First-line pembrolizumab plus chemotherapy for advanced/metastatic esophageal cancer: 1-year extended follow-up in the Japanese subgroup of the phase 3 KEYNOTE-590 study

BACKGROUND

First-line pembrolizumab plus chemotherapy (pembrolizumab-chemotherapy) demonstrated improved efficacy and a manageable safety profile versus placebo plus chemotherapy (placebo-chemotherapy) in the subgroup analysis of Japanese patients with advanced/metastatic esophageal cancer in KEYNOTE-590 at a median follow-up of 24.4 months. Longer-term data from the Japanese subgroup analysis of KEYNOTE-590 are reported.

METHODS

Patients were randomly assigned 1:1 to pembrolizumab 200 mg or placebo every 3 weeks for ≤ 35 cycles plus chemotherapy (cisplatin 80 mg/m2 and 5-fluorouracil 800 mg/m2/day). Endpoints included overall survival (OS) and progression-free survival (PFS; investigator-assessed per RECIST v1.1; dual primary) and safety (secondary). Early tumor shrinkage (ETS) and depth of response (DpR) were assessed post hoc.

RESULTS

Overall, 141 patients were enrolled in Japan. As of July 9, 2021, median follow-up was 36.6 months (range, 29.8-45.7). Pembrolizumab-chemotherapy showed a trend toward favorable OS (hazard ratio [HR], 0.70; 95% confidence interval [CI] 0.47-1.03) and PFS (0.57; 0.39-0.83) versus placebo-chemotherapy. In the pembrolizumab-chemotherapy group, patients with ETS ≥ 20% (55/74; 74.3%) versus < 20% (19/74; 25.7%) had favorable OS (HR, 0.23; 95% CI 0.12-0.42) and PFS (0.24; 0.13-0.43). Patients with DpR ≥ 60% (31/74; 41.9%) versus < 60% (43/74; 58.1%) had favorable OS (HR, 0.37; 95% CI 0.20-0.68) and PFS (0.24; 0.13-0.43). Grade 3-5 treatment-related adverse events occurred in 55/74 patients (74.3%) with pembrolizumab-chemotherapy and 41/67 patients (61.2%) with placebo-chemotherapy.

CONCLUSIONS

With longer-term follow-up of Japanese patients with advanced/metastatic esophageal cancer, efficacy continued to favor pembrolizumab-chemotherapy compared with placebo-chemotherapy, with no new safety signals observed.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT03189719.

Pharmacokinetics and immunogenicity of eftozanermin alfa in subjects with previously-treated solid tumors or hematologic malignancies: results from a phase 1 first-in-human study

PURPOSE

Eftozanermin alfa is a second-generation tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor agonist that enhances death receptor 4/5 clustering on tumor cells to induce apoptosis. We report the pharmacokinetics and immunogenicity of eftozanermin alfa administered intravenously to 153 adults with previously-treated solid tumors or hematologic malignancies from the first-in-human, open-label, dose-escalation and dose-optimization study.

METHODS

Dose escalation evaluated eftozanermin alfa monotherapy 2.5-15 mg/kg on Day 1 or Days 1/8 of a 21-day cycle. Dose optimization evaluated eftozanermin alfa monotherapy or combination therapy with either oral venetoclax 400-800 mg daily (eftozanermin alfa 1.25-7.5 mg/kg Days 1/8/15 of a 21-day cycle) or chemotherapy (eftozanermin alfa 3.75 or 7.5 mg/kg Days 1/8/15/22 of a 28-day cycle and FOLFIRI regimen [leucovorin, 5-fluorouracil, and irinotecan] with/without bevacizumab on Days 1/15 of a 28-day cycle).

RESULTS

Systemic exposures (maximum observed concentration [Cmax] and area under the concentration-time curve [AUC]) of eftozanermin alfa were approximately dose-proportional across the entire dose escalation range with minimal to no accumulation in Cycle 3 versus Cycle 1 exposures. Comparable exposures and harmonic mean half-lives (35.1 h [solid tumors], 31.3 h [hematologic malignancies]) were observed between malignancy types. Exposures (dose-normalized Cmax and AUC) in Japanese subjects were similar to non-Japanese subjects. Furthermore, eftozanermin alfa/venetoclax combination therapy did not have an impact on the exposures of either agent. Treatment-emergent anti-drug antibodies were observed in 9.4% (13/138) of subjects.

CONCLUSIONS

The study results, including a pharmacokinetic profile consistent with weekly dosing and low incidence of immunogenicity, support further investigation of eftozanermin alfa.

TRIAL REGISTRATION ID

NCT03082209.

PD-1 inhibition with retifanlimab and/or arginase inhibition with INCB001158 in Japanese patients with solid tumors: A phase I study

BACKGROUND

Retifanlimab is a humanized monoclonal antibody targeting programmed death protein-1, and INCB001158 is an oral arginase inhibitor. This phase Ib study investigated retifanlimab, INCB001158, and their combination in Japanese patients with advanced solid tumors.

METHODS

Patients received retifanlimab (500 mg every 4 weeks [Q4W] i.v.) or escalating doses of INCB001158 (75 or 100 mg twice daily [BID]) monotherapy in Part 1 and combination of retifanlimab (500 mg Q4W) and INCB001158 (100 mg BID) in Part 2. Primary endpoints were safety, tolerability, dose-limiting toxicities (DLTs), and determination of recommended phase II doses in Japanese patients.

RESULTS

Eighteen patients (retifanlimab or INCB001158 monotherapy and combination; n = 6 each) were enrolled at 2 sites in Japan. There were no DLTs, fatal adverse events (AEs), or discontinuations due to AEs. Rash (all grade 1) was the most common treatment-emergent AE with retifanlimab (n = 6). Treatment-related AEs were reported with retifanlimab (n = 4) or INCB001158 (n = 2) monotherapy and with combination (n = 4); an immune-related AE (thyroid disorder, grade 2) was reported with combination. Two responses were observed with retifanlimab monotherapy (1 complete, 1 partial) and 1 stable disease (SD), for an overall response rate of 33.3% (95% confidence interval [CI], 4.3-77.7) and disease control rate (DCR) of 50% (95% CI, 11.8-88.2). Three patients had SD with INCB001158 monotherapy (DCR 50%; 95% CI, 11.8-88.2). No responses or SD were observed with combination therapy.

CONCLUSION

Retifanlimab, INCB001158, and their combination had acceptable safety profiles. Promising retifanlimab antitumor activity warrants further investigation in Japanese patients.

KEYNOTE-434 part B: A phase 1 study evaluating the combination of epacadostat, pembrolizumab, and chemotherapy in Japanese patients with previously untreated advanced non-small-cell lung cancer

BACKGROUND

Pembrolizumab plus epacadostat (indoleamine 2,3-dioxygenase-1 inhibitor) was well tolerated in Japanese patients with advanced solid tumors in part A of the nonrandomized, open-label, phase 1 KEYNOTE-434 study (NCT02862457). We report results from part B, which evaluated epacadostat plus pembrolizumab and chemotherapy in Japanese patients with advanced non-small-cell lung cancer (NSCLC).

METHODS

Eligible patients aged ≥ 20 years had histologically or cytologically confirmed stage IIIB or IV NSCLC with no prior systemic therapy, and ECOG performance status of 0 or 1. Patients received epacadostat 100 mg orally twice-daily, pembrolizumab 200 mg intravenously every-3-weeks for ≤ 35 cycles, and 4 cycles of chemotherapy (cohort 1: cisplatin plus pemetrexed, non-squamous; cohort 2: carboplatin plus pemetrexed, non-squamous; cohort 3: carboplatin plus paclitaxel, squamous or non-squamous). Primary endpoint was incidence of dose-limiting toxicities (DLTs). Following unfavorable results from other studies, a protocol amendment removed epacadostat from the treatment combination.

RESULTS

Of 19 patients, 7 were enrolled in cohort 1, and 6 each in cohorts 2 and 3. Median follow-up was 13.7 (range, 4.2-27.8) months. Five of 17 (29%) DLT-evaluable patients experienced ≥ 1 DLT (cohort 1, n = 1; cohorts 2 and 3, n = 2 each); most commonly maculopapular rash (grade 3, n = 3) and increased alanine aminotransferase (grade 2, n = 1; grade 3, n = 2). All patients experienced treatment-related adverse events (AEs); 58% experienced grade 3 or 4 treatment-related AEs. Objective response rate was 47%.

CONCLUSION

The combination of epacadostat plus pembrolizumab and chemotherapy was found to be tolerable in Japanese patients with advanced NSCLC.

TRIAL REGISTRATION

ClinicalTrials.gov , NCT02862457.

Pimitespib for the treatment of advanced gastrointestinal stromal tumors and other tumors

Pimitespib (TAS-116) is the first heat shock protein 90 (HSP90) inhibitor approved in Japan, and it is indicated for the treatment of gastrointestinal stromal tumors (GIST) that have progressed after treatment with imatinib, sunitinib and regorafenib. This review describes the preclinical and clinical research with pimitespib, including its mechanism of action, pharmacokinetics, clinical antitumour activity and safety. In a phase III study, pimitespib significantly prolonged progression-free survival compared with placebo (median 2.8 vs 1.4 months; hazard ratio 0.51; 95% CI 0.30-0.87; p = 0.006). Common treatment-related adverse events were diarrhoea, decreased appetite, increase in serum creatinine, malaise, nausea and eye disorders. The efficacy and safety of pimitespib are being investigated in other tumour types and in combination with other anticancer therapies.

A first-in-human phase I study of TAS-117, an allosteric AKT inhibitor, in patients with advanced solid tumors

PURPOSE

TAS-117 is a highly potent and selective, oral, allosteric pan-AKT inhibitor under development for advanced/metastatic solid tumors. The safety, clinical pharmacology, pharmacogenomics and efficacy were investigated.

METHODS

This phase I, open-label, non-randomized, dose-escalating, first-in-human study enrolled patients with advanced/metastatic solid tumors and comprised three phases (dose escalation phase [DEP], regimen modification phase [RMP], and safety assessment phase [SAP]). The SAP dose and regimen were determined in the DEP and RMP. Once-daily and intermittent dosing (4 days on/3 days off, 21-day cycles) were investigated. The primary endpoints were dose-limiting toxicities (DLTs) in Cycle 1 of the DEP and RMP and incidences of adverse events (AEs) and adverse drug reactions (ADRs) in the SAP. Secondary endpoints included pharmacokinetics, pharmacodynamics, pharmacogenomics, and antitumor activity.

RESULTS

Of 66 enrolled patients, 65 received TAS-117 (DEP, n = 12; RMP, n = 10; SAP, n = 43). No DLTs were reported with 24-mg/day intermittent dosing, which was selected as a recommended dose in SAP. In the SAP, 98.5% of patients experienced both AEs and ADRs (grade ≥ 3, 67.7% and 60.0%, respectively). In the dose range tested (8 to 32 mg/day), TAS-117 pharmacokinetics were dose proportional, and pharmacodynamic analysis showed a reduction of phosphorylated PRAS40, a direct substrate of AKT. Four patients in the SAP had confirmed partial response.

CONCLUSION

Oral doses of TAS-117 once daily up to 16 mg/day and intermittent dosing of 24 mg/day were well tolerated. TAS-117 pharmacokinetics were dose proportional at the doses evaluated. Antitumor activity may occur through AKT inhibition.

TRIAL REGISTRATION

jRCT2080222728 (January 29, 2015).

Quantitative Analysis of the Concentration of Trifluridine in Tumor Hypoxic Regions Using a Novel Platform Combining Functional Endoscopy and Mass Spectrometry

Hypoxic regions in solid tumors are highly resistant to drugs and thus represents an obstacle in drug discovery. Currently, however, there are technical barriers in sampling human hypoxic tumors and examining drug delivery with high sensitivity and accuracy. Herein, we present a new platform combining functional endoscopy and highly sensitive liquid chromatography-mass spectrometry (LC-MS) to assess drug delivery to hypoxic regions. Because oxygen saturation endoscopic imaging (OXEI), a functional endoscopy, can evaluate lesions and hypoxia in real-time by simultaneously acquiring a pseudocolor map of oxygen saturation and conventional endoscopic images, this platform can be used to evaluate drug delivery with human samples from hypoxic regions. As the first clinical application of this platform, the relationship between hypoxic regions and the concentration of trifluridine (FTD) incorporated into DNA was evaluated in patients with advanced gastric cancer treated with FTD/tipiracil (FTD/TPI; n = 13) by obtaining and analysis of tissue samples by OXEI and LC-MS and vascular maturity index by CD31/α-SMA staining ex vivo. The results showed that the concentration of FTD was significantly higher in the normoxic region than in the hypoxic region (P < 0.05) and there were significantly more immature vessels in hypoxic regions than in normoxic regions (P < 0.05). These results indicate that the platform was sufficiently sensitive to evaluate differences in drug anabolism in different oxygenic regions of human tumor tissue. This new platform allows quantitative drug analysis in hypoxic regions and is expected to initiate a new era of drug discovery and development.

