A phase 1b study (STELLAR-002) of XL092 administered in combination with nivolumab (NIVO) with or without ipilimumab (IPI) or bempegaldesleukin (BEMPEG) in patients (pts) with advanced solid tumors

TPS4600

Background: XL092 is a novel oral inhibitor of receptor tyrosine kinases, including MET, VEGFR2, and TAM kinases (AXL, MER), which are implicated in tumor growth, metastasis, angiogenesis, and immune suppression of the tumor microenvironment. XL092 has a relatively short half-life (̃21h) to support convenient daily dosing and help manage tolerability. Preclinical studies of XL092 with an anti‒PD-1 immune checkpoint inhibitor (ICI) demonstrated antitumor activity in tumor models, and BEMPEG (IL-2 pathway agonist) showed synergy with anti‒PD-L1 and anti‒CTLA-4 agents. This phase 1b trial will evaluate the safety and clinical activity of XL092 alone and in combination with NIVO (anti‒PD-1 mAb) ±IPI (anti‒CTLA-4 mAb) or ±BEMPEG in pts with advanced solid tumors including genitourinary cancers. Presented here is the study design. Methods: This multicenter phase 1b, open-label study (NCT05176483) will enroll pts with unresectable advanced or metastatic solid tumors in dose-escalation and expansion stages. In the dose-escalation stage, ̃36 pts will be enrolled in three XL092 combination therapy cohorts using a rolling 6 design. Cohort A: XL092 (starting dose [SD] 100 mg PO QD) + NIVO (360 mg IV Q3W); Cohort B: XL092 (SD 80 mg PO QD) + NIVO (3 mg/kg IV Q3W × 4, then 480 mg IV Q4W) + IPI (1 mg/kg Q3W × 4); Cohort C: XL092 (SD 100 mg PO QD) + NIVO (360 mg IV Q3W) + BEMPEG (0.006 mg/kg IV Q3W). The primary objective of the dose-escalation stage is to determine the recommended doses of XL092 with the NIVO regimens to be used in the expansion stage. The expansion stage will include cohorts of advanced genitourinary tumors: Cohort 1, clear-cell renal cell carcinoma (ccRCC), no prior systemic therapy; Cohort 2, ccRCC, 1 prior ICI combination regimen; Cohort 3, metastatic castration-resistant prostate cancer (mCRPC), 1 prior novel-hormonal therapy; Cohort 4, urothelial carcinoma (UC), 1 prior platinum-based regimen, ICI-naïve; Cohort 5, UC, ≤2 prior systemic regimens, ICI-experienced; Cohort 6, non-ccRCC, no prior systemic therapy. In each cohort, pts will be randomized to one of the following treatments (based on tumor cohort): single-agent XL092 (Cohorts 2‒6); XL092+NIVO (Cohorts 1‒6); NIVO+IPI (Cohort 1); XL092+NIVO+IPI (Cohorts 1, 3, 6); NIVO+BEMPEG (Cohort 1), XL092+NIVO+BEMPEG (Cohort 1, 2, 4‒6). Thirty pts will be enrolled in each single-agent XL092 arm and 40 pts in each combination therapy arm. Expansion stage objectives are to assess preliminary efficacy, safety, and pharmacokinetics of XL092 alone or in combination in each tumor-specific cohort. Primary efficacy endpoints include objective response rate by investigator per RECIST v1.1 and progression-free survival by blinded independent radiology committee per Prostate Working Group 3 criteria (mCRPC cohort only). The study is currently enrolling pts. Clinical trial information: NCT05176483.

A Phase Ib Study of Atezolizumab with Radium-223 Dichloride in Men with Metastatic Castration-Resistant Prostate Cancer

PURPOSE

Men with metastatic castration-resistant prostate cancer (mCRPC) have limited treatment options after progressing on hormonal therapy and chemotherapy. Here, we evaluate the safety and efficacy of atezolizumab (anti-PD-L1) + radium-223 dichloride (radium-223) in men with mCRPC.

PATIENTS AND METHODS

This phase Ib study evaluated atezolizumab + radium-223 in men with mCRPC and bone and lymph node and/or visceral metastases that progressed after androgen pathway inhibitor treatment. Following safety assessment of concurrent dosing, 45 men were randomized 1:1:1 to concurrent or one of two staggered dosing schedules with either agent introduced one cycle before the other. This was followed by a safety-efficacy expansion cohort (randomized 1:1:1). The primary endpoints were safety and objective response rate (ORR) by RECIST 1.1. Secondary endpoints included radiographic progression-free survival (rPFS), PSA responses, and overall survival (OS).

RESULTS

As of October 4, 2019, 44 of 45 men were evaluable. All 44 had ≥1 all-cause adverse event (AE); 23 (52.3%) had a grade 3/4 AE. Fifteen (34.1%) grade 3/4 and 3 (6.8%) grade 5 AEs were related to atezolizumab; none were related to radium-223. Confirmed ORR was 6.8% [95% confidence interval (CI), 1.4-18.7], median rPFS was 3.0 months (95% CI, 2.8-4.6), median PSA progression was 3.0 months (95% CI, 2.8-3.3), and median OS was 16.3 months (95% CI, 10.9-22.3).

CONCLUSIONS

This phase Ib study demonstrated that atezolizumab + radium-223, regardless of administration schedule, had greater toxicity than either drug alone, with no clear evidence of additional clinical benefit for patients with mCRPC and bone and lymph node and/or visceral metastases.

Molecular Subsets in Renal Cancer Determine Outcome to Checkpoint and Angiogenesis Blockade

Integrated multi-omics evaluation of 823 tumors from advanced renal cell carcinoma (RCC) patients identifies molecular subsets associated with differential clinical outcomes to angiogenesis blockade alone or with a checkpoint inhibitor. Unsupervised transcriptomic analysis reveals seven molecular subsets with distinct angiogenesis, immune, cell-cycle, metabolism, and stromal programs. While sunitinib and atezolizumab + bevacizumab are effective in subsets with high angiogenesis, atezolizumab + bevacizumab improves clinical benefit in tumors with high T-effector and/or cell-cycle transcription. Somatic mutations in PBRM1 and KDM5C associate with high angiogenesis and AMPK/fatty acid oxidation gene expression, while CDKN2A/B and TP53 alterations associate with increased cell-cycle and anabolic metabolism. Sarcomatoid tumors exhibit lower prevalence of PBRM1 mutations and angiogenesis markers, frequent CDKN2A/B alterations, and increased PD-L1 expression. These findings can be applied to molecularly stratify patients, explain improved outcomes of sarcomatoid tumors to checkpoint blockade versus antiangiogenics alone, and develop personalized therapies in RCC and other indications.

