BID expression determines the apoptotic fate of cancer cells after abrogation of the spindle assembly checkpoint by AURKB or TTK inhibitors.

BACKGROUND: Drugs targeting the spindle assembly checkpoint (SAC), such as inhibitors of Aurora kinase B (AURKB) and dual specific protein kinase TTK, are in different stages of clinical development. However, cell response to SAC abrogation is poorly understood and there are no markers for patient selection. METHODS: A panel of 53 tumor cell lines of different origins was used. The effects of drugs were analyzed by MTT and flow cytometry. Copy number status was determined by FISH and Q-PCR; mRNA expression by nCounter and RT-Q-PCR and protein expression by Western blotting. CRISPR-Cas9 technology was used for gene knock-out (KO) and a doxycycline-inducible pTRIPZ vector for ectopic expression. Finally, in vivo experiments were performed by implanting cultured cells or fragments of tumors into immunodeficient mice. RESULTS: Tumor cells and patient-derived xenografts (PDXs) sensitive to AURKB and TTK inhibitors consistently showed high expression levels of BH3-interacting domain death agonist (BID), while cell lines and PDXs with low BID were uniformly resistant. Gene silencing rendered BID-overexpressing cells insensitive to SAC abrogation while ectopic BID expression in BID-low cells significantly increased sensitivity. SAC abrogation induced activation of CASP-2, leading to cleavage of CASP-3 and extensive cell death only in presence of high levels of BID. Finally, a prevalence study revealed high BID mRNA in 6% of human solid tumors. CONCLUSIONS: The fate of tumor cells after SAC abrogation is driven by an AURKB/ CASP-2 signaling mechanism, regulated by BID levels. Our results pave the way to clinically explore SAC-targeting drugs in tumors with high BID expression.

Real-world safety and effectiveness of maintenance niraparib for platinum-sensitive recurrent ovarian cancer: A GEICO retrospective observational study within the Spanish expanded-access programme.

AIM: To describe patient characteristics, effectiveness and safety in a real-world population treated with niraparib in the Spanish expanded-access programme. PATIENTS AND METHODS: This retrospective observational study included women with platinum-sensitive recurrent high-grade serous ovarian cancer who received maintenance niraparib within the Spanish niraparib expanded-access programme. Eligible patients had received ≥2 previous lines of platinum-containing therapy, remained platinum-sensitive after the penultimate line of platinum and had responded to the most recent platinum-containing therapy. Niraparib dosing was at the treating physician's discretion (300 mg/day fixed starting dose or individualised starting dose [ISD] according to baseline body weight and platelet count). Safety, impact of dose adjustments, patient characteristics and effectiveness were analysed using data extracted from medical records. RESULTS: Among 316 eligible patients, 80% had BRCA wild-type tumours and 66% received an ISD. Median niraparib duration was 7.8 months. The most common adverse events typically occurred within 3 months of starting niraparib. Median progression-free survival was 8.6 (95% confidence interval [CI] 7.6-10.0) months. One- and 2-year overall survival rates were 86% (95% CI 81-89%) and 65% (95% CI 59-70%), respectively. Dose interruptions, dose reductions, haematological toxicities and asthenia/fatigue were less common with ISD than fixed starting dose niraparib, but progression-free survival was similar irrespective of dosing strategy. Subsequent therapy included platinum in 71% of patients who received further treatment. CONCLUSION: Outcomes in this large real-world dataset of niraparib-treated patients are consistent with phase III trials, providing reassuring evidence of the tolerability and activity of niraparib maintenance therapy for platinum-sensitive recurrent ovarian cancer. GOV REGISTRATION: NCT04546373.

Trastuzumab deruxtecan in patients with central nervous system involvement from HER2-positive breast cancer: The DEBBRAH trial.

