{"id":{"repo_id":"mit","oai_identifier":"oai:dspace.mit.edu:1721.1/144968"},"canonical_url":"https://search.dev.ndltd.org/etd/mit/oai:dspace.mit.edu:1721.1/144968","repository":{"repo_id":"mit","name":"MIT","base_url":"https://dspace.mit.edu/oai/request"},"display":{"title":"An Affinity Threshold for Maximum Efficacy in Anti-PD-1 Cancer Immunotherapy","abstract":"Monoclonal antibodies (mAbs) targeted to the programmed cell death protein 1 (PD-1) remain the most prevalent cancer immunotherapy both as a monotherapy and in combination with additional therapies. Despite the extensive success of anti-PD-1 mAbs in the clinic, the experimental relationship between binding affinity and functional potency for anti-PD-1 antibodies in vivo has not been reported. Two widely-used FDA-approved anti-PD-1 antibodies, nivolumab and pembrolizumab have similar single digit nanomolar equilibrium binding constants (KD). Anti-PD-1 antibodies with higher and lower affinity than nivolumab or pembrolizumab are entering the clinic and show varied pre-clinical efficacy. Here, we explore the role of broad-ranging affinity variation on efficacy within a single lineage in a syngeneic immunocompetent mouse model. Using yeast surface display and affinity maturation, we engineered a panel of murine anti-PD-1 antibodies with varying affinity (ranging from KD = 20 pM - 15 nM). A combination of equilibrium and kinetic sorting strategies was used to both improve and reduce the affinity of a parental anti-PD-1 clone, 29F.1A12. We characterized the affinity of the antibodies using a number of methods, including ELISA, off-rate bead assays, and bio-layer interferometry, to confirm the wide range of affinity. We also characterized the internalization rate and pharmacokinetic clearance rate of our antibodies to confirm a consistent drug profile aside from mPD-1 affinity. Using these experimentally-determined rates and literature values, we developed a physiologically-based pharmacokinetic (PBPK) model to complement the in vivo results and highlight the direct relationship between dose, affinity, and PD-1 target saturation in the tumor. Through in vivo efficacy studies using the MC38 murine adenocarcinoma model, we found that there is an affinity threshold required for maximum efficacy at a given dose of anti-PD-1 immunotherapy. We demonstrate that efficacy can be rescued by increasing the dose of a low affinity clone. Thus alternatively, we show that for a given affinity, there is a dose threshold required to achieve maximum efficacy. Ultimately, we conclude that the anti-PD-1 affinity/dose relationship supports a clear receptor-occupancy mechanism of action.","abstract_html":"Monoclonal antibodies (mAbs) targeted to the programmed cell death protein 1 (PD-1) remain the most prevalent cancer immunotherapy both as a monotherapy and in combination with additional therapies. Despite the extensive success of anti-PD-1 mAbs in the clinic, the experimental relationship between binding affinity and functional potency for anti-PD-1 antibodies in vivo has not been reported. Two widely-used FDA-approved anti-PD-1 antibodies, nivolumab and pembrolizumab have similar single digit nanomolar equilibrium binding constants (KD). Anti-PD-1 antibodies with higher and lower affinity than nivolumab or pembrolizumab are entering the clinic and show varied pre-clinical efficacy. Here, we explore the role of broad-ranging affinity variation on efficacy within a single lineage in a syngeneic immunocompetent mouse model. Using yeast surface display and affinity maturation, we engineered a panel of murine anti-PD-1 antibodies with varying affinity (ranging from KD = 20 pM - 15 nM). A combination of equilibrium and kinetic sorting strategies was used to both improve and reduce the affinity of a parental anti-PD-1 clone, 29F.1A12. We characterized the affinity of the antibodies using a number of methods, including ELISA, off-rate bead assays, and bio-layer interferometry, to confirm the wide range of affinity. We also characterized the internalization rate and pharmacokinetic clearance rate of our antibodies to confirm a consistent drug profile aside from mPD-1 affinity. Using these experimentally-determined rates and literature values, we developed a physiologically-based pharmacokinetic (PBPK) model to complement the in vivo results and highlight the direct relationship between dose, affinity, and PD-1 target saturation in the tumor. Through in vivo efficacy studies using the MC38 murine adenocarcinoma model, we found that there is an affinity threshold required for maximum efficacy at a given dose of anti-PD-1 immunotherapy. We demonstrate that efficacy can be rescued by increasing the dose of a low affinity clone. Thus alternatively, we show that for a given affinity, there is a dose threshold required to achieve maximum efficacy. Ultimately, we conclude that the anti-PD-1 affinity/dose relationship supports a clear receptor-occupancy mechanism of action.","abstract_has_math":false,"creators":["Cowles, Sarah Clare"],"institution":"Massachusetts Institute of Technology","degree_name":"Doctoral","degree_level":null,"degree_discipline":null,"degree_department":"Massachusetts Institute of Technology. Department of Chemical Engineering","school":null,"contributors":[],"advisors":["Wittrup, K. Dane"],"committee_chairs":[],"committee_members":[],"year":2022,"date_issued":"2022-05","date_published":"2022-05","updated_at":"2026-07-22T22:21:50Z","subjects":[],"languages":[],"rights":["In Copyright - Educational Use Permitted","Copyright MIT"],"rights_urls":["http://rightsstatements.org/page/InC-EDU/1.0/"],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/1721.1/144968","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Wittrup, K. Dane"]},{"key":"dc:contributor.department","label":"Department","values":["Massachusetts Institute of Technology. 