Combining Desferriferrioxamine B and 1-Hydroxy-2-Piperidone ((PIPO)H) to Chelate Zirconium. Solution Structure of a Model Complex of the [89Zr]Zr-DFOcyclo*-mAb Radioimmunoconjugate

89Zr-immunoPET is a hot topic as 89Zr cumulates the advantages of 64Cu and 124I without their drawbacks. We report the synthesis of a model ligand of a chiral bioconjugable tetrahydroxamic chelator combining the desferriferrioxamine B siderophore and 1-hydroxy-2-piperidone ((PIPO)H), a chiral cyclic hydroxamic acid derivative, and the study by NMR spectroscopy of its zirconium complex. Nuclear Overhauser effect measurements (ROESY) indicated that the complex exists in the form of two diastereomers, in 77 : 23 ratio, resulting from the combination of the central chiralities at the 3-C of the (PIPO)H component and at the Zr4+ cation. The 44 lowest energy structures out of more than 1000 configurations/conformations returned by calculations based on density functional theory were examined. Comparison of the ROESY data and the calculated interatomic H⋅⋅⋅H distances allowed us to select the most probable configuration and conformations of the major complex.

Cyclotribenzylene alkynylgold(I) phosphine complexes: synthesis, chirality, and exchange of phosphine

Two different alkynyl-substituted C3-symmetric cyclotribenzylenes (CTB) were synthesized in racemic and enantiomerically pure forms, and six gold(I) phosphine complexes differing by the nature of the CTB and the phosphine were prepared and characterized, in particular by NMR spectroscopy, DOSY, electronic circular dichroism (ECD), and electrospray ionization mass spectrometry (ESI-MS). Their ECD patterns depended on the substitution of the starting CTBs and were shifted bathochromically by comparison with the latter. ESI-MS in the presence of HCO2H allowed us to detect the complexes as proton adducts. The intensities of the signals were stronger when the phosphine was more electron-rich. This technique was also used to investigate the exchange of phosphine betweeen pairs of CTB complexes. The scrambling reaction was demonstrated by the higher intensity of the signals of the complexes subjected to the exchange of a single phosphine ligand by comparison with the intensity of the signals of the starting complexes.

The ecto-enzyme CD38 modulates CD4 T cell immunometabolic responses and participates in HIV pathogenesis

Despite abundant evidence correlating T cell CD38 expression and HIV infection pathogenesis, its role as a CD4 T cell immunometabolic regulator remains unclear. We find that CD38's extracellular glycohydrolase activity restricts metabolic reprogramming after TCR-engaging stimulation in Jurkat T CD4 cells, together with functional responses, while reducing intracellular NAD and NMN concentrations. Selective elimination of CD38's ectoenzyme function licenses them to decrease the OCR/ECAR ratio upon TCR signaling and to increase cycling, proliferation, survival, and CD40L induction. Pharmacological inhibition of ectoCD38 catalytic activity in memory CD4 T cells from chronic HIV-infected patients rescued TCR-triggered responses, including differentiation and effector functions, while reverting abnormally increased basal glycolysis, cycling, and spontaneous pro-inflammatory cytokine production. Additionally, ecto-CD38 blockage normalized basal and TCR-induced mitochondrial morpho-functionality, while increasing respiratory capacity in cells from HIV+ patients and healthy individuals. Ectoenzyme CD38's immunometabolic restriction of TCR-involving stimulation is relevant to CD4 T cell biology and to the deleterious effects of CD38 overexpression in HIV disease.

Overall survival from tebentafusp versus nivolumab plus ipilimumab in first-line metastatic uveal melanoma: a propensity score-weighted analysis

BACKGROUND

Tebentafusp demonstrated a superior overall survival (OS) benefit [hazard ratio (HR) 0.51] compared to investigator's choice (82% pembrolizumab) in a randomized, phase III trial (IMCgp100-202; N = 378) in untreated metastatic uveal melanoma (mUM). The 1-year OS rates for tebentafusp and pembrolizumab were 73% and 59%, respectively. In the single-arm GEM1402 (N = 52), the 1-year OS rate for nivolumab plus ipilimumab (N+I) in mUM was 52%. Due to limitations in conducting randomized trials in mUM, we compared OS on tebentafusp or pembrolizumab (IMCgp100-202) to N+I (GEM1402) in untreated mUM using propensity scoring methods.

PATIENTS AND METHODS

Analyses were adjusted using propensity score-based inverse probability of treatment weighting (IPTW), balancing age, sex, baseline lactate dehydrogenase (LDH), baseline alkaline phosphatase, disease location, Eastern Cooperative Oncology Group status, and time from primary diagnosis to metastasis. OS was assessed using IPT-weighted Kaplan-Meier and Cox proportional hazard models. Sensitivity analyses using alternative missing data and weights methods were conducted.

RESULTS

The primary IPTW analysis included 240 of 252 patients randomized to tebentafusp from IMCgp100-202 and 45 of 52 N+I-treated patients from GEM-1402. Key baseline covariates, including LDH, were generally well balanced before weighting. The IPTW-adjusted OS favored tebentafusp, HR 0.52 [95% confidence interval (CI) 0.35-0.78]; 1-year OS was 73% for tebentafusp versus 50% for N+I. Sensitivity analyses showed consistent superior OS for tebentafusp with all IPTW HRs ≤0.61. IPTW analysis of pembrolizumab versus N+I showed no significant difference in OS (HR 0.72; 95% CI 0.50-1.06).

CONCLUSIONS

Tebentafusp was previously shown to provide an OS benefit compared to checkpoint inhibitors or chemotherapy in untreated mUM. Propensity score analysis demonstrated a similar OS benefit for tebentafusp compared with N+I. These data further support tebentafusp as the standard of care in previously untreated human leukocyte antigen (HLA)-A∗02:01+ adult patients with mUM.

First-Line Ipatasertib, Atezolizumab, and Taxane Triplet for Metastatic Triple-Negative Breast Cancer: Clinical and Biomarker Results

PURPOSE

To evaluate a triplet regimen combining immune checkpoint blockade, AKT pathway inhibition, and (nab-) paclitaxel as first-line therapy for locally advanced/metastatic triple-negative breast cancer (mTNBC).

PATIENTS AND METHODS

The single-arm CO40151 phase Ib study (NCT03800836), the single-arm signal-seeking cohort of IPATunity130 (NCT03337724), and the randomized phase III IPATunity170 trial (NCT04177108) enrolled patients with previously untreated mTNBC. Triplet therapy comprised intravenous atezolizumab 840 mg (days 1 and 15), oral ipatasertib 400 mg/day (days 1-21), and intravenous paclitaxel 80 mg/m2 (or nab-paclitaxel 100 mg/m2; days 1, 8, and 15) every 28 days. Exploratory translational research aimed to elucidate mechanisms and molecular markers of sensitivity and resistance.

RESULTS

Among 317 patients treated with the triplet, efficacy ranged across studies as follows: median progression-free survival (PFS) 5.4 to 7.4 months, objective response rate 44% to 63%, median duration of response 5.6 to 11.1 months, and median overall survival 15.7 to 28.3 months. The safety profile was consistent with the known toxicities of each agent. Grade ≥3 adverse events were more frequent with the triplet than with doublets or single-agent paclitaxel. Patients with PFS >10 months were characterized by NF1, CCND3, and PIK3CA alterations and increased immune pathway activity. PFS <5 months was associated with CDKN2A/CDKN2B/MTAP alterations and lower predicted phosphorylated AKT-S473 levels.

CONCLUSIONS

In patients with mTNBC receiving an ipatasertib/atezolizumab/taxane triplet regimen, molecular characteristics may identify those with particularly favorable or unfavorable outcomes, potentially guiding future research efforts.

Different outcomes among patients with intermediate-risk metastastic renal cell carcinoma treated with first-line tyrosine-kinase inhibitors

INTRODUCTION

Systemic therapy of patients with metastatic renal cell carcinoma (mRCC) has improved in the past years, with the advent of new immunotherapy-based combinations as a standard treatment option for first-line therapy. Nevertheless, particularly in good-risk patients by IMDC criteria, tyrosine-kinase inhibitors (TKI) may remain as an option for some patients. We reviewed our experience with TKI as first-line therapy for mRCC patients, trying to identify subgroups of patients that may still benefit from this strategy.