BACKGROUND: Trastuzumab deruxtecan (T-DXd) has shown durable antitumor activity in pretreated patients with HER2-positive advanced breast cancer (ABC), but its efficacy has not yet been evaluated in patients with active brain metastases (BMs). DEBBRAH aims to assess T-DXd in patients with HER2-positive or HER2-low ABC and central nervous system involvement. METHODS: This ongoing, five-cohort, phase II study (NCT04420598) enrolled patients with pretreated HER2-positive or HER2-low ABC with stable, untreated, or progressing BMs, and/or leptomeningeal carcinomatosis. Here, we report findings from HER2-positive ABC patients with non-progressing BMs after local therapy (n = 8; cohort 1), asymptomatic untreated BMs (n = 4; cohort 2), or progressing BMs after local therapy (n = 9; cohort 3). Patients received 5.4 mg/kg T-DXd intravenously once every 21 days. The primary endpoint was 16-week progression-free survival (PFS) for cohort 1 and intracranial objective response rate (ORR-IC) for cohorts 2 and 3. RESULTS: As of October 20, 2021, 21 patients received T-DXd. In cohort 1, 16-week PFS rate was 87.5% (95%CI, 47.3-99.7; P < .001). ORR-IC was 50.0% (95%CI, 6.7-93.2) in cohort 2 and 44.4% (95%CI, 13.7-78.8; P < .001) in cohort 3. Overall, the ORR-IC in patients with active BMs was 46.2% (95%CI, 19.2-74.9). Among patients with measurable intracranial or extracranial lesions at baseline, the ORR was 66.7% (12 out of 18 patients; 95%CI, 41.0-86.7), 80.0% (95%CI, 28.4-99.5) in cohort 1, 50.0% (95%CI, 6.7-93.2) in cohort 2, and 66.7% (95%CI, 29.9-92.5) in cohort 3. All responders had partial responses. The most common adverse events included fatigue (52.4%; 4.8% grade ≥3), nausea (42.9%; 0% grade ≥3), neutropenia (28.6%; 19% grade ≥3), and constipation (28.6%; 0% grade ≥3). Two (9.5%) patients suffered grade 1 interstitial lung disease/pneumonitis. CONCLUSIONS: T-DXd showed intracranial activity with manageable toxicity and maintained the quality of life in pretreated HER2-positive ABC patients with stable, untreated, or progressing BMs. Further studies are needed to validate these results in larger cohorts.

Challenging Endocrine Sensitivity of Hormone Receptor-Positive/HER2-Negative Advanced Breast Cancer with the Combination of Eribulin and Endocrine Therapy: The REVERT Study.

BACKGROUND: Luminal advanced breast cancer (ABC) patients eventually progress on endocrine therapy. REVERT aimed to explore whether eribulin could restore endocrine sensitivity in a randomized, non-comparative phase II trial. METHODS: Aromatase inhibitor (AI)-resistant patients with luminal ABC were randomized 1:1 to receive eribulin +/- AI. Patients were stratified by prior cyclin-dependent kinases 4/6 inhibitor (CDK4/6i) treatment. The primary endpoint was an investigator-assessed overall response rate (ORR) according to RECIST version 1.1 in the eribulin + AI arm. An interim analysis was planned with 11 evaluable patients according to a two-stage Simon design. RESULTS: Twenty-two patients were enrolled (15 eribulin + AI arm; 7 eribulin arm). The trial was terminated early in March 2021, with eight (36.4%) patients still on treatment. ORR was 26.7% in the eribulin + AI arm (95% CI, 7.8-55.1%; p = 0.0541). In the eribulin arm, two (28.6%) patients had an objective response (95% CI, 3.7-71.0%). The difference between the study arms was not significant (p = 0.918). The addition of AI to eribulin also failed to show improvement in other efficacy endpoints. A significant interaction between the treatment arm and previous CDK4/6i treatment was observed for ORR (p = 0.018) and progression-free survival (p = 0.084). Overall, the toxicity profile was consistent with the known safety profile of eribulin. No treatment-related deaths were reported. CONCLUSION: Eribulin + AI does not seem to improve outcomes compared with eribulin monotherapy in patients with AI-resistant luminal ABC. This chemo-endocrine approach deserves further investigation after progression to CDK4/6i-based therapy.

