Tiragolumab plus atezolizumab versus placebo plus atezolizumab as a first-line treatment for PD-L1-selected non-small-cell lung cancer (CITYSCAPE): primary and follow-up analyses of a randomised, double-blind, phase 2 study.

BACKGROUND: Targeted inhibition of the PD-L1-PD-1 pathway might be further amplified through combination of PD-1 or PD-L1 inhibitors with novel anti-TIGIT inhibitory immune checkpoint agents, such as tiragolumab. In the CITYSCAPE trial, we aimed to assess the preliminary efficacy and safety of tiragolumab plus atezolizumab (anti-PD-L1) therapy as first-line treatment for non-small-cell lung cancer (NSCLC). METHODS: CITYSCAPE is a phase 2, randomised, double-blind, placebo-controlled trial. Patients with chemotherapy-naive, PD-L1-positive (defined as a tumour proportion score of ≥1% by 22C3 immunohistochemistry pharmDx assay; Dako, Agilent Technologies, Santa Clara, CA, USA) recurrent or metastatic NSCLC with measurable disease, Eastern Cooperative Oncology Group performance status of 0 or 1, and no EGFR or ALK alterations were enrolled from 41 clinics in Europe, Asia, and the USA. Patients were randomly assigned (1:1), via an interactive voice or web-based response system, to receive tiragolumab (600 mg) plus atezolizumab (1200 mg) or placebo plus atezolizumab intravenously once every 3 weeks. Investigators and patients were masked to treatment assignment. The co-primary endpoints were investigator-assessed objective response rate and progression-free survival as per Response Evaluation Criteria in Solid Tumors version 1.1 in the intention-to-treat population, analysed after approximately 80 progression-free survival events had been observed in the primary population. Safety was assessed in all patients who received at least one dose of study drug. This trial is registered with ClinicalTrials.gov, NCT03563716, and is ongoing. FINDINGS: Patients were enrolled between Aug 10, 2018, and March 20, 2019. At data cutoff for the primary analysis (June 30, 2019), 135 of 275 patients assessed for eligibility were randomly assigned to receive tiragolumab plus atezolizumab (67 [50%]) or placebo plus atezolizumab (68 [50%]). In this primary analysis, after a median follow-up of 5·9 months (4·6-7·6, in the intention-to-treat population, 21 patients (31·3% [95% CI 19·5-43·2]) in the tiragolumab plus atezolizumab group versus 11 patients (16·2% [6·7-25·7]) in the placebo plus atezolizumab group had an objective response (p=0·031). Median progression-free survival was 5·4 months (95% CI 4·2-not estimable) in the tiragolumab plus atezolizumab group versus 3·6 months (2·7-4·4) in the placebo plus atezolizumab group (stratified hazard ratio 0·57 [95% CI 0·37-0·90], p=0·015). 14 (21%) patients receiving tiragolumab plus atezolizumab and 12 (18%) patients receiving placebo plus atezolizumab had serious treatment-related adverse events. The most frequently reported grade 3 or worse treatment-related adverse event was lipase increase (in six [9%] patients in the tiragolumab plus atezolizumab group vs two [3%] in the placebo plus atezolizumab group). Two treatment-related deaths (of pyrexia and infection) occurred in the tiragolumab plus atezolizumab group. INTERPRETATION: Tiragolumab plus atezolizumab showed a clinically meaningful improvement in objective response rate and progression-free survival compared with placebo plus atezolizumab in patients with chemotherapy-naive, PD-L1-positive, recurrent or metastatic NSCLC. Tiragolumab plus atezolizumab was well tolerated, with a safety profile generally similar to that of atezolizumab alone. These findings demonstrate that tiragolumab plus atezolizumab is a promising immunotherapy combination for the treatment of previously untreated, locally advanced unresectable or metastatic NSCLC. FUNDING: F Hoffmann-La Roche and Genentech.

Preclinical and translational pharmacology of afucosylated anti-CCR8 antibody for depletion of tumour-infiltrating regulatory T cells.