MATERIAL AND METHODS

All patients with mRCC treated with first-line TKI, and adequate follow-up, in University Hospital La Paz (Madrid, Spain) between 2007 and 2020 were analyzed. Patients treated inside a clinical trial were excluded from this analysis.

RESULTS

A total of 90 patients treated with first-line TKI were included. Regarding IMDC criteria, 33 patients (36.7%) were good-risk, 41 patients (45.5%) intermediate-risk, and 16 patients (17.8%) poor-risk. With a median follow-up of 49 months, the median overall survival (OS) for good, intermediate, and poor-risk patients was 54, 24, and 16 months (p = 0.004). When intermediate-risk was divided into patients with 1 or 2 risk factors, differences in OS were also statistically significant: patients with 1 risk factor had a median OS of 33 months, while patients with 2 risk factors had a median OS of 16 months, the same as poor-risk patients (p = 0.003). In the multivariate analysis, trying to find out which of the IMDC factors had a more remarkable weight in the prognosis of the patients, both ECOG and hemoglobin levels by themselves were significantly associated with OS.

CONCLUSION

In our group of patients, survival outcomes were different among patients with intermediate-risk with 1 or 2 risk factors by IMDC criteria. These could help select patients that may benefit from first-line treatment with a TKI, particularly in settings with difficult access to novel therapies, such as immunotherapy-based combinations.

Efficacy of second and third lines of treatment in advanced soft tissue sarcomas: a real-world study

BACKGROUND

Soft tissue sarcomas (STSs) are an uncommon and heterogeneous group of tumours. Several drugs and combinations have been used in clinical practice as second-line (2L) and third-line (3L) treatment. The growth modulation index (GMI) has previously been used as an exploratory efficacy endpoint of drug activity and represents an intra-patient comparison.

METHODS

We performed a real-world retrospective study including all patients with advanced STS who had received at least 2 different lines of treatment for advanced disease between 2010 and 2020 at a single institution. The objective was to study the efficacy of both 2L and 3L treatments, analysing the time to progression (TTP) and the GMI (defined as the ratio of TTP between 2 consecutive lines of therapy).

RESULTS

Eighty-one patients were included. The median TTP after 2L and 3L treatment was 3.16 and 3.06 months, and the median GMI was 0.81 and 0.74, respectively. The regimens most frequently used in both treatments were trabectedin, gemcitabine-dacarbazine, gemcitabine-docetaxel, pazopanib and ifosfamide. The median TTP by each of these regimens was 2.80, 2.23, 2.83, 4.10, and 5.00 months, and the median GMI was 0.78, 0.73, 0.67, 1.08, and 0.94, respectively. In terms of histotype, we highlight the activity (GMI > 1.33) of gemcitabine-dacarbazine in undifferentiated pleomorphic sarcoma (UPS) and in leiomyosarcoma, pazopanib in UPS, and ifosfamide in synovial sarcoma.

CONCLUSIONS

In our cohort, regimens commonly used after first-line STS treatment showed only slight differences in efficacy, although we found significant activity of specific regimens by histotype.

Carborane-based heteromolecular extended networks driven by directional C-Te⋯N chalcogen bonding interactions

We demonstrate that o-closo-(TeMe)2carborane directs, in the presence of linear ditopic neutral Lewis bases, the formation of co-crystals with 1D extended supramolecular networks. Specifically, the network formation is systematically stabilized by short and quasi-linear C-Te⋯N chalcogen-bonding (ChB) interactions. In sum, we report efficient carborane-based tectons to rationally design high-dimensional neutral heteromolecular networks.

Adjuvant dabrafenib and trametinib for patients with resected BRAF -mutated melanoma: DESCRIBE-AD real-world retrospective observational study

BRAF and MEK inhibitor, dabrafenib plus trametinib, adjuvant therapy is effective for high-risk resected melanoma patients with BRAF - V600 mutations. However, real-world evidence is limited. We aimed to determine the feasibility of this therapy in routine clinical practice. DESCRIBE-AD, a retrospective observational study, collected real-world data from 25 hospitals in Spain. Histologically confirmed and resected BRAF -mutated melanoma patients aged ≥18 years who were previously treated with dabrafenib plus trametinib adjuvant therapy, were included. The primary objectives were treatment discontinuation rate and time to discontinuation. The secondary objectives included safety and efficacy. From October 2020 to March 2021, 65 patients were included. Dabrafenib and trametinib discontinuation rate due to treatment-related adverse events (TRAEs) of any grade was 9%. Other reasons for discontinuation included patients' decisions (6%), physician decisions (6%), unrelated adverse events (3%), disease progression (5%), and others (5%). The median time to treatment discontinuation was 9 months [95% confidence interval (CI), 5-11]. G3-4 TRAEs occurred in 21.5% of patients, the most common being pyrexia (3%), asthenia (3%), and diarrhoea (3%). Unscheduled hospitalisations and clinical tests occurred in 6 and 22% of patients, respectively. After 20-month median follow-up (95% CI, 18-22), 9% of patients had exitus due to disease progression, with a 12-month relapse-free survival and overall survival rates of 95.3% and 100%, respectively. Dabrafenib and trametinib adjuvant therapy proved effective for melanoma patients in a real-world setting, with a manageable toxicity profile. Toxicity frequencies were low leading to low incidence of unscheduled medical visits, tests, and treatment discontinuations.

Predicting Risk of Severe Toxicity and Early Death in Older Adult Patients Treated with Chemotherapy

BACKGROUND

Determining the risk of grade 3-5 toxicity and early death (ED) is important to plan chemotherapy in older adult patients with cancer. Our objective was to identify factors predicting these complications at the time of treatment initiation.

METHODS

234 patients aged ≥70 were subjected to a geriatric assessment and variables related to the tumor and the treatment were also collected. Logistic regression multivariable analysis was used to relate these factors with the appearance of grade 3-5 toxicity and ED. Predictive scores for both toxicity and ED were then developed.

RESULTS

Factors related to grade 3-5 toxicity were hemoglobin, MAX2 index, ADL, and the CONUT score. Factors related to ED were tumor stage and the GNRI score. Two predictive scores were developed using these variables. ROC curves for the prediction of toxicity and ED were 0.71 (95% CI: 0.64-0.78) and 0.73 (95% CI: 0.68-0.79), respectively.

CONCLUSIONS

Two simple and reliable scores were developed to predict grade 3-5 toxicity and ED in older adult patients with cancer. This may be helpful in treatment planning.

Multi-omics Characterization of Response to PD-1 Inhibitors in Advanced Melanoma

Immunotherapy improves the survival of patients with advanced melanoma, 40% of whom become long-term responders. However, not all patients respond to immunotherapy. Further knowledge of the processes involved in the response and resistance to immunotherapy is still needed. In this study, clinical paraffin samples from fifty-two advanced melanoma patients treated with anti-PD-1 inhibitors were assessed via high-throughput proteomics and RNA-seq. The obtained proteomics and transcriptomics data were analyzed using multi-omics network analyses based on probabilistic graphical models to identify those biological processes involved in the response to immunotherapy. Additionally, proteins related to overall survival were studied. The activity of the node formed by the proteins involved in protein processing in the endoplasmic reticulum and antigen presentation machinery was higher in responders compared to non-responders; the activity of the immune and inflammatory response node was also higher in those with complete or partial responses. A predictor for overall survival based on two proteins (AMBP and PDSM5) was defined. In summary, the response to anti-PD-1 therapy in advanced melanoma is related to protein processing in the endoplasmic reticulum, and also to genes involved in the immune and inflammatory responses. Finally, a two-protein predictor can define survival in advanced disease. The molecular characterization of the mechanisms involved in the response and resistance to immunotherapy in melanoma leads the way to establishing therapeutic alternatives for patients who will not respond to this treatment.

Metabolomics unravels subtype-specific characteristics related to neoadjuvant therapy response in breast cancer patients

INTRODUCTION

Breast cancer is the most diagnosed tumor and the leading cause of cancer death in women worldwide. Metabolomics allows the quantification of the entire set of metabolites in blood samples, making it possible to study differential metabolomics patterns related to neoadjuvant treatment in the breast cancer neoadjuvant setting.

OBJECTIVES

Characterizing metabolic differences in breast cancer blood samples according to their response to neoadjuvant treatment.

