Convergent MAPK pathway alterations mediate acquired resistance to FGFR inhibitors in FGFR2 fusion-positive cholangiocarcinoma

BACKGROUND & AIMS

There is a knowledge gap in understanding mechanisms of resistance to fibroblast growth factor receptor (FGFR) inhibitors (FGFRi) and a need for novel therapeutic strategies to overcome it. We investigated mechanisms of acquired resistance to FGFRi in patients with FGFR2-fusion-positive cholangiocarcinoma (CCA).

METHODS

A retrospective analysis of patients who received FGFRi therapy and underwent tumor and/or cell-free DNA analysis, before and after treatment, was performed. Longitudinal circulating tumor DNA samples from a cohort of patients in the phase I trial of futibatinib (NCT02052778) were assessed. FGFR2-BICC1 fusion cell lines were developed and secondary acquired resistance mutations in the mitogen-activated protein kinase (MAPK) pathway were introduced to assess their effect on sensitivity to FGFRi in vitro.

RESULTS

On retrospective analysis of 17 patients with repeat sequencing following FGFRi treatment, new FGFR2 mutations were detected in 11 (64.7%) and new alterations in MAPK pathway genes in nine (52.9%) patients, with seven (41.2%) patients developing new alterations in both the FGFR2 and MAPK pathways. In serially collected plasma samples, a patient treated with an irreversible FGFRi tested positive for previously undetected BRAF V600E, NRAS Q61K, NRAS G12C, NRAS G13D and KRAS G12K mutations upon progression. Introduction of a FGFR2-BICC1 fusion into biliary tract cells in vitro sensitized the cells to FGFRi, while concomitant KRAS G12D or BRAF V600E conferred resistance. MEK inhibition was synergistic with FGFRi in vitro. In an in vivo animal model, the combination had antitumor activity in FGFR2 fusions but was not able to overcome KRAS-mediated FGFRi resistance.

CONCLUSIONS

These findings suggest convergent genomic evolution in the MAPK pathway may be a potential mechanism of acquired resistance to FGFRi.

CLINICAL TRIAL NUMBER

NCT02052778.

IMPACT AND IMPLICATIONS

We evaluated tumors and plasma from patients who previously received inhibitors of fibroblast growth factor receptor (FGFR), an important receptor that plays a role in cancer cell growth, especially in tumors with abnormalities in this gene, such as FGFR fusions, where the FGFR gene is fused to another gene, leading to activation of cancer cell growth. We found that patients treated with FGFR inhibitors may develop mutations in other genes such as KRAS, and this can confer resistance to FGFR inhibitors. These findings have several implications for patients with FGFR2 fusion-positive tumors and provide mechanistic insight into emerging MAPK pathway alterations which may serve as a therapeutic vulnerability in the setting of acquired resistance to FGFRi.

Preclinical Evaluation of the FGFR-Family Inhibitor Futibatinib for Pediatric Rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is the most common pediatric soft tissue sarcoma. Despite decades of clinical trials, the overall survival rate for patients with relapsed and metastatic disease remains below 30%, underscoring the need for novel treatments. FGFR4, a receptor tyrosine kinase that is overexpressed in RMS and mutationally activated in 10% of cases, is a promising target for treatment. Here, we show that futibatinib, an irreversible pan-FGFR inhibitor, inhibits the growth of RMS cell lines in vitro by inhibiting phosphorylation of FGFR4 and its downstream targets. Moreover, we provide evidence that the combination of futibatinib with currently used chemotherapies such as irinotecan and vincristine has a synergistic effect against RMS in vitro. However, in RMS xenograft models, futibatinib monotherapy and combination treatment have limited efficacy in delaying tumor growth and prolonging survival. Moreover, limited efficacy is only observed in a PAX3-FOXO1 fusion-negative (FN) RMS cell line with mutationally activated FGFR4, whereas little or no efficacy is observed in PAX3-FOXO1 fusion-positive (FP) RMS cell lines with FGFR4 overexpression. Alternative treatment modalities such as combining futibatinib with other kinase inhibitors or targeting FGFR4 with CAR T cells or antibody-drug conjugate may be more effective than the approaches tested in this study.

Discovery of Futibatinib: The First Covalent FGFR Kinase Inhibitor in Clinical Use

Deregulating fibroblast growth factor receptor (FGFR) signaling is a promising strategy for cancer therapy. Herein, we report the discovery of compound 5 (TAS-120, futibatinib), a potent and selective covalent inhibitor of FGFR1-4, starting from a unique dual inhibitor of mutant epidermal growth factor receptor and FGFR (compound 1). Compound 5 inhibited all four families of FGFRs in the single-digit nanomolar range and showed high selectivity for over 387 kinases. Binding site analysis revealed that compound 5 covalently bound to the cysteine 491 highly flexible glycine-rich loop region of the FGFR2 adenosine triphosphate pocket. Futibatinib is currently in Phase I-III trials for patients with oncogenically driven FGFR genomic aberrations. In September 2022, the U.S. Food & Drug Administration granted accelerated approval for futibatinib in the treatment of previously treated, unresectable, locally advanced, or metastatic intrahepatic cholangiocarcinoma harboring an FGFR2 gene fusion or other rearrangement.

Neighbourhood transportation, elapsed years, and well-being after surrendering the driver's licence in older Japanese adults: The JAGES longitudinal study

This study aimed to examine how the associations between surrendering driving licence and changes in self-rated health and social interactions among older adults differ by the years elapsed since surrendering and the number of public transportation systems (PTS) in the neighbourhood. We used the 2013 and 2016 survey data from the Japan Gerontological Evaluation Study targeting residents aged ≥65 years in 30 municipalities in Japan. Two-waves longitudinal data from 4894 older adults were evaluated. Based on the difference-in-differences method, the interaction terms of respondents' driving status, which was the categorical exposure variable representing respondents' driving status for three years during the study period, and a dummy variable of year (2016) were used as explanatory variables in logistic regression analyses to examine changes in outcomes (poor self-rated health and infrequent meeting with friends) between 2013 and 2016 by driving status during this period. Analyses were stratified based on neighbourhood PTS ('more PTS' and 'fewer PTS' groups). We found that, while surrendering licence within three years was associated with increased probability of poor self-rated health in more PTS group, the confidence interval was large. Although surrendering licence within three years was associated with decreased social interactions, this association weakened if licence was surrendered more than three years ago. These associations were not markedly affected by neighbourhood PTS. Our findings suggested that, regardless of neighbourhood PTS, support and care to promote social interactions at or shortly after surrendering licence may be beneficial to the well-being of older adults who lost their driving licence.

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.

