Citations

Abstract Time to progression of disease (POD) after first-line (1L) therapy is prognostic in mantle cell lymphoma (MCL), although studies have included a broad range of 1L, second-line (2L), and subsequent lines of therapy. The purpose of this study was to evaluate the factors predicting outcomes in patients with relapsed/refractory (R/R) MCL exclusively initiating 2L Bruton’s tyrosine kinase inhibitors (BTKis) after 1L rituximab-containing therapy. Patients were accrued from 8 international centers (7 main, 1 validation cohort). Multivariable models evaluating the association between time to POD and clinical/pathologic factors were constructed and converted into nomograms and prognostic indexes predicting outcomes in this population. A total of 360 patients were included, including 160 in the main cohort and 200 in the validation cohort. Time to POD, Ki67 ≥ 30%, and MCL International Prognostic Index (MIPI) were associated with progression-free survival (PFS2) and overall survival (OS2) from the start of 2L BTKis. C-indexes were consistently ≥0.68 in both cohorts. Web/application-based calculators based on nomograms and prognostic indexes to estimate PFS2 and OS2 were constructed. The 2L BTKi MIPI identifies 3 groups with distinct 2-year PFS2, including high risk (14%), intermediate risk (50%), and low risk (64%). Time to POD, Ki67, and MIPI are associated with survival outcomes in patients with R/R MCL receiving 2L BTKis. Simple clinical models incorporating these variables may assist in planning for alternative therapies such as chimeric antigen receptor T-cell therapy, allogeneic stem cell transplantation, or novel agents with alternative mechanisms of action.

As experienced authors, statisticians, editors, and scientists, we present the following comments to highlight some usages or omissions that are common in research manuscripts. Consideration of these comments will improve practices of data analysis and reporting.

Abstract Background: Non-small cell lung cancer (NSCLC) tissue is a valuable resource for diagnosis, treatment planning, and drug development. Current 2D histopathological techniques introduce under-sampling error (i.e., a single 5 um section represents 0.5% of a 1 mm thick biopsy), interobserver variability, and fail to capture the biology contained within the entire tissue sample. We have developed a suite of technologies to stain, chemically clarify, image, visualize, and analyze entire intact NSCLC tissue samples. Methods: Human NSCLC tissue, stored frozen in OCT, was fixed in 4% paraformaldehyde, stained with nuclear (TOPRO-3) and general protein (Eosin) fluorescent dyes, and optically cleared using a modified iDISCO protocol with ethyl cinnamate as the refractive index matching solution. Whole, intact tissue samples, roughly 1-5mm3 in volume, were imaged at 2 microns/pixel resolution with an open-top light-sheet microscope (3Di, Alpenglow Biosciences). Smaller regions of interest (ROIs) with key pathologic features were reimaged at higher resolution, 0.17 microns/pixel, to reveal subnuclear features and for cell typing. Visualization was performed using Aivia software. Results: NSCLC tissue samples were successfully imaged in 3D. Low resolution images (2 microns/pixel) were obtained within 4-31 minutes, depending on the tissue volume. The 3D distribution of cancer cells, immune cells, vessels, and fibrosis varied substantially throughout the volume of the tissue. Recognizable histologic features, including nests of tumor cells surrounded by vasculature and immune cells, were readily visualized. Squamous and adenocarcinoma with its subtypes (solid, acinar, lepidic, and micropapillary) morphologies were recognizable in 2D optical sections of the 3D datasets. Imaging quality degraded in tissue deeper than 1 mm due to light scattering. Conclusion: We assessed intact NSCLC tissue samples measuring up to 5 mm3 using our custom light-sheet microscope and tissue clearing techniques. This novel method enables us to visualize key features of NSCLC such as the tumor interfaces, tertiary lymphoid structures, vessels and fibrosis in the entire tissue sample, preventing under sampling error, and potentially enabling new biologic insights. Next steps include segmentation and quantification of key tissue structures such as tumor volume, immune cell distribution, and fibrosis/immune cell exclusion. This proof-of-concept study provides motivation for further investigation into the significance of 3D tissue features in NSCLC tissue samples. Citation Format: Alexandra Alvarsson, Carl Storey, Brandy Olin Pope, Caleb Stoltzfus, Robert Vierkant, Jessica Tufariello, Aaron Bungum, Julia Naso, Cheuk Ki Chan, Eric Edell, Christopher Hartley, Janani Reisenauer, Nicholas Reder. 3D assessment of the lung cancer microenvironment using multi-resolution open-top light-sheet microscopy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6624.

