Pharmacodynamic results

Treg Depletion and/or Inhibition

Last updated: 2026-04-27   Rows: 51 across 44 studies   Outcomes: 19 succeeded / 9 partial / 12 failed / 11 not-assessed (ratio-shift)

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All PBMC tumor TDLN bone marrow ascites skin other
InterventionDiseaseNReportTissueAssayTreg changeResultConfidenceBias & confoundingSourcePMIDDesignDose/scheduleTreg defnReadoutTimepointTiming detailBaselinePostMagnitudeSignificanceDurabilityIntentData sourceNotes
Denileukin diftitox (ONTAK)Metastatic melanoma13
Attia P ··· Rosenberg SA
J Immunother, 2005
PBMCflow≈ n.s.null result
null
ModerateLow
small-nunderpowered
PMID PMCID DOI critique16224276paired-pre-postVariable per prior dosing schedulesCD4+CD25+FOXP3+frequency-of-CD4early-on-treatmentpost-dose serial samplingNot reported in cells/µL; FoxP3 mRNA expression (copies/10^3 β-actin) onlyFoxP3 mRNA change (cycle 1): 9 µg/kg cohort −1.27±2.57 (p=0.656, n=4); 18 µg/kg cohort −2.01±0.618 (p=0.031, n=5); pooled −1.68±1.11 (p=0.167, n=9); after ≥4 cycles (n=4) −3.30±3.21 (p=0.380)Small, dose-dependent FoxP3 mRNA reduction; no elimination of CD4+CD25+ cells; suppressive function preserved (50.6-98.2% suppression retained in 5 patients post-cycle-2)p=0.031 (18 µg/kg only); pooled n.s.mechanism-targetedpmc_full_textAttia 2005 — key null result: DAB/IL-2 failed to eliminate functional Tregs in melanoma. Full-text backfill 2026-04-23: statistically significant FoxP3 mRNA decrease only in 18 µg/kg cohort (p=0.031), pooled analysis n.s. (p=0.167); in vitro suppression retained in 5/5 patients (50.6-98.2%). Conflicts with Dannull 2005 (16308572): Dannull saw d4 functional abrogation in RCC while Attia saw preserved suppression post-cycle-2 in melanoma; gating (FOXP3+ vs CD4+CD25+) and timepoint differences likely reconcile.
Denileukin diftitox (DAB389IL-2) prior to RCC tumor-RNA DC vaccineAutologous RCC tumor-RNA dendritic cell vaccineMetastatic renal cell carcinoma11
Dannull J ··· Vieweg J
J Clin Invest, 2005
PBMCflow+fn↓ −51%significant reduction
depletion
LowModerate
cd25-gating-confoundsmall-nno-multiplicity-correction
PMID PMCID DOI critique16308572paired-pre-postSingle infusion prior to vaccinationCD4+CD25+ (functional Treg assay)frequency-of-CD4early-on-treatmentpre- and post-denileukin diftitox; then post-vaccine2.5-4.6% CD4+CD25high/FoxP3+ of CD4+ (2.1±1.2-fold above healthy volunteers n=10)26-76% relative reduction of CD4+CD25high Tregs at day 4 post-DAB389IL-2 (all 7 subjects analyzed)26-76% reduction in CD4+CD25high; FoxP3 mRNA reduced ~30-80% within purified CD4+ cells at day 4reported significant (all 7 subjects)Transient: ~75% of Tregs restored within 2 months (d4 nadir, d60 recovery)mechanism-targetedpmc_full_textDannull 2005 JCI — first clear demonstration that DAB389IL-2 depletes functional Tregs in cancer patients and enhances vaccine response. Full-text backfill 2026-04-23: explicit 26-76% range for frequency reduction, 30-80% for FoxP3 mRNA, nadir d4, 75% recovery by 2 months, suppressive function abrogated.
Low-dose oral cyclophosphamide (metronomic)Advanced end-stage solid cancers9
Ghiringhelli F ··· Chauffert B
Cancer Immunol Immunother, 2007
PBMCflow↓ −61%significant reduction
depletion
ModerateModerate
very-small-nsingle-arm-no-control
PMID PMCID DOI critique16960692paired-pre-post50 mg PO twice daily, 1 week on / 1 week offCD4+CD25highFOXP3+frequency-of-CD4early-on-treatmentafter 1 month (day 28-ish)7.9 ± 1.5% (CD4+CD25high of CD4+); 28.7 ± 9.4 cells/mm3 (absolute)3.1 ± 1.8% (CD4+CD25high of CD4+); 6.4 ± 5.4 cells/mm3 (absolute) at 1 month~61% reduction in frequency (7.9% to 3.1%) and ~78% reduction in absolute count (28.7 to 6.4 cells/mm3)p<0.0001 (both frequency and absolute count)Maintained during metronomic dosing; 2/2 patients with extended follow-up had Treg return to pretreatment levels ~2 months after stopping CTXmechanism-targetedpmc_full_textLandmark Ghiringhelli 2007 metronomic-cyclo PD paper. Full-text backfill 2026-04-23: explicit mean±SD frequency and absolute count values, p<0.0001 for both, functional recovery data, 2-month off-treatment recovery. Side-list Ghiringhelli 2004 preclinical excluded from table.
Daclizumab (anti-CD25)Metastatic melanoma8
Mahnke K ··· Enk AH
Int J Cancer, 2007
PBMCflow↓ sig.significant reduction
depletion
LowModerate
cd25-gating-confoundabstract-onlyvery-small-nsurface-marker-gating
PMID DOI critique17315189paired-pre-postSingle bolus, then successiveCD4+CD25+ (FOXP3-validated in subset)frequency-of-CD4early-on-treatmentimmediately post-first bolus through day 13significantly reduced; successive doses further reducedreported significantRecovery observed over ~13 days after single dose; sustained with repeated dosingmechanism-targetedpubmed_abstractMahnke 2007 — daclizumab Treg depletion kinetics. Full-text backfill 2026-04-23: not openly accessible (Int J Cancer, inEPMC=N, subscription required). Abstract-only values retained: significant PBMC Treg reduction after single bolus, sustained with repeat dosing, ~13-day recovery window.
Single IV cyclophosphamide + intratumoral BCGIntratumoral BCG (non-specific immunotherapy)Metastatic solid cancer (mixed)49
Audia S ··· Bonnotte B
Clin Exp Immunol, 2007
PBMCflow≈ n.s.null result
null
LowModerate
abstract-onlysurface-marker-gating
PMID critique17956583treated-vs-untreatedSingle IV dose (300 mg/m2 per paper)CD4+CD25+ (FoxP3 referenced)frequency-of-CD4early-on-treatmentpost-infusion serial9.2%not significantly changedbaseline 9.2% (patients) vs 7.1% (healthy) — post-cyclo: no significant modulationn.s.mechanism-targetedpubmed_abstractAudia 2007 — single-dose IV cyclo + BCG failed to modulate Treg numbers or function despite elevated baseline in cancer patients. Important null result anchoring the 'dose schedule matters' argument. Full-text backfill 2026-04-23: article not openly accessible (not in PMC, Europe PMC inEPMC=N, subscription required). Abstract-derived baseline 9.2% vs 7.1% healthy and 'no significant modulation' remains the only numeric available.
TremelimumabMelanoma13
Comin-Anduix B ··· Ribas A
J Transl Med, 2008
PBMCflow≈ n.s.null result
null
ModerateModerate
small-nno-multiplicity-correctionindustry-sponsored
PMID PMCID DOI critique18452610paired-pre-postPer trialCD4+CD25highFOXP3+frequency-of-CD4early-on-treatmentSerial post-infusionFoxP3 mRNA pre-dose (qPCR); per-patient values not tabulatedNo statistically significant change between pre- and post-dosing FoxP3 mRNA (n=8 evaluable of 13)No significant change in FoxP3 mRNA pre→post; insufficient cells for functional suppression assayn.s. (p-value not stated)exploratory-but-prespecifiedpmc_full_textComin-Anduix 2008 — PBMC PD of tremelimumab. Full-text backfill 2026-04-23: n=8 with baseline+follow-up FoxP3 mRNA data; 'failed to detect a statistically significant change (either positive or negative)'; Treg functional assay not performed due to insufficient cells from 40 mL draws.
