Long-term Responders Research Articles

CTIM-23. A PHASE II STUDY OF RETIFANLIMAB (PD-1 INHIBITOR) AND EPACADOSTAT (IDO1 INHIBITOR) IN COMBINATION WITH BEVACIZUMAB AND HYPOFRACTIONATED RADIOTHERAPY FOR RECURRENT GLIOBLASTOMA: NCT03532295

Abstract INTRODUCTION Immunotherapy has not improved survival in recurrent GBM (rGBM). Indoleamine 2,3 dioxygenase 1 (IDO1), highly expressed in ~90% of patients with malignant glioma, is a rate-limiting enzyme that catabolizes tryptophan (Trp) into kynurenine (Kyn) and enables immune escape. METHODS We hypothesized combining therapies targeting immunosuppressive pathways with cytotoxic and antiangiogenic therapies would overcome tumor-related immunosuppression. This was an open-label Phase II study of two regimens: Arm A consisted of retifanlimab (anti-PD1, 500mg IV Q4W) + bevacizumab (10mg/kg IV Q2W) + HFRT (3.5Gy/day x 10) in patients with IDH1/2-WT rGBM. Regimen B added the IDO inhibitor, epacadostat (400mg po BID), initiated prior to HFRT. Key inclusion criteria included dexamethasone ≤ 4 mg/day. The primary endpoint was overall survival (OS) at 9 months (OS-9). 24 evaluable patients were required to detect an OS-9 of 60% with 80% power, compared to 38% in historical controls (bevacizumab alone) by 1-sided 1-sample log rank test at alpha=0.1. RESULTS We previously reported Arm A. Here, we present results from Arm B. 25 of the 27 patients enrolled to regimen B were evaluable: median age 58years (23-71); 28% female; 23% MGMT promotor methylated; median KPS 90 (70 - 100); a median of 6 cycles of epacadostat as of May 2024 (1 - 13). 18 of 25 died with a median follow up 9.23 months. Median PFS was 7.52 months (95%CI: 5.52-9.43). Median OS was 9.5 months (95%CI 8.08-11.96). Regimen B met its primary endpoint with OS-9 of 61.07% (95%CI: 38.23-77.65%). There were 5 possible immune-related grade 3+ toxicities to date (2 ALT/AST increase; 3 rash). CONCLUSIONS Retifanlimab, epacadostat, HFRT, and bevacizumab in rGBM is well-tolerated, with encouraging OS and PFS at the time of submission. Arm B met its primary endpoint. Further studies are warranted to identify biomarkers to predict long-term responders.

BIOM-58. RE-INDUCTION OF INTRATHECAL CHEMOTHERAPY IN PRIOR RESPONDERS AND CORRELATION WITH CEREBROSPINAL FLUID CIRCULATING TUMOR CELLS

Abstract INTRODUCTION Leptomeningeal carcinomatosis (LMC) is an aggressive form of metastasis, with a historically poor median overall survival. Newer therapies and treatment strategies are improving outcomes, and more long-term responders exist. However, there are limited options for intrathecal (IT) chemotherapy, and re-induction in prior responders may be a reasonable treatment strategy. In addition, quantitative cerebrospinal fluid circulating tumor cells (CSF CTCs) are a valuable tool in LMC, for both surveillance of recurrence and evaluation of response. METHODS We retrospectively identified 10 patients with LMC who showed a response to IT chemotherapy and were followed with quantitative CSF CTCs on a commercially available platform. At progression, patients underwent re-induction of IT chemotherapy, on a twice a week schedule, and were evaluated for response. RESULTS All 10 patients were treated with re-induction IT chemotherapy. Six patients were re-challenged with topotecan, 3 with topotecan + trastuzumab, and 1 with pemetrexed + trastuzumab. Six patients had a primary diagnosis of breast cancer, three with lung cancer and one with ovarian cancer. The median KPS was 70. Eight were female. Prior to re-induction, all 10 had an increase in quantitative CSF CTCs. Only 1/10 had new symptoms, and 5/10 showed imaging changes on MRI. At the time of re-induction, 3/10 also received stereotactic radiosurgery to brain metastases and 2/10 had a change in systemic chemotherapy. 9/10 had improved CSF CTC counts on the next restaging, typically at 8 weeks. The median overall survival from re-challenge was 12.7 months. CONCLUSION Quantitative CSF CTCs were a more sensitive predictor of recurrence than symptoms or imaging, and were a marker of response to re-induction IT chemotherapy. Re-induction showed a durable survival benefit, and is a reasonable treatment strategy in patients who were prior responders

