Translational Endpoints Research Articles

CTNI-15. A PERIOPERATIVE STUDY OF SAFUSIDENIB IN PATIENTS WITH IDH1 MUTATED GLIOMA

Abstract BACKGROUND IDH mutations cause aberrant accumulation of (R)-2-hydroxyglutarate (2-HG), an oncometabolite that promotes tumorigenesis through abnormal hypermethylation of histones and DNA as well as suppression of normal cellular differentiation. IDH inhibition significantly improves progression free survival in patients with IDH mutant WHO grade 2 glioma, however most patients progress, and there is a lack of understanding on mechanistic reasons for failure. METHODS We tested Safusidenib, an oral, blood brain barrier penetrant IDH1 R132X enzyme inhibitor in a single arm, open label perioperative study. Patients with IDH1 mutated glioma, treatment naïve to radiation or chemotherapy, received Safusidenib (250 mg BID) for four weeks following surgical biopsy and prior to definitive resection (Part A). After resection patients continued Safusidenib until toxicity or progression (Part B). Translational endpoints include paired whole genome transcriptome sequencing (WGTS), single nuclei RNA sequencing (snRNAseq), spatial transcriptomics and spatial metabolomics as well as longitudinal sampling of blood and CSF for circulating tumour DNA (ctDNA). Here we are reporting Part A of the study. RESULTS As of May/27/2024 10 patients (mean age 37, 40% female) have been enrolled: seven with astrocytoma, three with oligodendroglioma; six had prior surgical resection. Pharmacokinetic sampling showed a mean tumor concentration 2457 ng/mL (range 957.0 – 4810) with tumor:plasma ratio 0.33. Consistent with mechanism, tumor 2-HG reduced 86% from biopsy (mean 75.0μM, range 7.8-203) to surgery (10.3μM, range 2.3 – 30.8), as well as identification of novel biomarkers of response. Paired tumour snRNAseq reveals transcriptional shift with changing cell-to-cell communication, and increased immune infiltration post-treatment, validated by spatial transcriptomics. Additionally, we find reduced heterogeneity consistent with a more differentiated tumour state. Treatment was well tolerated with ongoing follow-up. CONCLUSIONS This innovative trial facilitates intra-patient comparisons and confirmation of the on-target effects of Safusidenib, enhancing understanding of the mechanisms of response and resistance. The approach serves as a proof of concept for advancing drug development in glioma through perioperative trials.

A randomized phase III trial of stereotactic ablative radiotherapy for patients with up to 10 oligometastases and a synchronous primary tumor (SABR-SYNC): study protocol

BackgroundEmerging randomized data, mostly from phase II trials, have suggested that patients with oligometastatic cancers may benefit from ablative treatments such as stereotactic ablative radiotherapy (SABR). However, phase III data testing this paradigm are lacking, and many studies have examined SABR in the setting of metachronous oligometastatic disease. The goal of the SABR-SYNC trial is to assess the effect of SABR in patients with oligometastatic cancers and a synchronous primary tumor.MethodsOne hundred and eighty patients will be randomized in a 1:2 ratio between standard of care (SOC) palliative-intent treatments vs. SOC + ablative therapy (SABR preferred) to all sites of known disease. Randomization will be stratified based on histology and number of metastases at enrollment. SABR may be delivered in 1-, 3- and 5-fraction regimens, with recommended doses of 20 Gy, 30 Gy, and 35 Gy, respectively. Non-SABR local modalities (e.g. surgery, thermal ablation, conventional radiation) may be used for treatment of the primary or metastases at the discretion of the treating physicians, if those modalities are clinically preferred. The primary endpoint is overall survival, and secondary endpoints include progression-free survival, time to development of new metastatic lesions, time to initiation of next systemic therapy, quality of life, and toxicity. Translational endpoints include assessment of circulating tumor DNA and immunological predictors of outcomes.DiscussionSABR-SYNC will provide phase III data to assess the impact of SABR on overall survival in a population of patients with synchronous oligometastases. The translational component will attempt to identify novel prognostic and predictive biomarkers to aid in clinical decision making.Trial registrationClinicaltrials.gov NCT05717166 (registration date: Feb. 8, 2023).

NEOPRISM-CRC: Neoadjuvant pembrolizumab stratified to tumour mutation burden for high risk stage 2 or stage 3 deficient-MMR/MSI-high colorectal cancer.

LBA3504 Background: The prognostic advantage of early stage deficient-MMR/MSI-High colorectal cancer (CRC) is lost after relapse. Hence, there is a clinical imperative to maximise the chance of cure in early-stage disease. Tumour mutation burden (TMB) is an emerging biomarker for response and clinical benefit to immunotherapy in the advanced setting. NEOPRISM-CRC (Neoadjuvant PembRolizumab In Stratified Medicine – ColoReCtal) is the first multicentre Phase II Trial to determine if neoadjuvant pembrolizumab is efficacious and safe, prospectively stratified to TMB. Methods: The trial population included patients (pts) with operable high-risk stage 2 or stage 3 dMMR/MSI-High CRC. Pts with tumours that were TMB high or medium (≥6 mutations/Mb on FoundationOneCDx test) received 3 cycles of pembrolizumab (200mg every 3 weeks) and underwent surgery within 4-6 weeks of last cycle. Pts with TMB low tumours (≤5 mutations/Mb) underwent surgery 4-6 weeks after 1 cycle of pembrolizumab. The primary end point was pathological complete response rate (pCR). Secondary endpoints included 3-year relapse free survival, overall survival, safety, and health-related quality of life. The trial also incorporated translational endpoints to explore relationships between possible predictive novel biomarkers and response to pembrolizumab in blood, tumour tissue and microbiome. We required 19 pts with TMB high or medium tumours to detect a pCR after 3 cycles of neoadjuvant pembrolizumab of 33% (minimum of 10%), with one-sided 5% significance level and 80% power (A’Hern single stage). The trial would be considered a success if ³5/19 of those pts achieved pCR. To achieve this number, we aimed to recruit 32 patients in total. Results: The trial opened on 20th July 2022 and 32 pts were rapidly enrolled. The pCR primary endpoint analysis was performed on 1st March 2024. The primary endpoint was exceeded with the pCR in the intent to treat pts (N=32) as well as the pCR in evaluable tumours shown in Table 1. Median TMB was 42 mutations/Mb (4-82). There was only 1 TMB low tumour and no TMB medium tumours. In the TMB high-medium cohort there were 32 evaluable resected tumours as 1 pt had 3 synchronous primaries, and 1 pt did not undergo surgery due to toxicity as well as pt choice. There were no immune-related toxicities >Grade 3. At a median follow-up of 6 months (range 2-15), no pts have had disease recurrence. Conclusions: Neoadjuvant pembrolizumab for early stage deficient-MMR/MSI-High CRC is highly efficacious and safe. Longer follow up is needed to assess relapse free survival and translational biomarker work is ongoing. Clinical trial information: NCT05197322 . [Table: see text]

Phase I/II trial of healthy donor fecal microbiota transplant (hdFMT) in PD-1 relapsed/refractory (R/R) non-small cell lung cancer (NSCLC).

