Anti PD-L1 Research Articles

Activity and tolerability of maintenance avelumab immunotherapy after first line polychemotherapy including platinum in patients with locally advanced or metastatic squamous cell penile carcinoma: PULSE

Background Metastatic Squamous cell Penile Carcinoma (mSCPC) is an orphan disease with a virally induced oncogenesis. PD-L1 expression rate is around 60% with a strong correlation between PD-L1 in the primary tumour and metastases. The first line systemic treatment relies on platinum-based chemotherapies with a median progression free survival and overall survival around 7.5 and 16 months, respectively. Immunotherapies targeting PD-1/PD-L1 axis are effective in other squamous cell or HPV related cancers. Methods PULSE is a prospective multicenter open label single arm phase II study. Thirty-two patients will be enrolled after a radiological assessment showing a non-progressive disease after 3 to 6 cycles of a first line platinum-based polychemotherapy. Patients will receive Avelumab injections 10mg/ kg every two weeks until progression or unacceptable toxicity. The primary endpoint will be the progression free survival (PFS) according to RECIST v1.1 criteria. Secondary endpoints will include PFS according to iRECIST criteria, overall survival, quality of life, safety. Ancillary explorations will include assessing blood and tissue biomarkers for association with clinical benefit. Discussion After the first line, the prognosis remains poor with no consensus on a second line systemic treatment in locally advanced or mSCPC. PULSE trial is the first study that assess an anti PD-L1 immunotherapy in maintenance among patients with locally advanced or mSCPC. NCT NUMBER : NCT03774901.

Comparative quantitative safety profiles of PD-1 and PD-L1 checkpoint inhibitor monotherapies: A Bayesian model-based meta-analysis.

e15167 Background: Anti-cancer therapies with immune checkpoint inhibitors (ICIs) are associated with immune-mediated adverse events (imAEs). The objective of this study was to use a Bayesian model-based meta-analysis, to compare safety profiles of PD-1 and PD-L1 checkpoint inhibitor monotherapies. Methods: We performed an exhaustive search through PubMed and TrialTrove databases, ASCO and ESMO abstracts to identify relevant ICI safety data. A Bayesian meta-analysis (BMA) was performed for all-grade and high-grade (Grades 3-4) treatment-related AEs (trAEs) and immune-mediated AEs (imAEs). The analysis was performed for total AEs and individual AEs affecting different organs: dermatological (rash, pruritus), gastrointestinal (diarrhea, colitis), hepatic (AST, ALT), respiratory (pneumonitis), and endocrine (hyperthyroidism, hypothyroidism). Software STAN along with the brms package in R software were used for the BMA. Results: A total of 145 articles were identified, covering 30,737 patients in 153 cohorts treated with anti PD-1 and anti PD-L1 monotherapies. For total all-grade and grade 3&4 trAEs, anti PD-L1 demonstrated lower AE rates vs. anti PD-1 (65% vs. 69% and 12% vs. 16%, respectively). Results were similar for total all-grade and high-grade imAEs (19% vs. 26% and 4% vs. 7%, respectively). The analysis of all-grade individual trAEs showed that anti PD-L1 exhibited lower AE rates vs. anti PD-1 for rash (8% vs. 10.5%), pruritus (9% vs. 12%), diarrhea (8.5% vs. 11%), colitis (1.0% vs. 1.6%), AST (3.0% vs. 5.5%), ALT (3.5% vs. 5.6%), pneumonitis (3.0% vs. 3.9%), hyperthyroidism (0.8% vs. 4.0%) and hypothyroidism (6.0% vs. 8.0%). For grade 3&4 trAEs, differences between anti PD-L1 and anti PD-1 were: 0.6% vs. 1.3% for diarrhea, 0.7% vs. 1.4% for colitis, and 0.9% vs 1.6% for pneumonitis. All-grade imAEs were less frequent for anti PD-L1 vs. anti PD-1 for: rash (6.5% vs. 10%), colitis (1.0% vs. 2.0%), AST (3.5% vs. 3.9%), ALT (2.9% vs. 4.0%), pneumonitis (2.0% vs. 4.0%), hyperthyroidism (2.5% vs. 4.0%) and hypothyroidism (5.5% vs. 9.0%). Similar results were obtained for grade 3&4 imAEs incidences: rash (0.5% vs. 0.9%), diarrhea (0.5% vs. 1.5%), colitis (0.5% vs. 1.1%) and pneumonitis (0.9% vs. 1.4%). Conclusions: Significant differences in trAEs and imAEs rates were shown for anti PD-L1 vs. anti PD-1 monotherapies. Anti PD-L1 demonstrated more favorable safety profiles for total and individual AE rates. Notably, AE rates for pneumonitis and colitis were twice as high for anti PD-1 vs. anti PD-L1 therapies.

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]

Phase Ib/II open-label, randomized evaluation of 2L atezolizumab (atezo) + PEGPH20 versus control in MORPHEUS-pancreatic ductal adenocarcinoma (M-PDAC) and MORPHEUS-gastric cancer (M-GC).