[Differences in risk of requiring care between screening using queries with and without definitions when determining frequency of going out]

Objectives　This study elucidates the differences in risk for a functional decline in general housebound screening using queries with and without definitions.Methods　This study involved 10,802 community-dwelling older people who lived in four municipalities in Aichi Prefecture. The participants were asked about their frequency of going out in general and for five specific purposes: shopping, hospital visitation, strolling, leisure, and work. A person was defined as being "generally housebound" if he/she answered "less than once per week." However, a query with the definition of "going out" was used in only one of the four municipalities. Furthermore, we defined a person who goes out once a week, for any of the purposes, as "by-purpose non-housebound." If the response to the general and purpose-specific queries were inconsistent, we regarded it as an "inconsistent answer." Additionally, we compared the occurrence rate and hazard ratio for the onset of long-term care insurance certification of general housebound screening using queries with and without definition. We also calculated the occurrence rate and related risk factors for inconsistent answers.Results　The occurrence rate of general housebound screening using query with and without definition was 2.8% and 11.7%, respectively. Additionally, the hazard ratio for the onset of long-term care insurance certification of general housebound screening using the query with definition was 1.56 times more than that of general housebound screening using query without definition. The rate of inconsistent answers in by-purpose non-housebound using query with and without definition was 2.2% and 10.2%, respectively. However, sex, age, living with spouse and child(ren), years of schooling, self-rated health, depression, habitation in islands, and indicating definition of "going out" were related to inconsistent answers. The prevalence ratio of inconsistent answers in respondents using query with definition was significantly lower than among respondents using query without definition (PR=0.29).Conclusion　Query with definition reduced the occurrence rate of general housebound and increased the hazard ratio for the onset of long-term care insurance certification. Therefore, a definition should be added to queries asking for the frequency of going out to screen for housebound.

Abstract 2618: Convergent MAPK pathway alterations mediate acquired resistance to FGFR inhibitors in cholangiocarcinoma with FGFR fusions/rearrangements

Purpose: Genomic aberrations in fibroblast growth factor receptor (FGFR) are oncogenic drivers in several cancers. FGFR inhibitors (FGFRi) have demonstrated antitumor activity in cholangiocarcinoma (CCA) with FGFR2 fusions/rearrangements, though acquired resistance remains a therapeutic challenge and has been linked to FGFR2 mutations other than fusions/rearrangements. We sought to investigate mechanisms of acquired resistance to FGFRi and approaches to overcome resistance.

Methods: Longitudinal plasma samples were collected from patients with FGFR pathway alterations enrolled in the futibatinib phase I trial (NCT02052778) and sequenced using a targeted, 73-gene panel. A separate retrospective analysis was conducted to evaluate possible evolution of genomic aberrations in CCA patients with FGFR2 fusion/rearrangement who had additional tumor and/or plasma next-generation sequencing (NGS) following FGFRi therapy. To assess the efficacy of futibatinib in cells with FGFR2 fusions in vitro, a FGFR2-BICC1 fusion H69 cholangiocyte cell line was developed. MAPK pathway alterations (BRAF_V600E or KRAS_G12D) were introduced to determine the impact of these co-alterations on FGFRi sensitivity, and combinations were tested to determine if efficacy could be enhanced. Cell viability assays, colony formation assays, and western blots were utilized to determine the effects of these agents in engineered cells.

Results: A total of 58 plasma samples were collected from 17 patients with FGFR pathway alterations who were enrolled in the futibatinib phase I trial, including 13 (76.5%) of which had CCA. One patient with a FGFR2-CTNNA3 fusion who had NRAS G12D and BRAF A694T at baseline which were undetected during treatment had a dramatic increase in their variant allele frequency (VAF) upon progression (4.2%-0.0%-100% and 2.8%-0.0%-50.9%, respectively). Further, additional MAPK alterations were detected at time of progression, including BRAF V600E, NRAS Q61K, NRAS G12C, NRAS G13D and KRAS G12K mutations. In our separate retrospective series, of 17 patients who underwent repeat tumor and/or plasma NGS following treatment with one or more FGFRi, 10 (58.8%) had newly detectable alterations in MAPK pathway genes, 10 (58.8%) had new FGFR2 alterations, and 7 (41.2%) developed new alterations in both FGFR2 and MAPK pathway genes. In vitro studies demonstrated that in isogenic H69 biliary cell lines, introduction of FGFR2-BICC1 robustly sensitized to FGFRi when compared to a parental cell line, which was blunted by the introduction of secondary KRAS_G12D or BRAF_V600E mutations.

Conclusions: Convergent genomic evolution in the MAPK pathway may be a potential mechanism of acquired resistance to FGFRi therapy. Work is ongoing to determine if targeting co-alterations may enhance the efficacy of FGFRi in FGFR2-fusion driven malignancies.

Citation Format: TImothy P. DiPeri, Ming Zhao, Tyler Moss, Michael Kahle, Payal Rauli, Sunyoung S. Lee, Abdel Halim, Hiroshi Hirai, Volker Wacheck, Karim Benhadji, Jordi Rodon, Milind Javle, Funda Meric-Bernstam. Convergent MAPK pathway alterations mediate acquired resistance to FGFR inhibitors in cholangiocarcinoma with FGFR fusions/rearrangements [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 2618.

Abstract 1117: Acquired resistance to ATP-competitive and irreversible FGFR inhibitors (FGFRi's): A library-based approach

Background: The emergence of secondary FGFR kinase domain (KD) mutations with FGFRi's leads to drug resistance and disease progression. The frequency of resistance mutations with individual FGFRi's is unknown. Using an unbiased library-based approach, we examined the development of acquired resistance with the irreversible FGFRi futibatinib and the ATP-competitive FGFRi's erdafitinib (ERD) and pemigatinib (PEM).

Methods: Mutant (mt) libraries were generated with random mutagenesis in two FGFR2 KD regions: #1 (amino acids [aa] 540-569), and #2 (aa 640-669). Library were transfected as TEL-fusions into Ba/F3 cells, resulting in FGFR2-dependent cell growth. Transfected cells were treated with FGFRi's at concentrations suppressing parental cell line growth. Surviving drug-resistant clones were counted, isolated, and sequenced to identify the KD mutation. The inhibitory activity of FGFRi's against resistant clones was assessed using phospho-FGFR2 ELISA.

Results: Treatment of the library-transfected Ba/F3-TEL-FGFR2 KD cells with PEM, ERD, and futibatinib resulted in an average (n=2) of 93, 27, and 13 resistant clones in region #1 and 28, 21 and 1 resistant in region #2, respectively. Sequencing (table) identified, among others, the following aa mutations: N549, E565, and K641 (regulatory triad), V564 (gatekeeper region) and K659 (activation loop), also seen in patients who developed resistance to Debio1347, infigratinib, and PEM. Among FGFR mts shown (table), futibatinib inhibited 8/10, and ERD, 5/10 mts at IC50 values comparable to wild type (wt) FGFR; however, PEM activity against all FGFR mts was attenuated by ≥5-fold vs wt.

Conclusions: Resistance mutations identified with this unbiased library-based in vitro approach were consistent with those observed in the clinic. Acquired drug resistance mutations were less frequent with futibatinib than with ATP-competitive FGFRi's. Futibatinib demonstrated the most robust inhibition of drug resistant mts.

