Case-control study assessing the impact of COVID19 in advanced kidney cancer patients treated with antiangiogenics or immunotherapy: the COVID-REN study

BACKGROUND

Cancer is a risk factor for developing severe COVID19. Additionally, SARS-CoV2 has a special tropism for renal cells and complications like thrombosis or cytokine storm could be enhanced by standard treatments in kidney cancer (i.e., antiangiogenics or immunotherapy). Thus, understanding the impact of COVID19 in patients with this tumor is key for their correct management.

METHODS

We designed a retrospective case-control study comparing the outcome of three groups of advanced kidney cancer patients on systemic treatment: cohort A (developed COVID19 while on antiangiogenics), cohort B (developed COVID19 while on immunotherapy) and cohort C (non-infected). Matching factors were age, gender, and treatment.

RESULTS

95 patients were recruited in 16 centers in Spain from September 2020 to May 2021. Finally, 85 were deemed as eligible (23 cohort A, 21 cohort B, 41 cohort C). Patients with COVID required more dose interruptions (25 vs. six) and hospitalizations (10 vs. none) than those without COVID (both p = 0.001). No difference between cohorts A and B was observed regarding hospitalization or length of stay. No ICU admission was registered and one patient in cohort B died due to COVID19. Regarding cancer evolution, three patients in cohort A presented progressive disease after COVID19 compared to two in cohort B. One case in cohort B, initially deemed as stable disease, achieved a partial response after COVID19.

CONCLUSIONS

Kidney cancer patients who developed COVID19 while on systemic therapy required more treatment interruptions and hospitalizations than those non-infected. However, no significant impact on cancer outcome was observed. Also, no difference was seen between cases on antiangiogenics or immunotherapy.

MEK inhibitor sensitivity in BRAF fusion-driven prostate cancer

PURPOSE

The identification of subpopulations harboring druggable targets has become a major step forward in the subclassification of solid tumors into small groups suitable for specific therapies. BRAF fusions represent a paradigm of uncommon and targetable oncogenic events and have been widely correlated to the development of specific malignancies. However, they are only present in a limited frequency across most common tumor types. At this regard, we performed a genomic screening aimed to identifying rare variants associated to advanced prostate cancer development.

METHODS

Tumoral tissue genomic screening of 41 patients developing advanced prostate cancer was performed at our center as part of the GETHI XX study. The project, sponsored by the Spanish Collaborative Group in Rare Cancers (GETHI), aims to analyze the molecular background of rare tumors and to discover unfrequent molecular variants in common tumors.

RESULTS

Here we present the clinical outcome and an in-deep molecular analysis performed in a case harboring a SND1-BRAF fusion gene. The identification of such rearrangement in a patient refractory to standard therapies led to the administration of trametinib (MEK inhibitor). Despite unsensitive to standard therapies, the patient achieved a dramatic response to trametinib. A comprehensive study of the tumor demonstrated this event to be a trunk alteration with higher expression of MEK in areas of tumor invasion.

CONCLUSIONS

Our study describes the patient-driven discovery of the first BRAF fusion-driven prostate cancer effectively treated with trametinib. Consequently, MAPK pathway activation could define a new subtype of prostate cancer susceptible to a tailored management.

Combination of radiomic and biomarker signatures as exploratory objective in a phase II trial with intratumoral BO-112 plus pembrolizumab for advanced melanoma

