Concordance Between Tissue ALK Detection by Immunohistochemistry and Plasma ALK Detection by Next-Generation Sequencing in the Randomized Phase 3 ALEX Study in Patients with Treatment-Naïve Advanced ALK-Positive NSCLC

Introduction

The Blood First Assay Screening Trial revealed the clinical applicability of blood-based next-generation sequencing to identify patients with ALK-positive NSCLC for alectinib treatment. To understand the relationship between tissue-based versus blood-based testing, we retrospectively investigated concordance between VENTANA ALK (D5F3) CDx immunohistochemistry and the FoundationACT (FACT; Foundation Medicine, Inc.) plasma assay, and compared clinical efficacy between phase 3 ALEX study subpopulations.

Methods

Patients with advanced ALK-positive (by immunohistochemistry) NSCLC were randomized 1:1 to alectinib 600 mg or crizotinib 250 mg, twice daily. Assessable baseline plasma samples were analyzed for ALK positivity by FACT; positive percent agreement with immunohistochemistry was evaluated. Progression-free survival (PFS), duration of response, and objective response rate were compared between intention-to-treat (ITT) and biomarker-evaluable populations, and plasma ALK-positive and plasma ALK-negative subpopulations.

Results

In the ITT population (303 patients; alectinib, 152; crizotinib, 151), all patients had ALK-positive tumors by immunohistochemistry. In the biomarker-evaluable population (149 patients; alectinib, 76; crizotinib, 73), 105 had plasma ALK-positive and 44 had plasma ALK-negative tumors. Positive percent agreement between immunohistochemistry and FACT was 70.5% (105 of 149; 95% confidence interval: 62.5–77.7). Baseline characteristics were generally balanced, with some exceptions, notably tumor burden. Median PFS in plasma ALK-positive and ALK-negative patients was 22.4 months and not estimable with alectinib and 7.3 months and 12.9 months with crizotinib, respectively; median duration of response was 25.9 months and not estimable with alectinib and 5.6 months and 11.5 months with crizotinib, respectively.

Conclusions

Reasonable concordance between FACT and immunohistochemistry was observed; both methods are valuable in identifying ALK-positive patients, separately or concurrently. Alectinib was found to have superior PFS in the plasma ALK-positive population, as in the ITT population.

Blood First Assay Screening Trial (BFAST) in Treatment-Naive Advanced or Metastatic NSCLC: Initial Results of the Phase 2 ALK-Positive Cohort

INTRODUCTION

The Blood First Assay Screening Trial is an ongoing open-label, multicohort study, prospectively evaluating the relationship between blood-based next-generation sequencing (NGS) detection of actionable genetic alterations and activity of targeted therapies or immunotherapy in treatment-naive advanced or metastatic NSCLC. We present data from the ALK-positive cohort.

METHODS

Patients aged more than or equal to 18 years with stage IIIB or IV NSCLC and ALK rearrangements detected by blood-based NGS using hybrid capture technology (FoundationACT) received alectinib 600 mg twice daily. Asymptomatic or treated central nervous system (CNS) metastases were permitted. Primary end point was investigator-assessed objective response rate (ORR; Response Evaluation Criteria in Solid Tumors version 1.1). Secondary end points were independent review facility-assessed ORR, duration of response, progression-free survival (PFS), overall survival, and safety. Exploratory end points were investigator-assessed ORR in patients with baseline CNS metastases and relationship between circulating biomarkers and response.

RESULTS

In total, 2219 patients were screened and blood-based NGS yielded results in 98.6% of the cases. Of these, 119 patients (5.4%) had ALK-positive disease; 87 were enrolled and received alectinib. Median follow-up was 12.6 months (range: 2.6-18.7). Confirmed ORR was 87.4% (95% confidence interval [CI]: 78.5-93.5) by investigator and 92.0% (95% CI: 84.1-96.7) by independent review facility. Investigator-confirmed 12-month duration of response was 75.9% (95% CI: 63.6-88.2). In 35 patients (40%) with baseline CNS disease, investigator-assessed ORR was 91.4% (95% CI: 76.9-98.2). Median PFS was not reached; 12-month investigator-assessed PFS was 78.4% (95% CI: 69.1-87.7). Safety data were consistent with the known tolerability profile of alectinib.

CONCLUSIONS

These results reveal the clinical application of blood-based NGS as a method to inform clinical decision-making in ALK-positive NSCLC.

Updated Overall Survival Analysis From IMpower110: Atezolizumab Versus Platinum-Based Chemotherapy in Treatment-Naive Programmed Death-Ligand 1-Selected NSCLC

INTRODUCTION

IMpower110 previously revealed significant overall survival (OS) benefit with atezolizumab versus chemotherapy in patients with treatment-naive EGFR- and ALK-negative (wild type [WT]) metastatic NSCLC with high programmed death-ligand 1 (PD-L1) expression (≥50% on tumor cells [TCs] or ≥10% on tumor-infiltrating immune cells [ICs], per SP142 immunohistochemistry assay; p = 0.0106). We present primary OS analyses in lower PD-L1 expression groups and an updated, exploratory analysis in the high PD-L1 expression group.

