Impact of Clonal Hematopoiesis-Associated Mutations in Phase I Patients Treated for Solid Tumors: An Analysis of the STING Trial.

PURPOSE: With liquid biopsy's widespread adoption in oncology, an increased number of clonal hematopoiesis-associated mutations (CHm) have been identified in patients with solid tumors. However, its impact on patient outcomes remains unclear. This study aimed to analyze and describe CHm in a cohort of phase I patients. METHODS: Retrospective data collection from medical records and molecular profiles (Foundation One Liquid CDx Assay) was performed before first study drug administration at the Drug Development Department of Gustave Roussy (France) within the STING trial (ClinicalTrials.gov identifier: NCT04932525). CHm prevalence was assessed using any and ≥1% variant allele frequency (VAF) in epigenetic modifier genes (DNMT3A, TET2, and ASXL1). RESULTS: From January 2021 to December 2022, 255 patients were enrolled in a phase I clinical trial. A total of 55% were male, with a median age of 62 years (24-86). Principal tumor locations were GI (27%) and genitourinary (21%). Overall, 104 patients (41%) had at least one CHm in liquid biopsy, with 55 patients (22%) having a VAF of ≥ 1%. The most frequent mutation was DNMT3A 73% at any VAF (n = 76) and 22% at 1% VAF (n = 23). Median progression-free survival (PFS) and overall survival were 3.8 months (m) for the CHm group versus 3.2 m for nonclonal hematopoiesis (CH; P = .08) and 18.26 m CHm versus 15.8 m non-CH (P = .9), respectively. PFS increased in the CHm population treated with targeted therapy (hazard ratio, 0.6 [95% CI, 0.42 to 0.84]; P = .004). CONCLUSION: CHm was commonly found in patients with solid tumors treated in phase I trials, with a prevalence of 41% in our cohort. The most frequently mutated gene was DNMT3A. The presence of CHm had no impact on the population of patients treated in the phase I trials.

Genomic landscape of liquid biopsy mutations in TP53 and DNA damage genes in cancer patients.

Next-generation sequencing (NGS) assays based on plasma cell-free DNA (cfDNA) are increasingly used for clinical trials inclusion. Their optimized limit of detection applied to a large number of genes leads to the identification of mutations not confirmed in tissue. It becomes essential to describe the characteristics and consequences of these liquid biopsy-only mutations. In the STING protocol (Gustave Roussy, NCT04932525), 542 patients with advanced solid cancer had cfDNA-based and tissue-based NGS analysis (performed by FoundationOne® Liquid CDx and FoundationOne CDx™, respectively). Mutations identified in the liquid biopsy but not in the paired tissue were considered as liquid biopsy-only mutations irrespective of their variant allelic frequency (VAF). Out of 542 patients, 281 (51.8%) harbored at least one liquid biopsy-only mutation. These patients were significantly older, and more heavily pretreated. Liquid biopsy-only mutations occurring in TP53, and in DDR genes (ATM, CHEK2, ATR, BRCA2, and BRCA1) accounted for 90.8% of all the mutations. The median VAF of these mutations was generally low (0.37% and 0.40% for TP53 and DDR genes respectively). The variant type repartition depended on the gene. Liquid biopsy-only mutations affected hotspot in TP53 codon 273, 125, 195, 176, 237 or 280 and ATM codon 2891 and 3008. In a subset of 37 patients, 75.0%, 53.5% and 83.3% of the liquid biopsy-only mutations occurring respectively in ATM, TP53, and CHEK2 were confirmed in the matching whole blood sample. Although liquid biopsy-only mutations makes the interpretation of liquid biopsy results more complex, they have distinct characteristics making them more easily identifiable.

Homologous recombination deficiency (HRD) testing on cell-free tumor DNA from peritoneal fluid.