Longer-term safety and efficacy of baricitinib for atopic dermatitis in pediatric patients 2 to

Background Baricitinib, an oral selective Janus kinase inhibitor, improved clinical signs and symptoms of moderate-to-severe atopic dermatitis (AD) at week 16 in the phase 3 pediatric study BREEZE-AD-PEDS. Objective To assess longer-term efficacy and safety of baricitinib in pediatric patients aged 2 to <18 years. Methods In BREEZE-AD-PEDS long-term extension, responders and partial responders (validated Investigator Global Assessment-Atopic Dermatitis [vIGA-AD®] 0/1/2) at Week 16 remained on double-blind treatment to which they were randomized (placebo, baricitinib [1-mg equivalent, 2-mg equivalent, or 4-mg equivalent); non-responders (vIGA-AD 3 or 4) at Week 16 transitioned to open-label baricitinib 4-mg equivalent. Safety was summarized for all randomized patients who received ≥1 dose of study treatment. Results In total 467 patients received baricitinib for 750.7 patient-years. Proportion of responders/partial responders (at Week 16) who achieved vIGA-AD 0/1 at Week 52 was greater for baricitinib 4-mg equivalent (56.8%) versus all other treatment groups (42.2%, 47.7%, and 39.7% for 2-mg equivalent, 1-mg equivalent, and placebo, respectively). Most treatment-emergent adverse events were mild/moderate in severity. No deaths, pulmonary emboli, deep vein thromboses or arterial thrombotic events, major adverse cardiovascular events, malignancies, tuberculosis events, or gastrointestinal perforations were reported. Conclusions Baricitinib demonstrated sustained long-term efficacy. No new safety signals were identified. Trial Registration ClinicalTrials.gov Identifier: NCT03952559

Effectiveness of long-term bimekizumab treatment and predictive factors for responders in moderate-to-severe psoriasis: A 52-week real-world study.

Psoriasis is a chronic, inflammatory skin disease in which the interleukin (IL)-23/IL-17 axis plays a central role. Bimekizumab is a novel antibody that targets both IL-17A and IL-17F. This retrospective study aimed to assess the long-term effectiveness and safety of 52-week treatment with bimekizumab, and to identify predictive factors for short- (16 weeks) and long-term (52 weeks) responders (i.e., achievers of a Psoriasis Area and Severity Index (PASI) score of 100) to bimekizumab in Japanese patients with psoriasis. The study was conducted on 56 Japanese patients (aged ≥ 15 years) with moderate-to-severe psoriasis treated with bimekizumab from May 2022 to March 2024. The therapeutic effectiveness was evaluated by the transition of PASI scores during treatment. Baseline characteristics and clinical and laboratory indexes were compared between responders and poor responders. Treatment-emergent adverse events (TEAEs) were recorded to assess the safety of the treatment. At week 52, the achievement of PASI 100, static Physician's Global Assessment 0/1, and the Dermatology Life Quality Index 0/1 were 72.4%, 94.7%, and 93.3%, respectively. Short-term responders showed lower baseline values of neutrophil-to-lymphocyte ratio, monocyte-to-lymphocyte ratio (MLR), and systemic inflammatory response index compared to poor responders. Long-term responders showed younger age and lower MLR compared to poor responders. TEAEs were mild or moderate, without serious adverse events. Long-term treatment with bimekizumab is effective and safe for psoriasis patients. Lower MLR and younger age might predict long-term response to treatment with bimekizumab, aiding in personalized treatment strategies.

Long-term Responders to Nanoparticle Albumin-bound Paclitaxel Following Immune Checkpoint Inhibitor in Non-small Cell Lung Cancer.

The efficacy of cytotoxic chemo-therapy has been reported to improve after immune checkpoint inhibitor (ICI) administration. We previously conducted a multicenter prospective clinical study to evaluate the efficacy and safety of nanoparticle albumin-bound paclitaxel (nab-PTX) after ICI treatment. In that study, some patients showed a long-term response to nab-PTX, which is not usually observed with single-agent chemotherapy. The present study aimed to evaluate the clinical characteristics of these patients. We retrospectively analyzed updated data from 29 patients enrolled in our clinical study who received nab-PTX monotherapy after ICI treatment. We defined a "long-term responder" as a patient who achieved a 1-year progression-free survival (PFS). Among the 29 patients, 10 (34.5%) were long-term responders, two of whom achieved a 5-year PFS. A key difference between long-term and non-long-term responders was that the long-term responders had a significantly higher number of patients with Eastern Cooperative Oncology Group-performance status of 0 (70.0% versus 10.5%; p=0.002). Furthermore, median cycles of previous ICIs and median treatment cycles were significantly higher in long-term responders than in non-long-term responders (8 cycles versus 3 cycles; p=0.03) (5.9 months versus 2.0 months; p=0.02). In the 10 long-term responders, six patients required at least a one-stage dose reduction owing to adverse events, and four patients required a two-stage dose reduction. Nab-PTX administration after ICI treatment may elicit a long-term response. A long-term response can be achieved even with a dose reduction due to adverse events.

