Obinutuzumab Pretreatment as a Novel Approach to Mitigate Formation of Anti-Drug Antibodies Against Cergutuzumab Amunaleukin in Patients with Solid Tumors

PURPOSE

The immunocytokine cergutuzumab amunaleukin (CEA-IL2v) showed manageable safety and favorable pharmacodynamics in phase I/Ib trials in patients with advanced/metastatic carcinoembryonic antigen-positive (CEA+) solid tumors, but this was accompanied by a high incidence of anti-drug antibodies (ADA). We examined B-cell depletion with obinutuzumab as a potential mitigation strategy.

EXPERIMENTAL DESIGN

Preclinical data comparing B-cell depletion with rituximab versus obinutuzumab are summarized. Substudies of phase I/Ib trials investigated the effect of obinutuzumab pretreatment on ADA development, safety, pharmacodynamics, and antitumor activity of CEA-IL2v ± atezolizumab in patients with advanced/metastatic or unresectable CEA+ solid tumors who had progressed on standard of care.

RESULTS

Preclinical data showed superior B-cell depletion with obinutuzumab versus rituximab. In clinical studies, patients received CEA-IL2v monotherapy with (n = 16) or without (n = 6) obinutuzumab pretreatment (monotherapy study), or CEA-IL2v + atezolizumab + obinutuzumab pretreatment (n = 5; combination study). In the monotherapy study, after four cycles (every 2 weeks treatment), 0/15 evaluable patients administered obinutuzumab pretreatment had ADAs versus 4/6 patients without obinutuzumab. Obinutuzumab pretreatment with CEA-IL2v monotherapy showed no new safety signals and pharmacodynamic data suggested minimal impact on T cells and natural killer cells. Conversely, increased liver toxicity was observed in the combination study (CEA-IL2v + atezolizumab + obinutuzumab pretreatment).

CONCLUSIONS

These preliminary findings suggest that obinutuzumab pretreatment before CEA-IL2v administration in patients with CEA+ solid tumors may be a feasible and potent ADA mitigation strategy, with an acceptable safety profile, supporting broader investigation of obinutuzumab pretreatment for ADA mitigation in other settings.

A Phase I Trial of the Dual MET Kinase/OCT-2 Inhibitor OMO-1 in Metastatic Solid Malignancies Including MET Exon 14 Mutated Lung Cancer

INTRODUCTION

Targeted therapy in non-small cell lung cancer (NSCLC) patients with mesenchymal epithelial transition (MET) exon 14 skipping mutations (METex14) and MET amplifications has improved patients' outcomes. The development of more potent MET kinase inhibitors could further benefit these patients. The aim of this trial is to determine the safety and recommended phase 2 dose (RP2D) of OMO-1 (an oral dual MET kinase/OCT-2 inhibitor) and to assess preliminary clinical efficacy in METex14-positive NSCLC and other MET-positive solid tumors.

MATERIALS AND METHODS

This was a first-in-patient, open-label, multicenter study of OMO-1 in patients with locally advanced or metastatic solid malignancies. A standard 3 + 3 dose escalation design was utilized starting at a dose level of 100 mg BID continuously. Preliminary efficacy was investigated in patients with METex14-positive NSCLC, and MET amplified NSCLC and other solid tumors (MET basket).

RESULTS

In the dose-escalation part, 24 patients were included in 5 dose levels ranging from 100 mg twice daily (BID) to 400 mg BID. Most common adverse events (≥ 20%) were nausea, fatigue, vomiting, increased blood creatinine, and headache. The RP2D was determined at 250 mg BID. In the expansion cohorts, 15 patients were included (10 in METex14-positive NSCLC cohort and 5 in MET basket cohort) and received either 200 or 250 mg BID. Eight out of the 10 patients with METex14 positive NSCLC had stable disease as the best response.

CONCLUSION

OMO-1 was tolerated at the dose of 250 mg BID and shows initial signs of MET inhibition and anti-tumor activity in METex14 mutated NSCLC patients.

The search for therapeutic targets in lung cancer: Preclinical and human studies of carcinoembryonic antigen-related cell adhesion molecule 5 expression and its associated molecular landscape

OBJECTIVES

CEACAM5 is a cell-surface glycoprotein expressed on epithelial cells of some solid tumors. Tusamitamab ravtansine (SAR408701), a humanized antibody-drug conjugate targeting CEACAM5, is in clinical development for nonsquamous non-small cell lung cancer (NSQ-NSCLC) with CEACAM5 high expression (HE), defined as membranous CEACAM5 immunohistochemistry staining at ≥ 2+ intensity in ≥ 50% of tumor cells.

MATERIALS AND METHODS

We investigated correlations between CEACAM5 expression by immunohistochemistry, CEACAM5 protein expression by ELISA, and CEACAM5 RNA expression by RNA-seq in NSQ-NSCLC patient-derived xenograft (PDX) models, and tumor responses to tusamitamab ravtansine in these models. We assessed prevalence of CEACAM5 HE, clinicopathologic characteristics and molecular markers in patients with NSQ-NSCLC in clinical cohorts.

RESULTS

In a lung PDX set of 10 NSQ-NSCLC specimens, correlations between CEACAM5 by IHC, ELISA and RNA-seq ranged from 0.72 to 0.88. In a larger lung PDX set, higher H-scores were present in NSQ- (n = 93) vs SQ-NSCLC (n = 128) models, and in 12 of these NSQ-NSCLC models, more tumor responses to tusamitamab ravtansine occurred in CEACAM5 HE (5/8; 62.5%) versus moderate or negative expression (1/4; 25%), including 3 with KRAS mutations among the 6 responders. In clinical NSQ-NSCLC samples, CEACAM5 HE prevalence was (52/214; 24.3%) in primary tumors and (6/17; 35.3%) in metastases. In NSQ-NSCLC primary tumors, CEACAM5 HE prevalence was significantly higher in KRAS-altered versus wild-type (35.0% vs 19.5%; P = 0.028) and in programmed cell death ligand 1 (PD-L1) negative (tumor cells 0%)/low (1-49%) versus high (≥50%) (33.3%, 26.1%, 5.0%; P = 0.031), but not significantly different in EGFR-mutated versus wild-type (20.0% vs 25.7%, P = 0.626).

CONCLUSIONS

In NSQ-NSCLC tumors, CEACAM5 HE prevalence was 24.3% overall and was higher with KRAS altered and with PD-L1 negative/low tumors but similar regardless of EGFR mutation status. These findings support targeting CEACAM5 and the clinical development of tusamitamab ravtansine for patients with NSQ-NSCLC with CEACAM5 HE.

Phase Ib Study of Telisotuzumab Vedotin in Combination With Erlotinib in Patients With c-Met Protein-Expressing Non-Small-Cell Lung Cancer

PURPOSE

Overexpression of c-Met protein and epidermal growth factor receptor (EGFR) mutations can co-occur in non-small-cell lung cancer (NSCLC), providing strong rationale for dual targeting. Telisotuzumab vedotin (Teliso-V), a first-in-class antibody-drug conjugate targeting c-Met, has shown a tolerable safety profile and antitumor activity as monotherapy. Herein, we report the results of a phase Ib study (ClinicalTrials.gov identifier: NCT02099058) evaluating Teliso-V plus erlotinib, an EGFR tyrosine kinase inhibitor (TKI), in patients with c-Met-positive (+) NSCLC.

PATIENTS AND METHODS

This study evaluated Teliso-V (2.7 mg/kg once every 21 days) plus erlotinib (150 mg once daily) in adult patients (age ≥ 18 years) with c-Met+ NSCLC. Later enrollment required presence of an EGFR-activating mutation (EGFR-M+) and progression on a prior EGFR TKI. End points included safety, pharmacokinetics, objective response rate (ORR), and progression-free survival (PFS). The efficacy-evaluable population consisted of c-Met+ patients (confirmed histology [H]-score ≥ 150) who had at least one postbaseline scan; c-Met+ patients with H-scores ≥ 225 were classified as c-Met high.

RESULTS

As of January 2020, 42 patients were enrolled (N = 36 efficacy-evaluable). Neuropathies were the most common any-grade adverse events reported, with 24 of 42 patients (57%) experiencing at least one event. The pharmacokinetic profile of Teliso-V plus erlotinib was similar to Teliso-V monotherapy. Median PFS for all efficacy-evaluable patients was 5.9 months (95% CI, 2.8 to not reached). ORR for EGFR-M+ patients (n = 28) was 32.1%. Of EGFR-M+ patients, those who were c-Met high (n = 15) had an ORR of 52.6%. Median PFS was 6.8 months for non-T790M+ and for those whose T790M status was unknown, versus 3.7 months for T790M+.

