Impact of KRASG12 mutations on survival with trifluridine/tipiracil plus bevacizumab in patients with refractory metastatic colorectal cancer: post hoc analysis of the phase III SUNLIGHT trial.

BACKGROUND: In metastatic colorectal cancer (mCRC), KRAS mutations are often associated with poorer survival; however, the prognostic impact of specific point mutations is unclear. In the phase III SUNLIGHT trial, trifluridine/tipiracil (FTD/TPI) plus bevacizumab significantly improved overall survival (OS) versus FTD/TPI alone. We assessed the impact of KRASG12 mutational status on OS in SUNLIGHT. PATIENTS AND METHODS: In the global, open-label, randomized, phase III SUNLIGHT trial, adults with mCRC who had received no more than two prior chemotherapy regimens were randomized 1 : 1 to receive FTD/TPI alone or FTD/TPI plus bevacizumab. In this post hoc analysis, OS was assessed according to the presence or absence of a KRASG12 mutation in the overall population and in patients with RAS-mutated tumors. RESULTS: Overall, 450 patients were analyzed, including 302 patients in the RAS mutation subgroup (214 with a KRASG12 mutation and 88 with a non-KRASG12RAS mutation). In the overall population, similar OS outcomes were observed in patients with and without a KRASG12 mutation [median 8.3 and 9.2 months, respectively; hazard ratio (HR) 1.09, 95% confidence interval (CI) 0.87-1.4]. Similar OS outcomes were also observed in the subgroup analysis of patients with a KRASG12 mutation versus those with a non-KRASG12RAS mutation (HR 1.03, 95% CI 0.76-1.4). FTD/TPI plus bevacizumab improved OS compared with FTD/TPI alone irrespective of KRASG12 mutational status. Among patients with a KRASG12 mutation, the median OS was 9.4 months with FTD/TPI plus bevacizumab versus 7.2 months with FTD/TPI alone (HR 0.67, 95% CI 0.48-0.93), and in patients without a KRASG12 mutation, the median OS was 11.3 versus 7.1 months, respectively (HR 0.59, 95% CI 0.43-0.81). CONCLUSIONS: The presence of a KRASG12 mutation had no detrimental effect on OS among patients treated in SUNLIGHT. The benefit of FTD/TPI plus bevacizumab over FTD/TPI alone was confirmed independently of KRASG12 status.

Effect of KRAS codon 12 or 13 mutations on survival with trifluridine/tipiracil in pretreated metastatic colorectal cancer: a meta-analysis.

BACKGROUND: KRAS gene mutations can predict prognosis and treatment response in patients with metastatic colorectal cancer (mCRC). METHODS: We undertook a meta-analysis of three randomized, placebo-controlled trials (RECOURSE, TERRA and J003) to investigate the impact of KRAS mutations in codons 12 or 13 on overall survival (OS) and progression-free survival in patients receiving trifluridine/tipiracil (FTD/TPI) for refractory mCRC. RESULTS: A total of 1375 patients were included, of whom 478 had a KRAS codon 12 mutation and 130 had a KRAS codon 13 mutation. In univariate analyses, the absence of a KRAS codon 12 mutation was found to significantly increase the OS benefit of FTD/TPI relative to placebo compared with the presence of the mutation {hazard ratio (HR), 0.62 [95% confidence interval (CI): 0.53-0.72] versus 0.86 (0.70-1.05), respectively; interaction P = 0.0206}. Multivariate analyses showed that taking confounding factors into account reduced the difference in treatment effect between the presence and the absence of KRAS codon 12 mutations, confirming that treatment benefit was maintained in patients with [HR, 0.73 (95% CI: 0.59-0.89)] and without [HR, 0.63 (95% CI: 0.54-0.74)] codon 12 mutations (interaction P = 0.2939). KRAS mutations in codon 13 did not reduce the OS benefit of FTD/TPI relative to placebo, and, furthermore, KRAS mutations at either codon 12 or codon 13 did not affect the progression-free survival benefit. CONCLUSIONS: Treatment with FTD/TPI produced a survival benefit, relative to placebo, regardless of KRAS codon 12 or 13 mutation status in patients with previously treated mCRC.