4540 Background: The MORPHEUS platform consists of multiple, global, open-label, randomized Phase Ib/II trials designed to identify early efficacy signals and safety of treatment (tx) combinations across cancers. Within MORPHEUS, atezo (anti–PD-L1) was tested with PEGylated recombinant human hyaluronidase (PEGPH20), an anti–stromal and extracellular matrix modulator, in patients (pts) with metastatic (m) PDAC or advanced/mGC. Methods: In 2 separate randomized trials, eligible pts with 2L mPDAC or mGC received atezo (1200 mg IV q3w) + PEGPH20 (3 µg/kg IV on D1, 8, 15). Control tx for M-PDAC (NCT03193190) was mFOLFOX6 or gemcitabine + nab-paclitaxel. In M-GC (NCT03281369), control tx was ramucirumab + paclitaxel. Primary endpoints were ORR (investigator-assessed RECIST 1.1) and safety. Results: Pts were followed up for ≥ 18 wk in M-PDAC (data cutoff: Aug 5, 2019) and ≥ 24 wk in M-GC (data cutoff, Jul 11, 2019). In M-PDAC, 66 pts received atezo + PEGPH20 and 42 received control in both preliminary and expansion phases. Confirmed ORRs were 6.1% (95% CI: 1.7, 14.8) and 2.4% (95% CI: 0.06, 12.6), respectively. Duration of response ranged from 5.3 to 11.3 mo in tx arm and was 3.9 mo in control. Median PFS was 1.5 mo (95% CI: 1.4, 2.6) and 2.3 mo (95% CI: 1.6, 4.0), respectively. Median OS was 7.1 mo (95% CI: 4.6, 9.5) and 6.8 mo (95% CI: 5.6, 8.3). Updated survival data will be presented. Respectively, 62.2% and 59.5% of pts had Gr 3-4 AEs; Gr 5 AEs were seen in 4.5% and 2.4% of pts; serious AEs (SAEs) occurred in 45.5% and 45.2% of pts; 16.7% and 4.8% of pts had tx-related AEs leading to tx withdrawal. The most common tx-related AEs were myalgia (65.2%) and peripheral edema (28.8%) in the combination arm. In M-GC, 13 pts received atezo + PEGPH20 and 12 received control. Confirmed ORRs were 0% (95% CI: 0, 24.7) and 16.7% (95% CI: 2.1, 48.4), respectively. Gr 3-4 AEs were seen in 30.8% and 75.0% of pts, respectively. No Gr 5 AEs occurred in either arm. SAEs occurred in 7.7% and 50.0% of pts, respectively. Only 1 pt in the control arm had a tx-related AE leading to tx withdrawal. While tumor hyaluronan (HA) appears to be associated with poor prognosis in the M-PDAC control, there was no clear association between HA levels and response to atezo + PEGPH20. PK data will also be presented. Conclusions: Limited efficacy was seen with the chemotherapy-free combination of atezo + PEGPH20 in PDAC. No efficacy was seen in GC. The safety of atezo + PEGPH20 was consistent with each agent’s known safety profile; no new safety signals were identified. Clinical trial information: NCT03193190 .

Efficacy, tolerability, and biologic activity of a novel regimen of tremelimumab (T) in combination with durvalumab (D) for patients (pts) with advanced hepatocellular carcinoma (aHCC).

4508 Background: The combination of dual immune checkpoint inhibitors (ICI) T (anti–CTLA-4) and D (anti–PD-L1) showed tolerability with a promising objective response rate (ORR) in the initial cohort of this study (NCT02519348). Subsequent evaluation of pts with solid tumors treated with increasing doses of T suggested priming with a higher dose of T may induce a stronger immune response and enhance anti-tumor activity. Thus, the randomized expansion cohorts comprised 4 arms evaluating T and D as monotherapies and 2 T+D regimens, including a novel T+D regimen featuring a single, priming dose of T. Methods: ICI-naïve pts with aHCC who progressed on, were intolerant to, or refused sorafenib were randomized to one of two T+D combinations: T300+D (T 300 mg + D 1500 mg 1 dose followed by D Q4 weekly [Q4W]) or T75+D (T 75 mg Q4W + D 1500 mg Q4W [4 doses] followed by D Q4W); or single agent D (1500 mg Q4W) or T (750 mg Q4W). Safety was the primary endpoint. ORR by blinded, independent central review using RECIST v1.1, duration of response (DoR), circulating lymphocytes, and overall survival (OS) were assessed. Results: At data cut-off (09/02/2019), 332 pts were enrolled. Median follow-ups were 11.7 months (mo) for T300+D, 14.6 (T75+D), 8.9 (D), and 15.8 (T). Treatment-related adverse event (trAE) incidences are shown (Table); no deaths were attributed to trAEs for T300+D or T. The T300+D arm had the highest confirmed ORR (DoR not reached [NR]) and longest OS (Table). A unique proliferative T cell profile was identified for pts in the T300+D arm, suggesting additive biologic activity for the combination, and showed pts with an OR exhibited high cytotoxic (CD8) counts. Conclusions: The encouraging clinical activity and tolerable safety profile suggest T300+D provides the best benefit-risk profile as opposed to T75+D or monotherapies. The unique pharmacodynamic activity of the T300+D regimen further supports its use in aHCC. T300+D and D are being evaluated in the ongoing phase III HIMALAYA study (NCT03298451) in first-line HCC vs sorafenib. Funding: AstraZeneca. Clinical trial information: NCT02519348 . [Table: see text]

Patient-reported outcomes (PROs) in the randomized, phase III IMpower110 study of atezolizumab (atezo) vs chemotherapy in 1L metastatic NSCLC.