FGFR mutationKD regionFutibatinib IC50 (nM)Erdafitinib IC50 (nM)Pemigatinib IC50 (nM)Wild-type (parent)-2.12.51.5N549DRegulatory triad4.225.5153.2N549KRegulatory triad16.732.0246.2V562L-6.32.97.7V564IGatekeeper8.32.762.4V564LGatekeeper91.956.5502.3E565ARegulatory triad6.82.911.8E565GRegulatory triad3.93.09.0K641IRegulatory triad3.855.829.6K641RRegulatory triad4.73.210.3K659MActivation loop9.546.633.8

Citation Format: Hiroshi Sootome, Suzuko Kato, Masanori Kato, Hiroshi Hirai. Acquired resistance to ATP-competitive and irreversible FGFR inhibitors (FGFRi's): A library-based approach [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1117.

TAS-119, a novel selective Aurora A and TRK inhibitor, exhibits antitumor efficacy in preclinical models with deregulated activation of the Myc, β-Catenin, and TRK pathways

Aurora kinase A, a mitotic kinase that is overexpressed in various cancers, is a promising cancer drug target. Here, we performed preclinical characterization of TAS-119, a novel, orally active, and highly selective inhibitor of Aurora A. TAS-119 showed strong inhibitory effect against Aurora A, with an IC50 value of 1.04 nmol/L. The compound was highly selective for Aurora A compared with 301 other protein kinases, including Aurora kinase B. TAS-119 induced the inhibition of Aurora A and accumulation of mitotic cells in vitro and in vivo. It suppressed the growth of various cancer cell lines harboring MYC family amplification and CTNNB1 mutation in vitro. In a xenograft model of human lung cancer cells harboring MYC amplification and CTNNB1 mutation, TAS-119 showed a strong antitumor activity at well-tolerated doses. TAS-119 induced N-Myc degradation and inhibited downstream transcriptional targets in MYCN-amplified neuroblastoma cell lines. It also demonstrated inhibitory effect against tropomyosin receptor kinase (TRK)A, TRKB, and TRKC, with an IC50 value of 1.46, 1.53, and 1.47 nmol/L, respectively. TAS-119 inhibited TRK-fusion protein activity and exhibited robust growth inhibition of tumor cells via a deregulated TRK pathway in vitro and in vivo. Our study indicates the potential of TAS-119 as an anticancer drug, especially for patients harboring MYC amplification, CTNNB1 mutation, and NTRK fusion.

Abstract 564: Futibatinib (TAS-120) plus chemotherapy demonstrates a synergistic effect across various FGFR-deregulated cancer cell lines and xenograft models

Introduction: Futibatinib, a selective, irreversible fibroblast growth factor receptor (FGFR) 1-4 inhibitor, has antitumor activity in FGFR-deregulated cancer models. The potential synergistic antitumor effects of targeted therapy plus chemotherapy (chemo) was evaluated by combining futibatinib with cytotoxic agents in in vitro and in vivo models.

Methods: Gastric, breast, lung, endometrial, and bladder cancer cell lines with various FGFR aberrations were treated with futibatinib and cytotoxic agents (5-FU, paclitaxel, cisplatin, or gemcitabine) individually or in combination. In vitro cytotoxicity of futibatinib was assessed by PARP cleavage activity. Any combination effect on cell growth was determined by the Bliss independence method, combination index (CI; CalcuSyn software), or isobologram analysis. The antitumor effects of futibatinib plus S-1 or paclitaxel and futibatinib plus gemcitabine or cisplatin were evaluated in gastric FGFR2-amplified SNU-16 and endometrial FGFR2-N549K-mutated AN3CA mouse xenograft models, respectively, by measuring relative tumor volume (RTV).

Results: A synergistic effect on cell growth inhibition was observed with futibatinib plus chemo in SNU-16 cells (CIs at ED90 were 0.50 [5-FU], 0.71 [paclitaxel], 0.76 [cisplatin], and 0.29 [gemcitabine]). Increased PARP cleavage and decreased cell growth were observed in SNU-16 cells treated with futibatinib plus 5-FU vs monotherapy. Synergized cell growth inhibition occurred in various FGFR-deregulated cancer cell lines. In xenograft models, vs monotherapy, a significant reduction (P&lt;0.01) in RTV occurred with futibatinib plus S-1, paclitaxel (Table), or cisplatin and a numerically greater reduction with futibatinib plus gemcitabine.

Table.Relative tumor volume in SNU-16 mouse xenografts treated with futibatinib or paclitaxel or combination therapyTreatment (mg/kg/d)Relative tumor volumeDay 0Day 4Day 8Day 11Day 15Control11.562.373.344.58Futibatinib (5)a11.321.952.773.83Futibatinib (15)a11.211.822.453.16Paclitaxel (60)b10.480.410.410.59Futibatinib + paclitaxel (5 + 60)c10.470.270.170.14Futibatinib + paclitaxel (15 + 60)c10.440.220.120.07aDays 1-14 (oral).bDay 1 (intravenous).cDays 1-14 + Day 1.

Conclusions: Futibatinib showed a synergistic antitumor effect in vitro and in vivo when combined with various cytotoxic agents. These data are promising and warrant further investigation.

Citation Format: Hiroshi Sootome, Akihiro Miura, Toshiharu Komori, Hiroshi Hirai. Futibatinib (TAS-120) plus chemotherapy demonstrates a synergistic effect across various FGFR-deregulated cancer cell lines and xenograft models [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 564.

Abstract 661: Synergistic antitumor activity of futibatinib, an FGFR1-4 inhibitor, and TAS-117, a selective AKT inhibitor, in FGFR-deregulated cancer models

Background: TAS-117 is a potent oral allosteric non-ATP inhibitor selective for AKT. A phase 1 study with TAS-117 is ongoing in patients with endometrial cancer and ovarian clear cell carcinoma. Futibatinib (TAS-120) is a selective, irreversible small-molecule fibroblast growth factor receptor (FGFR) 1-4 inhibitor, with potent antiproliferative activity in preclinical models with FGFR aberrations. Phase 2 studies are ongoing in patients with various FGFR-deregulated cancers. We evaluated the antitumor activity of futibatinib plus TAS-117 in FGFR-aberrant cancer models.

Methods: Effects of futibatinib plus TAS-117 were investigated in human endometrial FGFR2-N549K-mutated AN3CA cancer cells and small-cell lung cancer FGFR1-amplified DMS114 cells. Activation of RAS and PI3K pathways was assessed by detecting phosphorylation of ERK1/2, AKT, and S6. Antitumor combination indices (CI) for cell viability over time were determined with the Chou-Talalay median-effect method and CalcuSyn software; a CI&lt;0.9 indicates synergy. Antitumor effects of futibatinib (15 mg/kg/d) plus TAS-117 (4 or 8 mg/kg/d) or monotherapy were also evaluated in a mouse AN3CA xenograft model. FGFR signaling, apoptosis (via caspase activity and PARP cleavage), and relative tumor volume (RTV; compared with Day 0) were assessed.

