Emerging clinical phenotype of bone metastatic urothelial cancer (mUC): Association of early osseous metastases (EOM) and outcomes

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Background: Outcomes of patients (pts) with mUC with EOM have not thoroughly been described in the age of immuno-oncology. We hypothesized that EOM is associated with worse outcomes when compared to pts with non-osseous metastases (NOM). Methods: We used a multi-institutional database of pts with mUC who received systemic treatment (trt) between March 2005 and August 2019, to assess survival and palliative outcomes of pts with EOM vs NOM at the time of metastatic diagnosis (met dx). Wilcoxon rank-sum and chi-square tests were performed. Survival was estimated by Kaplan-Meier method, Cox regression analysis was performed. Results: We identified 270 pts, 72% men, mean age 67 ± 11 years, 28% never smokers. At met dx, 27% (n = 72) had ≥ 1 EOM; these pts were more likely to have de novo metastases vs. those with recurrent metastases (42% vs 19%, p < 0.001). Pts with EOM were more likely to have a change or stop in 1st line trt due to clinical progression (30.6% vs 15.7%, p = 0.006), and received fewer total lines of systemic trt, median of 1.0 (1.0-5.0) vs. 2.0 (1.0-8.0), p = 0.05. Pts with EOM had shorter median overall survival (OS) vs. those with NOM, (6.1 vs 13.7 months, p < .0001), HR = 2.79 (95% CI:1.95-3.97, p < .0001). Median OS was shorter for pts with EOM who received 1st line immune checkpoint inhibitor (n = 14) vs platinum-based chemotherapy (n = 43), (1.6 vs 9.1 months, p = 0.003). Pts with EOM received higher opioid analgesic doses at the first and last oncology outpatient visits compared to pts with NOM with mean morphine milligram equivalent (MME) dose of 60 ± 91 vs 28 ± 65 at first visit, p = 0.004, and 171 ± 214 vs. 94 ± 229 at last visit, p < 0.001. Conclusions: The presence of EOM in mUC is associated with worse outcomes vs. pts with NOM. Pts with EOM may benefit from 1st line platinum-based chemotherapy vs. checkpoint immunotherapy. Furthermore, pts with EOM experience more pain than pts with NOM and may benefit from early engagement with palliative care. Pts with EOM represent a population with a highly unmet need for systemic, targeted and/or radiation interventions. Molecular subtypes may further define these pts and analysis is planned. We encourage ongoing clinical trials to report outcomes in pts with EOM. A consensus on reporting of non-measurable disease is also needed. [Table: see text]

Effect of β-hydroxy-β-methylbutyrate (HMB) on muscle strength in older men with prostate cancer (Pca) started on androgen deprivation therapy (ADT): Preliminary results of an open-label, randomized trial

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Background: ADT causes muscle weakness and wasting within 3 months (mo), causing older men on ADT to experience functional impairments and falls. HMB, a leucine metabolite which decreases muscle protein breakdown, improves strength, fat-free mass and function in older patients when given with arginine (A) and glutamine (G). Use of HMB +AG in older men with PCa starting on ADT to improve muscle loss and function has not been reported. Methods: Men age ≥ 60 with Pca starting on ADT were eligible. 42 men to date have been randomized to receive HMB + AG (Juven) twice daily for 3 mo vs no supplement. Physical performance measures using the Short Physical Performance Battery (SPPB) and hand dynamometer measurements were done at baseline and 3 mo. Both of these validated tests predict morbidity and mortality in older patients. Information on primary outcome, body composition, will be reported in the future according to study plan. Interim results are reported here to describe functional geriatric outcomes. Results: 42 men (mean age 70.2) with Pca (42.4% localized, 27.3% biochemical recurrence, 30.3% metastatic) have enrolled to date. Change in SPPB score favored HMB group: 12.6% of HMB vs 23.1% of controls had decline of ≥ 1point (pt) and 56.3% of HMB vs 15.4% of controls had increase of ≥ 1 pt (p = 0.045). The change in timed chair stand portion of SPPB (measures quadriceps strength) trended in favor of HMB group: -1.5 ± 2.9 seconds (sec) for HMB vs +0.4 ± 2.5 sec for controls, p = 0.073. 41.2% of HMB vs 15.4% of controls experienced an improvement in chair stand score. Change in hand grip strength also favored HMB group: 52.9% of HMB vs 84.6% of controls lost strength and 29.4% of HMB vs 0 controls gained strength, p = 0.047. No significant side effects were reported in HMB group. Conclusions: These are preliminary results of an ongoing trial. HMB is well tolerated in men with PCa on ADT. There is a trend in all measures of muscle function in favor of the HMB group. A much higher than expected % of men on HMB experienced improvement in measures of muscle function despite being on ADT. Further studies are ongoing to clarify the role of HMB in older men on ADT. Clinical trial information: NCT01607879.