Combined Social Frailty and Life-Space Activities Associated with Risk of Disability: A Prospective Cohort Study

OBJECTIVES

To examine the association between social frailty and life-space activities, and determine whether a combined status of life-space activities and social frailty is associated with risk of disability among older adults.

DESIGN

A prospective cohort study.

SETTING AND PARTICIPANTS

The participants were 8,301 older adults (mean age 72.9 ± 5.6 years, women [53.3%]) from a community setting.

METHODS

Life-space activities were evaluated using the Active Mobility Index (AMI) to assess activities in each life-space (distance from the respondent's home: up to 1 km, 1-10 km, or greater than 10 km) during the past 1 month. Activities were also assessed according to physical or social activity. Social frailty and characteristics were measured at the baseline. Incident disability was assessed according to long term care insurance.

RESULTS

The lowest scoring group was based on the quartile in each of the AMI scores (Q1), with reference to the highest scoring group, which had a higher odds ratios for social frailty (AMI total score Q1: OR 4.32, 95% CI 3.43-5.45, AMI physical score Q1: 2.19, 95% CI 1.79-2.69, AMI social score Q1: 5.04, 95% CI 3.94-6.44). During the follow-up (mean 23.5 months), 330 participants had incident disability. Incident disability was associated with social frailty. Combined status of social frailty and low AMI increased the risk of disability (HR 2.15, 95% CI 1.52-3.03), with reference to non-frailty and higher AMI scores.

CONCLUSIONS AND IMPLICATIONS

Social frailty or reduced activity in life-space assessment were identified as risk factors for incident disability. To decrease the risk of disability, the development of an intervention program to enhance activities and cope with social frailty is required.

p70S6K/Akt dual inhibitor DIACC3010 is efficacious in preclinical models of gastric cancer alone and in combination with trastuzumab

The PI3K-Akt-mTOR (PAM) pathway is implicated in tumor progression in many tumor types, including metastatic gastric cancer (GC). The initial promise of PAM inhibitors has been unrealized in the clinic, presumably due, in part, to the up-regulation of Akt signaling that occurs when the pathway is inhibited. Here we present that DIACC3010 (formerly M2698), an inhibitor of two nodes in the PAM pathway, p70S6K and Akt 1/3, blocks the pathway in in vitro and in vivo preclinical models of GC while providing a mechanism that inhibits signaling from subsequent Akt up-regulation. Utilizing GC cell lines and xenograft models, we identified potential markers of DIACC3010-sensitivity in Her2-negative tumors, i.e., PIK3CA mutations, low basal pERK, and a group of differentially expressed genes (DEGs). The combination of DIACC3010 and trastuzumab was evaluated in Her2-positive cell lines and models. Potential biomarkers for the synergistic efficacy of the combination of DIACC3010 + trastuzumab also included DEGs as well as a lack of up-regulation of pERK. Of 27 GC patient-derived xenograft (PDX) models tested in BALB/c nu/nu mice, 59% were sensitive to DIACC3010 + trastuzumab. Of the 21 HER2-negative PDX models, DIACC3010 significantly inhibited the growth of 38%. Altogether, these results provide a path forward to validate the potential biomarkers of DIACC3010 sensitivity in GC and support clinical evaluation of DIACC3010 monotherapy and combination with trastuzumab in patients with HER2- negative and positive advanced GCs, respectively.

Erdafitinib in patients with advanced solid tumours with FGFR alterations (RAGNAR): an international, single-arm, phase 2 study

BACKGROUND

FGFR alterations are reported across various malignancies and might act as oncogenic drivers in multiple histologies. Erdafitinib is an oral, selective pan-FGFR tyrosine kinase inhibitor with activity in FGFR-altered advanced urothelial carcinoma. We aimed to evaluate the safety and activity of erdafitinib in previously treated patients with FGFR-altered advanced solid tumours.

METHODS

The single-arm, phase 2 RAGNAR study was conducted at 156 investigative centres (hospitals or oncology practices that are qualified oncology study centres) across 15 countries. The study consisted of four cohorts based on tumour histology and patient age; the results reported in this Article are for the primary cohort of the study, defined as the Broad Panel Cohort, which was histology-agnostic. We recruited patients aged 12 years or older with advanced or metastatic tumours of any histology (except urothelial cancer) with predefined FGFR1-4 alterations (mutations or fusions according to local or central testing). Eligible patients had disease progression on at least one previous line of systemic therapy and no alternative standard therapy available to them, and an Eastern Cooperative Oncology Group performance status of 0-1 (or equivalent for adolescents aged 12-17 years). Patients received once-daily oral erdafitinib (8 mg/day with provision for pharmacodynamically guided up-titration to 9 mg/day) on a continuous 21-day cycle until disease progression or intolerable toxicity. The primary endpoint was objective response rate by independent review committee according to Response Evaluation Criteria In Solid Tumors (RECIST), version 1.1, or Response Assessment In Neuro-Oncology (RANO). The primary analysis was conducted on the treated population of the Broad Panel Cohort. This ongoing study is registered with ClinicalTrials.gov, number NCT04083976.

FINDINGS

Patients were recruited between Dec 5, 2019, and Feb 15, 2022. Of 217 patients treated with erdafitinib, 97 (45%) patients were female and 120 (55%) were male. The data cutoff was Aug 15, 2022. At a median follow-up of 17·9 months (IQR 13·6-23·9), an objective response was observed in 64 (30% [95% CI 24-36]) of 217 patients across 16 distinct tumour types. The most common grade 3 or higher treatment-emergent adverse events related to erdafitinib were stomatitis (25 [12%]), palmar-plantar erythrodysaesthesia syndrome (12 [6%]), and hyperphosphataemia (11 [5%]). The most commonly occurring serious treatment-related adverse events (grade 3 or higher) were stomatitis in four (2%) patients and diarrhoea in two (1%). There were no treatment-related deaths.

INTERPRETATION

RAGNAR results show clinical benefit for erdafitinib in the tumour-agnostic setting in patients with advanced solid tumours with susceptible FGFR alterations who have exhausted other treatment options. These results support the continued development of FGFR inhibitors in patients with advanced solid tumours.

FUNDING

Janssen Research & Development.

Body weight loss as a prognostic and predictive factor in previously treated patients with metastatic gastric cancer: post hoc analyses of the randomized phase III TAGS trial

BACKGROUND

Body weight loss (BWL) is a negative prognostic factor in metastatic gastric or gastroesophageal junction cancer (mGC/GEJC). In the phase III TAGS study, trifluridine/tipiracil improved survival versus placebo in third- or later-line mGC/GEJC. These retrospective analyses examined the association of early BWL with survival outcomes in TAGS.

METHODS

Efficacy and safety were assessed in patients who experienced < 3% or ≥ 3% BWL from treatment start until day 1 of cycle 2 (early BWL). The effect of early BWL on overall survival (OS) was assessed by univariate and multivariate analyses.

RESULTS

Body weight data were available for 451 of 507 (89%) patients in TAGS. In the trifluridine/tipiracil and placebo arms, respectively, 74% (224/304) and 65% (95/147) experienced < 3% BWL, whereas 26% (80/304) and 35% (52/147) experienced ≥ 3% BWL at cycle 1 end. Median OS was longer in < 3% BWL versus ≥ 3% BWL subgroups (6.5 vs 4.9 months for trifluridine/tipiracil; 6.0 vs 2.5 months for placebo). In univariate analyses, an unadjusted HR of 0.58 (95% CI, 0.46-0.73) for the < 3% vs ≥ 3% BWL subgroup indicated a strong prognostic effect of early BWL. Multivariate analyses confirmed early BWL as both prognostic (P < 0.0001) and predictive (interaction P = 0.0003) for OS. Similar results were obtained for progression-free survival. Any-cause grade ≥ 3 adverse events were reported in 77% and 82% of trifluridine/tipiracil-treated and 45% and 67% of placebo-treated patients with < 3% and ≥ 3% BWL, respectively.

CONCLUSIONS

In TAGS, early BWL was a strong negative prognostic factor for OS in patients with mGC/GEJC receiving third- or later-line treatment.

First-in-human study of E7130 (a tumor microenvironment-ameliorating microtubule inhibitor) in patients with advanced solid tumors: Primary results of the dose-escalation part

BACKGROUND

E7130 is a novel anticancer agent created from a total synthetic study of norhalichondrin B. The authors report the E7130 dose-escalation part of a first-in-human study of patients with advanced solid tumors (NCT03444701).

METHODS

Japanese patients ≥20 years of age were enrolled. E7130 was administered intravenously in two cycles: day 1 of a 21-day cycle (Q3W) or days 1 and 15 of a 28-day cycle (Q2W). Doses were escalated from 270 to 550 μg/m² for the Q3W group or 25-400 μg/m² for the Q2W group. The primary end point of the dose-escalation phase was safety and tolerability as assessed by the incidence of dose-limiting toxicities (DLTs) and adverse events. Other end points included determination of the maximum tolerated dose (MTD), pharmacokinetics, and pharmacodynamics.

RESULTS

Forty-four patients were enrolled: 15 in the E7130 Q3W group and 29 in the Q2W group. Treatment-emergent adverse events (TEAEs) occurred in all patients; the most common TEAE overall was leukopenia (78.6%). Grade 3-4 TEAEs occurred in 93.3% of patients in the Q3W group and 86.2% of patients in the Q2W group. None had a TEAE resulting in study drug discontinuation, and no treatment-related deaths were reported. Per the DLT evaluation, the MTDs were determined as 480 μg/m² Q3W and 300 μg/m² Q2W. Significant changes in multiple plasma biomarkers, including vascular endothelial growth factor 3 and matrix metallopeptidase 9, were dose-dependent after initial doses of 350-480 μg/m² .

CONCLUSIONS

E7130 480 μg/m² Q3W was chosen for the dose-expansion part over 300 μg/m² Q2W primarily per dose-dependent biomarker results.

Current status of and future prospects for the treatment of unresectable or metastatic gastrointestinal stromal tumours

Gastrointestinal stromal tumours (GISTs) are soft-tissue sarcomas of the gastrointestinal tract. Surgery is the standard treatment for localised disease, but the risk of relapse and progression to more advanced disease is substantial. Following the discovery of the molecular mechanisms underlying GISTs, targeted therapies for advanced GIST were developed, with the first being the tyrosine kinase inhibitor (TKI) imatinib. Imatinib is recommended in international guidelines as first-line therapy to reduce the risk of GIST relapse in high-risk patients, and for locally advanced, inoperable and metastatic disease. Unfortunately, imatinib resistance frequently occurs and, therefore, second-line (sunitinib) and third-line (regorafenib) TKIs have been developed. Treatment options are limited for patients with GIST that has progressed despite these therapies. A number of other TKIs for advanced/metastatic GIST have been approved in some countries. Ripretinib is approved as fourth-line treatment of GIST and avapritinib is approved for GIST harbouring specific genetic mutations, while larotrectinib and entrectinib are approved for solid tumours (including GIST) with specific genetic mutations. In Japan, pimitespib, a heat shock protein 90 (HSP90) inhibitor, is now available as a fourth-line therapy for GIST. Clinical studies of pimitespib have indicated that it has good efficacy and tolerability, importantly not displaying the ocular toxicity of previously developed HSP90 inhibitors. Additional approaches for advanced GIST have been investigated, including alternative uses of currently available TKIs (such as combination therapy), novel TKIs, antibody-drug conjugates, and immunotherapies. Given the poor prognosis of advanced GIST, the development of new therapies remains an important goal.

Quantitative analysis of drug distribution in heterogeneous tissues using dual-stacking capillary electrophoresis-mass spectrometry

BACKGROUND AND PURPOSE

Intratumour heterogeneity frequently leads to drug resistance, which is a major issue in drug discovery. Drug distribution is one of the key factors for elucidating the resistance mechanism; however, quantitative and regional drug measurement is challenging. Here, we developed a novel ultra-sensitive analytical method and applied it to HER3-targeting antibody-drug conjugate patritumab deruxtecan (HER3-DXd), aiming to explore its payload (DXd) distribution within heterogeneous tissues.

EXPERIMENTAL APPROACH

The developed analytical method is named LDMS-CE-MS, a capillary electrophoresis-mass spectrometry (CE-MS) coupled with a novel sample preconcentration/separation method called "large-volume dual-sample stacking by micelle collapse and sweeping (LDMS)". First, the analytical performance of LDMS-CE-MS for DXd detection was evaluated. Subsequently, we evaluated the bystander effect of HER3-DXd, where tumour tissues were excised from xenograft models and clinical specimens after administration of HER3-DXd. HER3-high expression, adjacent, and HER3-low expression regions were then sampled by laser microdissection to quantify the released DXd.