9594 Background: IMpower110 (NCT02409342) evaluated atezo (anti–PD-L1) monotherapy as 1L treatment in PD-L1–selected patients (pts) with metastatic NSCLC and met its primary endpoint with statistically significant and clinically meaningful OS benefit in TC3 or IC3 wild-type (WT; EGFR/ALK-negative) pts. PROs were prespecified endpoints to assess pt perspectives on overall clinical benefit. Methods: Pts were randomized 1:1 to receive atezo 1200 mg IV q3w (Arm A) or platinum-based chemo (Arm B; 4 or 6 21-day cycles). Arm B non-squamous pts received cisplatin (cis) 75 mg/m2 or carboplatin (carbo) AUC 6 + pemetrexed 500 mg/m2 IV q3w; Arm B squamous pts received cis 75 mg/m2 + gemcitabine (gem) 1250 mg/m2 or carbo AUC 5 + gem 1000 mg/m2 IV q3w. PROs were assessed by the EORTC Quality of Life Questionnaire Core 30 (QLQ-C30) and lung cancer module QLQ-LC13. Time to confirmed deterioration (TTD) in QLQ-LC13 lung cancer symptoms (secondary endpoint) and change from baseline (BL) in global health status (GHS), functioning and lung cancer symptoms (exploratory endpoints) were analyzed in TC3 or IC3-WT pts. Clinically meaningful change was defined as a ≥10-point deterioration from BL. Results: Completion rates at BL (atezo, n = 107; chemo, n = 98) were high in both arms for the QLC-C30 (90% atezo, 86% chemo) and the QLC-LC13 (89% atezo, 85% chemo), and remained > 80% at most visits. Mean BL scores for GHS, physical functioning, and role functioning were moderate, symptom burden was low, and all were similar in both arms. No differences in TTD were seen between arms for cough (HR, 0.98; 95% CI: 0.48, 2.03), chest pain (HR, 1.02; 95% CI: 0.47, 2.22), dyspnea (HR, 0.96, 95% CI: 0.57, 1.60), and 3-symptom composite score (HR, 0.92; 95% CI: 0.59, 1.44). Mean change in physical function from BL to wk 42 was modestly improved with atezo and greater than or similar to chemo. No clinically meaningful worsening in dyspnea, cough or chest pain was seen with atezo vs chemo. Mean change in cough and chest pain from BL numerically improved immediately after start of treatment and was maintained to wk 48 with atezo. Fatigue and nausea/vomiting scores numerically improved immediately with atezo and were maintained to wk 48. Conclusions: QLQ-C30 and QLQ-LC13 completion rates were high at BL and most study visits. TTD of lung cancer-related symptoms was similar in both arms, indicating pts’ low BL symptom burden was maintained for a similar duration. Pts receiving atezo vs chemo sustained numerical improvements in physical function and no worsening in lung cancer-related symptoms. Clinical trial information: NCT02409342 .

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 .

Immortal time bias in the association between toxicity and response for immune checkpoint inhibitors: A systematic review and meta-analysis.

e15080 Background: A number of studies have addressed the association between Immune related Adverse Events (IrAE) and outcome in patients treated with Immune Checkpoint Inhibitors (ICI). Only a minority of them considered the effect of immortal time bias (ITB), and results of these papers are conflicting. The aim of our meta-analysis was to assess the relationship between IrAE and outcomes for patients treated with ICIs, with a focus on ITB in weighing the role of this association. Methods: PubMed, Embase (Ovid), and Scopus were searched through January 2, 2020. Studies reporting the prognostic impact of IrAE development on outcome in advanced cancer patients treated with anti PD-1 or PD-L1.Two investigators independently extracted data from each study following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guideline. Author name, cancer type, PD-1 and PD-L1 inhibitor used, number of patients, number and type of all adverse events, presence of a landmark analysis, median OS and PFS and difference between patient with or without IrAE in terms of OS and PFS (Hazard Ratio) and ORR (Odds Ratio) were extracted. Data were pooled using a random-effects model. Main outcome were Overall Survival (OS), Progression Free Survival (PFS) and Overall Response Rate (ORR). Analysis was performed with dedicated software (R studio version 1.2.1335, metafor package). Results: A total of 29 articles comprising 7430 patients were included. 7 papers published the results of survival analysis according to landmark analysis, 2 papers published only the naïve analysis while stating that a landmark analysis resulted non significant, and the others did not perform a landmark analysis. IrAEs were associated with improved outcomes with high heterogeneity ( I2 70.8%, p < 0.001 for OS; 65.7%, p 0.002 for PFS; 62.1%, p 0.001 for ORR). When subgroup analysis was performed according to the adoption of a landmark approach, the association between IrAE and outcome remains significant for OS, PFS and ORR but the effect size was smaller ( HR 0.61 vs 0.41 for OS, ANOVA Q-test for difference between subgroup p = 0.015; HR 0.66 vs 0.47 for PFS, ANOVA Q-test p 0.029; OR 2.59 vs 6.77 for ORR, ANOVA Q-test p < 0.001) while heterogeneity was substantially reduced (I2 for papers using LM 43% for OS, p 0.115; 9.7% for PFS, p 0.355; 0.0% for ORR, p 0.556). Conclusions: Our analysis suggests a significant confounding effect of ITB as well as a real effect of IrAE development on outcome.

