Recovery of rare earth elements (Nd3+ and Dy3+) by using carbon-based adsorbents from spent tire rubber

Two samples of spent tire rubber (rubber A and rubber B) were submitted to thermochemical conversion by pyrolysis process. A450, B450 and A900, B900 chars were obtained from rubber A and rubber B at 450 °C and 900 °C, respectively. The chars were then applied as recovery agents of Nd3+ and Dy3+ from aqueous solutions in mono and bicomponent solutions, and their performance was benchmarked with a commercial activated carbon. The chars obtained at 900 °C were the most efficient adsorbents for both elements with uptake capacities around 30 mg g-1. The chars obtained at 450 °C presented uptake capacities similar to the commercial carbon (≈ 11 mg g-1). A900 and B900 chars presented a higher availability of Zn ions that favored the ion exchange mechanism. It was found that Nd3+ and Dy3+ were adsorbed as oxides after Zn was released from silicate structures (Zn2SiO4). A900 char was further selected to be tested with Nd/Dy binary mixtures and it was found a trend to adsorb a slightly higher amount of Dy3+ due to its smaller ionic radius. The uptake capacity in bicomponent solutions was generally higher than for single component solutions due to the higher driving force triggered by the higher concentration gradient.

Survival and safety after neoadjuvant chemotherapy or upfront surgery for locally advanced colon cancer: meta-analysis

BACKGROUND

Neoadjuvant chemotherapy is increasingly used to treat locally advanced (T3-4 Nx-2 M0) colon cancer due to its potential advantages over the standard approach of upfront surgery. The primary objective of this systematic review and meta-analysis was to analyse data from comparative studies to assess the impact of neoadjuvant chemotherapy on oncological outcomes.

METHODS

A systematic review was conducted by searching the MEDLINE and Scopus databases. The search encompassed RCTs, propensity score-matched studies, and controlled prospective studies published up to 1 April 2023. As a primary objective, overall survival and disease-free survival were compared. As a secondary objective, perioperative morbidity, mortality, and complete resection were compared using the DerSimonian and Laird models.

RESULTS

A total of seven studies comprising a total of 2120 patients were included. Neoadjuvant chemotherapy was associated with a reduction in the hazard of recurrence (HR 0.73, 95% c.i. 0.59 to 0.90; P = 0.003) and death (HR 0.67, 95% c.i. 0.54 to 0.83; P < 0.001) compared with upfront surgery. Additionally, neoadjuvant chemotherapy was significantly associated with higher 5-year overall survival (79.9% versus 72.6%; P < 0.001) and disease-free survival (73.1% versus 64.5%; P = 0.028) rates. No significant differences were observed in perioperative mortality (OR 0.97, 95% c.i. 0.28 to 3.33), overall complications (OR 0.95, 95% c.i. 0.77 to 1.16), or anastomotic leakage/intra-abdominal abscess (OR 0.88, 95% c.i. 0.60 to 1.29). However, neoadjuvant chemotherapy was associated with a lower risk of incomplete resection (OR 0.70, 95% c.i. 0.49 to 0.99).

CONCLUSION

Neoadjuvant chemotherapy is associated with a reduced hazard of recurrence and death, as well as improved overall survival and disease-free survival rates, compared with upfront surgery in patients with locally advanced colon cancer.

Fcγ receptors and immunomodulatory antibodies in cancer

The discovery of both cytotoxic T lymphocyte-associated antigen 4 (CTLA4) and programmed cell death protein 1 (PD1) as negative regulators of antitumour immunity led to the development of numerous immunomodulatory antibodies as cancer treatments. Preclinical studies have demonstrated that the efficacy of immunoglobulin G (IgG)-based therapies depends not only on their ability to block or engage their targets but also on the antibody's constant region (Fc) and its interactions with Fcγ receptors (FcγRs). Fc-FcγR interactions are essential for the activity of tumour-targeting antibodies, such as rituximab, trastuzumab and cetuximab, where the killing of tumour cells occurs at least in part due to these mechanisms. However, our understanding of these interactions in the context of immunomodulatory antibodies designed to boost antitumour immunity remains less explored. In this Review, we discuss our current understanding of the contribution of FcγRs to the in vivo activity of immunomodulatory antibodies and the challenges of translating results from preclinical models into the clinic. In addition, we review the impact of genetic variability of human FcγRs on the activity of therapeutic antibodies and how antibody engineering is being utilized to develop the next generation of cancer immunotherapies.

Druggable Targets in Cytokine Release Syndromes

Bispecific T-cell engagers and chimeric antigen receptor T cells share the problem of eliciting acute systemic inflammation episodes known as cytokine release syndrome. Knowledge on the sequential waves of cytokines that can be neutralized with clinically available agents is crucial to prevent or treat this condition without jeopardizing the antitumor therapeutic outcome. See related article by Leclercq-Cohen et al., p. 4449.

Exploring the Immunogenicity of Noncanonical HLA-I Tumor Ligands Identified through Proteogenomics

PURPOSE

Tumor antigens are central to antitumor immunity. Recent evidence suggests that peptides from noncanonical (nonC) aberrantly translated proteins can be presented on HLA-I by tumor cells. Here, we investigated the immunogenicity of nonC tumor HLA-I ligands (nonC-TL) to better understand their contribution to cancer immunosurveillance and their therapeutic applicability.

EXPERIMENTAL DESIGN

Peptides presented on HLA-I were identified in 9 patient-derived tumor cell lines from melanoma, gynecologic, and head and neck cancer through proteogenomics. A total of 507 candidate tumor antigens, including nonC-TL, neoantigens, cancer-germline, or melanocyte differentiation antigens, were tested for T-cell recognition of preexisting responses in patients with cancer. Donor peripheral blood lymphocytes (PBL) were in vitro sensitized against 170 selected nonC-TL to isolate antigen-specific T-cell receptors (TCR) and evaluate their therapeutic potential.

RESULTS

We found no recognition of the 507 nonC-TL tested by autologous ex vivo expanded tumor-reactive T-cell cultures while the same cultures demonstrated reactivity to mutated, cancer-germline, or melanocyte differentiation antigens. However, in vitro sensitization of donor PBL against 170 selected nonC-TL, led to the identification of TCRs specific to three nonC-TL, two of which mapped to the 5' UTR regions of HOXC13 and ZKSCAN1, and one mapping to a noncoding spliced variant of C5orf22C. T cells targeting these nonC-TL recognized cancer cell lines naturally presenting their corresponding antigens. Expression of the three immunogenic nonC-TL was shared across tumor types and barely or not detected in normal cells.

CONCLUSIONS

Our findings predict a limited contribution of nonC-TL to cancer immunosurveillance but demonstrate they may be attractive novel targets for widely applicable immunotherapies. See related commentary by Fox et al., p. 2173.

Low Risk of Hyperprogression with First-Line Chemoimmunotherapy for Advanced Non-Small Cell Lung Cancer: Pooled Analysis of 7 Clinical Trials

BACKGROUND

Monotherapy immune checkpoint inhibitor (ICI) used in second- or later-line settings has been reported to induce hyperprogression. This study evaluated hyperprogression risk with ICI (atezolizumab) in the first-, second-, or later-line treatment of advanced non-small cell lung cancer (NSCLC), and provides insights into hyperprogression risk with contemporary first-line ICI treatment.

METHODS

Hyperprogression was identified using Response Evaluation Criteria in Solid Tumours (RECIST)-based criteria in a dataset of pooled individual-participant level data from BIRCH, FIR, IMpower130, IMpower131, IMpower150, OAK, and POPLAR trials. Odds ratios were computed to compare hyperprogression risks between groups. Landmark Cox proportional-hazard regression was used to evaluate the association between hyperprogression and progression-free survival/overall survival. Secondarily, putative risk factors for hyperprogression among second- or later-line atezolizumab-treated patients were evaluated using univariate logistic regression models.

RESULTS

Of the included 4644 patients, 119 of the atezolizumab-treated patients (n = 3129) experienced hyperprogression. Hyperprogression risk was markedly lower with first-line atezolizumab-either chemoimmunotherapy or monotherapy-compared to second/later-line atezolizumab monotherapy (0.7% vs. 8.8%, OR = 0.07, 95% CI, 0.04-0.13). Further, there was no statistically significant difference in hyperprogression risk with first-line atezolizumab-chemoimmunotherapy versus chemotherapy alone (0.6% vs. 1.0%, OR = 0.55, 95% CI, 0.22-1.36). Sensitivity analyses using an extended RECIST-based criteria including early death supported these findings. Hyperprogression was associated with worsened overall survival (HR = 3.4, 95% CI, 2.7-4.2, P < .001); elevated neutrophil-to-lymphocyte ratio was the strongest risk factor for hyperprogression (C-statistic = 0.62, P < .001).

