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Abstract Background Immune-related adverse events disrupt immune checkpoint inhibitor therapy and impact quality of life. Peripheral edema is common among patients with cancer, however the causality of peripheral edema can be unclear in the context of multidrug regimens. Methods PubMed/MEDLINE, Embase, and Web of Science were searched to identify phase 3 randomized controlled trials (RCTs) evaluating immune checkpoint inhibitors reporting peripheral edema incidence. The incidence of edema was calculated according to adverse event, immune checkpoint inhibitor, and treatment patterns. A random-effects meta-analysis pooled odds ratios (ORs) of edema incidence between immune checkpoint inhibitor and non–immune checkpoint inhibitor groups. A systematic review characterizing the interventions for immune-related peripheral edema was also conducted. Results From 58 RCTs (22 590 patients), treatment-related peripheral edema (grade 1-5) occurred in 2.80% (n = 195 of 6969) of patients receiving immune checkpoint inhibitor monotherapy, 4.96% (n = 112 of 2257) of patients receiving immune checkpoint inhibitor with chemotherapy, and 8.73% (n = 205 of 2349) of patients receiving immune checkpoint inhibitor with targeted therapy. Meta-analysis showed immune checkpoint inhibitor monotherapy had lower treatment-related peripheral edema incidence compared with chemotherapy (OR = 0.45, 95% CI = 0.27 to 0.73; P = .001, I2 = 69%) with the lowest relative incidence among programmed cell death protein 1 vs chemotherapy (OR = 0.41, 95% CI = 0.23 to 0.73; P = .003) and immune checkpoint inhibitor vs taxane chemotherapy (OR = 0.32, 95% CI = 0.18 to 0.58; P < .001). A systematic review of treatment outcomes for immune-related peripheral edema among 40 patients (19 studies) revealed 82.5% (n = 33 of 40) of cases received glucocorticoid treatment, and immune checkpoint inhibitors were permanently discontinued in 35% (n = 14 of 40). Conclusions Peripheral edema is a rare but potentially serious adverse event associated with immune checkpoint inhibitors. Immune checkpoint inhibitors likely confer less peripheral edema risk than taxane therapy. To avoid unnecessary treatment interruptions, treatment discontinuation requires careful consideration, particularly when edema develops following immune checkpoint inhibitor combination therapy.

TPS5632 Background: Concurrent chemoradiation therapy (CCRT) is the standard of care for locally advanced cervical cancer (LACC); however, outcomes remain suboptimal in patients with high-risk disease. Recent studies suggest that integration of immunotherapy (IO) with definitive chemoradiation, or induction chemotherapy prior to CCRT improves outcomes. Whether treatment intensification with induction systemic therapy and IO prior to CCRT and IO further improves disease control remains unknown. Induction chemotherapy may reduce tumor burden, eradicate micrometastatic disease, and improve tumor immunogenicity prior to definitive CCRT. Preclinical and clinical data support synergy between systemic therapy or radiotherapy and immune checkpoint blockade, providing the rationale for evaluating an induction strategy incorporating chemotherapy and immunotherapy before standard CCRT with immunotherapy, followed by maintenance immunotherapy. Optional tumor tissue and blood samples will be collected for exploratory correlative analyses, including immune and molecular biomarkers associated with response, resistance, and patterns of failure. Methods: NRG-GY037 is a prospective, multi-institutional phase III randomized trial conducted through NRG Oncology. A total of 336 patients will be enrolled (168 per arm). Patients will be stratified by FIGO stage (III vs. IVA) and presence or absence of para-aortic lymph nodes (N2). The primary endpoint is progression free survival (PFS). The study has 90% power to detect PFS hazard ratio of 0.65 in the experimental arm. Treatment: Patients with previously untreated, high-risk LACC are randomized to receive either induction chemotherapy with pembrolizumab for 6 weeks followed by CCRT with pembrolizumab and pembrolizumab maintenance, or standard CCRT with pembrolizumab followed by pembrolizumab maintenance. Major Eligibility Criteria: Eligible patients have histologically confirmed cervical carcinoma (squamous, adenocarcinoma, or adenosquamous), TNM T3 and T4 disease, N0-2, ECOG performance status 0–1, and no prior definitive therapy for cervical cancer. Current Enrollment Status: The trial is actively accruing patients. No efficacy or safety data are available at the time of submission. Clinical Trial Registration: ClinicalTrials.gov identifier: NCT07061977. Clinical trial information: NCT07061977 .

