PurposeWe conducted a phase I/II study to evaluate durvalumab (D; anti-PD-L1) in combination with tremelimumab (T; anti–cytotoxic T-lymphocyte antigen 4) in pediatric patients with relapsed/refractory solid tumors.Patients and methodsThe dose-finding phase (phase I) assessed the safety and pharmacokinetics of D+T at two dose levels to determine the recommended phase II dose (RP2D). The primary endpoint for the dose-expansion phase (phase II) was antitumor activity (by Response Evaluation Criteria in Solid Tumors v1.1) at the RP2D. Assessment of circulating cells reflecting immune cell activation was a secondary endpoint.ResultsBased on safety and pharmacokinetic data in the dose-finding phase (n = 29), the adult-equivalent RP2D was determined as D (30 mg/kg) + T (1 mg/kg). In the dose-expansion phase, 21 patients (sarcoma, n = 11; solid tumors, n = 10) were treated at the RP2D. Of patients with sarcoma, none achieved an objective response and one had stable disease ≥7 weeks. Of the patients with solid tumors, one (chordoma) had a confirmed partial response (10.8 months duration) and one (renal cell carcinoma) had stable disease ≥7 weeks. Treatment-related adverse events occurred in 76% of patients (19% as grade 3 or 4). No adverse events leading to death were reported. Across both phases treatment with D+T resulted in an increase in CD4+Ki67+ T cells.ConclusionsD (30 mg/kg) + T (1 mg/kg) had limited antitumor activity in this pediatric population; however, the safety profile was manageable and consistent with the known safety profile in adult patients, with no new safety concerns identified.Clinical trial registrationClinicalTrials.gov, identifier NCT03837899; EudraCT, identifier 2018-003118-42.

[This corrects the article DOI: 10.3389/fonc.2026.1680081.].

More effective therapies are required for advanced breast cancer. We report results from 58 women with locally advanced unresectable or metastatic hormone-receptor (HR)-negative, human epidermal growth factor receptor 2 (HER2)-low breast cancer enrolled in arm 6 of the multicenter, open-label phase 1b/2 BEGONIA platform trial, who received durvalumab (1,120 mg) plus trastuzumab deruxtecan (T-DXd; 5.4 mg kg-1) intravenously every 3 weeks as first-line treatment. Objective response rate (ORR) and safety were primary endpoints; duration of response (DoR), progression-free survival (PFS) and overall survival (OS) were secondary endpoints. Median follow-up was 20.6 months (range: 1-37). ORR was 62.1% (95% confidence interval (CI): 48.4-74.5), which did not meet the protocol-specified objective of 38/57 (66.6%) responses. Median DoR was 15.2 months (95% CI: 8.44-not calculable), PFS was 12.6 months (95% CI: 8.4-16.3) and OS was 30.3 months (95% CI: 18.8-not calculable). The safety profile of the combination treatment was consistent with those of the individual therapies. Adjudicated, drug-related interstitial lung disease or pneumonitis occurred in 20.7% of participants (grades 1 and 2, 19.0%; grade 5, 1.7%). Durvalumab plus T-DXd demonstrated clinically relevant efficacy for first-line treatment of metastatic HR-negative, HER2-low breast cancer, with no unexpected toxicities observed. ClinicalTrials.gov identifier: NCT03742102 .

Introduction: The phase 1 CLOVER study (NCT03509012) evaluated durvalumab with or without tremelimumab in combination with concurrent chemoradiotherapy (cCRT) in patients with advanced solid tumors; here, we report findings from the limited-stage SCLC (LS-SCLC) cohort. Methods: Patients with pathologically confirmed LS-SCLC whose disease could be encompassed within a radical radiation portal received durvalumab (arms 1 and 2) or durvalumab plus tremelimumab (arms 3 and 4) in combination with cCRT (cisplatin-etoposide and either standard radiotherapy [arms 1 and 3] or hyperfractionated radiotherapy [arms 2 and 4]). The primary end point was safety and tolerability. Preliminary efficacy and candidate biomarkers of response were assessed. Results: Overall, 33 patients were enrolled: 12 in arm 1, 12 in arm 2, six in arm 3, and three in arm 4. No patients had dose-limiting toxicity. Grade 3 or 4 adverse events occurred in 79.2% of patients from arms 1 and 2 and 88.9% from arms 3 and 4; the most common were hematologic events. In arms 1, 2, 3, and 4, objective response rate was 66.7%, 66.7%, 83.3%, and 100.0%, disease control rate was 90.9%, 100.0%, 100.0%, and 100.0% at 18 weeks and 72.7%, 83.3%, 100.0%, and 100.0% at 48 weeks, and the median progression-free survival (PFS) (95% confidence interval) was 9.2 months (5.3‒not estimable [NE]), 16.6 months (8.4–NE), not reached (16.6–NE), and 9.3 months (6.3–NE), respectively. In exploratory biomarker analyses, no difference in PFS by programmed cell death-ligand 1 expression level was observed; median PFS was numerically greater in high versus low tumor inflammation signature and CD8A expression subgroups. Conclusions: Durvalumab in combination with cCRT, with or without tremelimumab, was tolerable and active in patients with LS-SCLC.