METHODS

One hundred and three plasma samples of breast cancer patients, before receiving neoadjuvant treatment, were analyzed through UPLC-MS/MS metabolomics. Then, metabolomics data were analyzed using probabilistic graphical models and biostatistics methods.

RESULTS

Metabolomics data allowed the identification of differences between groups according to response to neoadjuvant treatment. These differences were specific to each breast cancer subtype. Patients with HER2+ tumors showed differences in metabolites related to amino acids and carbohydrates pathways between the two pathological response groups. However, patients with triple-negative tumors showed differences in metabolites related to the long-chain fatty acids pathway. Patients with Luminal B tumors showed differences in metabolites related to acylcarnitine pathways.

CONCLUSIONS

It is possible to identify differential metabolomics patterns between complete and partial responses to neoadjuvant therapy, being this metabolomic profile specific for each breast cancer subtype.

Impacts of plasma microbial lipopolysaccharide translocation on B cell perturbations and anti-CD4 autoantibody production in people with HIV on suppressive antiretroviral therapy

BACKGROUND

. Up to 20% of people with HIV (PWH) who undergo virologically suppressed antiretroviral therapy (ART) fail to experience complete immune restoration. We recently reported that plasma anti-CD4 IgG (antiCD4IgG) autoantibodies from immune non-responders specifically deplete CD4 + T cells via antibody-dependent cytotoxicity. However, the mechanism of antiCD4IgG production remains unclear.

METHODS

. Blood samples were collected from 16 healthy individuals and 25 PWH on suppressive ART. IgG subclass, plasma lipopolysaccharide (LPS), and antiCD4IgG levels were measured by ELISA. Gene profiles in B cells were analyzed by microarray and quantitative PCR. Furthermore, a patient-derived antiCD4IgG-producing B cell line was generated and stimulated with LPS in vitro. B cell IgG class switch recombination (CSR) was evaluated in response to LPS in splenic B cells from C57/B6 mice in vitro.

RESULTS

. Increased plasma anti-CD4 IgGs in PWH were predominantly IgG1 and associated with increased plasma LPS levels as well as B cell expression of TLR2, TLR4, and MyD88 mRNA in vivo. Furthermore, LPS stimulation induced antiCD4IgG production in the antiCD4IgG B cell line in vitro. Finally, LPS promoted CSR in vitro.

CONCLUSION

. Our findings suggest that persistent LPS translocation may promote anti-CD4 autoreactive B cell activation and antiCD4IgG production in PWH on ART, which may contribute to gradual CD4 + T cell depletion. This study suggests that reversing a compromised mucosal barrier could improve ART outcomes in PWH who fail to experience complete immune restoration.

Palbociclib Rechallenge for Hormone Receptor-Positive/HER-Negative Advanced Breast Cancer: Findings from the Phase II BioPER Trial

PURPOSE

To assess the efficacy and exploratory biomarkers of continuing palbociclib plus endocrine therapy (ET) beyond progression on prior palbociclib-based regimen in patients with hormone receptor-positive/HER2-negative (HR+/HER2-) advanced breast cancer (ABC).

PATIENTS AND METHODS

The multicenter, open-label, phase II BioPER trial included women who had experienced a progressive disease (PD) after having achieved clinical benefit on the immediately prior palbociclib plus ET regimen. Palbociclib (125 mg, 100 mg, or 75 mg daily orally for 3 weeks and 1 week off as per prior palbociclib-based regimen) plus ET of physician's choice were administered in 4-week cycles until PD or unacceptable toxicity. Coprimary endpoints were clinical benefit rate (CBR) and percentage of tumors with baseline loss of retinoblastoma (Rb) protein expression. Additional endpoints included safety and biomarker analysis.

RESULTS

Among 33 patients enrolled, CBR was 34.4% [95% confidence interval (CI), 18.6-53.2; P < 0.001] and 13.0% of tumors (95% CI, 5.2-27.5) showed loss of Rb protein expression, meeting both coprimary endpoints. Median progression-free survival was 2.6 months (95% CI, 1.8-6.7). No new safety signals were reported. A signature that included baseline mediators of therapeutic resistance to palbociclib and ET (low Rb score, high cyclin E1 score, ESR1 mutation) was independently associated with shorter median progression-free survival (HR, 22.0; 95% CI, 1.71-282.9; P = 0.018).

CONCLUSIONS

Maintaining palbociclib after progression on prior palbociclib-based regimen seems to be a reasonable, investigational approach for selected patients. A composite biomarker signature predicts a subset of patients who may not derive a greater benefit from palbociclib rechallenge, warranting further validation in larger randomized controlled trials.

Proteomics Characterization of Clear Cell Renal Cell Carcinoma

PURPOSE

To explore the tumor proteome of patients diagnosed with localized clear cell renal cancer (ccRCC) and treated with surgery.

MATERIAL AND METHODS

A total of 165 FFPE tumor samples from patients diagnosed with ccRCC were analyzed using DIA-proteomics. Proteomics ccRCC subtypes were defined using a consensus cluster algorithm (CCA) and characterized by a functional approach using probabilistic graphical models and survival analyses.

RESULTS

We identified and quantified 3091 proteins, including 2026 high-confidence proteins. Two proteomics subtypes of ccRCC (CC1 and CC2) were identified by CC using the high-confidence proteins only. Characterization of molecular differences between CC1 and CC2 was performed in two steps. First, we defined 514 proteins showing differential expression between the two subtypes using a significance analysis of microarrays analysis. Proteins overexpressed in CC1 were mainly related to translation and ribosome, while proteins overexpressed in CC2 were mainly related to focal adhesion and membrane. Second, a functional analysis using probabilistic graphical models was performed. CC1 subtype is characterized by an increased expression of proteins related to glycolysis, mitochondria, translation, adhesion proteins related to cytoskeleton and actin, nucleosome, and spliceosome, while CC2 subtype showed higher expression of proteins involved in focal adhesion, extracellular matrix, and collagen organization.

CONCLUSIONS

ccRCC tumors can be classified in two different proteomics subtypes. CC1 and CC2 present specific proteomics profiles, reflecting alterations of different molecular pathways in each subtype. The knowledge generated in this type of studies could help in the development of new drugs targeting subtype-specific deregulated pathways.

Abstract 5416: RNA-seq and proteomics to identify response to immunotherapy in advanced melanoma: a Spanish Melanoma Group Study

Background: Prediction of response to immunotherapy remains an unmet need in the field of advanced melanoma.

Methods: Computational analyses, including probabilistic graphical models, sparse k-means, and consensus cluster, were used to characterize melanoma TCGA samples. The implication of the identified processes in response to immunotherapy was then studied in an independent cohort of 53 patients with advanced melanoma and treated with PD-1 inhibitors. Paraffin samples from this cohort were analyzed using RNA-seq and mass-spectrometry proteomics.

Results: In the TCGA cohort, there were two different layers of information: one related to molecular features of the tumor (based on keratinization, melanogenesis, and extracellular space), and one related to immune status. Therefore, two independent classifications of TCGA melanoma samples were established: molecular and immune. The immune classification distinguished between responders and not responders to immunotherapy in the second cohort (p= 0.0006, HR=6.52). Finally, high-throughput proteomics was used to characterize molecular mechanisms involved in response to immunotherapy, identifying several biological processes and proteins that may be relevant in treatment selection for patients who do not respond.

Conclusions: We established that the immune information was independent of tumor molecular features in melanomas included in the TCGA. An immune classification of these tumors was established. This immune classification predicted response to immunotherapy in a new cohort of patients with advanced melanoma treated with PD-1 inhibitors. Finally, proteomics was used to identify possible targets in those patients who did not respond to immunotherapy.

Citation Format: Lucia Trilla-Fuertes, Guillermo Prado-Vazquez, Angelo Gámez-Pozo, Rocio Lopez-Vacas, Maria Isabel Lumbreras Herrera, Virtudes Soriano, Fernando Garicano, Maria Jose Lecumberri, Maria Rodriguez, Margarita Majem, Elisabeth Perez, Maria Gonzalez-Cao, Juana Oramas, Alejandra Magdaleno, Joaquin Fra, Alfonso Martin, Monica Corral, Teresa Puertolas, Juan Angel Fresno Vara, Enrique Espinosa. RNA-seq and proteomics to identify response to immunotherapy in advanced melanoma: a Spanish Melanoma Group 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 5416.