METHODS

This open-label, phase 3 trial randomized patients with PD-L1 expression on greater than or equal to 1% of TC or IC to receive atezolizumab or platinum-based chemotherapy. The primary end point was OS, hierarchically tested in PD-L1 expression WT subgroups: first the high PD-L1 expression subgroup, then the high-or-intermediate PD-L1 expression subgroup (≥5% on TC or IC), and then the any PD-L1 expression subgroup (≥1% on TC or IC).

RESULTS

The any PD-L1 expression WT population included 554 patients (excluded 18 EGFR- or ALK-positive patients). With 17 months' additional follow-up, OS improvement in the atezolizumab versus chemotherapy arm was not statistically significant in high-or-intermediate PD-L1 expression WT patients (n = 328; hazard ratio = 0.87, 95% confidence interval: 0.66-1.14, p = 0.3091; median = 19.9 versus 16.1 mo), precluding formal OS testing in any PD-L1 expression WT patients. Exploratory analysis in high PD-L1 expression WT patients (n = 205) revealed maintained OS benefit in the atezolizumab arm (hazard ratio = 0.76, 95% confidence interval: 0.54-1.09; median = 20.2 versus 14.7 mo). Updated safety data continued to favor atezolizumab.

CONCLUSIONS

Statistical significance for OS was not revealed in the high-or-intermediate expression WT group, and, as a result, OS in the any PD-L1 expression WT group was not formally tested. No new safety signals were found. This updated analysis of IMpower110 supports using atezolizumab in treatment-naive, metastatic WT NSCLC with high PD-L1 expression.

C-reactive protein reduction post treatment is associated with improved survival in atezolizumab (anti-PD-L1) treated non-small cell lung cancer patients

PURPOSE

Overall survival (OS) is the most significant endpoint for evaluation of treatment benefit with checkpoint inhibitors (CPI) in cancer. We evaluated serum C-reactive protein (CRP) in non-small cell lung cancer (NSCLC) trials with atezolizumab (anti-PD-L1) as an early OS surrogate.

METHODS

Serum from patients enrolled in randomized Phase II (n = 240) and Phase III (n = 701) trials of NSCLC patients (POPLAR, OAK) who progressed on prior-platinum chemotherapy, were analyzed for CRP levels over time. Patients were grouped by changes in CRP levels post-treatment as either increased (≥ 1.5 fold), decreased (≤ 1.5 fold) or unchanged (within +1.5 fold) relative to pre-treatment levels to assess association with progression free survival (PFS) and OS.

RESULTS

Decrease in serum CRP levels at 6 weeks relative to pre-treatment were observed in patients with RECIST1.1 based complete or partial responses (CR/PR) to atezolizumab whereas patients with disease progression (PD) demonstrated an increase in CRP levels in the Phase II POPLAR study, and confirmed in the Phase III OAK study. Decrease in serum CRP as early as six weeks post treatment predicted improved PFS and OS, even in patients who were determined as stable disease (SD) in their first scan. This effect was not observed in the chemotherapy arms.

CONCLUSION

Modulation of serum CRP correlates with clinical outcome post-atezolizumab treatment. This routine lab test may provide utility in informing OS signals as early as 6 weeks post-initiation of therapy with CPIs in NSCLC.

Atezolizumab for First-Line Treatment of PD-L1-Selected Patients with NSCLC

BACKGROUND

The efficacy and safety of the anti-programmed death ligand 1 (PD-L1) monoclonal antibody atezolizumab, as compared with those of platinum-based chemotherapy, as first-line treatment for patients with metastatic non-small-cell lung cancer (NSCLC) with PD-L1 expression are not known.

METHODS

We conducted a randomized, open-label, phase 3 trial involving patients with metastatic nonsquamous or squamous NSCLC who had not previously received chemotherapy and who had PD-L1 expression on at least 1% of tumor cells or at least 1% of tumor-infiltrating immune cells as assessed by the SP142 immunohistochemical assay. Patients were assigned in a 1:1 ratio to receive atezolizumab or chemotherapy. Overall survival (primary end point) was tested hierarchically according to PD-L1 expression status among patients in the intention-to-treat population whose tumors were wild-type with respect to EGFR mutations or ALK translocations. Within the population with EGFR and ALK wild-type tumors, overall survival and progression-free survival were also prospectively assessed in subgroups defined according to findings on two PD-L1 assays as well as by blood-based tumor mutational burden.

