While neoadjuvant therapies have been the standard treatment for bladder cancer in the past, they are presently restricted to clinical trials for renal and prostate cancer (PCa); however, changes are imminent. Precision neoadjuvant therapies will be ushered in by biomarker-stratified neoadjuvant trials with appropriate survival endpoints and comprehensive correlative and imaging studies. This review discusses neoadjuvant studies in GU malignancies and how they inform future study design considerations.

Attitudes and barriers to participation in window-of-opportunity trials reported by White and Asian/Asian British ethnicity patients who have undergone treatment for endometrial cancer

PURPOSE

Window-of-opportunity trials (WOT) are a study design that have been used to investigate drug activity in endometrial cancer (EC). Recruitment to cancer clinical trials by patients from ethnic minority groups is reported to be lower than for patients of White ethnicity.

METHODS

A verbal questionnaire was conducted with White and Asian/Asian British ethnicity patients who had undergone treatment for EC. Strategic purposeful sampling was used to recruit patients from diverse social/educational backgrounds. Questions explored: background knowledge of clinical research, WOT study design, and views on medications that might be investigated. Thematic analysis was used to explore motivations for WOT participation and perceived barriers.

RESULTS

In total, 21 patients were recruited to the study (15 White and 6 Asian/Asian British). Views on optimum time to receive trial information differed, preferences ranging from 'at the time of diagnosis' to 'a few days after diagnosis'. The choice of medication under investigation had a strong influence on potential willingness to participate, with greater interest reported in medications derived from vitamins or food supplements rather than hormone-based drugs. Potential barriers to participation included concern over potential side-effects and the emotional/physical burden of a cancer diagnosis prior to major surgery.

DISCUSSION

This study provides important insights into patients' views on WOT participation in EC and raises issues that need to be considered for future trial design and participant recruitment materials. The timing and format of study information and type of substance under investigation were factors influencing potential participation. Future studies should consider using multi-lingual visual information videos to address information needs, as this may encourage participation by ethnic minority patients.

AMEERA-4: a randomized, preoperative window-of-opportunity study of amcenestrant versus letrozole in early breast cancer

BACKGROUND

Window-of-opportunity (WOO) studies provide insights into the clinical activity of new drugs in breast cancer.

METHODS

AMEERA-4 (NCT04191382) was a WOO study undertaken to compare the pharmacodynamic effects of amcenestrant, a selective estrogen receptor degrader, with those of letrozole in postmenopausal women with newly diagnosed, operable estrogen receptor-positive, human epidermal growth factor receptor 2-negative (ER+/HER2-) breast cancer. Women were randomized (1:1:1) to receive amcenestrant 400 mg, amcenestrant 200 mg, or letrozole 2.5 mg once daily for 14 days before breast surgery. The primary endpoint was change in Ki67 between baseline and Day 15 (i.e., day of surgery).

RESULTS

Enrollment was stopped early because of slow recruitment, in the context of the COVID-19 pandemic. The modified intent-to-treat population consisted of 95 study participants with baseline and post-treatment Ki67 values, whereas the safety population included 104 participants who had received at least one dose of study medication. Relative change from baseline in Ki67 was - 75.9% (95% confidence interval [CI] - 81.9 to - 67.9) for amcenestrant 400 mg, - 68.2% (- 75.7 to - 58.4) for amcenestrant 200 mg, and - 77.7% (- 83.4 to - 70.0) for letrozole (geometric least-squares mean [LSM] estimates). Absolute change in ER H-score from baseline (LSM estimate) was - 176.7 in the amcenestrant 400 mg arm, - 202.9 in the amcenestrant 200 mg arm, and - 32.5 in the letrozole arm. There were no Grade ≥ 3 treatment-related adverse events.

CONCLUSIONS

Both amcenestrant and letrozole demonstrated antiproliferative activity in postmenopausal women with previously untreated, operable ER+/HER2- breast cancer and had good overall tolerability.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04191382 https://clinicaltrials.gov/ct2/show/NCT04191382 . Registered 9 December 2019.

Optimizing the safety of antibody-drug conjugates for patients with solid tumours

Over the past 5 years, improvements in the design of antibody-drug conjugates (ADCs) have enabled major advances that have reshaped the treatment of several advanced-stage solid tumours. Considering the intended rationale behind the design of ADCs, which is to achieve targeted delivery of cytotoxic molecules by linking them to antibodies targeting tumour-specific antigens, ADCs would be expected to be less toxic than conventional chemotherapy. However, most ADCs are still burdened by off-target toxicities that resemble those of the cytotoxic payload as well as on-target toxicities and other poorly understood and potentially life-threatening adverse effects. Given the rapid expansion in the clinical indications of ADCs, including use in curative settings and various combinations, extensive efforts are ongoing to improve their safety. Approaches currently being pursued include clinical trials optimizing the dose and treatment schedule, modifications of each ADC component, identification of predictive biomarkers for toxicities, and the development of innovative diagnostic tools. In this Review, we describe the determinants of the toxicities of ADCs in patients with solid tumours, highlighting key strategies that are expected to improve tolerability and enable improvements in the treatment outcomes of patients with advanced-stage and those with early stage cancers in the years to come.

