Progression-free Survival Research Articles

Entinostat in combination with nivolumab in metastatic pancreatic ductal adenocarcinoma: a phase 2 clinical trial.

Pancreatic ductal adenocarcinoma (PDA) is characterized by low cytotoxic lymphocytes, abundant immune-suppressive cells, and resistance to immune checkpoint inhibitors (ICI). Preclinical PDA models showed the HDAC inhibitor entinostat reduced myeloid cell immunosuppression, sensitizing tumors to ICI therapy. This phase II study combined entinostat with nivolumab (PD1 inhibitor) in patients with advanced PDA (NCT03250273). Patients received entinostat 5 mg orally once weekly for 14-day lead-in, followed by entinostat and nivolumab. The primary endpoint was the objective response rate (ORR) by RECIST v1.1. Secondary endpoints included safety, duration of response, progression free-survival and overall survival. Between November 2017 and November 2020, 27 evaluable patients were enrolled. Three showed partial responses (11% ORR, 95% CI, 2.4%-29.2%) with a median response duration of 10.2 months. Median progression-free survival (PFS) and overall survival (OS) were, respectively, 1.89 (95% CI, 1.381-2.301) and 2.729 (95% CI, 1.841-5.622) months. Grade ≥3 treatment-related adverse events occurred in 19 patients (63%), including decreased lymphocyte count, anemia, hypoalbuminemia, and hyponatremia. As exploratory analysis, peripheral and tumor immune profiles changes were assessed using CyTOF, mIHC, and RNA-seq. Entinostat increased dendritic cell activation and maturation. Gene expression analysis revealed an enrichment in inflammatory response pathways with combination treatment. Although the primary endpoint was not met, entinostat and nivolumab showed durable responses in a small subset of PDA patients. Myeloid cell immunomodulation supported the preclinical hypothesis, providing a basis for future combinatorial therapies to enhance clinical benefits in PDA.

Efficacy and safety of regorafenib for the treatment of metastatic colorectal cancer in routine clinical practice: results from a Spanish hospital

IntroductionRegorafenib is indicated as treatment in third-line and beyond in patients with metastatic colorectal cancer.Methods This is a retrospective study of a cohort of patients with mCRC treated with regorafenib in Hospital Universitario Ramón y Cajal, in Madrid, Spain.ResultsWith the aim to assess the efficacy and safety of regorafenib, 91 patients treated between 2013 and 2023 were included. Only 1.1% of patients achieved disease control. Median progression free survival was 2.40 months and median overall survival was 4.76 months. The most frequent adverse events were fatigue and hand-foot skin reaction (59.34% and 28.57%, respectively).DiscussionOur results confirm the safety of regorafenib as treatment of mCRC in real clinical practice. Although our population is less pretreated than in the CORRECT trial, our disease control rate was inferior. This difference may be due to a worse baseline status and a high percentage of hepatic disease showed in our patients.

Hsa_circRNA_000166 accelerates breast cancer progression via the regulation of the miR-326/ELK1 and miR-330-5p/ELK1 axes

Purposes To probe the expression, clinical significance, roles, and molecular mechanisms of circRNA_000166 in breast cancer (BC). Methods Clinical tissue samples were gathered from 84 BC patients who underwent surgery at the Affiliated Hospital of Chengde Medical College. Clinical data were obtained from medical records and postoperative follow-up. Expression levels of circRNA_000166, miR-326, miR-330-5p, and ELK1 mRNA in BC tissues and cells were measured by qRT-PCR, and ELK1 protein levels were assessed by WB. Pearson’s correlation analysis evaluated the interrelationships between these RNAs in clinical samples. Luciferase reporter assays verified the interactions between miR-326/miR-330-5p and circRNA_000166, as well as between miR-326/miR-330-5p and ELK1. Cell proliferation, migration, and apoptosis were examined using CCK-8, colony formation, transwell, and flow cytometry assays, respectively. Results CircRNA_000166 was highly expressed in BC tissues and inversely correlated with miR-326/miR-330-5p levels but positively with ELK1 mRNA levels. ELK1 mRNA also inversely associated with miR-326/miR-330-5p levels in BC tissues. Importantly, our findings demonstrated that circRNA_000166 targets miR-326 and miR-330-5p, while ELK1 is the target of miR-326 and miR-330-5p in BC cells. CircRNA_000166 levels positively correlated with tumour size, TNM stage, histological grade, and lymph node metastasis, and negatively associated with postoperative progression-free survival (PFS) and overall survival (OS) in BC patients. CircRNA_000166 was also highly expressed in BC cells, and knockdown of circRNA_000166 reduced proliferation and migration, and increased apoptosis via miR-326/ELK1 and miR-330-5p/ELK1 pathways in vitro. Conclusion CircRNA_000166 enhances BC progression through miR-326/ELK1 and miR-330-5p/ELK1 pathways and shows potential as a biomarker for BC diagnosis and treatment.