Abstract Background: The genotoxin colibactin, produced by Escherichia coli containing the pks island, is associated with a tumor single base substitution (SBS) mutational signature SBS88. It is unknown whether lifestyle and environmental factors related to gut dysbiosis impact colorectal cancer (CRC) risk and survival differently by colibactin signature status. Methods: Utilizing the resources of the Genetic Epidemiology of Colorectal cancer Consortium and Colon Cancer Family Registry (GECCO-CCFR), a consortium including both case-control and cohort study designs, SBS88 tumor mutational signature was measured in 4308 CRC cases who were microsatellite stable (MSS) and had at least five somatic single nucleotide variants for signature decomposition. Associations of 13 lifestyle and environmental factors with CRC risk by colibactin signature status were assessed using logistic and multinomial regression; associations with CRC survival were assessed using Cox proportional hazards regression. Results: 392 (9%) of the 4308 MSS tumors were positive for SBS88. Having a BMI ≥30 kg/m2 (versus a BMI 18.5-24.9 kg/m2) was strongly associated with worse CRC-specific survival among those with the SBS88 signature, but not among those with SBS88 negative CRC [further adjusted hazard ratio (HR) = 3.40 95% confidence interval (CI) 1.47, 7.84, and HR = 0.97 95% CI 0.78, 1.21, respectively, P for heterogeneity = 0.066]. Associations of fruit intake with CRC risk may be differential by SBS88 status. In minimally adjusted models, those in the highest quartile of fruit intake (versus the first quartile) had 0.53 (95% CI 0.37, 0.76) times the risk of SBS88 positive CRC, as opposed to 0.75 (95% CI 0.66, 0.85) times the risk of SBS88 negative CRC (P for heterogeneity = 0.047). Among cohort studies specifically, associations between CRC risk and BMI, alcohol, and fruit intake also differed by SBS88 status (P for heterogeneity ranging 0.02-0.05). Conclusions: Higher BMI may be associated with worse CRC-specific survival among those with SBS88 positive tumors. BMI, alcohol, and dietary factors may be differentially associated with CRC risk based on SBS88 status. Citation Format: Claire Elizabeth Thomas, Peter Georgeson, Conghui Qu, Robert S. Steinfelder, Daniel D. Buchanan, Mark A. Jenkins, Andrea Gsur, Jane C. Figueiredo, Polly A. Newcomb, Peter T. Campbell, Christina Newton, Caroline Y. Um, Lisa Boardman, Victor Moreno, Jenny Chang-Claude, Michael Hoffmeister, Marc J. Gunter, Andrew T. Chan, Shuji Ogino, Ellen L. Goode, Brigid Lynch, Yohannes A. Melaku, Steven Gallinger, Sonja I. Berndt, Wen-Yi Huang, Ulrike Peters, Amanda I. Phipps. Lifestyle and environmental factors in relation to colorectal cancer risk and survival by colibactin tumor mutational signature status [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6453.

AbstractBackgroundObtaining a diagnosis and treating pulmonary malignancies during the same anesthesia requires either an on‐site pathologist or a system for remotely evaluating microscopic images. Cytology specimens are challenging to remotely assess given the need to navigate through dispersed and three‐dimensional cell clusters. Remote navigation is possible using robotic telepathology, but data are limited on the ease of use of current systems, particularly for pulmonary cytology.MethodsAir dried modified Wright‐Giemsa stained slides from 26 touch preparations of transbronchial biopsies and 27 smears of endobronchial ultrasound guided fine needle aspirations were scored for ease of adequacy assessment and ease of diagnosis on robotic (rmtConnect Microscope) and non‐robotic telecytology platforms. Diagnostic classifications were compared between glass slides and the robotic and non‐robotic telecytology assessments.ResultsCompared to non‐robotic telecytology, robotic telecytology had a greater ease of adequacy assessment and non‐inferior ease of diagnosis. The median time to diagnosis using robotic telecytology was 85 s (range 28–190 s). Diagnostic categories were concordant for 76% of cases in robotic versus non‐robotic telecytology and 78% of cases in robotic telecytology versus glass slide diagnosis. Weighted Cohen's kappa scores for agreement in these comparisons were 0.84 and 0.72, respectively.ConclusionsUse of a remote‐controlled robotic microscope improved the ease of adequacy assessment compared to non‐robotic telecytology and enabled strongly concordant diagnoses to be expediently rendered. This study provides evidence that modern robotic telecytology is a feasible and user‐friendly method of remotely and potentially intraoperatively rendering adequacy assessments and diagnoses on bronchoscopic cytology specimens.