CONCLUSIONS

This study presents first evidence for a markedly lower hyperprogression risk in advanced NSCLC patients treated with first-line ICI, particularly with chemoimmunotherapy, as compared to second- or later-line ICI treatment.

Anti-CTLA-4 antibodies drive myeloid activation and reprogram the tumor microenvironment through FcγR engagement and type I interferon signaling

Despite the clinical success of checkpoint inhibitors, a substantial gap still exists in our understanding of their mechanism of action. While antibodies to cytotoxic T lymphocyte-associated protein-4 (CTLA-4) were developed to block inhibitory signals in T cells, several recent studies have demonstrated that Fcγ receptor (FcγR)-dependent depletion of regulatory T cells (Treg) is critical for antitumor activity. Here, using single-cell RNA sequencing, we dissect the impact of anti-CTLA-4-blocking, Treg cell-depleting and FcR-engaging activity on the immune response within tumors. We observed a rapid remodeling of the innate immune landscape as early as 24 h after treatment. Using genetic Treg cell ablation models, we show that immune remodeling was not driven solely by Treg cell depletion or CTLA-4 blockade but mainly through FcγR engagement, downstream activation of type I interferon signaling and reduction of suppressive macrophages. Our findings indicate that FcγR engagement and innate immune remodeling are involved in successful anti-CTLA-4 treatment, supporting the development of optimized immunotherapy agents bearing these features.

Safety and preliminary activity results of the GATTO study, a phase Ib study combining the anti-TA-MUC1 antibody gatipotuzumab with the anti-EGFR tomuzotuximab in patients with refractory solid tumors

BACKGROUND

The phase I GATTO study (NCT03360734) explored the feasibility, tolerability and preliminary activity of combining gatipotuzumab, a novel humanized monoclonal antibody binding to the tumor-associated epitope of mucin 1 (TA-MUC1) and an anti-epidermal growth factor receptor (anti-EGFR) antibody in refractory solid tumors.

PATIENTS AND METHODS

Initially the study enrolled primary phase (PP) patients with EGFR-positive metastatic solid tumors, for whom no standard treatment was available. Patients received gatipotuzumab administered at 1400 mg every 2 weeks, 6 weeks after the start of the glyco-optimized anti-EGFR antibody tomuzotuximab at 1200 mg every 2 weeks. As this regimen was proven safe, enrollment continued in an expansion phase (EP) of patients with refractory metastatic colorectal cancer, non-small-cell lung cancer, head and neck cancer and breast cancer. Tomuzotuximab and gatipotuzumab were given at the same doses and gatipotuzumab treatment started 1 week after the first dose of the anti-EGFR antibody. Additionally, investigators could use a commercial anti-EGFR antibody in place of tomuzotuximab.

RESULTS

A total of 52 patients were enrolled, 20 in the PP and 32 in the EP. The combined treatment was well tolerated and no dose-limiting toxicity was observed in the whole study, nor related serious adverse event or death. Preliminary activity of the combination was observed, with one and four RECIST partial responses in the PP and EP, all in colorectal cancer patients. The trial was accompanied by a comprehensive translational research program for identification of biomarkers, including soluble TA-MUC1 (sTA-MUC1) in serum. In the EP, patients with baseline sTA-MUC1 levels above the median appeared to have improved progression-free survival and overall survival.

CONCLUSIONS

Combination of a TA-MUC1-targeting antibody and an EGFR-targeting antibody is safe and feasible. Interesting antitumor activity was observed in heavily pretreated patients. Future studies should test this combination together with chemotherapy and explore the potential of sTA-MUC1 as a companion biomarker for further development of the combination.

912 Preferential recognition of neoantigens over non-canonical peptides in cancer patients

Background

Despite recent advances in exome and RNA sequencing to identify tumor-rejection antigens including neoantigens, the existing techniques fail to identify the vast majority of antigens targeted by tumor-reactive cells. A growing number of studies suggest that HLA-I peptides derived from non-canonical (nonC) open reading frames or derived from allegedly non-coding regions can contribute to tumor immunogenicity. Here we use proteogenomics to identify personalized candidate canonical and non-canonical tumor-rejection antigens and to evaluate their contribution to cancer immune surveillance in patients.

Methods

Whole exome sequencing was performed to identify the non-synonymous somatic mutations (NSM) and immunopeptidomics to identify the HLA-I presented peptides (pHLA) in 9 patient-derived tumor cell lines (TCL). Peptid-PRISM proteogenomics pipeline was used to identify both canonical and non-canonical pHLA, including those derived from NSM in coding regions. All peptides containing mutations and derived from either cancer-testis (CTA) or tumor-associated antigens (TAA) were selected as candidate tumor antigens. For nonC peptides, an immunopeptidomics healthy dataset containing several tissues and HLA-allotypes was used to eliminate those derived from normal ORFs and select nonC peptides preferentially expressed in tumor cells (nonC-TE). The selected candidate peptides were synthesized, pulsed onto autologous APCs and co-cultured with tumor-reactive ex vivo expanded lymphocytes to assess immune recognition (figure 1).

Results

NonC-TE peptides were identified in all TCL studied, ranging from 0.5% to 5.4% of the total HLA-I presented peptides (n= 506). As described previoulsy, 5’UTR were the main source. Of note, the tumor type did not have an impact on the frequency of presented nonC peptides, but rather the presence of HLA-A*11:01 and HLA-A*03:01 was a major determinant. T cell responses were detected against at least 13/33 putative neoantigens, 2/24 CTA and 2/61 TAA. On the contrary, none of the 471 nonC-TE candidate peptides tested thus far, including one containing a NSM were able to elicit a recall immune response. Nevertheless, T cells recognizing at least 3 of them were detected through in vitro sensitization of non-autologous PBMCs.

Abstract 912 Figure 1

Workflow diagram

Tumor biopsies and blood samples are obtained from cancer patients (left panel). Patient-derived tumor cell lines are generated in vitro, the peptides presented on HLA molecules are further isolated and analyzed in a mass-spectrometer (top panel). Whole exome sequencing (WES) from matched tumor and healthy tissue is performed to identify the non-synonymous somatic mutations (NSM) (middle panel). Peptide-PRISM proteogenomics pipeline combines the information from the immunopeptidomics data and WES to identify pHLA sequences from both canonical and non-canonical candidate tumor antigens (top right panel). Lymphocyte populations either TILs or sorted PBMCs are expanded and further screened for pre-existing T cell responses (bottom panel) against the candidate epitopes by co-culturing the T cells with peptide-pulsed autologous APC. The recognition is assessed by measuring IFNg release by elispot and the upregulation of activation surface markers by FACS (bottom right panel).

Conclusions

Our results show that although HLA-I nonC peptides were frequently presented in all TCLs studied and they can be immunogenic, neoantigens derived from mutations in canonical coding regions were preferentially recognized by tumor-reactive lymphocytes, suggesting T cells targeting the latter are primed more efficiently. The identification of mutated nonC antigens using whole genome sequencing to identify mutations in non-coding regions warrants further examination. Still, the specificity of many tumor-reactive TILs remains unknown.

Ethics Approval

”This study was approved by the ”Comité de Ética de Investigación con Medicamentos del Hospital Universitario Vall d’Hebron” institution’s Ethics Board; approval number PR(AG)537/2019.”

Phase I prognostic online (PIPO): A web tool to improve patient selection for oncology early phase clinical trials

PURPOSE

Patient selection in phase 1 clinical trials (Ph1t) continues to be a challenge. The aim of this study was to develop a user-friendly prognostic calculator for predicting overall survival (OS) outcomes in patients to be included in Ph1t with immune checkpoint inhibitors (ICIs) or targeted agents (TAs) based on clinical parameters assessed at baseline.

METHODS

Using a training cohort with consecutive patients from the VHIO phase 1 unit, we constructed a prognostic model to predict median OS (mOS) as a primary endpoint and 3-month (3m) OS rate as a secondary endpoint. The model was validated in an internal cohort after temporal data splitting and represented as a web application.