Bio-miR: A prognostic microRNA-based signature for localized clear cell renal cell carcinoma

e16519

Background: Prognosis of localized clear cell renal cell carcinoma (ccRCC) patients is estimated by nomograms based on clinico-pathological factors. However, clinical guidelines do not recommend their use. Recently, pembrolizumab has demonstrated benefit in disease-free survival (DFS) in medium-high risk localized ccRCC, increasing the need for better patient stratification tools. In this study, we have defined and validated a molecular signature, Bio-miR, based on the expression of nine microRNAs, with prognostic value in ccRCC. Methods: The discovery and two validation cohorts (Leeds-UK and Spain) consisted of patients with resected localized (stage Ib-III) ccRCC and no adjuvant therapy. miRNA expression was analyzed using microarrays and validated using qPCR in FFPE nephrectomy tissues. Cox regression was used to define the best microRNAs combination to predict risk of relapse. Results: In the discovery cohort (n = 71), DFS at 5 years was 93.9% amongst Bio-miR-defined low-risk patients and 61.6% in high-risk patients (HR = 6.9 (3.4-42.9), p < 0.001). Cancer-specific survival at 5 years was 95.7% and 86.4% in low- and high-risk patients, respectively (HR = 7.7 (1.7-35.1), p < 0.01). Bio-miR compared favorably with different histopathological factors and UISS and Karakiewicz´s nomograms. In the Leeds validation cohort (n = 75/95 passing qPCR quality control), patients defined as low-risk had a 5-year DFS rate of 94% versus 62% in high-risk defined disease. In this cohort Bio-miR was able to divide the Leibovich intermediate-risk population into two groups with divergent five-year DFS rates (100% vs 71%). In the Spanish validation cohort (n = 180), DFS rates at 5 years were 82.9% in the low-risk group and 58.7% in the high-risk group (HR = 2.4 (1.4-4.4); p < 0.005). Applying the inclusion criteria from the phase III KEYNOTE-564 trial, Bio-miR identifies a small low-risk population who could be spared adjuvant treatment. Conversely, amongst patients excluded from the study due to low-risk features, Bio-miR defines a high-risk population (DFS at five years of 50%) who should be prioritized for adjuvant therapy. Conclusions: We define and validate a nine-microRNA based signature capable of dichotomizing patients with localized ccRCC into low- and high-risk groups based on risk of relapse. Importantly, Bio-miR acts independently of tumor stage and grade and could, therefore, help refine the selection of patients for adjuvant therapy as well as inform the design of future adjuvant ccRCC trials.

EMRseq: Registry-based outcome analysis on 1,000 patients with BRAF V600–mutated metastatic melanoma in Europe treated with either immune checkpoint or BRAF-/MEK inhibition

9540

Background: In BRAF mutated metastatic melanoma, potential outcome differences for different choices of 1st line treatments including immunotherapy or BRAF-/MEK inhibition are not completely understood. We therefore analyzed the treatment patterns and outcome of systemic therapies for patients BRAF mutated metastatic melanoma. Methods: From the EUMelaReg treatment registry, patients fulfilling the following inclusion criteria were consecutively included until a number of 1,000 evaluable cases was reached. 1) Patients with metastatic melanoma and BRAF V600 mutation 2) First line treatment with either combined BRAF-/MEK or immune checkpoint inhibition (ICI) with PD-1 single agent or combined PD-1/CTLA-4 antibodies. Multivariable cox regression analysis as well as propensity score based weighting were used to control for bias from baseline imbalances. Primary outcomes of interest were overall survival (OS) and 2nd line PFS (PFS-2), stratified for upfront treatment decision of ICI versus targeted therapy. PFS-2 was defined as the interval from start of first line treatment to a progression after a 2nd line treatment or death of any cause. Further endpoints were evaluated including time on treatment (ToT), time to next treatment and 2nd line treatments. Results: In total 529 (52.9 %) patients received BRAF/MEK-i, and 471 (47.1%) ICI. For various co-variates there were significant imbalances between strata, including number of metastatic sites, AJCC substage, serum LDH, and ECOG performance status, with more favorable prognostic variables for patients receiving immunotherapy. The ORR for BRAF/MEK-i was significantly higher than for ICI (53.3% vs. 42.0%; p=0.0004), but for OS and PFS2 the adjusted hazard ratios were significantly in favor for ICI (HR 0.62 and 0.66, respectively; p <0.0001). In 2nd line, patients switching from ICI to BRAF/MEK-i had again markedly higher ORR than patients switching vice versa (57.7% vs. 19.9%; P<0.0001), and also significantly longer unadjusted PFS (8.1 vs. 3.1 months; p <0.0001) and OS (15.7 vs. 10.6 mths; p=0.01) after start of 2nd line treatment. Conclusions: The two cohorts had imbalances on key prognosis variables. After adjustment for these imbalances, upfront ICI still resulted in significantly longer OS as compared to BRAF/MEK-i. Due to the nature of real-world observational data causing inherent imbalances in the treatments cohorts and being unable to account for potential unknown confounders, outcome may still be biased despite adjustment efforts.[Table: see text]

N-Iodosaccharin-pyridine co-crystal system under pressure: experimental evidence of reversible twinning

This work presents a single-crystal X-ray diffraction study of an organic co-crystal composed of N-iodosaccharin and pyridine (NISac·py) under hydrostatic pressure ranging from 0.00 (5) GPa to 4.5 (2) GPa. NISac·py crystallizes in the monoclinic system (space group B2₁/e). The unconventional setting of the space group is adopted (the conventional setting is P2₁/c, No. 14) to emphasise the strongly pseudo-orthorhombic symmetry of the lattice, with a β angle very close to 90°. The crystal structure contains one molecule each of N-iodosaccharin (NISac) and pyridine (py) in the asymmetric unit (Z' = 1), linked via an N_sac...I...N'_py halogen-bonding motif. A gradual modification of this motif is observed under pressure as a result of changes in the crystalline environment. Mechanical twinning is observed under compression and the sample splits into two domains, spanning an unequal volume that is mapped by a twofold rotation about the [100] direction of the B2₁/e unit cell. The twinning is particularly significant at high pressure, being reversible when the pressure is released. The structure of the twinned sample reveals the continuity of a substantial substructure across the composition plane. The presence of this common substructure in the two orientations of the twinned individuals can be interpreted as a structural reason for the formation of the twin and is the first observed example in a molecular crystal. These results indicate that the anisotropy of intermolecular interactions in the crystal structure results in an anisotropic strain generated upon the action of hydrostatic compression. Periodic density functional theory calculations were carried out by considering an isotropic external pressure, the results showing good agreement with the experimental findings. The bulk modulus of the crystal was obtained from the equations of state, being 7 (1) GPa for experimental data and 6.8 (5) GPa for theoretical data.

Probing the Electronic Properties and Interaction Landscapes in a Series of N-(Chlorophenyl)pyridinecarboxamides

A 3 × 3 isomer grid of nine N-(chlorophenyl)pyridinecarboxamides (NxxCl) is reported with physicochemical studies and single crystal structures (Nx = pyridinoyl moiety; xCl = aminochlorobenzene ring; x = para-/meta-/ortho-), as synthesized by the reaction of the substituted p-/m-/o-pyridinecarbonyl chlorides (Nx) with p-/m-/o-aminochlorobenzenes (xCl). Several of the nine NxxCl crystal structures display structural similarities with their halogenated NxxX and methylated NxxM relatives (x = p-/m-/o-substitutions; X = F, Br; M = methyl). Indeed, five of the nine NxxCl crystal structures are isomorphous with their NxxBr analogues as the NpmCl/Br, NpoCl/Br, NmoCl/NmoBr, NopCl/Br, and NooCl/Br pairs. In the NxxCl series, the favored hydrogen bonding mode is aggregation by N-H···N_pyridine interactions, though amide···amide intermolecular interactions are noted in NpoCl and NmoCl. For the NoxCl triad, intramolecular N-H···N_pyridine interactions influence molecular planarity, whereas NppCl·H₂O (as a monohydrate) exhibits O-H···O, N-H···O1W, and O1W-H···N interactions as the primary hydrogen bonding. Analysis of chlorine-containing compounds on the CSD is noted for comparisons. The interaction environments are probed using Hirshfeld surface analysis and contact enrichment studies. The melting temperatures (T _m) depend on both the lattice energy and molecular symmetry (Carnelley's rule), and the melting points can be well predicted from a linear regression of the two variables. The relationships of the T _m values with the total energy, the electrostatic component, and the strongest hydrogen bond components have been analyzed.