Patritumab Deruxtecan in Untreated Hormone Receptor-Positive/HER2-Negative Early Breast Cancer: Final Results from Part A of the Window-of-Opportunity SOLTI TOT-HER3 Pre-Operative Study

BACKGROUND

Patritumab deruxtecan (HER3-DXd) is a HER3-directed antibody-drug conjugate composed of a fully human anti-HER3 monoclonal antibody (patritumab) covalently linked to a topoisomerase I inhibitor payload via a stable, tumor-selective, tetrapeptide-based cleavable linker. TOT-HER3 is a window-of-opportunity study designed to assess the biological activity, measured by CelTIL score [ = -.8 × tumor cellularity (in %) + 1.3 × TILs (in %)], and clinical activity of HER3-DXd during short-term (21 days) pre-operative treatment in patients with primary operable HER2-negative early breast cancer.

PATIENTS AND METHODS

Patients with previously untreated hormone receptor (HR)-positive/HER2-negative tumors were allocated to one of four cohorts according to baseline ERBB3 mRNA expression. All patients received one dose of HER3-DXd 6.4 mg/kg. The primary objective was to evaluate change from baseline in CelTIL score.

RESULTS

Seventy-seven patients were evaluated for efficacy. A significant change in CelTIL score was observed, with a median increase from baseline of 3.5 (interquartile range, -3.8 to 12.7; P=.003). Among patients evaluable for clinical response (n=62), an overall response rate of 45% was observed (tumor measurement by caliper), with a trend toward an increase in CelTIL score among responders compared with non-responders (mean difference, +11.9 vs +1.9). Change in CelTIL score was independent of baseline ERBB3 mRNA and HER3 protein levels. Genomic changes occurred, including switching toward a less proliferative tumor phenotype based on PAM50 subtypes, suppression of cell proliferation genes, and induction of genes associated with immunity. Treatment-emergent adverse events were observed in 96% of patients (14% grade ≥3); most common were nausea, fatigue, alopecia, diarrhea, vomiting, abdominal pain, and neutrophil count decrease.

CONCLUSIONS

A single dose of HER3-DXd was associated with clinical response, increased immune infiltration, suppression of proliferation in HR-positive/HER2-negative early breast cancer, and a tolerable safety profile consistent with previously reported results. These findings support further study of HER3-DXd in early breast cancer.

Improving oncology first-in-human and Window of opportunity informed consent forms through participant feedback

BACKGROUND

Although patient advocates have developed templates for standard consent forms, evaluating patient preferences for first in human (FIH) and window of opportunity (Window) trial consent forms is critical due to their unique risks. FIH trials are the initial use of a novel compound in study participants. In contrast, Window trials give an investigational agent over a fixed duration to treatment naïve patients in the time between diagnosis and standard of care (SOC) surgery. Our goal was to determine the patient-preferred presentation of important information in consent forms for these trials.

METHODS

The study consisted of two phases: (1) analyses of oncology FIH and Window consents; (2) interviews of trial participants. FIH consent forms were analyzed for the location(s) of information stating that the study drug has not been tested in humans (FIH information); Window consents were analyzed for the location(s) of information stating the trial may delay SOC surgery (delay information). Participants were asked about their preferred placement of the information in their own trial's consent form. The location of information in the consent forms was compared to the participants' suggestions for placement.

RESULTS

34 [17 FIH; 17 Window] of 42(81%) cancer patients approached participated. 25 consents [20 FIH; 5 Window] were analyzed. 19/20 FIH consent forms included FIH information, and 4/5 Window consent forms included delay information. 19/20(95%) FIH consent forms contained FIH information in the risks section 12/17(71%) patients preferred the same. Fourteen (82%) patients wanted FIH information in the purpose, but only 5(25%) consents mentioned it there. 9/17(53%) Window patients preferred delay information to be located early in the consent, before the "Risks" section.  3/5(60%) consents did this.

CONCLUSIONS

Designing consents that reflect patient preferences more accurately is essential for ethical informed consent; however, a one-size fits all approach will not accurately capture patient preferences. We found that preferences differed for FIH and Window trial consents, though for both, patients preferred key risk information early in the consent. Next steps include determining if FIH and Window consent templates improve understanding.

Oncology phase I trial design and conduct: time for a change - MDICT Guidelines 2022

In 2021, the Food and Drug Administration Oncology Center of Excellence announced Project Optimus focusing on dose optimization for oncology drugs. The Methodology for the Development of Innovative Cancer Therapies (MDICT) Taskforce met to review and discuss the optimization of dosage for oncology trials and to develop a practical guide for oncology phase I trials. Defining a single recommended phase II dose based on toxicity may define doses that are neither the most effective nor the best tolerated. MDICT recommendations address the need for robust non-clinical data which are needed to inform trial design, as well as an expert team including statisticians and pharmacologists. The protocol must be flexible and adaptive, with clear definition of all endpoints. Health authorities should be consulted early and regularly. Strategies such as randomization, intrapatient dose escalation, and real-world eligibility criteria are encouraged whereas serial tumor sampling is discouraged in the absence of a strong rationale and appropriately validated assay. Endpoints should include consideration of all longitudinal toxicity. The phase I dose escalation trial should define the recommended dose range for later testing in randomized phase II trials, rather than a single recommended phase II dose, and consider scenarios where different populations may require different dosages. The adoption of these recommendations will improve dosage selection in early clinical trials of new anticancer treatments and ultimately, outcomes for patients.