Results: Futibatinib and TAS-117 synergistically increased cell death and decreased cell growth in AN3CA (CI&lt;0.40) and DMS114 (CI&lt;0.40) cells, respectively. Apoptosis induction was readily detected with futibatinib plus TAS-117 in AN3CA cells, but low activity was observed with monotherapy. In both AN3CA and DMS114 cells, futibatinib suppressed ERK1/2, but not AKT phosphorylation; the futibatinib plus TAS-117 combination suppressed phosphorylation of both ERK1/2 and AKT. In AN3CA xenografts, combination therapy inhibited the FGFR, PI3K, and MEK pathways. Futibatinib plus TAS-117 increased PARP cleavage more than monotherapy. Compared with Day 0, RTV on Day 15 was 60.71 in the control, 13.40 with futibatinib monotherapy, and 33.63 with TAS-117 (8 mg/kg/d) monotherapy. Treatment with 3 different futibatinib plus TAS-117 combination dosing regimens resulted in marked reductions in RTVs on Day 15 (2.16, 0.53, and 0.22).

Conclusions: Our findings suggest that futibatinib plus TAS-117 has synergistic antitumor effects in FGFR-aberrant tumors. A phase 1/2 study of this combination in advanced solid tumors (JapicCTI-194864) is ongoing.

Citation Format: Junya Iwasaki, Takuya Kuramoto, Toshiharu Komori, Hitoshi Saito, Hiroshi Hirai. Synergistic antitumor activity of futibatinib, an FGFR1-4 inhibitor, and TAS-117, a selective AKT inhibitor, in FGFR-deregulated cancer models [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 661.

Aurora A Inhibitor TAS-119 Enhances Antitumor Efficacy of Taxanes In Vitro and In Vivo: Preclinical Studies as Guidance for Clinical Development and Trial Design

TAS-119 is a novel orally active, selective inhibitor of Aurora kinase A identified as a clinical candidate for efficacy testing in combination with taxanes. In vitro, TAS-119 enhanced cell growth inhibition of paclitaxel in multiple human cancer cell lines derived from various tissues, including paclitaxel-resistant cell lines. Interestingly, TAS-119 did not enhance paclitaxel antitumor activity in normal lung diploid fibroblast cell lines WI-38 and MRC5. In vivo, TAS-119 enhanced the antitumor efficacy of paclitaxel and docetaxel in multiple models at doses inhibitory to Aurora A in tumors. Moreover, the drug combination was well tolerated, and TAS-119 did not exaggerate clinically documented side effects of taxanes, neutropenia and neurotoxicity, in rats. The same TAS-119 concentration enhanced the cell growth inhibitory activity of three clinically approved taxanes, paclitaxel, docetaxel, and cabazitaxel. The degree of enhancement calculated as fold of change of the IC₅₀ value for each taxane was almost the same among the three taxanes. We conducted in vitro and in vivo experiments to develop an optimized combination therapy regimen for TAS-119 with paclitaxel/docetaxel. Using in vitro and in vivo models, we tested the drug administration order for TAS-119 combined with paclitaxel and the TAS-119 treatment duration. The best regimen in preclinical models was combining paclitaxel or docetaxel treatment with 4 days of TAS-119 dosing, which was initiated on the same day as the paclitaxel or docetaxel administration or one day later. This information provided guidance for the design of a clinical trial of TAS-119 and paclitaxel or docetaxel combination.

The Risk of Functional Limitations After Driving Cessation Among Older Japanese Adults: The JAGES Cohort Study

Background

Population ageing and stringent licensing policies will increase the number of older drivers who stop driving. Adverse health outcomes owing to driving cessation and their prevention are emerging concerns. Therefore, we longitudinally examined the impact of driving cessation and alternative transportation use after cessation on the risk of functional limitations in a cohort of community-dwelling people (65 years and older) in Japan.

Methods

Using cohort data of those who drove as of 2006/07, we compared the risk of functional limitations between 2,704 current drivers and 140 former drivers (who stopped driving by 2010). Of the former drivers, 77 did not use public transportation or bicycles after driving cessation (thus losing independent mobility). We calculated the hazard ratios (HRs) for the incidence of functional limitations with 95% confidence intervals (CIs) based on the Cox proportional hazards model with the covariates influencing the functional limitations.

Results

From 2010 through 2016, 645 people had functional limitations, which included 38, 82, and 119 per 1,000 person-years among current drivers, former drivers who used public transportation or bicycles, and former drivers who were only driven by others, respectively (HR 1.69; 95% CI, 1.15–2.49 and HR 2.16; 95% CI, 1.51–3.10, relative to current drivers).

Conclusion

Driving cessation is associated with an increased risk of functional limitations among older adults, but this risk might be alleviated if they are able to maintain independent mobility using public transportation or bicycles after driving cessation.

TAS-120 Overcomes Resistance to ATP-Competitive FGFR Inhibitors in Patients with FGFR2 Fusion-Positive Intrahepatic Cholangiocarcinoma

ATP-competitive fibroblast growth factor receptor (FGFR) kinase inhibitors, including BGJ398 and Debio 1347, show antitumor activity in patients with intrahepatic cholangiocarcinoma (ICC) harboring activating FGFR2 gene fusions. Unfortunately, acquired resistance develops and is often associated with the emergence of secondary FGFR2 kinase domain mutations. Here, we report that the irreversible pan-FGFR inhibitor TAS-120 demonstrated efficacy in 4 patients with FGFR2 fusion-positive ICC who developed resistance to BGJ398 or Debio 1347. Examination of serial biopsies, circulating tumor DNA (ctDNA), and patient-derived ICC cells revealed that TAS-120 was active against multiple FGFR2 mutations conferring resistance to BGJ398 or Debio 1347. Functional assessment and modeling the clonal outgrowth of individual resistance mutations from polyclonal cell pools mirrored the resistance profiles observed clinically for each inhibitor. Our findings suggest that strategic sequencing of FGFR inhibitors, guided by serial biopsy and ctDNA analysis, may prolong the duration of benefit from FGFR inhibition in patients with FGFR2 fusion-positive ICC. SIGNIFICANCE: ATP-competitive FGFR inhibitors (BGJ398, Debio 1347) show efficacy in FGFR2-altered ICC; however, acquired FGFR2 kinase domain mutations cause drug resistance and tumor progression. We demonstrate that the irreversible FGFR inhibitor TAS-120 provides clinical benefit in patients with resistance to BGJ398 or Debio 1347 and overcomes several FGFR2 mutations in ICC models.This article is highlighted in the In This Issue feature, p. 983.