TPS7587 Background: Covalent (c) Bruton tyrosine kinase inhibitors (BTKi) have transformed the management of MCL, but these agents are not curative. cBTKi share pharmacologic liabilities (e.g., low oral bioavailability, short half-life), which collectively may lead to suboptimal BTK target coverage especially in rapidly proliferating tumors with high BTK protein turnover such as MCL, which can manifest as acquired resistance to BTKi. Pirtobrutinib, a highly selective, non-covalent (reversible) BTKi, has favorable oral pharmacology that enables continuous BTK inhibition throughout the dosing interval regardless of intrinsic rate of BTK turnover. In the phase 1/2 BRUIN study, pirtobrutinib demonstrated promising durable overall response rates and was well tolerated in patients (pts) with MCL regardless of prior therapy (including cBTKi), number of prior lines of therapy, or reason for prior cBTKi discontinuation. Pirtobrutinib was approved by the FDA in January 2023 for R/R MCL after 2 prior lines of therapy including a BTKi. The objective of this study is to establish whether pirtobrutinib is superior to investigator’s choice of cBTKi in pts with previously treated, BTKi naïve MCL. Methods: BRUIN MCL-321 (NCT04662255) is a randomized, open-label, global phase 3 study comparing pirtobrutinib monotherapy versus investigator’s choice of cBTKi monotherapy (ibrutinib, acalabrutinib, or zanubrutinib) in pts with previously treated, BTKi naïve MCL. Approximately 500 pts will be randomized 1:1 and stratified by sMIPI risk (low/intermediate vs high), comparator BTKi (ibrutinib vs acalabrutinib/zanubrutinib), and number of prior lines of therapy (1 vs ≥ 2). Enrollment for this study is ongoing. Adults with a diagnosis of MCL who have received ≥ 1 prior line of systemic therapy for MCL and are BTKi naïve are eligible. Pts must have measurable disease by imaging per Lugano criteria and have progressed on or relapsed following the most recent line of therapy. A history of current or prior CNS involvement, significant cardiovascular disease, stroke or intracranial hemorrhage within 6 months of randomization, and autologous stem cell transplant (SCT), allogeneic SCT or chimeric antigen receptor (CAR) T-cell therapy within 60 days of randomization are key exclusion criteria. Progression-free survival (PFS) per Lugano criteria assessed by an independent review committee is the primary endpoint. Overall response rate, duration of response, investigator-assessed PFS per Lugano criteria, overall survival, event-free survival, time to treatment failure, time to next treatment, PFS2 (time from randomization to disease progression on next line of treatment or death from any cause), safety and tolerability, and pt reported outcomes are secondary endpoints. Clinical trial information: NCT04662255 .