BACKGROUND: Knowing the homologous recombination deficiency (HRD) status in advanced epithelial ovarian cancer (EOC) is vital for patient management. HRD is determined by BRCA1/BRCA2 pathogenic variants or genomic instability. However, tumor DNA analysis is inconclusive in 15-19% of cases. Peritoneal fluid, available in > 95% of advanced EOC cases, could serve as an alternative source of cell-free tumor DNA (cftDNA) for HRD testing. Limited data show the feasibility of cancer panel gene testing on ascites cfDNA but no study, to date, has investigated HRD testing. METHODS: We collected ascites/peritoneal washings from 53 EOC patients (19 from retrospective cohort and 34 from prospective cohort) and performed a Cancer Gene Panel (CGP) using NGS for TP53/HR genes and shallow Whole Genome Sequencing (sWGS) for genomic instability on cfDNA. RESULTS: cfDNA was detectable in 49 out of 53 patients (92.5%), including those with limited peritoneal fluid. Median cfDNA was 3700 ng/ml, with a turnaround time of 21 days. TP53 pathogenic variants were detected in 86% (42/49) of patients, all with HGSOC. BRCA1 and BRCA2 pathogenic variants were found in 14% (7/49) and 10% (5/49) of cases, respectively. Peritoneal cftDNA showed high sensitivity (97%), specificity (83%), and concordance (95%) with tumor-based TP53 variant detection. NGS CGP on cftDNA identified BRCA2 pathogenic variants in one case where tumor-based testing failed. sWGS on cftDNA provided informative results even when tumor-based genomic instability testing failed. CONCLUSION: Profiling cftDNA from peritoneal fluid is feasible, providing a significant amount of tumor DNA. This fast and reliable approach enables HRD testing, including BRCA1/2 mutations and genomic instability assessment. HRD testing on cfDNA from peritoneal fluid should be offered to all primary laparoscopy patients.

Circulating tumor DNA landscape and prognostic impact of acquired resistance to targeted therapies in cancer patients: a national center for precision medicine (PRISM) study.

BACKGROUND: Despite the effectiveness of the various targeted therapies currently approved for solid tumors, acquired resistance remains a persistent problem that limits the ultimate effectiveness of these treatments. Polyclonal resistance to targeted therapy has been described in multiple solid tumors through high-throughput analysis of multiple tumor tissue samples from a single patient. However, biopsies at the time of acquired resistance to targeted agents may not always be feasible and may not capture the genetic heterogeneity that could exist within a patient. METHODS: We analyzed circulating tumor DNA (ctDNA) with a large next-generation sequencing panel to characterize the landscape of secondary resistance mechanisms in two independent prospective cohorts of patients (STING: n = 626; BIP: n = 437) with solid tumors who were treated with various types of targeted therapies: tyrosine kinase inhibitors, monoclonal antibodies and hormonal therapies. RESULTS: Emerging alterations involved in secondary resistance were observed in the plasma of up 34% of patients regardless of the type of targeted therapy. Alterations were polyclonal in up to 14% of patients. Emerging ctDNA alterations were associated with significantly shorter overall survival for patients with some tumor types. CONCLUSION: This comprehensive landscape of genomic aberrations indicates that genetic alterations involved in secondary resistance to targeted therapy occur frequently and suggests that the detection of such alterations before disease progression may guide personalized treatment and improve patient outcome.

Clinical utility of plasma ctDNA sequencing in metastatic urothelial cancer.

BACKGROUND: Genomic stratification may help improve the management of patients with metastatic urothelial cancer (mUC), given the recent identification of targetable alterations. However, the collection of tissue samples remains challenging. Here, we assessed the clinical utility of plasma circulating tumour DNA (ctDNA) sequencing in these patients. METHODS: Patients with mUC were prospectively enroled in the STING trial (NCT04932525), in which ctDNA was profiled using the Foundation One Liquid CDx Assay (324 genes, blood tumour mutational burden [bTMB], microsatellite instability status). Each genomic report was reviewed by a multidisciplinary tumor board (MTB). RESULTS: Between January 2021 and June 2022, 140 mUC patients underwent molecular profiling. The median time to obtain the assay results was 20 days ((confidence interval) CI95%: [20,21]). The ctDNA analysis reproduced the somatic genomic landscape of previous tissue-based cohorts. Concordance for serial ctDNA samples was strong (r = 0.843 CI95%: [0.631-0.938], p < 0.001). At least one actionable target was detected in 63 patients (45%) with a total of 35 actionable alterations, including bTMB high (≥10 mutations/Mb) (N = 39, 21.1%), FGFR3 (N = 20, 10.8%), and Homologous recombination deficiency (HRD) alterations (N = 14, 7.6%). MTB recommended matched therapy in 63 patients (45.0%). Eight patients (5.7%) were treated, with an overall response rate of 50% (CI95%: 15.70-84.30) and a median progression-free survival (PFS) of 5.2 months (CI95%: 4.1 - NR). FGFR3 alterations were associated with a shorter PFS in patients treated with immunotherapy. CONCLUSION: Overall, we demonstrated that genomic profiling with ctDNAs in mUC is a reliable and feasible approach for the timely initiation of genotype-matched therapies.