Daclizumab (anti-CD25) prior to CEA-based cancer vaccineCEA-targeted cancer vaccineAdvanced CEA-expressing cancers (mixed solid)15
Morse MA ··· Clay TM
Blood, 2008
PBMCflow↓ sig.significant reduction
depletion
ModerateModerate
cd25-gating-confoundsmall-nschedule-dependent
PMID PMCID DOI critique18519811paired-pre-postMultiple dosesCD4+CD25highFoxP3+frequency-of-CD4early-on-treatmentpre- and post- multi-dose daclizumab; then post-vaccineBaseline CD4+CD25highFoxP3+ frequency (absolute µL count) not tabulated; per-patient trajectories shown in figuresCohort 2 (multi-dose, n=4): all 4 patients had lower Treg % at study end; Cohort 1 (single-dose, n=5): only 2/5 reducedDose-schedule dependent: multi-dose DD → 4/4 reduction; single-dose DD → 2/5 reduction; absolute Treg counts per µL began declining at week 5 and continued after final vaccination (Cohort 2 only)Time-to-first immune response p=0.003 (Cohort 2 vs Cohort 0); individual Treg p-values not reportedMulti-dose sustained decline through post-vaccine follow-up; single-dose reboundedmechanism-targetedpmc_full_textMorse 2008 Blood — pilot vaccine study. Full-text backfill 2026-04-23: schedule-dependent depletion confirmed (4/4 multi-dose vs 2/5 single-dose reduced Treg%); absolute µL counts only in Cohort 2. No tabulated baseline/post numeric means. Conflict pair with Luke 2016 (27330808): both show single-dose DD fails; Morse shows multi-dose DD succeeds — not a true conflict but a schedule-dependence finding.
Ipilimumab or tremelimumabMelanoma11
Ribas A ··· Cochran AJ
Clin Cancer Res, 2009
tumorflow≈ n.s.null result
null
LowSerious
retrospective-analysisfoxp3-ihc-single-markerabstract-onlyvery-small-n+1
PMID DOI critique19118070paired-pre-postPer trialFoxP3+frequency-of-lymphocytesearly-on-treatmentPost-dose biopsyNo consistent FoxP3 reduction post-CTLA-4 blockaden.s.exploratory-but-prespecifiedpubmed_abstractRibas 2009 — intratumoral FoxP3/IDO in CTLA-4 blockade. Full-text backfill 2026-04-23: Clin Cancer Res article not in Europe PMC OA (inEPMC=N, subscription required). Abstract retains qualitative 'no consistent FoxP3 reduction' finding supporting early null-for-intratumoral-depletion; numeric values not extractable.
Denileukin diftitox (DD) + high-dose IL-2High-dose IL-2Metastatic renal cell carcinoma18
Atchison E ··· Kuzel TM
J Immunother, 2010
PBMCflow↓ −56.3%significant reduction
depletion
LowSerious
cd25-gating-confoundabstract-onlysurface-marker-gatingretrospective-analysis+1
PMID DOI critique20664355paired-pre-postGroups A/B/C dose-escalationCD4+CD25+frequency-of-CD4early-on-treatmentpre-DD to post-DD, serialmedian 56.3% reduction from pre-DD to post-DDp=0.013mechanism-targetedpubmed_abstractAtchison 2010 pilot. Clean median 56.3% reduction from pre-DD to post-DD, p=0.013 (abstract-reported). Full-text backfill 2026-04-23: article not openly accessible (J Immunother, inEPMC=N, subscription required); abstract numeric retained as sole source.
Tremelimumab (anti-CTLA-4)Metastatic melanoma18
Huang RR ··· Ribas A
Clin Cancer Res, 2011
tumorflow↑ +375%increase
null
ModerateModerate
foxp3-ihc-single-markersmall-nno-multiplicity-correctionauthor-coi-sponsor
PMID PMCID DOI critique21558401paired-pre-postPer trial scheduleFOXP3+frequency-of-lymphocytesearly-on-treatmentPost-dose biopsy35.20 ± 30.06 FOXP3+ cells/mm^2 (n=19 paired)167.35 ± 162.37 FOXP3+ cells/mm^2 post-dosingMean +132.15 cells/mm^2 (~4.75× INCREASE) in FOXP3+ density; CR patients 993.76±734.18 vs PD 775.63±458.70 (n.s. p=0.3340)p=0.0029 (paired Mann-Whitney; note: paper uses paired test despite Mann-Whitney label)mechanism-targetedpmc_full_textHuang 2011 — tremelimumab INCREASED rather than depleted intratumoral FOXP3+ cells. Full-text backfill 2026-04-23: baseline 35.2 → post 167.4 cells/mm^2 (p=0.0029, paired, n=19). Classic early null-for-intratumoral-Treg-depletion result supporting Sharma 2019's broader conclusion.
Ipilimumab (in patients with severe enterocolitis)Melanoma (with ipi-induced enterocolitis)4
Nancey S ··· Flourié B
Inflamm Bowel Dis, 2012
otherflow↓ qual.significant reduction
depletion
Very lownot amenable — case report
case-report-n-of-fewabstract-onlyspin-abstract-vs-results
PMID DOI critique22069060case-seriesPer trialFoxP3+frequency-of-lymphocyteslateAt time of colitis flareProfound long-lasting FoxP3+ Treg depletion in colonic mucosareportedLong-lastingincidental-but-measuredpubmed_abstractNancey 2012 — ipi-enterocolitis colonic mucosa Treg depletion. Full-text backfill 2026-04-23: Inflamm Bowel Dis article not in Europe PMC OA (inEPMC=N, subscription required). Abstract retains 'profound long-lasting FoxP3+ Treg depletion' in lamina propria; numeric density values not extractable from abstract.
IpilimumabAdvanced melanoma (stage III/IV)82
Hamid O ··· Berman D
J Transl Med, 2011
tumorflownull result
null
LowModerate
exploratory-endpointno-multiplicity-correctionindustry-sponsored
PMID PMCID DOI critique22123319paired-pre-postPer trialFoxP3+frequency-of-lymphocytesearly-on-treatmentBaseline vs week 3 (24-72h post-dose 2)Benefit group: FoxP3 detected in 75.0% of evaluable pretreatment biopsies; Non-benefit group: 36.0%Longitudinal change not quantified — paper reports baseline FoxP3 only as predictive biomarkerNot a depletion study; baseline FoxP3 positivity associated with clinical benefit (OR ~10.38, p=0.014); TIL increase post-dose separate finding (p=0.005)p=0.014 (baseline FoxP3 vs clinical benefit); not a post-treatment-change p-valueincidental-but-measuredpmc_full_textHamid 2011 — predictive biomarker study, NOT a depletion endpoint. Full-text backfill 2026-04-23 confirmed: FoxP3 quantified only at baseline (pretreatment biopsy), not longitudinally; 24-72h post-dose-2 samples collected but FoxP3 change not quantified. Reclassified intent_to_deplete from 'exploratory-but-prespecified' to 'incidental-but-measured' — the study did not aim to measure Treg depletion. Retained in table because it still reports a Treg-related readout in melanoma ipi patients.
Azacitidine + panobinostatazacitidine (DNMTi) + panobinostat (HDACi)Acute myeloid leukemia14
Govindaraj C ··· Plebanski M
Clin Cancer Res, 2014
PBMCflow↓ sig.significant reduction
depletion
ModerateModerate
abstract-onlysmall-n
PMID DOI critique24297862paired-pre-postpanobinostat + azacitidine 28-day cycles (dose not specified in abstract)CD4+CD25hi FOXP3+ TNFR2+ subsetfrequency-of-CD4midafter 28-day cycle(s) of aza+panoelevated vs healthy donors (TNFR2+ Treg subset)decreased in vivo after aza+panoTNFR2+ Treg reduction (no numeric % given in abstract)reported significant; associated with increased IFN-γ, IL-2 and clinical benefitmeasured within 28-day cyclespre-specified-endpointpubmed_abstractGovindaraj 2014 CCR. Abstract-only — no PMC record (non-OA in 2014 CCR). The reduction is specifically in TNFR2+ Treg subset, not total FoxP3+ Tregs. Panobinostat identified as the primary Treg-reducing agent in combination. Important conceptual anchor for HDACi-driven Treg-subset targeting in AML.