RESULTS

We recruited 799 patients (training and validation sets, 558 and 241, respectively). Median follow-up was 21.2 months (m), mOS was 10.2 m (95% CI, 9.3-12.7) for ICIs cohort and 7.7 m (95% CI, 6.6-8.6) for TAs cohort. In the multivariable analysis, six prognostic variables were independently associated with OS - ECOG, number of metastatic sites, presence of liver metastases, derived neutrophils/(leukocytes minus neutrophils) ratio [dNLR], albumin and lactate dehydrogenase (LDH) levels. The phase 1 prognostic online (PIPO) calculator showed adequate discrimination and calibration performance for OS, with C-statistics of 0.71 (95% CI 0.64-0.78) in the validation set. The overall accuracy of the model for 3m OS prediction was 87.2% (95% CI 85%-90%).

CONCLUSIONS

PIPO is a user-friendly objective and interactive tool to calculate specific survival probabilities for each patient before enrolment in a Ph1t. The tool is available at https://pipo.vhio.net/.

Pralsetinib for patients with advanced or metastatic RET-altered thyroid cancer (ARROW): a multi-cohort, open-label, registrational, phase 1/2 study

BACKGROUND

Oncogenic alterations in RET represent important therapeutic targets in thyroid cancer. We aimed to assess the safety and antitumour activity of pralsetinib, a highly potent, selective RET inhibitor, in patients with RET-altered thyroid cancers.

METHODS

ARROW, a phase 1/2, open-label study done in 13 countries across 71 sites in community and hospital settings, enrolled patients 18 years or older with RET-altered locally advanced or metastatic solid tumours, including RET-mutant medullary thyroid and RET fusion-positive thyroid cancers, and an Eastern Co-operative Oncology Group performance status of 0-2 (later limited to 0-1 in a protocol amendment). Phase 2 primary endpoints assessed for patients who received 400 mg once-daily oral pralsetinib until disease progression, intolerance, withdrawal of consent, or investigator decision, were overall response rate (Response Evaluation Criteria in Solid Tumours version 1.1; masked independent central review) and safety. Tumour response was assessed for patients with RET-mutant medullary thyroid cancer who had received previous cabozantinib or vandetanib, or both, or were ineligible for standard therapy and patients with previously treated RET fusion-positive thyroid cancer; safety was assessed for all patients with RET-altered thyroid cancer. This ongoing study is registered with clinicaltrials.gov, NCT03037385, and enrolment of patients with RET fusion-positive thyroid cancer was ongoing at the time of this interim analysis.

FINDINGS

Between Mar 17, 2017, and May 22, 2020, 122 patients with RET-mutant medullary and 20 with RET fusion-positive thyroid cancers were enrolled. Among patients with baseline measurable disease who received pralsetinib by July 11, 2019 (enrolment cutoff for efficacy analysis), overall response rates were 15 (71%) of 21 (95% CI 48-89) in patients with treatment-naive RET-mutant medullary thyroid cancer and 33 (60%) of 55 (95% CI 46-73) in patients who had previously received cabozantinib or vandetanib, or both, and eight (89%) of nine (95% CI 52-100) in patients with RET fusion-positive thyroid cancer (all responses confirmed for each group). Common (≥10%) grade 3 and above treatment-related adverse events among patients with RET-altered thyroid cancer enrolled by May 22, 2020, were hypertension (24 patients [17%] of 142), neutropenia (19 [13%]), lymphopenia (17 [12%]), and anaemia (14 [10%]). Serious treatment-related adverse events were reported in 21 patients (15%), the most frequent (≥2%) of which was pneumonitis (five patients [4%]). Five patients [4%] discontinued owing to treatment-related events. One (1%) patient died owing to a treatment-related adverse event.

INTERPRETATION

Pralsetinib is a new, well-tolerated, potent once-daily oral treatment option for patients with RET-altered thyroid cancer.

FUNDING

Blueprint Medicines.

Activity results of the GATTO study, a phase Ib study combining the anti-TA-MUC1 antibody gatipotuzumab with the anti-EGFR tomuzotuximab or panitumumab in patients with refractory solid tumors

2522

Background: The phase I GATTO study explored the feasibility, tolerability and preliminary activity of combining Gatipotuzumab (GAT), a novel humanized monoclonal antibody binding to the tumor-associated epitope of mucin-1 (TA-MUC1), and an anti-EGFR antibody. Preclinical evidence suggests a complex interaction between TA-MUC1 and EGFR on the cell surface of epithelial tumors and synergistic antibody dependent cell cytotoxicity activity with the double targeting. Methods: Initially 20 patients with refractory metastatic disease were treated with GAT administered at 1400 mg Q2W in combination with the glyco-optimized anti-EGFR antibody Tomuzotuximab (TOM) at 1200 mg Q2W. Due to the risk of infusion related reactions, three cycles of TOM were given before start of combined treatment with GAT. After this regimen was proven safe and no DLT was observed, 30 additional patients including colorectal cancer (CRC) already treated with anti-EGFR antibodies, non-small cell lung cancer (NSCLC), head and neck and breast cancers received TOM and GAT administered at the same doses, with GAT treatment starting already one week after the first dose of the anti-EGFR antibody. As allowed in the study expansion, Panitumumab (PAN) was used in place of TOM in 9 CRC patients at investigator’s choice. Results: By the time of the final analysis in January 2021, 52 patients were enrolled, and 50 received at least one dose of both GAT and anti-EGFR antibodies. Safety was overall good and results are reported in a separate abstract. Because of the difference in treatment schedule, activity results of the two parts of the study are summarized separately. There were 2 and 4 RECIST partial responses in the first and second part of the study, all in CRC patients. In the expansion phase, the median Progression Free Survival (PFS) of CRC patients who received TOM (10) and PAN (9) was 1.9 and 5.5 months, respectively. There were 2 responses in each subgroup and the duration of response was 3.8 and 7.2 months in patients receiving TOM and PAN, respectively. The PFS for NSCLC was 5.3 months and 2 heavily pretreated patients achieved a prolonged control of disease of 10.6 and 9.4 months. The trial was accompanied by a comprehensive translational research program for identification of biomarkers, including soluble TA-MUC1 in serum. In the extension phase patients with baseline values above median appeared to have improved PFS and overall survival; this was not the case for patients of the first part of the study who received GAT only after 3 doses of TOM. Conclusions: Combination of TA-MUC1 and EGFR targeting antibody is safe and feasible. Interesting anti-tumor activity was observed in heavily pretreated CRC and NSCLC patients. Levels of soluble TA-MUC1 may have predictive value and potentially be a companion biomarker for further development of the combination Clinical trial information: NCT03360734.

Impact of circulating tumor DNA (ctDNA) detection on survival outcomes of patients (pts) treated with immune-checkpoint inhibitors (ICIs) in early clinical trials

2542

Background: Detection of ctDNA is a promising tool for managing pts in oncology. Most methods require whole-genome sequencing of tumor samples followed by the design of personalized panels for tracking purposes. In this work, we evaluated the prognostic and predictive value of total ctDNA quantification, using shallow whole-genome sequencing (shWGS) exclusively from plasma samples, in a prospective cohort of pts treated with ICIs in early clinical trials. Methods: IchorCNA pipeline was used to quantify ctDNA of shWGS from plasma ctDNA samples of pts treated with ICIs in phase 1 trials, collected at baseline and prior to cycle 2 (prec2). We investigated the association and correlation of ctDNA levels with surrogate markers for tumor burden (LDH levels, summatory of target lesions (TL), liver metastasis) using Spearman and Kruskal-Wallis tests. Kaplan-Meier estimates of overall survival (OS) of pts with baseline detectable ctDNA levels versus undetectable ctDNA were calculated. A multivariate Cox proportional hazards model, including continuous classical prognostic factors (LDH, albumin, hemoglobin, derived Neutrophil-to-Lymphocyte ratio (dNLR), platelets, number of metastases sites, ECOG PS) and ctDNA was performed. An estimate of progression free survival (PFS) of pts with ctDNA increase levels in preC2 versus a non-increase group was evaluated. Results: Since January 2018, 113 pts with no standard-treatment options were included. Median (m) follow up was 14.8 months (mo). Baseline ctDNA levels correlated significantly with baseline TL (R = 0.4, p < 0.001) and LDH levels (R = 0.61, p < 0.001). Pts with liver metastasis had higher levels of ctDNA (11,68 ng/ml) versus pts with no liver disease (2,31 ng/ml) (p < 0,001). In the survival analysis pts with detectable baseline ctDNA (74 pts) had significantly shorter OS compared with pts with undetectable ctDNA (39 pts); median 9.6 m (8.4 – 16.4) and NA m (13.6-NA), respectively (HR = 2.25 [1.18-4.29] p < 0.01). In the multivariate analysis, only ctDNA and albumin levels maintained the impact in OS (HR = 1.03, p < 0.05 and HR = 0.22, p < 0.05, respectively). Pts with early increases in ctDNA had a shorter PFS compared with those with a stabilization or decrease, median 1.9 m (1.6 – 4.0) and 3.0 m (2.6 – 3.8), respectively (HR = 2.19 [1.31-3.67], p < 0.01). Conclusions: Quantification of baseline ctDNA using shWGS is a strong independent prognostic factor. Early dynamic changes of ctDNA could be a useful tool to predict PFS outcomes.