First-line trifluridine/tipiracil + bevacizumab in patients with unresectable metastatic colorectal cancer: final survival analysis in the TASCO1 study.

BACKGROUND: Therapeutic options are limited in patients with unresectable metastatic colorectal cancer (mCRC) ineligible for intensive chemotherapy. The use of trifluridine/tipiracil plus bevacizumab (TT-B) in this setting was evaluated in the TASCO1 trial; here, we present the final overall survival (OS) results. METHODS: TASCO1 was an open-label, non-comparative phase II trial. Patients (n = 153) were randomised 1:1 to TT-B (trifluridine/tipiracil 35 mg/m2 orally twice daily on days 1-5 and 8-12, and bevacizumab intravenously 5 mg/kg on days 1 and 15 of each 28-day cycle) or capecitabine plus bevacizumab (C-B; capecitabine, 1250 mg/m2 orally twice daily on days 1-14 and bevacizumab 7.5 mg/kg intravenously on day 1 of each 21-day cycle). Final OS was analysed when all patients had either died or withdrawn from the study. Adjusted multivariate regression was used to investigate the effects of pre-specified variables on OS. RESULTS: At 1 September 2020, median OS was 22.3 months (95% CI: 18.0-23.7) with TT-B and 17.7 months (95% CI: 12.6-19.8) with C-B (adjusted HR 0.78; 95% CI: 0.55-1.10). No variables negatively affected OS with TT-B. Safety results were consistent with prior findings. CONCLUSIONS: TT-B is a promising therapeutic regimen in mCRC patients ineligible for intensive chemotherapy. CLINICAL TRIAL INFORMATION: NCT02743221 (clinicaltrials.gov).

Trifluridine/tipiracil in combination with oxaliplatin and either bevacizumab or nivolumab in metastatic colorectal cancer: a dose-expansion, phase I study.

BACKGROUND: In preclinical studies trifluridine/tipiracil (FTD/TPI) plus oxaliplatin (Industriestrasse, Holzkirchen, Germany) sensitised microsatellite stable (MSS) metastatic colorectal cancer (mCRC) to anti-programmed cell death protein-1; the addition of oxaliplatin or bevacizumab (F Hoffmann- la ROCHE AG, Kaiseraugst, Switzerland) enhanced the antitumour effects of FTD/TPI. This study aimed to investigate the safety and efficacy of FTD/TPI plus oxaliplatin and either bevacizumab or nivolumab (Uxbridge business Park, Uxbridge, United Kingdom) in patients with mCRC who had progressed after at least one prior line of treatment. PATIENTS AND METHODS: In 14-day cycles, patients received FTD/TPI 35 mg/m2 (twice daily, days 1-5) plus oxaliplatin 85 mg/m2 (day 1), and, on day 1, either bevacizumab 5 mg/kg (cohort A) or nivolumab 3 mg/kg (cohort B). Patients in Cohort B had confirmed MSS status. RESULTS: In total, 54 patients were enrolled: 37 in cohort A and 17 in cohort B. Recruitment in cohort B was stopped early due to the low response rate (RR) observed at interim analyses of efficacy. The most common adverse events (AEs) in cohort A were neutropenia/decreased neutrophils (75.7%), nausea (59.5%), vomiting (40.5%), diarrhoea (37.8%), peripheral sensory neuropathy (37.8%), fatigue (35.1%) and decreased appetite (35.1%). In cohort B, the most common AEs were neutropenia/decreased neutrophils (70.6%), diarrhoea (58.8%), nausea (47.1%), vomiting (47.1%), fatigue (47.1%), asthenia (41.2%), paraesthesia (41.2%), thrombocytopenia/decreased platelets (35.3%) and decreased appetite (35.3%). Confirmed objective RR was 17.1% in cohort A and 7.1% in cohort B; the corresponding values for median progression-free survival in the two cohorts were 6.3 and 6.0 months. CONCLUSION: FTD/TPI plus oxaliplatin and bevacizumab or nivolumab had an acceptable safety profile and demonstrated antitumour activity in previously treated patients with mCRC.