7513 Background: While Bruton tyrosine kinase inhibitors (BTKi) can induce sustained remissions, ongoing response requires continuous treatment and thus long-term safety/tolerability is critical for adherence, maintaining dose intensity, and delivering maximum efficacy. Pirtobrutinib is a highly selective, non-covalent (reversible) BTKi approved by the FDA in January 2023 for R/R mantle cell lymphoma after 2 prior lines of therapy including a BTKi. Pirtobrutinib has demonstrated promising efficacy with low discontinuation and dose reduction rates in patients (pts) with multiple subtypes of R/R B-cell malignancies. However, the long-term safety and tolerability of pirtobrutinib has not yet been reported. Here we report the clinical safety in pts with long-term (≥12 months) pirtobrutinib treatment from the phase 1/2 BRUIN trial. Methods: Pts with R/R B-cell malignancies who received ≥12 months of pirtobrutinib were included. Median time to onset, dose reduction, discontinuation, and cumulative incidence rates were determined for treatment emergent adverse event (TEAE) that occurred in ≥20% of pts and select AE of interest associated with BTKi. Results: As of 29 July 2022, 773 pts were enrolled, and 326 (42%) pts received treatment for ≥12 months. Among these 326 pts, median time on treatment was 19 months (IQR: 16,25), with 231 (71%) remaining on pirtobrutinib. The most common TEAE (all grade, regardless of attribution) in this long-term 326 pt cohort were fatigue (32%), diarrhea (31%), Covid-19 (29%), contusion (26%), cough (25%), and back pain (21%). TEAE leading to dose reduction or discontinuation occurred in 23 (7%) and 11 (3%) pts, respectively. Four (1%) pts discontinued due to a treatment-related AE, and 1 pt had a fatal treatment-related AE (Covid-19 pneumonia). Select AE of interest for the long-term pts are shown in the Table. Comprehensive safety analyses describing the frequency of TEAE over time will be presented. Conclusions: Prolonged pirtobrutinib therapy continues to demonstrate a safety profile amenable to long-term administration at the recommended dose without evidence of new or worsening toxicity signals. The safety and tolerability observed in pts on therapy for ≥12 months was similar to previously published safety analyses on all pts enrolled regardless of follow-up. Clinical trial information: NCT03740529 . [Table: see text]

5021 Background: Somatic mutations in hematopoietic progenitor cells accumulate with age leading to clonal expansion in a process called clonal hematopoiesis (CH). CH increases the risk of developing myeloid neoplasms and shortens overall survival (OS), primarily linked to increased cardiovascular (CV) mortality. The impact of CH in metastatic solid cancers has been conflicting, with shorter OS in a broad cancer cohort but prolonged OS in metastatic colorectal cancer, which may be influenced by prior cytotoxic therapy that can promote emergence of CH. As AR pathway inhibitors (ARPIs) are associated with CV adverse events (AE), exploring the impact of CH in patients (pts) with mCRPC is of interest. Methods: A 9 gene targeted DNA sequencing panel designed to capture common CH mutations ( DNMT3A, TET2, ASXL1, PPM1D, TP53, CHEK2, SRSF2, SF3B1, JAK2) was applied to pre-treatment peripheral blood samples of 957 pts enrolled in the Alliance A031201 phase 3 trial of enzalutamide versus enzalutamide plus abiraterone/prednisone in the first line mCRPC setting. No difference in OS was found between treatment arms. The primary endpoint was the impact of CH on OS; secondary and exploratory endpoints included progression-free survival (PFS) and associations with baseline comorbidities and AEs (hematologic and CV). Cox proportional-hazards and logit models were adjusted for treatment arm, age, and radiation therapy (RT). Results: CH was common with 57% of pts having low CH (VAF>0.5% in 1+ mutation, L-CH), 24% having standard CH (VAF>2%, CH), and 7% having high CH (VAF>10%, H-CH). 4% of pts had 2+ CH mutations and 1% had 3+ mutations. Patients with CH were older (73.1 vs 70.2) and had higher rates of prior RT (58.4% vs 55.7%) and prior chemotherapy (3.9% vs 2.2%). No differences in OS were detected in pts with L-CH, CH, or H-CH. Similarly, no differences in PFS or baseline CV comorbidities were seen in any CH group. Pts with H-CH and TET2-mutated CH had statistically higher odds of any CV event (adjusted p=0.0004 and p=0.010, respectively) There was also a difference in the occurrence of major adverse CV events (MACE) by H-CH status (5.8% vs. 1.9%, adjusted p=0.042), while there was no difference seen for CH (3.4% vs 1.8%, adjusted p=0.147). Regarding hematologic AEs, one pt with a TP53 mutation (VAF 0.94%) developed myelodysplastic syndrome. Conclusions: CH did not affect OS or PFS in pts with mCRPC treated with ARPIs in the A031201 trial. However, CH with VAF>10% and TET2-mutated CH were associated with an increased rate of all CV AEs, suggesting an additive effect of ARPI therapy and CH on adverse CV outcomes. Confirmatory studies are warranted to assess whether CH should be considered in the risk-benefit discussion for pts receiving ARPIs.