Azacitidine + panobinostatazacitidine (DNMTi) + panobinostat (HDACi)Acute myeloid leukemia14
Govindaraj C ··· Plebanski M
Clin Cancer Res, 2014
bone-marrowflow↓ sig.significant reduction
depletion
ModerateModerate
abstract-onlysmall-n
PMID DOI critique24297862paired-pre-postpanobinostat + azacitidine 28-day cycles (dose not specified in abstract)CD4+CD25hi FOXP3+ TNFR2+ subsetfrequency-of-CD4midafter 28-day cycle(s) of aza+panoelevated vs healthy donors, high BM-migration potentialdecreased in vivo after aza+panoTNFR2+ Treg reduction in bone marrow (no numeric % in abstract)reported significant; associated with increased IFN-γ, IL-2 in bone marrow effector T cellspre-specified-endpointpubmed_abstractGovindaraj 2014 CCR — bone-marrow companion row to the PBMC row. Same caveats: abstract-only, no numerics, TNFR2+ subset not total FoxP3+.
Single-dose denileukin diftitox + gp100:209-217(210M) peptide vaccinegp100:209-217(210M) peptide vaccine + IFA + IL-2Advanced melanoma60
Luke JJ ··· Gajewski TF
J Immunother Cancer, 2016
PBMCflow≈ n.s.null result
null
LowModerate
cd25-gating-confoundindustry-sponsored
PMID PMCID DOI critique27330808randomized-controlledSingle dose pre-vaccineCD4+CD25highFoxP3+frequency-of-CD4early-on-treatmentpre-vaccine post-DDNot numerically reported; individual patient data shown in Fig 2 without quantificationNot reproducibly reduced; frequencies similar to control patientsNo reproducible reduction in peripheral Treg numbers; 1/1 evaluable paired tumor biopsy (patient 16) showed INCREASED FoxP3 transcripts post-DDn.s. (no depletion)mechanism-targetedpmc_full_textLuke 2016 RCT — single-dose DD failed to deplete Tregs or enhance vaccine responses. Full-text backfill 2026-04-23: no numeric baseline/post Treg values in text (Fig 2 unquantified); 1 paired tumor biopsy showed INCREASED intratumoral FoxP3 post-DD. Conflict pair with Morse 2008 (18519811): Luke=single-dose→fail; Morse=multi-dose→succeed. Reconciled by schedule dependence, not truly conflicting.
Entinostat + high-dose IL-2entinostat (HDACi, class I) + high-dose IL-2Metastatic clear-cell renal cell carcinoma12
Pili R ··· Carducci MA
Clin Cancer Res, 2017
PBMCflow↓ sig.nonsignificant trend
depletion
ModerateSome concerns
surface-marker-gatingno-multiplicity-correctionindustry-sponsored
PMID PMCID DOI NCT critique28939740paired-pre-postentinostat oral priming C1D-14 through C1D1; HD IL-2 standardCD4+CD25hi T cellsfrequency-of-CD4early-on-treatmentC1D1 (post-priming entinostat, pre-IL-2)pretreatment CD4+CD25hi frequency (not numeric in manuscript)statistically significant decline in responders (n=5) vs progressors (n=7)Treg frequency lower at C1D1 in responders (p=0.0273)p=0.0273 responders lower than progressors at C1D1; p=0.03 lower Treg overall associated with responsemeasured across priming phase only (2 weeks entinostat)mechanism-targetedpmc_full_textPili 2017 CCR. PMC full text (PMC5712266). Class I HDACi entinostat was explicitly selected to downregulate FOXP3 and Treg suppressive function (preclinical rationale). Clinical data show a modest response-associated Treg decline, but absolute numerics are not reported for the whole cohort — only 12 of 47 had complete Treg samples. Design: priming phase (entinostat alone for 2 weeks) then combined with HD IL-2.
Entinostat + high-dose IL-2entinostat (HDACi, class I) + high-dose IL-2Metastatic clear-cell renal cell carcinoma3
Pili R ··· Carducci MA
Clin Cancer Res, 2017
tumorflowmixednonsignificant trend
depletion
ModerateSome concerns
surface-marker-gatingno-multiplicity-correctionindustry-sponsored
PMID PMCID DOI NCT critique28939740paired-pre-postentinostat oral priming C1D-14 through C1D1; HD IL-2 standardCD4+FOXP3+ (IHC)otherearly-on-treatmentpost-entinostat 2-week priming; before HD IL-2pretreatment tumor Treg infiltrationstable or decreased Treg infiltration in 3 paired biopsiesstable or decreased (no quantitative increase despite HD IL-2 co-administration)not testedmechanism-targetedpmc_full_textPili 2017 CCR — tumor biopsy companion row, N=3 only. Value of row is that HD IL-2 alone is known to expand Tregs; entinostat priming prevented that expansion in the intratumoral compartment. Not statistically powered.
Neoadjuvant chemotherapy + ipilimumabNeoadjuvant chemotherapy + ipilimumabEarly-stage NSCLC (IB-IIIA)24
Yi JS ··· Weinhold KJ
Clin Cancer Res, 2017
PBMCflow↑ sig.increase
null
LowModerate
small-npbmc-only-generalizedno-multiplicity-correction
PMID PMCID DOI critique28951518window-of-opportunityPer trialCD4+FOXP3+frequency-of-CD4early-on-treatmentBaseline vs post-neoadjuvantPer-patient baseline; aggregate not tabulatedMedian frequency of CD4+CD25+FOXP3+ Tregs increased slightly by 1.05% (V1 chemo-alone to V3 post-ipi)Median +1.05% absolute increase in Treg frequency from V1 to V3 (statistically significant but biologically modest); CTLA-4+ Tregs unchangedp=0.012 (Wilcoxon signed-rank)exploratory-but-prespecifiedpmc_full_textYi 2017 — ipi+chemo neoadj NSCLC. Full-text backfill 2026-04-23: median +1.05% Treg frequency increase post-ipi (p=0.012, statistically significant but tiny magnitude and opposite direction from depletion); CTLA-4+ Treg subset unchanged.
Neoadjuvant chemotherapy + ipilimumabNeoadjuvant chemotherapy + ipilimumabEarly-stage NSCLC (IB-IIIA)7
Yi JS ··· Weinhold KJ
Clin Cancer Res, 2017
tumorflownull result
null
LowModerate
small-npbmc-only-generalizedno-multiplicity-correction
PMID PMCID DOI critique28951518window-of-opportunityPer trialFOXP3+frequency-of-lymphocytesearly-on-treatmentSurgical resection post-neoadjNot measured — no pretreatment tumor samples availableHigher and more variable Treg levels than PBMCs in 7 post-resection tumors; no pre/post comparisonCannot assess change — authors state 'in the absence of pre-treatment tumor samples, we are unable to adequately assess the effect of therapy on Treg frequencies within the tumor microenvironment'not tested (paired analysis impossible)exploratory-but-prespecifiedpmc_full_textYi 2017 tumor compartment. Full-text backfill 2026-04-23: authors explicitly disclaim ability to assess Treg change in tumor (no pre-treatment biopsy). This row is 'not-assessed' correctly — retained as a documented limitation and because post-treatment tumor Treg data is still in-scope per schema.
Denileukin diftitoxMycosis fungoides / Sézary syndrome (CTCL)15
Geskin LJ ··· Falo LD
Cancer Immunol Immunother, 2018
PBMCflow↓ −29%significant reduction
depletion
ModerateModerate
cd25-gating-confoundsmall-nno-multiplicity-correction
PMID PMCID DOI critique29204699single-arm-descriptiveStandardCD4+CD25highFoxP3+frequency-of-CD4early-on-treatmentduring treatment cyclesNot tabulated; CD4+FoxP3+ baseline count in blood per patient (n=15)Median relative intra-patient change −29% in CD4+FoxP3+ (94% CI −83% to −20%) after one DD cycleMedian 29% reduction after one cycle (94% CI −83% to −20%); responders had significant 20-45% absolute number decrease after cycle 1; consecutive cycles produced sustained depletionp=0.03Transient single-cycle effect with rebound between cycles; sustained with consecutive cyclesmechanism-targetedpmc_full_textGeskin 2018 — CTCL DD study. Full-text backfill 2026-04-23: median 29% reduction (94% CI −83%–−20%), p=0.03; responders achieved 20-45% decrease after cycle 1. Skin Treg decrease qualitatively shown in representative patient (unquantified).