e23419 Background: Current risk assessment for cancer-associated thrombosis remain suboptimal in NSCLC, likely due to unaccounted tumor-specific biology. Although ALK and ROS1-positive NSCLC share closely related structure and elevated thrombotic risk, real-world data on thromboembolic outcomes remain limited. Methods: This multicenter retrospective study was conducted using TriNetX, a global federated health research network;14 of 113 healthcare organizations contributed to analysis. Adults (≥18 years) with NSCLC ROS1 or ALK from 2012-2025 were included. Index event was defined as the first documented NSCLC diagnosis. Outcomes included cumulative incidence, Kaplan–Meier survival analysis (KMS), and event recurrence for arterial thromboembolism (ATE), deep vein thrombosis (DVT), and pulmonary embolism (PE). Analyses were conducted pre and post-propensity score matching (PSM) adjusted for age and sex. Subgroup analyses evaluated outcomes at 1, 3, 6, and ≥12 months. Results: 3,310 NSCLC patients were identified (ALK n=3,155; ROS1 n=155). Mean age was 73 years, with 52.8% female and 46.2% male; 72.5% White, 12.7% Black, 9.5% Asian; South (49%), Northeast (29%). ALK NSCLC were older than those with ROS1 (mean 68.9 vs 64.6 years, p<0.0001), with similar sex distribution. ROS1 had higher proportion of White (85% vs 72%), while ALK included more Asian and Black. Median follow-up prior to matching was 482 days for ROS1 (post-PSM:482) and 546 days for ALK (post-PSM:601) Incidence proportions in ROS1 NSCLC were 12.3% for ATE, 9.7% for DVT, and 12.9% for PE (vs. ALK: 22.6% for ATE, 12.5% for DVT, 11.8% for PE) For ATE, prior to PSM, ROS1 NSCLC demonstrated a significantly lower risk compared with ALK (16.6% vs 25.0%), with an absolute risk difference of −8.4% (95% CI −14.7 to −2.2; p=0.02) and relative risk of 0.66 (95% CI 0.46–0.96). KMS showed longer ATE-free survival in ROS1 compared to ALK (48.2% vs 44.5%, p=0.01; HR 0.60, 95% CI 0.40–0.91, p=0.04). After PSM, overall ATE risk difference did not reach statistical significance, although ROS1 continued to demonstrate lower risk (16.6% vs 25.8%; risk difference −9.2%, p=0.06). Notably, in the subgroup analyses, this significant risk difference emerged ≥12 months, with improved late ATE-free survival in ROS1(91.1% vs 80.3%, p=0.01). For VTE and PE, no significant differences in risk, survival analyses or recurrence, were observed between ROS1 and ALK before or after PSM (DVT risk: 9.2% vs 9.7% pre-PSM; 9.2% vs 10.1% post-PSM; PE: 11.2% vs 9.9% pre-PSM; 11.2% vs 8.6% post-PSM; all p>0.05). Conclusions: Arterial thromboembolism differed by oncogenic subtype, with higher ATE risk in ALK compared with ROS1-positive NSCLC, particularly ≥12-months. In contrast, no significant difference in venous thromboembolism and pulmonary embolism were observed; further validation in prospective studies is warranted.