Trifluridine/tipiracil plus bevacizumab in patients with untreated metastatic colorectal cancer ineligible for intensive therapy: the randomized TASCO1 study.

BACKGROUND: We designed an open-label, noncomparative phase II study to assess the safety and efficacy of first-line treatment with trifluridine/tipiracil plus bevacizumab (TT-B) and capecitabine plus bevacizumab (C-B) in untreated patients with unresectable metastatic colorectal cancer (mCRC) who were not candidates for combination with cytotoxic chemotherapies. PATIENTS AND METHODS: From 29 April 2016 to 29 March 2017, 153 patients were randomly assigned (1:1) to either TT-B (N = 77) or C-B (N = 76). The primary end point was progression-free survival (PFS). The primary PFS analysis was performed after 100 events (radiological progression or death) were observed. Secondary end points included overall survival (OS), quality of life (QoL; QLQ-C30 and QLQ-CR29 questionnaires), and safety. RESULTS: Median (range) duration of treatment was 7.8 (6.0-9.7) months and 6.2 (4.1-9.1) months in the TT-B and C-B groups, respectively. Median (range) PFS was 9.2 (7.6-11.6) and 7.8 (5.5-10.1) months, respectively. Median (range) OS was 18 (15.2 to NA) and 16.2 (12.5 to NA) months, respectively. QoL questionnaires showed no relevant changes over time for either treatment. Therapies were well tolerated. Patients receiving TT-B had more grade ≥3 neutropenia (47% versus 5% with C-B). Patients receiving C-B had more grade ≥3 hand-foot syndrome (12% versus 0% with TT-B) and grade ≥3 diarrhea (8% versus 1% with TT-B), consistent with the known safety profiles of these agents. CONCLUSION: TT-B treatment showed promising clinical activity in untreated patients with unresectable mCRC ineligible for intensive therapy, with an acceptable safety profile and no clinically relevant changes in QoL. CLINICAL TRIAL INFORMATION: NCT02743221 (ClinicalTrials.gov).

Immune-related adverse events with immune checkpoint blockade: a comprehensive review.

Cancer immunotherapy is coming of age; it has prompted a paradigm shift in oncology, in which therapeutic agents are used to target immune cells rather than cancer cells. The first generation of new immunotherapies corresponds to antagonistic antibodies that block specific immune checkpoint molecules cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), programmed cell death protein (PD-1) and its ligand PD-L1. Targeting these checkpoints in patients living with cancer had led to long-lasting tumour responses. By unbalancing the immune system, these new immunotherapies also generate dysimmune toxicities, called immune-related adverse events (IRAEs) that mainly involve the gut, skin, endocrine glands, liver, and lung but can potentially affect any tissue. In view of their undisputed clinical efficacy, anti-CTLA-4 and anti-PD-1 antibodies are entering in the routine oncological practice, and the number of patients exposed to these drugs will increase dramatically in the near future. Although steroids can be used to treat these IRAEs, the associated immunosuppression may compromise the antitumour response. Oncologists must be ready to detect and manage these new types of adverse events. This review focuses on the mechanisms of IRAE generation, putative relationship between dysimmune toxicity and antitumour efficacy, as a basis for management guidelines.

A retrospective analysis of the outcome of patients with recurrent and/or metastatic squamous cell carcinoma of the head and neck refractory to a platinum-based chemotherapy.

AIMS: Recurrent and/or metastatic squamous cell carcinoma of the head and neck (SCCHN) develops in around 72,000 people in Europe every year. Treatment options are limited, mainly consisting of platinum-based palliative chemotherapy, with median overall survival times of only 6-8 months. No standard second-line treatment after progression on platinum-based chemotherapy is available. Few data have reported the efficacy of these treatments and the outcome of the patients. In an effort to generate such data, this retrospective study analysed clinical records from 151 patients with SCCHN refractory to platinum-based chemotherapy treated between 1990 and 2000 at seven different centres around Europe. MATERIALS AND METHODS: Most patients (45%) received only best supportive care (BSC), and had a median survival of 56 days. A total of 28.5% of the patients received second-line chemotherapies: 16.6% radiotherapy and 9.9% chemoradiotherapy. RESULTS: No objective response was observed with the various second-line chemotherapies. The overall median survival was 103 days (95% confidence interval [CI]: 77-126 days) for the whole cohort. The overall objective response rate (ORR) to second-line treatment in this population was calculated to be 2.6%. CONCLUSION: These results highlight the need for additional treatment options for this disease. Similar, if not superior, response rates have already been observed in initial clinical studies of novel, targeted anti-cancer agents.