KEY RESULTS

LDMS concentrated DXd by 1000-fold and separated it from the hydrophilic bio-matrix through continuous capture and release by the charged micelles, allowing quantification at sub-attomole-level. DXd concentrations decreased in the order of antigen-high expression > adjacent > antigen-low expression regions in the tumour xenograft model, whereas in clinical specimens, adjacent and antigen-high expression regions had approximately the same concentration. These distributions represent a bystander effect.

CONCLUSIONS AND IMPLICATIONS

Our LDMS-CE-MS successfully visualized the attomole-level drug distributions in heterogeneous clinical specimens. This new platform opens a new era of quantitative pharmacokinetic analysis, facilitating drug discovery and development.

Trials in progress: TAM kinase inhibitor PF-07265807 and sasanlimab plus axitinib in patients with advanced or metastatic renal cell carcinoma—A phase 1, open-label, pharmacokinetic, safety and tolerability study

TPS743

Background: Tumor-associated macrophage kinases (TAMK) are expressed on tumor cells during malignant transformation. Inhibition of AXL and MERTK, members of the TAMK family, may lower the immune activation threshold and promote antitumor immunity. PF-07265807 (ARRY-067) is a small-molecule inhibitor of MERTK and AXL showing antitumor activity in preclinical models as monotherapy or combined with anti-programmed cell death protein 1 (anti-PD-1) antibodies (ab). Sasanlimab is an anti-PD-1 ab with acceptable safety profile being tested (300 mg SC Q4W, Phase 3) in non-muscle invasive bladder cancer. Axitinib is a VEGF inhibitor approved (single agent and combined with anti-PD-1 inhibitors) for advanced renal cell carcinoma (RCC). This first-in-human Phase 1, open-label, multi-center study (NCT04458259) will evaluate the safety, tolerability, pharmacokinetics, and preliminary antitumor activity of PF-07265807 in patients (pts) with advanced or metastatic solid tumors as a single agent and in combination with sasanlimab with or without axitinib. We describe here the dose escalation (Part 3) and dose expansion (Part 4) for the triplet combination of PF-07265807 + sasanlimab + axitinib. Methods: Eligible participants for the triplet cohorts are adult pts with confirmed unresectable advanced or metastatic clear cell RCC, with estimated creatinine clearance ≥30 mL/min and urinary protein <2+ or ≥2+ but 24-h urine protein:creatinine ratio <2 g/24 h. Pts for Part 4 need to have intermediate and poor risk RCC and no prior systemic therapy for metastatic disease. Other key eligibility criteria: measurable disease by RECIST 1.1 or non-measurable disease, ECOG PS 0–2, adequate bone marrow and liver function, and resolved acute effects of prior therapy. Each cycle is 21 days. Part 3 will determine the maximum tolerated dose/recommended phase 2 dose (MTD/RP2D) of PF-07265807 in triplet therapy using a Bayesian logistic regression model and the escalation with overdose control principle. After the MTD/RP2D is identified, Part 4 will further evaluate the safety and preliminary efficacy of PF-07265807 combined with sasanlimab and axitinib. Treatment with study drug will continue until disease progression, consent withdrawal, or unacceptable toxicity, whichever occurs first. Primary endpoints of Part 3 are incidence of dose-limiting toxicities, adverse events (AE), and laboratory (lab) abnormalities. For Part 4, the primary endpoints are objective response rate and complete response rate; secondary endpoints include disease control rate; time-to-event endpoints; AEs; lab abnormalities; concentrations of PF-07265807 and its metabolite, sasanlimab, and axitinib; and incidence and titer of anti-sasanlimab anti-drug antibodies response. The study started in late 2020 and is recruiting. Clinical trial information: NCT04458259 .

Efficacy and safety of erdafitinib in adults with cholangiocarcinoma (CCA) with prespecified fibroblast growth factor receptor alterations (FGFRalt) in the phase 2 open-label, single-arm RAGNAR trial: Expansion cohort results

610

Background: Erdafitinib (erda) is an oral selective pan-FGFR tyrosine kinase inhibitor approved to treat locally advanced or metastatic urothelial carcinoma in adults with susceptible FGFR3/2alt who have progressed during or after ≥1 line of platinum-containing chemotherapy . Interim results from the ongoing phase 2 RAGNAR study (NCT04083976) demonstrated tumor agnostic efficacy and safety of erda in adults with advanced solid tumors harboring prespecified FGFRalt after failure of standard therapies (Loriot Y, et al. J Clin Oncol 2022;40(suppl 16):3007). Here we report results from an expansion cohort of the RAGNAR study that enrolled only patients (pts) with CCA. Methods: Adults (aged ≥18 y) with advanced or metastatic CCA with predefined FGFR1-4alt (mutations/fusions [excluding amplifications] based on local/central test) and documented disease progression on ≥1 prior line of systemic therapy received oral erda until disease progression or intolerable toxicity. The primary end point is objective response rate (ORR) by independent review committee (IRC). Secondary end points include duration of response (DOR), disease control rate (DCR), clinical benefit rate (CBR), progression-free survival (PFS), overall survival (OS), investigator-assessed efficacy end points, and safety. Results: At data cutoff (median follow-up 20.4 mo), 35 pts with CCA received erda (median age 57 y [range 40-74], median 2 prior systemic therapy [range 1-6]); 90.9% had visceral metastasis, and 17.1% responded to last line of therapy. ORR by IRC was 60.0% (95% CI 42.1-76.1). Median time to onset of response was 1.5 mo (range 1.1-8.2). Responses were observed in pts harboring FGFR mutations and fusions and in pts with co-occurring genomic alterations. Median DCR and CBR were 100.0% (95% CI 90.0-100.0) and 71.4% (95% CI 53.7-85.4), respectively. Median DOR, PFS, and OS were 5.6 mo (95% CI 2.8-8.3), 8.4 mo (95% CI 5.5-9.7), and 18.7 mo (95% CI 8.9-not evaluable), respectively. Investigator-assessed efficacy end points were aligned with IRC results. The most common treatment-emergent adverse events (TEAEs) were hyperphosphatemia (82.9%), diarrhea (80.0%), and stomatitis (74.3%). The majority of pts (80.0%) had grade ≥3 TEAEs, the most common being anemia (22.9%), stomatitis (20.0%), and acute kidney injury (11.4%); 42.9% had serious TEAEs; 11.4% discontinued treatment due to TEAEs. No treatment-related deaths were observed. Conclusions: Data from the CCA expansion cohort of the phase 2 RAGNAR study demonstrate robust efficacy of erda in heavily pretreated adults with CCA harboring prespecified FGFR fusions or mutations, irrespective of co-occurring genomic alterations. Safety data were consistent with the known safety profile of erda. Clinical trial information: NCT04083976 .

KEYMAKER-U06 substudy 06A trial in progress: A phase 1/2 study of investigational agents with pembrolizumab (pembro) plus chemotherapy (chemo) or lenvatinib in PD-1/L1 treatment-naïve advanced esophageal cancer

TPS487

Background: Immunotherapy has improved clinical outcomes in esophageal carcinoma; however, patients with advanced esophageal cancer that progresses after first-line chemo continue to have limited treatment options and poor prognosis. KEYMAKER-U06 substudy 06A (NCT05342636) is evaluating pembro (anti–PD-1) + investigator choice of chemo (irinotecan or paclitaxel), MK-4280A, a coformulation of pembro and favezelimab (anti-LAG3) + chemo, pembro + MK-4830 (anti-ILT4) + chemo, and pembro + MK-4830 + lenvatinib (multitargeted RTK inhibitor) for the second-line treatment of patients with PD-1/L1 treatment-naive advanced esophageal squamous cell carcinoma (ESCC). Methods: KEYMAKER-U06 substudy 06A is a phase 1/2, multicenter, open-label study comprising a safety lead-in phase and an efficacy phase. Adults with histologically or cytologically confirmed metastatic or locally advanced ESCC, who experienced disease progression on 1 prior line of therapy, have not received anti-PD-1/L1 therapy, any immune-modulating therapy, and/or VEGF targeted therapy, have measurable disease per RECIST v1.1 confirmed by blinded independent central review (BICR), and have an Eastern Cooperative Oncology Group performance status of 0 or 1 are eligible. Patients are being allocated to 1 of 4 treatment arms: pembro 200 mg IV Q3W + investigator choice of chemo (paclitaxel 80-100 mg/m2 IV days 1, 8, and 15 of every 28-day cycle or irinotecan 180 mg/m2 day 1 of every 14-day cycle) (arm 1), MK-4280A (pembro 200 mg/favezelimab 800 mg IV day 1 then Q3W) + investigator choice of chemo (arm 2), pembro 200 mg IV Q3W + MK-4830 800 mg IV Q3W + investigator choice of chemo (arm 3), or pembro 200 mg IV Q3W + MK-4830 800 mg IV Q3W + lenvatinib 20 mg orally once daily (arm 4). Arms 2-4 will have a safety lead-in phase; arm 1 will not have a safety lead-in phase because the safety and tolerability of pembro + chemo has been established in multiple phase 3 studies in the first-line treatment setting. The safety lead-in phase includes 10 patients who will be closely monitored for dose-limiting toxicities (DLTs) for 21 days after the first dose of study intervention. If ≥4 patients experience DLTs in any treatment arm, then enrollment in the efficacy phase may be delayed to allow for examination of safety data and to consider design changes. If ≤3 patients experience DLTs, up to 30 patients per arm will be enrolled (inclusive of the 10 patients from the safety lead-in) for efficacy assessment. In the safety lead-in phase, the primary end point is safety/tolerability assessed by DLTs, adverse events (AEs), and discontinuation of treatment due to AEs. In the efficacy phase, the primary end point is ORR per RECIST v1.1 by BICR, and secondary end points are PFS and DOR, per RECIST v1.1 by BICR, and OS and safety/tolerability. Enrollment in this study is ongoing. Clinical trial information: NCT05342636 .

Trials in progress: A phase 1, open-label, pharmacokinetic, safety and tolerability study of PF-07265807 (selective TAM kinase inhibitor) alone or with sasanlimab in patients with advanced or metastatic solid tumors

TPS270

Background: Inhibition of Mer Proto-oncogene tyrosine kinase (MERTK) and AXL may lower the threshold for immune activation thereby promoting anti-tumor activity. PF-07265807 (ARRY-067) is a selective small-molecule inhibitor of the tumor-associated macrophage kinases MERTK and AXL. In preclinical models, PF-07265807 plus anti-programmed cell death protein 1 (anti-PD-1) antibodies show antitumor activity that results in long-term cures and resistance to tumor re-challenge. Sasanlimab is a monoclonal antibody to PD-1 administered subcutaneously (300 mg every 4 wk or equivalent); it has an acceptable safety profile and is being tested in a Phase 3 trial in non-muscle invasive bladder cancer. This first-in-human study will evaluate safety, tolerability, pharmacokinetics and preliminary anti-tumor activity of PF-07265807 alone and with sasanlimab in patients (pts) with selected advanced or metastatic solid tumors. Study design of PF-07265807 monotherapy dose escalation (Part 1) was presented at ASCO 2021 (TPS2671). Here, we describe dose escalation (Part 2) and dose expansion (Part 4) cohorts for the doublet combination of PF-07265807 + sasanlimab. Methods: This is a Phase 1, open-label, multi-center study (NCT04458259) of PF-07265807. Adult pts with selected advanced or metastatic solid tumors who are intolerant or resistant to standard therapy will enroll into doublet therapy dose escalation (Part 2). Pts who are anti-PD-1/PD-L1 treatment naïve with intermediate tumor mutational burden (defined as ≥6 and < 16 microsatellite stable) colorectal cancer (CRC) or PD-L1+ (defined as combined positive score ≥1) gastric cancer will enroll into doublet therapy dose expansion cohorts (Part 4). Other key eligibility criteria: measurable or non-measurable disease by RECIST 1.1; ECOG PS 0–2; adequate bone marrow, renal and liver function; and resolved acute effects of any prior therapy. Each cycle will be 21 days. Treatment will continue until disease progression or unacceptable toxicity, whichever occurs first. The doublet maximum tolerated dose (MTD) will be guided by a Bayesian analysis of dose limiting toxicity (DLT) data for doublet therapy (Part 2). The recommended phase 2 dose (RP2D) will then be determined via holistic data review with/without the MTD identification. Primary endpoints in Part 2 include the incidence of DLTs, adverse events and laboratory abnormalities. After doublet MTD/RP2D is identified in Part 2, the preliminary anti-tumor activity of PF-07265807 + sasanlimab will be explored in Part 4. Primary endpoints in Part 4 include objective response and complete response rates; secondary endpoints include disease control rate and response duration, adverse events and laboratory abnormalities. The study began in Q4 2020 and is recruiting pts. Clinical trial information: NCT04458259 .

Comprehensive clinical and molecular characterization of claudin 18.2 expression in advanced gastric or gastroesophageal junction cancer

BACKGROUND

We conducted comprehensive clinical and molecular characterization of claudin 18.2 expression (CLDN18.2) in advanced gastric or gastroesophageal junction cancer (GC/GEJC).