PanobinostatHIV-1 infection on suppressive cART (reservoir reactivation study)15
Brinkmann CR ··· Tolstrup M
mSphere, 2018
PBMCflow↑ +40%increase
null
ModerateLow
small-nno-multiplicity-correction
PMID PMCID DOI NCT critique29468194paired-pre-post20 mg PO 3× weekly x 8 weeksCD4+CD25+FOXP3+frequency-of-CD4early-on-treatmentday 4 (peak) and day 28 (on-treatment)baseline Treg proportion (value not numerically reported in abstract)+40% at day 4; sustained elevation at day 28+40% Treg proportion at day 4 (p=0.003); similar elevation at day 28 (p=0.004)p=0.003 (day 4); p=0.004 (day 28)Treg elevation returned to baseline by 24-week follow-up post-treatmentpre-specified-endpointpmc_full_textBrinkmann 2018 mSphere. PMC full text (PMC5812898). HIV reservoir-reactivation study — the pre-specified hypothesis was not Treg-depletion per se, but Treg PD was pre-specified. Panobinostat INCREASED Treg frequency and activation markers, opposite to the HDACi-driven Treg depletion paradigm in oncology. Important cross-indication counter-example: HDACi effects are context-dependent. Transient — returned to baseline 24 weeks post-treatment.
Ipilimumab or tremelimumabMelanoma, prostate, bladder45
Sharma A ··· Sharma P
Clin Cancer Res, 2019
tumorflow↑ sig.increase
null
HighModerate
foxp3-ihc-single-markersmall-nbaseline-imbalance
PMID PMCID DOI critique30054281paired-pre-postPer trialFOXP3+frequency-of-lymphocytesearly-on-treatmentPaired pre/postNumeric density values shown only in Fig 2A plots without text quantificationNumeric density values shown only in Fig 2A plots without text quantification; direction is INCREASE across melanoma (ipi n=16 post vs 19 untreated; treme n=18 paired), no reduction in bladder (n=9) or prostate (n=16)Both ipi (Mann-Whitney unpaired) and treme (Wilcoxon paired) significantly INCREASED FOXP3+ density in melanoma, p<0.05; 2 pre-treme patients with zero baseline FOXP3+ gained FOXP3+ infiltrate post-treme; bladder and prostate: no reductionp<0.05 for melanoma cohorts (both ipi and treme); exact p-values not stated in text (figure-only)mechanism-targetedpmc_full_textSharma 2019 — foundational human null result. Full-text backfill 2026-04-23: both anti-CTLA-4 agents increased rather than depleted intratumoral FOXP3+ cells across melanoma, bladder, and prostate; exact density numbers in Fig 2A plots not textually quantified in paper. Consistent with Huang 2011 (21558401) baseline 35→167 cells/mm^2; both support the absence of Fc-mediated Treg depletion by non-Fc-enhanced anti-CTLA-4 in humans. Conflict pair with Ager 2026 (41759531): Ager shows Fc-enhanced anti-CTLA-4 DOES deplete intratumoral Tregs — the Fc engineering is the reconciling difference.
Bempegaldesleukin (NKTR-214)Advanced/metastatic solid tumors28
Bentebibel SE ··· Diab A
Cancer Discov, 2019
PBMCflow↑ qual.ratio-shift only
fraction shift
LowModerate
abstract-onlyspin-abstract-vs-resultsindustry-sponsored
PMID DOI NCT critique30988166single-arm-descriptiveDose-escalationCD4+CD25+FoxP3+ratio-to-CD8early-on-treatmentPost-dose serialCD8/Treg ratio increased; absolute Treg expansion but skewed toward effectorsreportedpre-specified-endpointpubmed_abstractBentebibel 2019 — bempeg first-in-human. Full-text backfill 2026-04-23: not in Europe PMC OA (inEPMC=N, subscription required). Abstract retains 'promoted immune cell increase with limited increase of Tregs' — consistent with the ratio-shift path. No numeric baseline/post Treg, CD8:Treg ratio, or fold change extractable from abstract.
Bempegaldesleukin (NKTR-214) + nivolumabNKTR-214 + nivolumabAdvanced solid tumors (melanoma, RCC, NSCLC, UC)38
Diab A ··· Cho DC
Cancer Discov, 2020
PBMCflow↑ qual.ratio-shift only
fraction shift
LowSerious
abstract-onlyspin-abstract-vs-resultsindustry-sponsored
PMID DOI NCT critique32439653single-arm-descriptiveDose-escalationCD4+CD25+FoxP3+ratio-to-CD8early-on-treatmentPost-dose serialCD8/Treg ratio shift; Treg absolute expansionreportedpre-specified-endpointpubmed_abstractDiab 2020 PIVOT-02 — bempeg+nivo. Full-text backfill 2026-04-23: not in Europe PMC OA (inEPMC=N, subscription required). Abstract: 'increased infiltration, activation, and cytotoxicity of CD8+ T cells, without regulatory T-cell enhancement' — supports ratio-shift framing but no numeric values extractable.
Vorinostat + tamoxifen + pembrolizumabvorinostat (HDACi) + tamoxifen (endocrine) + pembrolizumabER+ advanced breast cancer, hormone-refractory21
Terranova-Barberio M ··· Munster PN
Nat Commun, 2020
tumorflow↓ −75.4%significant reduction
depletion
ModerateSome concerns
small-nresponder-subset-reportingindustry-sponsored
PMID PMCID DOI NCT critique32681091paired-pre-postvorinostat + tamoxifen run-in, then add pembrolizumabCD4+FoxP3+CTLA-4+ (activated Treg)frequency-of-CD4early-on-treatmentpost-run-in (pre-pembrolizumab)11.8% CD4+FoxP3+CTLA-4+ overall; 20.3% responders; 10.4% non-responders2.9% overall; 4.2% responders; 2.5% non-respondersoverall 11.8% → 2.9% (−75%); responders 20.3% → 4.2% (−79%); non-responders 10.4% → 2.5% (−76%)p=0.0067 overall; p=0.031 responders; p=0.034 non-respondersmeasured at end of run-in (~4 weeks)mechanism-targetedpmc_full_textTerranova-Barberio 2020 Nat Commun. PMC full text (PMC7367885). Vorinostat HDACi-driven intratumoral Treg depletion replicated across responders and non-responders — notable because Treg depletion alone was not sufficient to predict benefit in this cohort. PBMC Tregs were not reported as depleted (tumor-specific effect).
Denileukin diftitox + IFNαIFNαAdvanced ovarian cancer12
Thibodeaux SR ··· Curiel TJ
Clin Cancer Res, 2021
PBMCflow↓ sig.significant reduction
depletion
LowSerious
cd25-gating-confoundabstract-onlycase-report-n-of-fewspin-abstract-vs-results
PMID DOI critique33771857single-arm-descriptivePer protocolCD4+CD25highFoxP3+frequency-of-CD4early-on-treatmentduring combination cyclesaugmented depletion with IFNαreported significantmechanism-targetedpubmed_abstractThibodeaux 2021 — DD+IFNα in ovarian cancer. Full-text backfill 2026-04-23: Clin Cancer Res article not in Europe PMC OA (inEPMC=N, subscription required). Abstract retains qualitative finding that DD depleted Tregs and IFNα augmented antitumor immunity; no numeric baseline/post Treg values extractable.
