Targeted Natural Killer Cell–Based Adoptive Immunotherapy for the Treatment of Patients with NSCLC after Radiochemotherapy: A Randomized Phase II Clinical Trial

Abstract

Purpose: Non-small cell lung cancer (NSCLC) is a fatal disease with poor prognosis. A membrane-bound form of Hsp70 (mHsp70) which is selectively expressed on high-risk tumors serves as a target for mHsp70-targeting natural killer (NK) cells. Patients with advanced mHsp70-positive NSCLC may therefore benefit from a therapeutic intervention involving mHsp70-targeting NK cells. The randomized phase II clinical trial (EudraCT2008-002130-30) explores tolerability and efficacy of ex vivo-activated NK cells in patients with NSCLC after radiochemotherapy (RCT). Patients and Methods: Patients with unresectable, mHsp70positive NSCLC (stage IIIa/b) received 4 cycles of autologous NK cells activated ex vivo with TKD/IL2 [interventional arm (INT)] after RCT (60-70 Gy, platinum-based chemotherapy) or RCT alone [control arm (CTRL)]. The primary objective was progression-free survival (PFS), and secondary objectives were the assessment of quality of life (QoL, QLQ-LC13), toxicity, and immunobiological responses. Results: The NK-cell therapy after RCT was well tolerated, and no differences in QoL parameters between the two study arms were detected. Estimated 1-year probabilities for PFS were 67% [95% confidence interval (CI), 19%-90%] for the INT arm and 33% (95% CI, 5%-68%) for the CTRL arm (P ¼ 0.36, 1-sided logrank test). Clinical responses in the INT group were associated with an increase in the prevalence of activated NK cells in their peripheral blood. Conclusions: Ex vivo TKD/IL2-activated, autologous NK cells are well tolerated and deliver positive clinical responses in patients with advanced NSCLC after RCT.

Elevated Proportions of Activated Nk Cells at Diagnosis Predict a Favourable Prognosis in Glioblastoma Patients

“…Herein, we have shown that high cytosolic levels of Hsp70 are associated with a more aggressive glioma type, but extracellular Hsp70 levels might act as a DAMP to stimulate NK cells. This hypothesis is supported by promising data of phase I and II clinical trials using ex vivo Hsp70 peptide and IL-2 stimulated NK cells to treat patients with advanced colon and lung cancers after radiochemotherapy [13,14]. The stimulation of patient-derived, anergic NK cells with Hsp70 peptide plus IL-2, but not with IL-2 alone, significantly enhanced the cytolytic activity of NK cells against membrane Hsp70+ tumor cells [13], and favorable clinical responses in a randomized phase II clinical trial could be attributed to an increased prevalence of activated CD94+ NK cells [14] that are responsible for the interaction with Hsp70 [31].…”

“…Due to the smaller size, favorable biodistribution, higher purity and easier GMP-production the Hsp70-peptide TKD is advantageous to recombinant Hsp70 protein for stimulating of NK cells. A pilot [12] and clinical phase I study [13] demonstrated excellent safety profiles of ex vivo TKD/IL-2-activated, autologous NK cells, and patients with advanced NSCLC showed promising clinical responses in a randomized clinical phase II trial after adoptive transfer of ex vivo TKD/IL-2-activated NK cells [14]. Apart from a study in grade IV glioblastoma/astrocytoma patients [15] insight into the expression and localization of Hsp70 in different types of brain tumors and its impact on the prevalence and activity of NK cells is limited.…”

Heat Shock Proteins in Lymphoma Immunotherapy

“…HSP90 showed to affect CD3 and CD28, thus, the effect of HSP90 on CAR-containing CD3 and CD28-derived domains requires further investigation (133). From the other hand, HSP70-derived peptide TKD has been used for ex vivo activation of NK cells for adoptive transfer therapy and, since no severe toxicity was observed for NK-based immunotherapy, this strategy may be exploited for the development of lymphoma immunotherapy (140). In light of the reported, two research teams proposed to target membrane-bound HSP70 and HSP90 isoforms on tumors by CARs (134,136).…”

“…Chimeric Antigens Receptor (CAR) targeting CD19 and CD30 showed promising results in patients with r/r lymphoma (93,129,131,132). Autologous NK cells pre-activated with cytokines (IL-2, IL-15) and 14-mer HSP70-derived peptide (TKD) can be used for ex vivo activation of NK cells for the adoptive transfer therapy (137)(138)(139)(140). Anti-HSP70 and HSP90 CARs were proposed for specific targeting of membranebound forms of HSP70 and HSP90 (134,136).…”

“…Furthermore, they reported that NK cells pre-activated with TKD and IL-2 recognize mHSP70 on tumor cells (137). Translating this to clinical trial, Multhoff et al showed that four cycles of adoptive transfer of autologous NK cells prestimulated with TKD and IL-2 was well-tolerated and resulted in increase in the number of NK cells in peripheral blood of patients with mHSP70-positive non-small cell lung cancer (NSCLC) following radiochemotherapy in phase II clinical trial (140). Earlier, same research team demonstrated that NK cells activated with IL-2 and TKD and combined with anti-PD-1 antibody increased cytolytic activity of NK cells toward cancer cells and delayed tumor growth in vivo (162).…”