Single-cell RNA-seq (scRNAseq) struggles to capture the cellular heterogeneity of transcripts within individual cells due to the prevalence of highly abundant and ubiquitous transcripts, which can obscure the detection of biologically distinct transcripts expressed up to several orders of magnitude lower levels. To address this challenge, here we introduce single-cell CRISPRclean (scCLEAN), a molecular method that globally recomposes scRNAseq libraries, providing a benefit that cannot be recapitulated with deeper sequencing. scCLEAN utilizes the programmability of CRISPR/Cas9 to target and remove less than 1% of the transcriptome while redistributing approximately half of reads, shifting the focus toward less abundant transcripts. We experimentally apply scCLEAN to both heterogeneous immune cells and homogenous vascular smooth muscle cells to demonstrate its ability to uncover biological signatures in different biological contexts. We further emphasize scCLEAN's versatility by applying it to a third-generation sequencing method, single-cell MAS-Seq, to increase transcript-level detection and discovery. Here we show the possible utility of scCLEAN across a wide array of human tissues and cell types, indicating which contexts this technology proves beneficial and those in which its application is not advisable.

BACKGROUND:Patients with high-risk non-muscle-invasive bladder cancer (NMIBC) often have recurrence or progression after transurethral resection of bladder tumour (TURBT) and subsequent BCG therapy. We aimed to evaluate whether 1 year of durvalumab with BCG could improve outcomes versus BCG alone for these patients. METHODS:This randomised, open-label, phase 3 trial enrolled patients aged 18 years or older with BCG-naive, high-risk NMIBC who underwent TURBT. Patients were randomly allocated (1:1:1) to receive intravenous durvalumab (every 4 weeks for 13 cycles) plus intravesical BCG induction (weekly for 6 weeks) and maintenance (three doses at weekly intervals at 3, 6, 12, 18, and 24 months), durvalumab plus BCG induction, or BCG induction and maintenance (comparison group). The primary endpoint was investigator-assessed disease-free survival in the durvalumab plus BCG induction and maintenance group versus the comparison group in the intention-to-treat population. This study is registered at ClinicalTrials.gov (NCT03528694) and EudraCT (2017-002979-26) and is ongoing but is no longer enrolling patients. FINDINGS:Between June 18, 2018, and Oct 2, 2020, 1350 patients were assessed for eligibility, among whom 1018 patients were randomly allocated: 339 to the durvalumab plus BCG induction and maintenance group (of whom 336 [99%] initiated and 180 [53%] completed treatment), 339 to the durvalumab plus BCG induction group (337 [99%] initiated and 239 [71%] completed treatment), and 340 to the comparison group (339 [>99%] initiated and 182 [54%] completed treatment). At a median follow-up of 60·7 months (IQR 51·5-66·5), there were 67 (20%) disease-free survival events in the durvalumab plus BCG induction and maintenance group and 98 (29%) events in the comparison group, resulting in a 32% reduction in the risk of recurrence of high-risk disease or death by any cause with durvalumab plus BCG induction and maintenance versus the comparison group (hazard ratio 0·68 [95% CI 0·50-0·93]; log-rank p=0·015). Among patients who received at least one dose of study treatment, grade 3 or 4 treatment-related adverse events occurred in 71 (21%) of 336 patients in the durvalumab plus BCG induction and maintenance group, 52 (15%) in the durvalumab plus BCG induction only group, and 13 (4%) of 339 patients in the comparison group. No treatment-related adverse events led to death. INTERPRETATION:Among patients with BCG-naive, high-risk NMIBC, 1 year of durvalumab combined with BCG induction and maintenance therapy showed a statistically significant and clinically meaningful improvement in disease-free survival versus BCG induction and maintenance alone. The combination had a manageable safety profile, consistent with that of the individual therapies. These results support 1 year of durvalumab in combination with BCG induction and maintenance therapy as a potential new treatment for this patient population. FUNDING:AstraZeneca.