Low-dose decitabineImmune thrombocytopenia (ITP)32
Han P ··· Hou M
Blood, 2021
PBMCflow↑ sig.increase
null
ModerateModerate
no-multiplicity-correction
PMID PMCID DOI critique33876188paired-pre-post3.5 mg/m² IV x 3 days per 4-week cycle; 3 cycles totalCD4+CD25+FOXP3+frequency-of-CD4lateday 85 (post-3-cycle completion, ~12 weeks)pretreatment Treg frequency (not numerically reported)significantly increased Treg quantity and suppressive functionTreg quantity and function 'substantially improved' (p<0.05); no numeric % reportedp<0.05measured at day 85 post-initiation; durable through treatment windowpre-specified-endpointpmc_full_textHan 2021 Blood (PMC8394906). Companion suppressive-function assay is paired with the count data — Tregs increased in BOTH quantity AND function (ex vivo CFSE-based suppression assay). This is opposite to Treg-depletion phenotype — an important null/counter-example for DNMTi effect on Tregs. Low-dose decitabine in autoimmunity tilts the balance TOWARD Treg dominance.
Entinostat + nivolumab ± ipilimumabentinostat (HDACi) + nivolumab ± ipilimumabAdvanced solid tumors (multiple histologies)14
Roussos Torres ET ··· Connolly RM
Clin Cancer Res, 2021
tumorflow↑ +119.7%nonsignificant trend
ratio only
ModerateModerate
compartment-dissociationsmall-nno-multiplicity-correctionindustry-sponsored
PMID PMCID DOI NCT critique34135021paired-pre-postentinostat 5 mg PO weekly (2-week run-in, then with ICI)FOXP3+ cells (tumor IHC); CD8/FoxP3 ratioratio-to-CD8midPost-8-week combination (T2) vs baseline (T0)median CD8/FoxP3 ratio 4.11 (baseline)median CD8/FoxP3 ratio 9.03 at T2 (post-combination)CD8:FoxP3 ratio increased 4.11 → 9.03 (2.2× shift in favor of CD8)p=0.002 (Wilcoxon signed-rank, T0 vs T2)measured at 8 weeks combination therapypre-specified-endpointpmc_full_textRoussos Torres 2021 CCR (ETCTN-9844). PMC full text (PMC8563383). The ratio-shift is driven by both CD8 expansion and FoxP3 decrease; absolute Treg change not separately quantified. Entinostat monotherapy was insufficient — ICI was required for the shift. Note pct_change is for the CD8/FoxP3 ratio, not Tregs directly.
GWN323 (anti-GITR) ± spartalizumab (anti-PD-1)SpartalizumabAdvanced solid tumors and lymphomas53
Piha-Paul SA ··· Bedard PL
J Immunother Cancer, 2021
PBMCflow↓ qual.nonsignificant trend
depletion
LowModerate
dose-mixed-analysisexploratory-endpointsingle-arm-no-controlindustry-sponsored
PMID PMCID DOI NCT critique34389618single-arm-descriptiveDose-escalationCD4+FoxP3+frequency-of-CD4early-on-treatmentOn-treatmentMost patients had <1% FoxP3 at screening; 4 patients had >1% FoxP3 at baseline3 of 4 high-baseline patients had on-treatment FoxP3 decrease; non-dose-dependentInconsistent decreases limited to the 4/53 patients with detectable baseline Tregs; 3/4 of those decreased; non-dose-dependent across 10-1500 mg rangenot tested; insufficient Npre-specified-endpointpmc_full_textPiha-Paul 2021 JITC GWN323 phase I. Full-text backfill 2026-04-23: authors explicitly note 'because most patients have no Foxp3 Treg cells in the tumor microenvironment at baseline, it may be impossible to test the hypothesis that GWN323 decreases Treg cells'; only 4 patients had assessable baseline Tregs; 3/4 decreased; non-dose-dependent. Classic anti-GITR human mixed result; underpowered for depletion claim.
MogamulizumabSézary syndrome (CTCL)26
Roelens M ··· Moins-Teisserenc H
Br J Dermatol, 2022
PBMCflow↓ sig.significant reduction
depletion
ModerateModerate
abstract-onlyindustry-sponsored
PMID DOI critique35041763paired-pre-postStandardCD4+CD25+FOXP3+ activated Tregsfrequency-of-CD4early-on-treatmentWithin first 4 weeksdrastic decrease in activated Tregs within first 4 weeksreported significantLong-term immune restoration notedmechanism-targetedpubmed_abstractRoelens 2022 — long-term moga PD in Sézary syndrome. Full-text backfill 2026-04-23: Br J Dermatol article not in Europe PMC OA (inEPMC=N, subscription required). Abstract retains qualitative 'drastic decrease in activated Tregs within first 4 weeks'; 17/26 patients with early complete blood response correlated with higher baseline CCR4 expression. No numeric baseline/post values extractable.
MogamulizumabSézary syndrome (CTCL)26
Roelens M ··· Moins-Teisserenc H
Br J Dermatol, 2022
skinflowmixedsignificant reduction
depletion
ModerateModerate
abstract-onlyindustry-sponsored
PMID DOI critique35041763paired-pre-postStandardCD4+CD25+FOXP3+frequency-of-CD4lateLong-term follow-upLong-term immune restoration; tumor heterogeneity reshapedreportedLong-term restoration observedmechanism-targetedpubmed_abstractRoelens 2022 skin compartment. Full-text backfill 2026-04-23: article not OA; abstract only describes 'long-term immune restoration' qualitatively for the skin compartment. No numeric skin Treg data extractable.
IdelalisibRelapsed/refractory chronic lymphocytic leukemia9
Gadi D ··· Brown JR
Br J Haematol, 2022
PBMCflow↓ sig.significant reduction
depletion
LowModerate
very-small-nno-multiplicity-correction
PMID PMCID DOI NCT critique35170759paired-pre-post150 mg PO BID (per-label)CD4+CD25+FOXP3+frequency-of-CD4early-on-treatmentvisits 6-12 (roughly month 1-3 on treatment)pre-treatment Treg frequency (not numerically reported)uniformly decreased across all 9 patientsuniform decrease in Tregs with PI3Kδ inhibition (no numeric % in paper)uniform across cohort; CD8:Treg ratio increase only statistically significant in toxicity subgroup (p<0.05)mechanism-targetedpmc_full_textGadi 2022 Br J Haematol. PMC full text (PMC9263710). Second trial is NCT01539291 (GS-US-312-0117). Small translational cohort (N=9) from the idelalisib phase III registration. Uniform Treg decrease reported qualitatively; no absolute numerics in full text. Toxicity-driving mechanism appears to be Th17 activation on top of Treg loss, not Treg loss alone.
Iberdomide (CC-220, cereblon modulator / Ikaros-Aiolos degrader)Active systemic lupus erythematosus81
Lipsky PE ··· Schafer PH
Ann Rheum Dis, 2022
PBMCflow↑ +104.9%increase
null
ModerateSome concerns
no-multiplicity-correctionexploratory-endpointindustry-sponsoredauthor-coi-sponsor
PMID PMCID DOI NCT critique35477518randomized-controlled0.45 mg PO dailyTSDR demethylation (epigenetic Treg definition)frequency-of-CD4lateweek 24 vs placebobaseline Treg frequency (not reported numerically in abstract/paper)+104.9% vs placebo at 0.45 mg+104.9% increase in Tregs at 0.45 mg vs placebo at week 24p<0.001 vs placebomeasured at week 24 on continued dosingpre-specified-endpointpmc_full_textLipsky 2022 Ann Rheum Dis (PMC9279852). CELMoD iberdomide degrades Ikaros (IKZF1) and Aiolos (IKZF3) — NOT Helios (IKZF2). The consequence in SLE is IL-2-driven Treg EXPANSION, not destabilization. Critical conceptual boundary: Ikaros/Aiolos-degrading CELMoDs do not destabilize Tregs; an IKZF2-selective degrader would be required. This row anchors that distinction and corrects an initial assumption in the scope expansion.