TPS9586

Background: Intratumoral immunotherapies are gaining interest in oncology, particularly in melanoma. These therapies, however, have faced some issues. For instance, standard response criteria do not accurately describe tumor burden, and responses may differ for injected/non injected lesions. Besides, target lesions may become non evaluable. Biomarkers provide interesting information for these therapies. In addition, some radiomic signatures have been associated with CD-8 infiltration. BO-112 is a double stranded synthetic RNA formulated with polyethyleneimine (PEI) that mimics a viral infection, mobilizing the immune system and changing tumor microenvironment. Clinical data are available from a first-in-human study, which showed ORR of 11% and DCR of 46% in patients who had developed progressive disease on immunotherapy. In patients with melanoma, this ORR was 20%. A phase 2 clinical study of BO-112 with pembrolizumab in patients with liver metastases from digestive tumors is ongoing. Both studies brought up data regarding how some biomarkers are increased after a single dose of BO-112 and correlated with responses. In this phase II study in patients with pretreated melanoma (NCT04570332), we will prospectively assess CD-8 and PD-L1 by immunohistochemistry, which will be compared with multi-parametric radiologic findings and correlated with clinical benefit. In addition, retrospective DNA sequencing will be performed. This kind of exploratory analysis in intratumoral immunotherapies might be key to identify predictive and prognostic factors. Methods: Phase 2, single arm, open label study of BO-112 with pembrolizumab in patients with advanced melanoma. BO-112 is administered once weekly (QW) in 1 to 8 tumor lesions, total dose 1-2 mg (depending on the number of injected lesions), for the first 7 weeks and then once every three weeks (Q3W); pembrolizumab 200 mg will be administered Q3W. Key eligibility criteria: advanced cutaneous or mucosal melanoma; patients must have progressed on or after treatment with an antiPD-1/L1 mAb; at least one measurable lesion amenable for weekly IT injection. Primary efficacy variable is ORR by RECIST 1.1, assessed by independent central radiologist (QUIBIM Precision platform). A 1-sided alpha of 4.19% and power of 81.8% are used. If less than 8 patients out of 40 have ORR, the study will not meet the statistical bar. Secondary endpoints include clinical activity by RECIST1.1 and iRECIST, overall survival, safety and PKs. Exploratory objectives include itRECIST and evaluation of CD-8 and PD-L1 expression by immunohistochemistry (Pangaea laboratory), which will be correlated with radiomic signatures (first order and second order) from standard-of-care computed tomography (CT) images. Enrollment is open and 1 of planned 40 patients has been enrolled. Nineteen sites are planned to participate. Clinical trial information: NCT04570332.

Abstract 5288: Mechanisms of resistance to FGFR inhibitors in urothelial cancer cell lines and patients harboring FGFR3 alterations and strategies to overcome it

Introduction

The Fibroblast Growth Factor Receptor (FGFR) has become a key target in urothelial cancer. The FGFR inhibitor (FGFRi) erdafitinib has been approved for clinical use and many others are in development. Unfortunately, responses have shown to last short. Thus, it is urgently required to identify the underlying mechanisms of resistance and establish strategies to overcome it.

We designed a comprehensive in vitro study in FGFR3-altered urothelial cancer cell lines after acquiring resistance to FGFRis. In parallel, we monitored the clinical and molecular evolution (through tumor biopsies and ctDNA) of three patients treated with FGFRi at our institution.

Experimental Procedures

Drug sensitivity to FGFRi (Erdafitinib and AZD4547) was evaluated in bladder cancer cell lines harboring FGFR3 point mutations (pS249C) or rearrangements (FGFR3/BAIAP2L1 or TACC3). After performing 7-days proliferation assays, cell lines showing nM-range sensitivity were long-term treated with high concentrations of both compounds to induce therapeutic resistance.

Cell lysates were collected and protein arrays (Human Phospho-RTK and Kinases Array, R&D Systems) were used for the identification of proteins involved in the desensitization to FGFRi. Later, cell lines were treated with selective inhibitors of such kinases.

Regarding patients, after providing written consent, tumor tissue was collected retrospectively from the initial diagnosis and prospectively in any new tumor resection performed in daily practice. ctDNA from peripheral blood was also periodically extracted.

Results & Conclusions

Protein arrays showed an overactivation of phosphorylated forms of proteins involved in PI3K (EGFR and AKT, 4 and 9-fold increase) and MAPK pathways or proteins related to signal transduction (PLCγ, 80-fold increase, among others). When treated with trametinib, IGF1Ri, ipatasertib, everolimus or erlotinib, only trametinib and IGF1Ri demonstrated significant activity in cell cultures.

Three patients were included in the clinical cohort of our study (2 males, 1 female). All harbored the mutation p.S249C and initially achieved a partial response. Multiple biopsies (baseline and at tumor progression) were analyzed in case 1, showing a secondary mutation in FGFR3 and molecular alterations in EGFR and IGFR pathways as potential mechanisms of resistance, matching the results previously observed in in vitro models. Studies of the other 2 cases are ongoing and will be presented at the meeting.

Combination of FGFRi with additional TKIs could improve the efficacy of these drugs. Further studies and validation in clinical trials are required.

Citation Format: Sergio Ruiz-Llorente, Elena Fernández-Sevillano, Paloma Navarro, Juan Francisco Rodríguez-Moreno, Arantzazu Barquín-García, Sandra Amarilla-Quintana, Mónica Yagüe-Fernández, Juan María Roldan-Romero, Raquel Martín, Cristina Rodriguez-Antona, Jesús García-Donas. Mechanisms of resistance to FGFR inhibitors in urothelial cancer cell lines and patients harboring FGFR3 alterations and strategies to overcome it [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 5288.