Association of baseline characteristics and survival in patients with advanced non-small cell lung cancer (NSCLC) treated with immune checkpoint inhibitors (CPIs): Real-world evidence.

e21625 Background: CPIs including antibodies to programmed death-1 (PD-1) and its ligand anti PD-L1 are associated with superior overall survival (OS) in NSCLC. PDL1 is an imperfect predictive biomarker. We have examined real world data to identify additional factors associated with clinical benefit. Methods: 96 consecutive NSCLC patients (pts) were treated with CPIs at our institution. Multivariate cox proportional hazard regression models were used to examine the associations between OS and baseline characteristics including age, sex, histology, PDL1 status, performance status (PS), steroid use and brain metastases. Results: 93% (89/96) of pts received pembroluzimab, 6 (6%) nivolumab, and 1 (1%) atezoluzimab. All pts had metastatic disease (68% adenocarcinoma). 15% had PS 0, and 70% PS1. 11 of the 96 pts had brain metastases prior to CPI, 4 (37%) had whole brain radiotherapy, 2 (18%) targeted radiotherapy, 2 (18%) resection with radiotherapy and 3 (27%) had no definitive treatment for brain metastases. After multivariate analysis those with PS 1-2 had an increased risk of death (PS = 1 HR 2.74, 95% CI 1.11-6.72; PS = 2 3.61, 95% CI 1.28-10.15) compared with PS 0. Outcomes for pts receiving corticosteroids at the time of initiation of CPI were also inferior (HR 2.29, 95% CI 1.10-4.74) compared to those who were not. Conversely those who had brain metastasis diagnosed prior to commencing CPI had superior OS (HR 0.29 95% CI: 0.11-0.76). No statistically significant association was seen with age, gender, histology, stage at diagnosis, smoking or mutational status. PDL < 50% compared to > 50% was associated with an increased risk of death (HR 1.53 95% CI: 0.90-2.60) though it was not statistically significant. Conclusions: Here we show, using real world data, that PS and use at baseline of oral corticosteroids are associated with inferior OS with CPI treatment for NSCLC, in line with reports from large clinical trials. We show that baseline brain metastases are associated with improved outcomes. This may be explained by survivor bias, in that those who are successfully treated for brain disease, remain PS ≤2 and are able to commence CPI represent a highly selected group.

Phase III randomized study of adjuvant treatment with the ANTI-PD-L1 antibody avelumab for high-risk triple negative breast cancer patients: The A-BRAVE trial.

TPS598 Background: Chemotherapy represents, today, the only treatment option for triple negative breast cancer (TNBC) and still a considerable proportion of pts with primary TNBC experience disease relapse. The risk is particularly high in the presence of poor prognostic features, such as more advanced stage and, for pts treated with neoadjuvant chemotherapy, failure to achieve a pCR. Recent evidence suggest that immunotherapy can play a major role in TNBC pts. Methods: The A-BRAVE trial is an investigator-driven trial sponsored by the University of Padova (Dept. of Surgery, Oncology and Gastroenterology). This is a phase III, multicentric, randomized adjuvant study that compares 1 year of treatment with the anti PD-L1 avelumab vs observation for pts who completed treatment with radical intent for primary TNBC including surgery and chemotherapy. The study enrolls pts in two strata: -Stratum A: primary TNBC pts who completed surgery followed by adjuvant, defined according to one of the following stage categories: if pN2, any pT; if pN1, pT > 2 cm; if pN0, pT > 5 cm. -Stratum B: primary TNBC pts who completed neoadjuvant chemotherapy followed by surgery who did not achieve pCR. Pts who also received additional adjuvant chemotherapy for no more than 6 months are eligible in Stratum B, after the completion of the adjuvant chemotherapy. Pts are randomized (1:1, balanced for strata A and B) to receive Avelumab 10 mg/kg I.V. q2w for 1 year or to observation. The first and second co-primary endpoints are disease-free survival (DFS) in all pts and DFS in Stratum B pts. With a planned sample size of n = 474 pts the trial has 90% power to detect a HR = 0.60 for the first co-primary endpoint (n = 172 events required). Taking into account that the percentage of patients enrolled in the stratum B could range from 70 to 80%, there will be 70-79% power to detect a HR = 0.60 at alpha allocated in this patient subgroup (second co-primary endpoint). Secondary objectives include: DFS in PD-L1 positive pts, overall survival, safety, biomarkers. Tumor tissue, plasma samples and fecal samples are collected for biomarker analysis. The study is currently recruiting across 73 sites in Italy and UK. As of February 2020, n = 349 pts have been enrolled. EUDRACT 2016‐000189‐45. The authors present the A-BRAVE trial in progress on behalf of Italian and UK investigators. Clinical trial information: NCT02926196 .