Cardiopulmonary exercise testing in long-term calcium channel blockers responders, does it normalize in the same way as pulmonary vascular resistance?

Abstract Background and aims Long-term calcium channel blockers (CCB) responders represent &amp;lt;10% of pulmonary arterial hypertension (PAH) patients and are known to have an excellent prognosis on high dose CCB. The few reports of lung histology of these patients suggest a predominant muscular thickening of the precapillary arterioles. Nevertheless, the classic intimal proliferation characteristic of PAH has also been reported, although to a lesser extent. Hence, we hypothesized that long-term CCB responders are likely to exhibit some degree of ventilatory inefficiency as a result of their impaired alveolo-capillary membrane. In this study, we aimed to evaluate the exercise performance of a contemporary cohort of long-term responders to CCB in terms of both exercise capacity and ventilatory efficiency, and whether there are differences depending on the haemodynamic severity. Methods We evaluated all long-term CCB responders with regular follow-up at our institution between 1996 to 2024 with at least one cardiopulmonary exercise test (CPET) and a right heart catheterization (RHC) within a three-year period, provided they had remained clinically stable without changes in pulmonary vasodilator treatment. Patients with additional PAH specific treatment were excluded. For data analysis purposes, the population was divided into 2 groups according to pulmonary vascular resistance (PVR). The cut-off point for PVR was set at ≥3. Results Twenty-four patients (91,6% female) with complete data were retrospectively enrolled. Baseline characteristics were as follows: median age 45.5 years (59-33) median mean pulmonary artery pressure of 26 mmHg (29-24) and median PVR of 3 WU (3-2.6). Regarding the whole cohort, peak oxygen consumption (pVO2) revealed mild impairment of functional capacity (mean pVO2: 1281 ± 245 ml/kg – 75 ± 15% of predicted). Ventilatory efficiency parameters were also mildy affected with low end-tidal carbon dioxide pressure at the anaerobic threshold (PETCO2@AT) (33.7±3.6mmHg), and increased minute ventilation (VE)/carbon dioxide output (VCO2) slope (33.5±4.5). The subgroup analysis depending on PVR showed no significant differences between groups in terms of pVO2 (1291.9 ±240 Vs. 1150 ±350 ml/kg, p:0.29 / 79%±16 vs 67%±12, p:0.8), VE/VCO2 slope (33 Vs. 34, p:0.21), or PETC02@AT (35 Vs. 33 mmHg, p:0.25). All CPET parameters by subgroups are displayed in Table 1. Conclusions Long-term CCB responders exhibit mildly reduced functional capacity. Moreover, they often fail to normalize the ventilatory efficiency parameters in most of the cases, even when PVR reaches close to normal values, suggesting persistent endothelial impairment.Results according to PVR

A 14-year retrospective of HER2 + metastatic breast cancer treatment at one comprehensive cancer center: Impact of the trastuzumab/pertuzumab and trastuzumab-emtansine sequence versus trastuzumab on overall survival.

Introduction: Monoclonal antibodies represent a significant improvement in the treatment of the HER2 + metastatic cancer, which is associated with a worse prognosis. The objective of this study was to compare overall survival (OS) data in patients treated with trastuzumab + pertuzumab followed by trastuzumab-emtansine (T-DM1) in the second line of metastatic treatment (Arm A) versus patients treated with trastuzumab alone (Arm B). Progression-free survival (PFS) in first-line metastatic patients was also compared in both arms. Methods: This single-center retrospective study included patients from February 2008 to August 2022. OS and PFS of both arms were described and estimated using the Kaplan-Meier method. Data were extracted from electronic medical records and CHIMIO prescribing software. Results: The total duration of metastatic treatment of the 82 patients was significantly longer in the arm A (43.2 ± 28 months vs 33.6 ± 28.9 months), as was the median time to death (59 vs 52 months). The OS data showed a significant reduction in the risk of death in the arm A (Hazard Ratio = 0.59; 95% Confidence Interval [0.37-0.94]; p = 0.02). No difference was shown for PFS. Conclusion: The trastuzumab/pertuzumab/T-DM1 combination showed a significant improvement in OS. Our results are in line with the CLEOPATRA and EMILIA studies, but long-term responders in the arm A may have impacted our results. The absence of difference in term of PFS in first metastatic line may be explained by a selection bias, as patients in the arm A potentially have more aggressive forms.