e14545 Background: Durable antitumor immunity depends on the maintenance of stem-like CD8⁺ T cells capable of sustaining long-term effector responses. Oncolytic viruses (OVs) are potent immunomodulatory agents that reshape the tumor microenvironment and augment antitumor immunity. We hypothesized that platinum-based chemotherapy alters tumor-intrinsic type I interferon (IFN-I) signaling in a manner that can be functionally restored by OV therapy, thereby promoting the generation and persistence of stem-like CD8⁺ T cells. Methods: Tumor cells treated with platinum chemotherapy were evaluated in vitro for changes in IFN-I pathway activity, OV replication, and markers of immunogenic cell death (ICD). Syngeneic mouse tumor models were used to assess antitumor efficacy and immune remodeling following combination therapy. Tumor-infiltrating lymphocytes were analyzed by single-cell RNA sequencing and multiparameter flow cytometry to define CD8⁺ T-cell states and functional programs. Guided by these preclinical findings, a clinical trial combining XELOX, PD-1 blockade, and OV therapy was initiated (ChiCTR2500107607). Results: Platinum chemotherapy significantly suppressed tumor-intrinsic IFN-I signaling, while OV therapy restored antiviral responses, enhanced viral replication, and increased ICD in vitro. In vivo, the combination strategy resulted in superior tumor control and profound remodeling of the tumor immune microenvironment. The most pronounced immunologic effect was observed within the stem-like CD8⁺ T-cell compartment. Combination therapy induced a distinct population of TCF7⁺ ISG15^high NFATC1^low AP-1^low CD8⁺ T cells, characterized by restrained activation, enhanced persistence, and reduced propensity toward terminal exhaustion. In IRF7-deficient tumors, this stem-like CD8⁺ T-cell population failed to emerge and antitumor efficacy was significantly diminished, indicating that moderate tumor-intrinsic IFN-I signaling is required for this immune state. Conclusions: Tumor-intrinsic type I interferon signaling is a critical determinant of synergy between platinum chemotherapy and oncolytic virotherapy, enabling the maintenance of durable stem-like CD8⁺ T-cell immunity. These findings establish a mechanistic rationale for combining platinum chemotherapy, oncolytic viruses, and immune checkpoint blockade and support ongoing clinical translation. Clinical trial information: ChiCTR2500107607.

e13677 Background: The development of AI led to the emergence of tools such as AIS, which have been increasingly adopted in medicine. However, formal evaluation of barriers and clinical care gaps in HemOnc is limited, particularly regarding treatment plan complexities and toxicity documentation. Methods: Structured investigator-developed surveys about AIS availability, adoption, benefits, and challenges were developed on Qualtrics and approved by the IRB. HemOnc faculty physicians (FP), advanced practice providers (APP), and trainees (HOT) were surveyed between 11/14/25-1/16/26. Surveys were distributed in the USA via email, social media (on X), and ASCO myConnection. Descriptive statistics were used for analysis. Results: 132 participants responded to the survey: 55 FP (42%), 14 APP (11%), and 63 HOT (48%). 80% of them reported having AIS at their institutions, and 54% of those reported using these tools in their clinical practice. Among FP and APP, 72% practiced in academic settings, 14% in community, and 13% in hybrid centers. Among those not using AIS, identified barriers were issues with note formatting (56%), lack of training (25%), and concerns that the note content is incorrect or inadequate (25%). 