EGFR-TKIs or EGFR-TKIs combination treatments for untreated advanced EGFR-mutated NSCLC: a network meta-analysis.

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) and EGFR-TKI combination treatments have become the standard first-line treatments for EGFR-mutated non-small cell lung cancer (NSCLC) patients. However, the best option has yet to be determined. This study compares the efficacy and safety of various first-line EGFR-TKI monotherapies and combination treatments for advanced EGFR-mutated NSCLC. We searched PubMed, Embase, the Cochrane Central Register of Controlled Clinical Trials databases, and several international conferences to identify randomized controlled trials reporting on first-line EGFR-TKI treatments for patients with advanced EGFR-mutated NSCLC. The study quality was assessed using the revised tool for risk of bias in randomized trials. The efficacy and safety outcomes of the included treatments were compared by network meta-analysis based on a frequentist approach. We identified 26 trials (8,359 patients) investigating 14 treatment groups, including first, second, and third-generation EGFR-TKIs and their combination treatments. Osimertinib plus chemotherapy and lazertinib plus amivantamab showed the highest efficacy in improving progression-free survival. New third-generation EGFR-TKIs demonstrated comparable efficacy to osimertinib alone but did not surpass it. Subgroup analyses revealed slight variation in treatment efficacy based on mutation types and patient demographics. Combination treatments were associated with a higher incidence of adverse events. These results reveal that osimertinib plus chemotherapy and lazertinib plus amivantamab are superior first-line options for patients with advanced EGFR-mutated NSCLC. However, these combinations are associated with higher adverse event rates.

Advancements in breast cancer management: a comprehensive review of ribociclib combined with endocrine therapy

Background: In this review, the complicated landscape of breast cancer management is explored with a focus on the promising synergies between ribociclib and endocrine therapy. Ribociclib mainly acts as a cyclin-dependent kinase 4/6 (CDK4/6) inhibitor, which disrupts cell cycle progression necessary for tumor growth. This, in combination with endocrine therapy, aims to produce hormone receptor-positive breast cancers, which is a very relevant subtype with challenging therapeutics. Methods: A comprehensive review was conducted using multiple databases, PubMed, Embase, Scopus, Cochrane Library, and Web of Science, covering the period from January 1990 to May 2024. Results: Pharmacokinetic studies underscore the efficacy and tolerability of ribociclib, thus providing vital information for dose adjustments, particularly among patients with renal and hepatic impairments. Ribociclib’s value in extending progression-free survival and improving overall survival has been shown by clinical trials such as the MONALEESA series. Quality of life considerations and patient-reported outcomes from these trials indicate that ribociclib has a broader effect on the well-being of the patients. However, despite the success experienced by this drug in clinical practice, it still has some side effects, including hematologic toxicity, hepatotoxicity, and thromboembolism associated with it. Ribociclib resistance mechanisms are multifaceted mixtures comprising genetic variations or mutations, compensatory signaling pathways, and epigenomic changes. While overcoming resistance remains challenging, ongoing research seeks to reconcile. Conclusion: Ribociclib combined with endocrine therapy represents a significant advancement in breast cancer treatment, albeit with challenges that necessitate ongoing research and holistic patient care approaches.

Ten-Year Outcome of a Randomized Trial: Cytoreduction and HIPEC with Mitomycin C Versus Oxaliplatin for Appendiceal Neoplasm with Peritoneal Dissemination.

Appendiceal cancer is a rare disease that has proven difficult to study in prospectively. Our initial reportof this trial showed minor hematologic toxicity with both mitomycin C and oxaliplatin and similar 3-year survival. We now report an update of the first prospective randomized trial for appendiceal cancer with 10-year follow up. Patients with mucinous appendiceal neoplasms and evidence of peritoneal dissemination were enrolled in the Multicenter Randomized Trial to evaluating HIPEC for 120min with oxaliplatin (200mg/M2) or mitomycin C (40mg). Overall survival and disease-free survival were calculated at 10 years and compared between the groups. A total of 121 patients were included in the study. The patients were 57% female, with a mean age of 55.3 years (range 22-82 years). The disease was low grade in 71% and high grade in 29%. The average peritoneal cancer index (PCI) score was 18 (SD 10) in the mitomycin C group and 17.9 (SD 9.4) in the oxaliplatin group (p = 0.94). The 10-year survival rate was 56.2% (SE 7.2) with mitomycin C and 47.5% (SE 8.4) with oxaliplatin, p = 0.83. The 10-year progression-free survival rate in the mitomycin C group was 45.2% (SE 8.4) compared with 50.4% (SE 6.7) in the oxaliplatin group, p = 0.95. Median survival was 9.1 years after HIPEC with oxaliplatin, and median not reached for the mitomycin C group (> 5.6years). Oxaliplatin and mitomycin C have similar long-term efficacy for hyperthermic intraperitoneal chemotherapy (HIPEC) in patients with appendiceal neoplasms and peritoneal dissemination. Long-term survival is experienced by most patients after cytoreduction surgery (CRS) and HIPEC for appendiceal neoplasms.