Multiplex Detection of Clinically Relevant Mutations in Liquid Biopsies of Cancer Patients Using a Hybridization-Based Platform.

BACKGROUND: With the advent of precision oncology, liquid biopsies are quickly gaining acceptance in the clinical setting. However, in some cases, the amount of DNA isolated is insufficient for Next-Generation Sequencing (NGS) analysis. The nCounter platform could be an alternative, but it has never been explored for detection of clinically relevant alterations in fluids. METHODS: Circulating-free DNA (cfDNA) was purified from blood, cerebrospinal fluid, and ascites of patients with cancer and analyzed with the nCounter 3 D Single Nucleotide Variant (SNV) Solid Tumor Panel, which allows for detection of 97 driver mutations in 24 genes. RESULTS: Validation experiments revealed that the nCounter SNV panel could detect mutations at allelic fractions of 0.02-2% in samples with ≥5 pg mutant DNA/µL. In a retrospective analysis of 70 cfDNAs from patients with cancer, the panel successfully detected EGFR, KRAS, BRAF, PIK3CA, and NRAS mutations when compared with previous genotyping in the same liquid biopsies and paired tumor tissues [Cohen kappa of 0.96 (CI = 0.92-1.00) and 0.90 (CI = 0.74-1.00), respectively]. In a prospective study including 91 liquid biopsies from patients with different malignancies, 90 yielded valid results with the SNV panel and mutations in EGFR, KRAS, BRAF, PIK3CA, TP53, NFE2L2, CTNNB1, ALK, FBXW7, and PTEN were found. Finally, serial liquid biopsies from a patient with NSCLC revealed that the semiquantitative results of the mutation analysis by the SNV panel correlated with the evolution of the disease. CONCLUSIONS: The nCounter platform requires less DNA than NGS and can be employed for routine mutation testing in liquid biopsies of patients with cancer.

Multiplex RNA-based detection of clinically relevant MET alterations in advanced non-small cell lung cancer.

MET inhibitors have shown activity in non-small-cell lung cancer patients (NSCLC) with MET amplification and exon 14 skipping (METΔex14). However, patient stratification is imperfect, and thus, response rates have varied widely. Here, we studied MET alterations in 474 advanced NSCLC patients by nCounter, an RNA-based technique, together with next-generation sequencing (NGS), fluorescence in situ hybridization (FISH), immunohistochemistry (IHC), and reverse transcriptase polymerase chain reaction (RT-PCR), exploring correlation with clinical benefit. Of the 474 samples analyzed, 422 (89%) yielded valid results by nCounter, which identified 13 patients (3%) with METΔex14 and 15 patients (3.5%) with very-high MET mRNA expression. These two subgroups were mutually exclusive, displayed distinct phenotypes and did not generally coexist with other drivers. For METΔex14, 3/8 (37.5%) samples positive by nCounter tested negative by NGS. Regarding patients with very-high MET mRNA, 92% had MET amplification by FISH and/or NGS. However, FISH failed to identify three patients (30%) with very-high MET RNA expression, among which one received MET tyrosine kinase inhibitor treatment deriving clinical benefit. Our results indicate that quantitative mRNA-based techniques can improve the selection of patients for MET-targeted therapies.

Detection of somatic mutations in peritoneal lavages and plasma of endometrial cancer patients: A proof-of-concept study.