60% are willing to use AIS if note formatting matched their preference, and 42% would try it if contents better reflected the patient encounter. Table 1 details the proportion of encounters using AIS, the portion of documentation it was used for, and the perceived challenges with these tools. Among AIS users, the average satisfaction score was 5.3 on a 7 point scale, corresponding to participants being somewhat satisfied. Participants agreed slightly that AIS had reduced their feeling of work-related burnout, with an average score of 3.6 on a 5 point scale. Overall, participants felt neutral about how well-suited AIS are for HemOnc, with an average score of 4.0 on a 7 point scale. Conclusions: Despite AIS being widely available, 46% of the surveyed HemOnc workforce do not use them in clinical practice. Those who do reported decreased time spent on documentation outside work hours and a slight reduction in the feeling of burnout. Formatting issues and record integration remain barriers, with substantial concerns about AIS not adequately describing HemOnc treatment plans. To bridge the last mile of integration into HemOnc, partnership between AIS developers and the clinical workforce is essential to meet clinical needs, while prioritizing patient safety and data privacy. FP + APP % HOT % Patient encounters where AIS is used 62 44 Used AIS for the subjective portion of note 68 96 Used AIS for the assessment/plan portions of note 40 25 AIS decreased the time on clinical documentation outside work hours 96 93 AIS note formatting needs improvement 68 57 Issues integrating AIS and outside records 46 71 AIS note contents about the plan are suboptimal 32 61

7528 Background: Lenalidomide (Len) maintenance after ASCT has been a standard of care for patients (pts) with MM. Historically, ~30% of pts discontinue Len within 1 year (yr) due to toxicity and there is a need for more effective and better tolerated maintenance strategies. Iber is a potent, oral cereblon E3 ligase modulator under evaluation in the relapsed/refractory and newly diagnosed settings. We report the results of the primary analysis of a Phase II trial of Iber maintenance following upfront ASCT. Methods: Pts ≥ 19 yrs of age with MM, within 1-yr of initiation of induction therapy and in a ≥ partial response (PR) at day 80-110 post-ASCT, were accrued. Iber was administered 1.0 mg orally days 1-21 of a 28-day cycle, continued until progressive disease (PD) or toxicity. Up to 2 dose reductions (0.75 mg/day then 0.6 mg/day) were allowed. Growth factor support was not permitted. Minimal residual disease (MRD) assessment by flow cytometry (10 -5 ) was performed at registration, post-cycle 12 and post-cycle 24. An optimal Simon two-stage design with type I and II errors of 0.1 was chosen to test whether the proportion of pts who are progression-free and on treatment at 1 yr is <60% against the alternative of ≥ 80%. If ≥ 27 out of 38 pts were progression-free (by 2016 IMWG criteria) and on treatment at 1 yr, Iber would be considered to have promising activity. Results: 38 pts (55% males, median age 61 yrs (range: 41-77)) received Iber. R-ISS at diagnosis was stage I (34%), II (39%), III (8%) and unknown (18%), with 34% having high-risk disease per 2025 IMS/IMWG criteria. All pts received triplet or quadruplet induction therapy, with 97% receiving Len and 84% receiving daratumumab. At day 80-110 post-ASCT, all pts had ≥ very good PR, with 22 (58%) ≥ complete response (CR) and 33 (87%) MRD-negative (neg). The median number of administered treatment cycles is 18 (range: 1-45), with 18 (47%) pts having ≥ 1 dose reduction, most commonly due to neutropenia (n=12). The most common grade (gr) 3/4 adverse event was neutropenia (gr 3 (n=19), gr 4 (n=5)). Within yr 1, 29% (11/38) discontinued Iber due to neutropenia (n=5), rash (n=1), infection (n=1), pt choice (n=1), or PD (n=3). After 1 yr, 6 pts discontinued due to neutropenia (n=4) and PD (n=2). While on Iber, 19 pts had deepening of response to stringent CR and 3 pts converted from MRD-positive to MRD-neg. The post-cycle 12 and 24 MRD-neg rates are 85% (23/27) and 100% (14/14), respectively. Conclusions: Iber demonstrated promising activity with dose reductions/discontinuations mainly due to neutropenia. Strategies including lower starting dose, growth factor support and more flexible management of neutropenia may enable more pts to remain on treatment. Longer follow-up will permit evaluation of sustained MRD-negativity and PFS, but overall, these results provide rationale for further exploration of Iber-based post-ASCT maintenance strategies. Clinical trial information: NCT05177536 .

