Immunotherapy combinations for the treatment of patients with solid tumors

Immune checkpoint inhibitors directed against CTLA-4, PD-1 and PD-L1 have transformed the treatment of patients with cancer. Immunotherapy regimens have evolved from a single agent approach to the combination of immune checkpoint inhibitors like anti CTLA-4 and PD-1, immune checkpoint blockade combined with chemotherapy, anti-angiogenic agents and kinase inhibitors. These synergistic combinations were developed to heighten the potency and duration of immune responses against cancer cells. Hence, immunotherapy combinations have shaped the landscape of therapeutic options against a wide range of cancer types, and are current standard treatment regimens worldwide. In this review, we describe the clinical evidence supporting the use of immunotherapy combination regimens for the treatment of patients with solid tumors.

LKB1/STK11 mutations in non-small cell lung cancer patients: Descriptive analysis and prognostic value

BACKGROUND

LKB1/STK11 (STK11) is among the most inactivated tumor-suppressor genes in non-small cell lung cancer (NSCLC). While evidence concerning the biologic role of STK11 is accumulating, its prognostic significance in advanced NSCLC has not been envisaged yet.

MATERIALS AND METHODS

This retrospective analysis included consecutive NSCLC patients with available STK11 information who underwent a platinum-based chemotherapy. STK11 mutational status was correlated to clinico-pathological and mutational features. Kaplan-Meier and Cox models were used for survival curves and multivariate analyses, respectively.

RESULTS

Among the 302 patients included, 267 (89%) were diagnosed with stage IIIB/IV NSCLC and 25 (8%) harbored a STK11 mutation (STK11mut). No statistical differences were observed between STK11 status and clinico-pathological variables. We detected a significant correlation between STK11 and KRAS status (p=0.008); among the 25 STK11mut patients, 13 (52%) harbored a concomitant KRAS mutation. Overall survival (OS) was shorter for STK11mut (median OS=10.4months) compared to wild-type patients (STK11wt; median OS=17.3months) in univariate analysis (p=0.085). STK11 status did not impact upon OS in multivariate analysis (p=0.45) and non-significant results were observed for progression-free survival. The co-occurrence of KRAS and STK11 mutations suggest a trend toward detrimental effect in OS (p=0.12).

CONCLUSIONS

In our cohort enriched for advanced NSCLC patients who received platinum-based chemotherapy, STK11 mutations were not specifically associated with clinico-pathological features and they did not impact upon survival. We confirm the positive correlation between STK11 and KRAS mutations. The co-occurrence of KRAS and STK11 mutations could label a more aggressive molecular subtype of NSCLC.

Prognostic value of HLA-A2 status in advanced non-small cell lung cancer patients

INTRODUCTION

The class I human leucocyte antigen (HLA) molecules play a critical role as an escape mechanism of antitumoral immunity. HLA-A2 status has been evaluated as a prognostic factor in lung cancer, mostly in localized disease and with inconsistent findings. We evaluated the role of HLA-A2 status as a prognostic factor in a large and homogeneus cohort of advanced NSCLC patients.

METHODS

Advanced NSCLC patients eligible for platinum-based chemotherapy were consecutively included in a single center between October 2009 and July 2015 in the prospective MSN study (NCT02105168). HLA-A2 status was analysed by flow cytometry. Clinical, pathological and molecular data were collected. A Cox model was used for prognostic analyses.

RESULTS

Of 545 stage IIIB/IV NSCLC patients included, 344 (63%) were male, 466 (85%) were smokers, 447 (83%) had PS 0-1, 508 (93%) had stage IV, 407 (75%) had an adenocarcinoma and median age was 61 years (range, 21-84). Incidence of patients with EGFRmut, ALK-positive and KRASmut was 14% (49/361), 9% (29/333) and 31% (107/350), respectively. The overall rate of HLA-A2 positivity was 48%. No association was observed between HLA-A2 status and any patient or tumor characteristics analyzed. With a median follow-up of 27.1 months, median OS was 12.8 months [95%CI 11.0-14.6] in HLA-A2+ vs. 12.5 months [95%CI 10.4-15.3] in HLA-A2- patients (HR 1.05 [95%CI 0.86-1.29], p=0.61). Median progression-free survival was similar in the two cohorts.

CONCLUSION

HLA-A2 status was not identified as prognostic for benefit in a large advanced NSCLC population treated with platinum-based chemotherapy.