CONCLUSION

Teliso-V plus erlotinib showed encouraging antitumor activity and acceptable toxicity in EGFR TKI-pretreated patients with EGFR-M+, c-Met+ NSCLC.

First-in-human study of an OX40 (ivuxolimab) and 4-1BB (utomilumab) agonistic antibody combination in patients with advanced solid tumors

BACKGROUND

Ivuxolimab (PF-04518600) and utomilumab (PF-05082566) are humanized agonistic IgG2 monoclonal antibodies against OX40 and 4-1BB, respectively. This first-in-human, multicenter, open-label, phase I, dose-escalation/dose-expansion study explored safety, tolerability, pharmacokinetics, pharmacodynamics, and antitumor activity of ivuxolimab+utomilumab in patients with advanced solid tumors.

METHODS

Dose-escalation: patients with advanced bladder, gastric, or cervical cancer, melanoma, head and neck squamous cell carcinoma, or non-small cell lung cancer (NSCLC) who were unresponsive to available therapies, had no standard therapy available or declined standard therapy were enrolled into five dose cohorts: ivuxolimab (0.1-3 mg/kg every 2 weeks (Q2W)) intravenously plus utomilumab (20 or 100 mg every 4 weeks (Q4W)) intravenously. Dose-expansion: patients with melanoma (n=10) and NSCLC (n=20) who progressed on prior anti-programmed death receptor 1/programmed death ligand-1 and/or anti-cytotoxic T-lymphocyte-associated antigen 4 (melanoma) received ivuxolimab 30 mg Q2W intravenously plus utomilumab 20 mg Q4W intravenously. Adverse events (AEs) were graded per National Cancer Institute Common Terminology Criteria for Adverse Events V.4.03 and efficacy was assessed using Response Evaluation Criteria in Solid Tumors (RECIST) V.1.1 and immune-related RECIST (irRECIST). Paired tumor biopsies and whole blood were collected to assess pharmacodynamic effects and immunophenotyping. Whole blood samples were collected longitudinally for immunophenotyping.

RESULTS

Dose-escalation: 57 patients were enrolled; 2 (3.5%) patients with melanoma (0.3 mg/kg+20 mg and 0.3 mg/kg+100 mg) achieved partial response (PR), 18 (31.6%) patients achieved stable disease (SD); the disease control rate (DCR) was 35.1% across all dose levels. Dose-expansion: 30 patients were enrolled; 1 patient with NSCLC achieved PR lasting >77 weeks. Seven of 10 patients with melanoma (70%) and 7 of 20 patients with NSCLC (35%) achieved SD: median (range) duration of SD was 18.9 (13.9-49.0) weeks for the melanoma cohort versus 24.1 (14.3-77.9+) weeks for the NSCLC cohort; DCR (NSCLC) was 40%. Grade 3-4 treatment-emergent AEs were reported in 28 (49.1%) patients versus 11 (36.7%) patients in dose-escalation and dose-expansion, respectively. There were no grade 5 AEs deemed attributable to treatment. Ivuxolimab area under the concentration-time curve increased in a dose-dependent manner at 0.3-3 mg/kg doses.

CONCLUSIONS

Ivuxolimab+utomilumab was found to be well tolerated and demonstrated preliminary antitumor activity in selected groups of patients.

TRIAL REGISTRATION NUMBER

NCT02315066.

A Phase 1b Study of Telisotuzumab Vedotin in Combination With Nivolumab in Patients With NSCLC

Introduction

Telisotuzumab vedotin (Teliso-V) is an anti-c-Met-directed antibody-drug conjugate that has exhibited antitumor activity as monotherapy in NSCLC. Its potential activity combined with programmed cell death protein-1 inhibitors has not been previously evaluated.

Methods

In a phase 1b study (NCT02099058), adult patients (≥18 y) with advanced NSCLC received combination therapy with Teliso-V (1.6, 1.9, or 2.2 mg/kg, every 2 wk) plus nivolumab (3 mg/kg, 240 mg, or per locally approved label). The primary objective was to assess safety and tolerability; secondary objectives included the evaluation of antitumor activity.

Results

As of January 2020, a total of 37 patients received treatment with Teliso-V (safety population) in combination with nivolumab; 27 patients (efficacy population) were c-Met immunohistochemistry-positive. Programmed death-ligand 1 (PD-L1) status was evaluated in the efficacy population (PD-L1-positive [PD-L1+]: n = 15; PD-L1-negative [PD-L1-]: n = 9; PD-L1-unknown: n = 3). The median age was 67 years and 74% (20 of 27) of patients were naive to immune checkpoint inhibitors. The most common any-grade treatment-related adverse events were fatigue (27%) and peripheral sensory neuropathy (19%). The pharmacokinetic profile of Teliso-V plus nivolumab was similar to Teliso-V monotherapy. The objective response rate was 7.4%, with two patients (PD-L1+, c-Met immunohistochemistry H-score 190, n = 1; PD-L1-, c-Met H-score 290, n = 1) having a confirmed partial response. Overall median progression-free survival was 7.2 months (PD-L1+: 7.2 mo; PD-L1-: 4.5 mo; PD-L1-unknown: not reached).

Conclusions

Combination therapy with Teliso-V plus nivolumab was well tolerated in patients with c-Met+ NSCLC with limited antitumor activity.

Phase I Study of 2- or 3-Week Dosing of Telisotuzumab Vedotin, an Antibody-Drug Conjugate Targeting c-Met, Monotherapy in Patients with Advanced Non-Small Cell Lung Carcinoma

PURPOSE

Telisotuzumab vedotin (Teliso-V) is an anti-c-Met-directed antibody-drug conjugate. Here, we present safety and efficacy data from a phase I/Ib study of Teliso-V monotherapy evaluated in once every 2 weeks/once every 3 weeks schedules in patients with non-small cell lung cancer (NSCLC).

PATIENTS AND METHODS

During dose escalation, patients received Teliso-V monotherapy intravenously once every 3 weeks (0.15-3.3 mg/kg) or once every 2 weeks (1.6-2.2 mg/kg). The dose-expansion phase enrolled patients with NSCLC and c-Met H-score ≥150 (c-Met+) or MET amplification/exon 14 skipping mutations. Safety, pharmacokinetics, and efficacy were assessed. Herein, the analysis of patients receiving ≥1.6 mg/kg once every 2 weeks or ≥2.4 mg/kg once every 3 weeks Teliso-V is reported.

RESULTS

Fifty-two patients with NSCLC were enrolled and received ≥1.6 mg/kg Teliso-V once every 2 weeks (n = 28) or ≥2.4 mg/kg Teliso-V once every 3 weeks (n = 24). The most common adverse events were fatigue (54%), peripheral neuropathy (42%), and nausea (38%). No dose-limiting toxicities were observed for Teliso-V once every 2 weeks and once every 3 weeks up to 2.2 and 2.7 mg/kg, respectively. The recommended phase II dose was established at 1.9 mg/kg once every 2 weeks and 2.7 mg/kg once every 3 weeks on the basis of overall safety and pharmacokinetics. Forty of 52 patients were c-Met+ (33 nonsquamous, 6 squamous, 1 mixed histology) and were included in the efficacy-evaluable population. Of those, 9 (23%) had objective responses with median duration of response of 8.7 months; median progression-free survival was 5.2 months.

CONCLUSIONS

Teliso-V monotherapy was tolerated and showed antitumor activity in c-Met+ NSCLC. On the basis of overall safety, pharmacokinetics, and efficacy outcomes, 1.9 mg/kg Teliso-V once every 2 weeks and 2.7 mg/kg once every 3 weeks schedules were selected for further clinical development.

284 Integrated molecular characterization of primary resistance mechanisms to immune checkpoint blockade in advanced non-small cell lung carcinoma (a-NSCLC)

Background

Reinvigoration of anti-tumor immunity via immune checkpoint blockade (ICB) has transformed outcomes in a-NSCLC. However, a majority of patients are innately resistant to ICB, and a better understanding of the resistance mechanisms may guide the development of new treatment strategies and therapies for patients.

Methods

Biopsies performed immediately before treatment with single agent ICB in patients with a-NSCLC (MATCH-R trial [NCT02517892]) were analyzed. The stromal microenvironment and immune context were characterized via an integrated analysis of whole transcriptome (RNA-seq), whole exome sequencing (WES), and immunohistochemistry (IHC) of CD3, CD8, FOXP3 and PDL1. Specifically, the immune context and the relative abundance of 10 immune and stromal cell types were assessed with integrated IHC and Cell Populations-counter (MCP-counter) [1] analysis of the RNA-seq. Somatic mutations and Tumor Mutation Burden (TMB) were evaluated. The transcriptional state of the tumor and its microenvironment were assessed by GSVA analysis [2] of the MSigDB collection [3]. Patient‘s outcome was associated to molecular data. Primary resistance to ICB was defined as PD (progressive disease) in the first radiological examination, or a median PFS inferior to 3 months.