Targetable Molecular Alterations in the Treatment of Biliary Tract Cancers: An Overview of the Available Treatments.

Biliary tract cancers (BTCs) are rare tumours, most often diagnosed at an unresectable stage, associated with poor prognosis, with a 5-year survival rate not exceeding 10%. Only first- and second-line treatments are well codified with the combination of cisplatin-gemcitabine chemotherapy and immunotherapy followed by 5-FU and oxaliplatin chemotherapy, respectively. Many studies have shown that BTC, and more particularly intrahepatic cholangiocarcinoma (iCCA), have a high rate of targetable somatic alteration. To date, the FDA has approved several drugs. Ivosidenib targeting IDH1 mutations, as well as futibatinib and pemigatinib targeting FGFR2 fusions, are approved for pre-treated advanced CCA. The combination of dabrafenib and trametinib are approved for BRAFV600E mutated advanced tumours, NTRK inhibitors entrectinib and larotrectinib for tumours bearing NTRK fusion and prembrolizumab for MSI-H advanced tumours, involving a small percentage of BTC in these three settings. Several other potentially targetable alterations are found in BTC, such as HER2 mutations or amplifications or KRASG12C mutations and mutations in genes involved in DNA repair mechanisms. This review aims to clarify the specific diagnostic modalities for gene alterations and to summarize the results of the main trials and developments underway for the management of advanced BTC with targetable alterations.

Resistance to Selective FGFR Inhibitors in FGFR-Driven Urothelial Cancer.

Several fibroblast growth factor receptor (FGFR) inhibitors are approved or in clinical development for the treatment of FGFR-driven urothelial cancer, and molecular mechanisms of resistance leading to patient relapses have not been fully explored. We identified 21 patients with FGFR-driven urothelial cancer treated with selective FGFR inhibitors and analyzed postprogression tissue and/or circulating tumor DNA (ctDNA). We detected single mutations in the FGFR tyrosine kinase domain in seven (33%) patients (FGFR3 N540K, V553L/M, V555L/M, E587Q; FGFR2 L551F) and multiple mutations in one (5%) case (FGFR3 N540K, V555L, and L608V). Using Ba/F3 cells, we defined their spectrum of resistance/sensitivity to multiple selective FGFR inhibitors. Eleven (52%) patients harbored alterations in the PI3K-mTOR pathway (n = 4 TSC1/2, n = 4 PIK3CA, n = 1 TSC1 and PIK3CA, n = 1 NF2, n = 1 PTEN). In patient-derived models, erdafitinib was synergistic with pictilisib in the presence of PIK3CA E545K, whereas erdafitinib-gefitinib combination was able to overcome bypass resistance mediated by EGFR activation. SIGNIFICANCE: In the largest study on the topic thus far, we detected a high frequency of FGFR kinase domain mutations responsible for resistance to FGFR inhibitors in urothelial cancer. Off-target resistance mechanisms involved primarily the PI3K-mTOR pathway. Our findings provide preclinical evidence sustaining combinatorial treatment strategies to overcome bypass resistance. See related commentary by Tripathi et al., p. 1964. This article is featured in Selected Articles from This Issue, p. 1949.

Liquid Biopsies for Circulating Tumor DNA Detection May Reveal Occult Hematologic Malignancies in Patients With Solid Tumors.