TRX518 (anti-GITR) single agent or combo (gemcitabine / pembrolizumab / nivolumab)Gemcitabine OR pembrolizumab OR nivolumabAdvanced solid tumors109
Davar D ··· Luke JJ
Clin Cancer Res, 2022
PBMCflowmixednonsignificant trend
depletion
LowModerate
dose-mixed-analysissingle-arm-no-controlno-multiplicity-correctionindustry-sponsored
PMID PMCID DOI NCT critique35499569single-arm-descriptiveDose-escalationCD4+FoxP3+frequency-of-CD4early-on-treatmentSerial; combo-regimen-dependent kineticsBaseline GITR+ Treg frequency: mean 41.82%, range 9.11-100% (Part C gem+TRX518 cohort); mean 36.63%, range 12.25-54.95% (Parts D+E anti-PD-1 combo cohort)Monotherapy (Parts A+B, n=43): SD patients (n=11) had 'more substantial decreases in peripheral Tregs and eTregs' than PD patients; GITR+ Tregs consistently reduced in all patients, greater reduction in PD; gem combo: gem reduced Tregs days 1/8, TRX518 expanded on day 2 (cycle-level oscillation); anti-PD-1 combo: less consistent, CR patient had Treg INCREASEModest, inconsistent peripheral Treg reductions; kinetics varied by combo regimen; numeric fold-changes not text-quantified (figure-only)p<0.05 indicated by asterisks in Fig 3A (unpaired t-test); exact values not statedCombo-regimen-dependent: gem oscillation d1/8 (down) vs d2 (up with TRX518); anti-PD-1 less consistentpre-specified-endpointpmc_full_textDavar 2022 TRX518 Phase Ib. Full-text backfill 2026-04-23: modest inconsistent peripheral Treg reductions with significant combo-regimen dependence; baseline GITR+ frequency means provided (41.82% gem cohort, 36.63% anti-PD-1 cohort); ORR 3.2-12.5% across parts. Quantitative values mostly in figures without text numbers.
TRX518 (anti-GITR) single agent or comboGemcitabine OR pembrolizumab OR nivolumabAdvanced solid tumors20
Davar D ··· Luke JJ
Clin Cancer Res, 2022
tumorflowmixednonsignificant trend
depletion
LowModerate
dose-mixed-analysissingle-arm-no-controlno-multiplicity-correctionindustry-sponsored
PMID PMCID DOI NCT critique35499569paired-pre-postDose-escalationFoxP3+frequency-of-lymphocytesearly-on-treatmentPre and on-treatment biopsyPer-tumor baseline; Fig 4A shows trajectories without tabulated densityMonotherapy (Parts A+B, n=13 evaluable): 7/13 had decreased intratumoral Tregs at C1D21; anti-PD-1 combo (Parts D+E, n=9 paired): 3 responders had 'profound intratumoral Treg reductions', 6 non-responders had increased or stable tumor Tregs; gem combo (Part C, n=21): no consistent change, clinical-benefit patients had INCREASED GITR+ Treg infiltrationMonotherapy: 7/13 (54%) decreased tumor Tregs; anti-PD-1 combo: 3/3 responders deep-depleters vs 6/6 non-responders not; gem combo: paradoxical increase in clinical benefitersPaired t-test performed on Fig 4B; exact p not stated in textC1D21 biopsy timepointpre-specified-endpointpmc_full_textDavar 2022 TRX518 tumor. Full-text backfill 2026-04-23: 7/13 monotherapy patients depleted; 3/3 anti-PD-1 responders vs 0/6 non-responders (striking correlation); gem combo paradoxically enriched GITR+ Tregs in responders.
Decitabine + ipilimumabdecitabine (DNMTi) + ipilimumab (anti-CTLA-4)Relapsed/refractory AML/MDS (post-allo-HCT and transplant-naïve)36
Penter L ··· Wu CJ
Blood, 2023
bone-marrowflow↑ sig.increase
null
ModerateModerate
small-nno-multiplicity-correctionindustry-sponsored
PMID PMCID DOI NCT critique36706355paired-pre-postdecitabine 20 mg/m² IV d1-5 lead-in; ipilimumab 3 or 10 mg/kg q3wCD3+FOXP3+ (scRNA + multiplex IF)frequency-of-CD3early-on-treatmentpost-decitabine lead-in + post-ipilimumab infusion(s)baseline marrow Treg density (not numerically reported)increased CD3+FOXP3+ density post-ipilimumabipilimumab increased marrow-infiltrating Treg frequency (validated by scRNA-seq + mIF)reported as qualitatively significant (no p-value cited in text)mechanism-targetedpmc_full_textPenter 2023 Blood (PMC10122106) / Garcia 2023 Blood companion paper (PMID 36332187). This finding CONFLICTS with the canonical view that anti-CTLA-4 depletes tumor Tregs via ADCC. In the AML/MDS bone-marrow niche, ipilimumab (non-Fc-enhanced) appears to expand rather than deplete Tregs. Supports the Ager 2026 / Sharma 2019 Fc-engineering-reconciling-variable framework surfaced in the prior backfill run. Reinforces the rationale for Fc-enhanced anti-CTLA-4 (botensilimab, etc.) in Treg-rich niches.
Mogamulizumab (KW-0761) — anti-CCR4 Treg-targetedCCR4-negative advanced solid tumors49
Fujikawa K ··· Wada H
PLoS One, 2023
PBMCflow↓ −90%significant reduction
depletion
HighModerate
industry-sponsoredauthor-coi-sponsor
PMID PMCID DOI critique37729184paired-pre-postPer 1a/1b dose-escalationCCR4+FOXP3+ eTregfrequency-of-CD4early-on-treatment2 weeks post-first dose; sustained during treatmentMedian 2.1% eTreg of CD4+ T cells (range 0.45-6.1%)Median 0.20% eTreg of CD4+ (range 0.04-0.92%) at 4 weeks post-first doseMedian ~90% reduction (from 2.1% to 0.20%); eTreg depletion in all but 2 patients (where samples unavailable), 37 evaluable of 49reported in all patients (p-value not stated)Sustained eTreg depletion during treatment, particularly durable in patients with clinical responsemechanism-targetedpmc_full_textFujikawa 2023 PLoS One — integrated phase 1a/1b mogamulizumab. Full-text backfill 2026-04-23: median 2.1% → 0.20% at 4 weeks (~90% reduction); dose-independent (0.1-1.0 mg/kg).
Tiragolumab + atezolizumabatezolizumab (anti-PD-L1)PD-L1-positive NSCLC16
Guan X ··· Patil NS
Nature, 2024
PBMCflow↓ qual.nonsignificant trend
depletion
LowModerate
small-nexploratory-endpointindustry-sponsoredauthor-coi-sponsor
PMID PMCID DOI NCT critique38418879paired-pre-posttiragolumab 600 mg q3w + atezolizumab 1200 mg q3wFOXP3+ fraction of CD4+ T cellsfrequency-of-CD4early-on-treatmenton-treatment (cycle not specified in text)circulating Treg fraction of CD4+ (value not numerically reported)decreased fraction of total CD4+ T cellsTreg fraction of total CD4 decreased on treatment (magnitude not quantified in manuscript)reported as a group-level change; p-value not givenexploratory-but-prespecifiedpmc_full_textGuan 2024 Nature (CITYSCAPE NCT03563716 + phase 1b GO30103 translational cohort). PMC full text (PMC11139643). Peripheral Treg frequency decreased on-treatment but tumor Treg depletion not directly demonstrated in clinical samples — mouse CT26 data supported FcγR-dependent gene-signature shift only. Cleanest anti-TIGIT clinical Treg PD data available as of 2026-04-23; lacking numeric values.
Iberdomide + dexamethasonedexamethasoneRelapsed/refractory multiple myeloma197
Amatangelo M ··· Thakurta A
Cell Rep Med, 2024
bone-marrowflownull result
null
ModerateModerate
exploratory-endpointno-multiplicity-correctionindustry-sponsoredauthor-coi-sponsor
PMID PMCID DOI NCT critique38776914single-arm-descriptiveiberdomide 0.3-1.6 mg PO + dex (CC-220-MM-001)CD4+ regulatory phenotype (flow)frequency-of-CD4baselinescreening bone marrow aspirate6.9% of CD4+ T cells Treg phenotype (all-comer median)non-responders significantly higher baseline Treg vs responders (p<0.001)baseline-only biomarker (no longitudinal depletion reported)non-responder vs responder Treg: p<0.001 (baseline biomarker)exploratory-but-prespecifiedpmc_full_textAmatangelo 2024 Cell Rep Med (PMC11228401). CC-220-MM-001 translational analysis. This row captures the BASELINE Treg biomarker finding, not a longitudinal depletion. Iberdomide in MM does NOT demonstrably deplete Tregs; baseline Treg elevation is a resistance marker. Confirms Lipsky 2022 SLE finding that iberdomide's mechanism is not Treg-depletion.