Results

Fifty-two patients with NSCLC were enrolled (43 adeno, 6 squamous, and 3 other carcinoma): Median age was 61 (34–93), 18 were female, 46 were smokers, 22 were responders, and 30 were non-responders. Median tumor cellularity was 60% (30%–90%).Patients may be divided into two groups (HIGH and LOW) at baseline based on their degree of immune infiltration as assessed by RNAseq or IHC. A hallmark of the HIGH infiltration group is an increase in Interferon Gamma (IFN-γ) pathway signature [4]. In contrast, patients in the LOW infiltration group (relative to the HIGH infiltration group) exhibit a decrease in IFN-γ pathway signaling and concomitantly an increase in hypoxia and gluconeogenic pathway signatures. Response rates to ICB were not associated to immune infiltration groups at baseline, but an analysis within each infiltration group revealed that high TMB is only associated to response in the HIGH infiltration group. Furthermore, only in the LOW infiltration group was increased the transforming growth factor (TGF-β) pathway signature associated to ICB response.

Conclusions

This study suggests that the tumor and its microenvironment influence baseline immune infiltration. Tumors with LOW baseline infiltration show altered metabolism such as gluconeogenic activation and hypoxia activation. In contrast, factors such as TMB are not associated with baseline infiltration

Inducible T-cell co-stimulatory (ICOS) receptor agonist, feladilimab (fela), alone and in combination (combo) with pembrolizumab (P): Results from INDUCE-1 urothelial carcinoma (UC) expansion cohorts (ECs)

4519

Background: INDUCE-1 is a first-in-human trial evaluating fela, an IgG4 ICOS agonist non-T-cell depleting mAb, as monotherapy (mono) and in combo with P. ECs include tumor types, such as UC, with high ICOS expression and immunotherapy-favorable features. Fela induced IFNγ, increased PD-1/L1 expression, and enhanced antitumor activity in combo with PD-1 blockade nonclinically. We report preliminary efficacy, safety, and biomarker data of fela ± P in INDUCE-1 UC ECs. Methods: Eligible patients (pts) had recurrent/metastatic (R/M) UC of the upper or lower urinary tract, ≤6 prior systemic therapy lines in the advanced setting, measurable disease, and no active autoimmune disease. Pts received 0.3 or 1 mg/kg fela (mono EC; anti-PD-1/L1–experienced [exp] pts) or 0.3 mg/kg fela + 200 mg P (combo EC; anti-PD-1/L1–naïve pts) every 3 wks, up to 35 cycles until disease progression or unacceptable toxicity. Disease was assessed every 9 wks through wk 54, then every 12 wks. Archival and/or fresh biopsy tumor tissue was collected for biomarker analyses and safety assessed. Results: By Nov 6 2020, 13 anti-PD-1/L1–exp and 32 anti-PD-1/L1–naïve pts were evaluable in the mono and combo ECs, respectively. In the mono EC, median age was 69 yrs (range: 47–82), 92% of pts were male, and 85% received ≥2 prior therapy lines in the metastatic setting. In the combo EC, median age was 70 yrs (range: 42–84), 75% of pts were male, and 72% received ≥1 prior therapy line in the metastatic setting. In the mono EC, median duration of follow-up (mDoF) was 10.6 mo (range: 1.1–22.8); overall response rate (ORR) was 8% (1 partial response [PR]; 95% CI: 0.2, 36.0) with a duration of response (DoR) of 6.1 mo; disease control rate (DCR [response or stable disease for ≥9 wks]) was 23% (95% CI: 5.0, 53.8), and median overall survival (mOS) was 14.5 mo (95% CI: 2.8, NR), with 74% of pts alive at 6 mo. In the combo EC, mDoF was 9.6 mo (range: 0.9–28.3); ORR was 22% (7 PRs; 95% CI: 9.3, 40.0) with a median DoR of 8.3 months (range: 3.5–23.3+); DCR was 63% (95% CI: 43.7, 78.9), and mOS was 10.7 mo (95% CI: 5.2, 18.1), with 64% of pts alive at 6 mo. Grade ≥3 treatment-related AEs were reported for 0% and 9% of pts in the mono (N = 16) and combo (N = 44) safety populations, respectively. PD-L1 expression and ICOS-specific biomarkers are being evaluated, with promising trends observed in enrichment of clinical activity in preliminary analyses. Conclusions: Fela is the first ICOS agonist with reported single-agent activity in anti-PD-1/L1–exp relapsed/refractory UC. Fela + P in combo shows promising clinical activity and manageable safety in PD-1/L1–naïve R/M UC. Further study is warranted. Updated data to be presented. Funding: Study 204691 (NCT02723955) funded by GlaxoSmithKline in collaboration with Merck Sharp & Dohme Corp, a subsidiary of Merck & Co, Inc, Kenilworth, NJ, USA. Clinical trial information: NCT02723955.

Chemotherapy beyond immune checkpoint inhibitors in patients with metastatic colorectal cancer

BACKGROUND

Immune checkpoint inhibitors (ICIs) alone or in combination with chemotherapy (CT) are the current standard of therapy in several cancer types. Patients (pts) with lung cancer display higher response rates to CT when given after ICIs. Although ICIs have failed to demonstrate antitumour activity in microsatellite stable (MSS) metastatic colorectal cancer (mCRC), little is known about CT effect after ICIs. We aimed to assess whether sequential ICIs followed by CT may be an alternative therapeutic approach in a population of pts with mCRC.

MATERIAL AND METHODS

We retrospectively assessed CT after ICI (CAICI) failure in pts with mCRC. The ICI regimen consisted of anti-PD(L)1 alone or in combination. The primary end-point was objective response rate. Progression-free survival (PFS) and overall survival (OS) were secondary end-points.

RESULTS

Between 2014 and 2018, 29 pts with mCRC received CAICI (MSS tumours, 27 pts [86%]). The median number of previous lines was 4 (range, 2-7). Regimens included TAS-102 (n = 14), FOLFIRI (irinotecan, leucovorin, and fluorouracil; n = 6) or FOLFOX (oxaliplatin, leucovorin, and fluorouracil; n = 4), regorafenib (n = 3) and carboplatin (1 pt with BRCA mutation). Partial response and stable disease were observed in 4 (19%) and 9 (43%) pts, respectively (disease control rate, 62%). The median PFS and OS were 3.8 months (95% confidence interval [CI] = 1.5-5.4) and 8.0 months (95% CI = 4.2-14.0), respectively.

CONCLUSION

ICIs administered before CT might enhance cytotoxic effects even in pts with immunorefractory MSS mCRC. The results of this small cohort need to be validated in independent prospective cohorts. The role of ICIs as modifiers of both tumour cells and microenvironment in mCRC deserves further research.

Updated analysis of the inducible T-cell co-stimulatory receptor (ICOS) agonist, GSK3359609 (GSK609), combination with pembrolizumab (PE) in patients (pts) with anti-PD-1/L1 treatment-naïve head and neck squamous cell carcinoma (HNSCC)

6517

Background: INDUCE-1 (NCT02723955) is a first-in-human study investigating GSK609, an IgG4 ICOS agonist non-T-cell depleting antibody, as monotherapy and combination therapy with anti-cancer agents that includes PE. A range of GSK609 dose levels (≥0.1–1 mg/kg) having biological and clinical activity were identified and evaluated in the expansion phase with GSK609 0.3 mg/kg selected as the dose for further investigation. Results from the HNSCC expansion cohorts (ECs) showed GSK609 has single agent activity in pts with relapsed/refractory disease, and early clinical activity in combination with PE in pts with anti-PD-1/L1 treatment-naïve disease (Rischin, et al. Annals of Oncol 2019;30[Supplement_5]:v454–5). Updated results from the GSK609/PE HNSCC EC are presented. Methods: Eligible pts for the HNSCC EC had anti-PD-1/L1 treatment-naïve disease, ≤5 prior lines of therapy, measurable disease, and no active autoimmune disease. Pts received GSK609 0.3 mg/kg + PE 200 mg every 3 weeks (wks) until disease progression or unacceptable toxicity, up to 2 years (yrs)/35 cycles. Disease assessments were performed every 9 wks through wk 54 then every 12 wks thereafter. Pts were followed for survival and subsequent anti-cancer therapy. Results: As of 11 October 2019, 34 pts were enrolled and evaluable for efficacy analyses. The median age of this population was 61.5 yrs (range: 37–77); 85% were male; 53% received ≥1 prior line of therapy in the metastatic setting. ORR was 26% (95% CI: 12.9, 44.4; n = 9 with 4 complete and 5 partial responses); disease control rate was 68% (95% CI: 49.5, 82.6; n = 23). Among pts with PD-L1 IHC status by 22C3 pharmDx assay (n = 24; 71%), the majority of pts with a response or stable disease (SD) had PD-L1 CPS status < 20 (11 of 15 pts including 1 SD pt with CPS < 1). Median PFS was 5.6 months (95% CI: 3.9, 6,2). Median OS was not reached at time of analysis (95% CI: 8.2, NR); 6-month OS rate was 84% (95% CI: 66, 93). Treatment-related adverse events were reported in 66% of pts; the majority of events were Grades 1 or 2 with < 10% of pts experiencing ≥ Grade 3 events. Conclusions: This updated analysis with a more mature dataset shows promising clinical activity that supports further randomized investigation of GSK609 in combination with PE with an OS endpoint in HNSCC. Clinical trial information: NCT02723955 .