First-in-human phase I and pharmacological study of TAS-119, a selective Aurora A (AurA) kinase inhibitor, in patients (pts) with advanced solid tumors

3063

Background: AurA is a serine threonine kinase regulating cell division and cell cycle progression and has a role in carcinogenesis. This clinical trial investigated safety, pharmacokinetics and -dynamics and antitumor activity of the selective oral AurA kinase inhibitor TAS-119. Methods: Pts with advanced solid tumors were enrolled into 6 dose escalation cohorts (70-300 mg BID 4 days on/3 days off; every 3 out of 4 weeks; or the same schedule in a continuous weekly schedule). In the expansion phase (intermittent schedule), pts with small-cell lung cancer (SCLC), breast cancer, or MYC-amplified/B-catenin mutated (MT) tumors were enrolled, and pts with other solid tumors in a basket cohort. Results: Overall, 34 pts were enrolled to the escalation (median age 67 years; 45.3% > 2 prior therapies); DLT was observed in 5 (16.1%) of 31 DLT evaluable pts; 1/10 at 150 mg, 1/6 at 200 mg, 1/5 at 250 mg, and 2/2 at 300 mg BID (fatigue, nausea, dry eyes, corneal epithelial microcysts). The maximum tolerated dose (MTD) was 250 mg BID and recommended Phase 2 dose (RP2D) was 200 mg BID. The most frequent treatment-emergent adverse events were diarrhea (28.3%), eye disorders (27%), fatigue (22.9%), and decreased appetite (14.8%). Grade 3 ocular toxicity were corneal epithelial microcysts in 1 pt (300 mg cohort) and punctate keratitis (expansion breast cancer cohort) in 1 pt. Toxicity grade ≥ 3 in ≥ 10% of pts were diarrhea (escalation part only), and increased lipase. Plasma exposure was dose-proportional and accumulation ratio was low. Pharmacodynamic data demonstrated target inhibition. Overall, 40 pts were enrolled to multiple expansions (10 SCLC, 9 breast cancer, 13 MYC-amp/B-cat MT tumors, 8 other; median age 60 years; 72.5% > 2 prior therapies). Median delivered relative dose intensity was 89.1% (47.9% - 100%). Stable disease was reported in 37.8% of patients but no complete or partial responses. Conclusions: TAS-119 demonstrated favorable safety and tolerability. Low-grade eye toxicity was a dose-dependent toxicity. Preliminary anti-tumor activity of monotherapy TAS-119 is limited. A Phase 1 trial combining TAS-119 with paclitaxel was conducted in parallel. Clinical trial information: NCT02448589.

Phase I study of the Aurora A kinase (AurA) inhibitor TAS-119 with paclitaxel (P) in advanced solid tumors

3031

Background: AurA is a key regulator of cell division, including mitotic spindle assembly. However, elevated levels of AurA have been reported to abrogate the mitotic spindle checkpoint activated by taxanes leading to treatment resistance. Preclinical studies of TAS-119 + P showed enhanced antitumor activity and suggested an optimal timing window of the combination. Study objective was to assess the safety of TAS-119 + P in adult patients (pts) with advanced solid tumors. Methods: Dose escalation used a 3+3 design to determine the maximum tolerated dose (MTD); 7 dose levels (DLs) were explored, starting with 25 mg TAS-119 BID dosed 4 days/week (d/wk) and weekly 90 mg/m2 P for 3 weeks of a 4 week cycle (DL1). Plasma samples were collected during cycle 1 to evaluate pharmacokinetics. In expansion, pts with advanced breast/ovarian cancers were treated at the MTD. Results: Dose escalation enrolled 26 pts with various cancers, the majority being pancreas, colon, and ovarian; 2 pts were not evaluable for DLT assessment and replaced. A DLT (neutropenia and elevated AST) was observed in 2/3 pts in DL1. Dosing was modified to 25 mg TAS-119 BID 2 d/wk and P 70 mg/m2 (DL2) and no DLTs were observed. Zero DLTs were observed in the next 4 doses: 70 mg/m2 P + TAS-119 2 d/wk at 50 mg BID (DL3) or 75 mg BID (DL4), or 80 mg/m2 P + TAS-119 at 75 mg BID 2 d/wk (DL5) or 75 mg BID 3 d/wk (DL6). TAS-119 was escalated to 100 mg BID 3 d/wk (DL7) and 3 DLTs (n=1, elevated ALT; n=1, diarrhea and mucositis) occurred in 2/3 pts. Three additional pts were then enrolled at DL6 to confirm the MTD. One breast and 2 ovarian pts were enrolled in expansion before the trial was suspended by the company. Toxicities observed in ≥30% of pts were diarrhea, nausea, and fatigue (most ≤Gr2). Plasma TAS-119 exposure increased dose-proportionally in 2 d/wk and 3 d/wk schedules; no impact of TAS-119 on PK of paclitaxel was found. The disease control rate was 59% (17/29); 4 of these pts had a partial response. Conclusions: The combination had a manageable toxicity profile at the MTD of 80 mg/m2 P + TAS-119 at 75 mg BID 3 d/wk. Preliminary clinical activity was seen in 59% of pts, including tumor responses in a majority (4/7) of pts with ovarian/fallopian tube cancers. Clinical trial information: NCT02134067.

A prospective phase II study of combined androgen blockade in patients with androgen receptor-positive metastatic or locally advanced unresectable salivary gland carcinoma

Background

There is no standard first-line chemotherapy for recurrent/metastatic (RM) or unresectable locally advanced (LA) salivary gland carcinoma (SGC).

Patients and methods

We conducted a single institution, open-label, single arm, phase II trial of combined androgen blockade (CAB) for androgen receptor (AR)-positive SGC. Leuprorelin acetate was administered subcutaneously at a dose of 3.75 mg every 4 weeks. Bicalutamide was administered orally at a daily dose of 80 mg. Patients were treated until progressive disease or unacceptable toxicities.

Results

Thirty-six eligible patients were enrolled. Thirty-three patients had RM disease and three patients had LA disease. The pathological diagnoses were salivary duct carcinoma (34 patients, 94%) and adenocarcinoma, NOS (two patients, 6%). The best overall response rate was 41.7% [n = 15, 95% confidence interval (CI), 25.5%-59.2%], the clinical benefit rate was 75.0% (n = 27, 95% CI, 57.8%-87.9%). The median progression-free survival was 8.8 months (95% CI, 6.3-12.3 months) and the median overall survival was 30.5 months (95% CI, 16.8 months to not reached). Additional analyses between treatment outcomes and clinicopathological factors or biomarkers including AR positivity, human epidermal growth factor receptor 2 status, and its complex downstream signaling pathway gene mutations showed no statistically significant differences. Elevated grade 3 liver transaminases and increased serum creatinine were reported in two patients, respectively. Discontinuation of leuprorelin acetate or bicalutamide due to adverse event occurred in one patient.

Conclusion

This study suggests that CAB has equivalent efficacy and less toxicity for patients with AR-positive RM or unresectable LA SGC compared with conventional chemotherapy, which warrants further study.

Clinical Trial Registration

UMIN-CTR (http://www.umin.ac.jp/ctr/index-j.htm), identification number: UMIN000005703.