PATIENTS AND METHODS

Patients with advanced GC/GEJC who received systemic chemotherapy from October 2015 to December 2019 with available tumor specimens were analyzed. We evaluated clinicopathological features of CLDN18.2 expression with four molecular subtypes: mismatch repair deficient, Epstein-Barr virus-positive, human epidermal growth factor receptor 2-positive, and others. In addition, programmed death-ligand 1 (PD-L1) combined positive score (CPS), genomic alterations, and the expression of immune cell markers were assessed. Clinical outcomes of standard first- or second-line chemotherapy and subsequent anti-programmed cell death protein 1 (anti-PD-1) therapy were also investigated according to CLDN18.2 expression.

RESULTS

Among 408 patients, CLDN18.2-positive (moderate-to-strong expression in ≥75%) was identified in 98 patients (24.0%) with almost equal distribution in the four molecular subtypes or CPS subgroups. CLDN18.2-positive was associated with Borrmann type 4, KRAS amplification, low CD16, and high CD68 expression. Overall survival with first-line chemotherapy was not significantly different between CLDN18.2-positive and -negative groups [median 18.4 versus 20.1 months; hazard ratio 1.26 (95% confidence interval 0.89-1.78); P = 0.191] regardless of stratification by PD-L1 CPS ≥5. Progression-free survival and objective response rates of first- and second-line chemotherapy, and anti-PD-1 therapy also showed no significant differences according to CLDN18.2 status.

CONCLUSIONS

CLDN18.2 expression in advanced GC/GEJC was associated with some clinical and molecular features but had no impact on treatment outcomes with chemotherapy or checkpoint inhibition. CLDN18.2-positive also had no impact on overall survival. This information could be useful to interpret the results from currently ongoing clinical trials of CLDN18.2-targeted therapies for advanced GC/GEJC and to consider a treatment strategy for CLDN18.2-positive GC/GEJC.

Predictive Validity of Different Walking Measures to Identify the Incident Long-Term Care Needs in Older Adults

OBJECTIVES

A comfortable walking speed is a suitable measurement of functional status in older adults. In addition to assessing their comfortable walking speed, two complex walking tests were administered to a cohort of older people, assuming that these tests would be a more sensitive predictor of the incident long-term care needs than comfortable walking speed.

DESIGN

A prospective observational study was conducted to collect data.

SETTING AND PARTICIPANTS

Among the initial 5,563 community-dwelling independent older adults (aged ≥ 65 years), 935 were excluded and the data of 4,628 (mean age, 73.9 ± 5.5 years, 65-94 years; 2,052 men, 2,576 women) older adults were finally analyzed.

METHODS

Three walking tasks were administered: comfortable, complicated balance, and Go-stop walking. Complicated balance walking was measured under comfortable walking conditions, with participants having to walk with their hands crossed at the shoulder joint at 90°. For the Go-stop walking test, the time taken to walk 2 meters was measured using a stopwatch. For two years following baseline assessments, participants received monthly follow-ups for incident certification of the need for care under the long-term care insurance (LTCI) system.

RESULTS

Low performance in comfortable, complicated balance, and Go-stop walking were 29.8%, 37.7%, and 35.1%, respectively. During the 24-month follow-up period, 246 participants (5.3%) required LTCI certification. The Youden Index was used to determine the cut-points of the incident long-term care needs in the comfortable, complicated balance, and Go-stop walking conditions, which were 1.055 m/s, 0.936 m/s, and 3.205 seconds, respectively. Participants classified as exhibiting low performance included 1,381 (29.8%) under comfortable walking, 1,746 (37.7%) under complicated balance walking, and 1,623 (35.1%) under the Go-stop walking tests. The C-indices of the comfortable, complicated balance, and Go-stop walking tests were 0.72 (95% confidence interval (CI) 0.69-0.76), 0.71 (95% CI 0.67-0.74), and 0.65 (95% CI 0.61-0.69), respectively. Cox proportional hazards regression model revealed significant relationships between the incident long-term care needs and the comfortable (hazard ratio (HR) 2.14, 95% CI 1.62-2.84), complicated balance (1.81, 1.36-2.41), and Go-stop (1.46, 1.12-1.91) walking conditions.

CONCLUSIONS AND IMPLICATIONS

The findings suggest that slow walking speed has a considerably greater impact on the incident long-term care needs in older adults. However, the complex walking task did not improve the predictive performance. Comfortable walking speed tests, which can easily be measured to predict the future incident long-term care needs, are effective tools in community health promotion and primary care.

Phase I study of the irreversible fibroblast growth factor receptor 1-4 inhibitor futibatinib in Japanese patients with advanced solid tumors

This phase I study was designed to: (1) determine the maximum tolerated dose (MTD) and recommended dose (RD) of the fibroblast growth factor receptor (FGFR) inhibitor futibatinib in Japanese patients with advanced solid tumors, and (2) examine the antitumor activity of the RD in patients with gastric cancer (GC) or other advanced solid tumors who have FGFR or FGF/FGFR abnormalities, respectively. In the dose-escalation phase, patients were assigned to 21-day cycles of oral futibatinib 8-160 mg three times a week (TIW) or 16 or 20 mg once daily (QD). In the expansion phase, patients received oral futibatinib 56, 80, or 120 mg TIW, or 16 or 20 mg QD. Eighty-three patients received futibatinib TIW (n = 40) or QD (n = 43). No dose-limiting toxicities were observed according to the final study protocol definition, and the MTD was not reached. The most common adverse events with both regimens were hyperphosphatemia (TIW, 82.5%; QD, 100.0%) and decreased appetite (TIW, 40.0%; QD, 58.1%). Hyperphosphatemia was asymptomatic, not leading to futibatinib discontinuation. The overall response rate (ORR) was 11.5% in patients with FGF/FGFR abnormalities. Notably, in GC patients harboring FGFR2 copy number (CN) ≥10, the ORR was 36.4% versus 0 in patients with CN <10. Therefore, futibatinib had a generally predictable and manageable safety profile in patients with advanced solid tumors. Antitumor activity was seen in patients with FGF/FGFR abnormalities, particularly those with GC and high FGFR2 CNs. Thus, futibatinib 20 mg QD was chosen as the RD for phase II studies.

Preclinical Characterization and Phase I Study of an Anti-HER2-TLR7 Immune-Stimulator Antibody Conjugate in Patients with HER2+ Malignancies

Immune-stimulator antibody conjugates (ISAC) combining tumor-targeting monoclonal antibodies with immunostimulatory agents allow targeted delivery of immune activators into tumors. NJH395 is a novel, first-in-class ISAC comprising a Toll-like receptor 7 (TLR7) agonist conjugated to an anti-HER2 antibody via a noncleavable linker payload. Preclinical characterization showed ISAC-mediated activation of myeloid cells in the presence of antigen-expressing cancer cells, with antigen targeting and TLR7 agonism contributing to antitumor activity. Safety, efficacy, immunogenicity, pharmacokinetics, and pharmacodynamics were investigated in a phase I, multicenter, open-label study in patients with HER2+ non-breast advanced malignancies (NCT03696771). Data from 18 patients enrolled in single ascending dose escalation demonstrated delivery of the TLR7-agonist payload in HER2+ tumor cells and induction of type I IFN responses, which correlated with immune modulation in the tumor microenvironment. Cytokine release syndrome was a common, but manageable, drug-related adverse event. Antidrug antibodies and neuroinflammation at high doses represented significant clinical challenges. Data provide proof-of-mechanism and critical insights for novel immunotherapies.

Pooled safety analysis from phase III studies of trifluridine/tipiracil in patients with metastatic gastric or gastroesophageal junction cancer and metastatic colorectal cancer

BACKGROUND

Trifluridine/tipiracil (FTD/TPI) showed clinical benefit, including improved survival and manageable safety in previously treated patients with metastatic colorectal (mCRC) or gastric/gastroesophageal junction (mGC/GEJC) cancer in the phase III RECOURSE and TAGS trials, respectively. A pooled analysis was conducted to further characterize FTD/TPI safety, including management of haematologic toxicities and use in patients with renal or hepatic impairment.

PATIENTS AND METHODS

Adults with ≥2 prior regimens for advanced mGC/GEJC or mCRC were randomized (2 : 1) to FTD/TPI [35 mg/m² twice daily days 1-5 and 8-12 (28-day cycle); same dosage in both trials] or placebo plus best supportive care. Adverse events (AEs) were summarized in the safety population (patients who received ≥1 dose) and analysed by renal/hepatic function.

RESULTS

TAGS and RECOURSE included 335 and 533 FTD/TPI-treated and 168 and 265 placebo-treated patients, respectively. Overall safety of FTD/TPI was similar in TAGS and RECOURSE. Haematologic (neutropenia, anaemia) and gastrointestinal (nausea, diarrhoea) AEs were most commonly observed. Laboratory-assessed grade 3-4 neutropenia occurred in 37% (TAGS)/38% (RECOURSE) of FTD/TPI-treated patients (median onset: 29 days/55 days), and 96% (TAGS)/97% (RECOURSE) of cases resolved regardless of renal/hepatic function. Supportive medications for neutropenia were received by 17% (TAGS) and 9% (RECOURSE); febrile neutropenia was reported in 2% and 4%, respectively. Overall grade ≥3 AEs were more frequent in patients with moderate renal impairment [81% (TAGS); 85% (RECOURSE)] versus normal renal function (74%; 67%); anaemia and neutropenia were more common in patients with renal impairment. FTD/TPI safety (including haematologic AEs) was consistent across patients with normal and mildly impaired hepatic function.

CONCLUSIONS

These results support FTD/TPI as a well-tolerated treatment in patients with mGC/GEJC or mCRC, with a consistent safety profile. Safety was largely similar in patients with normal or mildly impaired renal/hepatic function; however, patients with renal impairment should be monitored for haematologic toxicities.

Safety, Tolerability, and Pharmacokinetics of TAK-931, a Cell Division Cycle 7 Inhibitor, in Patients with Advanced Solid Tumors: A Phase I First-in-Human Study

Purpose:

We conducted a first-in-human, dose-escalation study, to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics, and activity of TAK-931, a cell division cycle 7 inhibitor, in Japanese patients with advanced solid tumors.

Experimental Design:

Patients ages ≥20 years received oral TAK-931: once daily for 14 days in 21-day cycles (schedule A; from 30 mg); once daily or twice daily for 7 days on, 7 days off in 28-day cycles (schedule B; from 60 mg); continuous once daily (schedule D; from 20 mg); or once daily for 2 days on, 5 days off (schedule E; from 100 mg) in 21-day cycles.

Results:

Of the 80 patients enrolled, all had prior systemic treatment and 86% had stage IV disease. In schedule A, 2 patients experienced dose-limiting toxicities (DLTs) of grade 4 neutropenia and the maximum tolerated dose (MTD) was 50 mg. In schedule B, 4 patients experienced DLTs of grade 3 febrile neutropenia (n = 3) or grade 4 neutropenia (n = 1); the MTD was 100 mg. Schedules D and E were discontinued before MTD determination. The most common adverse events were nausea (60%) and neutropenia (56%). Time to maximum plasma concentration of TAK-931 was approximately 1–4 hours postdose; systemic exposure was approximately dose proportional. Posttreatment pharmacodynamic effects correlating to drug exposure were observed. Overall, 5 patients achieved a partial response.

Conclusions:

TAK-931 was tolerable with a manageable safety profile. TAK-931 50 mg once daily days 1–14 in 21-day cycles was selected as a recommended phase II dose and achieved proof of mechanism.

Trial registration ID:

NCT02699749

Significance:

This was the first-in-human study of the CDC7 inhibitor, TAK-931, in patients with solid tumors. TAK-931 was generally tolerable with a manageable safety profile. The recommend phase II dose was determined to be TAK-931 50 mg administered once daily on days 1–14 of each 21-day cycle. A phase II study is ongoing to confirm the safety, tolerability, and antitumor activity of TAK-931 in patients with metastatic solid tumors.

First-in-human study of an OX40 (ivuxolimab) and 4-1BB (utomilumab) agonistic antibody combination in patients with advanced solid tumors

BACKGROUND

Ivuxolimab (PF-04518600) and utomilumab (PF-05082566) are humanized agonistic IgG2 monoclonal antibodies against OX40 and 4-1BB, respectively. This first-in-human, multicenter, open-label, phase I, dose-escalation/dose-expansion study explored safety, tolerability, pharmacokinetics, pharmacodynamics, and antitumor activity of ivuxolimab+utomilumab in patients with advanced solid tumors.