BACKGROUND AND PURPOSE: RO7502175 is an afucosylated antibody designed to eliminate C-C motif chemokine receptor 8 (CCR8)+ Treg cells in the tumour microenvironment through enhanced antibody-dependent cellular cytotoxicity (ADCC). EXPERIMENTAL APPROACH: We report findings from preclinical studies characterizing pharmacology, pharmacokinetics (PK)/pharmacodynamics (PD) and safety profile of RO7502175 and discuss the translational PK/PD approach used to inform first-in-human (FiH) dosing strategy and clinical development in solid tumour indications. KEY RESULTS: RO7502175 demonstrated selective ADCC against human CCR8+ Treg cells from dissociated tumours in vitro. In cynomolgus monkeys, RO7502175 exhibited a biphasic concentration-time profile consistent with immunoglobulin G1 (IgG1) antibodies, reduced CCR8+ Treg cells in the blood, induced minimal and transient cytokine secretion, and was well tolerated with a no-observed-adverse-effect level (NOAEL) of 100 mg·kg-1. Moreover, RO7502175 caused minimal cytokine release from peripheral blood mononuclear cells (PBMCs) in vitro. A quantitative model was developed to capture surrogate anti-murine CCR8 antibody PK/PD and tumour dynamics in mice and RO7502175 PK/PD in cynomolgus monkeys. Subsequently, the model was used to project RO7502175 human PK and receptor occupancy (RO) in patients. Because traditional approaches resulted in a low FiH dose for this molecule, even with its superior preclinical safety profile, an integrated approach based on the totality of preclinical data and modelling insights was used for starting dose selection. CONCLUSION AND IMPLICATIONS: This work demonstrates a translational research strategy for collecting and utilizing relevant nonclinical data, developing a mechanistic PK/PD model and using a comprehensive approach to inform clinical study design for RO7502175.

Implementation of a cloud-based electronic patient-reported outcome (ePRO) platform in patients with advanced cancer.

BACKGROUND: Patient reported outcomes (PROs) have been associated with improved symptom management and quality of life in patients with cancer. However, the implementation of PROs in an academic clinical practice has not been thoroughly described. Here we report on the execution, feasibility and healthcare utilization outcomes of an electronic PRO (ePRO) application for cancer patients at an academic medical center. METHODS: We conducted a randomized trial comparing an experimental ePRO arm to standard of care in patients with advanced cancer in the thoracic, gastrointestinal, and genitourinary oncology groups at Stanford Cancer Center from March 2018 to November 2019. We describe the pre-implementation, implementation, and post-implementation phases of the ePRO arm, technological barriers, electronic health record (EHR) integration, clinician burden, and patient data privacy and security. Feasibility was pre-specified to be at least 70% completion of all questionnaires. Acceptability was based on patient and clinician feedback. Ambulatory healthcare utilization was assessed by reviewing numbers of phone messages, electronic portal messages, and referrals for supportive care. RESULTS: Of 617 ePRO questionnaires sent to 72 patients, 445 (72%) were completed. Most clinicians (87.5%) and patients (93%) felt neutral or positive about the ePRO tool's ease of use. Exposure to ePRO did not cause a measurable change in ambulatory healthcare utilization, with a median of less than two phone messages and supportive care referrals, and 5-6 portal messages. CONCLUSIONS: Web-based ePRO tools for patients with advanced cancer are feasible and acceptable without increasing clinical burden. Key lessons include the importance of pilot testing, engagement of stakeholders at all levels, and the need for customization by disease group. Future directions for this work include completion of EHR integration, expansion to other centers, and development of integrated workflows for routine clinical practice.

Single-cell transcriptional diversity is a hallmark of developmental potential.

Single-cell RNA sequencing (scRNA-seq) is a powerful approach for reconstructing cellular differentiation trajectories. However, inferring both the state and direction of differentiation is challenging. Here, we demonstrate a simple, yet robust, determinant of developmental potential-the number of expressed genes per cell-and leverage this measure of transcriptional diversity to develop a computational framework (CytoTRACE) for predicting differentiation states from scRNA-seq data. When applied to diverse tissue types and organisms, CytoTRACE outperformed previous methods and nearly 19,000 annotated gene sets for resolving 52 experimentally determined developmental trajectories. Additionally, it facilitated the identification of quiescent stem cells and revealed genes that contribute to breast tumorigenesis. This study thus establishes a key RNA-based feature of developmental potential and a platform for delineation of cellular hierarchies.

Molecular characterization of a B-ring unsaturated estrogen: implications for conjugated equine estrogen components of premarin.

Conjugated equine estrogens (CEEs) are routinely used for hormone replacement therapy (HRT), making it important to understand the activities of individual estrogenic components. Although 17beta-estradiol (17beta-E2), the most potent estrogen in CEE, has been extensively characterized, the actions of nine additional less potent estrogens are not well understood. Structural differences between CEEs and 17beta-E2 result in altered interactions with the two estrogen receptors (ERalpha and ERbeta) and different biological activities. To better understand these interactions, we have determined the crystal structure of the CEE analog, 17beta-methyl-17alpha-dihydroequilenin (NCI 122), in complex with the ERalpha ligand-binding domain and a peptide from the glucocorticoid receptor-interacting protein 1 (GRIP1) coactivator. NCI 122 has chemical properties, including an unsaturated B-ring and 17alpha-hydroxyl group, which are shared with some of the estrogens found in CEEs. Structural analysis of the NCI 122-ERalpha LBD-GRIP1 complex, combined with biochemical and cell-based comparisons of CEE components, suggests that factors such as decreased ligand flexibility, decreased ligand hydrophobicity and loss of a hydrogen bond between the 17-hydroxyl group and His524, contribute significantly to the reduced potency of CEEs on ERalpha.