Artificial Conditioner for Stored Organs

We have developed an artificial organ conditioning system in order not only to condition but also evaluate the viability for transplant graft of kidneys which have been stored for a long time and damaged by warm ischaemia following cardiac arrest. The conditioning system consisted of an artificial lung, a roller pump, an organ chamber and perfusate. The perfusate was prepared with electrolytes, fluorocarbon, amino acid, glucose, an oxygen scavenger and so on. Conditioning was performed by continuous perfusion under mild hypothermia at 24° C. Mildly damaged kidneys (0 and 30 minutes warm ischaemia rabbit kidneys) were well conditioned but severely damaged kidneys failed to produce urination. Our device successfully exposed the viability of stored kidneys and the successful conditioning of damaged kidneys due to warm ischaemia avoiding transplantation. By establishing our method, the harvesting of kidneys following cardiac arrest will be feasible.

Constitutively active ABL family kinases, TEL/ABL and TEL/ARG, harbor distinct leukemogenic activities in vivo

ABL (ABL1) and ARG (ABL2) are highly homologous to each other in overall domain structure and amino-acid sequence, with the exception of their C termini. As with ABL, translocations that fuse ARG to ETV6/TEL have been identified in patients with leukemia. To assess the in vivo leukemogenic activity of constitutively active ABL and ARG, we generated a bone marrow (BM) transplantation model using the chimeric forms TEL/ABL and TEL/ARG, which have comparable kinase activities. TEL/ABL rapidly induced fatal myeloid leukemia in recipient mice, whereas recipients of TEL/ARG-transduced cells did not develop myeloid leukemia, instead, they succumbed to a long-latency infiltrative mastocytosis that could be adoptively transferred to secondary recipients. Swapping of the C termini of ABL and ARG altered disease latency and phenotypes. In a detailed in vitro study, TEL/ARG strongly promoted mast cell differentiation in response to stem cell factor or interleukin-3, whereas TEL/ABL preferentially induced myeloid differentiation of hematopoietic stem/progenitor cells. These results indicate that ABL and ARG kinase activate distinct differentiation pathways to induce specific diseases in vivo, that is, myeloid leukemia and mastocytosis, respectively. Further elucidation of the differences in their properties should provide important insight into the pathogenic mechanisms of oncogenes of the ABL kinase family.

[Criteria for social isolation based on associations with health indicators among older people. A 10-year follow-up of the Aichi Gerontological Evaluation Study]

OBJECTIVES

No clear evidence for a cut-off point for social isolation has been established so far. The purpose of this study was to evaluate the criteria for social isolation based on associations with objective health outcomes in a 10-year follow-up study.

METHODS

We performed a prospective study of functionally independent residents aged 65 years or older who lived in six municipalities as part of the Aichi Gerontological Evaluation Study (response rate: 50.4%) that began in 2003. Data on the onset of functional disability, dementia, and death were obtained from municipal databases of the public long-term care insurance system. A total of 12,085 participants were followed up for up to 10 years. We used frequencies of face-to-face and non-face-to-face contact with non-resident children, relatives and friends, or neighbors as indicators of social isolation. The overall frequency of contact with others was categorized from "less than once a month" to "frequently, every day."

RESULTS

Cox's proportional hazard model revealed that, after controlling for sex, age, education level, marital status, equivalent household income, need for medical care, self-recognition of forgetfulness, and residential area, the hazard ratios for functional disability (over long-term care level 2), dementia, and premature death increase in those with contact frequency of "less than once a month" were 1.37 (95% confidence interval [CI]: 1.16-1.61), 1.45 (95% CI: 1.21-1.74), and 1.34 (95% CI: 1.16-1.55), respectively. The "from once a month to once a week" frequency was also associated with these health indicators, although the "more than once a week" frequency was not significantly associated with any measured outcome. The prevalence of "less than once a month" contact was 7.4% (men=10.2%, women=4.7%), and this was 15.8% (men=21.2%, women=10.6%) when including those with "less than once a week" contact.

CONCLUSION

These findings suggest that "less than once a week" or "less than once a month" contact with non-cohabitant others are valid operational definitions of social isolation that are closely associated with premature death and other health indicators.

Evaluating Chemical CDK Inhibitors as Cell Death Inducers

The cell cycle of eukaryotic cells is regulated by a family of protein kinases called cyclin-dependent kinases (Cdks). We have reported the identification and biological characterization of a highly potent, small-molecule pan-Cdk inhibitor, which inhibited Cdk1, 2, 4, 5, 6, and 9 with equal potency in the nM range. This compound inhibited multiple events in the cell cycle and induced cell death in human cancer cell lines as well as in peripheral blood or purified resting lymphocytes ex vivo. We describe the materials and methods to determine antitumor efficacy in vivo xenograft models. Pharmacodynamic marker assays that have been performed using tumors and normal tissues are explained. Moreover, we briefly describe methods for determining the effects of chemical Cdk inhibitors on peripheral blood cells or lymphocytes ex vivo.

Abstract C187: Cross-inhibition of Trk receptors by TAS-119, a novel Aurora A selective inhibitor, exhibits therapeutic potential in a Trk-driven cancer model

Background; Comprehensive analysis by next-generation sequencing has identified oncogenic gene rearrangement of Trk neurotrophin receptors TrkA, TrkB and TrkC (encoded by NTRK1, NTRK2, and NTRK3 gene, respectively) in multiple tumor types including lung adenocarcinoma, colorectal cancer, glioblastoma and acute myeloid leukemia. The creation of gene fusion through genomic rearrangement results in constitutive activation of the kinase domain of Trk. These recent findings encourage study of the therapeutic potential of Trk kinases as drug targets for the specific treatment of patients with oncogenic NTRK gene abnormalities. TAS-119 is a novel small molecular weight inhibitor of Aurora A kinase and currently investigated in phase 1 clinical trial as both an enhancer of microtubule stabilizing drugs and monotherapy (1-3). In addition, TAS-119 shows pan-Trk inhibition with potency similar to Aurora A inhibition. Here, we describe the in vitro and in vivo pharmacologic profile of TAS-119 as a pan-Trk inhibitor.

Methods; Kinase assays were performed with purified recombinant enzymes under optimized conditions using ATP concentration at or just below the respective Km. In cell proliferation studies, cell viability was determined at 72 hour by detecting cellular ATP concentration. Analysis of protein expression including phosphorylated proteins was conducted by Western blotting. In tumor xenograft models, cells were implanted subcutaneously in nude mice. TAS-119 was administered orally with twice daily or intermittent dosing (4 days on/ 3 days off schedule) for 14 days.

Results; TAS-119 inhibited TrkA activity with an IC50 of 1 nM in cell-free system, and inhibited TrkA autophosphorylation and cell proliferation of KM12C colorectal cancer cell line harbouring TPM3-TrkA fusions at sub-nM range. In the KM12C xenograft model, both continuous and intermittent treatment with TAS-119 at 60 mg/kg or 100 mg/kg b.i.d. for 14 days resulted in dose-dependent inhibition of tumor growth with good tolerability. Delays of tumor growth in xenograft model were well correlated with reduction of TrkA autophosphorylation and inhibition of downstream signal transduction like pPLCγ, pERK and pAKT within tumors.