Safety and tolerability results of the GATTO study, a phase Ib study combining the anti-TA-MUC1 antibody gatipotuzumab with the anti-EGFR tomuzotuximab or panitumumab in patients with refractory solid tumors

2524

Background: The phase I GATTO study explored the feasibility, tolerability and preliminary activity of combining gatipotuzumab (GAT), a novel humanized monoclonal antibody binding to the tumor-associated epitope of mucin-1 (TA-MUC1) and an anti-EGFR antibody. Preclinical evidence suggests a complex interaction between TA-MUC1 and EGFR on the cell surface of epithelial tumors driving carcinogenesis processes and synergistic antibody dependent cell cytotoxicity activity with the dual targeting. Methods: Initially the study enrolled in a primary phase (PP) 20 patients with EGFR positive metastatic solid tumors, for whom no standard treatment was available. The first 6 patients were enrolled into a safety run-in phase and the number of dose-limiting toxicities (DLTs) was evaluated, in order to de-escalate the doses if needed. Patients received GAT administered at 1400 mg Q2W in combination with the glyco-optimized anti-EGFR antibody tomuzotuximab (TOM) at 1200 mg Q2W. Due to the risk of infusion related reactions (IRR), the first dose of TOM was reduced to 720 mg split over 2 consecutive days and three cycles of TOM monotherapy were given before start of treatment with GAT. As this regimen was proven safe, no DLT was observed and the initial dose remained unchanged, the study was amended to enroll in an expansion phase (EP) 30 additional patients with refractory colorectal cancer (CRC), non-small cell lung cancer (NSCLC), head and neck and breast cancers. TOM and GAT were given at the same doses and GAT treatment started already one week after the first dose of the anti-EGFR antibody. Additionally investigator had the choice to use a commercial anti-EGFR antibody in place of TOM. Results: By the time of the final analysis in January 2021, 52 refractory patients were enrolled and 50 received at least one dose of both GAT and anti-EGFR antibodies. Panitumumab (PAN) was used in 9 CRC patients. Because of the difference in treatment schedule, results are summarized separately for the 20 and 30 patients in PP and EP. Overall, the combined treatment was well tolerated and no DLT was observed in the whole study, nor related SAE or death. There were no treatment emergent adverse events (TEAEs) leading to dose interruptions or reductions in the PP and 2/30 (6.7%) patients in EP stopped both TOM and GAT. 16 IRRs were reported in 8/20 (40%) PP patients, and 40 IRRs in 10 (33.3%) EP patients. Only one event of chills was severe and only 6 events were related to GAT in the EP, all others to TOM. Other frequent TEAEs were those commonly observed with anti-EGFR treatment such as skin toxicity in 17 (85%) PP and 26 (86.7%) EP patients and hypomagnesemia in 10 (50%) PP and 7 (23.3%) EP patients. Conclusions: Combination of TA-MUC1 and EGFR targeting antibody is safe and feasible. Future studies should test this combination together with chemotherapy Clinical trial information: NCT03360734.

Evaluating the role of immune-checkpoint inhibitor (ICI) combinations in patients (pts) with unselected “cold” tumors enrolled in early clinical trials (CT)

2597

Background: In order to improve the expected response rate (ORR) of less than 10% in cold tumors, several ICI combinations are being evaluated in clinical trials. However, most of these trials don’t require any biomarker and pts are included based solely in histology. We aimed to assess the benefit of ICI combinations in pts with unselected cold tumors included in early CT. Methods: ICI naïve pts with cold tumors treated from 2015 to 2021 with ICI combinations in early CT at VHIO were reviewed. Clinico-pathological data and anti-tumor activity were extracted from a prospective database. ORR was defined as per RECIST v1.1 and clinical benefit rate (CBR) as complete/partial response (CR/PR) + stable disease (SD) for ≥ 4 months (m). Kaplan Meier estimates of progression-free survival (PFS) and overall survival (OS) were calculated and a Cox model according to LIPI (Lung Immune Prognostic Index = baseline LDH and derived neutrophil to lymphocyte ratio) was constructed. Immune-related adverse events (irAE) were classified as per CTCAE v.4.03. Hyperprogressive disease (HPD) was evaluated using RECIST v1.1 (Matos et al, 2020). Results: Out of 97 pts, median age was 62y, 61% had ECOG 0 and 29.8% had LIPI 0 (good prognostic score). Most pts had microsatellite stable (MSS) colorectal cancer (60.8%) or ovarian cancer (14.4%). Regimens included anti-PD1/L1 + another ICI in 69% (most commonly anti-LAG3 [26,8%] and CD40 agonist [20.9%]), anti-PD1/L1 + other molecule in 21.7% (most commonly SHP2 inhibitor [33.3%] and anti p53-HDM2 [28.5%]) and bispecific antibodies in 9.3% (anti-PD1/L1 + anti-LAG3 or CD137 agonist). No patient achieved a response. CBR was 15.3% (11 pts with MSS colorectal cancer, 2 ovarian cancer, 1 olfactory neuroblastoma, 1 paraganglioma). 33 pts (34%) presented irAE, 15 pts (15.5%) had irAE ≥ G2, 4 pts (4.1%) had G3 irAE (dry mouth, hypertransaminasemia, myocarditis and neutrophils count decreased) and 1 patient (1%) had G4 hyperglicemia. 58 pts (59.7%) had progressive disease (PD) as best response, 19 of these pts (32.7%) presented irAE. Overall, 20 pts (20.6%) met definition of HPD, representing 34.4% of pts with PD as best response. Median PFS for overall and CBR population were 1.9 m (CI95% 1.7-2.0) and 5.9 m (5.4-NR), respectively. Median OS for overall population was 7.6 m (5.9-9.5), with a trend for improved OS if LIPI good score vs. others (12.6 m vs. 6.2 m, hazard ratio 1.9, (CI 95% 1.1-3.3), p = 0.02). Among hyperprogressors, median OS was 5.33 m (3.39 - NR) and significantly worse LIPI scores (intermediate [1] or poor [2]) were observed as compared to pts with CBR (75% vs 53.3% p = 0.001). Conclusions: ICI combinations demonstrated very limited activity in pts with unselected cold tumors. However, the risk for irAE and HPD remain substantial. Further drug-biomarker co-development strategies are urgently needed to increase the risk benefit ratio for these pts.