Effects of Gypsophila saponins on bacterial growth kinetics and on selection of subterranean clover rhizosphere bacteria.

Plant secondary metabolites, such as saponins, have a considerable impact in agriculture because of their allelopathic effects. They also affect the growth of soil microorganisms, especially fungi. We investigated the influence of saponins on rhizosphere bacteria in vitro and in soil conditions. The effects of gypsophila saponins on the growth kinetics of rhizosphere bacteria were studied by monitoring the absorbance of the cultures in microtiter plates. Gypsophila saponins (1%) increased the lag phase of bacterial growth. The impact of gypsophila saponins on subterranean clover rhizosphere was also investigated in a pot experiment. The addition of gypsophila saponins did not modify clover biomass but significantly increased (twofold with 1% saponins) the weight of adhering soil. The number of culturable heterotrophic bacteria of the clover rhizosphere was not affected by the addition of gypsophila saponins. Nevertheless, the phenotypical characterization of the dominant Gram-negative strains of the clover rhizosphere, using the Biolog system, showed qualitative and quantitative differences induced by 1% saponins. With the addition of saponins, the populations of Chryseomonas spp. and Acinetobacter spp., the two dominant culturable genera of control clover, were no longer detectable or were significantly decreased, while that of Aquaspirillum dispar increased and Aquaspirillum spp. became the major genus. Aquaspirillum dispar and Aquaspirillum spp. were also the dominant rhizosphere bacteria of Gypsophila paniculata, which greatly accumulates these saponins in its roots. These results suggest that saponins may control rhizosphere bacteria in soil through rhizodeposition mechanisms.

Distribution and location of polycyclic aromatic hydrocarbons (PAHs) and PAH-degrading bacteria within polluted soil aggregates.

A study was conducted to determine the location and distribution of PAH and PAH-degrading bacteria in different aggregate size fractions of an industrially polluted soil. The estimation of PAH-degrading bacteria using an MPN microplate technique indicated that these bacteria are most numerous in the aggregate size fractions corresponding to fine silt (2-20 microm) and clay (<2 microm) compared to larger fractions or unfractionated soil. PAH concentrations were also highest in the aggregate size fraction corresponding to fine silt. Similar results were found in a spiked soil (incubated for 6 months) with similar carbonated minerals. Transmission electron microscopy observations showed that the autochtonous PAH-degrading bacteria were embedded in the aggregates where PAHs were abundant. In spite of this extensive co-localisation PAH degradation was limited during 6 months incubation. This indicates that factors other than spatial distribution and PAH degrading ability control degradation rates. The fine silt fraction of the industrial soil had an elevated C/N ratio (35) compared to the clay fraction (C/N: 16). Thus the fraction which assumably had the highest specific surface area contained less PAH but similar numbers of PAH-degraders. N thus seem to play an important role in the long term, but as PAH degradation was low in fine size fractions, other sources/factors were probably limiting (easily degradable C, P org, O2 etc.). Based on these findings, soil particle organization and structure of soil aggregates appear to be important for the characterization of a polluted soil (localization and sequestration). Manipulations that modify aggregation in polluted soils could thus potentially influence the accessibility and biodegradability of PAHs.