Phase Ib study assessing different sequencing regimens of atezolizumab (anti-PD-L1) and sipuleucel-T (SipT)in patients who have asymptomatic or minimally symptomatic metastatic castrate resistant prostate cancer.

e17564 Background: Combining an immune checkpoint inhibitor with a tumor vaccine may leverage complementary mechanisms of action for treatment of mCRPC. Atezolizumab, a fully human anti–PD-L1 IgG1 antibody, is an approved treatment option in multiple indications; while SipT, an autologous cellular immunotherapeutic, is approved for treatment of metastatic castrate resistant prostate cancer (mCRPC). We present a phase Ib study evaluating safety, tolerability and objective response rate of atezolizumab + SipT in patients with mCRPC (NCT03024216). Methods: Eligible patients who had asymptomatic or minimally symptomatic progressive mCRPC and met standard criteria for sipuleucel-T were randomized to receive either atezolizumab 1200 mg IV every 3 weeks for 2 doses then SipT IV every 2 weeks for a total of three infusions (Arm 1) or SipT IV every 2 weeks for a total of three infusions followed by atezolizumab 1200 mg IV every 3 weeks for 2 doses (Arm 2). The primary endpoint was safety, while secondary endpoints included objective tumor response (PCWG2 and modified RECISTv1.1 criteria) and comparing systemic immune responses after induction between the arms. Results: As of February 6, 2020, 37 pts (median follow-up 7.4 months, median age 75 yrs [range 53.0–86.0]; median number of previous treatments 4 [range 1-8], 75.7% ECOG PS = 0) were enrolled. Three patients did not complete induction therapy (1 – withdrew consent, 1 developed toxicity, and 1 progressed). There were no grade 5 toxicities attributed to study drugs and grade 4 toxicities were noted in 2 patients, 1 in each arm (Arm 1 bronchitis and Arm 2 hypotension). Eight grade 3 toxicities were noted in arm 1 (hyponatremia, pulmonary embolus x3, bone pain, hypophosphatemia, shock, tooth fracture from a fall), while 4 grade 3 toxicities were noted in arm 2 (anemia, hypertension x 2, pneumonia). None of the grade 3 or 4 SAEs were noted to be irAEs. At 6 months, there were 11 SD (7 in Arm 1 and 4 in Arm 2), 18 PD and 7 unevaluable (3 withdrew from study and 4 have yet to reach 6 month evaluation). At this time, PFS was noted to be 8.2 months in Arm 1 and 5.8 months in Arm 2 (p = 0.054). Conclusions: The safety profile of the combination of atezolizumab with sipuleucel-T appears manageable in a heavily pre-treated population and consistent with those agents administered as monotherapy. Responses were seen but no CR. Immune activation studies may shed light on which sequence is optimal. Clinical trial information: NCT03024216 .

Immunofocus-PD-L1 high throughput quantitative next generation sequencing assay.

e13521 Background: Immunohistochemical (IHC) assays are presently used as the gold standard predictive tests for immunotherapy but are compromised due to a number of potential variables. Comparative studies have demonstrated differing levels of PD-L1 staining between assays which appears independent of the antibody binding epitope. Secondly, inter-reader reliability even between expert pathologists is problematic particularly for assessment of PD-L1 positive immune cell populations. Methods: To improve predictive testing for anti PD-L1/PD1 immunotherapies we have developed and validated a Next Generation Sequencing Platform, Immunofocus, able to perform high-throughput quantitative PD-L1 gene expression levels in routine diagnostic PWET biopsies. We applied Immunofocus to a cohort of 130 NSCLCs and compared PD-L1 gene expression levels with PD-L1 IHC scores generated using the VENTANA PD-L1 (SP142) Assay. The PD-L1 IHC assessment was carried out double blinded by an independent laboratory. PD-L1 IHC scores were calculated using an algorithm combining tumour proportion score (TPS) with a PD-L1 positive immune cell (IC) score and immune cell area. Results: An exceptionally high degree of correlation was observed between the NGS PD-L1 levels with the combined PD-L1 IHC scores (P < 0.001). Therapeutic cut points for NGS PD-L1 levels were identified corresponding to PD-L1 IHC defined clinical cut points. Notably, ~20% of patients with negative PD-L1 IHC scores showed high NGS PD-L1 expression levels. We hypothesize that these cases represent false negatives and identify a cohort of patients who have shown significant response rates to anti-PD-L1/PD-directed immunotherapies. Conclusions: The Immunofocus NGS PD-L1 assay has potential to greatly improve patient selection for immunotherapy by removing the IHC assay variables and inter-reader variability which compromise current PD-L1 IHC tests while also providing standardized high throughput in the clinical setting. Immunofocus is able to integrate gene expression with somatic mutation analysis allowing capture of networks regulating the immune-checkpoint including for example adaptive and innate resistance pathways, JAK1/2 pathways, differential MHC expression, TEFF gene signature, neoantigen surrogates such as DDR defects and TMB. The integration of NGS PD-L1 expression with other putative biomarkers of response is presently ongoing to further improve prediction of response.