Balancing Risk and Efficiency in Drug Development for Rare and Challenging Tumors: A New Paradigm for Glioma

The process of developing cancer therapies is well established and has enabled the incorporation of many new drugs and classes of agents into the standard of care for common cancers. Clinical drug development is fundamentally different for rare and difficult-to-treat solid tumors, such as glioma or pancreatic cancer. The failure to develop effective new agents for the latter diseases has discouraged the development of therapeutics for these cancers. Using glioma as an example, we describe a process toward obtaining more reliable early-stage signals of drug activity and a process toward translating those signals into clinical benefits with more efficient late-stage development. If linked together, these processes should increase the likelihood of benefit in late-stage settings at a lower cost and encourage more drug development for patients with rare and difficult-to-treat cancers.

Molecular Biomarker Expression in Window of Opportunity Studies for Oestrogen Receptor Positive Breast Cancer-A Systematic Review of the Literature

Simple Summary

Window of opportunity (WoO) trials allow the opportunity to assess the use of drugs in breast cancer research before treatment has commenced. The aim of this review of the literature is to review WoO trials in patients with oestrogen receptor-positive (ER+) breast cancer to help guide treatment. This will be useful for patients who receive drug treatment before surgery, or as an alternative to surgery in older, more frail adults.

Abstract

Window of opportunity (WoO) trials create the opportunity to demonstrate pharmacodynamic parameters of a drug in vivo and have increasing use in breast cancer research. Most breast cancer tumours are oestrogen receptor-positive (ER+), leading to the development of multiple treatment options tailored towards this particular tumour subtype. The aim of this literature review is to review WoO trials pertaining to the pharmacodynamic activity of drugs available for use in ER+ breast cancer in order to help guide treatment for patients receiving neoadjuvant and primary endocrine therapy. Five databases (EMBASE, Cochrane, MEDLINE, PubMed, Web of Science) were searched for eligible studies. Studies performed in treatment-naïve patients with histologically confirmed ER+ breast cancer were included if they acquired pre- and post-treatment biopsies, compared measurement of a proteomic biomarker between these two biopsies and delivered treatment for a maximum mean duration of 31 days. Fifteen studies were eligible for inclusion and covered six different drug classes: three endocrine therapies (ETs) including aromatase inhibitors (AIs), selective oestrogen receptor modulators (SERMs), selective oestrogen receptor degraders (SERDs) and three non-ETs including mTOR inhibitors, AKT inhibitors and synthetic oestrogens. Ki67 was the most frequently measured marker, appearing in all studies. Progesterone receptor (PR) and ER were the next most frequently measured markers, appearing five and four studies, respectively. All three of these markers were significantly downregulated in both AIs and SERDs; Ki67 alone was downregulated in SERMs. Less commonly assessed markers including pS6, pGSH3B, FSH and IGF1 were downregulated while CD34, pAKT and SHBG were significantly upregulated. There were no significant changes in the other biomarkers measured such as phosphate and tensin homolog (PTEN), Bax and Bcl-2.WoO studies have been widely utilised within the ER+ breast cancer subtype, demonstrating their worth in pharmacodynamic research. However, research remains focused upon routinely measured biomarkers such ER PR and Ki67, with an array of less common markers sporadically used.

Early [18]FDG PET/CT scan predicts tumor response in head and neck squamous cell cancer patients treated with erlotinib adjusted per smoking status

Translational Relevance

Evaluation of targeted therapies is urgently needed for the majority of patients with metastatic/recurrent head and neck squamous cell carcinoma (HNSCC) who progress after immunochemotherapy. Erlotinib, a targeted inhibitor of epidermal growth factor receptor pathway, lacks FDA approval in HNSCC due to inadequate tumor response. This study identifies two potential avenues to improve tumor response to erlotinib among patients with HNSCC. For the first time, this study shows that an increased erlotinib dose of 300 mg in smokers is well-tolerated and produces similar plasma drug concentration as the regular dose of 150 mg in non-smokers, with increased study-specific defined tumor response. The study also highlights the opportunity for improved patient selection for erlotinib treatment by demonstrating that early in-treatment [18]FDG PET/CT is a potential predictor of tumor response, with robust statistical correlations between metabolic changes on early in-treatment PET (4-7 days through treatment) and anatomic response measured by end-of-treatment CT.

Purpose

Patients with advanced HNSCC failing immunochemotherapy have no standard treatment options. Accelerating the investigation of targeted drug therapies is imperative. Treatment with erlotinib produced low response rates in HNSCC. This study investigates the possibility of improved treatment response through patient smoking status-based erlotinib dose optimization, and through early in-treatment [18]FDG PET evaluation to differentiate responders from non-responders.