Personalized treatment approach for HER2-positive metastatic breast cancer.

Breast cancer (BC) is a leading global concern for women, with 30% being HER2-positive cases linked to poorer outcomes. Targeted therapies like trastuzumab deruxtecan (T-DXd), trastuzumab, pertuzumab, and T-DM1 have revolutionized HER2-positive metastatic breast cancer (MBC) treatment. Although these therapies have improved MBC management and patient outcomes, resistance can develop, reducing effectiveness. Personalized strategies based on tumor characteristics offer hope for better responses and longer outcomes. This review outlines insights into MBC patients responding well to anti-HER2 treatments, even across multiple treatment regimen. Recent immunotherapy, locoregional therapy, and liquid biopsy breakthroughs are covered, suggesting ways to increase long-term responders. Personalized approaches have boosted HER2-positive MBC outcomes, and ongoing research is crucial to uncover new treatments and biomarkers, potentially elevating long-term response rates and prognoses. This may aid in providing new direction to breast cancer clinics.

757P Sustained long-term responders to niraparib maintenance in recurrent platinum-sensitive high-grade ovarian cancer (PSROC): A subanalysis of the GEICO-88R study

757P Sustained long-term responders to niraparib maintenance in recurrent platinum-sensitive high-grade ovarian cancer (PSROC): A subanalysis of the GEICO-88R study

1334P PET/CT-guided immune checkpoint blocker treatment discontinuation vs treatment continuation in lung cancer long-term responders: A National Network Genomic Medicine Lung Cancer Germany (nNGM) analysis

1334P PET/CT-guided immune checkpoint blocker treatment discontinuation vs treatment continuation in lung cancer long-term responders: A National Network Genomic Medicine Lung Cancer Germany (nNGM) analysis

Definition, classification and diagnosis of pulmonary hypertension.

Pulmonary hypertension (PH) is a haemodynamic condition characterised by elevation of mean pulmonary arterial pressure (mPAP) >20 mmHg, assessed by right heart catheterisation. Pulmonary arterial wedge pressure (PAWP) and pulmonary vascular resistance (PVR) distinguish pre-capillary PH (PAWP ≤15 mmHg, PVR >2 Wood Units (WU)), isolated post-capillary PH (PAWP >15 mmHg, PVR ≤2 WU) and combined post- and pre-capillary PH (PAWP >15 mmHg, PVR >2 WU). Exercise PH is a haemodynamic condition describing a normal mPAP at rest with an abnormal increase of mPAP during exercise, defined as a mPAP/cardiac output slope >3 mmHg/L/min between rest and exercise. The core structure of the clinical classification of PH has been retained, including the five major groups. However, some changes are presented herewith, such as the re-introduction of "long-term responders to calcium channel blockers" as a subgroup of idiopathic pulmonary arterial hypertension, the addition of subgroups in group 2 PH and the differentiation of group 3 PH subgroups based on pulmonary diseases instead of functional abnormalities. Mitomycin-C and carfilzomib have been added to the list of drugs with "definite association" with PAH. For diagnosis of PH, we propose a stepwise approach with the main aim of discerning those patients who need to be referred to a PH centre and who should undergo invasive haemodynamic assessment. In case of high probability of severe pulmonary vascular disease, especially if there are signs of right heart failure, a fast-track referral to a PH centre is recommended at any point during the clinical workup.

Overall Survival, Treatment Duration, and Rechallenge Outcomes With ICI Therapy for Recurrent or Metastatic HNSCC