Cost of cystectomy-related complications in patients with bladder cancer in the United States

Aims: To describe healthcare utilization and cost associated with the short-term and long-term complications of cystectomy among commercially insured bladder cancer patients in the United States.Materials and methods: This retrospective, observational cohort study evaluated adults with bladder cancer receiving a transurethral resection of bladder tumor followed by a partial or radical cystectomy procedure using U.S. administrative claims from the 2005-2015 IBM MarketScan Commercial and Medicare Supplemental databases. Bladder cancer patients were classified into two cohorts: partial cystectomy or radical cystectomy. Cystectomy complications were identified during the cystectomy admission, short-term period, and long-term period. Complication-related utilization and cost outcomes were reported in aggregate during the cystectomy admission and per patient per month (PPPM) during the short-term and long-term follow-up periods.Results: Of 5136 patients who received a cystectomy, 488 (9.5%) received partial cystectomy and 4648 (90.5%) received radical cystectomy. The mean (SD) costs of complications during the cystectomy admission were $11,728 ($43,380) for radical cystectomy and $4657 ($25,668) for partial cystectomy. In the short-term period, PPPM complication-related healthcare costs were $638 [$3793] for partial cystectomy and $2681 [$14,705] for radical cystectomy. In the long-term period, PPPM complication-related healthcare costs were $544 [$2580] for partial cystectomy and $1619 [$7874] for radical cystectomy.Conclusions: Cystectomy-related complications, especially with radical cystectomy, present a substantial financial burden to patients and payers immediately after surgery as well as in the long term. Targeted interventions which improve clinical outcomes but reduce substantial costs associated with cystectomy for bladder cancer are needed.

Safety and clinical activity of atezolizumab (atezo) + radium-223 dichloride (r-223) in 2L metastatic castration-resistant prostate cancer (mCRPC): Results from a phase Ib clinical trial

5565

Background: mCRPC patients (pts) tend to have a poor prognosis and limited treatment (tx) options, especially those with concomitant bone metastases (mets). We explored the ability of combination tx with atezo (anti–PD-L1) and r-223 (α-particle emitter) to stimulate anti-tumor immunity in mCRPC pts. Methods: This Phase Ib study evaluated the safety and tolerability of atezo + r-223 in pts with mCRPC and multiple bone mets, visceral mets and/or lymphadenopathy who progressed after androgen pathway inhibitor tx. The initial cohort phase evaluated the safety and tolerability of a concurrent dosing schedule (CDS), in which atezo and r-223 were administered on the same day. Following assessment of CDS, pts were randomized 1:1:1 to CDS or 1 of 2 staggered dosing schedules (atezo or r-223 introduced a full cycle before the other). This was followed by an expansion of enrollment (randomized 1:1:1). Pts got atezo 840 mg IV q2w and r-223 at 55 kBq/kg IV 6 times at 4-wk intervals until unacceptable toxicity or loss of clinical benefit. Exploratory measures of efficacy included investigator-assessed ORR (RECIST 1.1), PSA response rate, time to PSA progression, radiographic PFS (rPFS; PCWG2 criteria) and OS. Biopsy samples were collected at baseline and prior to cycle 2 to evaluate changes in the tumor microenvironment during tx. Results: As of Oct 4, 2019, 45 pts were enrolled and 44 had evaluable data. Baseline characteristics were generally similar across groups. All 44 evaluable pts had ≥ 1 all-cause AE; 23 (52.3%) had Gr 3-4 AE. Eight pts (18.2%) had Gr 5 AE as per protocol reporting of deaths; 4 (9.1%) were from disease progression. Median follow-up was 13.9 mo (range, 1.7–34.2). Confirmed ORR was 6.8% (95% CI: 1.43, 18.66). Confirmed PSA response rate was 4.5% and median time to PSA progression was 3.0 mo (95% CI: 2.8, 3.3). Median rPFS was 3.0 mo (95% CI: 2.8, 4.6) and median OS was 16.3 mo (95% CI: 10.9, 22.3). Changes in PD-L1 and CD8 IHC were consistent with the known mechanism of action of atezo, as were changes in alkaline phosphatase with radium. Conclusions: No dose-limiting toxicities, safety signals, or changes in serum biomarkers were observed beyond the known safety profiles of atezo and r-223. This Phase 1b study did not seem to show clinical benefit from combination tx. Ongoing subgroup and biomarker analyses may provide additional insights. Studies of PD-1/PD-L1 targeted therapies in combination with tumor-directed radiation in molecularly selected mCRPC pts are planned or underway. Clinical trial information: NCT02814669 .

Tumor, immune, and stromal characteristics associated with clinical outcomes with atezolizumab (atezo) + platinum-based chemotherapy (PBC) or atezo monotherapy (mono) versus PBC in metastatic urothelial cancer (mUC) from the phase III IMvigor130 study

5011

Background: Tumor mutational burden (TMB), PD-L1 expression, T-effector gene expression (GE) and a fibroblast TGF-β–response signature (F-TBRS) are associated with clinical outcomes with atezo mono in mUC (Mariathasan, Nature, 2018). Here we explore the potential predictive role of these biomarkers and APOBEC mutagenesis in IMvigor130. Methods: Pts receiving first-line (1L) mUC treatment (tx) were randomized 1:1:1 to atezo + PBC, atezo mono, or placebo + PBC. Coprimary efficacy endpoints were PFS and OS. Planned exploratory biomarker analyses included PD-L1 expression, TMB (FoundationOne), and T-effector GE (RNA-seq). Results: The 851 biomarker-evaluable pts (BEP) were representative of the 1200 ITT pts. Biomarker results are shown in Table. PD-L1 IC2/3 was associated with significantly longer OS for atezo mono vs placebo + PBC and a combination of PD-L1 IC2/3, and high TMB (> 10 muts/Mb) identified a pt subset (≈ 14% of BEP) with particularly favorable outcomes with atezo mono vs placebo + PBC; similar results for PD-L1 and TMB were not seen with atezo + PBC vs placebo + PBC. APOBEC mutagenesis was associated with improved OS with atezo-containing regimens whereas high F-TBRS was associated with inferior OS with atezo mono. Conclusions: These results reinforce the potential predictive nature of biomarkers associated with response/resistance to atezo and highlight potentially distinct biology driving benefit with atezo and atezo + PBC. These findings suggest a possible biomarker-directed approach to 1L mUC tx that warrants mechanistic interrogation and prospective validation. Clinical trial information: NCT02807636 . [Table: see text]