Experimental design

In this window-of-opportunity study, patients with operable HNSCC received neoadjuvant erlotinib with dose determined by smoking status: 150 mg (E150) for non-smokers and 300 mg (E300) for active smokers. Plasma erlotinib levels were measured using mass spectrometry. Patients underwent PET/CT before treatment, between days 4-7 of treatment, and before surgery (post-treatment). Response was measured by diagnostic CT and was defined as decrease in maximum tumor diameter by ≥ 20% (responders), 10-19% (minimum-responders), and < 10% (non-responders).

Results

Nineteen patients completed treatment, ten of whom were smokers. There were eleven responders, five minimum-responders, and three non-responders. Tumor response and plasma erlotinib levels were similar between the E150 and E300 patient groups. The percentage change on early PET/CT and post-treatment PET/CT compared to pre-treatment PET/CT were significantly correlated with the radiologic response on post-treatment CTs: R=0.63, p=0.0041 and R=0.71, p=0.00094, respectively.

Conclusion

This pilot study suggests that early in-treatment PET/CT can predict response to erlotinib, and treatment with erlotinib dose adjusted according to smoking status is well-tolerated and may improve treatment response in HNSCC. These findings could help optimize erlotinib treatment in HNSCC and should be further investigated.

Clinical Trial Registration

https://clinicaltrials.gov/ct2/show/NCT00601913, identifier NCT00601913.

Patient perspectives on window of opportunity clinical trials in early-stage breast cancer

PURPOSE

Window of opportunity trials (WOT) are increasingly common in oncology research. In WOT participants receive a drug between diagnosis and anti-cancer treatment, usually for the purpose of investigating that drugs effect on cancer biology. This qualitative study aimed to understand patient perspectives on WOT.

METHODS

We recruited adults diagnosed with early-stage breast cancer awaiting definitive therapy at a single-academic medical center to participate in semi-structured interviews. Thematic and content analyses were performed to identify attitudes and factors that would influence decisions about WOT participation.

RESULTS

We interviewed 25 women diagnosed with early-stage breast cancer. The most common positive attitudes toward trial participation were a desire to contribute to research and a hope for personal benefit, while the most common concerns were the potential for side effects and how they might impact fitness for planned treatment. Participants indicated family would be an important normative factor in decision-making and, during the COVID-19 pandemic, deemed the absence of family members during clinic visits a barrier to enrollment. Factors that could hinder participation included delay in standard treatment and the requirement for additional visits or procedures. Ultimately, most interviewees stated they would participate in a WOT if offered (N = 17/25).

CONCLUSION

In this qualitative study, interviewees weighed altruism and hypothetical personal benefit against the possibility of side effect from a WOT. In-person family presence during trial discussion, challenging during COVID-19, was important for many. Our results may inform trial design and communication approaches in future window of opportunity efforts.

A Window of Opportunity to Overcome Therapeutic Failure in Neuro-Oncology

Glioblastoma is the most common primary malignant brain neoplasm and it remains one of the most difficult-to-treat human cancers despite decades of discovery and translational and clinical research. Many advances have been made in our understanding of the genetics and epigenetics of gliomas in general; yet, there remains an urgent need to develop novel agents that will improve the survival of patients with this deadly disease. What sets glioblastoma apart from all other cancers is that it develops and spreads within an organ that renders tumor cells inaccessible to most systemically administered agents because of the presence of the blood-brain barrier. Inadequate drug penetration into the central nervous system is often cited as the most common cause of trial failure in neuro-oncology, and even so-called brain-penetrant therapeutics may not reach biologically relevant concentrations in tumor cells. Evaluation of the pharmacokinetics and pharmacodynamics of a novel therapy is a cornerstone of drug development, but few trials for glioma therapeutics have incorporated these basic elements in an organ-specific manner. Window-of-opportunity clinical trial designs can provide early insight into the biological plausibility of a novel therapeutic strategy in the clinical setting. A variety of window-of-opportunity trial designs, which take into account the limited access to treated tissue and the challenges with obtaining pretreatment control tissues, have been used for the initial development of traditional and targeted small-molecule drugs and biologic therapies, including immunotherapies and oncolytic viral therapies. Early-stage development of glioma therapeutics should include a window-of-opportunity component whenever feasible.

Characterization of anticancer drug resistance by reverse-phase protein array: new targets and strategies

INTRODUCTION

Drug resistance is the main barrier to achieving cancer cures with medical therapy. Cancer drug resistance occurs, in part, due to adaptation of the tumor and microenvironment to therapeutic stress at a proteomic level. Reverse-phase protein arrays (RPPA) are well suited to proteomic analysis of drug resistance due to high sample throughput, sensitive detection of phosphoproteins, and validation for a large number of critical cellular pathways.

AREAS COVERED

This review summarizes contributions of RPPA to understanding and combating drug resistance. In particular, contributions of RPPA to understanding resistance to PARP inhibitors, BRAF inhibitors, immune checkpoint inhibitors, and breast cancer investigational therapies are discussed. Articles reviewed were identified by MEDLINE, Scopus, and Cochrane search for keywords 'proteomics,' 'reverse-phase protein array,' 'drug resistance,' 'PARP inhibitor,' 'BRAF inhibitor,' 'immune checkpoint inhibitor,' and 'I-SPY' spanning October 1, 1960 - October 1, 2021.

