Arutselvan Natarajan1, Aaron T Mayer1,2, Robert E Reeves1, Claude M Nagamine3, Sanjiv Sam Gambhir4,5,6,7. 1. Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA. 2. Department of Bioengineering, Stanford University, Stanford, CA, USA. 3. Department of Comparative Medicine, Stanford University, Stanford, CA, USA. 4. Department of Radiology, School of Medicine, Stanford University, Stanford, CA, USA. sgambhir@stanford.edu. 5. Department of Bioengineering, Stanford University, Stanford, CA, USA. sgambhir@stanford.edu. 6. Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA. sgambhir@stanford.edu. 7. Molecular Imaging Program at Stanford, Department of Radiology, Stanford University, James H. Clark Center, 318 Campus Drive, E153, Stanford, CA, 94305, USA. sgambhir@stanford.edu.
Abstract
PURPOSE: It is well known that cancers exploit immune checkpoints (programmed death 1 receptor (PD-1) and its ligand (PD-L1)) to evade anti-tumor immune responses. Although immune checkpoint (IC) blockade is a promising approach, not all patients respond. Hence, imaging of tumor-infiltrating lymphocytes (TILs) is of high specific interest, as they are known to express PD-1 during activation and subsequent exhaustion in the tumor microenvironment and are thought to be potentially predictive of therapeutic responses to IC blockade. PROCEDURES: We developed immune-tracers for positron emission tomography (PET) to image hPD-1 status of human peripheral blood mononuclear cells (hPBMCs) adoptively transferred to NOD-scid IL-2Rγnull (NSG) mice (hNSG) bearing A375 human skin melanoma tumors. The anti-PD-1 human antibody (IgG; keytruda) was labeled with either Zr-89 or Cu-64 radiometals to image PD-1-expressing human TILs in vivo. RESULTS: [89Zr] Keytruda (groups = 2; NSG-ctl (control) and hNSG-nblk (non-blocking), n = 3-5, 3.2 ± 0.4 MBq/15-16 μg/200 μl) and [64Cu] Keytruda (groups = 3; NSG-ctl, NSG-blk (blocking), and hNSG-nblk; n = 4, 7.4 ± 0.4 MBq /20-25 μg/200 μl) were administered in mice. PET-CT scans were performed over 1-144 h ([89Zr] Keytruda) and 1-48 h ([64Cu] Keytruda) on mice. hNSG mice exhibited a high tracer uptake in the spleen, lymphoid organs and tumors. At 24 h, human TILs homing into melanoma of hNSG-nblk mice exhibited high signal (mean %ID/g ± SD) of 3.8 ± 0.4 ([89Zr] Keytruda), and 6.4 ± 0.7 ([64Cu] Keytruda), which was 1.5- and 3-fold higher uptake compared to NSG-ctl mice (p = 0.01), respectively. Biodistribution measurements of hNSG-nblk mice performed at 144 h ([89Zr] Keytruda) and 48 h ([64Cu] Keytruda) p.i. revealed tumor to muscle ratios as high as 45- and 12-fold, respectively. CONCLUSIONS: Our immunoPET study clearly demonstrates specific imaging of human PD-1-expressing TILs within the tumor and lymphoid tissues. This suggests these anti-human-PD-1 tracers could be clinically translatable to monitor cancer treatment response to IC blockade therapy.
PURPOSE: It is well known that cancers exploit immune checkpoints (programmed death 1 receptor (PD-1) and its ligand (PD-L1)) to evade anti-tumor immune responses. Although immune checkpoint (IC) blockade is a promising approach, not all patients respond. Hence, imaging of tumor-infiltrating lymphocytes (TILs) is of high specific interest, as they are known to express PD-1 during activation and subsequent exhaustion in the tumor microenvironment and are thought to be potentially predictive of therapeutic responses to IC blockade. PROCEDURES: We developed immune-tracers for positron emission tomography (PET) to image hPD-1 status of human peripheral blood mononuclear cells (hPBMCs) adoptively transferred to NOD-scid IL-2Rγnull (NSG) mice (hNSG) bearing A375 humanskin melanoma tumors. The anti-PD-1human antibody (IgG; keytruda) was labeled with either Zr-89 or Cu-64 radiometals to image PD-1-expressing human TILs in vivo. RESULTS: [89Zr] Keytruda (groups = 2; NSG-ctl (control) and hNSG-nblk (non-blocking), n = 3-5, 3.2 ± 0.4 MBq/15-16 μg/200 μl) and [64Cu] Keytruda (groups = 3; NSG-ctl, NSG-blk (blocking), and hNSG-nblk; n = 4, 7.4 ± 0.4 MBq /20-25 μg/200 μl) were administered in mice. PET-CT scans were performed over 1-144 h ([89Zr] Keytruda) and 1-48 h ([64Cu] Keytruda) on mice. hNSG mice exhibited a high tracer uptake in the spleen, lymphoid organs and tumors. At 24 h, human TILs homing into melanoma of hNSG-nblk mice exhibited high signal (mean %ID/g ± SD) of 3.8 ± 0.4 ([89Zr] Keytruda), and 6.4 ± 0.7 ([64Cu] Keytruda), which was 1.5- and 3-fold higher uptake compared to NSG-ctl mice (p = 0.01), respectively. Biodistribution measurements of hNSG-nblk mice performed at 144 h ([89Zr] Keytruda) and 48 h ([64Cu] Keytruda) p.i. revealed tumor to muscle ratios as high as 45- and 12-fold, respectively. CONCLUSIONS: Our immunoPET study clearly demonstrates specific imaging of humanPD-1-expressing TILs within the tumor and lymphoid tissues. This suggests these anti-human-PD-1 tracers could be clinically translatable to monitor cancer treatment response to IC blockade therapy.