RESULTS

Overall, 572 patients were enrolled. In the subgroup of patients with EGFR and ALK wild-type tumors who had the highest expression of PD-L1 (205 patients), the median overall survival was longer by 7.1 months in the atezolizumab group than in the chemotherapy group (20.2 months vs. 13.1 months; hazard ratio for death, 0.59; P = 0.01). Among all the patients who could be evaluated for safety, adverse events occurred in 90.2% of the patients in the atezolizumab group and in 94.7% of those in the chemotherapy group; grade 3 or 4 adverse events occurred in 30.1% and 52.5% of the patients in the respective groups. Overall and progression-free survival favored atezolizumab in the subgroups with a high blood-based tumor mutational burden.

CONCLUSIONS

Atezolizumab treatment resulted in significantly longer overall survival than platinum-based chemotherapy among patients with NSCLC with high PD-L1 expression, regardless of histologic type. (Funded by F. Hoffmann-La Roche/Genentech; IMpower110 ClinicalTrials.gov number, NCT02409342.).

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 .

IMpower110: Clinical safety in a phase III study of atezolizumab (atezo) monotherapy (mono) vs platinum-based chemotherapy (chemo) in first-line non-small cell lung cancer (NSCLC)

e21623

Background: IMpower110 evaluated atezo mono in PD-L1–selected, chemo-naive patients (pts) with nonsquamous (nsq) or squamous (sq) NSCLC. At the interim analysis, IMpower110 met its primary OS endpoint, with a statistically significant and clinically meaningful improvement for atezo vs chemo in TC3 or IC3 wild-type ( EGFR/ALK-negative) pts. We report on the safety profile of atezo vs chemo in IMpower110. Methods: 572 pts with stage IV nsq or sq NSCLC, PD-L1 expression ≥ 1% on TC or IC and ECOG PS 0-1 were randomized 1:1 to receive atezo (1200 mg IV q3w) or chemo (4 or 6 21-day cycles). In the chemo arm, nsq pts received cisplatin (cis) 75 mg/m2 or carboplatin (carbo) AUC 6 + pemetrexed (pem) 500 mg/m2 IV q3w; sq pts received cis 75 mg/m2 + gemcitabine (gem) 1250 mg/m2 or carbo AUC 5 + gem 1000 mg/m2 IV q3w. Safety was assessed in all treated pts (safety evaluable [SE] population [pop]), regardless of PD-L1 expression or EGFR/ALK status. AEs were summarized per MedDRA v22.0 and severity graded per NCI CTCAE v4.0. Immune-mediated AEs (imAEs) were defined per a sponsor-specified list of terms, regardless of whether the events led to systemic glucocorticoid, endocrine therapy, or other immunosuppressants use. Results: At data cutoff (Sep 10, 2018) within the ITT pop, treatment (tx) was ongoing in 90 (atezo: 31.6%) and 25 (chemo: 8.7%) pts, with 13.7 mo of follow-up. Within the SE pop (atezo: n = 286, chemo: n = 263), atezo pts had longer tx exposure (5.3 mo) vs chemo pts (pem, 3.5 mo; gem, 2.6 mo; carbo, 2.3 mo; cis, 2.1 mo). Atezo had a favorable safety profile vs chemo (table); safety data were consistent with data from a pooled atezo mono pop. imAEs occurred in 40.2% (atezo) and 16.7% (chemo) of pts and were Grade (Gr) 3-4 in 6.6% and 1.5%, respectively. Conclusions: Atezo was better tolerated than chemo and imAEs were generally low grade. Overall, the safety experience with atezo mono in IMpower110 was consistent with its known safety profile; no new safety signals were identified. Clinical trial information: NCT02409342. [Table: see text]

O81 IMpower110: interim overall survival (OS) analysis of a phase III study of atezolizumab (ATEZO) monotherapy vs platinum-based chemotherapy (CHEMO) as first-line (1L) treatment in PD-L1–selected NSCLC

Background

PD-L1/PD-1 inhibitors (CPI) as monotherapy or in combination with platinum-based doublet chemo (± bevacizumab) are 1L treatment options in metastatic NSCLC, with choice of agent(s) determined by PD-L1 expression. For patients (pts) who may be ineligible for combination therapy, CPI monotherapy remains an attractive treatment choice. IMpower110 evaluated atezo as 1L treatment in PD-L1–selected pts independent of tumor histology.

Methods

IMpower110 enrolled 572 chemo-naive pts with stage IV nonsquamous (nsq) or squamous (sq) NSCLC, PD-L1 expression ≥ 1% on TC or IC, measurable disease by RECIST 1.1 and ECOG PS 0-1. 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 nsq pts received cisplatin (cis) 75 mg/m2 or carboplatin (carbo) AUC 6 + pemetrexed 500 mg/m2 IV q3w; Arm B sq pts received cis 75 mg/m2 + gemcitabine (gem) 1250 mg/m2 or carbo AUC 5 + gem 1000 mg/m2 IV q3w. Stratification factors were sex, ECOG PS, histology and tumor PD-L1 status (TC1/2/3 and any IC vs TC0 and IC1/2/3). The primary endpoint of OS is tested hierarchically in the wild-type (WT; EGFR/ALK-negative) population (TC3 or IC3 then TC2/3 or IC2/3 then TC1/2/3 or IC1/2/3).