Synergistic effect of antimetabolic and chemotherapy drugs in triple-negative breast cancer

The triple-negative breast cancer (TNBC) subtype comprises approximately 15% of all breast cancers and is associated with poor long-term outcomes. Classical chemotherapy remains the standard of treatment, with toxicity and resistance being major limitations. TNBC is a high metabolic group, and antimetabolic drugs are effective in inhibiting TNBC cell growth. We analyzed the combined effect of chemotherapy and antimetabolic drug combinations in MDA-MB-231, MDA-MB-468 and HCC1143 human TNBC cell lines. Cells were treated with each drug or with drug combinations at a range of concentrations to establish the half-maximal inhibitory concentrations (IC₅₀). The dose-effects of each drug or drug combination were calculated, and the synergistic or antagonistic effects of drug combinations were defined. Chemotherapy and antimetabolic drugs exhibited growth inhibitory effects on TNBC cell lines. Antimetabolic drugs targeting the glycolysis pathway had a synergistic effect with chemotherapy drugs, and antiglycolysis drug combinations also had a synergistic effect. The use of these drug combinations could lead to new therapeutic strategies that reduce chemotherapy drug doses, decreasing their toxic effect, or that maintain the doses but enhance their efficacy by their synergistic effect with other drugs.

Topochemical Polymerization of a Diacetylene in a Chalcogen-Bonded (ChB) Assembly

The successful topochemical polymerization of bis(selenocyanatomethyl)butadyine 1 is achieved upon association in a 1 : 1 co-crystal with 1,2-bis(2-pyridyl)ethylene (2-bpen) through strong and linear (NC)-Se⋅⋅⋅N_Py chalcogen bonding (ChB) interactions, allowing for an appropriate parallel alignment of the diacetylene moieties toward the solid-state reaction. Co-crystal 1⋅(2-bpen) undergoes polymerization upon heating at 100 °C. The reaction progress was monitored by IR, DSC and PXRD. An enhancement of the polymer conductivity by 8 orders of magnitude is observed upon iodine doping. Strikingly, the course of polymerization is accompanied with sublimation of the ChB acceptor molecules 2-bpen, providing the polymer in a pure form with full recovery of the co-former, at variance with the usual hydrogen-bonded co-crystal strategies toward polydiacetylenes.

Cardiac monitoring during trastuzumab therapy in metastatic breast cancer: early incidence of cardiac dysfunction

Trastuzumab therapy has dramatically changed breast cancer prognosis. Consensus documents recommend a close monitoring during therapy, not always feasible, especially in metastatic breast cancer. The purpose of this study is to describe trastuzumab cardiotoxicity in metastatic breast cancer patients to understand how to improve cardiovascular monitoring. We retrospectively studied metastatic breast cancer patients scheduled for trastuzumab therapy (2001-2018). All patients underwent a baseline evaluation and monitoring during therapy. Cardiotoxicity was defined as symptomatic heart failure or asymptomatic decrease in left ventricular ejection fraction > 10% from baseline and < 53%. Ninety-two women were included, mean age 61 years (±14.43), median follow-up 42.5 months (IQR 26-74). Fourteen percent developed cardiotoxicity:  two heart failure with preserved left ventricular ejection fraction, three heart failure with reduced left ventricular ejection fraction, and eight asymptomatic decreased in left ventricular ejection fraction. Eighty-one percent of cardiac dysfunction cases occurred within the first 4 years and on median of 31 months from trastuzumab initiation. Thus, in metastatic breast cancer patients, trastuzumab-mediated cardiotoxicity occurred more frequently during the first 4 years. These data should be considered to optimize follow-up protocols.

N-chlorobenzimidazoles as efficient and structurally diverse amphoteric halogen bond donors in crystal engineering

The ability of amphoteric N-chlorobenzimidazoles to self-associate into 1D chains through strong and linear N−Cl•••N halogen bond interactions is demonstrated. Less polarisable Cl atom is strongly activated thanks to the...

Clinical and molecular response to tebentafusp in previously treated patients with metastatic uveal melanoma: a phase 2 trial

In patients with previously treated metastatic uveal melanoma, the historical 1 year overall survival rate is 37% with a median overall survival of 7.8 months. We conducted a multicenter, single-arm, open-label phase 2 study of tebentafusp, a soluble T cell receptor bispecific (gp100×CD3), in 127 patients with treatment-refractory metastatic uveal melanoma (NCT02570308). The primary endpoint was the estimation of objective response rate based on RECIST (Response Evaluation Criteria in Solid Tumours) v1.1. Secondary objectives included safety, overall survival, progression-free survival and disease control rate. All patients had at least one treatment-related adverse event, with rash (87%), pyrexia (80%) and pruritus (67%) being the most common. Toxicity was mostly mild to moderate in severity but was greatly reduced in incidence and intensity after the initial three doses. Despite a low overall response rate of 5% (95% CI: 2-10%), the 1 year overall survival rate was 62% (95% CI: 53-70%) with a median overall survival of 16.8 months (95% CI: 12.9-21.3), suggesting benefit beyond traditional radiographic-based response criteria. In an exploratory analysis, early on-treatment reduction in circulating tumour DNA was strongly associated with overall survival, even in patients with radiographic progression. Our findings indicate that tebentafusp has promising clinical activity with an acceptable safety profile in patients with previously treated metastatic uveal melanoma, and data suggesting ctDNA as an early indicator of clinical benefit from tebentafusp need confirmation in a randomized trial.

Prediction of Chemotoxicity, Unplanned Hospitalizations and Early Death in Older Patients with Colorectal Cancer Treated with Chemotherapy

Simple Summary

Chemotoxicity, unplanned hospitalizations (Uhs) and early death (ED) are common among older patients with cancer who receive chemotherapy. Our objective was to determine factors predicting these complications. A predictive score for these three complications based on geriatric, tumor and laboratory variables was developed in a series of 215 older patients with colorectal carcinoma receiving chemotherapy. The use of this score may reliably identify patients at risk to have excessive toxicity with chemotherapy, UH or ED, thus helping to plan treatment, implement adaptive measures, and intensify follow-up.

Abstract

Purpose: To identify risk factors for toxicity, unplanned hospitalization (UH) and early death (ED) in older patients with colorectal carcinoma (CRC) initiating chemotherapy. Methods: 215 patients over 70 years were prospectively included. Geriatric assessment was performed before treatment, and tumor and treatment variables were collected. The association between these factors and grade 3–5 toxicity, UH and ED (<6 months) was examined by using multivariable logistic regression. Score points were assigned to each risk factor. Results: During the first 6 months of treatment, 33% of patients developed grade 3–5 toxicity, 31% had UH and 23% died. Risk factors were, for toxicity, instrumental activities of daily living, creatinine clearance, weight loss and MAX2 index; for UH, Charlson Comorbidity Score, creatinine clearance, weight loss, serum albumin, and metastatic disease; and for ED, basic activities in daily living, weight loss, metastatic disease, and hemoglobin levels. Predictive scores were built with these variables. The areas under receiver operation characteristic (ROC) curves for toxicity, UH and ED were 0.70 (95% CI: 0.64–0.766), 0.726 (95% IC: 0.661–0.799) and 0.74 (95% IC: 0.678–0.809), respectively. Conclusion: Simple scores based on geriatric, tumor and laboratory characteristics predict severe toxicity, UH and ED, and may help in treatment planning.