Endometrial cancer (EC) is the most common gynecologic malignancy in developed countries. Although most patients are diagnosed at early stages, 15-20% will relapse despite local treatment. Presently, there are no reliable markers to identify patients with worse outcomes who may benefit from adjuvant treatments, such as chemotherapy, and liquid biopsies may be of use in this setting. Peritoneal lavages are systematically performed during endometrial surgery but little data are available about their potential as liquid biopsies. We analyzed KRAS and PIK3CA mutations in paired surgical biopsies, blood and cytology-negative peritoneal lavages in a cohort of 50 EC patients. Surgical biopsies were submitted to next-generation sequencing (NGS) while circulating-free DNA (cfDNA) purified from plasma and peritoneal lavages was analyzed for KRAS and PIK3CA hotspot mutations using a sensitive quantitative polymerase chain reaction (PCR) assay. NGS of biopsies revealed KRAS, PIK3CA or concomitant KRAS + PIK3CA mutations in 33/50 (66%) EC patients. Of those, 19 cases carried hotspot mutations. Quantitative PCR revealed KRAS and/or PIK3CA mutations in the lavages of 9/19 (47.4%) hotspot EC patients. In contrast, only 2/19 (10.5%) blood samples from hotspot EC patients were positive. Mutations found in cfDNA consistently matched those in paired biopsies. One of the two patients positive in plasma and lavage died in less than 6 months. In conclusion, mutational analysis in peritoneal lavages and blood from early stage EC is feasible. Further studies are warranted to determine if it might help to identify patients with worse prognosis. Human genes discussed: KRAS, KRAS proto-oncogene, GTPase; PIK3CA, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha.

Prospective detection of mutations in cerebrospinal fluid, pleural effusion, and ascites of advanced cancer patients to guide treatment decisions.

Many advanced cases of cancer show central nervous system, pleural, or peritoneal involvement. In this study, we prospectively analyzed if cerebrospinal fluid (CSF), pleural effusion (PE), and/or ascites (ASC) can be used to detect driver mutations and guide treatment decisions. We collected 42 CSF, PE, and ASC samples from advanced non-small-cell lung cancer and melanoma patients. Cell-free DNA (cfDNA) was purified and driver mutations analyzed and quantified by PNA-Q-PCR or next-generation sequencing. All 42 fluid samples were evaluable; clinically relevant mutations were detected in 41 (97.6%). Twenty-three fluids had paired blood samples, 22 were mutation positive in fluid but only 14 in blood, and the abundance of the mutant alleles was significantly higher in fluids. Of the 34 fluids obtained at progression to different therapies, EGFR resistance mutations were detected in nine and ALK acquired mutations in two. The results of testing of CSF, PE, and ASC were used to guide treatment decisions, such as initiation of osimertinib treatment or selection of specific ALK tyrosine-kinase inhibitors. In conclusion, fluids close to metastatic sites are superior to blood for the detection of relevant mutations and can offer valuable clinical information, particularly in patients progressing to targeted therapies.

Prospective analysis of liquid biopsies of advanced non-small cell lung cancer patients after progression to targeted therapies using GeneReader NGS platform.

BACKGROUND: In a significant percentage of advanced non-small cell lung cancer (NSCLC) patients, tumor tissue is unavailable or insufficient for genetic analyses at time to progression. We prospectively analyzed the appearance of genetic alterations associated with resistance in liquid biopsies of advanced NSCLC patients progressing to targeted therapies using the NGS platform. METHODS: A total of 24 NSCLC patients were included in the study, 22 progressing to tyrosine kinase inhibitors and two to other treatments. Liquid biopsies samples were obtained and analyzed using the GeneReadTM QIAact Lung DNA UMI Panel, designed to enrich specific target regions and containing 550 variant positions in 19 selected genes frequently altered in lung cancer tumors. Previously, a retrospective validation of the panel was performed in clinical samples. RESULTS: Of the 21 patients progressing to tyrosine kinase inhibitors with valid results in liquid biopsy, NGS analysis identified a potential mechanism of resistance in 12 (57%). The most common were acquired mutations in ALK and EGFR, which appeared in 8/21 patients (38%), followed by amplifications in 5/21 patients (24%), and KRAS mutations in one patient (5%). Loss of the p.T790M was also identified in two patients progressing to osimertinib. Three of the 21 (14%) patients presented two or more concomitant alterations associated with resistance. Finally, an EGFR amplification was found in the only patient progressing to immunotherapy included in the study. CONCLUSIONS: NGS analysis in liquid biopsies of patients progressing to targeted therapies using the GeneReader platform is feasible and can help the oncologist to make treatment decisions.

Development of a gene panel for next-generation sequencing of clinically relevant mutations in cell-free DNA from cancer patients.