TPS8648 Background: A significant portion of patients (pts) with advanced NSCLC either do not respond or become refractory to immune checkpoint inhibitor (ICI) therapy administered alone or in combination with platinum chemotherapy. In addition to tumor-intrinsic mechanisms supporting resistance to anti-PD-1, the gut microbiome is a major tumor-extrinsic regulator of responses to anti-PD-1. In mice, gut microbiota modulate therapeutic activity of anti-PD-1 ICI, and administration of gut commensals or responder-derived fecal microbiota transplantation (R-FMT) promotes anti-PD-1 efficacy. Longitudinal analyses of gut microbiome samples from ICI-treated cancer pts suggests key bacterial species are associated with favorable response, although limited concordance among the identified species has been reported across studies. We and others have previously demonstrated that microbiome modulation reversed anti-PD-1 resistance in anti-PD-1 R/R melanoma, and augmented benefit of anti-PD-1 monotherapy in ICI-naïve melanoma. We hypothesize that intestinal dysbiosis mediates anti-PD-1 resistance in anti-PD-1 R/R NSCLC, and that hdFMT may resensitize NSCLC to PD-1 blockade. Methods: This is an investigator-initiated, phase II trial of hdFMT with pembrolizumab (P) in pts with R/R NSCLC progressed on prior anti-PD-1 based therapy alone or in combination with platinum chemotherapy. Pts must have measurable disease per RECIST v1.1, no untreated CNS metastases, and no contraindications to FMT administration. hdFMT is derived from non-obese, healthy, adults aged ≥18 to <70, with no chronic diseases, and no recent antibiotic exposure. Donors are screened broadly for transmissible agents including SARS-CoV-2 using bookend screening. hdFMT is processed to make fecal infusates and orally bioavailable capsules. Eligible pts receive P 200mg every 3 weeks (Q3W). hdFMT is administered endoscopically on D1, and D42, and thereafter via capsules until progression or unacceptable toxicity. Response is assessed at D73, and thereafter Q12W. Pts undergo tumor biopsies at baseline and at W8, with optional post-progression biopsy. Primary endpoint: overall response rate (ORR) assessed using RECIST v1.1 by Blinded Independent Central Review (BICR). Secondary endpoints include: safety, progression-free survival (PFS), overall survival (OS), and landmark PFS/OS. Key translational endpoints include immune activation (tumor tissue, blood), metagenomic engraftment, and transcriptomic analyses of intestinal luminal myeloid cells and exfoliome. The null hypothesis that the true ORR is 5% will be tested versus a 1-sided alternative hypothesis of ≥25%, using Simon’s minimax two-stage design (type I error 0.04, power 0.9, when true response rate is 0.25). PFS and OS will be estimated via Kaplan-Meier method. Enrollment has commenced. Clinical trial information: NCT05669846 .

Randomized phase II trial of pembrolizumab/lenvatinib (P+L) +/- responder fecal microbiota transplant (R-FMT) in PD-1 relapsed/refractory (R/R) cutaneous melanoma (MEL).

TPS9607 Background: A significant portion of patients (pts) with advanced MEL develop resistance to immune checkpoint inhibitors (ICI). The gut microbiome is a major tumor-extrinsic regulator of ICI response. In mice, gut microbiota modulate therapeutic activity of ICI, and administration of certain gut commensals or responder-derived fecal microbiota transplantation (R-FMT) promotes anti-PD-1 efficacy in melanoma-bearing mice. In the LEAP-004 trial, P+L produced 21% ORR in PD-1 R/R MEL with Gr3+ TRAE 45.6%. Longitudinal analyses of gut microbiome samples from ICI-treated cancer pts suggests key species including Actinobacteria and Firmicutes are associated with favorable response. We and others have previously demonstrated that microbiome modulation using R-FMT reversed PD-1 non-response in PD-1 R/R MEL. In PD-1 naïve MEL, healthy donor FMT (hdFMT) augments benefit of PD-1 monotherapy. We hypothesized that intestinal dysbiosis mediates PD-1 resistance in PD-1 R/R MEL, microbiome modulation may reverse TKI toxicity, and that R-FMT may resensitize MEL to PD-1 blockade. Methods: This is an investigator-initiated, randomized, phase II trial of P+L vs. P+L+R-FMT in PD-1 R/R MEL. Pts must have measurable disease per RECIST v1.1, no active CNS metastases (or if present, previously treated and stable on repeat imaging), and no contraindications to FMT administration. R-FMT is derived from non-obese, advanced MEL with durable response (mPFS ≥24 months) following prior PD-1 ICI, with no recent (≤1 month) antibiotic exposure. Donors are screened broadly for infectious agents including SARS-CoV-2 using bookend screening. R-FMT is processed to make fecal infusates and orally bioavailable capsules. Eligible pts are randomized 1:1 to either P+L [P 200mg every 3 weeks (Q3W) along with L 20mg orally once daily] or P+L+R-FMT. R-FMT is administered endoscopically on D1, and D42, and thereafter via capsules until progression or unacceptable toxicity. Response is assessed at D73, and thereafter Q12W. Pts undergo biopsies at baseline and W8, with optional biopsy at progression. Primary endpoint: ORR assessed using RECIST v1.1 by Blinded Independent Central Review (BICR). Secondary endpoints include: safety, progression-free survival (PFS), overall survival (OS), and landmark PFS/OS. Key translational endpoints include immune activation (tumor tissue, blood), metagenomic engraftment, and transcriptomic analyses of intestinal luminal myeloid cells and exfoliome. The null hypothesis that the true ORR is 20% will be tested versus a one-sided alternative hypothesis of ≥50%. This design has a type I error rate 0.10 and power 0.8 when the true response rate is 0.25. Enrollment has commenced. Clinical trial information: NCT06030037 .