A phase 4, multicenter, global clinical study to evaluate discontinuation and rechallenge of pexidartinib in patients with tenosynovial giant cell tumor previously treated with pexidartinib.

Pexidartinib is effective in patients with tenosynovial giant cell tumor (TGCT) for whom surgery is not feasible. Durability of response after discontinuation of pexidartinib and the safety and efficacy of restarting pexidartinib have not been previously recorded. This phase 4 study was designed to mimic the real-world experience with pexidartinib to evaluate the effects of discontinuation of and retreatment with pexidartinib in patients with TGCT who previously benefited from the drug. This was a global, multicenter, phase 4 study that enrolled patients with TGCT who were experiencing clinical benefit from pexidartinib in one of four prior phase 1 or phase 3 studies investigating pexidartinib in the disease. Patients could choose to continue pexidartinib at the same dose (the treatment-continuation cohort) or discontinue treatment with the option to restart pexidartinib (the treatment-free/retreatment cohort). Tumor progression determined by Response Evaluation Criteriain Solid Tumors (RECIST) version 1.1, patient-reported outcomes (the Patient-Reported Outcomes Measurement Information System-Physical Function [PROMIS-PF] questionnaire and the EuroQol 5-dimension, 5-level [EQ-5D-5L] visual analog scale), and safety were assessed every 3 months. The primary end point was the proportion of patients in the treatment-free/retreatment cohort who remained treatment-free at month 12 and 24; this did not depend on disease progression. Thirty-two patients were enrolled: 21 chose to enter the treatment-continuation cohort, and 11 entered the treatment-free/retreatment cohort. During the treatment-free period, six of 11 (54.5%) patients in the treatment-free/retreatment cohort had progressive disease (PD) according to RECIST, version 1.1, whereas no patient in the treatment-continuation cohort had disease progression. Over the 24-month study, three of 11 (27.3%) patients in the treatment-free/retreatment cohort restarted treatment because of RECIST version 1.1 PD, symptomatic progression, or both (n=1 each). The probability of remaining treatment-free in the treatment-free/retreatment cohort was 73% (95% confidence interval, 37%-90%). In the treatment-free/retreatment cohort, the median progression-free survival of the treatment-free period was 22.8 months (95% confidence interval, 1.6 months to not estimable). By 6 months of retreatment, all retreated patients achieved new disease stabilization with no new safety concerns; two patients had clinically significant improvements in PROMIS-PF and EQ-5D-5L visual analog scale scores. The mean PROMIS-PF and EQ-5D-5L scores remained stable throughout the study. There was no hepatotoxicity and no new safety signal in either cohort. In this small phase 4 study designed to evaluate outcomes in patients who stopped and restarted pexidartinib, 54.5% of patients who discontinued pexidartinib showed PD, with a median progression-free survival of 22.8 months. Each of the three patients who restarted pexidartinib stopped progressing, and some reported a new gain in physical function. No PD was detected in patients who remained on treatment, and the safety profile did not indicate long-term hepatotoxicity or any new safety concerns. Pexidartinib is a medication for people with tenosynovial giant cell tumor (TGCT) for whom surgery is not recommended. This study examined what happens when patients stop taking pexidartinib (after it has helped them) to see whether it is safe and effective to restart if needed. Thirty-two patients were followed for 2 years: 21 chose to continue pexidartinib and did not experience disease progression, while 11 chose to stop pexidartinib; 54.5% of them had disease progression within 2 years. Three patients who stopped pexidartinib restarted treatment after their tumor size increased or their symptoms worsened. Restarting pexidartinib was safe and effective in these patients.