Diverse Resistance Mechanisms to the Third-Generation ALK Inhibitor Lorlatinib in ALK-Rearranged Lung Cancer

PURPOSE

Lorlatinib is a third-generation anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitor with proven efficacy in patients with ALK-rearranged lung cancer previously treated with first- and second-generation ALK inhibitors. Beside compound mutations in the ALK kinase domain, other resistance mechanisms driving lorlatinib resistance remain unknown. We aimed to characterize the mechanisms of resistance to lorlatinib occurring in patients with ALK-rearranged lung cancer and design new therapeutic strategies in this setting.

EXPERIMENTAL DESIGN

Resistance mechanisms were investigated in 5 patients resistant to lorlatinib. Longitudinal tumor biopsies were studied using high-throughput next-generation sequencing. Patient-derived models were developed to characterize the acquired resistance mechanisms, and Ba/F3 cell mutants were generated to study the effect of novel ALK compound mutations. Drug combinatory strategies were evaluated in vitro and in vivo to overcome lorlatinib resistance.

RESULTS

Diverse biological mechanisms leading to lorlatinib resistance were identified. Epithelial-mesenchymal transition (EMT) mediated resistance in two patient-derived cell lines and was susceptible to dual SRC and ALK inhibition. We characterized three ALK kinase domain compound mutations occurring in patients, L1196M/D1203N, F1174L/G1202R, and C1156Y/G1269A, with differential susceptibility to ALK inhibition by lorlatinib. We identified a novel bypass mechanism of resistance caused by NF2 loss-of-function mutations, conferring sensitivity to treatment with mTOR inhibitors.

CONCLUSIONS

This study shows that mechanisms of resistance to lorlatinib are diverse and complex, requiring new therapeutic strategies to tailor treatment upon disease progression.

Abstract 2268: Agonistic T cell non depleting ICOS antibody strongly enhances anti-tumor activity with CTLA4 blocking monoclonal antibody without exacerbating colitis

Background: ICOS is a member of the CD28 superfamily mainly expressed on activated T cells. An up-regulation of ICOS+ T cells is observed in patients treated with ipilimumab. These findings prompt further studies examining the synergy between CTLA-4 blockade and ICOS stimulation in generating optimal anti-tumor T cell immunity.

Methods: Peripheral blood mononuclear cells (PBMC) were collected from French patients with metastatic melanoma and treated with ipilimumab at baseline (V1) and after 1-2 ipilimumab infusion and restimulated in vitro with anti-CD3 plus anti-human non-depleting agonist ICOS IgG4 isotype antibodies. T cell proliferation and cytokine secretion was determined after 24 and 48h incubation. For in vivo experiments, C57Bl/6 and BALB/c mice were inoculated subcutaneously with MC38 and CT26 tumor cell lines respectively. Mice received intraperitoneal injections of anti-CTLA4 or its isotype control along with anti-mouse ICOS or corresponding isotype at D7, D10 and D13 with tumor growth assessments three times a week.

Results: PBMC collected from patients that respond to anti-CTLA-4 mAb exhibited stronger activation of T cells at baseline compared to patients with poor benefit. Treatment with a non-depleting agonist ICOS IgG4 mAb was able to rescue T cell activation in PBMC from patients with poor benefit. Furthermore, ICOS IgG4 with concurrent TCR engagement favored IL-10 secretion in patients that do not develop colitis during ipilimumab treatment suggesting that these patients may be protected from colitis due to a stronger capacity to secrete IL-10 after ipilimumab blockade particularly when ICOS is stimulated. In both mouse tumor models, combination with agonist non-depleting ICOS mAb increased the anti-CTLA-4 tumor activity without any colitis development.

Conclusion: This study provides evidence in mice and in humans that non-depleting agonistic ICOS mAb may increase anti-CTLA-4 tumor activity particularly in patients that do not benefit from anti-CTLA-4 alone without exacerbation of colitis.

Citation Format: Clélia Coutzac, Jean Jouniaux, Aurore Vozy, Marc Ballas, Sara Brett, Sapna Yadavilli, Eric Angevin, Axel Hoos, Nathalie Chaput. Agonistic T cell non depleting ICOS antibody strongly enhances anti-tumor activity with CTLA4 blocking monoclonal antibody without exacerbating colitis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2268.

Abstract 311: Diverse biological mechanisms drive resistance to Lorlatinib in ALK-rearranged Lung Cancer

Background: ALK rearrangements occur in 3-6% of patients (pts) with lung adenocarcinoma. Lorlatinib, is a novel third generation ALK tyrosine kinase inhibitor (TKI) with proven efficacy for patients previously treated with second generation ALK TKI.

Methods: The MATCH-R study is a prospective single-institution trial aiming to identify mechanisms of resistance to targeted agents and immunotherapy in pts with advanced cancer (NCT02517892). Patients that achieve an initial partial or complete response or stability of disease for at least 6 months with selected agents are included upon disease progression. Tumor biopsies are performed and serial blood samples are collected. Extensive molecular profiling with panel next-generation sequencing (NGS), whole exome sequencing (WES) and RNA sequencing (RNAseq) is performed on tumor samples. Patient-derived xenografts (PDX) in NOD scid gamma (NSG) or nude mice and patient-derived cell lines are developed. We report mechanisms of resistance in a cohort of pts with ALK-rearranged lung cancer treated with lorlatinib.

Results: From June 29th 2015 to November 15th 2018, 113 pts treated with a TKI were included in the MATCH-R study, of which 14 (12%) received treatment with ALK TKI, 6 pts treated with lorlatinib and with adequate tumor biopsies for molecular analysis were included. Tumor types studied were lung adenocarcinoma (n=4), anaplastic thyroid carcinoma (ATC, n=1) and myofibroblastic inflammatory tumor (MIT, n=1). An NF2 frame-shift deletion was detected by NGS in the ATC sample and a TNIK Q674 missense mutation was detected in the MIT sample. In the four pts with lung cancer treated with lorlatinib, we identified novel ALK G1202R/F1174L compound mutations from the tumor biopsy in one case and characterized them with Ba/F3 models (ctDNA analysis will be presented). Induction of epithelial mesenchymal transition (EMT) with lorlatinib exposure was responsible for resistance in one patient-derived model and susceptible to combined ALK/SRC inhibition. This cell line also had ALK C1156Y/G1269A compound mutations, not contributing to lorlatinib resistance. In a third case, double deleterious events in NF2 were identified in temporo-spatial distinct tumor biopsies on progression to lorlatinib. We further validated the effect of these events in patient-derived cell lines developed from two different biopsies. Downstream mTOR pathway activation conferred resistance to lorlatinib, and was reversible with mTOR inhibitors. We performed NF2 knockout in H3122 cells using Crispr-Cas9 gene editing to validate these findings. The resistance mechanism to lorlatinib treatment is yet to be elucidated in one patient-derived model.

Conclusions: Mechanisms of resistance to lorlatinib can be diverse and complex, involving compound mutations, EMT and bypass activation. The present evidence could provide new insights for the development of tailored treatments for patients.

Citation Format: Gonzalo Recondo, Laura Mezquita, David Planchard, Anas Gazzah, Francesco Facchinetti, Ludovic Bigot, Ahsan Z. Rizvi, Jean-Paul Thiery, Jean-Yves Scoazec, Rosa L. Frias, Tony Sourisseau, Linda Mahjoubi, Justine Galissant, Aurelie Abou-Lovergne, Gilles Vassal, Rastislav Bahleda, Antoine Hollebecque, Claudio Nicotra, Maud Ngocamus, Stefan Michiels, Ludovic Lacroix, Catherine Richon, Nathalie Auger, Thierry De Baere, Frederic Deschamps, Eric Solary, Ken A. Olaussen, Eric Angevin, Alexander Eggermont, Fabrice André, Christophe Massard, Jean-Charles Soria, Benjamin Besse, Luc Friboulet. Diverse biological mechanisms drive resistance to Lorlatinib in ALK-rearranged Lung Cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 311.