EXPERT OPINION

Precision oncology has thus far failed to convert the armament of targeted therapies into durable responses for most patients, highlighting that genetic sequencing alone is insufficient to guide therapy selection and overcome drug resistance. Combined genomic and proteomic analyses paired with creative drug combinations and dosing strategies hold promise for maturing precision oncology into an era of improved patient outcomes.

Vaccine-Based Immunotherapy for Head and Neck Cancers

Simple Summary

Therapeutic vaccines are given to patients with cancer, as opposed to prophylactic vaccines given to a healthy population. The challenge for therapeutic oncological vaccines is to stimulate an immune T cell response against endogenous (or derived) antigens that is sufficiently potent to induce cytotoxic activity and broad enough to take tumor heterogeneity into account. The purpose of this article is to provide an updated review of the prophylactic and therapeutic vaccines that target viral or non-viral antigens, particularly in head and neck cancers.

Abstract

In 2019, the FDA approved pembrolizumab, a monoclonal antibody targeting PD-1, for the first-line treatment of recurrent or metastatic head and neck cancers, despite only a limited number of patients benefiting from the treatment. Promising effects of therapeutic vaccination led the FDA to approve the use of the first therapeutic vaccine in prostate cancer in 2010. Research in the field of therapeutic vaccination, including possible synergistic effects with anti-PD(L)1 treatments, is evolving each year, and many vaccines are in pre-clinical and clinical studies. The aim of this review article is to discuss vaccines as a new therapeutic strategy, particularly in the field of head and neck cancers. Different vaccination technologies are discussed, as well as the results of the first clinical trials in HPV-positive, HPV-negative, and EBV-induced head and neck cancers.

Guidelines for clinical evaluation of anti-cancer drugs

Clinical studies intended for regulatory approval must demonstrate the clinical benefits of the drug in a target population. Clinical development of a drug proceeds by stepwise clinical studies; after safety and pharmacokinetics are evaluated and the recommended dosage and administration are determined, efficacy and safety are evaluated in an exploratory manner, and finally clinical benefits are compared with conventional standard therapies. Guidelines for the clinical evaluation of anti‐cancer drugs in Japan were established in 1991 and amended in 2006 after molecular‐targeted drugs were introduced. Recent progress in the development of drugs acting on the immune system and cancer genomic medicine targeting rare but important molecular subtypes have altered the strategy for development of anti‐cancer drugs. It is often difficult to conduct a confirmatory randomized controlled study using overall survival as the primary endpoint in rare molecular subtypes, and the primary evaluation of the efficacy of some drugs and subsequent approval is based on the tumor response. As conducting clinical studies for rare subtypes solely within Japan is difficult, drug development needs to be conducted within a global study. However, this requires robust monitoring to detect possible ethnic differences in pharmacokinetics and drug efficacy. Development using the conditional approval system for drugs enforced in 2020 may be considered, when clinical utility is evaluated based on surrogate endpoints. Because of these changes, we have revised the guidelines for the clinical evaluation of anti‐cancer drugs in Japan. To promote global development of anti‐cancer drugs involving Japan, the guidelines have been translated into English.

Recent progress in development of drugs acting on the immune system and cancer genomic medicine targeting rare but important molecular subtypes have altered the strategy for development of anti‐cancer drugs. As conducting clinical studies for rare subtypes solely within Japan is difficult, drug development needs to be conducted within a global study with monitoring possible ethnic differences. Because of these changes, we have revised the guidelines for the clinical evaluation of anti‐cancer drugs in Japan.

Window of Opportunity Clinical Trials to Evaluate Novel Therapies for Brain Tumors

Despite significant improvement in understanding of molecular underpinnings driving glioblastoma, there is minimal improvement in overall survival of patients. This poor outcome is caused in part by traditional designs of early phase clinical trials, which focus on clinical assessments of drug toxicity and response. Window of opportunity trials overcome this shortcoming by assessing drug-induced on-target molecular alterations in post-treatment human tumor specimens. This article provides an overview of window of opportunity trials, including novel designs for incorporating biologic end points into early stage trials in context of brain tumors, and examples of successfully executed window of opportunity trials for glioblastoma.

Data-independent acquisition mass spectrometry (DIA-MS) for proteomic applications in oncology

Data-independent acquisition mass spectrometry (DIA-MS) is a next generation proteomic methodology that generates permanent digital proteome maps offering highly reproducible retrospective analysis of cellular and tissue specimens. The adoption of this technology has ushered a new wave of oncology studies across a wide range of applications including its use in molecular classification, oncogenic pathway analysis, drug and biomarker discovery and unravelling mechanisms of therapy response and resistance. In this review, we provide an overview of the experimental workflows commonly used in DIA-MS, including its current strengths and limitations versus conventional data-dependent acquisition mass spectrometry (DDA-MS). We further summarise a number of key studies to illustrate the power of this technology when applied to different facets of oncology. Finally we offer a perspective of the latest innovations in DIA-MS technology and machine learning-based algorithms necessary for driving the development of high-throughput, in-depth and reproducible proteomic assays that are compatible with clinical diagnostic workflows, which will ultimately enable the delivery of precision cancer medicine to achieve optimal patient outcomes.