Immune checkpoint inhibition (ICI) is a frontline treatment for recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC), but questions remain surrounding optimal duration of therapy, benefits and risks of ICI rechallenge, and efficacy in first vs subsequent lines of therapy. To estimate survival in US patients receiving ICI-based treatment for R/M HNSCC, compare outcomes associated with treatment discontinuation vs continuation at 1 or 2 years, and assess outcomes after immunotherapy rechallenge. This retrospective, population-based cohort study included adult patients in the Flatiron Health nationwide oncology database treated with immunotherapy for R/M HNSCC from 2015 to 2023. Data cutoff was August 31, 2023; data analysis was conducted from December 2023 to February 2024. Treatment continuation vs discontinuation at 1 and 2 years; rechallenge with ICI after at least a 60-day period off ICI therapy without intervening systemic treatment (immediate rechallenge), or with intervening systemic treatment (delayed rechallenge). Overall survival (OS) from ICI initiation was analyzed using the Kaplan-Meier method. Cox multivariable regression was used to examine associations of key variables (line of therapy, human papillomavirus [HPV] status, Eastern Cooperative Oncology Group [ECOG] performance status) with survival. The cohort included 4549 patients with R/M HNSCC who received ICI-containing therapy (median [IQR] age, 66 [59-72] years; 3551 [78.1%] male; 56 [1.2%] Asian, 260 [5.7%] Black or African American, 3020 [66.4%] White, 1213 [26.7%] other or unknown race; 3226 [70.9%] ECOG performance status 0 or 1). There were 3000 patients (65.9%) who received ICI in frontline and 1207 (26.5%) in second line; 3478 patients (76.5%) received ICI monotherapy. Median (IQR) OS was 10.9 (4.1-29.1) months and was longer in patients who received ICI in frontline therapy (12.2 [4.8-32.0] vs 8.7 [3.2-22.4] months), had HPV-positive cancer (16.6 [6.5-43.9] vs 8.8 [3.5-24.0] months), and had ECOG performance status 0 or 1 (13.5 [5.2-33.9] vs 5.5 [2.0-13.7] months). There were no survival differences on adjusted analysis between patients who stopped vs those who continued ICI at 1 or 2 years. Median (IQR) OS after ICI rechallenge was 15.7 (13.7-21.9) months in the immediate rechallenge group and 9.9 (3.7-18.1) months in the delayed rechallenge group. In this large cohort study of patients with R/M HNSCC receiving ICI-based therapy, survival estimates closely mirrored clinical trial results, both in frontline and later-line settings. Discontinuation of ICI in long-term responders at 1 or 2 years may be a reasonable strategy that does not appear to compromise survival. ICI rechallenge was associated with clinical benefit in a subset of patients.

Proportional Hazards Violations in Phase III Cancer Clinical Trials: A Potential Source of Trial Misinterpretation.

Survival analyses of novel agents with long-term responders often exhibit differential hazard rates over time. Such proportional hazards violations (PHV) may reduce the power of the log-rank test and lead to misinterpretation of trial results. We aimed to characterize the incidence and study attributes associated with PHVs in phase III oncology trials and assess the utility of restricted mean survival time and maximum combination test as additional analyses. Clinicaltrials.gov and PubMed were searched to identify two-arm, randomized, phase III superiority-design cancer trials with time-to-event primary endpoints and published results through 2020. Patient-level data were reconstructed from published Kaplan-Meier curves. PHVs were assessed using Schoenfeld residuals. Three hundred fifty-seven Kaplan-Meier comparisons across 341 trials were analyzed, encompassing 292,831 enrolled patients. PHVs were identified in 85/357 [23.8%; 95% confidence interval (CI), 19.7%, 28.5%] comparisons. In multivariable analysis, non-overall survival endpoints [OR, 2.16 (95% CI, 1.21, 3.87); P = 0.009] were associated with higher odds of PHVs, and immunotherapy comparisons [OR 1.94 (95% CI, 0.98, 3.86); P = 0.058] were weakly suggestive of higher odds of PHVs. Few trials with PHVs (25/85, 29.4%) prespecified a statistical plan to account for PHVs. Fourteen trials with PHVs exhibited discordant statistical signals with restricted mean survival time or maximum combination test, of which 10 (71%) reported negative results. PHVs are common across therapy types, and attempts to account for PHVs in statistical design are lacking despite the potential for results exhibiting nonproportional hazards to be misinterpreted.

Developing a Machine-Learning Prediction Model for Infliximab Response in Crohn's Disease: Integrating Clinical Characteristics and Longitudinal Laboratory Trends.