Abstract 318: Mechanisms of acquired resistance to FGFR inhibitors in molecularly-selected solid tumors: A prospective cohort from the MATCH-R study

Background: Molecular alterations involving FGFR family genes (FGFR 1-4) are emerging driver events in a variety of solid tumors, mainly represented by urothelial carcinoma (UC) and intrahepatic cholangiocarcinoma (CC). Several tyrosine kinase inhibitors (TKI) are in clinical development to counteract FGFR-driven diseases, being especially active against activating gene mutations and rearrangements. Progression on these targeted agents eventually appears and the understanding of molecular mechanisms of resistance is crucial to develop novel strategies.

Methods: In the MATCH-R prospective study (NCT02517892), patients with unresectable or metastatic cancer are included upon acquired resistance to targeted therapies or immunotherapy, defined as progressive disease after complete/partial response or stable disease for six months. Serial blood samples are collected and tumor biopsy is performed upon progression. Targeted NGS, CGH, WES and RNAseq are performed on the tissue samples. PDX models and patient-derived cell lines are developed to fully investigate the underlying mechanisms of resistance. Only patients receiving TKI for FGFR-mutated or -rearranged tumors were included (i.e. FGFRamplifications were excluded) in the analysis.

Results: From June 2015 to November 2018, 113 patients treated with a TKI were included in the MATCH-R study, of which 17 (15%) had received an FGFR inhibitor. Tumor types and corresponding molecular aberrations were as follows: 8 CC (n=6 FGFR2-rearranged, n=1 FGFR2:C383R, n=1 FGFR3:S249C), 7 UC (n=5 FGFR3:S249C, n=1 FGFR3:R248C, n=1 FGFR3:Y373C), 1 breast (FGFR3-rearranged) and 1 ovarian (FGFR2-rearranged) cancers. Evaluable tumor biopsies were taken upon progression to treatment with erdafitinib (n=12), pemigatinib (INCB54828) (n=3) or TAS-120 (n=4). Two patients underwent multiple biopsies as progressing on sequential FGFR inhibitors. Resistance mechanisms consisted of polyclonal secondary mutations (n=5), bypass pathways activation (n=3) and the remaining nine cases are still under investigation. PDX models/patient-derived cell lines were obtained in eight cases and extensively characterized in three. Adaptive treatment with novel FGFR TKI or combinatorial strategies aiming to block the bypass pathways allowed to restore sensitivity in both cell lines (readouts: IC50 and Western Blots) and PDX (readout: median tumor growth). Novel mutations potentially implicated in resistance to FGFR TKI were characterized by infecting Ba/F3 cells with respective lentiviral vectors, as well as the inhibitory potential of the differential FGFR inhibitors.

Conclusions: Novel mechanisms of resistance to FGFR inhibitors in solid tumors were identified and consequent treatment strategies allowed to regain sensitivity in both patient-derived cell lines and PDX. Updated results will be presented at the Meeting.

Citation Format: Francesco Facchinetti, Rastislav Bahleda, Antoine Hollebecque, Yohann Loriot, Gonzalo Recondo, Ludovic Bigot, Ken A. Olaussen, Gilles Vassal, Stefan Michiels, Rosa L. Frias, Justine Galissant, Tony Sourisseau, Claudio Nicotra, Maud Ngo-Camus, Linda Mahjoubi, Ludovic Lacroix, Etienne Rouleau, Catherine Richon, Aurélie Abou-Lovergne, Olivier Deas, Nathalie Auger, Thierry De Baere, Frederic Deschamps, Eric Solary, Jean-Yves Scoazec, Eric Angevin, Alexander Eggermont, Fabrice André, Benjamin Besse, Jean-Paul Thiery, Jean-Charles Soria, Christophe Massard, Luc Friboulet. Mechanisms of acquired resistance to FGFR inhibitors in molecularly-selected solid tumors: A prospective cohort from the MATCH-R study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 318.

Pan-tumor prognostic value of multiple immune protein expressions

2618

Background: Using multiple immune-checkpoint proteins (ICP) screening in clinical routine could improve the evaluation of patients’ prognosis and ultimately tailor their treatment choice. We have evaluated this hypothesis in the context of early drug clinical trials. Methods: Patients included in MOSCATO-02 trial had refractory cancers and were candidate for phase 1 study. They were proposed to have a biopsy on an accessible tumor site for the analysis of four proteins by immunohistochemistry (IHC) and RNAseq: PD-L1, CD3, CD8 and FOXP3. Quantification of IHC staining was separated between intratumoral, intersitial and stromal by semi-quantitative method. Their relations to prognosis have been evaluated by survival Random Forest and compared to classical prognosis clinical variables, such as age and RMH score (calculated by the number of metastatic sites, lactate dehydrogenase (LDH) and serum albumin). Results: From April 2016 to September 2017, 228 patients included in MOSCATO-02 had a successful biopsy procedure with available IHC expression analysis. The main tumor subtypes were gastro-intestinal, urological, head and neck, breast and lung. RNAseq analyzes were performed for two thirds of the patients (N=170). Median overall survival was 8.1 months (CI95% 7.79 – 10, 65). We found that, in a cohort of phase I patients, RMH score was the most important variable used to estimate prognosis. Prognosis value of immune proteins were considerably inferior compared to clinical criteria. Among those proteins, the percentage of PD-L1 low score (1+) and average staining intensity of CD3 were the most valuables for prognosis evaluation. Variables with very few importance to prognosis estimation were CD8 and FOXP3 IHC scores, biopsy site and cancer types, subsequent treatments by immunotherapies or targeted therapies. Conclusions: In this cohort of patients with refractory cancers, the RMH score is confirmed as highly prognosis. Immune proteins could be used as a support to guide patient’s selection but does not constitute effective prognosis criteria.

Results of the phase 1b study of ABBV-399 (telisotuzumab vedotin; teliso-v) in combination with erlotinib in patients with c-Met+ non-small cell lung cancer by EGFR mutation status

3011

Background: Telisotuzumab vedotin (ABBV-399; teliso-v [T]) is a c-Met–targeted antibody and MMAE drug conjugate. Activity of T was shown in late-line c-Met+ non-small cell lung cancer (NSCLC) irrespective of EGFR mutation (M+) status. We present mature data from the T+ erlotinib (E) cohort of a phase 1b study (NCT02099058) by EGFR M+ status. Methods: T was administered at 2.4 mg/kg (dose-escalation phase) or 2.7 mg/kg IV Q3W, and E at 150 mg PO QD/prior tolerated dose in adult patients (pts) with advanced NSCLC. Efficacy-evaluable pts were c-Met+ (central lab IHC H-score ≥150 or local lab MET amplification/Ex 14 skipping) and had ≥1 postbaseline scan or discontinued study. EGFR M+ was defined as del19 or L858R by local lab. PK was assessed. Results: As of Dec 2018, 42 NSCLC pts received T+E; 37 were c-MET+ (36 evaluable; 35 H-score≥150, 1 MET amplified). Median age was 65 years, 25 pts (69%) had ECOG PS 1, 29 (81%) were EGFR M+ (97% had prior EGFR TKI, 55% 3rd-generation TKI, 69% TKI as last prior therapy, and 62% platinum doublet). All-grade (Gr; ≥20%) adverse events (AEs) were dermatitis acneiform (38%), diarrhea (36%), peripheral motor/sensory neuropathy (52%; 7% Gr 3), dyspnea, fatigue, hypoalbuminemia (31% each), decreased appetite, nausea (24% each), asthenia, vomiting (21% each). Gr ≥3 (≥10%) AE: pulmonary embolism (14%). PK of T+E was similar to single-agent T. The table presents efficacy data. Conclusions: These data suggest acceptable safety and promising activity of T+E and support further study in EGFR M+ c-Met+ NSCLC pts for whom frontline EGFR TKI failed. Clinical trial information: NCT02099058. [Table: see text]

Modular phase I/II clinical trial evaluating the selective MET-kinase inhibitor OMO-1 in patients with advanced malignancies: Safety and proof of mechanism