Preliminary population pharmacokinetics supports phase II dose selection for masked anti-PD-L1 antibody CX-072.

3602 Background: PROBODY therapeutics (Pb-Tx) are antibody prodrugs designed to reduce off-tumor, on-target toxicities. The mask inhibits Pb-Tx binding in the periphery yet can be removed by tumor-associated proteases, restricting target engagement to the tumor. This is the first report of preliminary clinical pharmacokinetic (PK) analysis supporting selection of the phase II dose for CX-072, an anti–PD-L1 Pb-Tx, from the ongoing phase I/II PROCLAIM-CX-072 study (NCT03013491). Methods: A quantitative systems pharmacology (QSP) model1 was used to project the CX-072 plasma trough level (Cmin) corresponding to 95% intratumoral receptor occupancy (RO). Human PK and anti-drug antibody (ADA) data were obtained at selected times postdose following IV administration of 0.03–30 mpk CX-072 in PROCLAIM-CX-072. Population PK (POPPK) modeling was performed with NONMEM v7.3.0. Exploratory analysis and simulations were done with R v3.3.1 or later. Covariates were selected for POPPK using forward addition ( P<0.05) followed by backward deletion ( P<0.01). Results: The preliminary POPPK analyses were informed using available PK data as of August, 2019 from 135 subjects receiving CX-072 Q2W as monotherapy in the dose-escalation and expansion cohorts of PROCLAIM-CX-072. A mixture model was used to capture time- and dose-dependent apparent ADA effect on clearance (CL). The preliminary POPPK model estimates for CX-072 CL and volume of distribution (Vd) were 0.306 L/day and 4.84 L, respectively. Statistically significant covariate effects included body weight on the central Vd and CL, and albumin on CL. The QSP model predicted a CX-072 Cmin of 13–99 nM would be required for 95% intratumoral RO. POPPK simulations suggested that >95% of patients receiving CX-072 10 mg/kg Q2W would meet or exceed this targeted Cmin regardless of ADA. Additional observed data indicated that the majority of patients receiving 10 mpk CX-072 Q3W × 4 with 3 mpk ipilimumab (IPI) Q3W × 4 in the CX-072-IPI combination part of PROCLAIM-CX-072 maintained the targeted Cmin. Simulations did not suggest there would be a clinically meaningful change in exposure following a fixed dose of CX-072 800 mg relative to the 10 mpk weight-based dose. Conclusions: Preliminary PK analysis supports selection of 800 mg CX-072 Q2W as the recommended monotherapy dose and 800 mg Q3W when combined with IPI. The combination of 800 mg CX-072 + 3 mpk IPI Q3W × 4 doses, followed by monotherapy administration of 800 mg CX-072 Q2W is being further explored in phase II. Reference: 1) Stroh M et al. CPT. 2019(9):676-84. Clinical trial information: NCT03013491 .

Real-world clinical outcomes in avelumab-treated patients (pts) in the United States (U.S.) from SPEAR-Merkel –Study informing treatment Pathway dEcisions in Merkel cell cARcinoma (MCC).

e22029 Background: MCC is a rare, aggressive disease associated with poor prognosis. Avelumab, a fully human anti–PD-L1 monoclonal antibody, was the first immune checkpoint inhibitor approved by the FDA for the treatment of metastatic MCC (mMCC). In the JAVELIN Merkel 200 trial (Clinical trial information: NCT02155647), avelumab resulted in durable responses and a high objective response rate (ORR) in pts with mMCC. This retrospective descriptive study assessed real-world clinical outcomes in avelumab-treated pts with locally advanced MCC (laMCC) and mMCC in a US community oncology setting. Methods: This study included data on avelumab-treated laMCC and mMCC pts from 1/1/17 to 3/31/19 within The US Oncology Network. Study data were captured through 9/30/19 using structured fields and chart review of iKnowMed electronic healthcare records. Real-world ORR was assessed. Duration of response (DOR), progression-free survival (PFS), and overall survival (OS) were estimated using the Kaplan-Meier method. Results: 33 pts initiated treatment with avelumab (laMCC n = 11; mMCC n = 22) and were followed up for a median of 10.9 months (range, 0.5-27.2 months). Median age was 77 years (range, 44-90+ years), 78.8% of pts were male, and the majority (84.8%) of pts were treated in the first-line setting. During treatment, 27.2% of pts had emergency department visits and 39.4% were hospitalized; 1% and 23.1%, respectively, were treatment related. Clinical outcomes are reported in the table. Conclusions: This is the first study to examine pts with laMCC treated with avelumab in a real-world setting. Although the sample population is small, results suggest the clinical benefits in the real world in pts with mMCC treated with avelumab are consistent with benefits reported in the JAVELIN Merkel 200 trial. Clinical trial information: NCT02155647 . [Table: see text]

Phase I/II study to evaluate systemic durvalumab + intraperitoneal (IP) ONCOS-102 in patients with peritoneal disease who have epithelial ovarian (OC) or metastatic colorectal cancer (CRC): Interim phase I clinical and translational results.