Role of epithelial to mesenchymal transition associated genes in mammary gland regeneration and breast tumorigenesis.

Previous studies have proposed that epithelial to mesenchymal transition (EMT) in breast cancer cells regulates metastasis, stem cell properties and chemo-resistance; most studies were based on in vitro culture of cell lines and mouse transgenic cancer models. However, the identity and function of cells expressing EMT-associated genes in normal murine mammary gland homeostasis and human breast cancer still remains under debate. Using in vivo lineage tracing and triple negative breast cancer (TNBC) patient derived xenografts we demonstrate that the repopulating capacity in normal mammary epithelial cells and tumorigenic capacity in TNBC is independent of expression of EMT-associated genes. In breast cancer, while a subset of cells with epithelial and mesenchymal phenotypes have stem cell activity, in many cells that have lost epithelial characteristics with increased expression of mesenchymal genes, have decreased tumor-initiating capacity and plasticity. These findings have implications for the development of effective therapeutic agents targeting tumor-initiating cells.

Cryptococcal osteomyelitis and meningitis in a patient with non-hodgkin's lymphoma treated with PEP-C.

The authors present the first case report of a patient with lymphoma who developed disseminated cryptococcal osteomyelitis and meningitis while being treated with the PEP-C (prednisone, etoposide, procarbazine and cyclophosphamide) chemotherapy regimen. During investigation of fever and new bony lesions, fungal culture from a rib biopsy revealed that the patient had cryptococcal osteomyelitis. Further evaluation demonstrated concurrent cryptococcal meningitis. The patient's disseminated cryptococcal infections completely resolved after a full course of antifungal treatment. Cryptococcal osteomyelitis is itself an extremely rare diagnosis, and the unique presentation with concurrent cryptococcal meningitis in our patient with lymphoma was likely due to his PEP-C treatment. It is well recognised that prolonged intensive chemotherapeutic regimens place patients at risk for atypical infections; yet physicians should recognise that even chronic low-dose therapies can put patients at risk for fungal infections. Physicians should consider fungal infections as part of the infectious investigation of a lymphopaenic patient on PEP-C.

Identification of ligands with bicyclic scaffolds provides insights into mechanisms of estrogen receptor subtype selectivity.

Estrogen receptors alpha (ERalpha) and beta (ERbeta) have distinct functions and differential expression in certain tissues. These differences have stimulated the search for subtype-selective ligands. Therapeutically, such ligands offer the potential to target specific tissues or pathways regulated by one receptor subtype without affecting the other. As reagents, they can be utilized to probe the physiological functions of the ER subtypes to provide information complementary to that obtained from knock-out animals. A fluorescence resonance energy transfer-based assay was used to screen a 10,000-compound chemical library for ER agonists. From the screen, we identified a family of ERbeta-selective agonists whose members contain bulky oxabicyclic scaffolds in place of the planar scaffolds common to most ER ligands. These agonists are 10-50-fold selective for ERbeta in competitive binding assays and up to 60-fold selective in transactivation assays. The weak uterotrophic activity of these ligands in immature rats and their ability to stimulate expression of an ERbeta regulated gene in human U2OS osteosarcoma cells provides more physiological evidence of their ERbeta-selective nature. To provide insight into the molecular mechanisms of their activity and selectivity, we determined the crystal structures of the ERalpha ligand-binding domain (LBD) and a peptide from the glucocorticoid receptor-interacting protein 1 (GRIP1) coactivator complexed with the ligands OBCP-3M, OBCP-2M, and OBCP-1M. These structures illustrate how the bicyclic scaffolds of these ligands are accommodated in the flexible ligand-binding pocket of ER. A comparison of these structures with existing ER structures suggests that the ERbeta selectivity of OBCP ligands can be attributed to a combination of their interactions with Met-336 in ERbeta and Met-421 in ERalpha. These bicyclic ligands show promise as lead compounds that can target ERbeta. In addition, our understanding of the molecular determinants of their subtype selectivity provides a useful starting point for developing other ER modulators belonging to this relatively new structural class.