RADT-04. SEQUENCING OF CHECKPOINT INHIBITORS AND RADIOTHERAPY IN MELANOMA BRAIN METASTASES: A META-ANALYSIS OF COMPARATIVE STUDIES

Abstract OBJECTIVE Melanoma brain metastases significantly worsen prognosis, with incidence rates as high as 50%. While both immunotherapy and radiotherapy improve survival, the optimal sequencing remains undetermined. This meta-analysis aims to define the most effective treatment sequence for improving progression-free survival (PFS) and overall survival (OS). METHODS A review of the medical literature was conducted using online databases. Inclusion criteria consisted of English language, diagnosis of melanoma brain metastases, comparative studies of immune checkpoint inhibitors given before or after radiotherapy, and those that reported overall (OS) and progression-free (PFS) survival. Studies that reported mixed data that included concurrent immune checkpoint inhibitors with radiotherapy were excluded. A meta-analysis using the fixed effects and random effects models was conducted. RESULTS Our analysis included six retrospective studies encompassing 213 patients, with a median age of 62 years and follow-up of 22 months. The results indicate a clear disadvantage in PFS when immunotherapy precedes radiotherapy (HR=1.77; 95% CI 1.21-2.60; p=0.003; I2=13.5%). Similarly, initiating treatment with immune checkpoint inhibitors followed by radiotherapy showed a trend towards poorer OS compared to the reverse sequence, although this finding was of borderline significance (HR=1.39; 95%CI 0.97-1.99; p=0.07; I2=0%). CONCLUSIONS This meta-analysis, the first and largest to date, provides compelling evidence that initiating treatment with radiotherapy followed by immune checkpoint inhibitors significantly improves PFS with a trend for a better OS in patients with melanoma brain metastases. These findings suggest that radiotherapy should precede immunotherapy to optimize clinical outcomes in this patient population. Further research, particularly prospective studies, is necessary to confirm these results.

NCOG-21. ADJUVANT RADIATION THERAPY IN ATYPICAL MENINGIOMA TREATMENT DOES NOT IMPROVE PROGRESSION FREE SURVIVAL OR OVERALL SURVIVAL: A RETROSPECTIVE COHORT STUDY

Abstract Treatment of atypical meningiomas (AMs) presents a challenge due to their aggressive nature and tendency to recur. While there is clear evidence for the role of surgical resection of AMs, the use of adjuvant radiation therapy (ART) is a topic of ongoing debate. The aim of this study is to explore the impact of ART following surgical resection of AMs. The primary outcomes of interest are progression free survival (PFS) and overall survival (OS). Records were reviewed for all patients treated for Ams at our institution between January 1, 2014 and January 1, 2024. Patients were grouped into two cohorts, those who were initially treated with surgical resection only and those who also received adjuvant RT. PFS and OS were compared between the two groups using Kaplan Meier curves and Log Rank test. Additionally, multivariable cox proportional hazard models were used to adjust for age, MIB, and resection Simpson grading. There were 76 patients who were initially treated with surgery only and 23 patients who had surgery and ART. No significant difference in PFS or OS was observed between the groups (p=0.3522 and p=0.3636, respectively); including after adjusting for age, MIB, and Simpson grading (HR= 1.55 [0.64-3.76], p= 0.330; and HR = 0.95 [0.31-2.93] p= 0.934, respectively). On multivariate analysis, MIB >10 was associated with a significant difference in PFS (HR=2.76 [1.15-6.59], p=0.023). With ART, PFS was 91% at 12 and 60% at 36 months (versus 89% and 57%, respectively, with surgery only). OS was 95% at 12 and 88% at 36 months (versus 91% and 85%, respectively, with surgery only). In this series, ART was not observed to significantly improve PFS or OS compared to surgery alone. Larger series are needed to determine if there is a subset of patients who benefit from ART.