IMvigor010: Primary analysis from a phase III randomized study of adjuvant atezolizumab (atezo) versus observation (obs) in high-risk muscle-invasive urothelial carcinoma (MIUC)

5000

Background: Radical surgery ± cisplatin-based neoadjuvant chemo (NAC) is the mainstay treatment (tx) for MIUC, with no conclusive level 1 evidence for adjuvant chemo (AC). Here we present the primary analysis from IMvigor010, a global, open-label, multicenter, randomized trial of adjuvant atezo (anti–PD-L1; approved in metastatic UC [mUC] settings) in pts with MIUC at high risk of recurrence following primary resection. Methods: Pts with MIUC (bladder, upper tract [UT]), ECOG PS 0-2 and resected tissue for PD-L1 testing on immune cells (IC; VENTANA SP142 assay) were enrolled ≤ 14 wks after radical cystectomy/nephroureterectomy with lymph node (LN) dissection. Pathologic stage: 1) ypT2-4a or ypN+ if pts had NAC or 2) pT3-4a or pN+ if pts did not have NAC. No postsurgical radiation or AC was allowed; if no NAC was given, pts must have been ineligible for or declined cisplatin-based AC. Pts were randomized 1:1 to atezo 1200 mg IV q3w or obs for 16 cycles or 1 y (stratification factors: no. of LNs resected, pathologic nodal status, pathologic tumor stage, PD-L1 status, prior NAC). Disease-free survival (DFS) was the primary endpoint (EP). Final DFS, first interim overall survival (OS; secondary EP) and safety are reported. Results: The ITT population included 809 pts (median follow-up, 21.9 mo). In the atezo and obs arms, respectively, 48% and 47% had NAC; 7% and 6% had UTUC as primary disease; 48% each had LN+ disease. DFS and OS are in Table. Baseline prognostic/clinical factors did not influence DFS tx benefit; stratified HR was 0.81 (95% CI: 0.63, 1.05) in IC0/1 pts (PD-L1 < 5%; n = 417) and 1.01 (0.75, 1.35) in IC2/3 pts (PD-L1 ≥ 5%; n = 392). 16% of atezo-treated pts had a tx-related G3-4 AE. Skin and gastrointestinal toxicities most commonly led to tx discontinuation. Conclusions: IMvigor010, the first phase 3 adjuvant study of a checkpoint inhibitor in MIUC, did not meet its primary EP of DFS. More tx discontinuation due to AEs was seen vs mUC studies. Safety was generally consistent with previous studies. Clinical trial information: NCT02450331 . [Table: see text]

Atezolizumab with or without chemotherapy in metastatic urothelial cancer (IMvigor130): a multicentre, randomised, placebo-controlled phase 3 trial

BACKGROUND

Atezolizumab can induce sustained responses in metastatic urothelial carcinoma. We report the results of IMvigor130, a phase 3 trial that compared atezolizumab with or without platinum-based chemotherapy versus placebo plus platinum-based chemotherapy in first-line metastatic urothelial carcinoma.

METHODS

In this multicentre, phase 3, randomised trial, untreated patients aged 18 years or older with locally advanced or metastatic urothelial carcinoma, from 221 sites in 35 countries, were randomly assigned to receive atezolizumab plus platinum-based chemotherapy (group A), atezolizumab monotherapy (group B), or placebo plus platinum-based chemotherapy (group C). Patients received 21-day cycles of gemcitabine (1000 mg/m² body surface area, administered intravenously on days 1 and 8 of each cycle), plus either carboplatin (area under the curve of 4·5 mg/mL per min administered intravenously) or cisplatin (70 mg/m² body surface area administered intravenously) on day 1 of each cycle with either atezolizumab (1200 mg administered intravenously on day 1 of each cycle) or placebo. Group B patients received 1200 mg atezolizumab, administered intravenously on day 1 of each 21-day cycle. The co-primary efficacy endpoints for the intention-to-treat population were investigator-assessed Response Evaluation Criteria in Solid Tumours 1.1 progression-free survival and overall survival (group A vs group C) and overall survival (group B vs group C), which was to be formally tested only if overall survival was positive for group A versus group C. The trial is registered with ClinicalTrials.gov, NCT02807636.

FINDINGS

Between July 15, 2016, and July 20, 2018, we enrolled 1213 patients. 451 (37%) were randomly assigned to group A, 362 (30%) to group B, and 400 (33%) to group C. Median follow-up for survival was 11·8 months (IQR 6·1-17·2) for all patients. At the time of final progression-free survival analysis and interim overall survival analysis (May 31, 2019), median progression-free survival in the intention-to-treat population was 8·2 months (95% CI 6·5-8·3) in group A and 6·3 months (6·2-7·0) in group C (stratified hazard ratio [HR] 0·82, 95% CI 0·70-0·96; one-sided p=0·007). Median overall survival was 16·0 months (13·9-18·9) in group A and 13·4 months (12·0-15·2) in group C (0·83, 0·69-1·00; one-sided p=0·027). Median overall survival was 15·7 months (13·1-17·8) for group B and 13·1 months (11·7-15·1) for group C (1·02, 0·83-1·24). Adverse events that led to withdrawal of any agent occurred in 156 (34%) patients in group A, 22 (6%) patients in group B, and 132 (34%) patients in group C. 50 (11%) patients in group A, 21 (6%) patients in group B, and 27 (7%) patients in group C had adverse events that led to discontinuation of atezolizumab or placebo.

INTERPRETATION

Addition of atezolizumab to platinum-based chemotherapy as first-line treatment prolonged progression-free survival in patients with metastatic urothelial carcinoma. The safety profile of the combination was consistent with that observed with the individual agents. These results support the use of atezolizumab plus platinum-based chemotherapy as a potential first-line treatment option for metastatic urothelial carcinoma.

FUNDING

F Hoffmann-La Roche and Genentech.

High systemic and tumor-associated IL-8 correlates with reduced clinical benefit of PD-L1 blockade

Although elevated plasma interleukin-8 (pIL-8) has been associated with poor outcome to immune checkpoint blockade ¹, this has not been comprehensively evaluated in large randomized studies. Here we analyzed circulating pIL-8 and IL8 gene expression in peripheral blood mononuclear cells and tumors of patients treated with atezolizumab (anti-PD-L1 monoclonal antibody) from multiple randomized trials representing 1,445 patients with metastatic urothelial carcinoma (mUC) and metastatic renal cell carcinoma. High levels of IL-8 in plasma, peripheral blood mononuclear cells and tumors were associated with decreased efficacy of atezolizumab in patients with mUC and metastatic renal cell carcinoma, even in tumors that were classically CD8⁺ T cell inflamed. Low baseline pIL-8 in patients with mUC was associated with increased response to atezolizumab and chemotherapy. Patients with mUC who experienced on-treatment decreases in pIL-8 exhibited improved overall survival when treated with atezolizumab but not with chemotherapy. Single-cell RNA sequencing of the immune compartment showed that IL8 is primarily expressed in circulating and intratumoral myeloid cells and that high IL8 expression is associated with downregulation of the antigen-presentation machinery. Therapies that can reverse the impacts of IL-8-mediated myeloid inflammation will be essential for improving outcomes of patients treated with immune checkpoint inhibitors.