Intermittent BRAF inhibition in advanced BRAF mutated melanoma results of a phase II randomized trial

Combination treatment with BRAF (BRAFi) plus MEK inhibitors (MEKi) has demonstrated survival benefit in patients with advanced melanoma harboring activating BRAF mutations. Previous preclinical studies suggested that an intermittent dosing of these drugs could delay the emergence of resistance. Contrary to expectations, the first published phase 2 randomized study comparing continuous versus intermittent schedule of dabrafenib (BRAFi) plus trametinib (MEKi) demonstrated a detrimental effect of the “on−off” schedule. Here we report confirmatory data from the Phase II randomized open-label clinical trial comparing the antitumoral activity of the standard schedule versus an intermittent combination of vemurafenib (BRAFi) plus cobimetinib (MEKi) in advanced BRAF mutant melanoma patients (NCT02583516). The trial did not meet its primary endpoint of progression free survival (PFS) improvement. Our results show that the antitumor activity of the experimental intermittent schedule of vemurafenib plus cobimetinib is not superior to the standard continuous schedule. Detection of BRAF mutation in cell free tumor DNA has prognostic value for survival and its dynamics has an excellent correlation with clinical response, but not with progression. NGS analysis demonstrated de novo mutations in resistant cases.

Whether intermittent strategies of delivering drugs can improve cancer patients survival is still unclear. Here, the authors reports the results of a randomized phase II clinical trial aimed to compare the efficacy and safety of two dosing regimens (continuous and intermittent) of vemurafenib and cobimetinib combination as first-line treatment of patients with unresectable or metastatic advanced melanoma with BRAFV600 mutation

538 Updated survival of patients with previously treated metastatic uveal melanoma who received tebentafusp

Background

Tebentafusp, a bispecific fusion protein consisting of an affinity-enhanced T cell receptor fused to an anti-CD3 effector that can redirect T cells to target gp100+ cells, has shown an overall survival benefit for patients with untreated metastatic uveal melanoma (mUM) in a Ph3 trial (NCT03070392). Metastatic uveal melanoma (mUM) is a historically treatment-refractory tumor with 1-year (yr), 2-yr and 3-yr OS rates of 37%, 15% and 9%, respectively, and median OS of 7.8 months in 2L+ patients.1 In the primary analysis of the phase 2 IMCgp100–102 study (NCT02570308) enrolling patients with previously treated mUM, the 1-year overall survival (OS) rate was 62% with median OS of 16.8 months.2 We present updated OS and safety after 2-year follow-up.

Methods

127 HLA-A*02:01+ 2L+ mUM patients were dosed weekly with tebentafusp following intra-patient dose escalation: 20mcg dose 1, 30mcg dose 2 and 68mcg dose 3+. Primary objective was ORR and secondary objectives included safety, OS and PFS. Here we present the updated OS and safety (data cut-off 31 Mar 2021).

Results

Median follow-up was 29.9 mos (range 1.8 – 59.9 mos). With extended follow-up, the 1-yr, 2-yr and 3-yr OS rates were 61%, 37% and 24%, respectively (figure 1). Median OS remained unchanged at 16.8 mos (95% CI, 12.8 – 22.5 mos).Mean and median duration of treatment were 9.5 mos and 5.6 mos (0 – 47.4 mos), respectively. As previously reported, most treatment-related AEs (TRAEs) occurred early on treatment. Beyond 6 months, no TRAE led to treatment discontinuation. No new safety signals, changes in the type or treatment-related deaths were reported. Beyond 12 months, there were a total of 7 Grade (G) 3 or 4 events in 3 (7%) patients, all were temporally related to tumor progression and majority included lab abnormalities. Episodes of rash, a common tebentafusp-related AE early on-treatment, were infrequent after 6 months, with no Grade 3 or 4 events.

Abstract 538 Figure 1

Kaplan-Meier estimate of overall survival at 2-yr follow-up of IMCgp100-102

Conclusions

This study provides the longest follow-up of OS and safety of a soluble TCR therapeutic to date. Tebentafusp continued to show promising survival for 2L+ mUM patients with estimated 2-yr OS rate of 37%. Tebentafusp’s safety profile was as expected and consistent with primary analysis showing that most adverse events occur early on treatment with incidence and severity decreasing with prolonged exposure.

Trial Registration

NCT02570308

References

Rantala ES, Hernberg M, Kivela TT. Overall survival after treatment for metastatic uveal melanoma: a systematic review and meta-analysis. Melanoma Res 2019;29:561–568.

Sacco JJ, Carvajal R, Butler MO, et al. A phase (ph) II, multi-center study of the safety and efficacy of tebentafusp (tebe) (IMCgp100) in patients (pts) with metastatic uveal melanoma (mUM). Ann Oncol 2020;31: S1442–S1143.

Ethics Approval

The institutional review board or independent ethics committee at each center approved the trial. The trial was conducted in accordance with the Declaration of Helsinki and the International Conference on Harmonization Good Clinical Practice guidelines.

Molecular characterization of triple negative breast cancer formaldehyde-fixed paraffin-embedded samples by data-independent acquisition proteomics

Triple negative breast cancer accounts for 15%-20% of all breast carcinomas and is clinically characterized by an aggressive phenotype and poor prognosis. Triple negative tumors do not benefit from targeted therapies, so further characterization is needed to define subgroups with potential therapeutic value. In this work, the proteomes of 125 formalin-fixed paraffin-embedded samples from patients diagnosed with non-metastatic triple negative breast cancer were analyzed using data-independent acquisition + in a LTQ-Orbitrap Fusion Lumos mass spectrometer coupled to an EASY-nLC 1000. 1206 proteins were identified in at least 66% of the samples. Hierarchical clustering, probabilistic graphical models and Significance Analysis of Microarrays were combined to characterize proteomics-based molecular groups. Two molecular groups were defined with differences in biological processes such as glycolysis, translation and immune response. These two molecular groups showed also several differentially expressed proteins. This clinically homogenous dataset may serve to design new therapeutic strategies in the future.

Characterization of liver function tests (LFTs) following tebentafusp (tebe) in previously treated (2L+) metastatic uveal melanoma (mUM) patients (pts)

e21513

Background: Tebe is a bispecific gp100-targeted T cell receptor fusion protein that can redirect polyclonal T cells to target gp100+ cells leading to T cell activation and release of inflammatory mediators. Hepatocytes do not express gp100 and tebe did not redirect T cells against normal hepatocytes in preclinical in vitro studies. However, since most mUM pts have liver metastases, tebe may result in secondary effects from localized tumor-related inflammation. Here we describe LFT kinetics and outcomes for pts in the IMCgp100-102 study (NCT02570308). Methods: 127 HLA-A*02:01+ pts with 2L+ mUM received tebe, administered weekly at the RP2D following intra-patient dose escalation (C1D1: 20μg; C1D8: 30μg; C1D15+: 68μg). Pts were eligible if ALT/AST ≤ 3 x ULN and bilirubin ≤ 1.5 x ULN. LFTs were measured at baseline (BL) and weekly prior to each dose using local laboratories. AE grading was based on CTCAE v4.03. This analysis was conducted on the primary analysis snapshot dated 04Jun20. Results: At BL,125/127 (98%) pts had ALT/AST ≤ grade(G)1 and 122/127 (96%) had liver metastasis. 68/127 (54%) had an increase in post-BL grade for ALT, AST or both. Of these 48/68 (71%) increased to G1, 9/68 (13%) to G2, 7/68 (10%) to G3, and 4/68 (6%) to G4. 67 of these 68 pts (99%) had liver metastasis and most had largest liver metastasis > 3cm (38 pts > 3 cm, 29 pts < 3cm and 1 pt without). ALT/AST increases occurred early in treatment in 36/68 (53%) including at Dose 1 (12/68; 18%), Dose 2 (10/68; 15%), or Dose 3 (14/68; 21%). In the other 32/68 pts (47%), ALT/AST increases occurred at or after Dose 4 (4-65), and most of these events (21/32; 66%) were associated temporally with increase in size of liver metastases. Among the 11 pts with G3/4 ALT/AST increases post-BL, most pts experienced these events early (Doses 1-3) (8/11; 73%) and in the context of either increase in size of liver metastases / disease progression or biliary obstruction (9/11; 82%). Most pts, 60/68 (88%), continued treatment despite an increase in ALT/AST grade. Among 8 pts who discontinued treatment, 3 were due to disease progression and 3 were due to adverse events. Median time for ALT/AST to return to BL was 9 days and there were no temporal increases in albumin or INR. Conclusions: Approximately 1/2 of tebe treated pts experienced an increase in post-BL CTCAE grade for ALT/AST. Among these pts, most ALT/AST increases were mild. Most of the pts with G3/4 ALT/AST increase (9/11) were explained by increase in size of liver metastases or biliary obstruction. Increase in LFT are not unusual at time of disease progression in mUM given high frequency of liver metastases. In summary, ALT/AST increases occurred early in about half of the pts, were generally self-limiting, permitted treatment to continue, and did not appear to impact liver synthetic function (INR/Albumin). Clinical trial information: NCT02570308.