Ovarian Cancer Clinical Trial Translational Endpoints Research Award (DOD)

Ovarian Cancer Clinical Trial Translational Endpoints Research Award (DOD)

Abstract CT030: Randomized placebo-controlled, biomarker-stratified phase 1b microbiome modulation trial for metastatic melanoma demonstrates impact of antibiotic pre-conditioning regimen on the microbiome and immunity

Abstract Background: Gut microbiota modulation shows promise in improving immune checkpoint blockade (ICB) response; however, precision biomarker-driven trials using rationally-designed consortia are lacking. To address this, we performed a multi-center, randomized placebo-controlled, biomarker-stratified phase 1 trial in patients with ICB-naïve unresectable or metastatic melanoma using SER-401, a bacterial consortia enriched for Firmicutes spores and Ruminococcaceae. Methods: MCGRAW was a multi-center, randomized, blinded, and placebo-controlled phase 1b study in patients with advanced melanoma. Patients were randomized 2:1 to the SER-401 active or placebo arm, respectively, and stratified by baseline stool Ruminococcaceae abundance. Patients received an oral vancomycin (vanco) preparative regimen+SER-401 (vanco+SER-401 arm), versus placebo antibiotic+placebo (Placebo arm), followed by nivolumab. Stool, blood and tumor samples were collected at baseline and on treatment. The primary endpoint was safety, with additional secondary endpoints (SER-401 microbiome engraftment, overall response rate (ORR), disease control rate (DCR), and other translational endpoints). The study was not powered for comparison between arms. Results: 14 patients were randomized (n=8 vanco+SER-401, n=6 placebo). In the vanco+SER-401 arm, ORR was 25.0% and DCR was 37.5%, with no Grade 3-4 treatment-related adverse events (TRAE); in the placebo arm, ORR was 66.7% and DCR was 83.3%, with 1 (17%) TRAE. Notably, pre-conditioning with vanco was associated with significant shift in the microbiome taxonomic composition, with depletion of target families such as Ruminococcaceae (p=0.008, Wilcoxon signed-rank test), and other spore-formers, followed by their recovery post dosing with SER-401. There was a significant increase in multiple ICB-resistance associated pathways (e.g. butyrate synthesis, p<0.0001), and a decrease in response-associated pathways after vanco preconditioning; these changes did normalize by nivolumab initiation. There was corresponding increase in systemic proteomic markers of inflammation after vanco, which also normalized by first dose of immunotherapy. Conclusions: This first-of-its-kind, placebo-controlled, randomized biomarker-driven microbiome modulation trial demonstrated that SER-401 and anti-PD1 are a safe combination in melanoma patients. The study was limited by poor accrual during the COVID-19 pandemic. Nonetheless, important insights were gained via translational analyses, suggesting that antibiotic preconditioning and interventional drug dosing regimens should be carefully considered when designing such trials. Additional placebo-controlled biomarker-driven microbiome trials are needed in this age of precision medicine. Trial registration: ClinicalTrials.gov (NCT03817125) Citation Format: Isabella C. Glitza Oliva, Yongwoo David Seo, Christine N. Spencer, Jennifer R. Wortman, Elizabeth M. Burton, Farah A. Alayli, Christopher Loo, Shikha Gautam, Ashish V. Damania, Julie Densmore, Justin Fairchild, Christopher Cabanski, Matthew C. Wong, Christine B. Peterson, Brian Weiner, Nathan Hicks, John Aunins, Christopher McChalicher, Michael T. Tetzlaff, Omid Hamid, Patrick A. Ott, Genevieve M. Boland, Ryan J. Sullivan, Kenneth F. Grossmann, Nadim J. Ajami, Theresa M. LaVallee, Matthew R. Henn, Hussein A. Tawbi, Jennifer A. Wargo. Randomized placebo-controlled, biomarker-stratified phase 1b microbiome modulation trial for metastatic melanoma demonstrates impact of antibiotic pre-conditioning regimen on the microbiome and immunity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT030.

NABNEC: A randomised phase II study of nab -paclitaxel in combination with carboplatin as first line treatment of gastrointestinal neuroendocrine carcinomas (GI-NECs).

589 Background: Neuroendocrine carcinomas (NEC) are rare and aggressive cancers. There are no randomised trials to date to establish standard therapy for advanced G3 gastrointestinal (GI) NENs. Extrapolating from small cell lung cancer data, standard practice is to treat G3 GI-NENs with etoposide and carboplatin. Paclitaxel is also active in NECs however there is no data on the role of nab -paclitaxel. NABNEC (ANZCTR # 12616000958482) aimed to determine the activity, safety and tolerability of carboplatin and nab -paclitaxel in advanced G3 GI-NENs and to enhance our understanding of the biology and imaging characteristics of such NENs. Methods: NABNEC was designed as a randomised non-comparative phase II study, evaluating the activity of nab- paclitaxel in patients with advanced and/or metastatic non-resectable G3 GI-NENs. The statistical plan was that 46 evaluable patients in the experimental arm would give 80% power and 95% confidence to rule out a 30% RR in favour of a more interesting RR of 50% at 6 months. Protocol version 3.0 was amended and randomisation to the control arm was suspended after 12 patients. Primary endpoint was objective response rate (RR) by RECIST 1.1. Secondary endpoints were progression free survival, overall survival, adverse events by NCI-CTCAE V4.03 and quality of life (EORTC QLQC30, QLQ-GINET21 questionnaires). Translational research endpoints include blood and tissue biomarkers including circulating tumour cells profiling, mutation profile (whole exome sequencing) and DNA methylation profile correlated with clinical endpoints. Correlation of 18-fluoro-deoxyglucose positron emission tomography (FDG-PET) to early response has also been evaluated. Results: 60 patients were accrued between Sep 2016 and Dec 2021 from 16 centres, resulting in 58 evaluable patients, 12 (control arm), 46 (experimental arm). 43 patients (75%) had tumours with Ki-67>55%; the remainder had Ki-67 between 20 and 55%. About 20% had pancreatic primaries; more than half had liver metastases. The NABNEC trial met its primary endpoint. RR was 53% (38-69%) in the experimental treatment arm compared to 42% (16-71%) in the control group. Progression free survival was not different between the 2 treatments. 24m overall survival was 25% in the experimental group compared to 17% in the control. Grade 3 toxicity was worse in the nab-paclitaxel arms (52% v 42%). Quality of life and tertiary outcomes are being analysed. Conclusions: The combination of carboplatin and nab-paclitaxel is an active regimen for G3 GI-NENs. Further evaluation in a Phase III study is warranted. Clinical trial information: ACTRN12616000958482.