METHODS

Dose-escalation: patients with advanced bladder, gastric, or cervical cancer, melanoma, head and neck squamous cell carcinoma, or non-small cell lung cancer (NSCLC) who were unresponsive to available therapies, had no standard therapy available or declined standard therapy were enrolled into five dose cohorts: ivuxolimab (0.1-3 mg/kg every 2 weeks (Q2W)) intravenously plus utomilumab (20 or 100 mg every 4 weeks (Q4W)) intravenously. Dose-expansion: patients with melanoma (n=10) and NSCLC (n=20) who progressed on prior anti-programmed death receptor 1/programmed death ligand-1 and/or anti-cytotoxic T-lymphocyte-associated antigen 4 (melanoma) received ivuxolimab 30 mg Q2W intravenously plus utomilumab 20 mg Q4W intravenously. Adverse events (AEs) were graded per National Cancer Institute Common Terminology Criteria for Adverse Events V.4.03 and efficacy was assessed using Response Evaluation Criteria in Solid Tumors (RECIST) V.1.1 and immune-related RECIST (irRECIST). Paired tumor biopsies and whole blood were collected to assess pharmacodynamic effects and immunophenotyping. Whole blood samples were collected longitudinally for immunophenotyping.

RESULTS

Dose-escalation: 57 patients were enrolled; 2 (3.5%) patients with melanoma (0.3 mg/kg+20 mg and 0.3 mg/kg+100 mg) achieved partial response (PR), 18 (31.6%) patients achieved stable disease (SD); the disease control rate (DCR) was 35.1% across all dose levels. Dose-expansion: 30 patients were enrolled; 1 patient with NSCLC achieved PR lasting &gt;77 weeks. Seven of 10 patients with melanoma (70%) and 7 of 20 patients with NSCLC (35%) achieved SD: median (range) duration of SD was 18.9 (13.9-49.0) weeks for the melanoma cohort versus 24.1 (14.3-77.9+) weeks for the NSCLC cohort; DCR (NSCLC) was 40%. Grade 3-4 treatment-emergent AEs were reported in 28 (49.1%) patients versus 11 (36.7%) patients in dose-escalation and dose-expansion, respectively. There were no grade 5 AEs deemed attributable to treatment. Ivuxolimab area under the concentration-time curve increased in a dose-dependent manner at 0.3-3 mg/kg doses.

CONCLUSIONS

Ivuxolimab+utomilumab was found to be well tolerated and demonstrated preliminary antitumor activity in selected groups of patients.

TRIAL REGISTRATION NUMBER

NCT02315066.

The effect of achieving LDL-C &lt;1.8 mmol/L to prevent the first atherosclerotic cardiovascular events in the primary prevention settings of severe heterozygous familial hypercholesterolemia

Introduction

The International Atherosclerosis Society (IAS) has proposed “severe familial hypercholesterolemia” (FH) as a phenotype with the highest cardiovascular risk. LDL-C &lt;2.5 mmol/l is a recommended therapeutic goal for the primary prevention settings of severe FH. However, given that ESC guidelines recommends LDL-C &lt;1.8 mmol/l in FH patients, this stricter goal may be better to prevent the first atherosclerotic cardiovascular disease (ASCVD) in severe FH patients.

Purpose

To determine whether achieving LDL-C&lt;1.8 mg/dl is more beneficial to reduce the first ASCVD events.

Methods

A total of 148 severe FH subjects without any history of ASCVD were analyzed. Severe FH was defined as untreated LDL-C &gt;10.3 mmol/l, LDL-C &gt;8.0 mmol/l+ 1 high-risk feature, LDL-C &gt;4.9 mmol/l + 2 high-risk features according to IAS proposed statement. The occurrence of ASCVD (all-cause death, CAD, ischemic stroke and lower extremity artery disease (LEAD)) were compared in those with on-treatment LDL-C &lt; and ≥1.8 mmol/L.

Results

10.1% (=15/148) of study subjects achieved on-treatment LDL-C &lt;1.8 mmol/l. They were more likely to receive PCSK9 inhibitor (15.0 vs. 66.7%, p&lt;0.01), whereas there was no significant difference in FH-related physical characteristics (tendon xanthomas: 72.2 vs. 93.3%, p=0.12) and causative genotypes (LDLR: 68.4 vs. 66.7%, p=1.00, PCSK9: 8.3 vs. 6.7%, p=1.00, LDLR/PCSK9: 3.8 vs. 6.7%, p=0.48), untreated LDL-C (7.3±1.7 vs. 7.9±1.8 mmol/l, p=0.22) and lipoprotein(a) (23 [11–42] vs. 25 [15–70] mg/dl, p=0.41) levels between two groups. During the observational period (median=7.0 years), severe FH achieving on-treatment LDL-C &lt;1.8 mmol/l was associated with a lower likelihood of experiencing ASCVD events (Figure 1). Of note, any cardiovascular events did not occur in severe FH who achieved on-treatment LDL-C &lt;1.8 mmol/l. In those with on-treatment LDL ≥1.8 mmol/L, CAD (76.5%=26/34) was more dominant component of ASCVD, followed by ischemic stroke (17.6%=6/34) and LEAD (5.9%=2/34).

Conclusions

A significantly lower frequency of ASCVD was observed in severe FH who achieved LDL-C &lt;1.8 mmol/L in the primary prevention settings. Given that only 10.1% of severe FH patients achieved LDL-C &lt;1.8 mmol/l, more actions are required to motivate physicians for further intensified management of LDL-C in severe FH patients in the primary prevention settings.

Funding Acknowledgement

Type of funding sources: None.

Updated Efficacy Outcomes of Anti-PD-1 Antibodies plus Multikinase Inhibitors for Patients with Advanced Gastric Cancer with or without Liver Metastases in Clinical Trials

PURPOSE

We previously reported preliminary activity of regorafenib plus nivolumab (REGONIVO) or lenvatinib plus pembrolizumab (LENPEM) in advanced gastric cancer (AGC). Meanwhile, several studies demonstrated liver metastases are less responsive to immunotherapy.

PATIENTS AND METHODS

Combined efficacy outcomes with a longer follow-up in a phase Ib trial of REGONIVO and a phase II trial of LENPEM were examined in AGC with or without liver metastases (REGONIVO plus LENPEM cohort). We also investigated the efficacy of anti-PD-1 monotherapies (anti-PD-1 monotherapy cohort). A comparison of the immune microenvironment between gastric primary tumors and liver metastases was also conducted by multiplex IHC.

RESULTS

In the REGONIVO plus LENPEM cohort, with a median follow-up of 14.0 months, objective response rate (ORR), median progression-free survival (mPFS), and median overall survival (mOS) were 46%, 7.8 months, and 15.6 months in patients with liver metastases, while 69%, 6.9 months, and 15.5 months in those without. In the anti-PD-1 monotherapy cohort, with a median follow-up of 27.6 months, ORR, mPFS, and mOS were 9%, 1.4 months, and 6.4 months in patients with liver metastases, while 22%, 2.3 months, and 9.0 months in those without. Multiplex IHC revealed liver metastases were associated with an abundance of immune-suppressive cells, such as tumor-associated macrophages and regulatory T cells, with fewer CD8+ T cells compared with gastric primary tumors.

CONCLUSIONS

Anti-PD-1 antibodies plus regorafenib or lenvatinib for AGC showed promising antitumor activity with a longer follow-up, irrespective of liver metastases status, despite a more immune-suppressive tumor microenvironment in liver metastases.

Utomilumab in Patients With Immune Checkpoint Inhibitor-Refractory Melanoma and Non-Small-Cell Lung Cancer

Section Head

Clinical/translational cancer immunotherapy

Background

The goal of this study was to estimate the objective response rate for utomilumab in adults with immune checkpoint inhibitor (ICI)-refractory melanoma and non–small-cell lung cancer (NSCLC).

Methods

Utomilumab was dosed intravenously every 4 weeks (Q4W) and adverse events (AEs) monitored. Tumor responses by RECIST1.1 were assessed by baseline and on-treatment scans. Tumor biopsies were collected for detection of programmed cell death ligand 1, CD8, 4-1BB, perforin, and granzyme B, and gene expression analyzed by next-generation sequencing. CD8+ T cells from healthy donors were stimulated with anti-CD3 ± utomilumab and compared with control.

Results

Patients with melanoma (n=43) and NSCLC (n=20) received utomilumab 0.24 mg/kg (n=36), 1.2 mg/kg (n=26), or 10 mg/kg (n=1). Treatment-emergent AEs (TEAEs) occurred in 55 (87.3%) patients and serious TEAEs in 18 (28.6%). Five (7.9%) patients discontinued owing to TEAEs. Thirty-two (50.8%) patients experienced treatment-related AEs, mostly grade 1–2. Objective response rate: 2.3% in patients with melanoma; no confirmed responses for patients with NSCLC. Ten patients each with melanoma (23.3%) or NSCLC (50%) had stable disease; respective median (95% confidence interval, CI) progression-free survival was 1.8 (1.7–1.9) and 3.6 (1.6–6.5) months. Utomilumab exposure increased with dose. The incidences of antidrug and neutralizing antibodies were 46.3% and 19.4%, respectively. Efficacy was associated with immune-active tumor microenvironments, and pharmacodynamic activity appeared to be blunted at higher doses.

Conclusions

Utomilumab was well tolerated, but antitumor activity was low in patients who previously progressed on ICIs. The potential of 4-1BB agonists requires additional study to optimize efficacy while maintaining the tolerable safety profile.

Eftozanermin alfa (ABBV-621) monotherapy in patients with previously treated solid tumors: findings of a phase 1, first-in-human study

Eftozanermin alfa (eftoza), a second-generation tumor necrosis factor-related apoptosis-inducing ligand receptor (TRAIL-R) agonist, induces apoptosis in tumor cells by activation of death receptors 4/5. This phase 1 dose-escalation/dose-optimization study evaluated the safety, pharmacokinetics, pharmacodynamics, and preliminary activity of eftoza in patients with advanced solid tumors. Patients received eftoza 2.5-15 mg/kg intravenously on day 1 or day 1/day 8 every 21 days in the dose-escalation phase, and 1.25-7.5 mg/kg once-weekly (QW) in the dose-optimization phase. Dose-limiting toxicities (DLTs) were evaluated during the first treatment cycle to determine the maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D). Pharmacodynamic effects were evaluated in circulation and tumor tissue. A total of 105 patients were enrolled in the study (dose-escalation cohort, n = 57; dose-optimization cohort, n = 48 patients [n = 24, colorectal cancer (CRC); n = 24, pancreatic cancer (PaCA)]). In the dose-escalation cohort, seven patients experienced DLTs. MTD and RP2D were not determined. Most common treatment-related adverse events were increased alanine aminotransferase and aspartate aminotransferase levels, nausea, and fatigue. The one treatment-related death occurred due to respiratory failure. In the dose-optimization cohort, three patients (CRC, n = 2; PaCA, n = 1) had a partial response. Target engagement with regard to receptor saturation, and downstream apoptotic pathway activation in circulation and tumor were observed. Eftoza had acceptable safety, evidence of pharmacodynamic effects, and preliminary anticancer activity. The 7.5-mg/kg QW regimen was selected for future studies on the basis of safety findings, pharmacodynamic effects, and biomarker modulations. (Trial registration number: NCT03082209 (registered: March 17, 2017)).

Evaluation of pembrolizumab monotherapy in patients with previously treated advanced salivary gland carcinoma in the phase 2 KEYNOTE-158 study

AIM

We evaluated pembrolizumab monotherapy in patients with advanced salivary gland carcinoma on the phase 2 KEYNOTE-158 study (NCT02628067).

METHODS

Eligible patients had histologically/cytologically confirmed advanced salivary gland carcinoma with prior failure or intolerance to standard therapy, measurable disease per Response Evaluation Criteria in Solid Tumours (RECIST) v1.1., and ECOG performance status 0-1. Patients were enrolled irrespective of tumour PD-L1 expression. Patients received pembrolizumab 200 mg Q3W for up to 35 cycles (∼2 years). Radiographic imaging occurred every 9 weeks through month 12, then every 12 weeks. PD-L1 positivity was defined as combined positive score ≥1 (evaluated using PD-L1 IHC 22C3 pharmDx). The primary endpoint was objective response rate per RECIST v1.1.

RESULTS

In total, 109 patients were enrolled (PD-L1-positive, 25.7%). At the data cutoff (October 5, 2020), median follow-up was 53.3 (range, 50.8-56.3) months. Objective response rate was 4.6% (95% CI, 1.5-10.4%) among all patients (complete response, n = 1; partial response, n = 4) and was 10.7% (95% CI, 2.3-28.2%) in patients with PD-L1-positive disease and 2.6% (95% CI, 0.3-9.1%) in patients with PD-L1-negative disease. Duration of response was ≥24 months for all 5 responders; median duration of response was not reached (range, 25.1-49.8+ months). Median progression-free survival and overall survival were 4.0 (95% CI, 2.6-4.2) and 21.1 (95% CI, 15.9-25.5) months, respectively. Treatment-related adverse events occurred in 75.2% (grade 3-4, 15.6%; grade 5, 0%) of patients. Immune-mediated adverse events occurred in 22.0% of patients (grade 3, 5.5%; grade 4-5, 0).