3017 Background: Metastasis to the peritoneal cavity is associated with end-stage disease in many cancers, including OC and CRC, both of which exhibit poor responses to checkpoint inhibitors. Locoregional treatment with oncolytic viruses may be used to improve the efficacy of checkpoint inhibitors at both treated and distant tumor sites. This study evaluates the combination of IP-administered ONCOS-102, an oncolytic adenovirus encoding for granulocyte macrophage colony stimulating factor (GMCSF), with systemic durvalumab, an anti PD-L1 antibody, in patients with peritoneal disease who have histologically confirmed OC or metastatic CRC and have failed prior standard therapies. Methods: This ongoing Phase 1/2, open-label study (NCT02963831) evaluates safety and antitumor/biologic activity of durvalumab (1500 mg IV, every 4 weeks x 12) + ONCOS-102 (IP, weekly x 6); cyclophosphamide is given pre first ONCOS-102 dose. Phase 1 uses a 3+3 design to evaluate the ONCOS-102 dose (1 or 3 x 1011 VP) to be given with durvalumab. Phase 2 evaluates the activity of the combination using Simon’s 2-stage MINIMAX design. Safety, response rate by RECIST 1.1, and immunological effects in tumors were evaluated for Phase 1; the current abstract reports on the phase 1 results. Results: Enrollment opened 7 Sep 2017; data cutoff, 1 Nov 2019. There were 17 patients treated in Phase 1: 8 CRC, 9 ovarian; 94% female; median age, 56 [37-77] years; ECOG PS0, 47%; ECOG PS1, 53%. There were no DLTs. Grade 3 treatment-related AEs included hypokalemia (n = 2); anemia, myocarditis, increased GGT, and influenza like illness (n = 1 each). There were 4 deaths due to PD. One patient had durable confirmed partial response and remains on treatment > 1 year; 4 patients had stable disease as best overall response. Two patients remained on treatment at data cutoff. Analysis of pre- and on-treatment tumor biopsies revealed changes in the tumor-infiltrating immune cells and PD-L1 expression, including an increase in tumor-infiltrating CD8 T cells in 5 of 11 evaluable patients. Conclusions: Combination of durvalumab and IP ONCOS-102 was safe, and no DLTs were observed. Preliminary analyses demonstrate evidence of biologic and clinical activity. Phase 2 enrollment is ongoing. Clinical trial information: NCT02963831 .

Polygenic risk for skin autoimmunity impacts immune checkpoint blockade in bladder cancer

PD-1 and PD-L1 act to restrict T cell responses in cancer and contribute to self-tolerance. Consistent with this role, PD-1 checkpoint inhibitors have been associated with immune-related adverse events (irAEs), immune toxicities thought to be autoimmune in origin. Analyses of dermatological irAEs have identified an association with improved overall survival (OS) following anti-PD-(L)1 therapy, but the factors that contribute to this relationship are poorly understood. We collected germline whole-genome sequencing data from IMvigor211, a recent phase 3 randomized controlled trial comparing atezolizumab (anti-PD-L1) monotherapy to chemotherapy in bladder cancer. We found that high vitiligo, high psoriasis, and low atopic dermatitis polygenic risk scores (PRSs) were associated with longer OS under anti-PD-L1 monotherapy as compared to chemotherapy, reflecting the Th17 polarization of these diseases. PRSs were not correlated with tumor mutation burden, PD-L1 immunohistochemistry, nor T-effector gene signatures. Shared genetic factors impact risk for dermatological autoimmunity and anti-PD-L1 monotherapy in bladder cancer.

Targeting pulmonary tumor microenvironment with CXCR4-inhibiting nanocomplex to enhance anti-PD-L1 immunotherapy.

Anti-programmed cell death 1 ligand 1 (PD-L1) therapy is extraordinarily effective in select patients with cancer. However, insufficient lymphocytic infiltration, weak T cell-induced inflammation, and immunosuppressive cell accumulation in the tumor microenvironment (TME) may greatly diminish the efficacy. Here, we report development of the FX@HP nanocomplex composed of fluorinated polymerized CXCR4 antagonism (FX) and paclitaxel-loaded human serum albumin (HP) for pulmonary delivery of anti-PD-L1 small interfering RNA (siPD-L1) to treat orthotopic lung tumors. FX@HP induced T cell infiltration, increased expression of calreticulin on tumor cells, and reduced the myeloid-derived suppressor cells/regulatory T cells in the TME, thereby acting synergistically with siPD-L1 for effective immunotherapy. Our work suggests that the CXCR4-inhibiting nanocomplex decreases tumor fibrosis, facilitates T cell infiltration and relieves immunosuppression to modulate the immune process to improve the objective response rate of anti-PD-L1 immunotherapy.