Atezolizumab in Platinum-treated Locally Advanced or Metastatic Urothelial Carcinoma: Clinical Experience from an Expanded Access Study in the United States

BACKGROUND

Atezolizumab (anti-programmed death-ligand 1) was approved in the USA, Europe, and elsewhere for treatment-naive and platinum-treated locally advanced/metastatic urothelial carcinoma (mUC).

OBJECTIVE

To report efficacy and safety from an atezolizumab expanded access study.

DESIGN, SETTING, AND PARTICIPANTS

This single-arm, open-label study enrolled 218 patients at 36 US sites. Key eligibility criteria included progression during/following ≥1 platinum-based chemotherapy for mUC or in perioperative setting (progression within 12 mo) and Eastern Cooperative Oncology Group performance status (ECOG PS) 0-2.

INTERVENTION

Patients received atezolizumab1200mg intravenously every 3 wk until loss of clinical benefit, unacceptable toxicity, consent withdrawal, decision to discontinue, death, atezolizumab commercial availability, or study closure.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Key end points reported herein included Response Evaluation Criteria in Solid Tumors v1.1 objective response rate and duration, disease control rate (DCR; response or stable disease), and safety.

RESULTS AND LIMITATIONS

All patients received prior systemic therapy (68% mUC; 27% adjuvant; and 26% neoadjuvant). At baseline, 57% of 214 treated patients had ECOG PS ≥1, 19% had hemoglobin <10g/dl, and 25% had liver metastases. Median treatment duration was 9 wk (interquartile range [IQR], 6-12 wk). Median follow-up duration was 2.3 mo (IQR, 1.6-3.4 mo) overall and 2.7 mo (IQR, 2.0-3.5 mo) in patients not known to have died. Seventeen of 114 evaluable patients (15%) had objective responses (16 ongoing at study termination). DCR was 49%. Treatment-related adverse events (mostly fatigue) occurred in 98 of 214 treated patients.

CONCLUSIONS

The benefit/risk profile of atezolizumab was consistent with that observed in previous studies, despite pretreatment and poor prognostic factors. These results suggest a potential role for atezolizumab in a broader patient range than typically eligible for phase 1-3 studies.

PATIENT SUMMARY

In this expanded access study, atezolizumab was active and tolerable in a range of patients with platinum-treated metastatic urothelial carcinoma.

Atezolizumab in platinum-treated locally advanced or metastatic urothelial carcinoma: post-progression outcomes from the phase II IMvigor210 study

BACKGROUND

Conventional criteria for tumor progression may not fully reflect the clinical benefit of immunotherapy or appropriately guide treatment decisions. The phase II IMvigor210 study demonstrated the efficacy and safety of atezolizumab, a programmed death-ligand 1-directed antibody, in patients with platinum-treated locally advanced or metastatic urothelial carcinoma. Patients could continue atezolizumab beyond Response Evaluation Criteria In Solid Tumors (RECIST) v1.1 progression at the investigator's discretion: this analysis assessed post-progression outcomes in these patients.

PATIENTS AND METHODS

Patients were treated with atezolizumab 1200 mg i.v. every 3 weeks until loss of clinical benefit. Efficacy and safety outcomes in patients who experienced RECIST v1.1 progression and did, or did not, continue atezolizumab were analyzed descriptively.

RESULTS

In total, 220 patients who experienced progression from the overall cohort (n = 310) were analyzed: 137 continued atezolizumab for ≥ 1 dose after progression, 19 received other systemic therapy, and 64 received no further systemic therapy. Compared with those who discontinued, patients continuing atezolizumab beyond progression were more likely to have had a baseline Eastern Cooperative Oncology Group performance status of 0 (43.1% versus 31.3%), less likely to have had baseline liver metastases (27.0% versus 41.0%), and more likely to have had an initial response to atezolizumab (responses in 11.7% versus 1.2%). Five patients (3.6%) continuing atezolizumab after progression had subsequent responses compared with baseline measurements. Median post-progression overall survival was 8.6 months in patients continuing atezolizumab, 6.8 months in those receiving another treatment, and 1.2 months in those receiving no further treatment. Atezolizumab exposure-adjusted adverse event frequencies were generally similar before and following progression.

CONCLUSION

In this single-arm study, patients who continued atezolizumab beyond RECIST v1.1 progression derived prolonged clinical benefit without additional safety signals. Identification of patients most likely to benefit from atezolizumab beyond progression remains an important challenge in the management of metastatic urothelial carcinoma.

CLINICALTRIALS.GOV ID

NCT02108652.

Title: A real-world study of chemotherapy treatment and costs in metastatic urothelial cancer (mUC) patients in the United States

e16009

Background: Cisplatin (CIS)-based regimens are recommended for first-line (1L) treatment of mUC. Carboplatin (CAR) serves as an alternative for patients unfit to receive CIS. This study examined treatment patterns and costs for patients treated with CIS, CAR, and other treatment (OT). Methods: This was a retrospective cohort study of 9,436 patients from a U.S. insurance claims database between 1/1/2005-6/30/2015. Adult patients with ≥ 2 diagnosis codes for UC, ≥ 2 diagnosis codes for metastasis (first metastasis = index date), ≥ 6 months of continuous enrollment pre-index and no evidence of cystectomy were included. Results: The population was majority male (74%); with a mean age of 70. Sixty percent of the mUC patients did not receive 1L chemotherapy during the study period. Among the 3,750 who received treatment, 935 (25%) received 1L CIS, 1,505 (40%) received 1L CAR, and the remaining patients received OT. Patients treated with CIS were younger (62 vs. 69 and 68) and healthier (NCI comorbidity score 0.7 vs. 1.1, and 1.0) vs. patients treated with CAR and OT, respectively. Among CAR patients, 87% received it as combination therapy (CT), with GEM being the most common agent used with CAR. Only 16% of OT patients received CT. Per-patient-per-month (PPPM) 1L all-cause healthcare costs were similar across 1L regimens ($16,540 CIS, $15,739 CAR, and $16,443 OT) and 1L mUC-related healthcare costs were $9,043, $6,975 and $6,191 for CIS, CAR, and OT, respectively. Conclusions: In this real-world study, the majority of mUC patients did not receive 1L chemotherapy, and only a small fraction of those treated received CIS. The remaining patients were treated with CAR or OT, often as monotherapy, which tend to have poorer outcomes compared with CIS. Despite CAR and OT treated patients being younger and healthier, their total health care costs were similar to CIS patients. Newer therapies may provide safer and more efficacious treatment alternatives for patients who are not considered a good fit for CIS therapy.