PATH-26. MIDLINE INVOLVEMENT IS ASSOCIATED WITH ABERRANT RB1 SIGNALING IN PATIENTS WITH GRADE 4 IDH-MUTANT ASTROCYTOMA

Abstract BACKGROUND The prognostic factors impacting the survival of grade 4 IDH-mutant astrocytoma treated with standard radiation/temozolomide are not well-described. METHODS A retrospective cohort was generated of all patients diagnosed at Mayo Clinic with grade 4 IDH-mutant astrocytoma (2021 WHO Classification) on initial diagnosis between 2002-2023, and who received standard radiation/temozolomide. The impact of patient, tumor and molecular variables on overall survival (OS) and progression-free survival (PFS) was evaluated using survival analyses and Cox regression models. RESULTS Fifty-eight patients were identified. The median age was 36 years, 64% were male and 93% were white. The median follow up was 3.3 years. The median OS and PFS were 6.9 years and 2.4 years, respectively. CDKN2A/B homozygous deletion significantly reduced both OS (2.5 years vs NR, HR=3.9, p=0.0168) and PFS (1.4 vs 4.5 years, HR=4.2, p=0.0005). Midline involvement (brainstem, basal ganglia, thalamus, cerebellum or corpus callosum) also significantly reduced both OS (2.4 vs 12.8 years, HR=7.0, p=0.0014) and PFS (1.4 vs 4.5 years, HR=4.8, p=0.0002). MGMT promoter hypermethylation showed a trend toward significance for PFS (p=0.082) but did not impact OS. Age, sex, tumor size, ATRX immunohistochemistry and tumor-treating field therapy did not impact survival outcomes. Multivariable analyses revealed that PFS remained significantly impacted by both CDKN2A/B homozygous deletion (HR=3.5, p=0.0051) and midline involvement (HR=3.1, p=0.0125). A significant association between CDKN2A/B homozygous deletion and midline involvement was unexpectedly observed (53% if midline, 24% if non-midline; χ2=4.3, p=0.037). Exploratory analyses revealed that 15/15 (100%) of patients with midline involvement demonstrated aberration in RB1 signaling (CDKN2A/B homozygous deletion, n=8; CDKN2A/B hemizygous deletion or loss of heterozygosity, n=6; CDK4 amplification, n=1). CONCLUSION CDKN2A/B homozygous deletion and midline involvement independently impact PFS in patients with grade 4 IDH-mutant astrocytoma treated with standard radiation/temozolomide. Furthermore, midline involvement may be associated with aberrant RB1 signaling.

NCOG-35. IDENTIFYING PROGNOSTIC FACTORS IN PEDIATRIC DIFFUSE MIDLINE GLIOMAS, H3 K27-ALTERED

Abstract INTRODUCTION Diffuse midline gliomas, H3 K27-altered (DMG) are rare, grade 4 tumors localized to the diencephalon, brainstem, and cervical spine. DMGs, characterized by a K27M missense mutation in histone H3, often cannot be safely resected and predominantly present with poor outcomes in children. Few prognostic factors for DMGs have been identified and/or need to be further elucidated, including adolescent age of onset, re-irradiation status, and tumor molecular profile (i.e., PIK3CA mutation). Herein, we describe the clinical outcomes of DMG patients at our institution. METHODS Pediatric patients (<18 y/o) between 2015 and 2023 with biopsy-proven DMG were reviewed. Demographic, treatment, and tumor characteristics (histologic and molecular) were recorded. Adolescent-onset DMGs were defined as patients ≥10 y/o at diagnosis and early-onset DMGs were defined as patients <10 y/o. Progression free survival (PFS) and overall survival (OS) were calculated according to the Kaplan Meier-method. Multivariate regression analyses were performed. RESULTS Twenty-one patients were included (median age=9 y/o). Early-onset DMGs (n=13) progressed significantly earlier and experienced significantly greater mortality than adolescent-onset DMGs (n=8); PFS and OS at 12 months was 7.7% and 23% for early-onset DMGs and 50% and 87.5% for adolescent-onset DMGs (PFS: p<0.01, OS: p<0.02). Patients that received re-irradiation for progressive disease (n=9, mean=84Gy) had an OS of 75% at 12 months, which was significantly greater than an OS of 23% at 12 months (p<0.05) for patients that received no re-irradiation (n=12, mean=53Gy). PIK3CA mutation status was identified as an independent predictor of survival, with PIK3CA-mutant DMGs (n=7) having a median survival of 4.1 months versus 9.7 months for PIK3CA-WT DMGs. CONCLUSION We describe a pediatric cohort that presents several possible prognostic factors of survival in DMGs. Our findings on adolescent age of onset, if further corroborated, has the potential to inform the design and enrollment of DMG clinical trials.

EXTH-59. ESTABLISHING GAUSSIA LUCIFERASE REPORTER AS A BIOMARKER FOR ESTIMATING THERAPEUTIC RESPONSE AND PROGRESSION-FREE SURVIVAL IN PATIENT-DERIVED XENOGRAFT MODELS OF GLIOBLASTOMA