Transcending the challenge of evolving resistance mechanisms in Pseudomonas aeruginosa through β-lactam-enhancer-mechanism-based cefepime/zidebactam.

Compared to other genera of Gram-negative pathogens, Pseudomonas is adept in acquiring complex non-enzymatic and enzymatic resistance mechanisms thus remaining a challenge to even novel antibiotics including recently developed β-lactam and β-lactamase inhibitor combinations. This study shows that the novel β-lactam enhancer approach enables cefepime/zidebactam to overcome both non-enzymatic and enzymatic resistance mechanisms associated with a challenging panel of P. aeruginosa. This study highlights that the β-lactam enhancer mechanism is a promising alternative to the conventional β-lactam/β-lactamase inhibitor approach in combating ever-evolving MDR P. aeruginosa.

ARTIA-Bladder: Daily Online Adaptive Short-Course Radiation Therapy (RT) and Concurrent Chemotherapy for Muscle-Invasive Bladder Cancer (MIBC): A Prospective Trial of an Individualized Approach for Reducing Bowel and Bladder Toxicity

Concurrent chemo-radiotherapy is commonly prescribed for muscle-invasive bladder cancer (MIBC). Post hoc analysis of two large, randomized trials found that hypofractionation improves loco-regional control (LRC) vs. standard fractionation in this population. A challenge in traditional image-guided radiotherapy of the bladder is that daily changes in bladder position and size requires large margins to ensure target coverage. This makes it difficult to spare uninvolved bladder from high-dose treatment, increases the risk of bowel toxicity, and results in historical rates of acute G3+ toxicity exceeding 20-30%. Daily online adaptive RT (ART) may enable reduced, personalized margins that maintain target coverage while reducing dose to OARs. This prospective clinical trial will test whether: 1) participants undergoing ART for MIBC have a lower rate of acute G3+ GI/GU toxicity compared with the 31% historical control rate (Stage III BC2001 trial), and 2) 2-year LRC with ART will be non-inferior to historical controls (75%). This multi-national trial will enroll 165 adult subjects with stage cT2-T4aN0M0 urothelial MIBC. Subjects will have undergone an attempt at maximal transurethral resection of bladder tumor. Patients with clinically involved nodes or G2+ GI or G3+ GU symptoms/conditions at baseline are ineligible. Concurrent with chemotherapy, participants will receive (at the discretion of the investigator) either 55 Gy in 20 fx to whole-bladder or 46 Gy in 20 fx to whole-bladder plus simultaneous in-field boost of 55 Gy in 20 fx to tumor bed. A personalized ITV will be derived for each subject based on bladder expansion, as assessed on two CT simulations separated by 30 min. Daily ART will be attempted for all subjects. The primary endpoint is acute G3+ GI/GU toxicity. Secondary endpoints are LRC; quality of life (EORTC QLQ-BLM30, EPIC 26 bowel and urinary); global function (EQ-5D-5L ); 2-year disease-free, bladder intact event-free, and overall survival; 2-year bladder cancer-specific mortality; NTCP model of acute GI toxicity for hypofractionated bladder RT; workflow feasibility of ART; improved target coverage ± reduced dose to critical OARs vs. non-ART dosimetry; acute G3+ GI/GU toxicity rate in subjects with ≥75% of their treatments as ART; and acute G3+ GI/GU toxicity in the cohort treated with partial bladder boost. Exploratory translational and correlative endpoints will also be examined. This trial opened to enrollment on Feb 2, 2023; the study duration is expected to be 4-5 years. This prospective clinical trial will provide robust clinical data to inform healthcare providers' decisions on the use of daily online ART and hypofractionation as a bladder preservation strategy for this population.

Exploring the utility of liquid biopsy (ctDNA) as a translational endpoint in clinical trials for endometrial cancer (012)

Exploring the utility of liquid biopsy (ctDNA) as a translational endpoint in clinical trials for endometrial cancer (012)

A phase 2 study of dasatinib in recurrent clear cell carcinoma of the ovary, fallopian tube, peritoneum or endometrium: NRG oncology/gynecologic oncology group study 0283

ObjectiveGynecologic cancers are traditionally managed according to their presumed site of origin, without regard to the underlying histologic subtype. Clear cell histology is associated with chemotherapy refractoriness and poor survival. Mutations in SWI/SNF chromatin remodeling complex member ARID1A, which encodes for BAF250a protein, are common in clear cell and endometriosis-associated endometrioid carcinomas. High-throughput cell-based drug screening predicted activity of dasatinib, a tyrosine kinase inhibitor, in ARID1A-mutant clear cell carcinoma. MethodsWe conducted a phase 2 clinical trial of dasatinib 140 mg once daily by mouth in patients with recurrent or persistent ovarian and endometrial clear cell carcinoma. Patients with measurable disease were enrolled and then assigned to biomarker-defined populations based on BAF250a immunohistochemistry. The translational endpoints included broad next-generation sequencing to assess concordance of protein expression and treatment outcomes. ResultsTwenty-eight patients, 15 of whom had tumors with retained BAF250a and 13 with loss of BAF250a were evaluable for treatment response and safety. The most common grade 3 adverse events were anemia, fatigue, dyspnea, hyponatremia, pleural effusion, and vomiting. One patient had a partial response, eight (28%) had stable disease, and 15 (53.6%) had disease progression. Twenty-three patients had next-generation sequencing results; 13 had a pathogenic ARID1A alteration. PIK3CA mutations were more prevalent in ARID1A-mutant tumors, while TP53 mutations were more prevalent in ARID1A wild-type tumors. ConclusionsDasatinib was not an effective single-agent treatment for recurrent or persistent ovarian and endometrial clear cell carcinoma. Studies are urgently needed for this rare gynecologic subtype.