CONCLUSIONS

A small subset of patients with advanced salivary gland carcinoma treated with pembrolizumab had a response; all had response duration ≥2 years. The safety profile of pembrolizumab was manageable.

Characteristics and clinical outcomes of patients with advanced gastric or gastroesophageal cancer treated in and out of randomized clinical trials of first-line immune checkpoint inhibitors

BACKGROUND

Although several randomized trials (RCTs) showed survival benefits of immune checkpoint inhibitor (ICI) plus first-line chemotherapy for advanced gastric or gastroesophageal cancer (AGC), these trials could enroll patients who fulfilled the strict eligibility criteria or waited for certain screening period for central assessment of PD-L1 status.

METHODS

We retrospectively compared characteristics and clinical outcomes of the patients with AGC who received first-line chemotherapy in control arm of RCTs with ICIs (control group) or clinical practice (practice group) at our institution from February 2016 to April 2019.

RESULTS

The control group had a better baseline Eastern Cooperative Oncology Group performance status (PS0, 81.2% vs. 51.4%, p < 0.001) and a longer interval from first visit to first-line chemotherapy initiation (19 days vs. 9 days, p < 0.001) than the practice group. Median overall survival (OS) was 20.3 months in control group and 15.7 months in practice group, with a trend of longer OS in control group than that in practice group (hazard ratio, 0.71; p = 0.062). More patients in control group were treated with subsequent chemotherapy including ICIs.

CONCLUSION

Patients with AGC in RCTs of ICIs had a better PS or a higher chance to receive subsequent chemotherapy, resulting in a better prognosis than those treated in clinical practice. This information should be considered when interpreting RCT results and applying new treatments into clinical practice.

Abstract CT514: A phase I, open-label, dose-escalation study investigating a low-density lipoprotein receptor-related protein (LRP) 5/6 inhibitor, BI 905677, in patients with advanced solid tumors

Background: Ligand-dependent Wnt signaling, mediated by LRP5/6, is highly activated in a subset of solid tumors. Activation leads to accumulation of intracellular β-catenin and expression of β-catenin-dependent genes that promote cancer cell proliferation and treatment resistance. BI 905677 is a bi-paratopic antibody that binds LRP5/6 and blocks binding of Wnt ligands. This study (NCT03604445) aimed to identify the maximum tolerated dose (MTD) and determine the recommended dose for BI 905677 in patients with advanced solid tumors. Pharmacokinetics and efficacy will also be evaluated.

Methods: This is a Phase I, open-label, non-randomized study of BI 905677, administered intravenously, in patients with advanced, unresectable and/or metastatic solid tumors. Patients were refractory to or not eligible for standard therapy. Patients were treated at increasing intravenous doses of BI 905677 (0.05, 0.1, 0.2, 0.4, 0.8, 1.6, 2.4, 2.8 and 3.6 mg/kg every 3 weeks [q3w]) until progression. Subsequent patients within a cohort were treated ≥ 72 hours apart to allow adequate monitoring for cytokine release syndrome and implementation of preventive measures if required.

Results: As of November 23, 2021, 37 patients have received BI 905677. The median age was 56 years (range 32-77) and most were male (65%) and had ECOG PS 1 (51%). At 3.6 mg/kg, 3/3 patients experienced dose-limiting toxicities (DLTs) and dose was reduced to 2.8 mg/kg, which was determined as the MTD. Patients received a median of 2.0 cycles (range 1-6). Across all dose levels, 19 patients (51%) experienced Grade ≥ 3 adverse events (AEs). The most common Grade ≥ 3 AEs were vomiting (11%), hyponatremia (8%), anemia (5%), diarrhea (5%), abdominal pain (5%), nausea (5%), hypokalemia (5%), pain (5%) and increased alkaline phosphatase (5%). No related Grade ≥ 3 AEs were reported for doses ≤ 1.6 mg/kg, and BI 905677 was considered well tolerated ≤ 2.8 mg/kg. There were two Grade 5 events not related to study drug (tumor lysis syndrome and disease progression). DLTs observed at 3.6 mg/kg were hyponatremia, increased β-CTX expression (&gt; 2-fold versus baseline), diarrhea, hyperbilirubinemia and vomiting. Exposure to BI 905677 increased in an approximately dose-proportional manner over the complete dose groups tested. No drug accumulation between Cycle 1 and Cycle 2 was observed for any cohort. Only six patients presented with anti-drug antibodies (ADAs), including one with pre-existing ADAs. Axin2 expression by reverse transcription PCR was reduced in paired skin biopsies but no dose dependency was observed. Across all doses, the best response was stable disease (n = 13; 35%).

Conclusions: BI 905677 was well tolerated, with the MTD established as 2.8 mg/kg q3w. An expansion cohort to evaluate the activity of BI 905677 in a molecularly selected population for Wnt ligand dependence is planned.

Citation Format: Elena Élez, Heinz-Josef Lenz, Maja de Jonge, Rona Yaeger, Toshihiko Doi, Linda Pronk, Michael Teufel, Kristell Marzin, Josep Tabernero. A phase I, open-label, dose-escalation study investigating a low-density lipoprotein receptor-related protein (LRP) 5/6 inhibitor, BI 905677, in patients with advanced solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT514.

Abstract 5185: First in human trial of off-the shelf iPS derived anti-GPC3 NK cells for recurrent ovarian clear cell carcinoma with peritoneal dissemination

Background: The development of chimeric antigen receptor (CAR) T cell therapy has introduced an effective strategy to guide and promote the immune response. Also, gene-engineering NK cells to express an exogenous CAR receptor allows the innate anti-tumor ability of NK cells to be directed against target tumor antigen. However, these autologous applications are limited by toxicities, restricted trafficking and infiltration into tumor, suboptimal persistence, and exhausted status of immune cells that may cause manufacturing failure. One approach to overcome those limitations is the development of “off-the-shelf” iPS-cell sources. The iCAR-ILC-N101 is an allogeneic human leukocyte antigen (HLA)-homozygous induced pluripotent stem cell (iPSC)-derived anti-glypican-3 (GPC3) CAR-expressing innate lymphoid cells/natural killer cell (ILC/NK), which has both antigen-specific and NK activating receptor-mediated cytotoxicity. The iCAR-ILC-N101 is produced from the established iPSC strain QHJI01s04, and there is theoretically no risk of developing graft-versus host disease because the product dose not have T cell receptor. The product has a relevant living period in the body, thereby has little concern about residual toxicity and reduces systemic side effects by topical treatment. GPC3 is a cancer-specific membranous protein that is expressed in hepatoblastoma, hepatocellular carcinoma and ovarian clear cell carcinoma (OCCC) but is not expressed in normal tissue. OCCC is a relatively rare malignancy and is associated with poor prognosis. Intraperitoneal administration of iCAR-ILC-N101 is expected to show antitumor activity for OCCC patients with peritoneal dissemination that express GPC3 and reduce systemic side effects, thereby ensuring safety and improving therapeutic efficacy. Preclinical study showed that intraperitoneal injection of iCAR-ILC-N101 for GPC3-positive ovarian tumor-bearing immunodeficient mouse model showed suppressed tumor growth.

Method: This is a first-in human phase 1 study to evaluate safety, toxicity and efficacy of the iCAR-ILC-N101 in patients with GPC3-positive advanced or recurrent OCCC harboring peritoneal dissemination. Major inclusion criteria include histologically diagnosed GPC3-positive advanced or recurrent OCCC with peritoneal dissemination who are resistant to standard therapy and have matched HLA-A24 or B52. The study includes 3 cohorts (cohort -1, 0.5x106 cells/kg; cohort 1, 1x106 cells/kg; cohort 2, 3x106 cells/kg) and starts with cohort 1. The iCAR-ILC-N101 is administered intraperitoneally once a week for 4 weeks; for the first patient in each cohort, patient is observed for 14 days for safety evaluation after the first administration and then receive iCAR-ILC-N101 on day15 and 22. Enrollment initiated in July 2021 and one patient was enrolled. No dose-limiting toxicity was observed. Clinical trial registry number: jRCT2033200431

Citation Format: Kenichi Harano, Shin Kaneko, Tetsuya Nakatsura, Junichiro Yuda, Nozomu Fuse, Akihiro Sato, Reiko Watanabe, Genichiro Ishii, Toru Mukohara, Hiroshi Tanabe, Yukiko Ishiguro, Hideki Furuya, Masashi Wakabayashi, Miki Fukutani, Manami Shimomura, Tatsuki Ueda, Shoichi Iriguchi, Ayako Kumagai, Kengo Nakagoshi, Aki Sasaki, Toshihiko Doi. First in human trial of off-the shelf iPS derived anti-GPC3 NK cells for recurrent ovarian clear cell carcinoma with peritoneal dissemination [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5185.

Pimitespib in patients with advanced gastrointestinal stromal tumor (CHAPTER-GIST-301): a randomized, double-blind, placebo-controlled phase 3 trial

BACKGROUND

Prognosis of advanced gastrointestinal stromal tumors (GIST) refractory to tyrosine kinase inhibitors (TKIs) is poor. This randomized, placebo-controlled, phase 3 trial evaluated the efficacy and safety of pimitespib, a novel heat shock protein 90 inhibitor, in advanced GIST refractory to standard TKIs.

PATIENTS AND METHODS

Patients with histologically confirmed GIST refractory to imatinib, sunitinib, and regorafenib were randomized 2:1 to oral pimitespib 160 mg/day or placebo for five consecutive days per week in 21-day cycles. Following disease progression by blinded central radiological review (BCRR), crossover to open-label pimitespib was permitted. The primary endpoint was progression-free survival (PFS) by BCRR in the full analysis set. Secondary endpoints included overall survival (OS) adjusted using the rank preserving structural failure time method to reduce the expected confounding impact of crossover.

RESULTS

From Oct 31, 2018 to Apr 30, 2020, 86 patients were randomized to pimitespib (n=58) or placebo (n=28). Median PFS was 2.8 months (95% CI 1.6-2.9) with pimitespib versus 1.4 months (0.9-1.8) with placebo (hazard ratio [HR] 0.51 [95% CI 0.30-0.87]; one-sided p=0.006). Pimitespib showed an improvement in crossover-adjusted OS compared with placebo (HR 0.42 [0.21-0.85], one-sided p=0.007). Seventeen (60.7%) patients receiving placebo crossed-over to pimitespib; median PFS after crossover was 2.7 (95% CI 0.7-4.1) months. The most common (≥30%) treatment-related adverse events (AEs) with pimitespib were diarrhea (74.1%) and decreased appetite (31.0%); the most common (≥10%) grade ≥3 treatment-related AE was diarrhea (13.8%). Treatment-related AEs leading to pimitespib discontinuation occurred in 3 (5.2%) patients.

CONCLUSION

Pimitespib significantly improved PFS and crossover-adjusted OS compared with placebo and had an acceptable safety profile in patients with advanced GIST refractory to standard TKIs.

First-line lenvatinib plus pembrolizumab plus chemotherapy in esophageal squamous cell carcinoma: LEAP-014 trial in progress

TPS4167

Background: Recent data from the KEYNOTE-590 study demonstrated the superiority of pembrolizumab plus chemotherapy compared with chemotherapy as first-line treatment for unresectable locally advanced recurrent or metastatic adenocarcinoma or squamous cell carcinoma of the esophagus, or advanced/metastatic Siewert type 1 adenocarcinoma of the gastroesophageal junction. Prior data also suggest promising antitumor activity of lenvatinib plus pembrolizumab in advanced solid tumors. LEAP-014 (NCT04949256) is a randomized, 2-part, open-label, phase 3 study that will evaluate the efficacy and safety of first-line lenvatinib plus pembrolizumab plus chemotherapy versus pembrolizumab plus chemotherapy in patients with metastatic esophageal squamous cell carcinoma (ESCC). Methods: Key eligibility criteria include histologically or cytologically confirmed metastatic ESCC, measurable disease per Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST v1.1), and Eastern Cooperative Oncology Group performance status 0 to 1. In part 1 (safety run-in), ̃6 patients will be treated for induction with intravenous (IV) pembrolizumab 400 mg every 6 weeks (Q6W) for 2 cycles plus oral lenvatinib 8 mg daily (QD) plus IV 5-fluorouracil (FU; 4000 mg/m2 on days 1-5) plus IV cisplatin (80 mg/m2) (FP) for 4 cycles and treated for consolidation with pembrolizumab 400 mg Q6W for ≤16 doses plus lenvatinib 20 mg QD; patients will be closely monitored for 21 days after the first dose of study intervention for dose-limiting toxicities. In part 2 (main study), approximately 850 patients will be randomly assigned 1:1 to induction with pembrolizumab plus lenvatinib plus chemotherapy (FP or mFOLFOX6 [Q2W for 6 cycles {IV oxaliplatin 85 mg/m2 plus bolus IV 5-FU 400 mg/m2 plus continuous IV 5-FU 2400 mg/m2 plus IV leucovorin 400 mg/m2 or IV levoleucovorin 200 mg/m2}]) followed by consolidation with pembrolizumab plus lenvatinib (arm 1) or pembrolizumab plus chemotherapy (FP or mFOLFOX6; arm 2). Randomization will be stratified by PD-L1 combined positive score (CPS; ≥10 vs < 10), region (East Asia vs North America and Western Europe vs rest of world), and chemotherapy backbone (FP vs mFOLFOX6). Treatment will continue until disease progression, unacceptable toxicity, or withdrawal of consent. Tumor imaging assessment will be performed Q6W for ≤1 year and Q9W thereafter. In part 1, the primary end point is safety and tolerability. In part 2, the dual primary end points are overall survival and progression-free survival (per RECIST v1.1 assessed by blinded independent central review [BICR]); secondary end points include objective response rate and duration of response (per RECIST v1.1 assessed by BICR) and safety and tolerability. Enrollment in this trial is ongoing. Clinical trial information: NCT04949256.