3062

Background: MET kinase is a therapeutic target in a range of cancer indications; it is a primary oncogenic driver and a mechanism of therapy resistance. OMO-1 is a highly potent, selective oral inhibitor of MET kinase and Organic Cation Transporter 2 (OCT2). Methods: This study assesses the safety, tolerability, pharmacokinetics (PK) and preliminary activity of OMO-1 in patients (pts) with advanced malignancies (NCT03138083). Module 1 data, evaluating ascending doses of OMO-1 monotherapy, are reported here. Results: As of January 16, 2019, 34 pts were enrolled at 5 twice-daily (BD) dose levels of OMO-1: 100, 200, 250, 350, and 400 mg, including 10 with MET gene amplified or mutated tumours. OMO-1 was generally well tolerated between 100 - 250 mg BD; pts were in the study for an average of 94 days (range: 15-291 days) and 20/34 pts discontinued due to disease progression. Most frequently-reported AEs were nausea (17/34), vomiting (14/34) and fatigue (14/34), mainly G1-2. Notably, no peripheral oedema, cardiovascular events or non-malignancy related LFT abnormalities were observed. A total of 36 SAEs were reported: 17 in 11 subjects were considered related to OMO-1, and included nausea (3/17), vomiting (4/17), chills, diarrhoea, influenza-like illness (2/17), increased blood bilirubin, blood creatinine (3/17) and neutrophil count, and sepsis. A dose of 250 mg BD was determined as the recommended Phase 2 dose (RP2D); doses ≥350mg BD were not in keeping with optimum long-term dosing: at 400 mg BD, 2/3 subjects experienced influenza-like illness (G2 and G3) and at 350 mg BD 2/5 subjects had G2 fatigue and nausea/vomiting. OMO-1 has a half-life of 2.5-3 hrs and plasma exposure is dose-proportional without accumulation. Elevated creatinine was observed across all dose levels, consistent with OCT2 inhibition. IHC analysis on paired tumour biopsies from a MET-mutated NSCLC pt dosed at 200 mg BD showed near-complete inhibition of phosphorylated MET, without affecting total MET. Conclusions: OMO-1 has a favourable safety profile at a RP2D of 250mg BD. Expansion cohorts for MET mutated/amplified tumour types are enrolling. Clinical trial information: NCT03138083.

Immunothérapie des glioblastomes

IMMUNOTHERAPY IN GLIOBLASTOMAS

Targeting the immune system as a therapeutic strategy in solid tumors has shown great efficacy in various tumor types. However the role and success of this approach in glioblastomas remain to be determined. Recent studies demonstrated that central nervous system is no longer considered as an immunoprivileged sanctuary with impressive immune response without blood brain barrier's disruption. Improving our understanding of immune privilege in the central nervous system could lead to better treatment strategies in gliobastomas. This review focuses on describing the immune system in the central nervous system and immuno-therapeutic strategies under development in glioblastomas.

First-in-Human Phase I, Dose-Escalation and -Expansion Study of Telisotuzumab Vedotin, an Antibody–Drug Conjugate Targeting c-Met, in Patients With Advanced Solid Tumors

Purpose

This first-in-human study evaluated telisotuzumab vedotin (Teliso-V), formerly called ABBV-399, an antibody–drug conjugate of the anti–c-Met monoclonal antibody ABT-700 and monomethyl auristatin E.

Materials and Methods

For dose escalation, three to six patients with advanced solid tumors were enrolled in eight cohorts (0.15 to 3.3 mg/kg). The dose-expansion phase enrolled patients with non–small-cell lung cancer (NSCLC) with c-Met–overexpressing tumors (c-Met positive; immunohistochemistry membrane H-score ≥ 150). Patients received Teliso-V monotherapy intravenously on day 1 once every 3 weeks. Safety, tolerability, pharmacokinetics, and maximum tolerated dose were determined.

Results

Forty-eight patients were enrolled (median age, 65 years; 35.4% NSCLC; median four prior therapies). One patient each in the 3.0-mg/kg (n = 9) and 3.3-mg/kg (n = 3) cohorts experienced dose-limiting toxicities. Although the maximum tolerated dose was not formally identified, the recommended phase II dose was defined as 2.7 mg/kg on the basis of overall safety and tolerability. The most frequent treatment-emergent adverse events (any grade) were fatigue (42%), nausea (27%), constipation (27%), decreased appetite (23%), vomiting (21%), dyspnea (21%), diarrhea (19%), peripheral edema (19%), and neuropathy (17%). The most frequent Teliso-V–related grade ≥ 3 adverse events were fatigue, anemia, neutropenia, and hypoalbuminemia (4% each). Teliso-V and total antibody pharmacokinetics were approximately dose proportional, with a mean harmonic half-life of 2 to 4 days each. Prospective screening identified 35 (60%) of 58 patients with c-Met–positive NSCLC. Of 16 patients with c-Met–positive NSCLC who were treated with Teliso-V 2.4 to 3.0 mg/kg, three (18.8%; 95% CI, 4.1% to 45.7%) achieved a partial response (median response duration, 4.8 months; median progression-free survival, 5.7 months; 95% CI, 1.2 months to 15.4 months). No other patients experienced a response.

Conclusion

Teliso-V monotherapy demonstrated favorable safety and tolerability profiles, with encouraging evidence of antitumor activity in patients with c-Met–positive NSCLC.

Long-Term Survival in Patients Responding to Anti-PD-1/PD-L1 Therapy and Disease Outcome upon Treatment Discontinuation

PURPOSE

Anti-PD-(L)1 can provide overall survival (OS) benefits over conventional treatments for patients with many different cancer types. However, the long-term outcome of cancer patients responding to these therapies remains unknown. This study is an exploratory study that aimed to describe the long-term survival of patients responding to anti-PD-(L)1 monotherapy across multiple cancer types.Patients and Methods: Data from patients treated with an anti-PD-(L)1 monotherapy in a phase I trial at Gustave Roussy were retrospectively analyzed over a period of 5 years. All cancer types (n = 19) were included. Clinical and biological factors associated with response, long-term survival, and secondary refractory disease were studied.

RESULTS

Among 262 eligible patients, the overall objective response rate was 29%. The median progression-free survival of responder patients (RP) at 3 months was 30 months, and the median OS of RP was not reached after a median follow-up of 34 months. In RPs, 3- and 5-year OS percentages were 84% and 64%, respectively. No death occurred in the 21 complete responders (CR) during the overall follow-up. However, many partial responders (PR) showed subsequent tumor relapses to treatment. Long responders (response ≥2 years) represented 11.8% of the overall population. These findings should be validated in further prospective studies.

CONCLUSIONS

There are currently no differences in therapeutic strategies between CRs and PRs to anti-PD-(L)1. We found a striking difference in OS between these two types of responses. Our results are in favor of evaluating patient stratification strategies and intensification of treatments when tumor lesions of a partial responder to immunotherapy stop improving.See related commentary by Cohen and Flaherty, p. 910.

Organisational factors influencing early clinical trials enrollment: Gustave Roussy experience

PURPOSE

Enrolment process influences the likelihood of patients' inclusion in early clinical trials (ECT) through social, medical and organisational factors.

PATIENTS AND METHODS

All patients referred from 2008 to 2016 to the Drug Development Department (DITEP) of Gustave Roussy (GR) were reviewed. Referring physician, organisational factors, medical and socioeconomic characteristics for patients were analysed. Multivariate analysis was performed with regard to those factors. A telephone survey was conducted on a sample of referring physicians located outside GR (N = 142).

RESULTS

Between 2008 and 2016, 8694 requests were received with 49% from external physicians. Here, 4517 were male patients with a median age of 58 [49-66] years (range 18-85). Tumour types were gastrointestinal (28%), lung (19%), breast (9%) and gynaecologic (8%). Mean enrolment rate was 37% (ranging from 24 to 45%). From 2008 to 2016, the enrolment rate decreases from 39% to 24%. In the meantime, DITEP trials portfolio evolves with the part of precision medicine trials increase from 12% to 40%. Factors that were significantly associated with a lower likelihood of being enrolled were referral from an external physician (OR 0.15 s.16-0.21]) compared to a physician from DITEP and year of the request (2.74 [1.8-2.9] 2008 versus 2016). The enrolment rate and the number of patients addressed have a high variability regarding referring physicians, which is little explained by characteristics as training, previous experience or attitude regarding ECT.

CONCLUSION

Beyond patients' individual characteristics, we show that organisational and professional factors have a major impact on likelihood of enrolment in ECT.

Efficacy of histology-agnostic and molecularly-driven HER2 inhibitors for refractory cancers

A targeted therapy is recommended in case of ERBB2 alteration for breast and gastric carcinomas, but miscellaneous other tumor types are ERBB2-altered at low prevalence. Broadening the administration of HER2 inhibitors across tumor types and genomic alterations could benefit to patients with refractory metastatic tumors.

Targeted next-generation-sequencing (tNGS) and comparative genomic hybridization array (CGH) have been performed on fresh tumor biopsies of patients included in the MOSCATO-01 and ongoing MOSCATO-02 trials to administrate HER2 inhibitors in case of ERBB2 pathogenic mutation of amplification.