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Despite the extensive success of anti-PD-1 mAbs in the clinic, the experimental relationship between binding affinity and functional potency for anti-PD-1 antibodies in vivo has not been reported. Two widely-used FDA-approved anti-PD-1 antibodies, nivolumab and pembrolizumab have similar single digit nanomolar equilibrium binding constants (KD). Anti-PD-1 antibodies with higher and lower affinity than nivolumab or pembrolizumab are entering the clinic and show varied pre-clinical efficacy. Here, we explore the role of broad-ranging affinity variation on efficacy within a single lineage in a syngeneic immunocompetent mouse model. Using yeast surface display and affinity maturation, we engineered a panel of murine anti-PD-1 antibodies with varying affinity (ranging from KD = 20 pM - 15 nM). A combination of equilibrium and kinetic sorting strategies was used to both improve and reduce the affinity of a parental anti-PD-1 clone, 29F.1A12. We characterized the affinity of the antibodies using a number of methods, including ELISA, off-rate bead assays, and bio-layer interferometry, to confirm the wide range of affinity. We also characterized the internalization rate and pharmacokinetic clearance rate of our antibodies to confirm a consistent drug profile aside from mPD-1 affinity. Using these experimentally-determined rates and literature values, we developed a physiologically-based pharmacokinetic (PBPK) model to complement the in vivo results and highlight the direct relationship between dose, affinity, and PD-1 target saturation in the tumor. Through in vivo efficacy studies using the MC38 murine adenocarcinoma model, we found that there is an affinity threshold required for maximum efficacy at a given dose of anti-PD-1 immunotherapy. We demonstrate that efficacy can be rescued by increasing the dose of a low affinity clone. Thus alternatively, we show that for a given affinity, there is a dose threshold required to achieve maximum efficacy. Ultimately, we conclude that the anti-PD-1 affinity/dose relationship supports a clear receptor-occupancy mechanism of action."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Ph.D."]},{"key":"dc:title","label":"Title","values":["An Affinity Threshold for Maximum Efficacy in Anti-PD-1 Cancer Immunotherapy"]}]}],"canonical_facts":{"dc:contributor.advisor":["Wittrup, K. Dane"],"dc:contributor.department":["Massachusetts Institute of Technology. Department of Chemical Engineering"],"dc:creator":["Cowles, Sarah Clare"],"dc:date.accessioned":["2022-08-29T16:24:16Z"],"dc:date.available":["2022-08-29T16:24:16Z"],"dc:date.issued":["2022-05"],"dc:description.abstract":["Monoclonal antibodies (mAbs) targeted to the programmed cell death protein 1 (PD-1) remain the most prevalent cancer immunotherapy both as a monotherapy and in combination with additional therapies. Despite the extensive success of anti-PD-1 mAbs in the clinic, the experimental relationship between binding affinity and functional potency for anti-PD-1 antibodies in vivo has not been reported. Two widely-used FDA-approved anti-PD-1 antibodies, nivolumab and pembrolizumab have similar single digit nanomolar equilibrium binding constants (KD). Anti-PD-1 antibodies with higher and lower affinity than nivolumab or pembrolizumab are entering the clinic and show varied pre-clinical efficacy. Here, we explore the role of broad-ranging affinity variation on efficacy within a single lineage in a syngeneic immunocompetent mouse model. Using yeast surface display and affinity maturation, we engineered a panel of murine anti-PD-1 antibodies with varying affinity (ranging from KD = 20 pM - 15 nM). A combination of equilibrium and kinetic sorting strategies was used to both improve and reduce the affinity of a parental anti-PD-1 clone, 29F.1A12. We characterized the affinity of the antibodies using a number of methods, including ELISA, off-rate bead assays, and bio-layer interferometry, to confirm the wide range of affinity. We also characterized the internalization rate and pharmacokinetic clearance rate of our antibodies to confirm a consistent drug profile aside from mPD-1 affinity. Using these experimentally-determined rates and literature values, we developed a physiologically-based pharmacokinetic (PBPK) model to complement the in vivo results and highlight the direct relationship between dose, affinity, and PD-1 target saturation in the tumor. Through in vivo efficacy studies using the MC38 murine adenocarcinoma model, we found that there is an affinity threshold required for maximum efficacy at a given dose of anti-PD-1 immunotherapy. We demonstrate that efficacy can be rescued by increasing the dose of a low affinity clone. Thus alternatively, we show that for a given affinity, there is a dose threshold required to achieve maximum efficacy. Ultimately, we conclude that the anti-PD-1 affinity/dose relationship supports a clear receptor-occupancy mechanism of action."],"dc:description.degree":["Ph.D."],"dc:identifier.uri":["https://hdl.handle.net/1721.1/144968"],"dc:publisher":["Massachusetts Institute of Technology"],"dc:rights":["In Copyright - Educational Use Permitted","Copyright MIT"],"dc:rights.uri":["http://rightsstatements.org/page/InC-EDU/1.0/"],"dc:title":["An Affinity Threshold for Maximum Efficacy in Anti-PD-1 Cancer Immunotherapy"],"dc:type":["Thesis"],"thesis:degree_name":["Doctoral","Doctor of Philosophy"]},"updated_at":"2026-07-22T22:21:50Z"}