Sensitizing the Tumor Microenvironment to Immune Checkpoint Therapy

Immune checkpoint blockade (ICB) has revolutionized cancer treatment, providing remarkable clinical responses in some patients. However, the majority of patients do not respond. It is therefore crucial both to identify predictive biomarkers of response and to increase the response rates to immune checkpoint therapy. In this review we explore the current literature about the predictive characteristics of the tumor microenvironment and discuss therapeutic approaches that aim to change this toward a milieu that is conducive to response. We propose a personalized biomarker-based adaptive approach to immunotherapy, whereby a sensitizing therapy is tailored to the patient's specific tumor microenvironment, followed by on-treatment verification of a change in the targeted biomarker, followed by immune checkpoint therapy. By incorporating detailed knowledge of the immunological tumor microenvironment, we may be able to sensitize currently non-responsive tumors to respond to immune checkpoint therapy.

Window of opportunity treatment in breast cancer

Window of opportunity therapies, which involve short-term administration of systemic therapy between cancer diagnosis and surgery, have raised significant interest in recent years as a mean of assessing the sensitivity of a patient's cancer to therapy prior to surgery. There is now compelling evidence that in patients with early stage hormone-receptor positive breast cancer, a 2-week preoperative treatment with standard hormone therapies in a preoperative window period provides important prognostic information, which in turn helps to aid decision-making regarding treatment options. Changes in short-term biomarker endpoints such as cell proliferation measured by Ki-67 can act as surrogate markers of long-term outcomes. Paired tissues obtained pre- and post-investigational treatment, without having to subject the patient to additional biopsies, can then be used to conduct translational research to investigate predictive biomarkers and pharmacodynamics. In this review, we will examine the utility and challenges of window of opportunities therapies in breast cancer in the current literature, and the current Australian and international trial landscape in this clinical space.

Epigenetic modifiers as new immunomodulatory therapies in solid tumours

Background

Immune therapies have revolutionized cancer treatment over the last few years by allowing improvements in overall survival. However, the majority of patients is still primary or secondary resistant to such therapies, and enhancing sensitivity to immune therapies is therefore crucial to improve patient outcome. Several recent lines of evidence suggest that epigenetic modifiers have intrinsic immunomodulatory properties, which could be of therapeutic interest.

Material and methods

We reviewed preclinical evidence and clinical studies which describe or exploit immunomodulatory properties of epigenetic agents. Experimental approaches, clinical applicability and corresponding ongoing clinical trials are described.

Results

Several epigenetic modifiers, such as histone deacetylase inhibitors, DNA methyl transferase inhibitors, bromodomain inhibitors, lysine-specific histone demethylase 1 inhibitors and enhancer of zeste homolog 2 inhibitors, display intrinsic immunomodulatory properties. The latter can be achieved through the action of these drugs either on cancer cells (e.g. presentation and generation of neoantigens, induction of immunogenic cell death, modulation of cytokine secretion), on immune cells (e.g. linage, differentiation, activation status and antitumor capability), or on components of the microenvironment (e.g. regulatory T cells and macrophages). Several promising combinations, notably with immune checkpoint blockers or adoptive T-cell therapy, can be envisioned. Dedicated clinically relevant approaches for patient selection and trial design will be required to optimally develop such combinations.

Conclusion

In an era where immune therapies are becoming a treatment backbone in many tumour types, epigenetic modifiers could play a crucial role in modulating tumours' immunogenicity and sensitivity to immune agents. Optimal trial design, including window of opportunity trials, will be key in the success of this approach, and clinical evaluation is ongoing.

Randomized window of opportunity trial evaluating high-dose vitamin D in breast cancer patients

PURPOSE

Epidemiologic and preclinical data suggest a potential role for vitamin D in breast cancer treatment and prevention. However, results of prospective randomized trials are inconsistent. The objective of this study was to assess the effects of high-dose cholecalciferol (vitamin D3) on breast tumour proliferation and apoptosis.

METHODS

We conducted a prospective, randomized, phase 2, double-blinded pre-surgical window of opportunity trial. Newly diagnosed breast cancer patients were randomized to receive 40,000 IU of vitamin D3 per day or placebo for 2 to 6 weeks prior to breast surgery. The primary outcome was the relative change in proliferation (Ki67) and apoptosis (cleaved caspase 3 apoptotic assay [CC3]) in primary breast cancer cells pre and post treatment.

RESULTS

Of 83 patients randomized, 80 completed the study (43 (53.8%) vitamin D and 37 (46.3%) placebo). Mean duration of drug intake was 19 days (range 9-28 days). There were no significant differences between the control arm and the vitamin D arm in percent changes of either Ki67 index (1.6% vs. 16.7%, p = 0.25) or CC3 (- 55.9% vs. - 45.9%, p = 0.28). Serum 25-hydroxyvitamin D (25-OHD) levels were 3 times higher in the vitamin D arm (62 nmol/L vs. 246 nmol/L, p < 0.001). Adverse effects were minimal and all classified as grade 1.