Results

The 3 primary efficacy populations included 554 TC1/2/3 or IC1/2/3 WT pts, 328 TC2/3 or IC2/3 WT pts and 205 TC3 or IC3 WT pts. Median follow-up was 15.7 months (range, 0-35) in TC3 or IC3 WT pts. In the TC3 or IC3 WT population, atezo monotherapy improved median OS by 7.1 months (HR, 0.595; P = 0.0106) compared with chemo (table 1). The safety population comprised 286 pts in Arm A and 263 in Arm B. Treatment-related AEs (TRAEs) and Grade 3-4 TRAEs occurred in 60.5% (Arm A) and 85.2% (Arm B), and 12.9% (Arm A) and 44.1% (Arm B), respectively.

Abstract 081 Table 1

Conclusions

At this interim analysis, IMpower110 met the primary endpoint of OS with statistically significant and clinically meaningful improvement in the TC3 or IC3 WT population. The safety profile favored Arm A, with no new or unexpected safety signals identified.

Trial Registration

NCT02409342

Ethics Approval

The trial was conducted according to the principles of the Declaration of Helsinki. All patients provided written informed consent. Protocol approval was obtained from independent review boards or ethics committees at each site.

Abstract 5707: On-treatment changes in CRP as a surrogate for overall survival for atezolizumab benefit in 2nd line NSCLC

Background: Overall survival (OS) is an optimal endpoint for evaluation of checkpoint inhibitors (CPI). Identification of early surrogates of OS is important to inform early clinical signals and treatment decisions. We evaluated C-reactive protein (CRP) in clinical trials with atezolizumab (anti-PD-L1 antibody). CRP is elevated in different inflammatory and malignant conditions and is often considered to be a marker of poor prognosis.

Materials and Methods: Serum from patients enrolled in the 2L+ NSCLC studies POPLAR and OAK (randomized phase 2 and phase 3 controlled trials of patients with non-small cell lung cancer (NSCLC) who progressed on post-platinum chemotherapy) was analyzed for CRP levels over time. Patients were binned by changes in CRP at 6 weeks post-treatment (C3D1; Cycle 3 Day 1) as compared to pre-treatment levels, by either greater than 1.5 fold, less than 1.5 fold or unchanged (within +1.5 fold).

Results: C3D1 decreases in serum CRP were associated with RECIST1.1 based responses to atezolizumab but not with docetaxel in the POPLAR study, and these findings were further validated in the OAK study. Patients with RECIST based disease progression (PD) demonstrated an increase in serum CRP as early as Cycle 2 (3 weeks post atezolizumab therapy). Notably, decrease in CRP levels was strongly associated with improved PFS and OS. Results from OAK are shown below (table). Furthermore, in patients with RECIST PD or stable disease (SD), decrease in on-treatment CRP also predicted long overall survival.

Conclusion: CRP is a soluble biomarker that is modulated post-atezolizumab treatment. This simple lab test may provide utility in informing OS benefit for CPIs and combinations.

C3D1 CRP fold change relative to pre-treatmentHRCIp valueHRCIp valueITT0.750.62-0.910.0040.740.6-0.910.0053CRP <1.5 FC0.480.33-0.690.0000950.490.32-0.750.0011CRP +1.5 FC0.850.62-1.150.280.610.43-0.860.0049CRP>=1.5 FC0.960.69-1.340.811.250.86-1.810.25

Citation Format: Namrata Patil, Wei Zou, Simonetta Mocci, Vinita Gupta, Luciana Molinero, Alan Sandler, Marcus Ballinger, Susan Flynn, Marcin Kowanetz, Priti Hegde. On-treatment changes in CRP as a surrogate for overall survival for atezolizumab benefit in 2nd line NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5707.

Phase II Trial of Atezolizumab As First-Line or Subsequent Therapy for Patients With Programmed Death-Ligand 1-Selected Advanced Non-Small-Cell Lung Cancer (BIRCH)