ItRECIST adapted efficacy assessment in solid tumors treated with intratumoral immunotherapy

2557

Background: The development of human intratumoral therapy (HIT-IT) has surged as a promising strategy to overcome resistance to checkpoint inhibitors (CPI), promoting a stronger tumor-specific immune response while reducing systemic exposure. A broad variety of agents (i.e: oncolytic viruses, toll-like receptors agonists) administered both in superficial- and deep-seated lesions are being currently tested in clinical trials (CT). Due to the local intervention on tumors, radiological assessment by standard RECIST is challenging and new methods of response that capture and integrate the local and systemic response to HIT-IT are needed. We aimed to evaluate the feasibility and clinical utility of itRECIST (Goldmacher et al., 2020) in patients (pts) treated with HIT-IT in early phase CT. Methods: Retrospective analysis of a cohort of pts with different solid tumor types enrolled in CT including HIT-IT in our institution between August’18 and January’21. Clinical characteristics were collected. Efficacy in target-injected (T-I) and target-non-injected (T-NI) lesions was assessed by objective response rate (ORR) and disease control rate (DCR), as per itRECIST. Overall disease ORR and DCR were assessed per RECIST 1.1/iRECIST. Treatment-related adverse events (TRAEs) were assessed with CTCAE v.5.0. ORR was calculated with Clopper-Pearson method. Survival analysis was made using Kaplan-Meier method. Results: A total of 37 pts were included. Median age was 66 years, 19 pts (51%) were male, all pts had ECOG 0-1. 24 pts (65%) were CPI-naïve. Median previous lines of therapy was 2 (range [r]: 0-11). All pts (100%) received minimum 1 dose of HIT-IT. 6 pts (16%) were treated with monotherapy and 31 pts (84%) in combination with CPI. Median HIT-IT and CPI doses administered were 4 (r: 1-9) and 2 (r: 1-13), respectively. Injected lesions: cutaneous (16.2%), subcutaneous (21.6%), lymph node (32.4%), liver (29.7%). Median size of T-I lesions was 40 mm (r: 19-260). At data cutoff, 32 pts were evaluable. Median follow-up was 14.4 weeks (r: 1.0-81.1). Per RECIST 1.1, overall ORR was 6% (95% CI, 5-7) and DCR was 38% (95% CI, 21-56). Per itRECIST, ORR was 19% (95% CI, 7-36) and DCR was 63% (95% CI, 44-79) in T-I lesions (n = 32), and 10% (95% CI, 22-27) and 48% (95% CI, 29-67) in T-NI lesions (n = 29). Mean decrease in responding T-I and T-NI lesions was -47% (r: -21 to -100) and -41% (r: -26 to -59), respectively. No non-target (NT) lesion was injected. Median progression-free survival was 7.4 weeks (95% CI, 6.6 – 8.2). Median overall survival was 10.0 months (95% CI, 2.3 – 17.7). Incidence of TRAE was 58% (grade 1-2 IT-related pyrexia 43%; grade 3-4, 5%). No treatment-related deaths were recorded. Conclusions: ItRECIST is feasible to implement and adds precision to the radiological assessment of local and distant anti-tumor activity of HIT-IT. No safety issues were detected in our cohort.

Lenvatinib in Patients With Advanced Grade 1/2 Pancreatic and Gastrointestinal Neuroendocrine Tumors: Results of the Phase II TALENT Trial (GETNE1509)

PURPOSE

Approved systemic therapies for advanced gastroenteropancreatic neuroendocrine tumors (GEP-NETs) have shown limited capacity to reduce tumor burden and no antitumor activity after progression to targeted agents (TAs). We investigated the efficacy and safety of lenvatinib in patients with previously treated advanced GEP-NETs.

PATIENTS AND METHODS

This was a multicenter, single-arm, open-label, phase II trial with two parallel cohorts (ClinicalTrials.gov identifier: NCT02678780) involving 21 institutions in 4 European countries. Eligible patients had histologically confirmed advanced grade 1-2 pancreatic (panNET) or GI (GI-NET) NETs with documented tumor progression after treatment with a TA (panNET) or somatostatin analogs (GI-NET). Patients were treated with lenvatinib 24 mg once daily until disease progression or treatment intolerance. The primary end point was overall response rate by central radiology review. Secondary end points included progression-free survival, overall survival, duration of response, and safety.

RESULTS

Between September 2015 and March 2017, a total of 111 patients were enrolled, with 55 (panNET) and 56 (GI-NET) patients in each cohort. The median follow-up was 23 months. The overall response rate was 29.9% (95% CI, 21.6 to 39.6): 44.2% (panNET) and 16.4% (GI-NET). The median (range) duration of response was 19.9 (8.4-30.8) and 33.9 (10.6-38.3) months in the panNET and GI-NET groups, respectively. The median progression-free survival was 15.7 months (95% CI, 14.1 to 19.5). The most common adverse events were fatigue, hypertension, and diarrhea; 93.7% of patients required dose reductions or interruptions.

CONCLUSION

We report the highest centrally confirmed response reported to date with a multikinase inhibitor in advanced GEP-NETs, with a particularly strong response in the panNET cohort. This study provides novel evidence for the efficacy of lenvatinib in patients with disease progression following treatment with other TAs, suggesting the potential value of lenvatinib in the treatment of advanced GEP-NETs.

Efficacy and safety of pembrolizumab in patients with advanced mesothelioma in the open-label, single-arm, phase 2 KEYNOTE-158 study

BACKGROUND

Malignant pleural mesothelioma (MPM) has few treatment options. Pembrolizumab showed preliminary clinical benefit in programmed death ligand 1 (PD-L1)-positive MPM. We evaluated the efficacy and safety of pembrolizumab monotherapy in patients with previously treated MPM irrespective of PD-L1 status in the KEYNOTE-158 study.

METHODS

The ongoing open-label, multicohort, single-arm, phase 2 KEYNOTE-158 study enrolled eligible adults (≥18 years) with MPM who had progression on or intolerance to standard therapy, Eastern Cooperative Oncology Group performance status 0-1, and biomarker-evaluable tumour samples. Individuals were enrolled from 35 academic facilities and community-based institutions across 14 countries in Australia, North America, Europe, and Asia. Participants received pembrolizumab 200 mg intravenously every 3 weeks for up to 35 cycles. The primary efficacy endpoint was objective response per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1, based on radiological imaging every 9 weeks for the first year of the study and every 12 weeks thereafter and assessed by independent central review. Efficacy and safety were analysed in all patients who received at least one dose of pembrolizumab. This trial is registered with ClinicalTrials.gov, NCT02628067.

FINDINGS

Patients were enrolled in the MPM cohort between Feb 9, 2016, and Aug 16, 2016. As of June 27, 2019, 118 patients had been enrolled and received at least one dose of pembrolizumab. Ten (8% [95% CI 4-15]) patients had an objective response. Median duration of objective response was 14·3 months (range 4·0 to 33·9+), and 60% of objective responses were ongoing at 12 months. Objective responses were observed in six (8%) of 77 patients with PD-L1-positive MPM (median response duration 17·7 months [range 5·8 to 33·9+]) and four (13%) of 31 patients with PD-L1-negative MPM (10·2 months [4·0-16·6]). Median overall survival was 10·0 months (95% CI 7·6-13·4) and median progression-free survival was 2·1 months (2·1-3·9). Treatment-related adverse events occurred in 82 (69%) of 118 patients and serious adverse events that were considered to be treatment-related occurred in 14 (12%) of 118 patients. 19 (16%) patients had grade 3-4 treatment-related events, and most common of these were colitis (three patients), hyponatraemia (three), and pneumonitis (two). One patient died from treatment-related apnoea. By the end of the trial, 113 (96%) patients had discontinued pembrolizumab and progressive disease was the most common reason for discontinuation.

INTERPRETATION

Pembrolizumab showed durable antitumour activity and manageable toxicity in patients with advanced MPM, regardless of PD-L1 status. Our data support the programmed death 1 (PD-1) and PD-L1 pathway as a potential therapeutic target in some patients with previously treated mesothelioma but biomarkers that can effectively identify such patients are yet to be elucidated.

FUNDING

Merck Sharp & Dohme Corp, a subsidiary of Merck & Co, Inc, Kenilworth, NJ, USA.

A CT-based Radiomics Signature Is Associated with Response to Immune Checkpoint Inhibitors in Advanced Solid Tumors

Background Reliable predictive imaging markers of response to immune checkpoint inhibitors are needed. Purpose To develop and validate a pretreatment CT-based radiomics signature to predict response to immune checkpoint inhibitors in advanced solid tumors. Materials and Methods In this retrospective study, a radiomics signature was developed in patients with advanced solid tumors (including breast, cervix, gastrointestinal) treated with anti-programmed cell death-1 or programmed cell death ligand-1 monotherapy from August 2012 to May 2018 (cohort 1). This was tested in patients with bladder and lung cancer (cohorts 2 and 3). Radiomics variables were extracted from all metastases delineated at pretreatment CT and selected by using an elastic-net model. A regression model combined radiomics and clinical variables with response as the end point. Biologic validation of the radiomics score with RNA profiling of cytotoxic cells (cohort 4) was assessed with Mann-Whitney analysis. Results The radiomics signature was developed in 85 patients (cohort 1: mean age, 58 years ± 13 [standard deviation]; 43 men) and tested on 46 patients (cohort 2: mean age, 70 years ± 12; 37 men) and 47 patients (cohort 3: mean age, 64 years ± 11; 40 men). Biologic validation was performed in a further cohort of 20 patients (cohort 4: mean age, 60 years ± 13; 14 men). The radiomics signature was associated with clinical response to immune checkpoint inhibitors (area under the curve [AUC], 0.70; 95% CI: 0.64, 0.77; P < .001). In cohorts 2 and 3, the AUC was 0.67 (95% CI: 0.58, 0.76) and 0.67 (95% CI: 0.56, 0.77; P < .001), respectively. A radiomics-clinical signature (including baseline albumin level and lymphocyte count) improved on radiomics-only performance (AUC, 0.74 [95% CI: 0.63, 0.84; P < .001]; Akaike information criterion, 107.00 and 109.90, respectively). Conclusion A pretreatment CT-based radiomics signature is associated with response to immune checkpoint inhibitors, likely reflecting the tumor immunophenotype. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Summers in this issue.