Abstract Purpose: The phase II, multiarm, signal-searching BALTIC study (NCT02937818) assessed novel treatment combinations for platinum-refractory/resistant extensive-stage small cell lung cancer (ES-SCLC). Patients and Methods: Patients with ES-SCLC with progressive disease during or within 90 days of completing first-line platinum-based chemotherapy received one of three regimens: durvalumab plus tremelimumab followed by durvalumab monotherapy (arm A), adavosertib plus carboplatin (arm B), or ceralasertib plus olaparib (arm C). The primary endpoint was the objective response rate. Prespecified exploratory biomarker analyses were conducted in arms A and C. Results: In arm A (n = 41), arm B (n = 10), and arm C (n = 21), the confirmed objective response rates were 7.3%, 0%, and 4.8%, respectively. Safety profiles in all arms were consistent with those of the individual drugs. In arm A, patients with PD-L1 expression (tumor cells or immune cells) ≥1% seemed to have a greater likelihood of achieving disease control with durvalumab plus tremelimumab than those with PD-L1 (tumor cells and immune cells) <1%, and lower baseline ctDNA and reduction in the on-treatment ctDNA level were both associated with longer overall survival. Among patients treated with ceralasertib plus olaparib in arm C, specific immune response-relevant circulating chemokines and cytokines were identified as early biomarkers of survival and pharmacodynamic biomarkers. Conclusions: In BALTIC, all combination regimens demonstrated tolerable safety profiles, but antitumor activity was limited in refractory/resistant ES-SCLC. Among patients treated with durvalumab plus tremelimumab, an association of on-treatment reduction in ctDNA with longer overall survival suggests the potential use of ctDNA as a surrogate of treatment response, warranting further investigation.

BACKGROUND Neoadjuvant chemotherapy followed by radical cystectomy is the standard treatment for cisplatin-eligible patients with muscle-invasive bladder cancer. Adding perioperative immunotherapy may improve outcomes. METHODS In this phase 3, open-label, randomized trial, we assigned, in a 1:1 ratio, cisplatin-eligible patients with muscle-invasive bladder cancer to receive neoadjuvant durvalumab plus gemcitabine-cisplatin every 3 weeks for four cycles, followed by radical cystectomy and adjuvant durvalumab every 4 weeks for eight cycles (durvalumab group), or to receive neoadjuvant gemcitabine-cisplatin followed by radical cystectomy alone (comparison group). Event-free survival was one of two primary end points. Overall survival was the key secondary end point. RESULTS In total, 533 patients were assigned to the durvalumab group and 530 to the comparison group. The estimated event-free survival at 24 months was 67.8% (95% confidence interval [CI], 63.6 to 71.7) in the durvalumab group and 59.8% (95% CI, 55.4 to 64.0) in the comparison group (hazard ratio for progression, recurrence, not undergoing radical cystectomy, or death from any cause, 0.68; 95% CI, 0.56 to 0.82; P<0.001 by stratified log-rank test). The estimated overall survival at 24 months was 82.2% (95% CI, 78.7 to 85.2) in the durvalumab group and 75.2% (95% CI, 71.3 to 78.8) in the comparison group (hazard ratio for death, 0.75; 95% CI, 0.59 to 0.93; P = 0.01 by stratified log-rank test). Treatment-related adverse events of grade 3 or 4 in severity occurred in 40.6% of the patients in the durvalumab group and in 40.9% of those in the comparison group; treatment-related adverse events leading to death occurred in 0.6% in each group. Radical cystectomy was performed in 88.0% of the patients in the durvalumab group and in 83.2% of those in the comparison group. CONCLUSIONS Perioperative durvalumab plus neoadjuvant chemotherapy led to significant improvements in event-free survival and overall survival as compared with neoadjuvant chemotherapy alone.