Results of phase II randomized study of intermittent versus continuous schedule of vemurafenib plus cobimetinib in BRAF-mutated advanced melanoma

9528

Background: Combination of vemurafenib plus cobimetinib is approved for the treatment of BRAF-mutated advanced melanoma. Although patients initially respond to treatment, resistance emerges before 18 months in most cases. One of the key pre-clinical observations that supported an intermittent schedule was that resistant tumors suffer a fitness deficit in the absence of the drug, so modulation of the drug pressure through an intermittent dosing could delay the emergence of resistance. Methods: GEM1501 is a randomized phase 2 study comparing the activity of the combination of vemurafenib 960 mg every 12 h/d plus cobimetinib 60 mg/d in a standard (arm A) versus intermittent schedule (arm B). Arm A: four-week (w) cycles of daily vemurafenib for 4w plus cobimetinib for 3w-on and 1w-off-treatment. Arm B: first three cycles according to the standard schedule, followed by 6w-cycle with 2w-off vemurafenib & 3w-off cobimetinib. Primary endpoint was progression free survival (PFS) and secondary were objective response (OR) and treatment-related adverse events (TAEs). Results: 70 treatment-naïve patients were included. Results in arms A and B: median PFS 16.2 (95%CI 9.5, 24.1) vs 6.9 months (95%CI 5.2, 9.3) (p = 0.079); OR in 25 (71.4%) (8 complete -23%-) vs 21 (60%) patients (5 complete -14%-); G3-4 TAEs 42.8% vs 40.0%, respectively. Analysis of BRAFV600 mutation in tumoral cell free DNA (cfDNA) was performed in serial plasma samples in 41 patients. Twenty-one (51%) patients had detectable BRAFV600 mutation in pretreatment cfDNA (preBRAF+). Significant differences in PFS were found according to preBRAF V600: 8.2 months (95%CI 5.2, 13.6) in preBRAF+ vs non-reached (NR) (95%CI 2.8, NR) in preBRAF- (p = 0.017). In arm A, median PFS was 13.3 months (95% CI 4.6, NR) in preBRAF+ vs NR (95% CI 2.3, NR) in preBRAF-. In arm B, median PFS was 6.2 months (95% CI 0.3-8.3) in preBRAF+ vs NR (95%CI 2.8, NR) in preBRAF- (p = 0.003). BRAFV600 mutation became undetectable in cfDNA after treatment initiation in all preBRAF+ patients. Different kinetic of BRAFV600 mutation in cfDNA was found according to treatment arm. At progression, BRAFV600 reappeared in cfDNA in all (5/5) cases treated in arm B, but only in 50% (3/6) of cases in arm A. NGS analysis of cfDNA at progression suggested different resistance mechanisms. Conclusions: The results of this study do not support the use of an intermittent schedule of vemurafenib plus cobimetinib in advanced melanoma. BRAFV600 detection in pretreatment cfDNA is a prognostic factor of poor survival that it is independent of treatment schedule, although most striking differences favoring continuous arm vs intermittent arm were found in patients with detectable BRAFV600 mutation on pretreatment cfDNA. Further research is required to determine the clinical value of the analysis of resistance mechanisms in cfDNA. Clinical trial information: 2014-005277-36.

Characterization of cytokine release syndrome (CRS) following treatment with tebentafusp in patients (pts) with previously treated (2L+) metastatic uveal melanoma (mUM)

9531

Background: Cytokine-mediated adverse events (AEs) are commonly reported in pts treated with T cell engaging therapies. Tebentafusp (tebe), a bispecific consisting of an affinity-enhanced T cell receptor fused to an anti-CD3 effector that can redirect T cells to target gp100+ cells, has shown an overall survival benefit for pts with untreated mUM in a Ph3 trial (NCT03070392). Here we reviewed the incidence, kinetics, and outcome of CRS in tebe-treated pts on the IMCgp100-102 trial of 2L+ pts with mUM (NCT02570308). Methods: 127 HLA-A*02:01+ 2L+ mUM pts were treated with tebe at the RP2D of 68mcg following intra-patient dose escalation of 20 mcg dose 1 and 30 mcg dose 2. Pts were monitored overnight to allow management of hypotension and other cytokine-related AEs. Because the rate of severe CRS was low in Ph1, prophylactic corticosteroids, antihistamines or acetaminophen were not mandated. CRS was evaluated post-hoc according to ASTCT Consensus Grading criteria [1]. Circulating cytokines in serum were measured before and at 8hr and 12-24hr after dosing for the 1st, 3rd and 4th doses (n=105). This analysis was conducted on the primary analysis snapshot dated 04Jun20. Results: The most frequent treatment-related AEs that were likely cytokine-mediated included fever (80%), chills (64%), nausea (59%), hypotension (41%) and hypoxia (4%). In a post-hoc review using ASTCT criteria, 86% of pts (n=109) had any grade CRS. The majority of these 109 pts had either grade (G) 1 (n=42; 33%) or G2 (n=62; 49%), with few G3 (n=4; 3.1%), one G4 (0.8%), and no deaths. Onset of CRS began within 24 hours of administration and G≥2 hypotension or hypoxia typically resolved within 2 days of onset. Most CRS events occurred after the first 3 doses with a marked reduction in the frequency and severity of CRS thereafter; G3-4 CRS was limited to first two doses. Only 2 pts discontinued tebe due to CRS (1 G3 and 1 G4). Treatment of G≥2 CRS included iv fluids (n=45), iv steroids (n=18), oxygen (n=8), and vasopressor use (n=2). No pts received tocilizumab. Tebe induced a transient increase in peripheral cytokines, including IFNγ, IL-10, IL-6 and TNFα, within hours of tebe dosing, which were several fold higher in pts with CRS compared to pts without CRS. Higher levels of TNFα trended with severity of CRS. Conclusions: CRS, a common AE observed with all T cell engaging therapies, was frequently observed within 24 hours of initial tebe treatment. Most CRS events were mild or moderate in severity even without the use of prophylactic premedications, were reversible with standard management strategies, decreased in frequency and severity with subsequent doses, and rarely led to treatment discontinuation. Pts with CRS tended to have greater increases in serum cytokines, consistent with tebe’s proposed mechanism of action. [1] Lee, DW et al. Biol Blood Marrow Transplant 2019. Clinical trial information: NCT02570308.

Supramolecular rectangles through directional chalcogen bonding

Supramolecular rectangles are built from the 2+2 chalcogen bonding-based (ChB) association of 1,8-bis(telluromethylethynyl)-anthracene (BTMEA) and ditopic Lewis bases such as 4,4'-bipyridyl-ethane and analogs, demonstrating the strength and directionality of the ChB interaction in such alkynyl-telluroalkyl derivatives.

Development and Validation of an Early Mortality Risk Score for Older Patients Treated with Chemotherapy for Cancer

Background: Estimation of life expectancy in older patients is relevant to select the best treatment strategy. We aimed to develop and validate a score to predict early mortality in older patients with cancer. Patients and Methods: A total of 749 patients over 70 years starting new chemotherapy regimens were prospectively included. A prechemotherapy assessment that included sociodemographic variables, tumor/treatment variables, and geriatric assessment variables was performed. Association between these factors and early death was examined using multivariable logistic regression. Score points were assigned to each risk factor. External validation was performed on an independent cohort. Results: In the training cohort, the independent predictors of 6-month mortality were metastatic stage (OR 4.8, 95% CI [2.4–9.6]), ECOG-PS 2 (OR 2.3, 95% CI [1.1–5.2]), ADL ≤ 5 (OR 1.7, 95% CI [1.1–3.5]), serum albumin levels ≤ 3.5 g/dL (OR 3.4, 95% CI [1.7–6.6]), BMI < 23 kg/m² (OR 2.5, 95% CI [1.3–4.9]), and hemoglobin levels < 11 g/dL (OR 2.4, 95% CI (1.2–4.7)). With these results, we built a prognostic score. The area under the ROC curve was 0.78 (95% CI, 0.73 to 0.84), and in the validation set, it was 0.73 (95% CI: 0.67–0.79). Conclusions: This simple and highly accurate tool can help physicians making decisions in elderly patients with cancer who are planned to initiate chemotherapy treatment.