Bempegaldesleukin + nivolumabNKTR-214 + nivolumabMelanoma / RCC / UC40
Gogas H ··· Lebbé C
NPJ Precis Oncol, 2024
PBMCflow↑ +800%ratio-shift only
fraction shift
ModerateModerate
no-multiplicity-correctionindustry-sponsored
PMID PMCID DOI NCT critique39025948paired-pre-postPer trialCD4+FOXP3+ratio-to-CD8early-on-treatmentSerial on-treatmentC1D1 baseline Treg frequency; per-patient data shown in Fig 4~8-10x increase in absolute CD4+CD25+FoxP3+ Treg counts at C1D8 and C5D8 (bempeg+nivo arm); CD8+ T cells ~2x increase at same timepointsBempeg+nivo arm: Treg ~8-10x ABSOLUTE expansion but CD8/Treg ratio DECREASED at C1D8/C5D1/C5D8 vs baseline (Treg expansion outpaced CD8 2x expansion); nivo-monotherapy arm: ratios stablep<0.00001 / p<0.0001 (multiple comparisons via asterisks in Fig 4; exact p not stated)Serial sampling C1D1/C1D8/C5D1/C5D8pre-specified-endpointpmc_full_textGogas 2024 — PIVOT-02 biomarker re-analysis. Full-text backfill 2026-04-23: 8-10x Treg absolute expansion with bempeg+nivo (ratio shift NEGATIVE — Treg outpaced CD8); this actually argues AGAINST bempeg achieving a favorable Treg-relative effect. Row retained per user's explicit ratio-shift-path inclusion spec but directionality is unfavorable.
Botensilimab (AGEN1181) + balstilimab (anti-PD-1)BalstilimabAdvanced solid tumors (poorly ICI-responsive)12
Chand D ··· Stein RB
Cancer Discov, 2024
tumorflow↓ sig.significant reduction
depletion
ModerateModerate
small-nsingle-arm-no-controlindustry-sponsoredauthor-coi-sponsor
PMID PMCID DOI NCT critique39083809paired-pre-postPer dose-escalationFOXP3+frequency-of-lymphocytesearly-on-treatmentOn-treatment biopsyNot quantified in main text; RNA-seq-based signal (Fig 5H)Significant intratumoral Treg reduction by IHC and RNA-seq signature (Fig 5H); fold-change and p-value not stated in textHuman: significant intratumoral FOXP3+ reduction (IHC); numeric values not text-quantified. Mouse CT26: 'significant intratumoral FOXP3+ Treg reduction up to 10 days posttreatment' and increased CD8/Treg ratio (Fig 1D). Human PBMC mechanism: not attributed to depletion but to reduced TGFβ1 secretion (Suppl Fig S9B).reported significant (intratumoral IHC); exact p not statedMouse: sustained up to 10 days post-treatment; human: single on-treatment biopsymechanism-targetedpmc_full_textChand 2024 Cancer Discov — botensilimab translational. Full-text backfill 2026-04-23 (via Europe PMC PMCID PMC11609826): intratumoral FOXP3+ decrease in human IHC+RNA-seq but numerics not text-quantified; PBMC/serum Tregs unchanged (tumor-selective); preclinical mouse data more quantitative. Updated with PMCID.
Intraperitoneal denileukin diftitox (ONTAK)Recurrent refractory ovarian cancer10
Liao JB ··· Salazar LG
Gynecol Oncol, 2024
PBMCflow↓ −73%significant reduction
depletion
ModerateModerate
very-small-ndose-mixed-analysisno-multiplicity-correctionauthor-coi-sponsor
PMID PMCID DOI critique39362046single-arm-descriptiveDose-escalation; MTD 15 µg/kgCD4+CD25highFoxP3+frequency-of-CD4early-on-treatmentserial during dose escalationMean FoxP3 0.1726 ± 0.0442 (n=6) at baseline (pooled dose levels)Mean FoxP3 0.0374 ± 0.0101 (n=5) at week 8Mean 73% reduction pooled; by dose: 5 µg/kg cohort 58.9% reduction (p=0.1500); 15 µg/kg cohort 83.2% reduction (p=0.0374); 5/9 patients achieved ≥25% reduction (secondary efficacy threshold)p=0.0275 (pooled); p=0.0374 (15 µg/kg)8-week on-treatment measurement; recovery not reportedmechanism-targetedpmc_full_textLiao 2024 — IP route in ovarian. Full-text backfill 2026-04-23: pooled p=0.0275 with 73% reduction; dose-level breakdown shows only 15 µg/kg significant (p=0.0374).
Intraperitoneal denileukin diftitox (ONTAK)Recurrent refractory ovarian cancer10
Liao JB ··· Salazar LG
Gynecol Oncol, 2024
ascitesflow↓ −67%nonsignificant trend
depletion
ModerateModerate
very-small-ndose-mixed-analysisno-multiplicity-correctionauthor-coi-sponsor
PMID PMCID DOI critique39362046single-arm-descriptiveDose-escalation; MTD 15 µg/kgCD4+CD25highFoxP3+frequency-of-CD4early-on-treatmentserialMean FoxP3 0.1855 ± 0.0945 (n=3) at baselineMean FoxP3 0.0597 ± 0.0304 (n=3) at week 8Mean 67% reduction in ascites FoxP3; 3 patients achieved ≥25% reduction (immunologic efficacy threshold)p=0.2737 (n.s.; small sample)8-week on-treatment measurementmechanism-targetedpmc_full_textLiao 2024 ascites compartment. Full-text backfill 2026-04-23: 67% mean reduction, n.s. (p=0.2737) — reclassified as 'partial' because direction is consistent with PBMC but underpowered (n=3 paired).
Nemvaleukin alfa (ALKS 4230) monotherapyAdvanced solid tumors (ARTISTRY-1)46
Vaishampayan UN ··· Velcheti V
J Immunother Cancer, 2024
PBMCflow↑ +100%increase
ratio only
ModerateModerate
single-arm-no-controlno-multiplicity-correctionindustry-sponsored
PMID PMCID DOI NCT critique39567211single-arm-descriptive6 µg/kg/day IV days 1-5 q21dCD4+CD25+FoxP3+frequency-of-CD4early-on-treatmentSerial cyclesC1D1 baseline; per-patient data onlyMax fold change from baseline (FCBmax) for Tregs ~2x in both melanoma and RCC cohorts; CD8+ 2.53x, NK 6.52x for comparison (Part B monotherapy)Tregs expanded ~2x (modest); CD8+ 2.53x; NK 6.52x — ratios favor effector expansion. Treg expansion limited to C1D5 onlyreported qualitatively; no per-comparison p-values in main textTransient Treg expansion at C1D5 only; effector expansion at D8 (cycle 1) and D22 (cycle 2)pre-specified-endpointpmc_full_textVaishampayan 2024 ARTISTRY-1 monotherapy. Full-text backfill 2026-04-23: Treg FCBmax ~2x vs NK 6.52x / CD8 2.53x; nemva's IL-2R-βγ bias limited Treg expansion as designed. Kept via ratio-shift path.
Nemvaleukin alfa + pembrolizumabPembrolizumabAdvanced solid tumors (ARTISTRY-1 Part C)166
Vaishampayan UN ··· Velcheti V
J Immunother Cancer, 2024
PBMCflow↑ qual.increase
ratio only
ModerateModerate
single-arm-no-controlno-multiplicity-correctionindustry-sponsored
PMID PMCID DOI NCT critique39567211single-arm-descriptive6 µg/kg/day IV days 1-5 q21dCD4+CD25+FoxP3+frequency-of-CD4early-on-treatmentSerial cyclesC1D1 baseline; per-patient data onlySimilar minimal Treg expansion pattern as monotherapy (~2x FCBmax)Nemva+pembro: minimal Treg expansion; effector expansion preservedreported qualitativelypre-specified-endpointpmc_full_textARTISTRY-1 Part C combo. Full-text backfill 2026-04-23: combo cohort showed the same minimal Treg expansion pattern as monotherapy; CD8/NK ratios remained favorable. No separate numeric table for combo vs mono.