PURPOSE: High-risk clonal hematopoiesis (CH) is frequently incidentally found in patients with solid tumors undergoing plasma cell-free DNA sequencing. Here, we aimed to determine if the incidental detection of high-risk CH by liquid biopsy may reveal occult hematologic malignancies in patients with solid tumors. MATERIALS AND METHODS: Adult patients with advanced solid cancers enrolled in the Gustave Roussy Cancer Profiling study (ClinicalTrials.gov identifier: NCT04932525) underwent at least one liquid biopsy (FoundationOne Liquid CDx). Molecular reports were discussed within the Gustave Roussy Molecular Tumor Board (MTB). Potential CH alterations were observed, and patients referred to hematology consultation in the case of pathogenic mutations in JAK2, MPL, or MYD88, irrespective of the variant allele frequency (VAF), or in DNMT3A, TET2, ASXL1, IDH1, IDH2, SF3B1, or U2AF1 with VAF ≥ 10%, while also considering patient cancer-related prognosis. TP53 mutations were discussed case-by-case. RESULTS: Between March and October 2021, 1,416 patients were included. One hundred ten patients (7.7%) carried at least one high-risk CH mutation: DNMT3A (n = 32), JAK2 (n = 28), TET2 (n = 19), ASXL1 (n = 18), SF3B1 (n = 5), IDH1 (n = 4), IDH2 (n = 3), MPL (n = 3), and U2AF1 (n = 2). The MTB advised for hematologic consultation in 45 patients. Overall, 9 patients of 18 actually addressed had confirmed hematologic malignancies that were occult in six patients: two patients had myelodysplastic syndrome, two essential thrombocythemia, one a marginal lymphoma, and one a Waldenström macroglobulinemia. The other three patients were already followed up in hematology. CONCLUSION: The incidental findings of high-risk CH through liquid biopsy may trigger diagnostic hematologic tests and reveal an occult hematologic malignancy. Patients should have a multidisciplinary case-by-case evaluation.

RET-MAP: An International Multicenter Study on Clinicobiologic Features and Treatment Response in Patients With Lung Cancer Harboring a RET Fusion.

INTRODUCTION: Nearly 1% to 2% of NSCLCs harbor RET fusions. Characterization of this rare population is still incomplete. METHODS: This retrospective multicenter study included patients with any-stage RET positive (RET+) NSCLC from 31 cancer centers. Molecular profiling included DNA/RNA sequencing or fluorescence in situ hybridization analyses. Clinicobiological features and treatment outcomes (per investigator) with surgery, chemotherapy (CT), immune checkpoint blockers (ICBs), CT-ICB, multityrosine kinase inhibitors, and RET inhibitors (RETis) were evaluated. RESULTS: For 218 patients included between February 2012 and April 2022, median age was 63 years, 56% were females, 93% had adenocarcinoma, and 41% were smokers. The most frequent fusion partner was KIF5B (72%). Median tumor mutational burden was 2.5 (range: 1-4) mutations per megabase, and median programmed death-ligand 1 expression was 10% (range: 0%-55%). The most common metastatic sites were the lung (50%), bone (43%), and pleura (40%). Central nervous system metastases were found at diagnosis of advanced NSCLC in 21% of the patients and at last follow-up or death in 31%. Overall response rate and median progression-free survival were 55% and 8.7 months with platinum doublet, 26% and 3.6 months with single-agent CT, 46% and 9.6 months with CT-ICB, 23% and 3.1 months with ICB, 37% and 3 months with multityrosine kinase inhibitor, and 76% and 16.2 months with RETi, respectively. Median overall survival was longer in patients treated with RETi versus no RETi (50.6 mo [37.7-72.1] versus 16.3 mo [12.7-28.8], p < 0.0001). CONCLUSIONS: Patients with RET+ NSCLC have mainly thoracic and bone disease and low tumor mutational burden and programmed death-ligand 1 expression. RETi markedly improved survival, whereas ICB may be active in selected patients.

Next-Generation Sequencing on Circulating Tumor DNA in Advanced Solid Cancer: Swiss Army Knife for the Molecular Tumor Board? A Review of the Literature Focused on FDA Approved Test.