BACKGROUND: When tumour tissue is unavailable, cell-free DNA (cfDNA)can serve as a surrogate for genetic analyses. Because mutated alleles in cfDNA are usually below 1%, next-generation sequencing (NGS)must be narrowed to target only clinically relevant genes. In this proof-of-concept study, we developed a panel to use in ultra-deep sequencing to identify such mutations in cfDNA. METHODS: Our panel ('SiRe') covers 568 mutations in six genes (EGFR, KRAS, NRAS, BRAF, cKIT and PDGFRα)involved in non-small-cell lung cancer (NSCLC), gastrointestinal stromal tumour, colorectal carcinoma and melanoma. We evaluated the panel performance in three steps. First, we analysed its analytical sensitivity on cell line DNA and by using an artificial reference standard with multiple mutations in different genes. Second, we analysed cfDNA from cancer patients at presentation (n=42), treatment response (n=12) and tumour progression (n=11); all patients had paired tumour tissue and cfDNA previously genotyped with a Taqman-derived assay (TDA). Third, we tested blood samples prospectively collected from NSCLC patients (n=79) to assess the performance of SiRe in clinical practice. RESULTS: SiRe had a high analytical performance and a 0.01% lower limit of detection. In the retrospective series, SiRe detected 40 EGFR, 11 KRAS, 1 NRAS and 5 BRAF mutations (96.8% concordance with TDA). In the baseline samples, SiRe had 100% specificity and 79% sensitivity relative to tumour tissue. Finally, in the prospective series, SiRe detected 8.7% (4/46) of EGFR mutations at baseline and 42.9% (9/21) of EGFR p.T790M in patients at tumour progression. CONCLUSIONS: SiRe is a feasible NGS panel for cfDNA analysis in clinical practice.

Liquid Biopsy in Non-Small Cell Lung Cancer.

Liquid biopsy analyses are already incorporated in the routine clinical practice in many hospitals and oncology departments worldwide, improving the selection of treatments and monitoring of lung cancer patients. Although they have not yet reached its full potential, liquid biopsy-based tests will soon be as widespread as "standard" biopsies and imaging techniques, offering invaluable diagnostic, prognostic, and predictive information. This review summarizes the techniques available for the isolation and analysis of circulating free DNA and RNA, exosomes, tumor-educated platelets, and circulating tumor cells from the blood of cancer patients, presents the methodological challenges associated with each of these materials, and discusses the clinical applications of liquid biopsy testing in lung cancer.

Adaptive resistance to targeted therapies in cancer.

It is widely acknowledged that there is a need for molecular profiling in non-small-cell lung cancer. For example, treatment based on EGFR mutation status has attained successful results. However, in spite of excellent initial response to oral EGFR tyrosine kinase inhibitors (TKIs), progression-free survival is still limited. Current research has focused mostly on acquired resistance mechanisms, such as overexpression of AXL and loss of the Mediator MED12. In this review, in contrast, we discuss adaptive, rather than acquired, resistance. Adaptive resistance can occur almost immediately after starting targeted therapy through a rapid rewiring of cancer cell signaling. By losing ERK negative feedback on receptor tyrosine kinase (RTK) expression, cancer cells are exposed to the stimuli of several ligands, and the ensuing activation of several RTKs reprograms all the canonical signaling pathways. The overexpression of several RTKs was observed in breast cancer cell lines treated with a MEK inhibitor and in BRAF(V600E) melanoma cell lines treated with BRAF inhibitors. This rebound effect of overexpression of several RTKs, including ERBB3, also occurs in lung cancers driven by Kras or EGFR mutations when treated with MEK, PI3K or dual PI3K/mTOR inhibitors. Synthetic lethality can be effectively induced by co-targeting these overexpressed RTKs. We speculate that in patients with EGFR mutations, adaptive resistance occurs in a significant proportion of patients. Rebiopsies performed hours after starting treatment with EGFR TKIs can identify which RTKs are overexpressed after treatment. Efficient co-targeting of these RTKs can induce synthetic lethality and help overcome the limited effect of EGFR TKI monotherapy.