Quality of life with first-line pembrolizumab for PD-L1-positive advanced gastric/gastroesophageal junction adenocarcinoma: results from the randomised phase III KEYNOTE-062 study

BACKGROUND

In the randomised phase III KEYNOTE-062 study, pembrolizumab was non-inferior to chemotherapy for overall survival in patients with programmed death-ligand 1 (PD-L1)-positive [combined positive score (CPS) ≥1] advanced gastric/gastroesophageal junction (GEJ) cancer. We present findings of prespecified health-related quality-of-life (HRQOL) analyses for pembrolizumab versus chemotherapy in this population.

MATERIALS AND METHODS

HRQOL, a secondary endpoint, was measured in patients who received ≥1 dose of study treatment and completed ≥1 HRQOL questionnaire [European Organisation for the Research and Treatment of Cancer (EORTC) 30-question quality-of-life (QLQ-C30), EORTC 22-question quality-of-life gastric-cancer-specific module (QLQ-STO22)]. Least squares mean (LSM) change (baseline to week 18) in global health status/quality of life (GHS/QOL; EORTC QLQ-C30) and time to deterioration (TTD) in GHS/QOL, nausea/vomiting and appetite loss scores (EORTC QLQ-C30) and abdominal pain/discomfort scores (EORTC QLQ-STO22) were evaluated.

RESULTS

The HRQOL population comprised 495 patients with CPS ≥1 (pembrolizumab, 252; chemotherapy, 243). Compliance rates at week 18 were similar for pembrolizumab and chemotherapy (EORTC QLQ-C30, 87.9% and 81.9%; EORTC QLQ-STO22, 87.9% and 81.3%, respectively). There was no between-arm difference in LSM score change in GHS/QOL [-0.16; 95% confidence interval (CI) -5.01 to 4.69; P = 0.948]. The LSM score change for most subscales showed comparable worsening in both arms. TTD for GHS/QOL [hazard ratio (HR), 0.96; 95% CI, 0.67-1.38; P = 0.826], appetite loss (HR, 0.83; 95% CI, 0.58-1.20; P = 0.314) and pain (HR, 1.22; 95% CI, 0.78-1.91; P = 0.381) were similar between arms. Longer TTD was observed for pembrolizumab versus chemotherapy for nausea/vomiting (HR, 0.61; 95% CI, 0.44-0.85; P = 0.003).

CONCLUSIONS

HRQOL was maintained with first-line treatment with pembrolizumab in patients with PD-L1-positive advanced gastric/GEJ cancer and was similar between pembrolizumab and chemotherapy in this population.

Cloning and characterization of a general amino acid control transcriptional activator from the chestnut blight fungus Cryphonectria parasitica

We have cloned and characterized a homologue of the Neurospora crassa general amino acid control gene cpc-1 from the chestnut blight fungus Cryphonectria parasitica. The deduced amino acid sequence of C. parasitica CPC1 (cpCPC1) contains regions with significant homology to the transcriptional activation, DNA binding, and dimerization domains previously defined for N. crassa CPC1 (ncCPC1) and the equivalent "b-ZIP" transcription factor from Saccharomyces cerevisiae, GCN4 (scGCN4). Treatment of C. parasitica with low levels of the protein synthesis inhibitor cycloheximide caused cpc-1 transcript levels to undergo a rapid, transient increase similar to that reported for the mammalian b-ZIP transactivators, c-Jun and c-Fos. Northern analysis also revealed that amino acid starvation of C. parasitica elicits an increase in cpc-1 transcript levels. Hypovirus infection did not affect this increase, although transcript accumulation for several amino acid biosynthetic genes was slightly diminished in the hypovirus-containing strain. Recombinant cpCPC1 specifically bound to the consensus DNA binding element (AP-1), 5'-A/GTGACTCAT-3', also located upstream of the C. parasitica cpc-1 coding region. Constitutive transgenic expression of a DNA binding defective cpCPC1 mutant impaired the ability of C. parasitica to adjust to amino acid starvation. Moreover, these transformants showed reduced ability to grow on host chestnut tissue. Our results define a general amino acid control transactivator in a plant pathogenic fungus and suggest that functional modulation of this factor can influence fungal virulence.

Altered transcriptional response to nutrient availability in hypovirus-infected chestnut blight fungus

The gene lac-1, encoding the enzyme laccase, is one of several genes of the chestnut blight fungus, Cryphonectria parasitica, that are suppressed by virulence-attenuating mycoviruses of the hypovirus group. Two antagonistic regulatory pathways have been shown to govern the activity of the lac-1 promoter: a positive pathway that stimulates transcription and a negative pathway that represses transcription. We now report that these two regulatory pathways respond independently to specific changes in the nutritional environment. These newly defined conditions were used to confirm that a hypovirus suppresses the activity of the positive regulatory pathway, and to implicate calmodulin and calcineurin as components of the signal transduction cascades regulating lac-1 transcription. Significantly, lac-1 transcript accumulation was shown to be affected by amino acid availability. Further analysis revealed that transcriptional repression mediated by the negative regulatory pathway is relieved under conditions of amino acid deprivation. Thus, by blocking the positive pathway, hypovirus infection prevents increased lac-1 transcript accumulation in response to amino acid deficiency. These observations are consistent with the hypothesis that hypoviruses alter the transcriptional response of the host fungus to changes in nutrient availability.