FDA-approved next-generation sequencing assays based on cell-free DNA offers new opportunities in a molecular-tumor-board context thanks to the noninvasiveness of liquid biopsy, the diversity of analyzed parameters and the short turnaround time. It gives the opportunity to study the heterogeneity of the tumor, to elucidate complex resistance mechanisms and to adapt treatment strategies. However, lowering the limit of detection and increasing the panels' size raise new questions in terms of detection of incidental germline alterations, occult malignancies and clonal hematopoiesis of indeterminate potential mutations. In this review, after a technological discussion and description of the common problematics encountered, we establish recommendations in properly using these FDA-approved tests in a molecular-tumor-board context.

Clinical Utility and Outcomes Impact of Crystal Digital PCR of Sensitizing and Resistance EGFR Mutations in Patients With Advanced Non-Small Cell Lung Cancer.

BACKGROUND: EGFRm represent 15% of advanced NSCLC in European patients. LB for molecular profiling offers a non-invasive alternative to tissue. cdPCR is a high-sensitive and low-cost LB to detect molecular alterations. We aimed to describe cdPCR clinical utility for EGFRm detection in advanced NSCLC. METHODS: Prospective blood sample collection in patients with advanced NSCLC harbouring EGFRm either at diagnosis, under response or at PD between January 16 and September 20 at Gustave Roussy. LB was performed by cdPCR (Stilla): sensitizing (exon19; exon21 [p.L858R]) and exon 20 p.T790M resistance EGFRm. We defined high tumour burden (high-TB) as >2 metastatic sites. We analysed EGFRm detection by cdPCR and its correlation with progression-free and overall survival (PFS, OS). RESULTS: A total of 252 blood samples were collected in 140 patients. At baseline (n=25), sensitizing EGFRm were detected in 64% of samples, 88% in patients with high-TB (n=8) and 40% among those with intracranial/intrathoracic isolated lesions (n=5). At PD to tyrosine-kinase inhibitors (TKI) (n=117), detection rate (sensitizing EGFRm) was 56%; 30% in patients with intracranial/thoracic isolated lesions (n=37) vs. 67% in those with high-TB (n=63). At PD to first/second generation TKI (n=81), the p.T790M mutation was found in 22% (18/81); detection rate was 9% for intracranial/thoracic (n=23) vs. 32% for high-TB (n=41) cases. The clearance of EGFRm allelic frequency was correlated with radiological response. The absence of EGFRm detection at TKI-failure was associated with longer OS (39.1 vs. 18.4 months; P=.02). CONCLUSIONS: cdPCR is a sensitive LB for sensitizing and resistance EGFRm detection. cdPCR positivity was more likely observed in systemic PD cases with high-TB. It is a low-cost EGFRm detecting approach to guide treatment in NSCLC, however metastatic profile should be taken into account.

Meningeal "Lazarus Response" to Lorlatinib in a ROS1-Positive NSCLC Patient Progressing to Entrectinib.

BACKGROUND: ROS1 tyrosine kinase inhibitors (TKIs) have showed activity and efficacy in ROS1-rearranged non-small cell lung cancer (NSCLC). In the clinical practice, besides the utilization of crizotinib, less is known about the best treatment strategies involving additional, new-generation TKIs for the sequential treatment of ROS1-positive NSCLC patients. CASE PRESENTATION: A patient suffering from a ROS1-rearranged lung adenocarcinoma, after receiving cisplatin-pemetrexed chemotherapy, was treated with entrectinib, a new-generation ALK/ROS1/NTRK inhibitor. After 16 months, central nervous system (CNS) metastases appeared, without extra-cerebral disease progression. Stereotactic brain radiotherapy was performed and entrectinib was maintained, due to the global systemic disease control. Approximately one month after radiotherapy, thoracic and meningeal progressions were detected, the latter highly symptomatic with neurocognitive disorders, visual hallucinations and worsening of psycho-motor impairment. A lumbar puncture was positive for tumor cells and for an EZR-ROS1 fusion. The administration of lorlatinib (a third-generation ALK/ROS1 inhibitor) prompted an extremely rapid improvement of clinical conditions, anticipating the positive results observed at radiologic evaluation that confirmed the disease response still ongoing after nine months since treatment start. DISCUSSION: With the expanding availability of targeted agents with differential activity on resistance mechanism and on CNS disease, choosing wisely the best treatment strategies is pivotal to assure the best clinical outcomes in oncogene-addicted NSCLC patients. Here we have reported lorlatinib reverted an almost fatal meningeal carcinomatosis developing during entrectinib in a ROS1-positive NSCLC patient.