Clinical applications of circulating tumor DNA in indolent B-cell lymphomas

Indolent B-cell lymphomas are generally incurable with standard therapy and most patients have a prolonged disease course that includes multiple treatments and periods of time in which they do not require therapy. Currently available tools to monitor disease burden and define response to treatment rely heavily on imaging scans that lack tumor specificity are unable to detect disease at the molecular level. Circulating tumor DNA (ctDNA) is a versatile and promising biomarker being developed across multiple lymphoma subtypes. Advantages of ctDNA include high tumor specificity and limits of detection that are significantly lower than imaging scans. Potential clinical applications of ctDNA in indolent B-cell lymphomas include baseline prognostication, early signs of treatment resistance, measurements of minimal residual disease, and a noninvasive method to directly monitor disease burden and clonal evolution after therapy. Clinical applications of ctDNA have not yet proven clinical utility but are increasingly used as translational endpoints in clinical trials testing novel approaches and the analytic techniques used for ctDNA continue to evolve. Advances in therapy for indolent B-cell lymphomas include novel targeted agents and combinations that achieve very high rates complete response which amplifies the need to improve our current methods to monitor disease.

Development of a novel immune-related toxicity grading system for predicting outcomes in patients with solid tumours treated with immune checkpoint inhibitors (ICI).

2644 Background: Adoption of ICI in clinical practise has led to improved outcomes in many tumour types. Their use is associated with immune related adverse events (irAEs), with unpredictable onset targeting multiple organs and for which conventional CTCAE toxicity grading has significant limitations. In addition, the correlation of irAEs to efficacy of ICI is becoming increasingly recognised. Here we present a novel toxicity assessment tool and describe its relationship with cancer outcomes. Methods: Data were collected from the Pathobiology of Adverse Immune Reactions (PAIR) prospective cohort study at Guy’s Hospital from February 2018 until end of May 2022. Solid tumour patients with advanced disease naïve to ICI who received at least 1 dose were included. Minimum 6 months of follow-up was required. IrAEs were captured based on the OST score which evaluates the number of affected Organs (O), number of Severe CTCAE (³G3) toxicities (S) and sum of all grade Toxicities (T). OST was calculated at death or end of follow-up. Patients were divided in high and low toxicity groups, defined by the median value for each parameter. Descriptive statistics and crude and multivariate survival Cox Proportional Hazards regression analyses were performed accounting for age, tumour type and treatment. Results: A total of 123 patients were included. Median age was 68 years (range 23-87 yrs); 67 (54%) were male; 104 (85%) were White Caucasian. Most common tumour types were melanoma (33%), non-small cell lung (24%) and renal cell carcinoma (22%). Forty-six patients (37%) received Ipilimumab-Nivolumab, 37 (30%) Pembrolizumab and 24 (20%) Nivolumab. Twenty-two (18%) had autoimmune disease at baseline. Hypothyroidism (6%) and psoriasis (2%) were most common. Median number of affected organs was 2 (range 0-7), 32 (26%) had ≥1 G3 toxicity and the median T score was 3 (range 0-15). Survival data were available for 120 patients. After median follow-up of 39 months, 66 deaths (53.7%) occurred. Median OS was 16.9 months (95% C.I 9.9-24.1). High toxicity groups presented reduced risk of death compared to low-toxicity groups when evaluated for individual OST parameters [HR for Organ tox group (95% CI): 0.359 (0.198-0.649), HR for Severity group (95% CI): 0.402 (0.200-0.808), HR for Toxicity score group (95% CI): 0.353 (0.190-0.657)]. Of the three parameters, the number of Organs (O) was most strongly associated with reduced risk of death when analysed as a continuous variable [HR (95% CI): 0.683 (0.577-0.808)]. Conclusions: We have developed a novel immune toxicity grading system which can potentially predict survival outcomes for patients treated with ICI. Further prospective evaluation and correlation to translational secondary endpoints with immunological phenotyping is ongoing. External validation is warranted to support further use of OST in routine clinical practice.

Neoadjuvant immunotherapy with ipilimumab plus nivolumab and radiologically and pathologically quantifiable responses through modulation of the tumour microenvironment in resectable hepatocellular carcinoma.

4129 Background: Liver resection (LR) is a potentially curative option for early-stage hepatocellular carcinoma (HCC), and immune checkpoint inhibitors (ICI) are being investigated in the perioperatory setting to improve long-term relapse rates and survival outcomes. Methods: PRIME‐HCC is a phase Ib study testing nivolumab (3 mg/kg, day 1 and day 22) plus ipilimumab (1mg/kg, day 1 only) (N+I) prior to LR in resectable HCC. Primary endpoint was safety, while secondary endpoints included radiological response (per RECIST v1.1) and pathological response on resection specimens (ReS). Translational endpoints encompassed analysis of tissue samples with multiplex immunohistochemistry (MIHC) and gut microbiota profiling with high-throughput sequencing and their correlation with response. Results: As of 7th of February 2023, 25 patients (pts) were enrolled, all Child-Pugh A, mostly male (n=18, 72%), with cirrhosis (n=13, 52%), and viral hepatitis (44%, 4 HBV and 7 HCV). Any-grade adverse events (AEs) occurred in 88% pts (n=22), of which 24% (n=6) grade (G) 3. No G4-5 AEs were recorded. Any-grade treatment-related (tr)AEs were reported by 72% pts (n=18), including 8% G3 trAEs (n=1 ALT/AST elevation and n=1 dyspnea). After a median follow-up of 14.5 months (95% CI 7.0-22.0), 21 pts were assessed for radiological response and underwent surgery. Median time from treatment start to LR was 2.4 months (interquartile range 2.2-2.7). LR was delayed in 1 pt (4.8%) because of G2 tr-hypothyroidism but occurred uneventfully. Objective response rate was 29% (n=5 partial responses, n=1 complete response [CR]); disease control rate was 95% (n=20), with 1 progressor having a mixed HCC/cholangiocarcinoma. Major pathological response (MPR), defined as ≥70% tumour regression, was observed in 56% (n=9) of the pathologically evaluable ReS (n=16), with 38% pathological CR (n=6). In the MIHC analyses, pretreatment biopsies of MPR pts were significantly enriched in peritumoral CD4+ and CD8+ cells, with no intratumoral difference. When comparing baseline biopsies and ReS, MPR pts had a significant decrease of intratumoral FOXP3+/CD4+ regulatory T cells (Tregs), while peritumoral Tregs increased significantly in non-MPR ReS. In baseline stool samples, α and β diversity did not differ across responders (R) and non-responders (NR), nor it changed after ICI. However, pre-treatment stool samples of NR pts were significantly enriched in Alistipes and Colinsella genera. Conclusions: Neoadjuvant N+I is feasible and tolerable for early-stage HCC, with promising radiological and pathological response rates. Study of tissue and gut microbiota highlights tumor and host-related changes. Immune infiltrate and gut microbiota composition lend themselves as predictors of anti-tumour efficacy of N+I combination. Clinical trial information: NCT03682276 .