Atezolizumab (atezo) in platinum-treated locally advanced or metastatic urothelial carcinoma (mUC): Safety analysis from an expanded access study

4532

Background: A majority of mUC pts progress on standard platinum-based chemo regimens. Atezo (anti–PD-L1) was approved in the US for mUC in the post-platinum setting. Here we report the preliminary safety results from an expanded access program conducted to grant access to atezo, prior to commercial availability, to a broader range of mUC pts than are typically eligible for Phase I-III studies. Methods: From Nov 2015-Aug 2016, this study (NCT02589717) enrolled mUC pts who progressed during or following platinum. Atezo was given 1200 mg IV q3w, and pts could be treated post RECIST v1.1 PD until lack of clinical benefit (per investigator). Safety and clinical activity were key endpoints. PD-L1 expression on immune cells (IC) was assessed with the VENTANA SP142 IHC assay on the first 73 pts prior to protocol amendment omitting this requirement. This study was ended early following FDA approval of atezo. Results: 218 pts were enrolled at 36 sites in the US, with 214 treated pts comprising the safety/efficacy population (Table). Median treatment duration was 9 wks (range 3-26), corresponding to a median of 3 doses of atezo (range 1-8). Overall, 89% of pts had an AE. Treatment-related AEs (TRAEs) occurred in 46% (any Gr) and 7% (Gr3-4) of pts; 2 treatment-related Gr 5 AEs were seen (ileus; acute respiratory failure). TRAEs ≥ 5% were fatigue, decreased appetite and anemia. TRAEs leading to dose interruption or discontinuation occurred in 11% and 6% of pts, respectively. Investigator-assessed RECIST v1.1 ORR was 15% (95% CI: 9, 23), and disease control rate (ORR + SD) was 49% (95% CI: 40, 59). Additional clinical data will be reported. Conclusions: In this expanded access study, atezo was administered to > 200 mUC pts. Overall, atezo was safe and tolerable, supporting its use in a wider platinum-based population. Clinical trial information: NCT02589717. [Table: see text]

Pertuzumab plus trastuzumab for HER2-positive metastatic urothelial cancer (mUC): Preliminary data from MyPathway

348

Background: Patients (pts) with mUC have few treatment options beyond the second-line setting. HER2 gene amplification has been reported in a minority of pts with UC, but there have been anecdotal reports of the activity of HER2-targeted agents. MyPathway is a multi-basket study evaluating the efficacy and safety of targeted therapies in non-indicated tumor types harboring relevant molecular alterations. We present preliminary data for pts with HER2-positive mUC receiving HER2-targeted treatment with pertuzumab + trastuzumab. Methods: MyPathway (NCT02091141) is an open-label, multicenter, phase IIA study. Pts in this subset analysis had refractory mUC with HER2 amplification or putative activating mutations by gene sequencing, FISH, or IHC. Pts received standard doses of pertuzumab + trastuzumab without chemotherapy until disease progression or unacceptable toxicity. The primary endpoint is investigator-assessed overall response rate (RECIST v1.1). Results: As of July 31, 2016, 12 pts with platinum-resistant HER2-positive mUC (HER2-amplified, n=9; HER2-mutated, n=3) have been enrolled. At a median follow-up of 5.4 (range 0.9–14.5) mos, 1 pt had complete response (CR, ongoing at 12.5 mos), 2 had partial responses (PR; duration of response, 3.7 and 5.5 mos), and 2 had stable disease (SD) for >4 mos (Table). Safety was consistent with the product labels. Conclusions: Preliminary results indicate that the combination of pertuzumab + trastuzumab has activity in previously treated HER2-amplified mUC, including a durable CR in a pt with peritoneal metastases. Accrual to MyPathway is ongoing. Clinical trial information: NCT02091141. [Table: see text]

What is the value of conducting a trial of r-tPA for the treatment of mild stroke patients?

Background The Phase IIIb, Double-Blind, Multicenter Study to Evaluate the Efficacy and Safety of Alteplase in Patients With Mild Stroke: Rapidly Improving Symptoms and Minor Neurologic Deficits (PRISMS) trial will assess r-tPA in ischemic stroke patients who present with mild deficits (i.e. mild stroke). Aims To assess PRISMS's societal value in clarifying the optimal care for patients with mild ischemic stroke. Methods A value of information (VOI) decision model was developed to compare the outcomes of mild stroke patients treated vs. not treated with r-tPA. Model inputs were derived from a subset of Third International Stroke Trial patients, a recent meta-analysis of r-tPA trials, expert opinion, and other published sources. VOI analyses were also used to assess the expected US societal value of the PRISMS trial and the expected value of reducing uncertainty in key trial estimates. Results The expected net societal value of the PRISMS trial was approximately $210 million ($160 m-$260 m), representing a six-fold return on investment. The value of reducing uncertainty in r-tPA efficacy was approximately $150 million ($100 m-$200 m), while reducing uncertainty in r-tPA safety (increased risk for symptomatic intracranial hemorrhage) did not add additional value in comparison. Conclusions Developing a better understanding of the outcomes of r-tPA treatment in patients with mild ischemic stroke will provide tremendous societal value by clarifying current uncertainty around treatment effectiveness. Enrollment in the PRISMS trial for patients presenting with mild ischemic stroke within 0-3 h of symptom onset should be highly encouraged.

Abstract WP284: Regional Disparities in the Quality of Stroke Care

Background: Geographic variation in healthcare quality, including an urban-rural difference, is well recognized. For stroke care, we were interested in the relationship with stroke center certification and access to neurological services.

Hypothesis: We assessed the hypothesis that the use of thrombolytic therapy (t-PA) is associated with stroke certification level and access to neurological services.

Methods: Performance measure data in the 2015 Hospital Compare, a CMS quality reporting system, were used to document the gap in care quality among hospitals according to large, medium, small-metro, and non-metro areas and Joint Commission (JC) certification. Regression analysis was used to estimate the association between t-PA use and certification level or access to neurological services.