7094 Background: Waldenström Macroglobulinemia (WM) remains incurable with current available therapeutic options. Treatment options for relapsed/refractory pts are limited and often continuous, underscoring the need for new agents with novel mechanisms of action and pt-centered, fixed duration therapy. Iopofosine I 131 is a novel radiopharmaceutical compound composed of a lipid raft-targeting phospholipid ether covalently bound to 131 I, a beta emitting radioisotope. Here, we report preliminary sub-group results of the CLOVER-WaM study [NCT02952508] in WM pts treated with a Bruton’s Tyrosine Kinase inhibitor (BTKi) immediately prior to iopofosine. Methods: Eligible WM pts had received >2 prior therapies and had symptomatic disease requiring therapy according to consensus recommendations for WM. Treatment consisted of 2 cycles of iopofosine I 131 administered at 15 mCi/m 2 on days 1 and 15 of each 57-day cycle. The primary efficacy endpoint was major response rate (MRR; partial response or better, as determined by the modified IWWM-VI). Secondary and exploratory endpoints included overall response rate (ORR), treatment-free survival (TFS), progression free survival (PFS), duration of response (DOR), and clinical benefit rate (CBR; stable disease or better). Herein, efficacy endpoints were assessed in the modified intent-to-treat (mITT) population (all pts who received ≥60 mCi total administered dose of iopofosine I 131), and whose treatment regimen prior to iopofosine included a BTKi. Safety was evaluated using CTCAE v4.03 in pts who received ≥1 dose of iopofosine. Data cut off for this analysis was Jan. 16, 2026. Results: As previously reported, 65 pts were dosed and 55 are included in the mITT population. Of those, 22 (40%) had received a BTKi containing regimen immediately prior to iopofosine; and 11 who previously received at least 2 regimens utilizing BTKis and 12 who were refractory to rituximab. In this subgroup, median age was 70.5 (range 55-88), 17 (77%) were male, and 5 (23%) were female. The median number of prior therapies was 3 (range 2-7), 15/22 (68%) were MYD88 mutated and 18/22 (82%) were TP53 wildtype. The MRR was 15/22 (68.2%), ORR was 19/22 (86.4%) and CBR was 100%, median PFS was 12 months (range 1.6 to 28.0) and median TFS was 19.1 months (range 2.5-34.4). Grade ≥ 3, related treatment emergent adverse events (TEAE) occurring in > 10% of pts included anemia (41%), leukopenia (41%), neutropenia (58%), and thrombocytopenia (86%). Conclusions: Iopofosine I 131 demonstrated significant efficacy; 100% CBR, 86.4% ORR and 68.2% MRR with a median PFS of 12 months (range: 1.6 – 28.0 months) in a pt population with no current standard of care therapy. The treatment was well-tolerated with a manageable toxicity profile with cytopenias as the only Grade 3 or greater TEAE. Based on the results of this pivotal trial, iopofosine I 131 could be a promising novel treatment for WM pts after BTKi therapy. Clinical trial information: NCT02952508 .