The lack of preparedness for detecting and responding to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pathogen (i.e., COVID-19) has caused enormous harm to public health and the economy. Testing strategies deployed on a population scale at day zero, i.e., the time of the first reported case, would be of significant value. Next-generation sequencing (NGS) has such capabilities; however, it has limited detection sensitivity for low-copy-number pathogens. Here, we leverage the CRISPR-Cas9 system to effectively remove abundant sequences not contributing to pathogen detection and show that NGS detection sensitivity of SARS-CoV-2 approaches that of RT-qPCR. The resulting sequence data can also be used for variant strain typing, co-infection detection, and individual human host response assessment, all in a single molecular and analysis workflow. This NGS work flow is pathogen agnostic and, therefore, has the potential to transform how large-scale pandemic response and focused clinical infectious disease testing are pursued in the future.

Programmed cell death ligand-1 (PD-L1), expressed on both tumor cells (TC) and tumor-associated immune cells (IC), has been shown to be a useful biomarker and predictive of response to anti-PD-L1 agents in certain tumor types. In recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC), there is a growing interest in the role of PD-L1 expression on ICs, as well as TCs, for predicting response to immune checkpoint inhibitors. Using pooled data from the phase II HAWK and CONDOR studies, we investigated the association of baseline PD-L1 expression with durvalumab efficacy in patients with R/M HNSCC. To determine an optimal PD-L1 cut-off point for predicting survival, we assessed PD-L1 expression levels at different TC and IC cut-off points in patients treated with durvalumab. Longer survival was associated with higher TC membrane PD-L1 expression and IC staining. When the combined TC/IC algorithm was applied, a cut-off point for PD-L1 expression of ≥50% on TCs or ≥25% on ICs (TC ≥ 50%/IC ≥ 25%) showed a higher objective response rate (17.2% vs. 8.8%), longer median progression-free survival (2.8 vs. 1.9 months), and longer median overall survival (8.4 vs. 5.4 months) in the PD-L1–high versus PD-L1–low/negative patient populations, respectively. A scoring algorithm combining PD-L1 expression on TCs and ICs using the cut-off point TC ≥ 50%/IC ≥ 25% was optimal for identifying patients with HNSCC most likely to benefit from durvalumab treatment. The new algorithm is robust and can be reproducibly scored by trained pathologists. Significance: A novel algorithm for PD-L1 expression using the cut-off point TC ≥ 50%/IC ≥ 25% is robust for identifying patients with HNSCC most likely to benefit from durvalumab treatment and can be reproducibly scored by trained pathologists.

ABSTRACTThe spatial organisation of cells defines the biological functions of tissue ecosystems from development to disease. Recently, an array of technologies have been developed to query gene expression in a spatial context. These include techniques such as employing barcoded oligonucleotides, single-molecule fluorescence in situ hybridization (smFISH), and DNA nanoball (DNB)-patterned arrays. However, resolution and efficiency vary across platforms and technologies. To obtain spatially relevant biological information from spatially resolved transcriptomics, we combined the Stereo-seq workflow with CRISPRclean technology to develop the STOmics-GenX pipeline. STOmics-GenX not only allowed us to reduce genomic, mitochondrial, and ribosomal reads, but also lead to a ∼2.1-fold increase in the number of detected genes when compared to conventional Stereo-seq (STOmics). Additionally, the STOmics-GenX pipeline resulted in an improved detection of cell type specific genes, thereby improving cellular annotations. Most importantly, STOmics-GenX allowed for enhanced detection of clinically relevant biomarkers such as Alpha-fetoprotein (AFP), enabling the identification of two spatially distinct subsets of hepatocytes in hepatocellular carcinoma tissue. Thereby, combining CRISPRclean technology with STOmics not only allowed improved gene detection but also paved the way for spatial precision oncology by improved detection of clinically relevant biomarkers.