Results: On average, non-metro hospitals performed worse than metro hospitals on JC-endorsed stroke quality measures; the biggest disparity was in the use of t-PA for eligible patients arriving within 2 hours (STK-4). Certified stroke centers in every geographic designation provided higher quality of care; however, a large variation was observed among non-certified hospitals (Figure). Regression analysis suggested that improvements in certification or access were associated with 45% and 21% absolute improvements, respectively, in the percent of patients receiving t-PA (Table).

Conclusion: The large quality gap in stroke care between metro and non-metro areas can, in part, be addressed by approaches to achieve stroke center certification or to adopt decision support systems such as telemedicine.

Abstract TP72: The PRISMS Trial: Baseline Characteristics of the First 100 Subjects

Introduction: Ischemic stroke patients with mild deficits were largely excluded from pivotal trials of IV rt-PA. The balance of benefit versus risk of intravenous thrombolysis for this large, understudied patient cohort is uncertain. The PRISMS trial is underway to test the benefit of IV rt-PA for treatment of mild stroke.

Objective: To characterize baseline features of the first 100 patients enrolled in this prospective cohort of exclusively mild stroke.

Methods: The PRISMS trial is a Phase 3b, double-blind, 75-center, 948-subject study evaluating IV rt-PA administered within three hours of mild stroke onset to improve 90-day functional outcome (modified Rankin Scale 0 or 1). Mild stroke is defined as NIHSS ≤5 and not “clearly disabling” (i.e., inability to return to work or perform basic activities of daily living based on current deficits). Patients are randomized 1:1 to IV rt-PA 0.9 mg/kg with aspirin placebo or IV rt-PA placebo with aspirin 325 mg. Here we describe baseline characteristics, including clinical presentations by NIHSS item, of the first 100 enrolled patients. The study team remains fully blinded to patient treatment assignment and outcomes.

Results: The 100th subject was enrolled on June 15, 2015. Baseline characteristics are presented in the Table. Median NIHSS was 2 (IQR 1-3). Clinical presentations of each patient by abnormal NIHSS items are shown in the Figure. Dysarthria, facial palsy, and sensory loss were the most common deficits.

Conclusions: This initial 100-patient PRISMS cohort is consistent with expectations. Upon completion, the PRISMS trial will determine the benefit of IV rt-PA for mild stroke.

Quality adjusted life year gains associated with administration of recombinant tissue-type plasminogen activator for treatment of acute ischemic stroke: 1998-2011

BACKGROUND

Intravenous recombinant tissue-type plasminogen activator (r-tPA) is an approved treatment for select patients with acute ischemic stroke (AIS). Data indicate r-tPA improves functional outcome three months after AIS compared with placebo. This study models the increase in quality adjusted life years (QALYs) associated with r-tPA compared with similar patients not treated with r-tPA.

METHODS

Hospital discharge data for AIS and r-tPA were obtained from the Nationwide Inpatient Sample from 1998 to 2011. Discharge location (home, rehabilitation, long-term care, death) was mapped to modified Rankin Scale (mRS) scores based on National Institute of Neurological Disorders and Stroke (NINDS) Study Group Part 1 and 2 clinical studies. The mRS scores were mapped to relative risk of death and QALYs obtained from the literature. The model estimated expected survival and QALYs by age, gender and mRS for patients receiving r-tPA. Life expectancy and QALYs for patients not receiving r-tPA were estimated based on discharge location and mRS for placebo patients in the NINDS study.

RESULTS

AIS discharges declined from over 635,000 in 1998 to over 593,000 in 2011. A total of 183,235 patients received r-tPA. Utilization of r-tPA increased from 1% of AIS patients in 1998 to over 4% in 2011. Estimated projections for QALYs gained from utilization of r-tPA to QALYS without r-tPA were just under 240,000 for the 13 years and with no discounting, and just over 165,000 assuming 3% annual discounting. In the most conservative scenario, assuming no difference in proportional discharge status (i.e. patients not treated with r-tPA are discharged in the same manner as r-tPA patients), the estimated life years gained are approximately 35,000 and QALYS gained are approximately 90,000.

CONCLUSIONS

r-tPA for AIS has resulted in estimated gains in quality-adjusted life years due to reduction in disability and improvement in functioning since its introduction in 1998.

Abstract 12: Do “Drip and Ship” Cases Incur Higher Costs to Warrant CMS MS-DRG Reassignment?

Background: Telestroke networks enable acute stroke patients to receive r-tPA at a remote hospital (ie, spoke) emergency department and are subsequently transferred to another hospital (ie, hub) for additional care - commonly referred to as “drip and ship” (D&S). While hub hospitals do not administer r-tPA in D&S cases, they handle all subsequent care for these patients upon arrival. It is hypothesized that current CMS reimbursement rates do not reflect the higher cost to hospitals that receive D&S patients.

Objective: Compare hospital costs and reimbursement rates for Medicare patients with AIS who received r-tPA, did not receive r-tPA, and were treated and sent to hub hospitals.

Methods: The study included Medicare-covered patients hospitalized with a primary diagnosis of AIS (ICD-9 codes 433.x1, 434.x1, 436) admitted between 6/9/2007 and 12/30/2012 from 5 hub hospitals in the Premier research database with telestroke implementation ranging from 10/2009 - 12/2011. Treatment arms were defined as r-tPA (billing data), D&S (ICD-9 =V45.88), or none. Costs were reported from the hospital perspective and compared with CMS reimbursements based on MS-DRG assignment. Median costs were compared using the Wilcoxon ranked sum test.

Results: 4122 patients were included in the study, with 84 (2%) receiving r-tPA treatment and 233 (6%) having D&S treatment. Total costs and reimbursement rates are summarized in Table 1.

Conclusions: Results from the study demonstrate D&S cases were associated with higher costs than untreated cases, despite not administering r-tPA; however, they were reimbursed similarly. Future reassignment of MS-DRG to these cases may be warranted.

Cost-Effectiveness of Recombinant Tissue-Type Plasminogen Activator Within 3 Hours of Acute Ischemic Stroke

Background and Purpose—

Despite the availability of results from multiple newer clinical trials and changing healthcare costs, the cost-effectiveness of recombinant tissue-type plasminogen activator (r-tPA) for treatment of acute ischemic stroke within 0 to 3 hours of symptom onset was last evaluated in 1998 for the United States Using current evidence, we evaluate the long-term cost-effectiveness of r-tPA administered 0 to 3 hours after acute ischemic stroke onset versus no r-tPA.

