Search

Hodgkin lymphoma (HL) was one of the first few cancers to be cured first with radiotherapy alone and then with a combination of chemotherapy and radiotherapy. Around 80% of the patients with HL will be cured by first-line therapy. However, the ionising radiation not only produces cytotoxicity but also induces alterations in the microenvironment, and patients often struggle with the long-term consequences of these treatments, such as cardiovascular disorders, lung diseases and secondary malignancies. Hence, it is essential to improve treatments while avoiding delayed side-effects. Immunotherapy is a promising new treatment option for Hodgkin lymphoma, and anti- programmed death-1 (PD1) agents have produced striking results in patients with relapsed or refractory disease. The microenvironment of Hodgkin lymphoma appears to be unique in the field of human disease: the malignant Reed-Sternberg cells only constitute 1% of the cells in the lymphoma, but they are surrounded by an extensive immune infiltrate. Reed-Sternberg cells exhibit 9p24.1/PD-L1/PD-L2 copy number alterations and genetic rearrangements associated with programmed cell death ligand 1/ ligand 2 (PD-L1/2) overexpression, together with major histocompatibility complex-I (MHC-I) and major histocompatibility complex-II (MHC-II) downregulation (which may facilitate the tumour's immune evasion). Although HL may be a situation in which defective immune surveillance is restored by anti-PD1 therapy, it challenges our current explanation of how anti-PD1 agents work because MHC-I expression is required for CD8-T-cell-mediated tumour antigen recognition. Here, we review recent attempts to understand the defects in immune recognition in HL and to design an optimal evidence-based treatment for combination with anti-PD1.

INTRODUCTION: Life expectancy evaluation is crucial when selecting patients who may benefit from phase I studies. The Royal Marsden Hospital (RMH) prognostic score, based on three objective variables (number of metastatic sites, lactate dehydrogenase (LDH) and serum albumin) was validated in patients treated with cytotoxics and targeted therapies. We aimed to determine if those factors were applicable to immune-checkpoint therapies (ICTs) in phase I trials and to evaluate new variables that may preclude a better prognosis in patients receiving ICT. PATIENTS AND METHODS: We conducted a retrospective analysis of survival risk factors in a discovery cohort of 155 patients enrolled into ICT phase I trials at our institution. We computed univariate analysis and multivariate analysis (MVA) of demographics, clinical and biological data to assess their prognostic value for overall survival (OS). MVA results were used to build a prognostic score for OS. A validation cohort of 113 patients enrolled in phase I ICT trials was used to prospectively validate this score. RESULTS: A total of 155 patients (M/F: 83/72; median age 59) receiving an experimental ICT between March 2012 and January 2016 were included in the discovery cohort. An MVA assessing the RMH score variables showed that low albumin (hazard ratio [HR] 1.73, 95% confidence interval [CI] 1.05-2.86) and LDH > upper limit normal (ULN) (HR 1.88, 95% CI 1.12-3.15) were independent negative prognostic factors for OS. Interestingly, neutrophil-to-lymphocyte ratio (NLR) > 6 (HR 1.75, 95% CI 1.04-2.95) was associated with a decrease in OS. The number of metastases was not associated with a poorer outcome for this ICT cohort (HR 0.83, 95% CI 0.51-1.35). A risk score based on the results of the MVA (NLR > 6 = 1; LDH > ULN = 1; albumin < 35 g/l = 1) showed that patients presenting a high score (>1) had a significantly shorter OS (20.4 weeks; 95% CI 5.7-35.2) compared to those with a low score (0 or 1) (68.9 weeks; 95% CI 50-83.7) (HR 2.9, 95% CI 1.87-4.64). In the validation cohort of 113 patients, again the patients presenting a high score showed an inferior OS (HR 6.3, 95% CI 2.7-14.8). CONCLUSION: In ICT phase I trials, traditional prognostic variables included in the RMH score may be suboptimal to determine patient's prognosis. In this context, the NLR is a significant prognostic variable. The Gustave Roussy Immune Score, based on albumin, LDH and NLR, allows a better selection of patients for ICT phase I trials.

Immune checkpoint blockade with antagonistic monoclonal antibodies (mAbs) targeting B7 immunoglobulin superfamily molecules (CTLA-4, PD-1, and PD-L1) generate long lasting anti-tumour immune responses translating into clinical benefit across many cancer types. However, many patients are primarily resistant to immune checkpoint blockade -based monotherapy and many others will eventually relapse. Therefore, new immunostimulatory targets are needed to overcome primary and secondary resistance to immunotherapy. Besides the B7 co-inhibitory receptors, the tumour necrosis factor receptor superfamily contains many other immune checkpoints, which could become the next generation immunomodulators. Among them stands OX40 (CD134), a co-stimulatory molecule that can be expressed by activated immune cells. Several anti-OX40 agonistic monoclonal antibodies are currently tested in early phase cancer clinical trials. Accumulating preclinical evidence supports their clinical development. However, conflicting results and controversies between in vitro and in vivo data point to the need for comprehensive ancillary studies to be performed in upcoming clinical trials to better understand the mechanism of action of anti-OX40 mAbs-based therapy.