Chemoradiotherapy with concurrent durvalumab for the palliative treatment of oligometastatic esophageal and gastroesophageal carcinoma with dysphagia: A single arm phase 2 clinical trial, PALEO.

TPS4172 Background: Many patients diagnosed with esophageal cancer have dysphagia from their primary tumor and de novo metastatic disease. While multiple therapies are available, there is no accepted standard or sequence of therapies to both relieve dysphagia and control distant disease. Our preceding Phase I clinical trial showed that a 2 week hypofractionated chemoradiotherapy (CRT) protocol (30Gy/10# with concurrent weekly carboplatin and paclitaxel) is well tolerated and provides rapid dysphagia relief. Immune checkpoint inhibition has activity in esophageal and gastroesophageal (GEJ) cancer and concurrent radiotherapy may improve T cell priming through tumor antigen release. In PALEO, patients begin durvalumab concurrent with primary tumor CRT, and receive stereotactic body radiotherapy (SBRT) (24Gy/3#) to a single metastasis to maximize the breadth of tumor antigen exposure. Tissue and blood-based studies are planned to identify biomarkers for response, including immunosequencing to test for post-radiotherapy expansion in T cell receptor diversity. Methods: Eligible patients have biopsy-proven esophageal or GEJ cancer, either squamous cell or adenocarcinoma histology, with oligometastatic (1-5 metastases on FDG-PET scan outside the primary tumor radiotherapy field) or locoregionally advanced disease unsuitable for surgery, dysphagia (Mellow score >0), and ECOG PS 0-2. Key exclusion criteria are prior treatment, tumor HER2 positivity, prior thoracic radiotherapy, tracheo-esophageal fistula, esophageal stent in situ and contraindications to immunotherapy. Patients begin durvalumab 1500mg q4w with CRT to the primary tumour (30Gy/10# with weekly carboplatin AUC2 and paclitaxel 50mg/m2), and continuing to disease progression, unacceptable toxicity or 2 years. SBRT to one metastasis (24Gy/3#) is delivered in week 7. Trial primary endpoint is progression free survival rate at 6 months (PFS6) with the aim to rule out a PFS6 rate of 50% in favor of 67.5%, with 80% power and a one-sided 0.05 significance level. Secondary endpoints include dysphagia relief, nutritional status change (patient weight, removal of enteral feeding tubes, PG-SGA score), quality of life, response rate, toxicity, overall survival and exploratory translational endpoints. PALEO is sponsored by the Australasian Gastro-Intestinal Trials Group (AGITG) for conduct at 8 sites in Australia and New Zealand. 6 of planned 54 patients have been enrolled. ACTRN12619001371189. Clinical trial information: Clinical trial information: ACTRN12619001371189 .

The use of Lutetium-177 PSMA radioligand therapy with high dose rate brachytherapy for locally recurrent prostate cancer after previous definitive radiation therapy: a randomized, single-institution, phase I/II study (ROADSTER).

BackgroundIsolated local failure (ILF) can occur in patients who initially receive definitive radiation therapy for prostate cancer. Salvage therapy for ILF includes high dose rate (HDR) brachytherapy. Prostate Specific Membrane Antigen (PSMA) Positron Emission Tomography (PET) can accurately detect ILF and can exclude extraprostatic disease. Lutetium-177 PSMA Radioligand Therapy (RLT) is a novel treatment for prostate cancer that can target prostate cancer accurately, while sparing radiation dose to normal tissues.MethodsROADSTER is a phase I/II randomized, single-institution study. Patients with an ILF of prostate cancer after definitive initial radiation therapy are eligible. The ILF will be confirmed with biopsy, magnetic resonance imaging (MRI) and PSMA PET. Patients will be randomized between HDR brachytherapy in two fractions (a standard of care salvage treatment at our institution) (cohort 1) or one treatment of intravenous Lutetium-177 PSMA RLT, followed by one fraction of HDR brachytherapy (cohort 2). The primary endpoints for the phase I portion of the study (n = 12) will be feasibility, defined as 10 or more patients completing the study protocol within 24 months of study activation; and safety, defined as zero or one patients in cohort 2 experiencing grade 3 or higher toxicity in the first 6 months post-treatment. If feasibility and safety are achieved, the study will expand to a phase II study (n = 30 total) where preliminary efficacy data will be evaluated. Secondary endpoints include changes in prostate specific antigen levels, acute toxicity, changes in quality of life, and changes in translational biomarkers. Translational endpoints will include interrogation of blood, urine, and tissue for markers of DNA damage and immune activation with each treatment.DiscussionROADSTER explores a novel salvage therapy for ILF after primary radiotherapy with combined Lutetium-177 PSMA RLT and HDR brachytherapy. The randomized phase I/II design will provide a contemporaneous patient population treated with HDR alone to facilitate assessment of feasibility, tolerability, and biologic effects of this novel therapy.Trial registrationNCT05230251 (ClinicalTrials.gov).