Methods—

A disease-based decision model to project lifetime outcomes of patients after acute ischemic stroke by r-tPA treatment status from the US payer perspective was developed. Model inputs were derived from a recent meta-analysis of r-tPA trials, cohort studies, and health state preference studies. Cost data, inflated to 2013 dollars, were based on drug wholesale acquisition cost and the literature. To compare r-tPA to no r-tPA, we calculated incremental total direct costs, incremental quality-adjusted life years, and incremental cost-effectiveness ratios. We performed 1-way and probabilistic sensitivity analyses to evaluate uncertainty in the results.

Results—

r-tPA resulted in a gain of 0.39 quality-adjusted life years (95% confidence range, 0.16–0.66) on average per patient and a lifetime cost-saving of $25 000 (95% confidence range, −$42 500 to −$11 000) compared with no r-tPA. In probabilistic sensitivity analyses, r-tPA was dominant compared with no r-tPA in ≈100% of simulations. The model was sensitive to inputs for r-tPA efficacy, healthcare costs for disabled patients, mortality rates for disabled and nondisabled patients, and quality of life estimates.

Conclusions—

Our analysis supports earlier economic evaluations that r-tPA is a cost-effective method to treat stroke. Appropriate use of r-tPA should be prioritized nationally.

Comparison of hospital length of stay, costs, and readmissions of alteplase versus catheter replacement among patients with occluded central venous catheters

BACKGROUND

Central venous catheter (CVC) occlusion is common, affecting 30% of all CVCs.

OBJECTIVE

To compare length of stay (LOS), costs, and readmissions associated with the use of alteplase to clear catheter blockage to outcomes associated with catheter replacement.

DESIGN

Retrospective observational study utilizing a large hospital database.

PARTICIPANTS

Hospitalized patients treated for catheter occlusion from January 2006 to December 2011.

MAIN MEASURES

Univariate analyses of patient characteristics and treatment patterns and multivariable regression analyses of postocclusion hospital costs, LOS, and 30- and 90-day readmissions were conducted.

KEY RESULTS

We included 34,579 patients treated for a CVC occlusion by replacement (N=1028) or by alteplase (2 mg) administration (N=33,551). Patients receiving alteplase were somewhat younger than those having catheter replacement (60 ± 19 vs 62 ± 20 years old, P=0.0002). After adjusting for patient and hospital factors via regression modeling, average daily postocclusion costs were $317 lower for alteplase recipients than for catheter replacement patients (95% confidence interval [CI]: 238.22-392.24; P<0.0001). Adjusted total postocclusion costs were $1419 lower for alteplase recipients versus patients receiving catheter replacement (95% CI: 307.27-2458.12; P=0.0121). Postocclusion operating room/surgery, radiology, and supply costs were significantly lower for alteplase recipients (P<0.001). Average adjusted postocclusion LOS was similar for both groups (P>0.05). Odds of readmission were not significantly different at 30 or 90 days.

CONCLUSIONS

Among patients treated for an occluded CVC, alteplase-treated patients had lower daily and total postocclusion costs than patients receiving catheter replacement. Cost differences were mainly driven by lower operating room/surgery, radiology, and supplier costs.

Abstract W MP107: An Updated Cost-Effectiveness Analysis of r-tPA for Acute Ischemic Stroke Treated Within 3 Hours of Symptom Onset

Background: A recently completed meta-analysis by Wardlaw and colleagues, including the results of the IST-3 trial, provides more precise estimates of the efficacy and safety of r-tPA in the treatment of acute ischemic stroke (AIS) within 3 hours of symptom onset. No economic analyses have been conducted for r-tPA in the 0-3 hour treatment timeframe since 1998, and changing healthcare costs and better estimates of long-term disposition offer an opportunity to reassess the value of r-tPA in AIS.

Objective: To evaluate the cost-effectiveness of r-tPA within 3 hours of symptom onset compared to no r-tPA among patients with AIS using updated efficacy, safety, and healthcare cost data.

Methods: A Markov decision model compared r-tPA treatment within 3 hours of symptom onset vs. no treatment in a hypothetical cohort of r-tPA-eligible AIS patients. Key model inputs (efficacy, safety, and mortality associated with each health state parameter) were varied based on the NINDS and ECASS III clinical trials and a recent meta-analysis of all trials, including the newly published IST-3 trial. Patients with modified Rankin scores of 0-1, 2-5, and 6 were classified into health states of non-disabled, disabled, or dead, respectively. Costs and utilities (patient preferences) associated with each health state were derived from the literature. The primary outcomes were incremental quality-adjusted life years (QALYs) gained and lifetime healthcare costs from a payer perspective.

Results: Treatment with r-tPA was associated with increased QALYs between 0.14 and 0.46. The cost-effectiveness results ranged from a cost savings of $2700 to $25,000 per QALY gained in a worst-case scenario. Major drivers of results were efficacy, cost of r-tPA, disabled patient mortality, disabled patient quality of life, and risk of recurrent stroke.

Conclusion: Economic analyses based on current clinical and cost data suggest that r-tPA is highly cost effective in the treatment of AIS across numerous efficacy, safety, and mortality estimates. Further research on differences in long-term mortality in disabled and non-disabled patients will refine these estimates.

Abstract 136: Is the Use of r-tPa in Mild Stroke Patients Cost-Effective?

Background: The use of r-tPA in patients with moderate to severe stroke has been shown to be efficacious and cost-effective. However, nearly half of all ischemic strokes present with mild deficits (i.e. either persistently mild or rapidly improving stroke), and a third of untreated mild strokes result in significant disability. Small studies and post-hoc analyses of the recently completed IST-3 trial suggested r-tPA may reduce disability for mild stroke. If these preliminary clinical findings are verified, r-tPA in mild stroke patients may provide good economic value to healthcare systems.

Objective: To model the potential cost-effectiveness of r-tPA in the treatment of mild stroke in the US.

Methods: We developed a decision analytic model to simulate the outcomes of mild stroke patients treated vs. not treated with r-tPA. We modeled stroke severity health states based on modified Rankin scale (mRS) and Oxford handicap scale (OHS) scores using Markov techniques. Preliminary estimates of r-tPa effectiveness in patients suffering mild strokes were derived from a subset of IST-3 patients. Non-disabled patients were defined as having baseline NIHSS 0-15 who otherwise met all other standard three-hour r-tPA eligibility criteria. Healthcare costs, quality-adjusted life-years, and incremental cost-effectiveness were calculated, and scenario analyses were conducted to assess uncertainty.