Conclusions; TAS-119 is an orally bioavailable dual-specificity kinase inhibitor developed specifically for both Trk and Aurora A inhibition with favorable profiles in animals. These preclinical data suggest that TAS-119 has therapeutic potential for cancers with Trk rearrangements. Currently, phase 1 dose-escalation clinical trial is ongoing. Although TAS-119 is primarily being developed as an inhibitor for Aurora A kinase, it should also be tested clinically in patients with tumors showing Trk gene rearrangement.

1) 24th EORTC-NCI-AACR Symposium (2012), abstract #251 and #252

2) 25th EORTC-NCI-AACR Symposium (2013), abstract #A268 and #A269

3) 26th EORTC-NCI-AACR Symposium (2014), abstract #P005 and #P178

Citation Format: Hiroshi Sootome, Akihiro Miura, Kimihiro Ito, Takamasa Suzuki, Hiroshi Hirai, Teruhiro Utsugi, Kazuhiko Yonekura. Cross-inhibition of Trk receptors by TAS-119, a novel Aurora A selective inhibitor, exhibits therapeutic potential in a Trk-driven cancer model. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr C187.

Influence of socioeconomic status on the association between body mass index and cause-specific mortality among older Japanese adults: The AGES Cohort Study

OBJECTIVE

Many studies have suggested a U-shaped curve for the association between body size and mortality risks, i.e., mortality risks increase in those who are both overweight and underweight. The strength of the associations may vary according to socioeconomic statuses (SES), as they determine levels of access to healthcare and psychosocial stresses. We investigated the modifying effects of SES on the relationship between body mass index (BMI) and mortality.

METHOD

We used prospective cohort data of participants in the Aichi Gerontological Evaluation Study in 2003 (n=14,931), who were 65years or older and physically and cognitively independent at baseline, and residing in eight municipalities in Japan. Data on all-causes mortality and mortality from cancer, cardiovascular disease, and respiratory disease was obtained from municipal government registries.

RESULTS

Proportional hazard regression analyses showed that, among men, the associations between overweight (BMI≥25kg/m(2)) and higher mortality risks by any cause were stronger among lower income groups. Even adjusting for multiple confounding factors, hazard ratios (95% confidence intervals) for mortality by all causes among low income group (household income<1.5 million yen) were 1.96 (1.02-3.73) for overweight compared with BMIs between 23.0 and 24.9, whereas they were 0.94 (0.57-1.38) among men in high income group (income>3 million yen). The modifying effects of income were not marked among women.

CONCLUSION

Household income, which may directly reflect accessibility to healthcare and psychosocial stress among older Japanese men, may be an important modifying factor in the health risks attributable to overweight.

Distance to retail stores and risk of being homebound among older adults in a city severely affected by the 2011 Great East Japan Earthquake

Background: after the Great East Japan Earthquake in 2011, inactivity and the homebound status of older victims in affected areas have been a serious public health concern owing to the victims' prolonged existence as evacuees in mountainous areas.

Objective: to evaluate the association between distances to retail stores and risks of being homebound.

Design: secondary analysis of cross-sectional interview survey data with a geographical information analysis.

Setting: Rikuzentakata, Iwate, a municipality seriously damaged by the 2011 earthquake and tsunami.

Subjects: all Rikuzentakata residents aged 65 or older except for those living in temporary housing (n = 2,327).

Methods: we calculated road distances between each residential address and retail stores, hawker sites and shopping bus stops, accounting for the extra load caused by walking on slopes. The prevalence ratio of being homebound adjusted for age, source of income and morbidity by road distance was estimated using Poisson regression with a generalised estimating equation.

Results: those living at distances of 1,200 m or more were 1.78 (95% confidence intervals, 1.03–3.08) times more likely to be homebound (going out only every 4 or more days a week) among men and 1.85 (1.13-3.02) among women, compared with those residing in places <400 m from retail stores or shopping bus stops. The distances were reduced by new hawker and shopping bus services, but the improvements varied greatly across the districts.

Conclusions: access to daily needs is essential to prevent homebound status. Post-disaster community diagnosis in terms of the built environment is important for strategic community restoration.

The development of laboratory tests for cancer in Japan with special reference to carcinoembryonic proteins

The present paper describes the present status of clinical tests for cancer in Japan. Since no cancer-specific substance has been found so far the clinical tests for cancer at present are always quantitative but not qualitative. Among these substances, alpha-fetoprotein is one of the most specific substances for cancer and its test is essential for diagnosis of hepatoma beins used worldwide. AFP is a specific product of liver cancer cells. The measurement of carcinoembryonic antigen in patient blood is a hopeful method for cancer diagnosis. This substance is not specifically produced by cancer cells, but the phenomenon of appearance in bloodstream appears to be cancer-specific. This may reflect the invasion of blood vessels in tissues such as colorectum, lung, etc., by infiltration of cancer cell. This is the reason for the appearance of CEA in a wide variety of cancers. There are many other clinical tests at present but these are only secondary aids for the diagnosis of cancer. This is the reason why the description concentrates mostly on AFP and CEA. The companies manufacturing the kits for these tests in Japan are also listed in this paper.

Access disparity and health inequality of the elderly: unmet needs and delayed healthcare

The purpose of this study is to investigate healthcare access disparity that will cause delayed and unmet healthcare needs for the elderly, and to examine health inequality and healthcare cost burden for the elderly. To produce clear policy applications, this study adapts a modified PRECEDE-PROCEED model for framing theoretical and experimental approaches. Data were collected from a large collection of the Community Tracking Study Household Survey 2003-2004 of the USA. Reliability and construct validity are examined for internal consistency and estimation of disparity and inequality are analyzed by using probit/ols regressions. The results show that predisposing factors (e.g., attitude, beliefs, and perception by socio-demographic differences) are negatively associated with delayed healthcare. A 10% increase in enabling factors (e.g., availability of health insurance coverage, and usual sources of healthcare providers) are significantly associated with a 1% increase in healthcare financing factors. In addition, information through a socio-economic network and support system has a 5% impact on an access disparity. Income, health status, and health inequality are exogenously determined. Designing and implementing easy healthcare accessibility (healthcare system) and healthcare financing methods, and developing a socio-economic support network (including public health information) are essential in reducing delayed healthcare and health inequality.

Social participation and the prevention of functional disability in older Japanese: the JAGES cohort study

BACKGROUND

We examined the relationship between incident functional disability and social participation from the perspective of number of types of organizations participated in and type of social participation in a prospective cohort study.

METHOD

The study was based on the Aichi Gerontological Evaluation Study (AGES) Cohort Study data. We followed 13,310 individuals aged 65 years or older for 4 years. Analysis was carried out on 12,951 subjects, excluding 359 people whose information on age or sex was missing. Social participation was categorized into 8 types.