Abstract Serial monitoring of tumor burden in patient-derived xenograft (PDX) models used for testing new cancer drugs via MRI and other imaging techniques can be costly. We theorized that transducing the Gaussia luciferase (GLuc) reporter gene into glioma PDX models (GliomaPDOX) allows for GLuc to be used as a biomarker for tumor burden. This current study investigates whether changes in the rate of GLuc secretion over time (i.e., “growth rate” changes) can predict survival in GliomaPDOX. Optimal cutoff values to define disease progression via GLuc measurements were established resulting in a strong association between progression-free survival (PFS) and overall survival (OS). The pLenti-CMV-sGluc-T2A-EGFP plasmid was packaged into a second-generation lentiviral system via HEK293FT cells, and the resulting virus transduced into directly-isolated glioma patient cells to establish the MGMT-Unmethylated and MGMT-Methylated GliomaPDOX. MGMT-Unmethylated GliomaPDOX were treated with placebo or Temozolomide (TMZ) until endpoint. MGMT-Methylated GliomaPDOX were treated with placebo or TMZ for three weeks or TMZ for six weeks until endpoint. Treatment response was monitored through GLuc measurements obtained via tail blood collection. The optimal cutoff for time to progression was a 30% increase in GLuc, which yielded a significant positive association between PFS and OS across all models and treatments (R2 = 0.8177, p<0.0001). Compared to the MGMT-Methylated placebo and MGMT-Unmethylated groups, the MGMT-Methylated treatment groups exhibited substantial changes in GLuc growth rates and significantly longer PFS and OS (p<0.0001). More specifically, the six-week MGMT-Methylated TMZ-treated group demonstrated a significant difference in GLuc growth rates and a considerable PFS (p<0.0038) and OS increase (p<0.0049) when compared to the three-week MGMT-Methylated TMZ-treated group. Therefore, GLuc measurement is a valuable biomarker for PDX tumor burden and can be used to estimate treatment response and PFS.

NIMG-24. PRECISION GLIOBLASTOMA MANAGEMENT USING MET AND FMISO PET SCANS

Abstract OBJECTIVE Positron Emission Tomography (PET) may be useful in diagnosing glioblastoma, determining resection areas, and evaluating therapeutic efficacy. This study evaluated the usefulness of PET scans using 11C-Methionine (MET) to assess amino acid metabolism and 18F-Fluoromisonidazole (FMISO) to assess hypoxic regions in glioblastoma treatment. METHODS Thirty glioblastoma patients who underwent MET and FMISO PET studies from July 2013 to March 2024 were included. Patients underwent the Stupp regimen post-tumor resection and were treated with temozolomide (TMZ) and bevacizumab (Bev) upon recurrence. PET scans were performed before and after two courses of Bev treatment. Changes in tumor to normal ratio (TNR) for MET, tumor to blood ratio (TBR) for FMISO, and metabolic tumor volume (MTV) for both MET and FMISO were evaluated. Progression-free survival (PFS) and overall survival (OS) were compared based on the rate of change in MTV for MET and FMISO. RESULTS The residual volumes (contrast-enhanced MRI, MET, and FMISO) with a MET removal rate of >90% were 0.08 ml, 0.1 ml, and 0.08 ml, respectively. For FMISO removal rates of >90%, residual volumes were 0.36 ml, 1.54 ml, and 0.05 ml, respectively. Groups with a decreased rate of change in MET MTV had significantly better outcomes: PFS (months) 10.7 vs. 2.8 (p=0.19) and OS (months) 18.6 vs. 4.9 (p=0.09). In the FMISO groups, decreased TBR change rates correlated with better outcomes: PFS (months) 16.6 vs. 2.5 (p<0.01) and OS (months) 22.8 vs. 4.9 (p<0.01). MTV change rates also showed significant differences in outcomes: PFS (months) 10.5 vs. 3.7 (p=0.76) and OS (months) 14.9 vs. 7.0 (p=0.87). CONCLUSION Higher MET removal rates correlate with fewer contrast-enhanced MRI and FMISO accumulation areas, suggesting MET as a reliable tumor removal indicator. Both MET and FMISO PET scans are valuable in determining glioblastoma treatment response.

CTNI-53. A GLOBAL, RANDOMIZED, DOUBLE-BLINDED, PHASE 3 STUDY OF VORASIDENIB VERSUS PLACEBO IN PATIENTS WITH ADULT-TYPE DIFFUSE GLIOMA WITH AN IDH1/2 MUTATION (INDIGO): UPDATED EFFICACY RESULTS