Cancer immunotherapy in special challenging populations: recommendations of the Advisory Committee of Spanish Melanoma Group (GEM)

Cancer immunotherapy based on the use of antibodies targeting the so-called checkpoint inhibitors, such as programmed cell death-1 receptor, its ligand, or CTLA-4, has shown durable clinical benefit and survival improvement in melanoma and other tumors. However, there are some special situations that could be a challenge for clinical management. Persons with chronic infections, such as HIV-1 or viral hepatitis, latent tuberculosis, or a history of solid organ transplantation, could be candidates for cancer immunotherapy, but their management requires a multidisciplinary approach. The Spanish Melanoma Group (GEM) panel in collaboration with experts in virology and immunology from different centers in Spain reviewed the literature and developed evidence-based guidelines for cancer immunotherapy management in patients with chronic infections and immunosuppression. These are the first clinical guidelines for cancer immunotherapy treatment in special challenging populations. Cancer immunotherapy in chronically infected or immunosuppressed patients is feasible but needs a multidisciplinary approach in order to decrease the risk of complications related to the coexistent comorbidities.

Prediction of Unplanned Hospitalizations in Older Patients Treated with Chemotherapy

PURPOSE

To determine the incidence of unplanned hospitalization (UH) and to identify risk factors for UH in elderly patients with cancer who start chemotherapy.

METHODS

In all, 493 patients over 70 years starting new chemotherapy regimens were prospectively included. A pre-chemotherapy geriatric assessment was performed, and tumor and treatment variables were collected. The association between these factors and UH was examined by using multivariable logistic regression. Score points were assigned to each risk factor.

RESULTS

During the first 6 months of treatment, 37% of patients had at least one episode of UH. Risk factors were the use of combination chemotherapy at standard doses, a MAX2 index ≥1, a Charlson comorbidity score ≥2, albumin level <3.5 g/dL, falls in the past 6 months ≥1, and weight loss >5%. Three risk groups for UH were established according to the score in all patients: 0-1: 17.5%; 2: 34%; and 3-7: 57% (p < 0.001). The area under receiver operation characteristic (ROC) curve was 0.72 (95% CI: 0.67-0.77).

CONCLUSION

This simple tool can help to reduce the incidence of UH in elderly patients with cancer who are scheduled to initiate chemotherapy treatment.

SEOM clinical guideline for the management of cutaneous melanoma (2020)

Melanoma affects about 6000 patients a year in Spain. A group of medical oncologists from Spanish Society of Medical Oncology (SEOM) and Spanish Multidisciplinary Melanoma Group (GEM) has designed these guidelines to homogenize the management of these patients. The diagnosis must be histological and determination of BRAF status has to be performed in patients with stage ≥ III. Stage I–III resectable melanomas will be treated surgically. In patients with stage III melanoma, adjuvant treatment with immunotherapy or targeted therapy is also recommended. Patients with unresectable or metastatic melanoma will receive treatment with immunotherapy or targeted therapy, the optimal sequence of these treatments remains unclear. Brain metastases require a separate consideration, since, in addition to systemic treatment, they may require local treatment. Patients must be followed up closely to receive or change treatment as soon as their previous clinical condition changes, since multiple therapeutic options are available.

Abstract PD14-03: Molecular mechanism of ipatasertib (IPAT) and its combination with atezolizumab (atezo) in patients (pts) with locally advanced/metastatic triple-negative breast cancer (aTNBC)

Background: Phase 3 trials (IMpassion130, KEYNOTE-355) have shown improved efficacy with the addition of immune checkpoint modulators to chemotherapy in PD-L1 +ve aTNBC. However, unmet need remains in the ~60% of pts with aTNBC who have PD-L1 -ve tumors. Preliminary data from a multicenter phase 1b study (NCT03800836) evaluating the safety and efficacy of the oral AKT inhibitor IPAT + atezo + paclitaxel/nab-paclitaxel showed promising antitumor activity (73% confirmed objective response rate) irrespective of PD-L1 status [Schmid, AACR 2019], suggesting a potential role for the triplet independent of PD-L1 status. We report on-treatment changes in the tumor microenvironment in Cohort 2.

Methods: In Cohort 2, pts with aTNBC and ≤2 prior lines of chemotherapy for aTNBC received oral IPAT 400 mg on d1-28 of cycle 1 (35-d cycle) and on d1-21 of subsequent cycles (28-d cycles). IV atezo 840 mg was given on d8 & 22 of cycle 1 and on d1 & 15 of subsequent cycles. Biopsies were collected before treatment administration during cycle 1 on d1 (C1D1) & d8 (C1D8), and on d15 of cycle 2 (C2D15). PD-L1 (VENTANA SP142 immune cell ≥1%) and CD8 expression was assessed by immunohistochemistry (IHC); % immune infiltrate was measured by H&E staining. Changes in gene expression were assessed by RNA-Seq. Gene set enrichment analysis was used to study molecular pathway activation (enrichment score [ES] &gt;0 to 1) or inhibition (ES -1 to &lt;0).

Results: In Cohort 2, 11 pts had PD-L1 -ve tumors at baseline and are included in the analyses below, 2 had PD-L1 +ve tumors and 3 were unevaluable for PD-L1. IHC analysis of serial biopsies from pts with PD-L1 -ve tumors showed a statistically significant increase in immune infiltrates (mean % infiltrates C1D8/C1D1=1.44; p=0.042) and a trend toward increased CD8 protein expression (mean CD8 % staining C1D8/C1D1=1.75; Kruskal-Wallis p=0.16) at the tumor center during the first week of single-agent IPAT compared with the baseline biopsy. An increase in PD-L1 expression (mean PD-L1 % infiltrating immune cells C2D15/C1D1=4.33; Kruskal-Wallis p=0.044) was seen during IPAT + atezo combination treatment. No significant changes in immune infiltrates or CD8 expression were observed after initiating atezo versus IPAT alone. As expected, MTORC1 activity decreased (ES=-0.43; p&lt;0.005) in response to IPAT. IPAT (± atezo) enhanced key immunogenic pathways, including antigen processing and presentation (ES=0.49; p&lt;0.005), allograft rejection (ES=0.47; p&lt;0.0001), inflammatory response (ES=0.34; p&lt;0.05), and NK cell activation (ES=0.66; p&lt;0.05). In addition, IPAT + atezo enhanced TCR signaling (ES=0.52; p&lt;0.0005) and interferon gamma response (ES=0.30; p&lt;0.05). IPAT treatment was associated with decreased expression of gene sets predicting pathway upregulation, including E2F signaling, G2M checkpoint, and MYC activity. IPAT was also associated with apoptotic pathway enrichment. Using a syngeneic melanoma mouse model, we validated clinical findings and identified additional molecular changes after treatment with IPAT and/or anti-PD-L1. To date, 3 enrolled pts achieved a partial response and 6 had stable disease. Clinical and preclinical studies are ongoing to explore associations between treatment-driven molecular changes and clinical response.

Conclusion: Inhibition of AKT signaling may remodel the microenvironment of PD-L1 -ve tumors by increasing immune infiltration, priming immune pathways, promoting tumor cell apoptosis, and inhibiting oncogenic cell proliferative pathways. To our knowledge, these are the first reports evaluating molecular changes during AKT-targeted therapy for aTNBC in the context of immunotherapy irrespective of PD-L1 status. IPAT warrants further investigation combined with atezo as treatment for PD-L1 -ve aTNBC.

Citation Format: Peter Schmid, Delphine Loirat, Peter Savas, Enrique Espinosa, Valentina Boni, Antoine Italiano, Shane White, Victor Laliman, Geraldine Strasser, Kui Lin, Karen Cheng, Aruna Mani, Matthew Wongchenko, Marie-Paule Sablin, Kalpit Shah. Molecular mechanism of ipatasertib (IPAT) and its combination with atezolizumab (atezo) in patients (pts) with locally advanced/metastatic triple-negative breast cancer (aTNBC) [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD14-03.