Abstract CT198: Immunomodulatory effects of the ATR inhibitor ceralasertib in a window of opportunity biomarker trial in patients with head and neck squamous cell carcinoma

Abstract Head and neck squamous cell carcinoma (HNSCC) is frequently locally advanced, but has a high risk of recurrence after initial treatment. Immune checkpoint blockade with PD-1/PD-L1 inhibitors has revolutionized treatment in the recurrent setting, but resistance to these therapies frequently occurs. Combination of checkpoint inhibitors with the ATR inhibitor ceralasertib could provide an exciting opportunity, with encouraging clinical activity reported in melanoma and non-small cell lung cancer (Kwon et al. 2022; Kim et al. 2022; Besse et al. OA15.05 IASLC 2022 WCLC). This phase 1b trial provided a unique opportunity to understand the immunomodulatory impact of DNA Damage Response (DDR) inhibitors in a clinical setting. NCT03022409 is an open-label, randomized window of opportunity trial where patients with HNSCC were treated with either the PARP inhibitor olaparib (300mg BID) or ceralasertib (160mg BID) for 9-21 days, prior to definitive surgery (or on-treatment biopsy). 21 patients were randomized; n=12 to ceralasertib and n=9 to olaparib, and ceralasertib data will be presented here. Translational endpoints on frozen and fixed tumor biopsies included spatial pharmacokinetics, pharmacodynamic biomarkers, multiplexed fluorescence of tumor infiltrating immune cells and gene expression panels. Blood assessments included cytokine detection, immune cell phenotyping and gene expression. Primary endpoint analysis utilized a bespoke prognostic immune-focused gene signature and secondary endpoint an IHC immunoscore, both aimed to measure if tumors would shift from a ‘cold’ to ‘hot/active’ immune state. We observed an ‘on-drug’ selective suppression of proliferating Ki67+ T-cells (but not total T-cells) in the tumor microenvironment and periphery, followed by a repopulation and median rebound of 63.8% and 187.5% above baseline levels for peripheral helper (CD4+Ki67+; n=8) and cytotoxic (CD8+Ki67+; n=7) T-cells respectively, when ceralasertib dose stopped. IL-12 plasma cytokine levels dropped on ceralasertib treatment and returned to baseline levels ‘off-drug’ in 8/10 patients. Type-I interferon (IFN1) gene expression associated signatures were also upregulated in PBMCs, suggestive of an immune priming effect. 0/2 and 2/4 patients on ceralasertib met their primary and secondary endpoints respectively, however, interpretation is limited due to small numbers of evaluable patients. 1 patient had a grade 3 serious adverse event of chest pain in the ceralasertib arm. There were no unexpected safety findings for either drug and adverse events were generally low grade. The translational data has generated new insights into the immunomodulatory effect of ceralasertib. Further evaluation of the combination of ceralasertib with immune checkpoint blockade is warranted to explore this novel immune mechanism of action. Citation Format: Gemma N. Jones, Sonia Iyer, Marta Milo, Pei-Jen Lou, Melonie A. Nance, Carlos A. Gomez-Roca, Nathan Standifer, Paola Marco-Casanova, Shaan Gill, Michael Surace, Richard Bystry, Maria Alexandrova, Sophie Willis, Jaime Rodriguez-Canales, Andreas Dannhorn, Bienvenu Loembé, Alan Lau, Natalia Lukashchuk, Elizabeth A. Harrington, Elhan Sanai, Emma Dean, Umamaheswar Duvvuri. Immunomodulatory effects of the ATR inhibitor ceralasertib in a window of opportunity biomarker trial in patients with head and neck squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr CT198.

Abstract P3-06-02: TATEN TRIAL (SOLTI-1716) Targeting non-Luminal disease by PAM50 with pembrolizumab + paclitaxel in Hormone Receptor-positive/HER2-negative (HR+/HER2-) metastatic breast cancer (MBC): interim analysis

Abstract Background Within HR+/HER2- disease, patients with non-luminal subtypes of breast cancer (HER2-enriched [HER2-E] and Basal-like) have poorer prognosis than those with luminal subtypes, may be more sensitive to chemotherapy, and have higher expression of immune-related genes and tumor infiltrating lymphocytes (TILs). Here, we report the interim efficacy and safety data of the TATEN trial (NCT04251169), the first study designed to evaluate pembrolizumab and paclitaxel in HR+/HER2-negative, PAM50 non-luminal, metastatic breast cancer (MBC). Methods TATEN is a single-arm, multicenter phase II study evaluating pembrolizumab in combination with paclitaxel in patients with HR+/HER2-, PAM50 non-luminal, MBC. Key inclusion criteria include progression to prior CDK4/6 inhibitors, presence of measurable disease by RECIST V1.1, no prior chemotherapy for MBC, and ECOG 0-1. Patients receive pembrolizumab at 200 mg every 3 weeks (on D1 of each 21-day cycle, beginning at cycle 1) in combination with weekly paclitaxel at 80 mg/m2, beginning at cycle 2. The primary endpoint is to evaluate overall response rate (ORR), defined as the rate of complete (CR) and partial response (PR) according to RECIST V1.1. Secondary endpoints include clinical benefit rate (CBR; CR + PR + stable disease >24 weeks), progression free survival, overall survival, safety, and predictive biomarkers. Tumor samples collected during advanced/metastatic disease are mandatory to assess PAM50 and other translational endpoints. This study had a planned interim analysis after 15 patients were evaluable for ORR based on a Simon’s two stage design with 80% power and a type I error rate of 0.05. Stage I of the trial would be considered successful if at least 6 patients achieved a PR and/or CR. In that case, the trial would recruit up to 46 evaluable patients for a target ORR ≥ 41. Here we report results from the patients who received at least one dose of combination treatment and had a first, post-baseline, tumor assessment according to RECIST v1.1 (evaluable population). Results From July 2020 to December 2021, 119 patients were screened, and 25 PAM50 non-luminal tumors were identified (21%). From these, 17 (68%) patients were recruited, and 15 were evaluable for primary endpoint. Two patients discontinued the trial before the first dose of pembrolizumab and paclitaxel, because of clinical progressive disease (PD). Baseline patient characteristics were as follows: median age 53 years (range: 40-77), ECOG 0 52.9%, de novo MBC at diagnosis 29.4%, and visceral disease 64.7% (including 53.3% with liver metastasis). Ten patients had received paclitaxel treatment in the adjuvant setting. Regarding PAM50 intrinsic subtype, two patients had basal-like and 13 HER2-E tumors. At the time of data cut-off (May 17,2022), 8 patients (53.3%) had stopped their treatment because of PD and 2 (13.3%) due to toxicity. Five patients (33.3%) were still on treatment. The ORR was 53.3 % (8 of 15, 95% CI 26.6-78.7), meeting the pre-specified ORR for the first stage of the trial. The CBR was 86.6% (13 of 15, 95%CI 59.5-98.34), and median PFS was 7.5 months (95% CI: 5.6 – 10.2). Overall, all patients experienced treatment-related adverse events (TRAEs) of any grade, while 53.3% of patients experienced grade 3 TRAEs. No grade 4 or 5 TRAEs were reported in the evaluable population. Correlative analysis including gene expression analysis and centralized TILs scoring and PD-L1 IHC will be presented. Conclusions The first stage of TATEN combining pembrolizumab with paclitaxel after progression to CDK4/6 inhibitors in patients with HR+/HER2-negative, PAM50 non-luminal MBC met its pre-specified endpoint. Completion of the stage II part of the trial with the inclusion of up to 46 patients is warranted to assess the activity of this combination in this group of patients. Correlative studies to find predictive biomarkers of response to this regimen are ongoing and will be presented at the meeting. This study was funded by MSD. Citation Format: Aleix Prat, Tomás Pascual, Montserrat Muñoz, Cristina Hernando, Silvia Vazquez, Salvador Blanch, Manuel Alva, Mafalda Oliveira, Esther Sanfeliu, Lorea Villanueva, Fara Brasó-Maristany, Nuria Chic, Eva Ciruelos. TATEN TRIAL (SOLTI-1716) Targeting non-Luminal disease by PAM50 with pembrolizumab + paclitaxel in Hormone Receptor-positive/HER2-negative (HR+/HER2-) metastatic breast cancer (MBC): interim analysis [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-06-02.