Purpose BIRCH was designed to examine the efficacy of atezolizumab, a humanized anti-programmed death-ligand 1 (PD-L1) monoclonal antibody, in advanced non-small-cell lung cancer (NSCLC) across lines of therapy. Patients were selected on the basis of PD-L1 expression on tumor cells (TC) or tumor-infiltrating immune cells (IC). Patients and Methods Eligible patients had advanced-stage NSCLC, no CNS metastases, and zero to two or more lines of prior chemotherapy. Patients whose tumors expressed PD-L1 using the SP142 immunohistochemistry assay on ≥ 5% of TC or IC (TC2/3 or IC2/3 [TC or IC ≥ 5% PD-L1-expressing cells, respectively]) were enrolled. Atezolizumab 1,200 mg was administered intravenously every 3 weeks. Efficacy-evaluable patients (N = 659) comprised three cohorts: first line (cohort 1; n = 139); second line (cohort 2; n = 268); and third line or higher (cohort 3; n = 252). The primary end point was independent review facility-assessed objective response rate (ORR; Response Evaluation Criteria in Solid Tumors [RECIST] version 1.1). Secondary end points included median duration of response, progression-free survival, and overall survival (OS). Results BIRCH met its primary objective of demonstrating a significant ORR versus historical controls. With a minimum of 12 months of follow-up, the independent review facility-assessed ORR was 18% to 22% for the three cohorts, and 26% to 31% for the TC3 or IC3 subgroup; most responses are ongoing. Responses occurred regardless of EGFR or KRAS mutation status. The median OS from an updated survival analysis (minimum of 20 month follow up) for cohort 1 was 23.5 months (26.9 months for TC3 or IC3 patients); the median OS in cohorts 2 and 3 was 15.5 and 13.2 months, respectively. The safety profile was similar across cohorts and consistent with previous atezolizumab monotherapy trials. Conclusion BIRCH demonstrated responses with atezolizumab monotherapy in patients with PD-L1-selected advanced NSCLC, with good tolerability. PD-L1 status may serve as a predictive biomarker for identifying patients most likely to benefit from atezolizumab.

Results From the Phase III Randomized Trial of Onartuzumab Plus Erlotinib Versus Erlotinib in Previously Treated Stage IIIB or IV Non-Small-Cell Lung Cancer: METLung

Purpose The phase III OAM4971g study (METLung) examined the efficacy and safety of onartuzumab plus erlotinib in patients with locally advanced or metastatic non-small-cell lung cancer selected by MET immunohistochemistry whose disease had progressed after treatment with a platinum-based chemotherapy regimen. Patients and Methods Patients were randomly assigned at a one-to-one ratio to receive onartuzumab (15 mg/kg intravenously on day 1 of each 21-day cycle) plus daily oral erlotinib 150 mg or intravenous placebo plus daily oral erlotinib 150 mg. The primary end point was overall survival (OS) in the intent-to-treat population. Secondary end points included median progression-free survival, overall response rate, biomarker analysis, and safety. Results A total of 499 patients were enrolled (onartuzumab, n = 250; placebo, n = 249). Median OS was 6.8 versus 9.1 months for onartuzumab versus placebo (stratified hazard ratio [HR], 1.27; 95% CI, 0.98 to 1.65; P = .067), with a greater number of deaths in the onartuzumab arm (130 [52%] v 114 [46%]). Median progression-free survival was 2.7 versus 2.6 months (stratified HR, 0.99; 95% CI, 0.81 to 1.20; P = .92), and overall response rate was 8.4% and 9.6% for onartuzumab versus placebo, respectively. Exploratory analyses using MET fluorescence in situ hybridization status and gene expression showed no benefit for onartuzumab; patients with EGFR mutations showed a trend toward shorter OS with onartuzumab treatment (HR, 4.68; 95% CI, 0.97 to 22.63). Grade 3 to 5 adverse events were reported by 56.0% and 51.2% of patients, with serious AEs in 33.9% and 30.7%, for experimental versus control arms, respectively. Conclusion Onartuzumab plus erlotinib did not improve clinical outcomes, with shorter OS in the onartuzumab arm, compared with erlotinib in patients with MET-positive non-small-cell lung cancer.

Randomized, phase II, placebo-controlled trial of onartuzumab and/or bevacizumab in combination with weekly paclitaxel in patients with metastatic triple-negative breast cancer

BACKGROUND

Increased hepatocyte growth factor/MET signaling is associated with an aggressive phenotype and poor prognosis in triple-negative breast cancer (TNBC). We evaluated the benefit of adding onartuzumab, a monoclonal anti-MET antibody, to paclitaxel with/without bevacizumab in patients with TNBC.

PATIENTS AND METHODS

Women with metastatic TNBC were randomized to receive onartuzumab plus placebo plus weekly paclitaxel (OP; n = 60) or onartuzumab plus bevacizumab plus paclitaxel (OBP; n = 63) or placebo plus bevacizumab plus paclitaxel (BP; n = 62). The primary end point was progression-free survival (PFS); additional end points included overall survival (OS), objective response rate (ORR), and safety. This trial was hypothesis generating and did not have power to detect minimum clinically meaningful differences between treatment arms.

RESULTS

There was no improvement in PFS with the addition of onartuzumab to BP [hazard ratio (HR), 1.08; 95% confidence interval (CI) 0.69-1.70]; the risk of a PFS event was higher with OP than with BP (HR, 1.74; 95% CI 1.13-2.68). Most patients had MET-negative tumors (88%); PAM50 subtype analysis showed basal-like tumors in 68% of samples. ORR was higher in the bevacizumab arms (OBP: 42.2%; 95% CI 28.6-57.1; BP: 54.7%; 95% CI 41.0-68.4) compared with OP (27.5%; 95% CI 15.9-40.6). Median OS was shorter with OBP (HR, 1.36; 95% CI 0.75-2.46) and OP (HR, 1.92; 95% CI 1.03-3.59), than with BP. Peripheral edema was more frequent in the onartuzumab arms (OBP, 51.8%; OP, 58.6%) versus BP (17.7%).