Phase I, first-in-human study of futibatinib, a highly selective, irreversible FGFR1-4 inhibitor in patients with advanced solid tumors

BACKGROUND

Futibatinib is an oral, irreversible, highly selective fibroblast growth factor receptor (FGFR)1-4 inhibitor with potent preclinical activity against tumors harboring FGFR aberrations. This first-in-human, phase I dose-escalation trial (NCT02052778) evaluates the safety and pharmacokinetics/pharmacodynamics of futibatinib in advanced solid tumors.

PATIENTS AND METHODS

Following a standard 3+3 dose-escalation design, eligible patients with advanced solid tumors refractory to standard therapies received 8-200 mg futibatinib three times a week (t.i.w.) or 4-24 mg once daily (q.d.).

RESULTS

A total of 86 patients were enrolled in the nine t.i.w. (n = 42) and five q.d. cohorts (n = 44); 71 patients (83%) had tumors harboring FGF/FGFR aberrations. Three of nine patients in the 24-mg q.d. cohort experienced dose-limiting toxicities, including grade 3 increases in alanine transaminase, aspartate transaminase, and blood bilirubin (n = 1 each). The maximum tolerated dose (MTD) was determined to be 20 mg q.d.; no MTD was defined for the t.i.w. schedule. Across cohorts (n = 86), the most common treatment-emergent adverse events (TEAEs) were hyperphosphatemia (59%), diarrhea (37%), and constipation (34%); 48% experienced grade 3 TEAEs. TEAEs led to dose interruptions, dose reductions, and treatment discontinuations in 55%, 14%, and 3% of patients, respectively. Pharmacokinetics were dose proportional across all q.d. doses but not all t.i.w. doses evaluated, with saturation observed between 80 and 200 mg t.i.w. Serum phosphorus increased dose dependently with futibatinib on both schedules, but a stronger exposure-response relationship was observed with q.d. dosing, supporting 20 mg q.d. as the recommended phase II dose (RP2D). Overall, partial responses were observed in five patients [FGFR2 fusion-positive intrahepatic cholangiocarcinoma (n = 3) and FGFR1-mutant primary brain tumor (n = 2)], and stable disease in 41 (48%).

CONCLUSIONS

Futibatinib treatment resulted in manageable safety, pharmacodynamic activity, and preliminary responses in patients with advanced solid tumors. The results of this phase I dose-escalation trial support 20 mg q.d. futibatinib as the RP2D.

CLINICAL TRIAL REGISTRATION

FOENIX-101 (ClinicalTrials.gov, NCT02052778).

The PALBONET Trial: A Phase II Study of Palbociclib in Metastatic Grade 1 and 2 Pancreatic Neuroendocrine Tumors (GETNE-1407)

LESSONS LEARNED

Palbociclib demonstrated no detectable activity in molecularly unselected and heavily pretreated patients with advanced grade 1/2 pancreatic neuroendocrine tumors. Predictive biomarkers that improve patient selection should be investigated in future studies of palbociclib.

BACKGROUND

Palbociclib, a CDK4/6 inhibitor, has shown in vitro activity in pancreatic neuroendocrine tumor (pNET) cell lines. Here we prospectively assessed the activity and safety of palbociclib in monotherapy in metastatic refractory pNETs.

METHODS

This was a nonrandomized, open-label, phase II study of patients with metastatic grade (G)1/2 pNETs recruited from 10 centers in Spain. Palbociclib 125 mg was orally administered once daily for 21 of 28 days until disease progression or unacceptable toxicity.

RESULTS

Twenty-one patients were included; 52.4% were men, and median age was 57.4 years (range, 37.4-73.4). Patients had previously received a median of three prior lines of systemic therapy (range, 1-10) for advanced disease (somatostatin analogues, 71.4%; sunitinib, 81.0%; everolimus, 47.6%; chemotherapy, 47.6%). Nineteen patients were evaluated for objective response rate (ORR), with a median follow-up of 12.4 months (range, 7.53-19.33). No objective and confirmed responses were observed (0%); 11 (57.9%) patients had stable disease, and 6 of them lasted more than 6 months; 8 (42.1%) patients had disease progression as best response. Median progression-free survival (PFS) was 2.6 months (95% confidence interval [CI], 0-14.4) and median overall survival (OS) was 18.7 months (95% CI, 7.4-29.9; Fig. 1). Most frequent toxicities of any grade were asthenia (76.2%), neutropenia (42.9%), diarrhea (33.3%), and nausea (33.3%). Five (23.8%) patients developed G3-4 neutropenia and two (9.5%) patients developed G3-4 thrombocytopenia.

CONCLUSION

Lack of activity was observed with palbociclib as a single agent in molecularly unselected and heavily pretreated patients with advanced G1/2 pNETs.

Abstract 2953: Adapting a molecular prescreening program to detect notch pathway alterations in the context of early drug development

Introduction: Gene alterations in NOTCH signaling pathway have a prevalence ranging from &lt;1% to 13% across tumor types. Efforts in adapting molecular prescreening programs to emerging biomarkers are critical in the context of early clinical trials. The aim of this retrospective study is to assess the prevalence of NOTCH pathway alterations and compare the results of our two institutional panels with public databases (AACR Project GENIE) in order to guide drug development efforts and basket trials.

Methods: From Jan/2017 to Dec/2018, 1,697 patients (pts) had their FFPE tumor samples (either primary or metastasis) analyzed for mutations (mut) using a custom developed Amplicon-Seq panel of 59 cancer-related genes (including NOTCH1 [hotspots 5% exon coverage] and NOTCH4 [hotspots 3% exon coverage]) that was run in Illumina MiSeq (v1). Additionally, 502 samples were analyzed for Copy Number Alterations (CNA) using a panel of 44 genes (including NOTCH1-4) using NanoString nCounter (copy number between 4-6 copies were validated by FISH). From Jun/2018 to Jun/2019 an expanded NOTCH Amplicon-Seq panel v2 (including additional exons in NOTCH1 plus NOTCH2 and NOTCH3 hotspots regions) replaced the prior v1 panel and 618 samples were sequenced.

Results: Colorectal cancer (CRC) (n= 404 [24%]; n=241 [39 %]) and breast cancer (BC) (n=283 [17%]; n= 194 [31%]) were the most frequent tumor types for v1 and v2 panel cohorts, respectively. NOTCH1-4 mut were detected in 11 cases (0.64%). The highest rate of NOTCH pathway alterations (NOTCH1-4 mut plus CN gain or loss) was detected in BC (n=14 [7.7%]) with a clear enrichment in triple negative subtype. Higher prevalence of NOTCH1-4 mut was detected using expanded v2 panel, with 17 NOTCH1-4 mut cases (2.75%). Head & neck (H&N) (n=3 [5%]); BC (n=6 [3%]); and CRC (n=6 [2.5%]) were most common tumors. From all NOTCH1-4 gene mut detected, 8 were known actionable oncogenic driver mut and 9 were variants of unknown significance. When comparing our latest v2 results with GENIE database (mostly large NGS panels with exon capture), we found a similar prevalence in NOTCH1-4 mut in BC and CRC, but lower prevalence was seen in H&N, biliary and gastric tumors. We enrolled 4 pt in clinical trials with NOTCH inhibitors (3 NOTCH1 actionable mut pt (0.48%), 1 NOTCH3 actionable mut pt (0.16%).