Tumor agnostic efficacy and safety of erdafitinib in patients (pts) with advanced solid tumors with prespecified fibroblast growth factor receptor alterations (FGFRalt) in RAGNAR: Interim analysis (IA) results

3007

Background: Erdafitinib (erda) is an oral selective pan-FGFR tyrosine kinase inhibitor approved to treat locally advanced or metastatic urothelial carcinoma (UC) in adults with susceptible FGFR3/2alt who have progressed during or after ≥ 1 line of platinum containing chemotherapy . FGFRalt are observed across a wide range of malignancies and may function as oncogenic drivers independent of the underlying tumor type. RAGNAR (NCT04083976) is an ongoing phase 2 open label, single arm tumor agnostic trial investigating the efficacy and safety of erda in pretreated adult and pediatric pts with advanced solid tumors and FGFRalt. Here, we report results from a planned IA of RAGNAR. Methods: Pts aged ≥ 6 y with advanced or metastatic solid tumors of any histology (except UC) with predefined FGFR1-4alt (mutations/fusions based on local/central test) and documented disease progression on ≥ 1 prior line of systemic therapy (tx) and no alternative standard tx received oral erda until disease progression or intolerable toxicity. The primary end point is objective response rate (ORR) by independent review committee (IRC). Secondary end points include investigator assessed ORR, duration of response (DOR), disease control rate (DCR), clinical benefit rate (CBR), PFS, OS, and treatment emergent adverse events (TEAEs). Results: As of the IA data cutoff, 178 pts were treated (median age 56.5 y [range 12-79], median 2 prior systemic tx). Only 9.0% of pts responded to last line of tx prior to study entry. ORR by IRC was 29.2% (95% CI, 22.7-36.5). Investigator assessed ORR was 26.4% (95% CI, 20.1-33.5). Responses were observed in 14 distinct tumor types, including gliomas, thoracic, gastrointestinal, gynecological, and rare tumors (Table). ORR in pts with FGFR mutations vs fusions was comparable (26.8% vs 27.0%, respectively). Median DOR, PFS, and OS were 7.1 mo (95% CI, 5.5-9.3), 5.2 mo (95% CI, 4.0-5.6), and 10.9 mo (95% CI, 7.9-14.3), respectively; DCR was 75.3% and CBR was 48.9%. All pts experienced TEAEs, including 69.1% with grade ≥ 3. Treatment-related serious TEAEs occurred in 7.3% of pts. Conclusions: RAGNAR data show, for the first time, evidence of efficacy for erda in heavily pretreated pts with a variety of hard to treat advanced FGFR+ malignancies, including glioblastoma, pancreatic, and salivary gland cancers. Safety was consistent with the known erda safety profile. Clinical trial information: NCT04083976. [Table: see text]

DS-7300 (B7-H3 DXd-ADC) in patients (pts) with metastatic castration-resistant prostate cancer (mCRPC): A subgroup analysis of a phase 1/2 multicenter study

87

Background: DS-7300 is an antibody drug conjugate with an exatecan derivative payload that targets B7-H3, which is overexpressed in various cancers. Initial findings from an ongoing phase 1/2 dose escalation study for advanced solid tumors, and dose-expansion studies in esophageal squamous cell carcinoma and mCRPC (NCT04145622) showed that DS-7300 was generally well tolerated with early signs of clinical activity (ESMO 2021, abstract 513O). Here, we present preliminary results from the mCRPC pt subset. Methods: This study consisted of 2 parts: dose- escalation (part 1) and expansion (part 2). Part 1 assessed the safety and tolerability of DS-7300 with doses ranging from 0.8 to 16 mg/kg. A dose of 12 mg/kg was selected for part 2. Part 2 assessed safety and prospective efficacy of DS-7300 in the selected tumor types, including mCRPC. DS-7300 was administered intravenously every 3 weeks in parts 1 and 2. Results: At data cutoff (August 8, 2021), 29 pts with mCRPC from the US and Japan were enrolled in parts 1 (n = 24) and 2 (n = 5). Pts enrolled in this study were heavily pretreated, with a median of 6.0 (range, 2-10) and 5.0 (range, 3-10) prior lines of therapy in parts 1 and 2, respectively. Baseline B7-H3 expression was highly prevalent in the study population. Enrolled pts were 44 to 82 years of age (median, 68.0 years) and had an ECOG performance status ≤1. Treatment-emergent adverse events (TEAEs) occurred in 29 pts (100.0%) in parts 1 and 2, with 7 pts (21.4%) with TEAEs leading to dose interruption, 2 pts (6.9%) with TEAEs leading to dose reduction, and no pts with TEAEs associated with drug discontinuation. The most common (≥20%) all-grade (Gr) TEAEs were nausea (65.5%), infusion-related reactions (IRRs; 34.5%), fatigue (34.5%), chills (31.0%), vomiting (31.0%), anemia (27.6%), diarrhea (27.6%), and dehydration (20.7%). Gr ≥3 TEAEs occurred in 10 pts (34.5%); the most common was anemia (17.2%). There were no Gr ≥3 treatment-related serious TEAEs (SAEs) reported. All IRR cases were Gr 1/2 and manageable with supportive care. No ILD/pneumonitis cases were reported. RECIST responses were observed in pts treated with DS-7300 between 6.4- and 16.0-mg/kg doses, including 6 partial responses (4 confirmed) and 15 stable diseases. The median duration of treatment was 13.9 weeks (range, 3-40 weeks) in part 1 and 6.0 weeks (range, 3-9.14 weeks) in part 2. At data cutoff, 8 pts (66.7%) in the 12.0-mg/kg group in part 1 and 4 pts (80.0%) in part 2 were ongoing treatment. Moreover, preliminary data indicate improvements in prostate-specific antigen (PSA) and bone metastases. Conclusions: DS-7300 was well tolerated with an acceptable safety profile in pts with mCRPC. The preliminary safety and efficacy data are encouraging and warrant further investigation. Clinical trial information: NCT04145622.

Lactic acid promotes PD-1 expression in regulatory T cells in highly glycolytic tumor microenvironments

The balance of programmed death-1 (PD-1)-expressing CD8⁺ T cells and regulatory T (Treg) cells in the tumor microenvironment (TME) determines the clinical efficacy of PD-1 blockade therapy through the competition of their reactivation. However, factors that determine this balance remain unknown. Here, we show that Treg cells gain higher PD-1 expression than effector T cells in highly glycolytic tumors, including MYC-amplified tumors and liver tumors. Under low-glucose environments via glucose consumption by tumor cells, Treg cells actively absorbed lactic acid (LA) through monocarboxylate transporter 1 (MCT1), promoting NFAT1 translocation into the nucleus, thereby enhancing the expression of PD-1, whereas PD-1 expression by effector T cells was dampened. PD-1 blockade invigorated the PD-1-expressing Treg cells, resulting in treatment failure. We propose that LA in the highly glycolytic TME is an active checkpoint for the function of Treg cells in the TME via upregulation of PD-1 expression.

LEAP-014: An open-label, randomized, phase 3 study of first-line lenvatinib plus pembrolizumab plus chemotherapy in esophageal squamous cell carcinoma

TPS367

Background: Recent data from the KEYNOTE-590 study demonstrated the superiority of pembrolizumab plus chemotherapy compared with chemotherapy as first-line treatment for unresectable locally advanced recurrent or metastatic adenocarcinoma or squamous cell carcinoma of the esophagus, or advanced/metastatic Siewert type 1 adenocarcinoma of the gastroesophageal junction. Prior data also suggest promising antitumor activity of lenvatinib plus pembrolizumab in advanced solid tumors. LEAP-014 (NCT04949256) is a randomized, 2-part, open-label, phase 3 study that will evaluate the efficacy and safety of first-line lenvatinib plus pembrolizumab plus chemotherapy versus pembrolizumab plus chemotherapy in patients with metastatic esophageal squamous cell carcinoma (ESCC). Methods: Key eligibility criteria include metastatic ESCC, measurable disease per Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST v1.1), and Eastern Cooperative Oncology Group performance status ≤1. In part 1 (safety run-in), ̃6 patients will be treated for induction with intravenous (IV) pembrolizumab 400 mg every 6 weeks (Q6W) for 2 cycles plus oral lenvatinib 8 mg daily (QD) plus IV 5-fluorouracil (FU; 4000 mg/m2 on days 1-5) plus IV cisplatin (80 mg/m2) (FP) for 4 cycles and treated for consolidation with pembrolizumab 400 mg Q6W for ≤16 doses plus lenvatinib 20 mg QD; patients will be closely monitored for 21 days after the first dose of study intervention for dose-limiting toxicities. Approximately 850 patients will be randomly assigned 1:1 to induction with pembrolizumab plus lenvatinib plus chemotherapy (FP or mFOLFOX6 [Q2W for 6 cycles {IV oxaliplatin 85 mg/m2 plus bolus IV 5-FU 400 mg/m2 plus continuous IV 5-FU 2400 mg/m2 plus IV leucovorin 400 mg/m2 or IV levoleucovorin 200 mg/m2}]) followed by consolidation with pembrolizumab plus lenvatinib (arm 1) or pembrolizumab plus chemotherapy (FP or mFOLFOX6; arm 2). Randomization will be stratified by PD-L1 combined positive score (CPS; ≥10 vs < 10), region (East Asia vs North America and Western Europe vs rest of world), and chemotherapy backbone (FP vs mFOLFOX6). Treatment will continue until disease progression, unacceptable toxicity, or withdrawal of consent. Tumor imaging assessment will be performed Q6W for ≤1 year and Q9W thereafter. In part 1, the primary end point is safety and tolerability. In part 2, the dual primary end points are overall survival and progression-free survival (per RECIST v1.1 assessed by blinded independent central review [BICR]); secondary end points include objective response rate and duration of response (per RECIST v1.1 assessed by BICR) and safety and tolerability. Clinical trial information: NCT04949256.

First-line pembrolizumab plus chemotherapy versus chemotherapy in advanced esophageal cancer: Longer-term efficacy, safety, and quality-of-life results from the phase 3 KEYNOTE-590 study

241

Background: At interim analysis of the phase 3, randomized, double-blind KEYNOTE-590 (NCT03189719) study, 1L pembrolizumab (pembro) + chemotherapy (chemo) vs chemo alone provided superior OS, PFS, and ORR with a manageable safety profile in patients (pts) with untreated, advanced/unresectable or metastatic adenocarcinoma or esophageal squamous cell carcinoma (ESCC) or Siewert type 1 esophagogastric junction adenocarcinoma (EGJ). We report efficacy, safety, and health-related quality of life (HRQoL) results with an additional 12 months (mo) of follow-up. Methods: 749 eligible pts were randomized 1:1 to pembro 200 mg or placebo Q3W for up to 2 yr + chemo. Randomization was stratified by geographic region, histology, and performance status. Treatment continued until progression, unacceptable toxicity, or withdrawal, or 2 yr. No crossover was permitted. Primary endpoints were OS in pts with ESCC PD-L1 combined positive score (CPS) ≥10 tumors, and OS and PFS (RECIST v1.1; by INV) in ESCC, PD-L1 CPS ≥10, and all pts. Secondary endpoints included ORR, DOR, safety, and HRQoL. HRQol was assessed in 711 treated pts with ≥1 HRQoL assessment (356 pembro + chemo; 355 chemo). Data cutoff was July 9, 2021. Results: At data cutoff, median follow-up (randomization to data cutoff) was 34.8 mo. Median OS was longer with pembro + chemo vs chemo in pts with ESCC CPS ≥10 (HR 0.59; 95% CI, 0.45-0.76), ESCC (HR 0.73; 95% CI, 0.61-0.88), CPS ≥10 (HR 0.64; 95% CI, 0.51-0.80), and all pts (HR 0.73, 95% CI, 0.63-0.86). In pts with adenocarcinoma OS HR was 0.73 (95% CI, 0.55-0.99). The 24-mo OS rate in all pts was 26.3% vs 16.1%. Median PFS was longer with pembro + chemo vs chemo in ESCC (HR 0.65; 95% CI, 0.54-0.78), CPS ≥10 (HR 0.51; 95% CI, 0.41-0.65), and all pts (HR 0.64; 95% CI, 0.55-0.75). The 24-mo PFS rate in all pts was 11.6% vs 3.3%. Confirmed ORR was 45.0% (25 CR [6.7%]) vs 29.3% (9 CR [2.4%]), with median DOR of 8.3 vs 6.0 mo. Approximately 20% vs 6% of pts had response duration ≥24 months. Grade 3-5 drug-related AE rates were 72% vs 68%. Discontinuation rates from drug-related AEs were 21% vs 12%. There was no significant difference in least square mean (LSM) change from baseline to wk 18 between arms in EORTC QLQ-C30 global health status/quality-of-life (LSM difference -0.10; 95% CI, -3.40-3.20). LSM change from baseline to wk 18 was better with pembro + chemo vs chemo for QLQ-OES 18 pain (-2.94; 95% CI, -5.86 to -0.02) and dysphagia (-5.54; 95% CI, -10.92 to -0.16). Conclusions: With an additional 12 months of follow-up, pembro + chemo continued to provide significant and clinically meaningful improvement in OS, PFS, and ORR vs chemo with a manageable safety profile, and stable quality-of-life for pts with untreated, advanced esophageal and EGJ cancer. These data continue to support 1L pembro + chemo as a new standard of care in these patients. Clinical trial information: NCT03189719.