RESULTS

Compared to those that did not participate in any organizations, the hazard ratio (HR) was 0.83 (95% CI: 0.73-0.95) for participation in one, 0.72 (0.61-0.85) for participation in two, and 0.57 (0.46-0.70) for participation in three or more different types of organizations. In multivariable adjusted models, participation in the following types of organization was protective for incident disability: local community organizations (HR = 0.85, 95% CI: 0.76-0.96), hobby organizations (HR = 0.75, 95% CI: 0.64-0.87), and sports organizations (HR = 0.64, 95% CI: 0.54-0.81).

CONCLUSION

Social participation may decrease the risk of incident functional disability in older people in Japan. This effect may be strengthened by participation in a variety of different types of organizations. Participating in a local community, hobby, or sports group or organization may be especially effective for decreasing the risk of disability.

Abstract A272: Intermittent treatment with TAS-120, an irreversible FGFR inhibitor, is effective in tumors harboring a FGFR gene abnormality

Background: FGFs (fibroblast growth factors) and their receptors (FGFRs) play crucial roles in regulation of cell proliferation, survival, migration and differentiation. Deregulation of FGFR expression has been reported in multiple cancers, including breast, bladder, lung, gastric, endometrial and multiple myeloma. FGFRs are overactivated by several mechanisms such as gene amplification, translocation and mutations. FGFR gene alterations are reported in a variety of cancers. We have identified a highly potent, irreversible and selective FGFR inhibitor, TAS-120 (1). In this report, we investigated FGFR turnover in human cancer cell lines. Moreover, we present the antitumor efficacy and pharmacodynamic (PD) activity of TAS-120 in xenograft tumor models to determine the optimal dosing schedule.

Materials and Methods: For in vitro turnover experiments, cell lines were treated with Brefeldin A which suppresses de novo protein synthesis. The cellular level of FGFR was determined by ELISA. For in animal efficacy studies, FGFR2 gene amplified human tumor cell lines were subcutaneously transplanted into the side flank of nude mice or rats. Dosing of compound was started when transplanted tumor size reached &gt; ∼ 200 mm3. For antitumor efficacy, tumor size was measured with digital calipers. To determine the optimal dosing schedule of TAS-120 in a human tumor xenograft model, we orally administered TAS-120 by daily, every other day and other intermittent dosing schedule. The time course of phospho-FGFR inhibition in tumor after single dosing of TAS-120 was also examined as a pharmacodynamic marker.

Results: FGFR turnover was investigated in 2 human cancer cell lines, OCUM-2M (gastric cancer cell line with FGFR2 amplification) and OPM-2 (multiple myeloma cell line with FGFR3 gene translocation). When cells were treated with Brefeldin A, cellular FGFR levels were reduced to &lt; 20% at 4 and 6 hr respectively. FGFR turnover in these cells is rapid as most FGFR protein was replaced within 4 or 6 hr. In animal studies, we determined the PD/efficacy correlation. The time course of phosphor-FGFR inhibition in tumor at efficacious doses suggests that continuous inhibition of the target is not necessary to maintain efficacy. Additional studies in OCUM-2MD3 and SNU-16 models demonstrated that TAS-120 is efficacious even with intermittent dosing schedules of every other day or twice/week schedule.

Conclusion: TAS-120 is a highly potent, selective, irreversible FGFR inhibitor, which demonstrated strong tumor growth inhibition across continuous and intermittent dosing schedules in mice and rat xenograft models.

1) 24th EORTC-NCI-AACR Symposium (2012) abstract #380 & #383

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A272.

Citation Format: Yoko Nakatsuru, Hiroaki Ochiiwa, Hiroshi Sootome, Hidenori Fujita, Akihiro Hashimoto, Yoshihiro Shibata, Masato Chiba, Yayoi Fujioka, Kazuhiro Yonekura, Hiroshi Hirai, Teruhiro Utsugi. Intermittent treatment with TAS-120, an irreversible FGFR inhibitor, is effective in tumors harboring a FGFR gene abnormality. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr A272.

Abstract A269: A selective Aurora A inhibitor, TAS-119, enhanced the antitumor activity of taxanes in an intermittent dosing schedule without affecting neurotoxicity

Background: Aurora A is a serine/threonine kinase that plays important roles in the regulation of the M phase of the mammalian cell cycle. Aberrant expression of Aurora A has been associated with spindle checkpoint dysfunction and increased resistance to the microtubule-polymerizing agents, paclitaxel and docetaxel (1). Moreover, Aurora A overexpression/ gene amplification has been reported in various types of human cancers. Previously, we have reported on the development of a highly potent and selective Aurora A inhibitor, TAS-119 (TAS-2104), which enhanced anti-proliferation activity by taxanes (2). This study was undertaken to select the optimal combination schedule of TAS-119 and taxanes both in vitro and in vivo. Additionally, we evaluated the effects of TAS-119 on peripheral neurotoxicity, a well known major toxicity of taxanes.

Materials and Methods: For in vitro experiments, cells were exposed to paclitaxel and/or the Aurora A inhibitor in different order and duration. Cell viability was determined by measuring cellular ATP concentration. For an in vivo tumor efficacy study, human tumor cell lines were subcutaneously transplanted into the side flank of nude mice or rats. Dosing of taxanes and TAS-119 was started when the transplanted tumor size reached &gt; ∼ 200 mm3. Peripheral neurotoxicity was evaluated in rats. Paclitaxel was dosed weekly for 8 weeks and neurotoxicity was assayed by changes of action potential (M-wave amplitude) after electrical stimuli or histopathology changes in nerve neurons.

Results: In in vitro experiments, the Aurora A inhibitor enhanced paclitaxel activity in all 3 schedules tested; Aurora A inhibitor before or after paclitaxel or simultaneous treatment. However, the latter 2 schedules were better than first schedule. When different treatment duration times of the Aurora A inhibitor combined with a single dose of paclitaxel were tested, 48 hrs was found to be enough to cause maximum enhancement. Similar experiments were performed in in vivo xenograft models. Maximum enhancement by TAS-119 was observed with 2 to 4 days of treatment (dependent on the model). Moreover, the combination of TAS-119 did not exacerbate the paclitaxel-induced peripheral neurotoxicity in rats.

Conclusion: In this study, intermittent dosing of TAS-119 is efficacious for combination with taxanes, and sustained exposure of TAS-119 is not required for maximal combination efficacy. These findings provide a rationale for the clinical evaluation of combination therapies of TAS-119 with taxanes under the defined optimal schedule.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A269.

Citation Format: Keiko Ishihara, Hiroshi Sootome, Takamasa Suzuki, Norio Masuko, Akihiro Miura, Megumu Okada, Nobuyuki Oda, Hiroshi Hirai, Teruhiro Utsugi. A selective Aurora A inhibitor, TAS-119, enhanced the antitumor activity of taxanes in an intermittent dosing schedule without affecting neurotoxicity. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr A269.