Conclusion: Institutional efforts to increase coverage of NOTCH pathway genes improved the detection of actionable NOTCH1-4 mut. Differences in prevalence as compared to GENIE dataset may be attributed to the small number of samples tested with our v2 panel and larger panels covering all exons of NOTCH1-4 genes in GENIE cohort. Therefore, we keep evolving our NOTCH prescreening program for clinical trial enrichment.

Citation Format: Analía Azaro, Susana Aguilar, Zighereda Ogbah, Omar Saavedra, María Vieito, Ignacio Matos, Irene Braña, Enriqueta Felip, Joan Carles, Lorena Fariñas, Elena Elez, Teresa Macarulla, Cristina Saura, Rodrigo Dienstmann, Elena Garralda, Ana Vivancos. Adapting a molecular prescreening program to detect notch pathway alterations in the context of early drug development [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2953.

Abstract A19: A phase 1, multicenter, dose-escalation study of PRN1371, an irreversible covalent FGFR1-4 kinase inhibitor, in patients with advanced solid tumors including metastatic urothelial carcinoma (mUC)

Background: FGFR inhibition is a promising and clinically proven therapeutic approach in a number of solid tumors where genetic alterations of FGFR drive oncogenesis. PRN1371 is a highly selective oral, irreversible inhibitor of FGFR1-4 that exhibits high potency in cancer cell lines harboring FGFR alterations, including mutations and fusions.

Methods: Part A of this phase 1 open-label, multicenter clinical trial explored ascending doses of PRN1371 in adult patients with advanced solid tumors who had received at least one prior treatment for recurrent, metastatic, and/or locally advanced disease, and for whom no standard therapy options were anticipated to result in a durable remission. The primary objectives were to investigate the safety and tolerability and determine the maximum tolerated dose (MTD). Secondary objectives included determination of the pharmacokinetic (PK) profile. The trial employed a “3 + 3” design, where cohorts of three patients are studied at each dose level until additional patients need to be added to better assess safety. PRN1371 was dosed once or twice daily in continuous, 28-day cycles until disease progression. Elevated serum phosphorus, a known effect of systemic FGFR inhibition, was managed with oral phosphate-binding medications and a low phosphate diet, with dose interruptions and use of acetazolamide if certain thresholds were exceeded.

Results: In part A, PRN1371 was administered to 36 patients in cohorts at doses of 15mg, 20mg, 25mg, and 35mg QD as well as BID doses of 15mg and 25mg. The drug has been generally well tolerated. The most common side effect observed was hyperphosphatemia, which was generally managed by administration of phosphate binders, and there were no treatment-related adverse events leading to study drug discontinuation. Five of 36 patients reported treatment-related serious adverse events (SAEs). PRN1371 was well absorbed, exhibited moderate PK variability with minimal accumulation, and was approximately dose proportional between 15 and 35mg doses. Exposure of parent drug in urine exceeded the cellular IC90 at all dose levels, which may be particularly relevant for localized bladder cancer. Part B of the study has been initiated, which will enroll patients with metastatic urothelial cell carcinoma (mUC) with FGFR1, 2, 3, or 4 genetic alterations.

Citation Format: Sarina A. Piha-Paul, Cinta Hierro, Ignacio Matos, Valentina Boni, Noah Hahn, Rhonda Bitting, Todd Bauer, Aggarwal Rahul, Funda Meric-Bernstam, Steven Gourlay, Timothy D. Owens, Ken Brameld, Ann Neale, Richard Schwartz, Steve Murray, Sibel Ucpinar, Peter Foote, Eleni Venetsanakos, Josep Tabernero. A phase 1, multicenter, dose-escalation study of PRN1371, an irreversible covalent FGFR1-4 kinase inhibitor, in patients with advanced solid tumors including metastatic urothelial carcinoma (mUC) [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2019 May 18-21; Denver, CO. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(15_Suppl):Abstract nr A19.

Atypical patterns of response and progression in the era of immunotherapy combinations

In the immunoncology era, an acceleration of tumor growth upon immune checkpoint inhibitors (ICI), defined as hyperprogressive disease (HPD) has been observed across different cancers. Although in non-small-cell lung cancer, most of the available evidence regarding HPD has been reported for patients treated with single agent PD-1 and PD-L1 inhibitors, in retrospective series a variable proportion of patients receiving ICI combinations also experienced HPD. Similarly, the shape of survival curves and the progression rates in clinical trials testing combinations of PD-1/PD-L1 inhibitors and anti-CTLA-4 agents suggest the occurrence of HPD. Few data are available regarding pseudoprogression upon ICI combinations. However, considering that pseudoprogression has been reported for anti-PD-1/PD-L1 agents and for CTLA-4 inhibitors separately, it is likely that it may occur also upon combinations of these two classes of drugs.

Final results from the phase I study expansion cohort of the selective FGFR inhibitor Debio 1,347 in patients with solid tumors harboring an FGFR gene fusion

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Background: Debio 1347 is a selective oral inhibitor of FGFR 1-3 tyrosine kinases. It exhibited high antitumor activity in in vitro and in vivo tumor models with FGFR1-3 gene fusions. Here we report the results of the expansion portion of a Phase 1 study of advanced solid tumors patients (pts) harboring an FGFR1-3 gene fusion. Methods: Pts with advanced refractory solid tumors harboring an FGFR1-3 gene fusion were enrolled. Based on results from the dose escalation portion, pts received Debio1347 80 mg once daily (qd) in 28-day cycles. Pharmacokinetics (PK) and pharmacodynamics were evaluated. The data cut-off was October 8, 2019. Results: Among 18 pts enrolled, 5 had primary brain tumors (PBT), 5 had cholangiocarcinoma, 2 had urothelial cancer, 2 had colon cancer, 1 patient each lung neoplasm, gastric cancer, endometrial cancer and squamous cell carcinoma of the chest wall. Tumors harbored fusions with FGFR1 (n = 1), FGFR2 (n = 8), and FGFR3 (n = 9). All had prior systemic therapy (median 3 lines; range 1-4). The most common treatment emergent adverse events were fatigue (50%), hyperphosphatemia (44.4%), anemia (38.9%), alopecia (33.3%), nausea (33.3%), vomiting (33.3%), constipation (33.3%), and palmar-plantar erythrodysesthesia syndrome (22.2%). Blurred vision was reported in 1 pt. There were no findings on ocular exams compatible with retinal detachment. No grade 3 AE related to study drug were reported. One patient needed dose reduction due to grade 2 nails toxicity. In PK analysis, plasma steady-state was rapidly achieved and serum phosphate increase correlated with Debio 1347 plasma exposure, confirming target engagement at 80 mg qd. Median follow-up was 18 weeks. Partial responses were observed in 3 pts harboring an FGFR2 fusion: 1 out of 2 colon cancer and 2 out 5 cholangiocarcinoma. Median duration of response was 16.1 weeks (range: 8.4-22.8+). Overall disease control was observed in 11 out of 14 pts without PBT (79%). Median PFS was 18.3 weeks. No signs of activity were observed in the 5 patients with PBT, all with an FGFR3-TACC3 fusion. Conclusions: Debio 1347 at the recommended dose of 80 mg qd was generally well tolerated and showed signs of activity in solid tumors harboring an FGFR fusion. The FUZE phase 2 clinical trial of Debio 1347 is recruiting FGFR fusion-positive advanced solid tumors irrespectively of tumor histology, excluding PBT. Clinical trial information: NCT01948297 .

Hyperprogression and Immunotherapy: Fact, Fiction, or Alternative Fact?

Immunotherapy (IO) has altered the therapeutic landscape for multiple cancers. There are emerging data from retrospective studies on a subset of patients who do not benefit from IO, instead experiencing rapid progression with dramatic acceleration of disease trajectory, termed 'hyperprogressive disease' (HPD). The incidence of HPD ranges from 4% to 29% from the studies reported. Biological basis and mechanisms of HPD are currently being elucidated, with one theory involving the Fc region of antibodies. Another group has shown EGFR and MDM2/MDM4 amplifications in patients with HPD. This phenomenon has polarized oncologists who debate that this could still reflect the natural history of the disease. Thus, prospective studies are urgently needed to confirm the underlying biology, predict patients who are susceptible to HPD, and determine the modality of therapy post progression.