CONCLUSION

This study did not show a clinical benefit of the addition of onartuzumab to paclitaxel with/without bevacizumab in patients with predominantly MET-negative TNBC.

CLINICALTRIALSGOV

NCT01186991.

Onartuzumab with or without bevacizumab in combination with weekly paclitaxel does not prolong QTc or adversely affect other ECG parameters in patients with locally recurrent or metastatic triple-negative breast cancer

PURPOSE

The potential effect of onartuzumab, when administered with or without bevacizumab in combination with weekly paclitaxel, on the corrected QT interval (QTc) and other electrocardiogram (ECG) parameters, was investigated in a randomized, phase 2 study OAM4861g of first- or second-line therapy in patients with locally recurrent or metastatic triple-negative breast cancer.

METHODS

Triplicate 12-lead ECGs were recorded at screening, pre- and post-dose on day 1 of cycles 1, 2, and 4, and at the study drug discontinuation visit (SDDV). Onartuzumab serum samples were collected pre- and post-dose on day 1 of cycles 1-4 and at the SDDV. Fridericia's correction was applied to QT recordings (QTcF), and change from baseline (ΔQTcF) was calculated. Post-baseline measurements were reported as baseline-adjusted control arm (placebo plus bevacizumab plus paclitaxel)-corrected values (ΔΔQTcF). Categorical ECG findings were noted. Linear mixed effects modeling evaluated a potential concentration-ΔQTcF relationship.

RESULTS

Out of 185 enrolled patients, 165 patients had ECG-evaluable data for analyses. Similar ΔQTcF and ΔΔQTcF values were observed across all treatment arms, with mean increase <10 and <7 ms, respectively, across all time points. Similar changes in heart rate, PR interval, and QRS duration were noted across all treatment arms. Incidences of abnormal ECG findings of clinical interest were comparable in the onartuzumab-containing arms and the control arm. No concentration-ΔQTcF relationship was evident at onartuzumab serum concentrations up to 1,200 μg/ml.

CONCLUSIONS

These data suggest that onartuzumab, at the dose and exposures studied in this clinical trial, does not meaningfully affect the QTcF interval.

Laminin-411 is a vascular ligand for MCAM and facilitates TH17 cell entry into the CNS

TH17 cells enter tissues to facilitate pathogenic autoimmune responses, including multiple sclerosis (MS). However, the adhesion molecules involved in the unique migratory capacity of TH17 cells, into both inflamed and uninflamed tissues remain unclear. Herein, we characterize MCAM (CD146) as an adhesion molecule that defines human TH17 cells in the circulation; following in vitro restimulation of human memory T cells, nearly all of the capacity to secrete IL-17 is contained within the population of cells expressing MCAM. Furthermore, we identify the MCAM ligand as laminin 411, an isoform of laminin expressed within the vascular endothelial basement membranes under inflammatory as well as homeotstatic conditions. Purified MCAM-Fc binds to laminin 411 with an affinity of 27 nM, and recognizes vascular basement membranes in mouse and human tissue. MCAM-Fc binding was undetectable in tissue from mice with targeted deletion of laminin 411, indicating that laminin 411 is a major tissue ligand for MCAM. An anti-MCAM monoclonal antibody, selected for inhibition of laminin binding, as well as soluble MCAM-Fc, inhibited T cell adhesion to laminin 411 in vitro. When administered in vivo, the antibody reduced TH17 cell infiltration into the CNS and ameliorated disease in an animal model of MS. Our data suggest that MCAM and laminin 411 interact to facilitate TH17 cell entry into tissues and promote inflammation.

Reversal of polarized T helper 1 and T helper 2 cell populations in murine leishmaniasis

T helper 1 (Th1) and Th2 cells are the major subsets of fully differentiated CD4+ T cells in the mouse. The spectrum of cytokines characteristic of each subset determines the distinctive regulatory and effector functions mediated by each subset. We have used the murine model of Leishmania major infection to study the question of whether highly polarized populations of normal T cells are as stable in their cytokine phenotype as Th clones or whether the phenotype can be altered with regulatory cytokines. Interleukin 4 (IL-4) appears to be a key cytokine for Th2 responses as it is necessary for both the initial differentiation of Th responses to L. major and the stability of ongoing responses. Furthermore, IL-4 is capable of converting highly polarized Th1 responses to Th2 responses either in vitro or when adoptively transferred to severe combined immunodeficiency mice.