Abstract INTRODUCTION The Phase 3 INDIGO study (NCT04164901) evaluated vorasidenib, an oral, brain-penetrant, dual inhibitor of mutated isocitrate dehydrogenase 1/2 (mIDH1/2), in patients with mIDH1/2 diffuse glioma. The primary endpoint of progression-free survival (PFS) per blinded independent review committee (BIRC), and key secondary endpoint of time to next intervention (TTNI), were met in the positive, preplanned second interim analysis (IA2). The study was unblinded in March 2023 following independent data monitoring committee recommendation. Here, we present results after an additional 6 months of follow-up between the database lock for IA2 (September 6, 2022) and study unblinding (March 7, 2023). METHODS Patients with residual/recurrent grade 2 mIDH1/2 oligodendroglioma or astrocytoma were enrolled (≥12 years; Karnofsky Performance Status ≥80; measurable non-enhancing disease; surgery as only prior treatment; no immediate need of chemoradiotherapy). Patients were randomized 1:1 to vorasidenib 40 mg or placebo daily in 28-day cycles. RESULTS Overall, 331 patients were randomized (median age: 40.0 years; oligodendroglioma: 172; astrocytoma: 159). As of March 7, 2023, 123/168 (73%) patients remained on vorasidenib and 72/163 (44%) remained on placebo. PFS per BIRC remained in favor of vorasidenib (HR, 0.35; 95% CI, 0.25–0.49), and was consistent with PFS per investigator assessment (HR, 0.34; 95% CI, 0.23–0.50). Median PFS per BIRC: vorasidenib, not estimable (NE; 95% CI, 22.1–NE); placebo, 11.4 months (95% CI, 11.1–13.9). TTNI also remained in favor of vorasidenib (HR, 0.25; 95% CI, 0.16–0.40). Median TTNI: vorasidenib, NE (95% CI, NE–NE); placebo, 20.1 months (95% CI, 17.5–27.1). No new safety signals emerged. CONCLUSIONS Vorasidenib is a targeted therapy for patients with predominantly non-enhancing mIDH1/2 diffuse glioma following surgical intervention, as shown in the INDIGO population. These additional 6 months of follow-up confirm the previously reported statistically significant and clinically meaningful improvements in PFS and TTNI with vorasidenib.

CTNI-47. A PHASE 1, RANDOMIZED, PERIOPERATIVE TRIAL OF VORASIDENIB AND IVOSIDENIB IN IDH1-MUTANT DIFFUSE GLIOMA: UPDATED RESULTS

Abstract BACKGROUND Vorasidenib (VOR) and ivosidenib (IVO) showed clinical activity in subjects with isocitrate dehydrogenase mutant (mIDH) gliomas. We evaluated both agents in a phase 1, randomized, open-label perioperative trial (NCT03343197). Pharmacodynamics, pharmacokinetics, and preliminary objective response rate (ORR) data as of 29-April-2020 were previously reported (Mellinghoff et al. Nat Med. 2023). Progression-free survival (PFS) data were not mature at publication time. We report here longer-term follow-up results, including mature PFS. METHODS Participants with grade 2/3 non-enhancing mIDH1 R132H mutant gliomas were randomized to VOR (50 or 10 mg QD), IVO (500 or 250 mg BID), or no treatment (control) for 4 weeks prior to planned surgery, with the option to continue treatment with VOR or IVO post-surgery. Secondary objectives included PFS, ORR assessed by Investigator in the post-surgery period, and safety profile of VOR and IVO. RESULTS Enrollment completed in April-2019. 49 participants were randomized, of which 46 participants (24 oligodendroglioma, 20 astrocytoma, 1 anaplastic oligodendroglioma, 1 anaplastic oligoastrocytoma) received treatment with either VOR (N=24) or IVO (N=22) after surgery. As of 23-September-2023 data cutoff, 11 (46%) and 5 (20%) participants remain on treatment for VOR and IVO, respectively. Median (range) post-operative treatment duration was 44.7 months (0.9–62.7) for VOR, 23.9 months (0–62.7) for IVO. Median (95% CI) PFS was 41.4 months (9.3, NE) for VOR and 38.6 months (18.3, NE) for IVO. ORR per Response Assessment in Neuro-Oncology in low-grade gliomas (RANO-LGG) was 46% for VOR and 27% for IVO. Longer safety follow up will also be presented. CONCLUSION These results provide further evidence of prolonged response using IVO and VOR immediately following surgery in predominantly non-enhancing gliomas. This longer-term follow-up is consistent with Phase 3 INDIGO study results where VOR demonstrated PFS benefit with manageable safety compared with placebo in participants with non-enhancing mIDH gliomas.