Authors: David F McDermott; Charles G Drake; Mario Sznol; Toni K Choueiri; John D Powderly; David C Smith; Julie R Brahmer; Richard D Carvajal; Hans J Hammers; Igor Puzanov; F Stephen Hodi; Harriet M Kluger; Suzanne L Topalian; Drew M Pardoll; Jon M Wigginton; Georgia D Kollia; Ashok Gupta; Dan McDonald; Vindira Sankar; Jeffrey A Sosman; Michael B Atkins Journal: J Clin Oncol Date: 2015-03-30 Impact factor: 44.544
Authors: Caroline Robert; Antoni Ribas; Jedd D Wolchok; F Stephen Hodi; Omid Hamid; Richard Kefford; Jeffrey S Weber; Anthony M Joshua; Wen-Jen Hwu; Tara C Gangadhar; Amita Patnaik; Roxana Dronca; Hassane Zarour; Richard W Joseph; Peter Boasberg; Bartosz Chmielowski; Christine Mateus; Michael A Postow; Kevin Gergich; Jeroen Elassaiss-Schaap; Xiaoyun Nicole Li; Robert Iannone; Scot W Ebbinghaus; S Peter Kang; Adil Daud Journal: Lancet Date: 2014-07-15 Impact factor: 79.321
Authors: Mojgan Ahmadzadeh; Laura A Johnson; Bianca Heemskerk; John R Wunderlich; Mark E Dudley; Donald E White; Steven A Rosenberg Journal: Blood Date: 2009-05-07 Impact factor: 22.113
Authors: Jedd D Wolchok; Harriet Kluger; Margaret K Callahan; Michael A Postow; Naiyer A Rizvi; Alexander M Lesokhin; Neil H Segal; Charlotte E Ariyan; Ruth-Ann Gordon; Kathleen Reed; Matthew M Burke; Anne Caldwell; Stephanie A Kronenberg; Blessing U Agunwamba; Xiaoling Zhang; Israel Lowy; Hector David Inzunza; William Feely; Christine E Horak; Quan Hong; Alan J Korman; Jon M Wigginton; Ashok Gupta; Mario Sznol Journal: N Engl J Med Date: 2013-06-02 Impact factor: 91.245
Authors: Leila Khoja; Marcus O Butler; S Peter Kang; Scot Ebbinghaus; Anthony M Joshua Journal: J Immunother Cancer Date: 2015-08-18 Impact factor: 13.751
Authors: Haley L Wissler; Emily B Ehlerding; Zhigang Lyu; Yue Zhao; Si Zhang; Anisa Eshraghi; Zakey Yusuf Buuh; Jeffrey C McGuth; Yifu Guan; Jonathan W Engle; Sarah J Bartlett; Vincent A Voelz; Weibo Cai; Rongsheng E Wang Journal: Mol Pharm Date: 2019-03-25 Impact factor: 4.939
Authors: Daniel J Rubins; Xiangjun Meng; Paul McQuade; Michael Klimas; Krista Getty; Shu-An Lin; Brett M Connolly; Stacey S O'Malley; Hyking Haley; Mona Purcell; Liza Gantert; Marie Holahan; Joel Lindgren; Pär Eklund; Caroline Ekblad; Fredrik Y Frejd; Eric D Hostetler; Dinko E González Trotter; Jeffrey L Evelhoch Journal: Mol Imaging Biol Date: 2020-10-23 Impact factor: 3.488