ABSTRACTThe lack of preparedness for detecting the highly infectious SARS-CoV-2 pathogen, the pathogen responsible for the COVID-19 disease, has caused enormous harm to public health and the economy. It took ∼60 days for the first reverse transcription quantitative polymerase chain reaction (RT-qPCR) tests for SARS-CoV-2 infection developed by the United States Centers for Disease Control (CDC) to be made publicly available. It then took >270 days to deploy 800,000 of these tests at a time when the estimated actual testing needs required over 6 million tests per day. Testing was therefore limited to individuals with symptoms or in close contact with confirmed positive cases. Testing strategies deployed on a population scale at ‘Day Zero’ i.e., at the time of the first reported case, would be of significant value. Next Generation Sequencing (NGS) has such Day Zero capabilities with the potential for broad and large-scale testing. However, it has limited detection sensitivity for low copy numbers of pathogens which may be present. Here we demonstrate that by using CRISPR-Cas9 to remove abundant sequences that do not contribute to pathogen detection, NGS detection sensitivity of COVID-19 is comparable to RT-qPCR. In addition, we show that this assay can be used for variant strain typing, co-infection detection, and individual human host response assessment, all in a single workflow using existing open-source analysis pipelines. This NGS workflow is pathogen agnostic, and therefore has the potential to transform how both large-scale pandemic response and focused clinical infectious disease testing are pursued in the future.SIGNIFICANCE STATEMENTThe lack of preparedness for detecting infectious pathogens has had a devastating effect on the global economy and society. Thus, a ‘Day Zero’ testing strategy, that can be deployed at the first reported case and expanded to population scale, is required. Next generation sequencing enables Day Zero capabilities but is inadequate for detecting low levels of pathogen due to abundant sequences of little biological interest. By applying the CRISPR-Cas system to remove these sequences in vitro, we show sensitivity of pathogen detection equivalent to RT-qPCR. The workflow is pathogen agnostic, and enables detection of strain types, co-infections and human host response with a single workflow and open-source analysis tools. These results highlight the potential to transform future large-scale pandemic response.

Background: Molecular response based on ctDNA dynamics may be predictive of benefit from immunotherapy in NSCLC, complementing radiologic disease assessment and potentially enabling early clinical decision-making, but data in SCLC are lacking. The phase 2, multi-arm, signal-searching BALTIC study (NCT02937818) assessed novel treatment combinations in platinum-refractory/resistant ES-SCLC; we report efficacy, safety, and exploratory ctDNA and PD-L1 analyses from pts who received D + T in Arm A. Methods: Eligible pts had ES-SCLC, progressive disease (PD) during or within 90 days of completing 1L platinum-based CT, WHO PS 0-1, and life expectancy ≥8 weeks. In Arm A, pts received D 1500 mg + T 75 mg q4w for 4 cycles, followed by maintenance D 1500 mg q4w until PD. The primary endpoint was ORR (investigator assessment, RECIST v1.1). Secondary endpoints included DCR, PFS, OS, and safety and tolerability. Prespecified exploratory analyses included assessment of baseline/on-treatment ctDNA levels measured by maximum variant allele frequency (MaxVAF), and PD-L1 expression on tumor cells (TC) and immune cells (IC) (VENTANA PD-L1 [SP263] Assay). Results: 41 pts received treatment with D + T (median age 63 years; 76% male; 76% PS 1). At the data cut-off (DCO; Jun 22, 2020), median treatment duration was 12 weeks, with 3 pts ongoing D treatment (these pts had received ≥38, ≥21, and ≥19 doses of D, respectively, at DCO). Confirmed ORR was 7.3% (95% CI 1.54‒19.92; 3 partial responses [PR]). DCR at 12 weeks was 27%. 21 pts (51%) were PD-L1 evaluable. Of 12 pts with PD-L1 expression (TC or IC) ≥1%, 3 (25%) had a best response of PR or stable disease, compared with 1 (11%) of 9 pts with PD-L1 (TC or IC) <1%. Median PFS was 1.84 mo (95% CI 1.77‒1.91) and median OS was 5.36 mo (95% CI 2.89‒7.23). Grade 3/4 treatment-related adverse events (TRAEs) occurred in 8 pts (20%); TRAEs led to treatment discontinuation in 5 pts (12%) and death in 1 pt (hemorrhagic enterocolitis). 26 pts (63%) were evaluable for ctDNA at baseline, and 10 pts (24%) had on-treatment ctDNA data. Pts with baseline MaxVAF in low (n=9), medium (n=8), and high (n=9) tertiles had a median OS of 12.8, 4.5, and 2.3 mo, respectively. Pts with a decrease in on-treatment ctDNA level (delta MaxVAF <0) had a longer median OS (12.0 mo) vs those with an increase (5.6 mo). Conclusions: Although limited antitumor activity was observed in refractory/resistant ES-SCLC in BALTIC, association of lower baseline ctDNA levels (MaxVAF) with longer OS may reflect the prognostic effect of disease burden. Association of on-treatment reduction in ctDNA level with longer OS suggests potential use of ctDNA as a surrogate of treatment response in ES-SCLC. Further analyses in larger datasets and in a randomized setting are warranted. Citation Format: Niels Reinmuth, Oscar Juan-Vidal, Zsolt Horváth, Dariusz Kowalski, Anna Kryzhanivska, Eszter Csánky, Gabriella Gálffy, Maciej Bryl, David Vicente, Ihor Vynnychenko, Zsolt Pápai-Székely, Jon Armstrong, Tapashi Dalvi, Yashaswi Shrestha, Mingchao Xie, Haiyi Jiang, Igor Bondarenko. Durvalumab (D) plus tremelimumab (T) in platinum-refractory/resistant extensive-stage small cell lung cancer (ES-SCLC): Efficacy, safety and ctDNA dynamics from Arm A of the phase 2 BALTIC study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT533.