CONCLUSIONS

Despite significantly higher levels of serum 25-OHD in the vitamin D-treated group, this was not associated with any significant effects on tumour proliferation or apoptosis. These findings are consistent with the lack of benefit observed in prospective prevention trials.

TRIAL REGISTRY

Trial registration clinicaltrials.gov NCT01948128.

A randomized, double-blind, window of opportunity trial evaluating the effects of chloroquine in breast cancer patients

PURPOSE

Chloroquine has demonstrated anti-tumor activities through autophagy inhibition and cell cycle disruption. This study aimed to assess the effect of single-agent chloroquine on breast tumor cellular proliferation in a randomized, phase II, double-blind, placebo-controlled, pre-surgical window of opportunity trial.

METHODS

Patients with newly diagnosed breast cancer were randomized 2:1 to chloroquine 500 mg daily or placebo for 2- to 6-weeks prior to their breast surgery. The primary outcome was the relative change in measures of proliferation (Ki67) in primary breast cancer cells pre- and post-treatment. Adverse events and toxicity profiles were also evaluated.

RESULTS

From September 2015 to December 2016, 70 patients were randomized [46 (66%) chloroquine and 24 (34%) placebo]. Ten patients who were randomized to chloroquine withdrew from study due to adverse events. Mean duration of drug intake was 15 days (range 14-29 days). There were no significant differences between the chloroquine or placebo arms with respect to either the percentage change (- 0.4 vs. - 1.2, p = 0.088) or absolute change (- 2.0% vs. - 5.2%, p = 0.066) in Ki67 index pre- and post-drug treatment. Although adverse effects were minimal and all classified as grade 1, the effects were significant enough to cause nearly 15% of patients to discontinue therapy.

CONCLUSIONS

Treatment with single-agent chloroquine 500 mg daily in the preoperative setting was not associated with any significant effects on breast cancer cellular proliferation. It was, however, associated with toxicity that may affect its broader use in oncology.

Window of opportunity trials in head and neck cancer

Head and neck squamous cell carcinoma (HNSCC) has a large global burden of disease and poor survival outcomes. Recent targeted therapies and immunotherapies have been explored in HNSCC, but there has been limited translation to clinical practice outside of recurrent or metastatic cases. Window of opportunity settings, where novel agents are administered between cancer diagnosis and planned definitive therapy, have begun to be employed in HNSCC. Tumor tissue biopsies are obtained at diagnosis and after the investigation treatment, along with other biospecimens and radiographic exams. Thus, this study design can characterize the safety profiles, pharmacodynamics, and initial tumor responses to novel therapies in a treatment-naïve subject. Early window studies have also identified potential biomarkers to predict sensitivity or resistance to treatments. However, these early investigations have revealed multiple challenges associated with this trial design. In this review, we discuss recent window of opportunity trials in HNSCC and how they inform design considerations for future studies.

Adaptive responses in a PARP inhibitor window of opportunity trial illustrate limited functional interlesional heterogeneity and potential combination therapy options

Poly (ADP-ribose) polymerase inhibitor (PARPi)-based combination therapies are demonstrating efficacy in patients, however, identifying the right combination for the right patient remains a critical challenge. Thus, it is urgent to develop approaches able to identify patients likely to benefit from specific combination therapies. Several groups, including ours, have demonstrated that targeting adaptive responses induced by PARPi increases depth and duration of response. In this study, we instituted a talazoparib (PARPi) monotherapy window of opportunity trial to identify informative adaptive responses in high grade serous ovarian cancer patients (HGSOC). Patients were treated for 7 to 14 days with PARPi monotherapy prior to surgery with tissue samples from multiple sites being collected pre- and post-treatment in each patient. Analysis of these samples demonstrated that individual patients displayed different adaptive responses with limited interlesional heterogeneity. Ability of combination therapies designed to interdict adaptive responses to decrease viability was validated using model systems. Thus, assessment of adaptive responses to PARPi provides an opportunity for patient-specific selection of combination therapies designed to interdict patient-specific adaptive responses to maximize patient benefit.

Proteomics and phosphoproteomics in precision medicine: applications and challenges

Recent advances in proteomics allow the accurate measurement of abundances for thousands of proteins and phosphoproteins from multiple samples in parallel. Therefore, for the first time, we have the opportunity to measure the proteomic profiles of thousands of patient samples or disease model cell lines in a systematic way, to identify the precise underlying molecular mechanism and discover personalized biomarkers, networks and treatments. Here, we review examples of successful use of proteomics and phosphoproteomics data sets in as well as their integration other omics data sets with the aim of precision medicine. We will discuss the bioinformatics challenges posed by the generation, analysis and integration of such large data sets and present potential reasons why proteomics profiling and biomarkers are not currently widely used in the clinical setting. We will finally discuss ways to contribute to the better use of proteomics data in precision medicine and the clinical setting.