Achieving long-term clinical remission in Crohn's disease (CD) with antitumor necrosis factor α (anti-TNF-α) agents remains challenging. This study aims to establish a prediction model based on patients' clinical characteristics using a machine-learning approach to predict the long-term efficacy of infliximab (IFX). Three cohorts comprising 746 patients with CD were included from 3 inflammatory bowel disease (IBD) centers between June 2013 and January 2022. Clinical records were collected from baseline, 14-, 30-, and 52-week post-IFX treatment. Three machine-learning approaches were employed to develop predictive models based on 23 baseline predictors. The SHapley Additive exPlanations (SHAP) algorithm was used to dissect underlying predictors, and latent class mixed model (LCMM) was applied for trajectory analysis of the longitudinal change of blood routine tests along with long-term IFX therapy. The XGBoost model exhibited the best discrimination between long-term responders and nonresponders. In the internal training and testing set, the model achieved an AUC of 0.91 (95% CI, 0.86-0.95) and 0.71 (95% CI, 0.66-0.87), respectively. Moreover, it achieved a moderate predictive performance in the independent external cohort, with an AUC of 0.68 (95% CI, 0.59-0.77). The SHAP algorithm revealed disease-relevant laboratory measurements, notably hemoglobin (HB), white blood cells (WBC), erythrocyte sedimentation rate (ESR), albumin (ALB), and platelets (PLT), alongside age at diagnosis and the Montreal classification, as the most influential predictors. Furthermore, 2 distinct patient clusters based on dynamic laboratory tests were identified for monitoring the long-term remission. The established prediction model demonstrated remarkable discriminatory power in distinguishing long-term responders from nonresponders to IFX therapy. The identification of distinct patient clusters further emphasizes the need for tailored therapeutic approaches in CD management.

6 Durable response to immunotherapy-based regimens for IMDC favorable risk patients with metastatic clear cell renal cell carcinoma: a pooled analysis of four published randomized control phase 3 trials

Abstract Background An immune checkpoint inhibitor (ICI) backbone of either ICI doublet (ipilimumab-nivolumab [ipi-nivo]) or tyrosine kinase inhibitor (TKI) with ICI (such as axitinib-pembrolizumab [axi-pembro], cabozantinib-nivolumab [cabo-nivo], or lenvatinib-pembrolizumab [len-pembro]) is the current standard of care for previously untreated, metastatic clear cell renal cell carcinoma (mccRCC). The phase 3 trials that evaluated these four regimens were compared to sunitinib, with no direct head-to-head clinical trial data available. With at least 4-year follow up data available, we compared the long-term responders of the IMDC favorable risk patients enrolled in the four phase 3 trials (CheckMate 214, KEYNOTE-426, CheckMate 9ER, and CLEAR). Methods Pseudo individual patient data (IPD) was obtained from the Kaplan-Meier (K-M) curves using the graph digitizer software IPDfromKM R package to extract coordinates of points on the curves and applied the numerical algorithm to reconstruct survival results. The hazard ratios (HRs) of the favorable risk group for both progression-free survival (PFS) and overall survival (OS) comparing the experimental arms to sunitinib were extracted. Responses were measured at 24 (durable response [DR]) and 36 months (extreme durable response [EDR]) and long-term OS as OS ≥48 months. K-M method using the extracted IPD was used to estimate the survival rates at 24-month PFS, 36-month PFS, and 48-month OS. Then, we compared the survival rates at each time point using the generalized linear model for the survival rates at fixed time points obtained from the K-M method. Results Len-pembro was associated with the highest DR (57.2%) and EDR (44.5%), while ipi-nivo had the lowest DR (36.0%), and cabo-nivo had the lowest EDR (18.8%). There was no difference in 48 month-OS among regimens (p=0.11), ranging between 58.3% (cabo-nivo) and 70.6% (len-pembro). Comparing the sunitinib control arms among the four studies, a numerically higher PFS at 24 months (59%) and 36 months (40%) was observed in the CheckMate 214 trial compared to the ICI-TKI trials (25-35% and 15-20%, respectively). The 48-month OS for the sunitinib arms ranged from 55-70%, and no differences were observed among trials (p=0.55). Comparisons of survival rates for the immunotherapy arm on fixed time-points for IMDC favorable risk subset of patients Conclusions ICI-based regimens provided durable responses to a significant number of patients with favorable risk mccRCC. While TKI-ICI were associated with higher DR and EDR, no differences in OS at 48 months were observed compared to ipi-nivo or sunitinib for favorable risk disease. Longer follow-up is necessary to evaluate long-term outcomes given the favorable prognosis of these patients. We acknowledge the limitations and caveats of cross-trial comparisons.

Progression-Free Survival and Treatment-Free Interval in Head and Neck Cancer with Long-Term Response to Nivolumab: Timing of Active Discontinuation.