7028 Background: Axi-cel, autologous anti-CD19 CAR T-cell therapy, showed long-term survival and curative potential in R/R LBCL (ZUMA-1; Neelapu et al. Blood . 2023). Few studies have examined long-term outcomes beyond clinical trials. Here we report long-term real-world outcomes of axi-cel in R/R LBCL using large-sample CIBMTR data. Methods: A total of 1500 adults from 79 US centers receiving commercial axi-cel after ≥2 LOT for LBCL from Oct 2017-Aug 2020 were enrolled in a post-marketing requirement study. A protocol was developed prior to the study’s implementation, reviewed by Kite and CIBMTR. This is a secondary analysis of said study. Key outcomes were progression-free survival (PFS), overall survival (OS), time to next therapy (TTNT), disease-specific mortality (competing risks were non-relapse deaths), subsequent malignancies, and non-relapse mortality (NRM). Outcomes were analyzed descriptively. Cases with missing data were excluded separately for each endpoint. Results: As of Aug 2025, 1446 patients (pts) were included in the analysis. Median age at infusion was 62.2 y (range, 19.6-90.8: 38% of pts ≥65 y); 65% were male. Five percent of pts had ECOG PS ≥2 and 16% had high-grade lymphoma. Pts had a median of 3 (range, 2-4) prior LOT, 28% had prior autologous hematopoietic cell transplantation, and 50% received bridging therapy. At 59.7 mo median follow-up, median PFS (95% CI) was 7.9 mo (6.3-10.9) and 5-y PFS was 30% (27-32). The median OS was 25.7 mo (21.6-30.2); 5-y OS was 38% (35-41). The 5-y cumulative incidence of disease-specific mortality was 51%. Among pts who were progression-free at 2, 3, 4, or 5 y post-infusion, the OS at 6 y (95% CI) was 73% (68-78), 81% (76-86), 90% (84-94), and 94% (89-97), respectively. The median duration of response (DOR) was 25.3 mo (95% CI, 20.7-32.8) and 5-y DOR was 38% (35-41). The median TTNT was 12.2 mo and 30% did not need additional LOT at 5 y. Of pts who received subsequent salvage therapy, 12 (2%) received cell therapy, 39 (7%) received hematopoietic cell transplant, and 475 (90%) received other therapy. The 1, 2, 3, 4, and 5-y cumulative incidence of relapse (95% CI) was 49% (46-51), 52% (50-55), 54% (52-57), 55% (53-58), and 56% (53-59), respectively. No new safety signals were observed. The primary causes of death (n=864; 60%) were primary disease (540; 63%), infection (111; 13%), and organ failure (57; 7%). The 5-y cumulative incidence of NRM was 16% (95% CI, 14-18). At 5 y, 11% (95% CI, 10-13) had subsequent malignancies, mostly therapy-related myeloid neoplasms (6%) and non-melanoma skin cancer (3%); none were directly attributed to axi-cel. Conclusions: This real-world study showed sustained survival at 5 y among pts with R/R LBCL treated with axi-cel after ≥2 LOT, consistent with ZUMA-1. Infection and organ failure were common causes of NRM. These results continue to support the use of axi-cel with curative intent in R/R LBCL.

4235 Background: Malignant portal vein tumor thrombus (PVTT) arising from hepatic metastases is associated with poor prognosis, rapid hepatic decompensation, and limited effective local treatment options despite systemic therapy. In real-world practice, local treatment intensity is frequently adapted to disease burden and treatment response. We evaluated outcomes of a risk-adapted, step-up local treatment strategy using microwave ablation (MWA) alone or in combination with iodine-125 (I-125) seed implantation for patients with malignant PVTT. Methods: We retrospectively reviewed patients with hepatic metastases treated with MWA with or without I-125 seed implantation between 2023 and July 2025. In clinical practice, MWA alone was preferentially used for patients with relatively limited disease burden, while MWA plus I-125 was employed as an escalation strategy for patients with more advanced PVTT or disease progression following MWA alone. The primary endpoint was PVTT-directed local outcome, defined as portal vein patency and/or local control of tumor thrombus on follow-up imaging. Secondary endpoints included progression-free survival (PFS), overall survival (OS), hepatic function changes, and treatment-related toxicity. Survival analyses were considered exploratory. Results: A total of 73 patients were included, of whom 50 were treated with MWA alone and 23 with MWA plus I-125 seed implantation. Patients receiving MWA plus I-125 demonstrated more advanced disease characteristics, including universal presence of PVTT and higher disease stage, consistent with treatment escalation by disease severity. Among patients with PVTT, MWA plus I-125 achieved portal vein patency and/or local control in 65% at first follow-up imaging. Treatment-related toxicities were manageable, with no unexpected grade ≥3 adverse events attributable to I-125 implantation. Median PFS was 11.5 months in patients treated with MWA alone and 9.9 months in patients treated with MWA plus I-125, consistent with greater baseline disease burden in the latter group. Conclusions: MWA alone and MWA plus I-125 function as complementary components of a risk-adapted, step-up local treatment strategy for malignant PVTT from hepatic metastases. Escalation to MWA plus I-125 appears feasible in patients with advanced or refractory PVTT and demonstrates a potential signal for improved PVTT-directed local control and portal vein patency. Prospective studies focused on PVTT-specific endpoints are warranted.