Results: Treatment with r-tPA was estimated to lead to a 0.36 (range, 0.34 to 0.76) increase in quality-adjusted life years per patient treated, and cost-savings ranging from $871 to $5500. In widely varying scenario analyses, as long as r-tPA treatment resulted in a 2% absolute increase in the proportion of non-disabled patients, r-tPA was highly cost effective. The main drivers in the results were r-tPA effectiveness, healthcare costs for disabled patients, and quality-of-life for non-disabled patients.

Conclusion: Economic analyses based on preliminary clinical data suggest that r-tPA could be cost-saving or highly cost-effective in the treatment of mild patients. Controlled clinical trials will be valuable in definitively establishing the clinical and economic value of r-tPA in this patient population.

Abstract T MP21: Effect of IV rtPA in Mild Strokes in the Third International Stroke Trial (IST3): A Post Hoc Analysis

BACKGROUND: A relatively small number of patients with mild ischemic stroke (NIHSS 0-5) had been included in randomized trials of IV tPA up to 2012, and debate continues about the balance of risk and benefit from thrombolysis in this group. In the recent IST3 trial, among patients with NIHSS 0-5, 221/304 (72.7%) tPA vs. 232/308 (75.3%) control subjects were alive and independent (OHS 0-2) at 6 months, a nonsignificantly adverse effect. To determine whether a further trial in mild stroke patients was justified, we examined the effect of tPA in a more restricted subset of IST3 patients with NIHSS 0-5 who met NINDS tPA Study criteria.

METHODS: The IST3 trial was a pragmatic, international, randomized-controlled, open-treatment trial with broad entry criteria comparing IV tPA with control within 6 hours of onset in 3035 subjects conducted in 12 countries outside the USA. We restricted analysis to subjects with NIHSS 0-5 who were treated within three hours, had pretreatment BP<185/110, and met all other NINDS tPA Study criteria. No age restriction was applied. The primary outcome was the proportion alive and independent (OHS 0-2) at 6 months; key secondary analyses were an ordinal analysis of OHS and the proportion alive and with ‘favorable outcome’ (OHS 0-1). (Details at www.ist3.com).

RESULTS: 612 of 3035 (20.2%) subjects enrolled in the IST3 trial had an NIHSS of 0-5. 106 of 612 (17.6%) were recruited within 3 hours, had pretreatment BP<185/110, and met all NINDS tPA Study criteria. In this subset, tPA was associated with a significant increase in the proportion alive and independent, and a favorable shift in distribution of OHS grades. There was no significant effect on ‘favorable outcome’. See Table.

CONCLUSIONS: This post-hoc analysis in a highly selected sample of the IST3 trial supports the rationale of the PRISMS trial, a randomised placebo-controlled Phase III, 950-subject, 75-center, North American study to evaluate the efficacy and safety of IV tPA in mild ischemic strokes.

Abstract W P184: Comparison of Thrombolytic Treatment for Acute Ischemic Stroke Pre- and Post -Telemedicine Implementation in the Spoke Hospital Setting

Background: Stroke telemedicine enables “Hub” hospitals with stroke expertise to interact with smaller “Spoke” hospitals in an effort to improve capabilities of accurate diagnosis and treatment of patients suffering from an acute stroke event. Administration of recombinant tissue plasminogen activator (rtPA) for treatment for acute ischemic stroke (AIS) patients is time dependent, and telemedicine has the potential to increase AIS patient thrombolytic treatment rate.

Objective: To compare treatment rates of AIS patients in the Spoke hospital setting before and after implementation of telemedicine.

Methods: The study included patients (age≥18) hospitalized with a primary diagnosis of AIS (ICD-9 codes 433.x1, 434.x1, 436) admitted to the hospital between January 1, 2006 and December 30, 2012 from 13 pre-specified Spoke hospitals in the Premier research database with telemedicine implementation ranging from October 2009 through December 2011. Evidence of MRI or CT scan during the hospital stay was required for study inclusion. Treatment of rtPA was identified using ICD-9 procedure code 99.10 and/or charge master data indicating rtPA use.

Results: A total of 9,629 and 5,228 patients were included in the study population pre- and post- telemedicine implementation respectively. Mean age and gender distribution were similar for pre- and post- implementation (72.0 vs. 71.3 years; 53.1% vs. 51.9% female, respectively). The percentage of patients treated with rtPA increased from 4.4% during pre- to 6.9% during post-implementation (p <0.0001) time period, a 56.8% increase. Increase in treatment percentages were seen in hospitals with <200 beds (1.1% vs. 7.3% p<0.0001) and hospitals with >= 200 beds (5.2% vs. 6.8% p=0.0003).

Conclusions: Results from the study demonstrate that the percent of patients treated with rtPA with telemedicine increased more than 50% as compared to the pre-telemedicine time period. Smaller hospitals showed the most significant increase in rtPA treatment rate. This finding supports previous findings that telemedicine improves appropriate use of thrombolytic treatment for AIS patients and highlights the impact in smaller hospital settings.

Gene Expression Profiles and B-Type Natriuretic Peptide Elevation in Heart Transplantation

Background— B-type natriuretic peptide (BNP) is chronically elevated in heart transplantation and reflects diastolic dysfunction, cardiac allograft vasculopathy, and poor late outcome. This investigation studied peripheral gene expression signatures of elevated BNP concentrations in clinically quiescent heart transplant recipients in an effort to elucidate molecular correlates beyond hemodynamic perturbations.

Methods and Results— We performed gene microarray analysis in peripheral blood mononuclear cells of 28 heart transplant recipients with clinical quiescence (absence of dyspnea or fatigue; normal left ventricular ejection fraction [EF >55%]; ISHLT biopsy score 0 or 1A; and normal hemodynamics [RAP <7 mm Hg, PCWP ≤15 mm Hg, and CI ≥2.5 L/min per m 2 ]). BNP levels were performed using the Triage B-type Natriuretic Peptide test (Biosite Diagnostics Inc, San Diego, Calif) and median BNP concentration was 165 pg/mL. Seventy-eight probes (of 7370) mapped to 54 unique genes were significantly correlated with BNP concentrations ( P <0.001). Of these, the strongest correlated genes ( P <0.0001) were in the domains of gelsolin (actin cytoskeleton), matrix metallopeptidases (collagen degradation), platelet function, and immune activity (human leukocyte antigen system, heat shock protein, mast cell, and B-cell lineage).

Conclusions— In the clinically quiescent heart transplant recipient, an elevated BNP concentration is associated with molecular patterns that point to ongoing active cardiac structural remodeling, vascular injury, inflammation, and alloimmune processes. Thus, these findings allude to the notion that BNP elevation is not merely a hemodynamic marker but should be considered reflective of integrated processes that determine the balance between active cardiac allograft injury and repair.