This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Background Homologous recombination deficiency (HRD) is a phenotype that is characterized by the inability of a cell to effectively repair DNA double-strand breaks using the homologous recombination repair (HRR) pathway. Loss-of-function genes involved in this pathway can sensitize tumors to poly(adenosine diphosphate [ADP]-ribose) polymerase (PARP) inhibitors and platinum-based chemotherapy, which target the destruction of cancer cells by working in concert with HRD through synthetic lethality. However, to identify patients with these tumors, it is vital to understand how to best measure homologous repair (HR) status and to characterize the level of alignment in these measurements across different diagnostic platforms. A key current challenge is that there is no standardized method to define, measure, and report HR status using diagnostics in the clinical setting. Methods Friends of Cancer Research convened a consortium of project partners from key healthcare sectors to address concerns about the lack of consistency in the way HRD is defined and methods for measuring HR status. Results This publication provides findings from the group’s discussions that identified opportunities to align the definition of HRD and the parameters that contribute to the determination of HR status. The consortium proposed recommendations and best practices to benefit the broader cancer community. Conclusion Overall, this publication provides additional perspectives for scientist, physician, laboratory, and patient communities to contextualize the definition of HRD and various platforms that are used to measure HRD in tumors.

Purpose: Restrictive clinical trial eligibility criteria (EC) limit the number of patients who can enroll and potentially benefit from protocol-driven, investigational treatment plans and reduce the generalizability of trial results to the broader population. Following publication of expert stakeholder recommendations for broadening EC in 2017, the American Society of Clinical Oncology (ASCO) and Friends of Cancer Research (Friends) convened working groups to produce additional recommendations and analyze the potential impact on clinical trials using real-world data. Experimental Design: Multistakeholder working groups were appointed by an ASCO-Friends leadership group to propose recommendations for more inclusive EC related to: washout periods, concomitant medications, prior therapies, laboratory reference ranges and test intervals, and performance status. Results: The four working groups, ASCO Board of Directors, and Friends leadership support the recommendations included in this statement to modernize EC related to washout periods, concomitant medications, prior therapies, laboratory references ranges and test intervals, and performance status to make trial populations more inclusive and representative of cancer patient populations. Conclusions: Implementation of the recommendations is intended to result in greater ease of determining patient eligibility. Increased opportunities for patient participation in research will help address longstanding underrepresentation of certain groups in clinical trials and produce evidence that is more informative for a broader patient population. More patients eligible will also likely speed clinical trial accrual. See related commentary by Giantonio, p. 2369

PURPOSE As immune checkpoint inhibitors (ICI) become increasingly used in frontline settings, identifying early indicators of response is needed. Recent studies suggest a role for circulating tumor DNA (ctDNA) in monitoring response to ICI, but uncertainty exists in the generalizability of these studies. Here, the role of ctDNA for monitoring response to ICI is assessed through a standardized approach by assessing clinical trial data from five independent studies. PATIENTS AND METHODS Patient-level clinical and ctDNA data were pooled and harmonized from 200 patients across five independent clinical trials investigating the treatment of patients with non–small-cell lung cancer with programmed cell death-1 (PD-1)/programmed death ligand-1 (PD-L1)–directed monotherapy or in combination with chemotherapy. CtDNA levels were measured using different ctDNA assays across the studies. Maximum variant allele frequencies were calculated using all somatic tumor-derived variants in each unique patient sample to correlate ctDNA changes with overall survival (OS) and progression-free survival (PFS). RESULTS We observed strong associations between reductions in ctDNA levels from on-treatment liquid biopsies with improved OS (OS; hazard ratio, 2.28; 95% CI, 1.62 to 3.20; P < .001) and PFS (PFS; hazard ratio 1.76; 95% CI, 1.31 to 2.36; P < .001). Changes in the maximum variant allele frequencies ctDNA values showed strong association across different outcomes. CONCLUSION In this pooled analysis of five independent clinical trials, consistent and robust associations between reductions in ctDNA and outcomes were found across multiple end points assessed in patients with non–small-cell lung cancer treated with an ICI. Additional tumor types, stages, and drug classes should be included in future analyses to further validate this. CtDNA may serve as an important tool in clinical development and an early indicator of treatment benefit.

Purpose: Restrictive eligibility criteria induce differences between clinical trial and 'real-world' treatment populations. Restrictions based on prior therapies are common; minimizing them when appropriate may increase patient participation in clinical trials.

Introduction: Treatment decisions in older adults with acute myeloid leukemia (AML) are challenging, particularly for those who are not candidates for intensive chemotherapy (IC), and the trade-offs patients, their families and physicians consider when choosing a treatment option are not well understood. This qualitative research explored the value of extending survival and the treatment decision-making process from a multi-stakeholder perspective. Methods: Overall, 28 patients with AML (C 65 years old, unsuitable for IC), 25 of their relatives and 10 independent physicians from the US, UK and Canada took part in one-onone, 60-minute qualitative interviews.Results: Across all stakeholders, improved health-related quality of life (HRQoL), extended survival and relief of AML symptoms were rec-

<p>Figure S4 shows the expression of MYC and Ki67 by immunohistochemistry in human choroid plexus carcinoma patient specimens.</p>

<p>Figure S3 shows lineage tracing of Blbp+ progenitors in the choroid plexus of the lateral ventricle and 4th ventricle of the mouse brain.</p>