Colonization of wheat roots by an exopolysaccharide-producing pantoea agglomerans strain and its effect on rhizosphere soil aggregation

The effect of bacterial secretion of an exopolysaccharide (EPS) on rhizosphere soil physical properties was investigated by inoculating strain NAS206, which was isolated from the rhizosphere of wheat (Triticum durum L.) growing in a Moroccan vertisol and was identified as Pantoea aglomerans. Phenotypic identification of this strain with the Biotype-100 system was confirmed by amplified ribosomal DNA restriction analysis. After inoculation of wheat seedlings with strain NAS206, colonization increased at the rhizoplane and in root-adhering soil (RAS) but not in bulk soil. Colonization further increased under relatively dry conditions (20% soil water content; matric potential, -0.55 MPa). By means of genetic fingerprinting using enterobacterial repetitive intergenic consensus PCR, we were able to verify that colonies counted as strain NAS206 on agar plates descended from inoculated strain NAS206. The intense colonization of the wheat rhizosphere by these EPS-producing bacteria was associated with significant soil aggregation, as shown by increased ratios of RAS dry mass to root tissue (RT) dry mass (RAS/RT) and the improved water stability of adhering soil aggregates. The maximum effect of strain NAS206 on both the RAS/RT ratio and aggregate stability was measured at 24% average soil water content (matric potential, -0.20 MPa). Inoculated strain NAS206 improved RAS macroporosity (pore diameter, 10 to 30 &mgr;m) compared to the noninoculated control, particularly when the soil was nearly water saturated (matric potential, -0.05 MPa). Our results suggest that P. agglomerans NAS206 can play an important role in the regulation of the water content (excess or deficit) of the rhizosphere of wheat by improving soil aggregation.

High-level secretion of correctly processed recombinant human interleukin-1 beta in Kluyveromyces lactis.

The lactose-assimilating yeast, Kluyveromyces lactis, has been developed as a microbial host for the synthesis and secretion of human proteins. Here, we report the use of multi-copy vectors based on the 2 mu-like plasmid pKD1 from Kluyveromyces drosophilarum [Chen et al., Nucleic Acids Res. 14 (1986) 4471-4481] for the secretion of recombinant human interleukin-1 beta (reIL-1 beta). High levels of reIL-1 beta were secreted into the growth medium when the structural gene was fused in-frame to a synthetic secretion signal derived from the 'pre'-region of the K. lactis killer toxin. N-terminal sequencing of the excreted protein showed highly efficient (greater than 95%) maturation of the signal sequence. Synthesis as prepro-IL-1 beta, the 'pro'-sequence being derived from the human serum albumin-encoding gene, resulted in equally efficient secretion of mature IL-1 beta. Cytoplasmic production of Met-IL-1 beta, without a secretion signal, was found to be toxic to K. lactis. As in Saccharomyces cerevisiae [Baldari et al., EMBO J. 6 (1987) 229-234], but unlike native human IL-1 beta, K. lactis reIL-1 beta is glycosylated. This glycosylation led to a 95% loss of its biological activity. Removal of the carbohydrate chains by endo-beta-N-acetyl-glucosamidase H treatment fully restored the biological activity. A modified form of IL-1 beta (Asn7----Gln7), in which the unique site for Asn-linked glycosylation was deleted, exhibited the same biological activity as native IL-1 beta. The level of secretion of mature recombinant IL-1 beta ws glycosylation-independent.

Stable multicopy vectors for high-level secretion of recombinant human serum albumin by Kluyveromyces yeasts.

We have designed stable pKD1 derivatives for efficient secretion of recombinant human serum albumin (rHSA) by industrial strains of Kluyveromyces yeasts. A comparison of this multi-copy expression system with isogenic cassettes integrated at chromosomal loci demonstrated that high level secretion of rHSA is a function of gene dosage in K. lactis. Various signal sequences could be used, and the secretion levels were independent of the presence of the native pro peptide. The mitotic stability of the pKD1-based expression vectors was found to be species and strain dependent and was influenced by promoter strength and culture conditions. Vector stability was drastically enhanced when the HSA gene was expressed from an inducible promoter: 90% of the transformed cells still harbored the vector after 100 generations of non-selective growth in uninduced culture conditions. Secretion levels in the range of several grams per liter of correctly folded and processed rHSA were obtained at the pilot scale, thus making the industrial production of pharmaceutical-grade, Kluyveromyces-derived rHSA economically feasible.