Single-cell transcriptomics suffers from lapses in coverage of the full transcriptome, providing an incomplete gene expression profile of the cell. Here, we introduce single-cell CRISPRclean (scCLEAN), an in vitro molecular method that can be universally inserted into any single-cell RNA-seq workflow to improve the sensitivity of the assay. Utilizing CRISPR/Cas9, scCLEAN works to selectively remove highly abundant uninformative molecules, redistributing ~50% of reads to enrich for lowly expressed transcripts. Utilizing immune cells, we describe a validation of scCLEAN showing a 2.1-fold enrichment in library complexity with negligible off-target effects. Subsequently, applying scCLEAN to single-cell iso-seq samples results in a 4.6-fold improvement in unique isoform detection. Thus, demonstrating a benefit in short and long read sequencing applications. Finally, we illustrate the ability of scCLEAN to elucidate biological insights by applying it to two participant cohorts of cardiovascular samples, bringing to light novel molecular characteristics including inflammatory signatures.

Anti-PD-1 therapy can provide long, durable benefit to a fraction of patients. The on-label PD-L1 test, however, does not accurately predict response. To build a better biomarker, we created a method called T Cell Subtype Profiling (TCSP) that characterizes the abundance of T cell subtypes (TCSs) in FFPE specimens using five RNA models. These TCS RNA models are created using functional methods, and robustly discriminate between naïve, activated, exhausted, effector memory, and central memory TCSs, without the reliance on non-specific, classical markers. TCSP is analytically valid and corroborates associations between TCSs and clinical outcomes. Multianalyte biomarkers based on TCS estimates predicted response to anti-PD-1 therapy in three different cancers and outperformed the indicated PD-L1 test, as well as Tumor Mutational Burden. Given the utility of TCSP, we investigated the abundance of TCSs in TCGA cancers and created a portal to enable researchers to discover other TCSP-based biomarkers.

BACKGROUND:In the phase III CASPIAN study, first-line durvalumab in combination with etoposide plus either cisplatin or carboplatin (EP) significantly improved overall survival (OS) versus EP alone in extensive-stage small-cell lung cancer (ES-SCLC). Durvalumab plus tremelimumab plus EP numerically improved OS versus EP, but did not reach statistical significance. Here we report updated OS in censored patients after median follow-up of >3 years.PATIENTS AND METHODS:805 patients with treatment-naïve ES-SCLC were randomized 1 : 1 : 1 to durvalumab plus EP, durvalumab plus tremelimumab plus EP, or EP. The two primary endpoints were OS for durvalumab plus EP versus EP and for durvalumab plus tremelimumab plus EP versus EP.RESULTS:As of 22 March 2021 (median follow-up 39.4 months, 86% maturity), durvalumab plus EP continued to demonstrate improved OS versus EP: hazard ratio (HR) 0.71 [95% confidence interval (CI) 0.60-0.86; nominal P = 0.0003]; median OS was 12.9 versus 10.5 months, and 36-month OS rate was 17.6% versus 5.8%. Durvalumab plus tremelimumab plus EP continued to numerically improve OS versus EP: HR 0.81 (95% CI: 0.67-0.97; nominal P = 0.0200); median OS was 10.4 months, and 36-month OS rate was 15.3%. Twenty-seven and nineteen patients in the durvalumab plus EP and durvalumab plus tremelimumab plus EP arms, respectively, remained on durvalumab treatment at data cut-off.CONCLUSIONS:Three times more patients were estimated to be alive at 3 years when treated with durvalumab plus EP versus EP, with the majority still receiving durvalumab at data cut-off, further establishing durvalumab plus EP as first-line standard of care for ES-SCLC.