The optimal timing for actively discontinuing immune checkpoint inhibitor therapy in long-term responders with recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC) remains unresolved. We conducted a retrospective study of 246 patients with R/M HNSCC treated with nivolumab to determine the optimal timing to actively discontinue nivolumab therapy. We examined the point at which progression-free survival (PFS) plateaued in all cases. We compared the prognosis of 19 (7.7%) ongoing cases and 227 (92.3%) discontinued cases and analyzed treatment duration and treatment-free interval (TFI). The 6-year overall survival was 11.8% (median, 12.1), and the 6-year PFS was 15.3% (median, 3.0). The PFS curve remained stable for 3 years. The median duration of nivolumab treatment was 2.9 months (range 0.03-81.9): Ongoing group, 41.8 (5.6-81.9); Decision group, 36.8 (4.0-70.1); Toxicity group, 30.6 (2.8-64.8); and progressive disease group, 2.0 (0.03-42.9). TFI in the Decision group was 15.1 months (0.6-61.6) and 30.6 months (2.8-64.8) in the Toxicity group. Long-term responses in R/M HNSCC patients treated with nivolumab are rare but gradually increasing. For this patient group, our best estimate of the optimal time to end treatment is 3 years, as the PFS in this study reached a plateau at that timepoint.

Long-term responders to nivolumab in previously treated advanced renal cell carcinoma: a sub-analysis of meet-URO15 study

BackgroundAlthough nivolumab prolongs overall survival (OS) in pretreated patients with metastatic renal cell carcinoma (mRCC), underlining clinical and biological features of long-term responses are still to be determined. This study aims to investigate clinical and pathological characteristics of mRCC patients who achieved long-term responses during nivolumab treatment.Materials and methodsA retrospective analysis was performed on mRCC patients receiving nivolumab as second or further therapy line between May 2016 and January 2019 in 34 Italian Oncology Centres. Outcome assessments and logistic regression were performed to evaluate factors influencing long-term responses.ResultsA total of 571 patients with a median age of 61 years (range 17–85) were included in the analysis. With a median follow-up of 22.1 (1.0–89.0) months, 23.1% of patients were 2-year progression-free on treatment with nivolumab, hence they were categorized as long-term responders. Baseline characteristics, including age, gender, and histology, were similar between long- and short-term responders. Karnofsky Performance Status ≥ 80% was significantly associated with long-term response (p = 0.02), while bone metastases (p = 0.03), International mRCC Database Consortium intermediate-poor risk (p < 0.01) and Neutrophil-to-Lymphocyte Ratio ≥ 3.2 (p = 0.02) were associate with short-term responses. Long-term responders exhibited a median progression-free survival of 55.0 months versus 4.0 months of the short-term responders. The median OS was not reached in long-term responders while it was 17.0 months for short*term responders.ConclusionThis retrospective analysis sheds light on factors associated with long-term response to nivolumab in mRCC. Understanding these clinical features will be essential for selecting patients who may mostly benefit from immunotherapy.

On the Way to Curing Advanced-Stage Mycosis Fungoides/Sézary Syndrome

Advanced-stage mycosis fungoides (MF) and Sézary syndrome (SS) have poor prognosis with median survivals of less than 5 years. Although a variety of treatments are approved for MF/SS patients, durable complete remissions (CR) are rare. Advanced-stage MF or SS patients who achieved CR and maintained in CR or stage IA for more than 10 years were identified by a retrospective search of the principal investigator's database. Of 2266 patients diagnosed with MF or SS, 23 patients with advanced-stage MF/SS (6 IIB, 1 IIIB, 5 IVA1, 3 IVA2, 8 IVB) who achieved CR and maintained in CR or stage IA for ≥ 10 years were identified. As final/curative treatment, 11 patients underwent allogeneic stem cell transplantation (SCT). Most patients presented at young age, underwent SCT with reduced intensity conditioning regimen, had matched related donors, and controllable post-transplant graft versus host disease. Eleven patients were treated with TSEB as part of combined modality protocol in 2 patients and debulking therapy before allogeneic SCT in 9 patients. Five stage IIB patients achieved CR with radiotherapy. Four patients with blood involvement were treated with extracorporeal photopheresis (ECP) in combination with long-term antibiotics and immunomodulatory agents. Long-term antibiotics were given to 14 patients. TSEB followed by allogeneic SCT, radiotherapy, ECP plus long-term antibiotics and immunomodulatory agents were the most common curative/final treatments found in our patients. We are reporting the details of our long-term complete responders' treatment course in the hopes of obtaining more cure responses in the future.