First-line pembrolizumab + chemotherapy in Japanese patients with advanced/metastatic esophageal cancer from KEYNOTE-590

BACKGROUND

The phase 3 KEYNOTE-590 (NCT03189719) study showed first-line pembrolizumab plus chemotherapy significantly prolonged overall survival and progression-free survival versus placebo plus chemotherapy in patients with advanced unresectable or metastatic adenocarcinoma or squamous cell carcinoma of the esophagus or advanced/metastatic Siewert type I adenocarcinoma of the esophagogastric junction. We describe a subgroup analysis of Japanese patients from KEYNOTE-590.

METHODS

Eligible patients were randomly assigned 1:1 to pembrolizumab 200 mg intravenously every 3 weeks or placebo plus chemotherapy (cisplatin 80 mg/m² and 5-fluorouracil 800 mg/m²/day). Efficacy was evaluated in all Japanese patients and those with esophageal squamous cell carcinoma and programmed death ligand 1 combined positive score ≥ 10. Dual primary endpoints were overall survival and progression-free survival per RECIST v1.1 by investigator. Secondary endpoints included objective response rate per RECIST v1.1 by investigator and safety and tolerability.

RESULTS

At data cutoff (July 2, 2020), 141 Japanese patients were randomly assigned (pembrolizumab plus chemotherapy, 74; placebo plus chemotherapy, 67). In all Japanese patients, median overall survival was 17.6 months with pembrolizumab plus chemotherapy versus 11.7 months with chemotherapy (hazard ratio, 0.71; 95% confidence interval, 0.47-1.09), median progression-free survival was 6.3 versus 6.0 months (hazard ratio, 0.58; 95% confidence interval, 0.40-0.84), and objective response rate was 56.8% versus 38.8%. Grade 3-5 treatment-related adverse events were 74.3% and 61.2%.

CONCLUSION

First-line pembrolizumab plus chemotherapy demonstrated improvement in overall survival and progression-free survival compared with placebo plus chemotherapy in Japanese patients with advanced/metastatic esophageal cancer; safety was comparable between treatment groups.

CLINICAL TRIAL REGISTRY

ClinicalTrials.gov, NCT03189719.

A Phase I, Open-Label, Dose-Escalation Study of the OX40 Agonist Ivuxolimab in Patients with Locally Advanced or Metastatic Cancers

PURPOSE

Stimulation of effector T cells is an appealing immunotherapeutic approach in oncology. OX40 (CD134) is a costimulatory receptor expressed on activated CD4⁺ and CD8⁺ T cells. Induction of OX40 following antigen recognition results in enhanced T-cell activation, proliferation, and survival, and OX40 targeting shows therapeutic efficacy in preclinical studies. We report the monotherapy dose-escalation portion of a multicenter, phase I trial (NCT02315066) of ivuxolimab (PF-04518600), a fully human immunoglobulin G2 agonistic monoclonal antibody specific for human OX40.

PATIENTS AND METHODS

Adult patients (N = 52) with selected locally advanced or metastatic cancers received ivuxolimab 0.01 to 10 mg/kg. Primary endpoints were safety and tolerability. Secondary/exploratory endpoints included preliminary assessment of antitumor activity and biomarker analyses.

RESULTS

The most common all-causality adverse events were fatigue (46.2%), nausea (28.8%), and decreased appetite (25.0%). Of 31 treatment-related adverse events, 30 (96.8%) were grade ≤2. No dose-limiting toxicities occurred. Ivuxolimab exposure increased in a dose-proportionate manner from 0.3 to 10 mg/kg. Full peripheral blood target engagement occurred at ≥0.3 mg/kg. Three (5.8%) patients achieved a partial response, and disease control was achieved in 56% of patients. Increased CD4⁺ central memory T-cell proliferation and activation, and clonal expansion of CD4⁺ and CD8⁺ T cells in peripheral blood were observed at 0.1 to 3.0 mg/kg. Increased immune cell infiltrate and OX40 expression were evident in on-treatment tumor biopsies.

CONCLUSIONS

Ivuxolimab was generally well tolerated with on-target immune activation at clinically relevant doses, showed preliminary antitumor activity, and may serve as a partner for combination studies.

Efficacy and safety of trifluridine/tipiracil in older and younger patients with metastatic gastric or gastroesophageal junction cancer: subgroup analysis of a randomized phase 3 study (TAGS)

BACKGROUND

Trifluridine and tipiracil (FTD/TPI) demonstrated survival benefit vs placebo and manageable safety in previously treated patients with metastatic gastric/gastroesophageal junction cancer (mGC/GEJC) in the randomized, placebo-controlled, phase 3 TAGS study. This subgroup analysis of TAGS examined efficacy/safety outcomes by age.

METHODS

In TAGS, patients with mGC/GEJC and ≥ 2 prior therapies were randomized (2:1) to receive FTD/TPI 35 mg/m² or placebo, plus best supportive care. A preplanned subgroup analysis was performed to evaluate efficacy and safety outcomes in patients aged < 65, ≥ 65, and ≥ 75 years.

RESULTS

Among 507 randomized patients (n = 337 FTD/TPI; n = 170 placebo), 55%, 45%, and 14% were aged < 65, ≥ 65, and ≥ 75 years, respectively. Overall survival hazard ratios for FTD/TPI vs placebo were 0.67 (95% CI 0.51-0.89), 0.73 (95% CI 0.52-1.02), and 0.67 (95% CI 0.33-1.37) in patients aged < 65, ≥ 65, and ≥ 75 years, respectively. Regardless of age, patients receiving FTD/TPI experienced improved progression-free survival and stayed longer on treatment than those receiving placebo. Among FTD/TPI-treated patients, frequencies of any-cause grade ≥ 3 adverse events (AEs) were similar across age subgroups (80% each), although grade ≥ 3 neutropenia was more frequent in older patients [40% (≥ 65 and ≥ 75 years); 29% (< 65 years)]; AE-related discontinuation rates did not increase with age [14% (< 65 years), 12% (≥ 65 years), and 12% (≥ 75 years)].

CONCLUSIONS

The results of this subgroup analysis show the efficacy and tolerability of FTD/TPI treatment regardless of age in patients with mGC/GEJC who had received 2 or more prior treatments.

Second-line pembrolizumab versus chemotherapy in Japanese patients with advanced esophageal cancer: subgroup analysis from KEYNOTE-181

BACKGROUND

Safe and effective treatments for advanced esophageal cancer are an unmet need in Japan. We report results of a subgroup analysis of Japanese patients enrolled in KEYNOTE-181, a randomized, open-label, phase 3 study of pembrolizumab versus chemotherapy as second-line therapy for patients with advanced or metastatic esophageal cancer whose disease progressed after standard first-line therapy.

METHODS

Patients were randomly assigned 1:1 to receive pembrolizumab 200 mg every 3 weeks or investigator's choice of paclitaxel, docetaxel, or irinotecan. Efficacy was evaluated in all Japanese patients and in those with programmed death ligand 1 combined positive score ≥ 10.

RESULTS

Of the 152 Japanese patients enrolled (pembrolizumab, n = 77; chemotherapy, n = 75), 150 (98.7%) had squamous cell carcinoma and 79 (52.0%) had combined positive score ≥ 10. At the final analysis, median overall survival was improved among all patients (12.4 vs 8.2 months with pembrolizumab and chemotherapy, respectively; hazard ratio, 0.68; 95% CI 0.48-0.97) and patients with combined positive score ≥ 10 (12.6 vs 8.4 months; hazard ratio, 0.68; 95% CI 0.42-1.10). Fewer patients had any-grade (74.0% vs 95.9%) or grade 3-5 (16.9 vs 50.0%) treatment-related adverse events with pembrolizumab than with chemotherapy.

CONCLUSION

Consistent with the global trial results, second-line pembrolizumab therapy showed a survival benefit and a favorable safety profile compared with chemotherapy in Japanese patients with advanced esophageal cancer.

Pembrolizumab versus chemotherapy for patients with esophageal squamous cell carcinoma enrolled in the randomized KEYNOTE-181 trial in Asia

BACKGROUND

In the randomized phase III KEYNOTE-181 study, pembrolizumab prolonged overall survival (OS) compared with chemotherapy as second-line therapy in patients with advanced esophageal cancer and programmed death-ligand 1 (PD-L1) combined positive score (CPS) ≥10. We report a post hoc subgroup analysis of patients with esophageal squamous cell carcinoma (ESCC) enrolled in KEYNOTE-181 in Asia, including patients from the KEYNOTE-181 China extension study.

PATIENTS AND METHODS

Three hundred and forty Asian patients with advanced/metastatic ESCC were enrolled in KEYNOTE-181, including the China cohort. Patients were randomly assigned 1 : 1 to receive pembrolizumab 200 mg every 3 weeks for ≤2 years or investigator's choice of paclitaxel, docetaxel, or irinotecan. OS, progression-free survival, response, and safety were analyzed without formal comparisons. OS was evaluated based on PD-L1 CPS expression level.

RESULTS

In Asian patients with ESCC, median OS was 10.0 months with pembrolizumab and 6.5 months with chemotherapy [hazard ratio (HR), 0.63; 95% CI 0.50-0.80; nominal P < 0.0001]. Median progression-free survival was 2.3 months with pembrolizumab and 3.1 months with chemotherapy (HR, 0.79; 95% CI 0.63-0.99; nominal P = 0.020). Objective response rate was 17.1% with pembrolizumab and 7.1% with chemotherapy; median duration of response was 10.5 months and 7.7 months, respectively. In patients with PD-L1 CPS <1 tumors (pembrolizumab versus chemotherapy), the HR was 0.99 (95% CI 0.56-1.72); the HR (95% CI) for death was better for patients with PD-L1 CPS cut-offs >1 [CPS ≥1, 0.57 (0.44-0.75); CPS ≥5, 0.56 (0.41-0.76); CPS ≥10, 0.53 (0.37-0.75)]. Treatment-related adverse events were reported in 71.8% of patients in the pembrolizumab group and 89.8% in the chemotherapy group; grade 3-5 events were reported in 20.0% and 44.6%, respectively.

CONCLUSIONS

Pembrolizumab monotherapy demonstrated promising efficacy in Asian patients with ESCC, with fewer treatment-related adverse events than chemotherapy. PD-L1 CPS ≥1 is an appropriate cut-off and a predictive marker of pembrolizumab efficacy in Asian patients with ESCC.

Depletion of central memory CD8+ T cells might impede the antitumor therapeutic effect of Mogamulizumab

Regulatory T (Treg) cells are important negative regulators of immune homeostasis, but in cancers they tone down the anti-tumor immune response. They are distinguished by high expression levels of the chemokine receptor CCR4, hence their targeting by the anti-CCR4 monoclonal antibody mogamulizumab holds therapeutic promise. Here we show that despite a significant reduction in peripheral effector Treg cells, clinical responses are minimal in a cohort of patients with advanced CCR4-negative solid cancer in a phase Ib study (NCT01929486). Comprehensive immune-monitoring reveals that the abundance of CCR4-expressing central memory CD8+ T cells that are known to play roles in the antitumor immune response is reduced. In long survivors, characterised by lower CCR4 expression in their central memory CD8+ T cells possessed and/or NK cells with an exhausted phenotype, cell numbers are eventually maintained. Our study thus shows that mogamulizumab doses that are currently administered to patients in clinical studies may not differentiate between targeting effector Treg cells and central memory CD8+ T cells, and dosage refinement might be necessary to avoid depletion of effector components during immune therapy.