Chronic Plasma Exposure to Kinase Inhibitors in Patients with Oncogene-Addicted Non-Small Cell Lung Cancer.

Kinase inhibitors (KI) have dramatically improved the outcome of treatment in patients with non-small cell lung cancer (NSCLC), which harbors an oncogene addiction. This study assesses KI plasma levels and their clinical relevance in patients chronically exposed to KIs. Plasma samples were collected in NSCLC patients receiving erlotinib, gefitinib, osimertinib, crizotinib, or dabrafenib (with or without trametinib) for at least three months between November 2013 and February 2019 in a single institution. KI drug concentrations were measured by ultra-performance liquid chromatography coupled with tandem mass spectrometry and compared to published data defining optimal plasma concentration. The main outcome was the rate of samples with suboptimal KI plasma concentrations. Secondary outcomes included its impact on T790M mutation emergence in patients receiving a first-generation epidermal growth factor receptor (EGFR) KI. Fifty-one samples were available from 41 patients with advanced NSCLC harboring driver genetic alterations, including EGFR, v-Raf murine sarcoma viral oncogene homolog B (BRAF), anaplastic lymphoma kinase (ALK) or ROS proto-oncogene 1 (ROS1), and who had an available evaluation of chronic KI plasma exposure. Suboptimal plasma concentrations were observed in 51% (26/51) of cases. In EGFR-mutant cases failing first-generation KIs, EGFR exon 20 p.T790M mutation emergence was detected in 31% (4/13) of samples in optimal vs. none in suboptimal concentration (0/5). Suboptimal plasma concentrations of KIs are frequent in advanced NSCLC patients treated with a KI for at least three months and might contribute to treatment failure.

Transcriptome profiling of gastric-type endocervical adenocarcinomas identifies key signaling pathways for tumor progression.

OBJECTIVE: Gastric-type endocervical carcinoma is a rare entity of carcinoma of the cervix. In contrast to the intestinal type, the gastric type is not related to Human Papilloma Virus (HPV) infection and has been reported to be much more aggressive than the usual type. Oncogenic pathways involved in this poor-prognosis phenotype are largely unexplored. METHODS: We compared activation of the main signaling pathways involved in cancer progression between the intestinal- (n = 5), gastric- (n = 6) and usual-type (n = 6) adenocarcinomas of the cervix using a targeted transcriptomic approach (expression of 770 genes) on FFPE samples. RESULTS: We identified a gene-expression signature composed of 11 genes that allows the classification of these endocervical carcinoma as three distinct molecular entities. There were similarities between mucinous endocervical carcinomas (gastric and intestinal types) despite difference in pathogenesis related to HPV infection. Among HPV-related endocervical carcinoma, the intestinal type could be molecularly distinguished from the usual type by high expression of EIF2AK3 and low expression of PPFIBP2 genes, supporting its classification as a distinct entity. Overexpression of TAL1 and S1PR1 genes were characteristic of the gastric type. The usual type was characterized by high expression of occludin and VAV3 genes. Tight junction disruptions might play an essential role in the metastatic potential of mucinous endocervical carcinoma with concomitant loss of OCLN and claudin 4 proteins. An overexpression of NTRK1 transcript was observed in mucinous endocervical carcinomas when compared to the usual type. CONCLUSIONS: This transcriptomic study identified a signature that supports the classification of endocervical carcinomas as three distinct entities: usual-, intestinal- and gastric-type. It also points out to disruption of tight junctions as a potential mechanism of metastatic dissemination of these rare tumors.