Prognostic factors and long-term survivors in EGFR-mutated lung cancer: A multi-institutional retrospective analysis.

e20594 Background: Evolution of tyrosine kinase inhibitors (TKIs) shapes the treatment paradigm of EGFR-mutated lung cancer, but resistance eventually develops. It is important to dissect the prognostic factors and to know the differences between long-term responders (LTR) and non-responders (NR). Methods: Electronic medical records were retrieved from Chang-Gung Medical Foundation from 2011 to 2020. Kaplan-Meier method was used to estimate survival, such as progression-free survival (PFS), and overall survival (OS). Multivariate Cox proportional hazard models was adopted to estimate adjusted hazard ratios and 95% confidence intervals. P &lt; 0.05 was set to be statistical significance. Results: Totally, there are 3,551 patients receiving frontline TKIs, of which 825 (23.2%) are LTR with OS &gt; 36 months, and 1,036 (29.2%) are NR with OS &lt; 12 months. Besides, there are 1,200 (33.8%) LTRs with PFS &gt; 18 months and 882 (24.8%) NR with PFS &lt; 6 months. LTR tend to be younger, female, non-smoker, clinical stage 3b, no baseline brain metastasis, exon 19 deletions subtype, subsequent T790M development, bevacizumab usage, and osimertinib exposure (p all &lt; 0.05). The median PFS of all enrolled patients is 12.3 months and median OS is 22.3 months. By multivariate analysis, age older than 65 years (Hazard ratio, [HR]:1.25 [1.15-1.36]), male (HR: 1.24 [1.13-1.36]), clinical stage 4 (2.19 [1.78-2.69]), baseline brain metastasis (1.25 [1.12-1.37]) are poor prognostic factors (p &lt; 0.05). Also, T790M is not only predictive to osimertinib but also prognostic factor to OS (p &lt; 0.05), and patients who developed subsequent T790M tend to have better PFS (18.1 v.s. 11.8 months). In patients without detected T790M along their disease course, exposure to osimertinib is related to better OS (33.1 v.s. 18.3 month, log-rank p &lt; 0.05). Conclusions: LTR and NR are of distinctive characteristics, and T790M is prognostic and predictive to osimertinib. Further study is warranted for choosing the optimal treatment by clinical factors and T790M status.

Efficacy of imetelstat on red blood cell (RBC)-transfusion independence (TI) in the absence of platelet transfusions or myeloid growth factors in IMerge.

6566 Background: In the IMerge trial (NCT02598661) of RBC transfusion-dependent (TD) patients (pts) with lower-risk myelodysplastic syndromes (LR-MDS) relapsed/refractory to or ineligible for erythropoiesis stimulating agents, imetelstat showed significant efficacy vs placebo (PBO) for 8-wk, 24-wk, and 1-y TI endpoints, with neutropenia and thrombocytopenia as the most common adverse events (Platzbecker. Lancet 2024). Supportive care was given to all pts as needed, per investigator discretion. Here we report RBC-TI rates in the absence of platelet transfusions or myeloid growth factor use. Separately, RBC-TI with mean central hemoglobin (Hb) rise of ≥1.5 g/d was assessed in all pts. Methods: Pts were randomized 2:1 to receive imetelstat (n=118) 7.5 mg/kg or PBO (n=60) Q4W IV until disease progression. Primary endpoint was 8-wk RBC-TI; 24-wk RBC-TI was a key secondary endpoint. Primary analysis cutoff was Oct 2022, with Oct 2023 cutoff for 1-y RBC-TI analyses. Results: Overall, 21/118 (18%) pts in the imetelstat group and 1/60 (2%) pts in the PBO group needed platelet transfusions; 41/118 (35%) and 2/60 (3%) pts received myeloid growth factors, respectively. Significantly higher percentages of pts achieved 8-wk, 24-wk, and 1-y RBC-TI with imetelstat vs PBO in the absence of either platelet transfusions or growth factor support (Table). In a separate analysis, 8-wk, 24-wk, and 1-y RBC-TI and concurrent Hb rise of ≥1.5 g/dL with imetelstat vs PBO occurred in 28% vs 2%, 23% vs 0%, and 17% vs 0% of pts, respectively (Table). Among responders, imetelstat increased median central Hb levels compared with PBO: 3.6 g/dL vs 0.8 g/dL for 8-wk, 4.2 g/dL vs 1.1 g/dL for 24-wk, and 5.2 g/dL vs 1.7 g/dL for 1-y RBC-TI. Conclusions: Results from this subanalysis confirm that pts who achieve RBC-TI with imetelstat do so without developing severe neutropenia and thrombocytopenia (functionally defined as needing myeloid growth factors or platelet transfusions, respectively), therefore not negating the clinical benefit of the drug. Imetelstat also led to significant rise in Hb levels in RBC-TI responders, particularly long-term responders. These data further support the efficacy of imetelstat in TD pts with LR-MDS. Clinical trial information: NCT02598661 . [Table: see text]