11127 Background: Immune-related adverse events (irAEs) often require treatment discontinuation in patients with cancer receiving immune checkpoint inhibitors (ICIs). Given limited subsequent treatment options, ICI rechallenge is frequently considered. We aimed to estimate the incidence of recurrent irAEs and objective response rates (ORR) in patients receiving ICI rechallenge following prior irAEs. Methods: PubMed, Web of Science, and Embase were searched for studies evaluating ICI rechallenge in patients with advanced solid tumors who previously suspended treatment due to irAEs. Outcomes included the incidence of grade 1-5 (Gr1-5), Gr1-2, and Gr3-5 irAEs, recurrent irAEs, new irAEs, ORR, and disease control rate (DCR). Random-effects meta-analyses and subgroup analyses by cancer type were performed. Meta-regression analysis was conducted to evaluate the impact of the grade and type of initial irAEs on response outcomes. Heterogeneity was assessed using I 2 statistics (≥50% considered high). Results: Thirty-seven studies comprising 1,126 patients with initial irAEs (Gr1-2: 62.8%, Gr3-4: 37.2%) leading to suspension of ICIs were included. The most common initial irAEs in the pooled cohort were hepatitis/liver enzyme elevations (20.5%), pneumonitis (16.1%), and nephritis/acute kidney injury (14.8%). Pooled incidences of Gr1-5, Gr1-2, and Gr3-5 irAEs after ICI rechallenge were 42.2% (95% confidence interval [CI]: 35.3-49.3), 27.1% (95% CI: 22.9-31.7), and 18.8% (95% CI: 14.7-23.8), respectively. Subgroup analysis showed overall higher incidences of irAEs in melanoma (Gr1-5: 54.6%, Gr1-2: 23.2%, Gr3-5: 26.4%) than those in lung cancer (Gr1-5: 39.7%, Gr1-2: 27.4%, Gr3-5: 14.0%) and solid tumors (Gr1-5: 36.7%, Gr1-2: 22.8%, Gr3-5: 20.1%). The same type of irAEs recurred in 23.8% (95% CI: 20.1-28.0) of patients, while new types of irAEs developed in 29.3% (95% CI: 25.2-33.7) of patients undergoing ICI rechallenge. The overall ORR was 45.2% (95% CI: 34.5-56.4), with cancer type-specific ORRs of 60.5% (95% CI: 47.9-71.9) in melanoma, 39.1% (95% CI: 17.4-66.2) in lung cancer, and 39.5% (95% CI: 27.7-52.6) from studies investigating solid tumors. DCR was high across cancer types: 77.3% (95% CI: 67.7-84.7) overall, 68.2% (95% CI: 41.3-86.8) in melanoma, 91.2% (95% CI: 67.7-98.1) in lung cancer, and 72.5% (95% CI: 63.3-80.1) in solid tumors. Meta-regression analysis showed that commonly observed initial irAE types or grades of initial irAEs (Gr1-2 vs. Gr3-4) did not significantly impact ORR or DCR. Conclusions: ICI rechallenge after discontinuation due to irAEs demonstrates clinical activity but carries a substantial risk of both recurrent and new irAEs. These findings highlight the need for predictive biomarkers to optimize patient selection and maximize survival without compromising safety.