Between December 2011 and January 2017 a molecular analysis was performed for 934 patients (759 CGH and 912 tNGS). A novel ERBB2 alteration has been found in 4.7% (n = 44/934), including 1.5% (n = 14/912) ERBB2 mutations, and 4% (n = 30/759) ERBB2 amplifications.

A matched HER2 inhibitor was administrated to 70% (31/44) of patients and consisted in trastuzumab plus chemotherapy for 90% of them (28/31). On the 31 evaluable patients, 1 complete response (CR), 10 partial response (PR) and 2 stable disease (SD) >24 weeks were observed accounting for a clinical benefit rate (CBR) of 42% (n = 13/31, 95% CI 25–61%). Besides breast and oesogastric carcinomas, 19 patients affected by 8 different tumor types had a CBR of 25% for ERBB2 mutations (n = 2/8, 95% CI 3%–65%, with 2 PR) and 64% for ERBB2 amplifications (n = 7/11, 95% CI 31%–89%; with 1 CR, 4 PR, 2 SD).

ERBB2 genomic alterations were diffuse across metastatic tumor types and signs of efficacy emerged for HER2 targeted treatments, especially in case of ERBB2 amplifications or a p.S310Y ERBB2 mutation.

Isolation and characterization of renal cancer stem cells from patient-derived xenografts

As rapidly developing patient-derived xenografts (PDX) could represent potential sources of cancer stem cells (CSC), we selected and characterized non-cultured PDX cell suspensions from four different renal carcinomas (RCC). Only the cell suspensions from the serial xenografts (PDX-1 and PDX-2) of an undifferentiated RCC (RCC-41) adapted to the selective CSC medium. The cell suspension derived from the original tumor specimen (RCC-41-P-0) did not adapt to the selective medium and strongly expressed CSC-like markers (CD133 and CD105) together with the non-CSC tumor marker E-cadherin. In comparison, PDX-1 and PDX-2 cells exhibited evolution in their phenotype since PDX-1 cells were CD133^high/CD105-/Ecad^low and PDX-2 cells were CD133^low/CD105-/Ecad-. Both PDX subsets expressed additional stem cell markers (CD146/CD29/OCT4/NANOG/Nestin) but still contained non-CSC tumor cells. Therefore, using different cell sorting strategies, we characterized 3 different putative CSC subsets (RCC-41-PDX-1/CD132+, RCC-41-PDX-2/CD133-/EpCAM^low and RCC-41-PDX-2/CD133⁺/EpCAM^bright). In addition, transcriptomic analysis showed that RCC-41-PDX-2/CD133⁻ over-expressed the pluripotency gene ERBB4, while RCC-41-PDX-2/CD133⁺ over-expressed several tumor suppressor genes. These three CSC subsets displayed ALDH activity, formed serial spheroids and developed serial tumors in SCID mice, although RCC-41-PDX-1/CD132⁺ and RCC-41-PDX-2/CD133⁺ displayed less efficiently the above CSC properties. RCC-41-PDX-1/CD132⁺ tumors showed vessels of human origin with CSC displaying peri-vascular distribution. By contrast, RCC-41-PDX-2 originated tumors exhibiting only vessels of mouse origin without CSC peri-vascular distribution.

Altogether, our results indicate that PDX murine microenvironment promotes a continuous redesign of CSC phenotype, unmasking CSC subsets potentially present in a single RCC or generating ex novo different CSC-like subsets.

A first-in-human phase I study of SAR125844, a selective MET tyrosine kinase inhibitor, in patients with advanced solid tumours with MET amplification

PURPOSE

Dysregulated MET signalling is implicated in oncogenesis. The safety and preliminary efficacy of a highly selective MET kinase inhibitor (SAR125844) was investigated in patients with advanced solid tumours and MET dysregulation.

METHODS

This was a phase I dose-escalation (3 + 3 design [50-740 mg/m²]) and dose-expansion study. In the dose escalation, patients had high total MET (t-MET) expression by immunohistochemistry (IHC) or MET amplification by fluorescence in situ hybridisation. In the dose expansion, patients had MET amplification (including a subset of patients with non-small cell lung cancer [NSCLC]) or phosphorylated-MET (p-MET) expression (IHC). Objectives were determination of maximum tolerated dose (MTD) of once-weekly intravenous SAR125844 based on dose-limiting toxicities; safety and pharmacokinetic profile; preliminary efficacy of SAR125844 MTD in the expansion cohort.

RESULTS

In total, 72 patients were enrolled: dose escalation, N = 33; dose expansion, N = 39; 570 mg/m² was established as the MTD. Most frequent treatment-emergent adverse events (AEs) were asthenia/fatigue (58.3%), nausea (31.9%), and abdominal pain, constipation, and dyspnea (27.8% for each); 58.3% of patients reported grade 3 AEs (19.4% were treatment related). Of the 29 evaluable patients with MET amplification treated at 570 mg/m², five achieved a partial response, including four of 22 with NSCLC; 17 patients had stable disease. No response was observed in patients with high p-MET solid tumours. There was no correlation between tumour response and t-MET status or MET gene copy number.

CONCLUSION

The MTD of once-weekly SAR125844 was 570 mg/m²; SAR125844 was well tolerated, with significant antitumour activity in patients with MET-amplified NSCLC.

CLINICAL TRIAL REGISTRATION NUMBER

NCT01391533.

Cost analysis of adverse events associated with non-small cell lung cancer management in France

Background

Adverse events (AEs) related to medical treatments in non-small cell lung cancer (NSCLC) are frequent and need an appropriate costing in health economic models. Nevertheless, data on costs associated with AEs in NSCLC are scarce, particularly since the development of immunotherapy with specific immune-related AEs.

Objective

To estimate the costs of grades 3 and 4 AEs related to NSCLC treatments including immunotherapy in France.

Methods

Grades 3 and 4 AEs related to treatment and reported in at least 1% of patients in Phase III clinical trials for erlotinib, ramucirumab plus docetaxel, docetaxel, pemetrexed plus carboplatin plus bevacizumab, platinum-based chemotherapies, nivolumab and pembrolizumab were identified. When no cost evaluation was reported in literature, estimates on standard treatments and medical resource use for each AE were obtained thanks to an expert panel. Total cost per AE was calculated from a French national health insurance perspective and updated in 2017 Euros. Hospital stay costs were estimated based on public and private weighted tariffs and data from the French Medical Information System (Programme de Médicalisation des Systèmes d’Information). Costs of tests, consultations and treatments were calculated based on national reimbursement tariffs.

Results

Overall, costs of grades 3 and 4 AEs related to treatment ranged from €46 per event to €7,742 per year. Fourteen out of 24 AEs identified had a mean estimated cost over €2,000. The highest mean costs were related to type 1 diabetes (€7,742 per year) followed by pneumonitis (€5,786 per event), anemia (€5,752 per event), dehydration (€5,207 per event) and anorexia (€4,349 per event). Costs were mostly driven by hospitalization costs.

Conclusion

Among the AEs identified, a majority appeared to have an important economic impact, with a management cost of at least €2,000 per event mainly driven by hospitalization costs. This study may be of interest for economic evaluations of new interventions in NSCLC.

Safety, tolerability and antitumour activity of LY2780301 (p70S6K/AKT inhibitor) in combination with gemcitabine in molecularly selected patients with advanced or metastatic cancer: a phase IB dose escalation study

BACKGROUND

LY2780301, a dual inhibitor of protein kinase B (AKT) and the downstream effector p70 ribosomal protein S6 kinase (p70S6K), may inhibit progression in tumours relying on phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signalling pathway activation. This phase IB trial investigated the maximum tolerated dose (MTD), dose-limiting toxicities (DLTs), safety, pharmacokinetics (PK) and antitumour activity of LY2780301 plus gemcitabine in patients with advanced/metastatic solid tumours.

METHODS

This was a non-randomised, open-label, dose escalation and dose expansion trial. Patients harbouring molecular alterations of the PI3K/AKT/mTOR pathway received once daily (QD) oral LY2780301 (400 or 500 mg) in combination with intravenous gemcitabine (750 or 1000 mg/m²) on days 1, 8 and 15 of a 28-d cycle. Dose escalation followed a 3 + 3 design. Assessments included adverse events (AEs), PK and preliminary antitumour activity.

RESULTS

Fifty patients (median age, 53 years; 74% female) predominantly with mutations/amplifications of PI3K (60%) and phosphatase and tensin homologue (PTEN) gene/protein inactivation (42%) were treated for up to 14 cycles. The MTD was LY2780301 500 mg QD with gemcitabine 750 mg/m². DLTs during cycle 1 were grade IV thrombocytopenia, grade III skin rash and grade III increase in alkaline phosphatase, gamma glutamyltransferase and alanine aminotransferase, occurring in one patient each. Most common AEs were anaemia (84%), fatigue (84%), transaminase increase (74%), thrombocytopenia (74%), nausea/vomiting (70%), neutropenia (68%) and lymphopenia (56%). Among the efficacy-evaluable population, two patients (5%) had a partial response; the disease control rate was 74% at cycle 2.