Denileukin diftitox (E7777 / I/ONTAK)Treatment-refractory stage IV breast cancer15
Gwin WR ··· Disis ML
Vaccines (Basel), 2025
PBMCflow↓ qual.nonsignificant trend
depletion
LowModerate
cd25-gating-confoundsmall-nindustry-sponsored
PMID PMCID DOI critique40006664single-arm-descriptivePer protocol, up to six 21-day cyclesCD4+CD25+FOXP3+frequency-of-CD4early-on-treatmentpost-cyclePer-patient baseline; aggregate not tabulatedNo significant difference between baseline and maximal observed Treg levels (overall p=0.10)Overall depletion n.s. (p=0.10); 6/15 patients (40%) achieved ≥25% Treg reduction with mean reduction 56.0% ± 10.96% (SD) in this responder subsetp=0.10 (overall, n.s.)Most reductions occurred after cycle 2; limited by rapid anti-DT IgG response (100% of 9 evaluable patients at week 6, p<0.005)mechanism-targetedpmc_full_textGwin 2025 — partial depletion in breast cancer. Full-text backfill 2026-04-23: overall p=0.10 (n.s.); responder subset (6/15, 40%) had 56.0% ± 10.96% mean reduction; 100% anti-DT IgG response by week 6 likely limited efficacy.
Mogamulizumab + nivolumab neoadjuvantNivolumab (3 doses) + mogamulizumab (4 doses)Operable solid tumors (renal, lung, esophageal, oral SCC)16
Jinushi K ··· Wada H
J Immunother Cancer, 2025
tumorflow↓ −86.7%significant reduction
depletion
ModerateLow
small-nsingle-arm-no-controlindustry-sponsored
PMID PMCID DOI critique40180420window-of-opportunityPer protocol neoadjuvantCCR4+FOXP3+ Tregsfrequency-of-CD4early-on-treatmentPreoperative post-neoadjuvant windowPer-tumor baseline CCR4+FoxP3+ density, not aggregatedMedian −86.7% change in CCR4+FoxP3+ (range −94.8% to −52.7%) in all 16 patients; total FoxP3+ median change −11.1% (range −73.2% to +87.8%), decreased in 50% of patientsCCR4+ eTreg: median 86.7% reduction, depleted in 16/16; total FoxP3+ mixed response, 8/16 decreasedreported; p-values not publishedMeasured at surgery (preoperative neoadjuvant window)mechanism-targetedpmc_full_textJinushi 2025 JITC — neoadjuvant moga+nivo. Full-text backfill 2026-04-23: median 86.7% reduction in CCR4+FoxP3+ eTregs (100% depleted); total FoxP3+ more variable (median −11.1%, 50% decreased).
Mogamulizumab + recombinant human IL-15 (rhIL-15)Mogamulizumab + rhIL-15R/R T-cell malignancies (ATLL, MF/SS)6
Gordon MJ ··· Roschewski M
Blood Neoplasia, 2025
PBMCflowratio-shift only
depletion
LowModerate
very-small-nsurface-marker-gatingindustry-sponsored
PMID PMCID DOI critique40546724single-arm-descriptiveDose-escalationCD4+FOXP3+ (presumed)frequency-of-CD4early-on-treatmentFirst cycleNK expansion and tumor cell reduction reported; Treg-specific numeric not in abstractnot testedmechanism-targetedpmc_full_textGordon 2025 — mogamulizumab + rhIL-15 phase 1 in R/R T-cell malignancies. Full-text backfill 2026-04-23: PMC article reviewed (PMC12182836). Paper focuses on NK cell expansion and ADCC; no quantitative Treg baseline/post values, p-values, or fractional changes reported. Mechanism of mogamulizumab Treg depletion is assumed by reference to prior moga literature but NOT measured in this trial. Row retained because moga is mechanism-targeted and this is a mogamulizumab-containing regimen, but Treg PD is NOT a pre-specified endpoint here — borderline case.
Nemvaleukin alfa monotherapyAdvanced melanoma and RCC (post-ICI)74
Calvo E ··· McDermott DF
J Immunother Cancer, 2025
PBMCflow↑ +100%increase
ratio only
ModerateModerate
single-arm-no-controlno-multiplicity-correctionindustry-sponsored
PMID PMCID DOI NCT critique40759440single-arm-descriptive6 µg/kg/day IV days 1-5 q21dCD4+CD25+FoxP3+frequency-of-CD4early-on-treatmentSerial on-treatmentC1D1 baseline; per-patient onlyTreg fold change ~2x (FCBmax at C1D5); CD8+/NK expansion larger at C1D8/C2D22Tregs ~2x FCBmax; effector cells (CD8+/NK) FCB larger at D8/D22; post-ICI melanoma and RCC both show this patternreported qualitativelypre-specified-endpointpmc_full_textCalvo 2025 ARTISTRY-1 Part B post-ICI cohort. Full-text backfill 2026-04-23: consistent ~2x Treg FCBmax limited to C1D5, contrasting with sustained effector expansion at D8/D22.
Nemvaleukin alfa (less-frequent IV dosing)Advanced solid tumors30
Piha-Paul SA ··· Lakhani NJ
Oncologist, 2025
PBMCflow↑ qual.increase
ratio only
LowModerate
single-arm-no-controlno-multiplicity-correctionindustry-sponsored
PMID PMCID DOI critique40990800single-arm-descriptiveQ-variable IV schedulesCD4+CD25+FoxP3+frequency-of-CD4early-on-treatmentSerial across schedulesC1D1 baseline; per-patient onlyLow-level transient non-dose-dependent Treg expansion; favorable effector:Treg ratios maintainedMinimal Treg expansion across schedules; figures onlyreported qualitativelypre-specified-endpointpmc_full_textPiha-Paul 2025 ARTISTRY-3 less-frequent dosing. Full-text backfill 2026-04-23: 'low-level, transient, non-dose-dependent expansion of Tregs' with favorable NK:Treg and CD8:Treg ratios; Treg quantitative data in Fig 6 only.
BMS-986218 (Fc-enhanced anti-CTLA-4) + androgen deprivation therapy (ADT) neoadjuvantAndrogen deprivation therapy (ADT)High-risk localized prostate cancer24
Ager CR ··· Dallos MC
Cell Rep Med, 2026
tumorflow↓ sig.significant reduction
depletion
ModerateSome concerns
small-nopen-labelno-multiplicity-correctionindustry-sponsored
PMID PMCID DOI NCT critique41759531randomized-controlledPer trialFOXP3+ (scRNA-seq + CyTOF)frequency-of-CD4early-on-treatmentBaseline vs pre-surgeryPer-arm baseline TI-Treg frequency; density values not tabulated in text (figure panels only)ADT+BMS-986218 arm significantly reduced TI-Treg frequency vs ADT alone (p=0.031); ADT alone arm had INCREASED TI-Tregs vs untreated (p=0.002)Qualitative TI-Treg reduction in combo arm; residual TI-Tregs remained in all tumors (incomplete depletion); numeric density values in figure panels without text quantificationp=0.031 (ADT+BMS-986218 vs ADT alone); p=0.002 (ADT alone vs untreated, ADT expanded TI-Tregs)Measured at radical prostatectomy (end of neoadjuvant window)mechanism-targetedpmc_full_textAger 2026 CRM — randomized phase 1 BMS-986218 (Fc-enhanced anti-CTLA-4) + ADT vs ADT alone. Full-text backfill 2026-04-23: TI-Treg reduction p=0.031 in combo arm; ADT alone expanded TI-Tregs (p=0.002); residual Tregs remained (partial depletion); CD16a+ macrophage correlation p=0.033. Numeric densities in figure panels not text-quantified. Conflict pair with Sharma 2019 (30054281): Sharma shows non-Fc-enhanced anti-CTLA-4 fails to deplete; Ager shows Fc-enhanced anti-CTLA-4 succeeds — reconciled by Fc-engineering difference.