Interferon regulatory factor 1 (IRF-1) and IRF-2 regulate PD-L1 expression in hepatocellular carcinoma (HCC) cells.

The objective response rate of immune checkpoint blockade (ICB) in hepatocellular carcinoma (HCC) with anti PD-L1/PD-1 therapy is low. Discovering the signaling pathways regulating PD-L1 might help to improve ICB response rates. Here, we investigate transcription factors IRF-1 and IRF-2 signaling pathways regulating PD-L1 in HCC cells. In vivo studies show that IRF-1 and PD-L1 mRNA expression in human HCC tumors are significantly repressed compared with noncancerous background liver. IRF-1, IRF-2, and PD-L1 mRNA expression correlated positively in HCC tumors. Increased IRF-1 mRNA expression was observed in patients with well-differentiated or early stage HCC tumors. In vitro studies show that IFN-γ induces PD-L1 mRNA and protein expression through upregulation of IRF-1 in mouse and human HCC cells. IRF-1, IRF-2, and PD-L1 mRNA expression is upregulated in murine HCC by co-culture with effector T cells from spleen cells incubated with anti-CD3/CD28 antibodies. IRF-2 over-expression down-regulates IFN-γ induced PD-L1 promoter activity and protein levels in a dose-dependent manner. We identify two IRF-1 response elements (IRE1/IRE2) in the upstream 5'-flanking region of the CD274 (PD-L1) gene promoter. Site-directed mutagenesis shows both IRE1 and IRE2 are functional in transfection promoter assays. IRF-1 traditionally functions as tumor suppressor gene. However, these novel findings show a complex role for IRF-1 which upregulates PD-L1 in the inflammatory tumor microenvironment. IRF-1 antagonizes IRF-2 for binding to the IRE promoter element in PD-L1 which gives new insight to the regulation of PD-L1/PD-1 pathways in HCC ICB therapy.

PD-L1 expression level in different thymoma stages and thymic carcinoma: a meta-analysis.

The immune checkpoint ligand, programmed cell death 1 ligand 1 (PD-L1), is expressed in various tumors and associated with response to drugs that target programmed cell death protein 1. Previous studies have estimated the level of PD-L1 expression among different stages of thymoma and thymic carcinoma to evaluate its potential use as a diagnostic factor; however, its varying expression level has been problematic. We conducted this meta-analysis of published literature to evaluate PD-L1 expression in thymomas and thymic carcinomas. We analyzed 12 studies that included 320 patients with type A/AB/B1 thymoma, 225 patients with type B2/B3 thymoma, and 180 patients with thymic carcinoma. No difference in PD-L1 expression level was found between the B2/B3 vs C groups (odds ratio [OR], 0.67; 95% confidence interval [CI], 0.26, 1.76; p = 0.42). However, the heterogeneity was very high (I2 = 78%), and a significant difference was found between groups A/AB/B1 and B2/B3 (OR, 0.22; 95% CI, 0.12, 0.41; p < 0.001), with a relatively low heterogeneity (I2 = 55%). PD-L1 positivity might be a useful factor to differentiate type A/AB/B1 thymoma from type B2/B3 and thymic carcinoma. This result might be valuable for potential anti PD-L1 treatment in thymoma and thymic carcinoma.

Depletion of tumor-associated macrophages by melittin-dKLA enhances anti PD-L1 mediated anti-tumor effects in breast cancer models

Abstract Tumor-associated macrophages (TAMs) are the most abundant immune cells in the tumor microenvironment and known to have an M2-like pro-metastatic phenotype. M2-like TAMs directly support migration, adhesion and invasion of tumor cells. Therefore, M2-like TAMs are promising targets for inhibiting cancer. Anti-PD-1/PD-L1 immunotherapies have been used for an inhibition of PD-1/PD-L1 mediated T cell exhaustion in various cancers such as lymphoma, melanoma, and renal cancer with remarkable clinical success, however, most breast cancer patients have been reported to show resistances or short response durations. A lot of researches have been reported that targeting TAMs from tumor microenvironment synergized the effect of PD-1/PD-L1 therapies, suggesting that TAMs are major causes of PD-1/PD-L1 resistance. Previously, I have developed MEL-dKLA, a hybrid peptide that was conjugated with melittin (MEL) and pro-apoptotic peptide dKLA to eliminate M2 like TAM. In this study, I investigated whether removal of M2-like TAMs by MEL-dKLA enhanced the anti-cancer effect of PD-L1 antibodies in 4T1 breast cancer. Combination therapy with MEL-dKLA and anti PD-L1 delays tumor growth and increases survival. It inhibits the exhausted CD8+ T cell population in tumors, enabling them to perform cytotoxic functions. Simultaneous treatment with MEL-dKLA and anti PD-L1 reduced the contact area between TAM and CD8+ T cells in the tumor microenvironment. Therefore, these results suggested that MEL-dKLA and anti PD-L1 combination therapy will be promising for breast cancer treatments.