Pembrolizumab After Two or More Lines of Previous Therapy in Patients With Recurrent or Metastatic SCLC: Results From the KEYNOTE-028 and KEYNOTE-158 Studies

INTRODUCTION

Pembrolizumab has shown clinical benefit in patients with previously treated recurrent or metastatic SCLC in the phase 1b multicohort study KEYNOTE-028 (NCT02054806) and the phase 2 multicohort study KEYNOTE-158 (NCT02628067). We present a pooled analysis of patients from KEYNOTE-028 and KEYNOTE-158 who had received two or more lines of previous therapy for SCLC.

METHODS

Eligible patients were aged 18 years and above, had histologically or cytologically confirmed incurable recurrent or metastatic SCLC, had an Eastern Cooperative Oncology Group performance status of 1 and below, and had received two or more lines of previous therapy. Patients in KEYNOTE-028 were required to have a programmed death ligand 1 (PD-L1)-positive tumor. Patients received pembrolizumab (10 mg/kg every 2 weeks in KEYNOTE-028 or 200 mg every 3 weeks in KEYNOTE-158) for up to 2 years. The primary end point was objective response rate per Response Evaluation Criteria in Solid Tumors version 1.1, which is presented here per independent review.

RESULTS

Eighty-three patients who had received two or more lines of previous therapy (KEYNOTE-028, n = 19; KEYNOTE-158, n = 64) were included. Median follow-up duration was 7.7 (range, 0.5-48.7) months. Objective response rate was 19.3% (95% confidence interval: 11.4-29.4); two patients had complete response (one with a PD-L1-positive tumor), and 14 patients had partial response (13 with PD-L1-positive tumors). The median duration of response was not reached (range, 4.1‒35.8+ mo; plus sign indicates ongoing response); 61% of responders had responses lasting 18 months or longer. Fifty-one patients (61.4%) experienced any-grade treatment-related adverse events; eight patients (9.6%) had grade 3 or higher events.

CONCLUSIONS

Pembrolizumab exhibited durable antitumor activity in a subset of patients with recurrent or metastatic SCLC who had undergone two or more previous lines of therapy, regardless of PD-L1 expression. Pembrolizumab was well tolerated.

Abstract B050: Validation of body mass index (BMI) as a prognostic factor in patients (pts) treated with immune checkpoint inhibitors (ICI) across multiple cancer types (CT) and the impact of confounding factors (CF)

Introduction: Obesity results in PD1-mediated T-cell dysfunction in preclinical models and improved outcomes from ICI. We wanted to validate this clinical association in a prospective cohort of pts receiving PD1/L1 inhibitors across multiple CT and investigate the potential impact of CF, such as age and concomitant medications (CM) that may interact with obesity. Methods: Clinicopathological data from 310 pts treated with ICI at VHIO phase 1 Unit from Aug'12 to Jul'18 were investigated. Frequent CM included metformin (M), statins (S) and others. Associations between different variables and progression-free survival (PFS) were assessed with univariable and multivariate Cox regression models and survival data were calculated by the Kaplan-Meier method. Tumor types were stratified by proven PD1/L1 inhibitor efficacy versus unknown PD1/L1 sensitivity. Results: Out of 310 pts, median age was 59.8 years (y), 54.2% were male and most frequent tumor type was melanoma (19.4%) and lung (13.2%). In univariate models, pts with BMI&gt;25 kg/m2 (n=147, 47%) had increased PFS (3.5 months [m], CI95% 2.8-5.5) as compared to those with BMI&lt;25 kg/m2 (2.3m, CI95% 1.9-3.7, HR=0.73, p=0.02). Overweight and obese pts were older and more often received S and M than those with normal BMI or underweight. Pts exposed to S (n=50, 16%) had increased PFS (6.3 m, CI95% 3.7-9.5) as compared to those without S use (2.7m, CI95% 2.1-3.5, HR=0.63, p=0.03). Other CM had no impact on pts outcomes. In a multivariable model adjusting for age, tumor type, S and M use, increased BMI had no longer a significant impact on PFS (HR=0.83 [CI95% 0.63-1.11], p=0.21), and only age remained a signficant prognostic fator (10-y increase in age, HR=0.86 [CI95% 0.77-0.95], p=0.005). Conclusion: In univariate models, increased BMI is associated with prolonged PFS in pts receiving ICI. However, after adjustment for CF such as age and CM, the association loses statistical significance. Larger randomized cohorts need to be investigated before conclusive statements on obesity as a determinant of benefit with ICI.

Citation Format: Analía Azaro, Alejandra Ivars, Ignacio Matos, Omar Saavedra, Itziar Gardeazabal, Juan Martin-Liberal, Cinta Hierro, María Vieito, Irene Braña, Cristina Viaplana, Guillermo Villacampa, Gemma Sala, María Alsina, Ana Callejo, Helena Verdaguer, Guillem Aegiles, Ana Oaknin, Eva Muñoz, Rodrigo Dienstmann, Elena Garralda. Validation of body mass index (BMI) as a prognostic factor in patients (pts) treated with immune checkpoint inhibitors (ICI) across multiple cancer types (CT) and the impact of confounding factors (CF) [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr B050. doi:10.1158/1535-7163.TARG-19-B050

Early evolutionary divergence between papillary and anaplastic thyroid cancers

Background

Papillary thyroid cancer (PTC) is the most common thyroid carcinoma and exhibits an almost uniformly good prognosis, while anaplastic thyroid cancer (ATC) is less frequent and is one of the most aggressive cancers usually resistant to conventional treatment. Current hypothesis posits that ATC derives from PTC through the progressive acquisition of a discrete number of genomic alterations and implies that the mutational landscape of ATC resembles that of PTC. However, the clinical behaviour of ATC and PTC is radically different. We decided to address the disconnection between the clinical behaviour of ATC and PTC and the proposed model of the progressive development of ATC from PTC.

Patients and methods

We carried out exome sequencing of DNA from 14 ATC specimens including three cases of concomitant ATC and PTC as well as their corresponding normal DNA from 14 patients. The sequencing results were validated using droplet digital PCR. We carried out immunohistochemistry and immunofluorescence studies of the concomitant ATC and PTC cases. In addition, we integrated our sequencing results with the existing TCGA data.

Results

Most of the somatic mutations identified in the ATC component differed from the ones in PTC in the cases of concomitant ATC and PTC. The trunks of the phylogenetic trees representing the somatic mutations were short with long branches. In one case of concomitant PTC and ATC specimens, we observed an infiltration of PTC cells within the ATC component. Moreover, we integrated our results with data obtained from TCGA and observed that the most frequent mutations found in ATC presented high cancer cell fraction values and were significantly different from the PTC ones.

Conclusion

ATC diverge from PTC early in tumour development and both tumour types evolve independently. Our work allows the understanding of the relationship between ATC and PTC facilitating the clinical management of these malignancies.

Identification of Expression Profiles Defining Distinct Prognostic Subsets of Radioactive-Iodine Refractory Differentiated Thyroid Cancer from the DECISION Trial

Several biomarkers have been suggested to have prognostic value in differentiated thyroid carcinomas (DTC) with no validation in the refractory setting, including all tumor subtypes. We aim to correlate RNA expression profiles with survival based on patients included in the DECISION trial. We obtained 247 samples from the 417 patients included in the DECISION study and performed RNAseq analysis (77 million paired-end reads for each sample on HiSeq2000). After quality control, 125 samples were included in the secondary analysis and mapped against the human reference genome (GRCh38) with STAR (v2.5.1b) using ENCODE parameter. Survival analysis was calculated using the Kaplan-Meier method and log-rank test was used for statistical comparison. In this post hoc analysis, we identified three groups of tumors based on their gene expression profile: BRAF-like, RAS-like, and non-BRAF-non-RAS-like (NoBRaL). No significant correlation with sorafenib responders was observed. However, we identified a statistically significant correlation between the RNA-expression profiles and progression-free survival. The BRAF-like profile had a significantly better outcome compared with RAS-like and NoBRaL (11.8, 6.2, and 5.5 months, respectively) [HR: 0.31, 95% confidence interval (CI), 0.17-0.60; P < 0.001 and HR: 0.36 (95% CI, 0.21-0.63); P < 0.001] and HR: 0.36 (95% CI, 0.21-0.63; P < 0.001) and maintained significance as an independent prognostic factor for overall survival in the multivariate analysis for papillary thyroid cancers. To our knowledge, this is the first comprehensive RNA-seq analysis of all histologic subtypes of DTC. The RNA expression profiles identified may suggest a new prognostic parameter to be considered before recommendation of systemic therapies or the design of stratification factors for future clinical trials.