Cyclophilin-dependent stimulation of transcription by cyclosporin A

Exposure to cyclosporin A (CspA) increased laccase (lac-1) transcript accumulation in the chestnut blight fungus Cryphonectria parasitica. This response was suppressed by compounds that interfere with calcium-dependent signal transduction and by the presence of a virulence-attenuating mycovirus. CspA stimulated the accumulation of mRNA from a nonhomologous reporter fused to the lac-1 promoter, indicating that the increased transcript levels resulted from an increase in promoter activity. Based on the current model for the regulation of lac-1 transcription, these results suggest that CspA interferes with a negative regulatory pathway that normally constrains lac-1 promoter activity. Significantly, CspA did not stimulate lac-1 transcription in mutant strains deficient in CspA binding activity, directly demonstrating a requirement for the interaction of CspA and cyclophilin in the modulation of lac-1 transcription. Our results establish that CspA treatment can stimulate gene transcription and that cyclophilin is the cellular receptor that mediates this activity.

Regulatory pathways governing modulation of fungal gene expression by a virulence-attenuating mycovirus

A viral double-stranded RNA associated with virulence attenuation (hypovirulence) in the chestnut blight fungus (Cryphonectria parasitica) has been shown by DNA-mediated transformation to be responsible for transmissible hypovirulence. In addition to reduced virulence, the fungal strain harboring this virus exhibits a diverse array of characteristics, termed hypovirulence-associated traits, which distinguish it from an isogenic virus-free strain. We have investigated one of these traits, suppressed lac-1 (laccase) transcript accumulation. Two different and opposing regulatory pathways appear to govern lac-1 transcript levels in the virus-free strain: a stimulatory pathway was found to be dependent on the inositol trisphosphate (IP3) and calcium second messenger systems. A second pathway limiting transcript accumulation was shown to require ongoing protein synthesis. Additionally, changes in the level of lac-1 transcript accumulation were found to be related to modulation of promoter activity and this activity was shown to be suppressed in the virus-containing strain. We conclude that this hypovirulence-associated virus interferes with transduction of an IP3-calcium-dependent signal that is required for stimulation of lac-1 transcription. The perturbation of such signal transduction pathways by hypovirulence-associated viruses may account for the manifold symptoms associated with transmissible hypovirulence.

Donor DNA processing is blocked by a mutation in the com101A locus of Haemophilus influenzae

Evidence is presented indicating that a donor DNA processing step of the Haemophilus influenzae transformation pathway is blocked in the Com-101 mutant. Additional data are presented suggesting that, as in the Rec-2 strain, the donor DNA remains associated with the H. influenzae envelope.

Sequence and transcriptional regulation of com101A, a locus required for genetic transformation in Haemophilus influenzae

A 2.8-kb EcoRI-BglII fragment cloned from the wild-type Haemophilus influenzae Rd chromosome is shown to increase the transformability of the Com-101 mutant through trans complementation. Deletion and sequence analyses indicate that the active region of the clone carries a 687-bp open reading frame. A 0.3-kb insertion in the corresponding EcoRI-BglII fragment of the Com-101 chromosome is shown to be a partial (331-bp) duplication of this open reading frame. The wild-type sequence produces a peptide of a size that is consistent with the sequence data when this sequence is expressed in Escherichia coli with a T7 promoter-based transcription vector. RNA hybridization analysis using a DNA probe derived from the open reading frame suggests that the sequence is transiently expressed during competence development. On the basis of these observations, it is proposed that the open reading frame corresponds to the com101A gene.

Molecular cloning of two linked loci that increase the transformability of transformation-deficient mutants of Haemophilus influenzae

A plasmid containing a 13.3-kb insert (pER194) was isolated from an EcoRI genomic library of Haemophilus influenzae on the basis of its ability to increase the transformability of the transformation-deficient mutants Com-78 and Com-101. The plasmid failed to increase the transformability of the Rec-1 and Rec-2 mutants, indicating that the mutations producing the Com-78 and Com-101 phenotypes are distinct from those giving rise to the Rec-1 and Rec-2 phenotypes. The physical mapping of the cloned fragment on the H. influenzae chromosome was found to be consistent with the genetic mapping of the Com-101 trait. A 2.8-kb EcoRI-BglII subfragment, representing one end of the 13.3-kb clone, was found to increase the transformation frequency of the Com-78 and Com-101 mutants when supplied in trans, indicating that the subfragment carries one or more loci required for chromosomal transformation. The corresponding region of the Com-101 chromosome was determined by hybridization analysis to contain a 0.3-kb insertion, suggesting that the Com-101 strain may contain an insertion mutation at this locus. A 3.0-kb EcoRI-MluI subfragment, representing the other end of the 13.3-kb EcoRI fragment, was found to increase the transformation frequency of the Com-101 mutant but not of the Com-78 mutant, suggesting that the Com-101 phenotype results from a complex genotype involving mutations at two or more transformation-related loci. This conclusion is consistent with data indicating that the Com-101 trait can be genetically separated into at least two components.