Allele and antigen-specific treatment of rheumatoid arthritis: a double blind, placebo controlled phase 1 trial

OBJECTIVE

Human cartilage glycoprotein 39 (HC gp-39) appears to be a relevant autoantigen in patients with rheumatoid arthritis (RA). Administration of major histocompatibility complex (MHC) Class II complexed antigens without requisite costimulatory signals can induce immunologic tolerance. We evaluated the safety, pharmacokinetics, and preliminary efficacy of AG4263 in patients with RA. AG4263 is a soluble complex of native HLA-DR4 (beta*0401) complexed to Org 36601, a 13-mer peptide derived from HC gp-39 (also referred to as CDP263).

METHODS

Thirty-one HLA-DRB1*0401 positive patients with persistent RA disease activity despite concurrent methotrexate were randomized to 7 infusions of AG4263 (n = 24) or placebo (n = 7) over 6 weeks. The initial dose of 0.5 micro g/kg was escalated in subsequent cohorts to a maximum of 150 micro g/kg. Safety analyses included recording of adverse events and measurement of CD4/CD8 counts, reactivity to recall antigens, and development of antibodies to HLA-DR4. Efficacy was assessed using the Paulus 20 criteria.

RESULTS

Treatment was well tolerated, with injection site reaction the most common adverse event. There was no loss of reactivity to recall antigens, change in cell counts, or antibodies to HLA-DR. The mean half-life of AG4263 was 12.5 h. Some evidence of clinical response was seen; responses were more common among patients receiving the highest doses of AG4263 and among those with baseline T cell reactivity to CDP263.

CONCLUSION

AG4263 was safe, well tolerated, and without evidence of generalized immune suppression. Along with the observed trend toward clinical efficacy, the results suggest that this therapeutic approach warrants further investigation in patients with RA.

The role of autoantigens in autoimmune disease

Many autoantigens have been identified in human patients and in rodent models. In numerous experimental settings, these autoantigens or related autoreactive lymphocytes can transfer autoimmunity. Although autoreactivity spreads to new epitopes during the course of disease, single-epitope-specific therapies show considerable efficacy in multi-epitope-induced models of autoimmunity. These observations may indicate that epitope-specific therapies operate at the level of regulating mechanisms of immune tolerance rather than exerting a direct effect on autoreactive T lymphocytes.

Chemokines in autoimmune diseases

Autoimmune diseases like multiple sclerosis (MS) and insulin-dependent diabetes (IDD) are believed to be mediated by pathogenic CD4+ autoreactive T cells which mediate selective destruction of specific host cells. Interrupting the trafficking of such T cells from host circulation to the sites of pathology, such as the central nervous system in the case of MS and the pancreas in the case of IDD, potentially offers a novel opportunity for therapeutic intervention in these diseases. The following summarizes our evolving thoughts on the role of the chemokine network in MS and IDD, and focuses on the chemokine receptor CXCR3 as a potential target for impeding T-cell-mediated destruction in these disease settings.

A phase I trial of solubilized DR2:MBP84-102 (AG284) in multiple sclerosis

OBJECTIVE

To assess the safety, tolerability, and biologic and clinical activity of a solubilized complex comprised of human leukocyte antigen-DR2 with myelin basic protein84-102 (AG284)in patients with secondary progressive MS.

BACKGROUND

Soluble species-specific major histocompatibility complex myelin basic protein91-103 complexes ameliorate disease in a dose-dependent manner when administered to SJL/J mice with chronic relapsing experimental allergic encephalomyelitis. Preincubation with AG284 reduces the proliferative response of a DR2-restricted, myelin basic protein84-102-reactive T cell clone, derived from a MS patient, to myelin basic protein84-102 in the presence of autologous antigen-presenting cells.

METHODS

Thirty-three patients with secondary progressive MS were randomly assigned to receive three alternate day IV doses of AG284 or placebo in a double-masked dose escalation study. The primary outcome was safety and tolerability. Secondary outcomes included a comparison of pre- and post-treatment gadolinium-enhanced brain MRI activity, Kurtzke Expanded Disability Status Scale, and Nine Hole Peg Test scores.

RESULTS

The frequency of adverse events was similar in the AG284 and placebo recipients. No significant treatment effect was detected by Expanded Disability Status Scale, Nine Hole Peg Test, or number of new gadolinium-enhancing MRI lesions.

CONCLUSIONS

AG284 as administered during this study was safe and well tolerated. Further studies are warranted to determine the biologic activity and clinical efficacy of this potential treatment for MS.