Abstract PD11-04: PD11-04 Primary results of SOLTI-1503 PROMETEO phase 2 trial of Combination of Talimogene Laherparepvec (T-VEC) with Atezolizumab in patients with residual breast cancer after standard neoadjuvant multi-agent chemotherapy

Abstract Background: Residual disease (RD) following neoadjuvant chemotherapy (NAC) in early HER2-negative breast cancer (BC) remains an unmet medical need. However, no therapies to date have tested their activity directly in chemo-resistant RD. Here, we hypothesized that combining an oncolytic virus such as T-VEC with atezolizumab may offer clinical benefit in patients (pts) with RD after standard NAC. To our knowledge, PROMETEO is the first trial that examines the activity of immunotherapy in pts with RD prior to surgery. Methods: PROMETEO (NCT03802604) is a single-arm, open-label, multicenter phase II trial. Women with triple-negative BC (TNBC) or hormone receptor-positive/HER2-negative (HR+/HER2-) BC with baseline (i.e., before NAC) ki67 ≥ 20% were eligible. RD was confirmed with a magnetic resonance imaging (MRI) showing a tumor diameter ≥ 10 mm and a core-biopsy detecting the presence of invasive cells. Before surgery, T-VEC was administered intratumorally on week 1 (106 pfu/mL), then in week 4 and every 2 weeks thereafter (108 pfu/mL) for 4 injections. Atezolizumab (840 mg) was administered intravenously every 2 weeks for 4 infusions, starting at week 4. Surgery was performed in < 3 weeks after completing the treatment. The primary objective was to evaluate the efficacy of the combination, measured by the rate of residual cancer burden (RCB) class 0/1 at surgery. Tumor samples collected at 5 timepoints (before NAC, during screening period, after first dose of T-VEC, after first dose of T-VEC and atezolizumab and at surgery) were mandatory to assess gene expression, tumor-infiltrating lymphocytes (TILs), immune cells PD-L1 IHC (SP142), tumor mutational burden (TMB) by FoundationOne and other translational endpoints. Results: Between Dec 2018 to Feb 2022, 28 pts were enrolled: 20 pts with HR+/HER2- disease and 8 pts with TNBC. Median age was 47 (range 31-71) and 71% of pts were premenopausal. At diagnosis before NAC, clinical stage II disease represented 60.7%, cN+ 60.7%, median Ki-67 was 37.5% (range 20%-95%), high TILs (≥10%) 37%, median TMB was 3 (0-19) and only 1 of 27 pts (3.7%) had a PD-L1-positive tumor. After NAC, mean tumor size by MRI was 28.3 mm (10-93). Two pts discontinued from the trial (1 withdrawal of consent and 1 COVID infection). The completion of 5 cycles of treatment was achieved by 73% of pts. The overall RCB-0/1 rate was 25% (7 of 28, 95% IC 10.7 – 44.9%), all with RCB 0 (pathologic complete response [pCR]). The pCR rate was 30% in HR+/HER2- disease and 12.5 % in TNBC. Radiological response by MRI was achieved by 3 of 28 pts (10.7%). Interestingly, none of the 7 pts with a pCR had radiological response (stable disease n=5, progressive disease [PD] n=2). Six pts (21.4%) had radiological PD and had RCB 2/3. Overall, 27 (96%) patients had at least one treatment-emergent adverse event (TEAE) of any grade. Most common grade 1 or 2 AEs were fever (11 pts, 39.3%), ALT increased (9 pts, 32.1%), AST increased (8 pts, 28.6%), arthralgia (6 pts, 21.4%) and anemia (6 pts, 21.4%). Grade 3 reversible neutropenia occurred in 1 patient. Across all pts, significant increases (p< 0.001) in TILs, immune genes and immune PDL1+ cells were observed after 1 dose of TVEC, 1 dose of the combination and at surgery. Intrinsic subtype changes at surgery occurred in 73.1% of cases, mostly (46.1%) Luminal A/B converting to Normal-like. At surgery, 19 of 26 (73.1%) of tumors were PDL1+. Conclusions: Two months of T-VEC in combination with atezolizumab induced a pCR in a subgroup of pts with chemoresistant HER2- breast cancer. This effect is probably related to the immune activation provoked by the combined treatment. Interestingly, a high discrepancy was observed between the pre-surgical radiological imaging and the actual surgical pathological report. Pre-operative window-of-opportunity trials in this context might provide important clues regarding the activity of novel treatment strategies. Citation Format: Tomás Pascual, Maria Vidal, Juan Miguel Cejalvo, Estela Vega, Esther Sanfeliu, Sergi Ganau, Ana Julve, Esther Zamora, Ignacio Miranda, Ana Delgado, Begoña Bermejo, Luis de la Cruz-Merino, Manel Juan, Patricia Galván, Xavier Gonzalez-Farré, Juan Manuel Ferrero-Cafiero, Patricia Villagrasa, Mafalda Oliveira, Aleix Prat. PD11-04 Primary results of SOLTI-1503 PROMETEO phase 2 trial of Combination of Talimogene Laherparepvec (T-VEC) with Atezolizumab in patients with residual breast cancer after standard neoadjuvant multi-agent chemotherapy [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr PD11-04.