Liver-directed therapy (LDT) for metastatic renal cell carcinoma (mRCC): Single center experience

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Background: Liver metastases arising from RCC are common and signify a poor prognosis. Given the negative impact of liver metastases on overall survival (OS) and quality of life, it is reasonable to to consider therapies directly targeting these lesions in select patients. Little is known about how minimally invasive LDT affects outcomes in patients with mRCC. Methods: Nine patients with mRCC underwent LDT for liver-dominant or liver-only metastatic disease between 2005 and 2015. Retrospective chart review was performed under an IRB protocol to identify patient and disease characteristics, imaging response, and time to next systemic treatment, OS and toxicities. Patients were seen in clinic at one month post-LDT to monitor for toxicities. Imaging was obtained within 2 months prior to treatment and at 3 and 6 months following LDT. Results: Each patient underwent a median of 2.3 procedures. A total of 18 transarterial chemoembolizations (TACE) and 5 yttrium-90 radioembolizations were performed. 2 patients had metastatic disease confined to the liver, and 7 had liver-dominant disease. 7 had multifocal disease involving < 25% of the liver, and 2 had multifocal disease involving > 25% of the liver. 8/9 patients received prior systemic therapies, receiving a median of 3 (0-4) distinct treatments. 4/9 patients were undergoing systemic therapy at the time of LDT, 1 patient declined further treatment, and the median time to initiation of the next systemic therapy in the remaining patients was 3 months (range 2-4 months). Median OS from first line systemic therapy was 39 months, 95% CI [25.9-53.3], and the median OS from the first LDT was 22 months (from 5-45 months). Follow-up imaging post-LDT showed PR or SD in 88% of cases at 3 months and 44% of cases at 6 months. At one month post-procedure, 8/9 patients maintained performance status, and only one patient experienced CTCAE grade 3-4 toxicity. Conclusions: The median OS in RCC patients with liver disease and systemic therapy alone is 14.3 months. The improved median OS of 39 months with LDT in our unmatched and heavily pretreated cohort suggests a role for LDT. LDT is generally well tolerated and should be considered for patients with liver-dominant mRCC with good performance status.

Epacadostat plus nivolumab in patients with advanced solid tumors: Preliminary phase I/II results of ECHO-204

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Background: ECHO-204 is an ongoing, open-label, phase 1/2 (P1/2) study of epacadostat (E; potent and selective oral inhibitor of the immunosuppressive enzyme indoleamine 2,3-dioxygenase 1) plus PD-1 inhibitor nivolumab (N) in patients (pts) with advanced cancers (NSCLC, MEL, OVC, CRC, SCCHN, B-cell NHL [including DLBCL], GBM). Preliminary P1/2 safety and tolerability outcomes for the overall study population and P2 response for select tumor types (SCCHN, MEL, OVC, CRC) are reported. Methods: In P1 dose escalation, pts received E (25, 50, 100, 300 mg BID) + N (3 mg/kg Q2W); in P2 cohort expansion, pts received E (100 or 300 mg BID) + N (240 mg Q2W). Safety/tolerability was assessed in pts receiving ≥1 E + N dose. Response was assessed in RECIST v1.1 evaluable pts; for recently enrolled pt subgroups, only preliminary DCR (CR+PR+SD) is presented. Results: As of 29OCT2016,241 pts (P1, n = 36; P2, n = 205) were enrolled. No DLT was observed in P1. Most common TRAEs (≥15%) in pts treated with E 100 mg (n = 70) and E 300 mg (n = 135) were rash (33% and 22%, respectively), fatigue (26% and 31%), and nausea (24% and 19%). Rash was the most common grade ≥3 TRAE in E 100 mg and E 300 mg subgroups (10% and 12%). TRAEs led to discontinuation in 7% (E 100 mg) and 13% (E 300 mg) of pts. There were no TR-deaths. For the 23 recently enrolled, efficacy-evaluable SCCHN pts treated with E 300 mg, preliminary DCR was 70% (n = 16). Of 30 MEL pts, 8 were treated with E 100 mg and 22 were more recently enrolled and treated with E 300 mg. ORR (CR+PR) and DCR in MEL pts treated with E 100 mg were 75% (n = 6; all PR) and 100% (n = 8; 2 SD), respectively. Preliminary DCR in MEL pts treated with E 300 mg was 64% (n = 14). Of 29 OVC pts, 18 were treated with E 100 mg and 11 with E 300 mg.ORR and DCR for OVC pts treated with E 100 mg were 11% (n = 2; 2 PR) and 28% (n = 5; 3 SD); for 11 OVC pts treated with E 300 mg, ORR and DCR were 18% (n = 2; 2 PR) and 36% (n = 4; 2 SD).For 25 CRC pts (all E 100 mg), ORR and DCR were 4% (n = 1; PR) and 24% (n = 6; 5 SD).Safety/efficacy evaluations are ongoing for all cohorts. Conclusions: E + N was generally well tolerated up to the maximum E 300-mg dose. P2 ORR/DCR outcomes are promising, particularly in SCCHN and MEL pts. Updated data will be presented at the meeting. Clinical trial information: NCT02327078.