The evolving role of immuno-oncology for the treatment of head and neck cancer

Monoclonal antibodies (mAbs) that target immune co‐signaling pathways have the potential to enable immune mediated tumor eradication. While early adoption of these agents for the treatment of advanced squamous cell carcinoma of the head and neck (SCCHN) has produced some astounding clinical successes, the majority of patients fail to respond to therapy. The purpose of this review is to first provide a broad overview of the immuno‐oncology (I‐O) landscape and to then focus on the current status of mAb‐based I‐O (mAb:I‐O) for the treatment of SCCHN, with particular attention to the development of strategies for improving treatment responses.

Window Studies in Squamous Cell Carcinoma of the Head and Neck: Values and Limits

OPINION STATEMENT

In head and neck cancer, we continue to work towards a more personalized approach to treatment of patients, where analysis of a patient's tumor guides targeting of molecular or immunologic pathways. Critically important to this pursuit is a better understanding of the direct biologic effect of a drug or combination on the tumor microenvironment in humans, as well as biomarker discovery. These goals are consistent with the primary purpose of a "window of opportunity" trial and while conduct of these trials requires a careful balance of benefits and potential risks, to date these trials have been both feasible and safe in HNSCC in the curative intent setting. In the era of immunotherapy, with countless possible combinations and ongoing clinical trials, window trials are even more important for informing clinical trial design and appropriate combination therapy, and ultimately a more personalized approach to our patients that leads to improvement in outcomes.

Moving forward with actionable therapeutic targets and opportunities in endometrial cancer: A NCI clinical trials planning meeting report

The incidence of endometrial cancer (EC) in the U.S. has been rising, from an estimated annual incidence of 49,560 in 2013 to 61,380 in 2017. Meanwhile, the SEER-based relative survival of women with EC in the U.S. has remained flat [82.3% from 1987 to 1989, 82.8% from 2007 to 2013] and our recent increased understanding of EC biology and subtypes has not been translated into therapeutic advances. The U.S. National Cancer Institute (NCI) therefore convened a Uterine Clinical Trials Planning Meeting in January 2016 to initiate and accelerate design of molecularly-targeted EC trials. Prior to the meeting a group of experts in this field summarized available data, emphasizing data on human samples, to identify potentially actionable alterations in EC, and the results of their work has been separately published. The Clinical Trials Meeting planners focused on discussion of (1) novel trial designs, including window-of opportunity trials and appropriate control groups for randomized trials, (2) targets specific to serous carcinoma and promises and pitfalls of separate trials for women with tumors of this histology (3) specific recommendations for future randomized trials.

Trends in Surgical Research in Head and Neck Cancer

OPINION STATEMENT

The task of surgical research is to improve the efficacy of available surgical therapeutic modalities, develop new ones, and balance this well with favorable functional outcome. Therefore, surgical research is composed of a translational and a clinical component. In translational surgical research, animal models are used to better understand the biology of head and neck cancers, but even more importantly, the biology of changes to the disease and the microenvironment created by surgical interventions. Animal models additionally allow for the development of image-guided surgery systems, novel strategies of intraoperative adjuvant treatment, and patient "avatars" to test innovative anticancer drug combinations. In clinical surgical research, surgical techniques are validated in clinical trials for effectiveness of tumor control and improvement of functional recovery of the patient. In conclusion, surgical research for head and neck cancer is an active field spanning across the entire breadth of basic and clinical science devoted to a better understanding of what surgery does to the disease and to the patient.

Ribociclib plus letrozole in early breast cancer: A presurgical, window-of-opportunity study

OBJECTIVES

Cyclin D-cyclin-dependent kinase (CDK) 4/6-inhibitor of CDK4/6-retinoblastoma (Rb) pathway hyperactivation is associated with hormone receptor-positive (HR+) breast cancer (BC). This study assessed the biological activity of ribociclib (LEE011; CDK4/6 inhibitor) plus letrozole compared with single-agent letrozole in the presurgical setting.

MATERIALS AND METHODS

Postmenopausal women (N = 14) with resectable, HR+, human epidermal growth factor receptor 2-negative (HER2-) early BC were randomized 1:1:1 to receive 2.5 mg/day letrozole alone (Arm 1), or with 400 or 600 mg/day ribociclib (Arm 2 or 3). Circulating tumor DNA and tumor biopsies were collected at baseline and, following 14 days of treatment, prior to or during surgery. The primary objective was to assess antiproliferative response per Ki67 levels in Arms 2 and 3 compared with Arm 1. Additional assessments included safety, pharmacokinetics, and genetic profiling.

RESULTS

Mean decreases in the Ki67-positive cell fraction from baseline were: Arm 1 69% (range 38-100%; n = 2), Arm 2 96% (range 78-100%; n = 6), Arm 3 92% (range 75-100%; n = 3). Decreased phosphorylated Rb levels and CDK4, CDK6, CCND2, CCND3, and CCNE1 gene expression were observed following ribociclib treatment. Ribociclib and letrozole pharmacokinetic parameters were consistent with single-agent data. The ribociclib plus letrozole combination was well tolerated, with no Grade 3/4 adverse events over the treatment.

CONCLUSION

The results suggest absence of a drug-drug interaction between ribociclib and letrozole and indicate ribociclib plus letrozole may reduce Ki67 expression in HR+, HER2- BC (NCT01919229).