CONCLUSIONS

Addition of LY2780301 to gemcitabine showed manageable toxicity and encouraging antitumour activity in patients with molecular alterations of the PI3K/AKT/mTOR pathway.

CLINICAL TRIAL REGISTRATION NUMBER

NCT02018874.

Abstract 1011: RNAseq analysis obtained from on-purpose tumor biopsies of patients in the MATCH-R trial allows the identification of potential mechanisms of acquired resistance to PD(L)1 therapies

Background: MATCH-R is a prospective molecular characterization trial (NCT02517892) aiming at defining the molecular basis of acquired resistance to targeted agents and immune checkpoint blockers. RNA sequencing (RNAseq) has been used to identify mechanisms of secondary resistance to immunotherapy.

Patients and methods: Patients’ metastatic tumors were multi-site biopsied at relapse under immunotherapies after a period of clinical benefit, defined by a partial response or a stable disease of more than 6 months. Genome-wide RNAseq counts were intra-patient normalized and a score of each gene’s expression was computed in comparison to a cohort of 450 metastatic cancer patients with RNAseq available at the time of analysis.

Results: To date, 10 patients treated by immunotherapies have had a successful RNAseq in the MATCH-R trial. Five patients were treated with PD-1 inhibitors and 5 with PD-L1 inhibitors. Three patients had NSCLC, 2 MSI high endometrial carcinoma, 2 anal carcinoma, 2 urothelial carcinoma and 1 TNBC. Eight out off ten patients had an expression of IDO1 higher than the median expression of IDO1 in our 450 controls (p value = 0.005). A patient with endometrial carcinoma had one of the highest expressions of IDO1 in the cohort. Consistently, IDO1 activation has previously been reported as a mechanism of secondary resistance to immunotherapies. A 40 year old smoker NSCLC patient with a TP53 mutation has been treated during 11 months with anti-PD1. RNAseq analysis on the biopsy of a progressive lesion showed decreased expression of different actors of the JAK-STAT pathway (biopsy composed of 40% tumor cells and 60% microenvironment). Of the 78 genes signatures used (including 52 immunogenes signatures), the interferon gamma signature had the lowest expression (p value = 0.004), consistent with a previous report of JAK-STAT-induced resistance to immunotherapy. Two more patients had an altered immune profile that could be involved in resistance to immunotherapies, but was not yet reported in the litterature. Confirmation of the RNAseq analysis with immunohistochemistry is currently ongoing. The gene signatures of the 10 patients, composed of immunogenes, DNA repair genes and epigenes, were compared to the whole cohort in order to deduce corresponding false discovery rates. As such we could identify 2 gene clusters, one enriched in T cells, dendritic cells and macrophages, and the other enriched in epigenes and DNA repair genes. Analysis of more patients is currently ongoing in order to cluster the results with clinical characteristics.

Conclusion: Gene expression in the biopsy of patients that relapsed after initial benefit to immunotherapy is informative and helps to identify the mechanism of acquired resistance.

Citation Format: Loic Verlingue, Linda Mahjoubi, Sandrine Aspeslagh, Marion Pedrero, Giulia Buzzatti, David Brandao, Zsofia Balogh, Etienne Rouleau, Ludovic Lacroix, Rastislav Bahleda, Christophe Massard, Antoine Hollebecque, Anas Gazzah, Céline Lefebvre, Serge Koscielny, Jean Yves Scoazec, Eric Angevin, Fabrice André, Aurélien Marabelle, Jean Charles Soria. RNAseq analysis obtained from on-purpose tumor biopsies of patients in the MATCH-R trial allows the identification of potential mechanisms of acquired resistance to PD(L)1 therapies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1011. doi:10.1158/1538-7445.AM2017-1011

INDUCE-1: A phase I open-label study of GSK3359609, an ICOS agonist antibody, administered alone and in combination with pembrolizumab in patients with advanced solid tumors

TPS3113

Background: Inducible T cell Co-Stimulator (ICOS), a member of the CD28/B7/CTLA-4 receptor superfamily expressed on T cells after engagement with cognate antigen and activation, provides a co-stimulatory signal augmenting T cell proliferation, survival and cytokine production. GSK3359609 is a humanized IgG4 antibody selected for its potent agonist activity against human ICOS. The unique mechanistic profile of an ICOS agonist antibody, such as GSK3359609, offers an opportunity to investigate the antitumor potential of targeting a T cell co-stimulator alone and in combination with other cancer immunotherapies such as pembrolizumab. Methods: INDUCE-1 is a first- in-human study evaluating safety, pharmacokinetics, pharmacodynamics, immunogenicity, and preliminary antitumor activity of GSK3359609 administered as an intravenous (IV) infusion once every 3 weeks (Q3W) alone (Part 1) and in combination with 200 mg pembrolizumab (Q3W IV infusion) or other immunotherapy (Part 2) in approximately 304 adult patients. In dose escalation, eligible patients are required to have selected relapsed/refractory solid tumors. Primary objective is to determine safety, tolerability, and maximum tolerated or administered dose. Modified toxicity probability interval method will inform dose escalation decisions (minimum 3 patients per dose level [DL]). In expansion, cohorts may be defined by factors such as tumor histology, biomarker features, or prior treatment. More than one GSK3359609 DL may be evaluated in an expansion cohort by random assignment. Blood immunophenotyping is monitored in all patients; tumor biopsies (before and on-treatment) are optional in escalation and required in expansion to provide biomarker data that may inform on optimal dose selection as well as mechanistic understanding of GSK3359609. Efficacy measures are every 9 weeks and are according to immune-related RECIST. As of 7 Feb 2017, the first 3 monotherapy DL cohorts completed without dose limiting toxicities; DL 4 enrollment is ongoing. Study is funded by GlaxoSmithKline and is in collaboration with Merck & Co., Inc. Clinical trial information: NCT02723955.

Phase I study of ABBV-399, a c-Met antibody-drug conjugate (ADC), as monotherapy and in combination with erlotinib in patients (pts) with non-small cell lung cancer (NSCLC)

2509

Background: The c-Met receptor is overexpressed in ~50% of pts with NSCLC. ABBV-399 is a first-in-class ADC composed of ABT-700, an anti–c-Met antibody, conjugated to monomethyl auristatin E (a microtubule inhibitor). Preclinical data demonstrate that ABBV-399 can deliver a potent cytotoxin directly to c-Met+ tumor cells. Methods: ABBV-399 was administered at doses ranging from 2.4 to 3.0 mg/kg (dose expansion and combination cohorts at 2.7 mg/kg) once every 21 days to 29 pts with advanced c-Met+ (immunohistochemistry [IHC] H-score ≥150) NSCLC both as monotherapy (ABBV-399/monoT; 16 pts) and in combination with oral erlotinib 150 mg daily (ABBV-399/ERL; 13 pts) (NCT02099058). c-Met overexpression was assessed by IHC utilizing the SP44 antibody (Ventana; Tucson, AZ, USA). Results: As of January 9, 2017, 16 pts with c-Met+ NSCLC received ≥1 dose of ABBV-399/monoT. Monotherapy treatment-related adverse events (TRAEs) occurring in ≥10% of pts (all dose levels and all grades) were fatigue (43.8%), nausea (37.5%), neuropathy (25.0%), vomiting (18.8%), and anemia, constipation, and diarrhea (12.5% each). Three of 16 (19%) ABBV-399–treated c-Met+ NSCLC pts had a confirmed partial response (PR) with duration of response (DOR) 3, 4.5, and 10+ months. At week 12, 6 of 16 pts (37.5%) had disease control. TRAEs in ABBV-399/ERL occurring in ≥10% of pts (all grades) were neuropathy (30.8%), and acneiform rash, diarrhea, fatigue, nausea, and dry skin (15.4% each). Four of 13 (31%) evaluable ABBV-399/ERL–treated c-Met+ pts had a PR (3 confirmed, 1 unconfirmed) with DOR 1+, 2.7, 5.3+, and 11+ months. Three of the 4 pts with PR had EGFR-mutated tumor and recently progressed on TKI. At week 12, 8 of 13 pts (61.5%) had disease control. There were no treatment-related deaths as monotherapy or in combination with erlotinib. Responses were seen in both squamous and non-squamous histology. Conclusions: ABBV-399 is well tolerated at 2.7 mg/kg once every 21 days and has demonstrated antitumor activity in pts with c-Met+ NSCLC both as monotherapy and in combination with erlotinib. Updated efficacy/safety data and MET gene status will be presented. Clinical trial information: NCT02099058.