Safety and clinical activity of adenosine A2a receptor (A2aR) antagonist, CPI-444, in anti-PD1/PDL1 treatment-refractory renal cell (RCC) and non-small cell lung cancer (NSCLC) patients

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Background: Adenosine production in the tumor leads to immunosuppression through A2aR on infiltrating immune cells. CPI-444 is an oral A2aR antagonist with single agent(SA) anti-tumor activity in pre-clinical models. This phase 1/1b clinical trial uses a 2-step adaptive design to evaluate CPI-444 as a SA and in combination (combo) with the anti-PDL1 antibody, atezolizumab (atezo). We report results of RCC and NSCLC cohorts. Methods: Primary objectives: safety, efficacy and to identify optimal dose/schedule. Step 1 utilized 3 SA and 1 combo cohort to select dose/schedule. Step 2 included disease-specific expansion cohorts including RCC and NSCLC. Eligible pts had selected advanced cancers and failed standard therapies including checkpoint inhibitors. Results: 34 pts have enrolled and 25 pts were evaluable for response (Table 1). Median prior regimens: 3 (range,1-5) and most pts were resistant/refractory to anti PD1/PDL1 therapy (R/R). Most common AEs were Gr 1 nausea (n = 3) and pyrexia (n = 3); Gr 3 tachycardia was the only possibly related SAE. The selected Step 2 doses were CPI-444 100mg BID as a SA and in combo with atezo 840mg IV q2 weeks. The disease control rate (DCR, CR+PR+SD; duration 2 mo to > 8 mo) for pts with RCC and NSCLC cohorts were 86% and 50%, (100% and 43% for R/R pts), respectively. DCRs were similar in the SA and combo cohorts. Of 7 evaluable RCC pts, 1 pt has an ongoing PR (SA cohort, > 4 mo) and 5 have ongoing SD, duration 3 mo to > 8 mo (2 SA, 3 combo). Biopsy of the PR pt showed no detectable tumor and infiltration with CD8+ lymphocytes. In 18 evaluable NSCLC pts, 1 PR (PDL1 negative pt) and 8 SD were seen. PRs and SDs were seen in R/R pts and in PDL1 negative pts in both diseases. Conclusions: CPI-444 is well tolerated and shows anti-tumor activity in RCC and NSCLC pts as a SA and in combo. Pts who are R/R to anti PD1/PDL1 therapy and who are PDL1 negative can also benefit. Clinical trial information: NCT02655822. [Table: see text]

ADP ribosylation of Arg41 of Rap by ExoS inhibits the ability of Rap to interact with its guanine nucleotide exchange factor, C3G

ExoS is a bifunctional type III cytotoxin that is secreted by Pseudomonas aeruginosa. The N-terminal domain comprises a RhoGAP activity, while the C-terminal domain comprises a ADP-ribosyltransferase activity. Previous studies showed that ExoS ADP ribosylated Ras at Arg41 which interfered with the ability of Ras to interact with its guanine nucleotide exchange factor. Rap and Ras share considerable primary amino acid homology, including Arg41. In this study, we report that ExoS ADP ribosylates Rap1b at Arg41 and that ADP ribosylation of Arg41 inhibits the ability of C3G to stimulate guanine nucleotide exchange. The mechanism responsible for this inhibition is one in which ADP-ribosylated Rap binds inefficiently to C3G, relative to wild type Rap. This identifies a second member of the Ras GTPase subfamily that can be ADP ribosylated by ExoS and indicates that ExoS can inhibit both Ras and Rap signaling pathways in eukaryotic cells.

A genetic screen for modifiers of Drosophila decapentaplegic signaling identifies mutations in punt, Mothers against dpp and the BMP-7 homologue, 60A

decapentaplegic (dpp) is a Transforming Growth Factor beta (TGF-beta)-related growth factor that controls multiple developmental processes in Drosophila. To identify components involved in dpp signaling, we carried out a genetic screen for dominant enhancer mutations of a hypomorphic allele of thick veins (tkv), a type I receptor for dpp. We recovered new alleles of tkv, punt, Mothers against dpp (Mad) and Medea (Med), all of which are known to mediate dpp signaling. We also recovered mutations in the 60A gene which encodes another TGF-beta-related factor in Drosophila. DNA sequence analysis established that all three 60A alleles were nonsense mutations in the prodomain of the 60A polypeptide. These mutations in 60A caused defects in midgut morphogenesis and fat body differentiation. We present evidence that when dpp signaling is compromised, lowering the level of 60A impairs several dpp-dependent developmental processes examined, including the patterning of the visceral mesoderm, the embryonic ectoderm and the imaginal discs. These results provide the first in vivo evidence for the involvement of 60A in the dpp pathway. We propose that 60A activity is required to maintain optimal signaling capacity of the dpp pathway, possibly by forming biologically active heterodimers with Dpp proteins.