The cytokine stew and innate resistance to L. monocytogenes

The Listeria monocytogenes (L. monocytogenes) infection model has been a useful system to evaluate the cellular interactions leading to host immunity. The initiation of the innate immune response in naive animals and subsequent progression to acquired immunity represent an integrated system with numerous layers of complexity. Coincident with experimental infection is the induction of cytokines. Cytokines, which are soluble mediators of cell growth, maintenance and function, from a network of pleiotropic stimuli that serve as one of the main driving forces for the progressive development of cellular responses. A variety of in vivo approaches, such as injection of the recombinant cytokines themselves or antibodies to neutralize their activity, have been used to define these stimuli. Perhaps one of the most useful tools is that of germline-manipulated animals. One of the many cytokines implicated in resistance to L. monocytogenes infection is interleukin (IL)-6, a molecule associated with diverse infectious and pathophysiological disease states. This review concentrates on various cytokines (IL-1, TNF alpha, IFN-gamma, IL-12, IL-10 and the colony-stimulating factors (CSF)) thought to play a role during the innate host response to L. monocytogenes infection, with a special emphasis on studies using IL-6-deficient mice. Additionally, we show unpublished data obtained when the concepts learned from L. monocytogenes infection in IL-6-deficient mice were applied to other infection models.

Effect of the colony-stimulating factor-1 null mutation, osteopetrotic (csfm(op)), on the distribution of macrophages in the male mouse reproductive tract

Macrophages are found throughout the male reproductive tract and its accessory glands. Mice homozygous for a null mutation (csfm(op)) in the gene for the mononuclear phagocytic growth factor colony-stimulating factor-1 (CSF-1) have a significantly lower density of macrophages, defined by the mononuclear phagocytic antigen F4/80, in the testis, cauda and caput epididymis, prostate, seminal vesicles, and vas deferens. These data indicate that CSF-1 is the major growth factor regulating the occurrence of macrophages in male reproductive tissues. The residual macrophages were correctly located in the tissue except in the caput epididymis, where they failed to take up positions adjacent to the tubular epithelium. Restoration of circulating CSF-1 concentrations in csfm(op)/csfm(op) males totally restored F4/80+ cell density in the testis and caput and cauda epididymis and partially restored their density in the vas deferens and seminal vesicles but failed to affect density in the prostate. This failure to correct all populations with circulating CSF-1 suggests the requirement for local synthesis of CSF-1 at appropriate developmental stages and/or its expression in a cell surface-associated form. The absence of macrophages in the testis and epididymis of csfm(op)/csfm(op) mice correlates with dysfunction in these tissues, suggesting that macrophages play important nonimmunological roles in these tissues.

The mechanism of in vitro T helper cell type 1 to T helper cell type 2 switching in highly polarized Leishmania major-specific T cell populations

We have previously demonstrated that highly polarized CD4+ Th1 cells isolated from Leishmania major-infected mice could be switched to a Th2-like phenotype when cultured for 1 wk in the presence of APC, L. major Ag, and IL-4, suggesting that the reversion of a differentiated Th response could occur at the population level. To investigate the cellular basis for this population switch, CD4+ lymph node cells from Th1-polarized L. major-infected mice were separated into two subsets based on the level of expression of L-selectin (Mel-14), and each subset was stimulated with APC and IL-2 for 1 wk in the presence or the absence of IL-4. Mel-14low T cells contained all of the initial Th1 activity and retained their Th1 phenotype when cultured with IL-4. In contrast, Mel-14high T cells did not produce cytokines upon challenge with L. major Ag, but gave rise to a Th2-like population after culture with IL-4. Thus, the newly induced Th2 population was derived from undifferentiated cells distinct from the Th1 cells present in the starting population. This undifferentiated Th precursors could be induced to develop into either Th1 or Th2 cells and were not recent thymic emigrants as they were present in mice thymectomized before infection. These experiments show that a chronically stimulated and highly polarized Th1 population consisted of both precursor T cells able to differentiate into Th2 cells and cells fully differentiated into Th1 cells that could not be induced to switch their pattern of cytokine production.

The mechanism of in vitro T helper cell type 1 to T helper cell type 2 switching in highly polarized Leishmania major-specific T cell populations

We have previously demonstrated that highly polarized CD4+ Th1 cells isolated from Leishmania major-infected mice could be switched to a Th2-like phenotype when cultured for 1 wk in the presence of APC, L. major Ag, and IL-4, suggesting that the reversion of a differentiated Th response could occur at the population level. To investigate the cellular basis for this population switch, CD4+ lymph node cells from Th1-polarized L. major-infected mice were separated into two subsets based on the level of expression of L-selectin (Mel-14), and each subset was stimulated with APC and IL-2 for 1 wk in the presence or the absence of IL-4. Mel-14low T cells contained all of the initial Th1 activity and retained their Th1 phenotype when cultured with IL-4. In contrast, Mel-14high T cells did not produce cytokines upon challenge with L. major Ag, but gave rise to a Th2-like population after culture with IL-4. Thus, the newly induced Th2 population was derived from undifferentiated cells distinct from the Th1 cells present in the starting population. This undifferentiated Th precursors could be induced to develop into either Th1 or Th2 cells and were not recent thymic emigrants as they were present in mice thymectomized before infection. These experiments show that a chronically stimulated and highly polarized Th1 population consisted of both precursor T cells able to differentiate into Th2 cells and cells fully differentiated into Th1 cells that could not be induced to switch their pattern of cytokine production.