As immuno-oncology drugs grow more popular in the treatment of cancer, better methods are needed to quantify the tumor immune cell component to determine which patients are most likely to benefit from treatment. Methods such as flow cytometry can accurately assess the composition of infiltrating immune cells; however, they show limited use in formalin-fixed, paraffin-embedded (FFPE) specimens. This article describes a novel hybrid-capture RNA sequencing assay, ImmunoPrism, that estimates the relative percentage abundance of eight immune cell types in FFPE solid tumors. Immune health expression models were generated using machine learning methods and used to uniquely identify each immune cell type using the most discriminatively expressed genes. The analytical performance of the assay was assessed using 101 libraries from 40 FFPE and 32 fresh-frozen samples. With defined samples, ImmunoPrism had a precision of +/- 2.72%, a total error of 2.75%, and a strong correlation (r(2) = 0.81; P < 0.001) to flow cytometry. ImmunoPrism had similar performance in dissociated tumor cell samples (total error of 8.12%) and correlated strongly with immunohistochemistry (CD8: r(2) = 0.83; P < 0.001) in FFPE samples. Other performance metrics were determined, including limit of detection, reportable range, and reproducibility. The approach used for analytical validation is shared here so that it may serve as a helpful framework for other laboratories when validating future complex RNA-based assays.

9002 Background: CASPIAN is an open-label, Phase 3 study of durvalumab (D) ± tremelimumab (T) + etoposide and either cisplatin or carboplatin (EP) for pts with 1L ES-SCLC. At the planned interim analysis (data cutoff Mar 11, 2019; 63% maturity), D + EP demonstrated a statistically significant improvement in OS compared with EP alone (HR 0.73 [95% CI 0.59–0.91]; p=0.0047). Here we present a planned updated analysis of OS for D + EP vs EP and the first results for D + T + EP vs EP. Methods: Treatment-naïve pts with ES-SCLC (WHO PS 0/1) were randomized 1:1:1 to D 1500 mg + EP q3w, D 1500 mg + T 75 mg + EP q3w, or EP q3w. In the IO arms, pts received 4 cycles of EP + D ± T, followed by maintenance D 1500 mg q4w until disease progression. Pts received one additional dose of T 75 mg post EP in the D + T + EP arm. In the EP arm, pts received up to 6 cycles of EP and optional PCI (investigator’s discretion). The two primary endpoints were OS for D + EP vs EP and for D + T + EP vs EP. Results: 268, 268 and 269 pts were randomized to D + EP, D + T + EP and EP, respectively; baseline characteristics were generally well balanced across arms. As of Jan 27, 2020, the median follow-up was 25.1 mo, 82% maturity. D + EP continued to demonstrate improvement in OS vs EP, with a HR of 0.75 (95% CI 0.62–0.91; nominal p=0.0032); median OS 12.9 vs 10.5 mo, respectively. 22.2% of pts were alive at 2 y with D + EP vs 14.4% of pts with EP. D + T + EP numerically improved OS vs EP, however this did not reach statistical significance per the prespecified statistical plan: HR 0.82 (95% CI 0.68–1.00; p=0.0451 [p≤0.0418 required for stat sig]); the median OS was 10.4 mo and 23.4% of pts were alive at 2 y. Secondary endpoints of PFS and ORR remained improved with D + EP vs EP and will be presented. Confirmed investigator-assessed ORR was similar for D + T + EP vs EP (58.4% vs 58.0%). Median PFS was similar for D + T + EP vs EP (4.9 mo vs 5.4 mo), but the 12-mo PFS rate was numerically higher (16.9% vs 5.3%); PFS HR 0.84 (95% CI 0.70–1.01). In the D + EP, D + T + EP and EP arms, respectively, incidences of all-cause AEs of Grade 3/4 were 62.3%, 70.3% and 62.8%; AEs leading to discontinuation 10.2%, 21.4% and 9.4%; and AEs leading to death 4.9%, 10.2% and 5.6%. Conclusions: The addition of durvalumab to EP continued to demonstrate improvement in OS compared with a robust control arm, further supporting this regimen as a new standard of care for 1L ES-SCLC offering the flexibility of platinum choice. No additional benefit was observed when T was combined with D + EP in this pt population. Safety findings in all arms remained consistent with the known safety profiles of all agents. Clinical trial information: NCT03043872.