Osimertinib benefit in EGFR-mutant NSCLC patients with T790M-mutation detected by circulating tumour DNA

Background

Approximately 50% of epidermal growth factor receptor (EGFR) mutant non-small cell lung cancer (NSCLC) patients treated with EGFR tyrosine kinase inhibitors (TKIs) will acquire resistance by the T790M mutation. Osimertinib is the standard of care in this situation. The present study assesses the efficacy of osimertinib when T790M status is determined in circulating cell-free tumour DNA (ctDNA) from blood samples in progressing advanced EGFR-mutant NSCLC patients.

Material and methods

ctDNA T790M mutational status was assessed by Inivata InVision™ (eTAm-Seq™) assay in 48 EGFR-mutant advanced NSCLC patients with acquired resistance to EGFR TKIs without a tissue biopsy between April 2015 and April 2016. Progressing T790M-positive NSCLC patients received osimertinib (80 mg daily). The objectives were to assess the response rate to osimertinib according to Response Evaluation Criteria in Solid Tumours (RECIST) 1.1, the progression-free survival (PFS) on osimertinib, and the percentage of T790M positive in ctDNA.

Results

The ctDNA T790M mutation was detected in 50% of NSCLC patients. Among assessable patients, osimertinib gave a partial response rate of 62.5% and a stable disease rate of 37.5%. All responses were confirmed responses. After median follow up of 8 months, median PFS by RECIST criteria was not achieved (95% CI: 4-NA), with 6- and 12-months PFS of 66.7% and 52%, respectively.

Conclusion(s)

ctDNA from liquid biopsy can be used as a surrogate marker for T790M in tumour tissue.

Abstract 2250: STK11 mutations in non-small cell lung cancer (NSCLC): descriptive analysis and prognostic significance

Background: STK11 (also called LKB1) is among the 3 most mutated genes in lung adenocarcinoma, but its prognostic and predictive significance in advanced NSCLC patients is still not clear. Recent preclinical and translational evidence suggest its role in conditioning KRAS mutant lung adenocarcinomas aggressiveness and response to targeted treatment.

Materials and methods: This retrospective analysis, in a single center, included consecutive NSCLC patients who had undergone a platinum-containing regimen, for which standard or next generation (NGS) sequencing analyses of STK11 gene (exons 1-9) had been successfully performed. STK11 gene was considered mutated if effect on protein was predicted as deleterious. Clinical features along with EGFR (exons 18-21), KRAS (exons 2-4) and TP53 (exons 1-11) mutational status were correlated to STK11 status. Kaplan-Meier methods, log-rank test, and Cox proportional hazards models were used for survival analysis, adjusting for stage (advanced yes/no) and histology for progression-free survival (PFS), and smoking status, stage, EGFR/KRAS status and number of lines of chemotherapy for overall survival (OS).

Results: Among the 302 patients included between November 2007 and January 2015, 63% were male, 16% non-smoker and median age was 60 year; 75% had an adenocarcinoma, 88% a stage IIIB or IV and 80% no previous treatment for advanced disease; 25 (8%) patients had a STK11 mutation, 30 (10%) an EGFR mutation and 81 (27%) a KRAS mutation. Deletions/insertions, missense and false-sense mutations mainly involved exon 4-6 of STK11. No statistical differences were observed between STK11 status and sex, smoking status, age, stage at diagnosis or histology (adenocarcinoma versus others). Among the 25 patients with STK11 mutation, 13 patients (52%) had a KRAS mutation, compared with 67 (24%) among those without STK11 mutation (p = 0.008). No correlation between STK11 and EGFR or TP53 mutational status was observed. Median follow-up time was 34.8 months (95% confidence interval [CI95]: 30.7-42.3). In univariate analysis, OS was shorter for STK11 mutated patients compared to wild type ones (p = 0.085; HR: 1.53; CI95: 0.94-2.49) with a median OS of 10.4 (CI95: 6.1-15.7) and 17.3 (CI95: 14.0-21.1) months for mutated and wild-type STK11 patients respectively. In multivariate analysis, the HR was 1.21 (CI95: 0.74-1.99; p = 0.45). Similar non-significant results were observed for PFS.

Conclusion: We confirm the reported data of a positive correlation between STK11 and KRAS mutations. No correlation between STK11 status and PFS or OS in patients receiving platinum-based treatment was observed when taking into account other prognostic covariates.

Citation Format: Francesco Facchinetti, Maria Virginia Bluthgen, Gabrielle Tergemina Clain, Laura Faivre, Jean-Pierre Pignon, David Planchard, Jean-Charles Soria, Benjamin Besse, Ludovic Lacroix. STK11 mutations in non-small cell lung cancer (NSCLC): descriptive analysis and prognostic significance. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2250.