INNV-27. TEMOZOLOMIDE FOR PATIENTS WITH AGGRESSIVE PITUITARY TUMORS: A CASE SERIES

Abstract BACKGROUND Pituitary adenomas are often effectively managed with medical therapy, surgery, and radiation therapy. However, up to 15% of pituitary neoplasms exhibit rapid growth, invasive behavior, or, rarely, metastasize despite optimal standard treatments. Temozolomide is associated with a survival benefit for patients with these aggressive pituitary tumors. METHODS We present a case series of 8 patients with an aggressive pituitary tumor (APT) or pituitary carcinoma (PC) treated with temozolomide. RESULTS Eight patients (3 female, median age at diagnosis 44) with APT (n=6) or PC (n=2) were treated. A variety of pituitary tumor types were represented (1 prolactinoma, 5 corticotroph adenomas, 1 gonadotroph adenoma, 1 thyrotropinoma). Prior to temozolomide initiation, patients underwent a median 5 treatments including medical management (n=4), surgery (n=7), radiation therapy (n=7). Temozolomide was started at median 3.5 recurrence. Median treatment duration was 6 cycles (n=6, 150-200 mg/m2 days 1-5, 28-day cycles; n=1, 75 mg/m2, days 1-21, 28-day cycles). Seven patients experienced progression after temozolomide treatment, median progression-free survival (PFS) was 4 months. One patient remains on treatment, progression-free at 5 months. MGMT methylation status was assessed for 3 tumors. Among 2 patients with MGMT promoter methylated tumors, PFS was 4 months for one patient, the other remains on treatment. For one patient with MGMT promoter unmethylated corticotroph adenoma, PFS was 9 months. No ≥ grade 4 toxicities were noted. Most common toxicities were nausea (n=5), thrombocytopenia (n=3), and fatigue (n=2). CONCLUSION In this group of heavily pretreated patients, temozolomide monotherapy was well-tolerated and associated with median PFS of 4 months. Interestingly, PC patients had longer PFS at 9 months and 24 months. Our findings support use of single-agent temozolomide chemotherapy for patients with APT/PC, but further prospective analysis is needed to identify patients more likely to benefit from treatment and optimal timing of chemotherapy initiation.

Efficacy of durvalumab plus tremelimumab treatment for unresectable hepatocellular carcinoma in immunotherapy era clinical practice.

Since the development of tremelimumab plus durvalumab (Dur/Tre) for unresectable hepatocellular carcinoma (uHCC), it has been used as not only an initial but also later line treatment in clinical practice. This study aimed to elucidate clinical prognostic factors for progression-free survival (PFS) in Dur/Tre treatment cases. Enrolled were 183 uHCC patients treated with Dur/Tre from 2023 to May 2024 (median age, 74years; male patients, 152; Child-Pugh class A:B, 150:33; Barcelona Clinic Liver Cancer stage B:C,59:124; initial line use, 64). Clinical factors with prognostic influence on PFS in these patients were retrospectively evaluated. The median observation period was 7.2months (interquartile range, 3.2-10.4). History of atezolizumab plus bevacizumab (Atz/Bev) treatment was the only significant prognostic factor for PFS at introduction of Dur/Tre in multivariate analysis (hazard ratio 2.040, p=0.028) (median PFS: without vs. with=5.6 vs. 2.7months, p<0.001). Although immune-mediated adverse events (imAE) occurrence was only significant in univariate analysis, when objective response and disease control rates were examined according to imAE positivity (any grade) at the time of analysis, those were noted in 14.4% and 39.2%, respectively, of patients without imAE, while in patients with imAE (any grade), they were noted in 18.2% and 56.1%, respectively (p=0.523 and p=0.038, respectively). History of Atz/Bev treatment may be an independent clinical factor for poor PFS at Dur/Tre introduction.

PATH-44. CLINICAL AND RADIOGRAPHIC PREDICTORS OF PROGNOSIS IN ASTROCYTOMA, IDH-MUTANT, WHO GRADE 4

Abstract BACKGROUND Astrocytoma, IDH-mutant, WHO grade 4, are classified as a separate entity in the 2021 WHO classification of central nervous system tumors and have been poorly characterized in the literature. In this study, we report on the clinical outcomes in a large cohort of newly diagnosed grade 4 IDH-mutant astrocytoma. METHODS We retrospectively identified adult patients with astrocytoma, IDH-mutant, WHO grade 4, treated for their initial diagnosis at Dana-Farber Cancer Institute and Massachusetts General Hospital between 2010 and 2021. Clinical, molecular, and radiological characteristics were recorded, and their association with overall survival (OS) and progression-free survival (PFS) was measured by a log-rank test. If a proportional hazard assumption was violated, we compared the median OS and PFS between groups by the bootstrap method instead. RESULTS We identified 140 patients, with a median age at diagnosis of 37.9 years (range: 19-87) and male predominance (60.7%). MGMT promoter was methylated in 51.4%, and CDKN2A/B homozygous deletion was present in 40 cases (28.6%). Most tumors showed enhancement on the preoperative scan (n=108; 77.1%). Seventy percent of patients had subtotal resection, 25.7% had a gross total resection, and 4.3% had a biopsy. Most patients received standard chemoradiation followed by adjuvant temozolomide (n=103; 73.6%). The median OS was 6.9 years (95% CI: 4.5-9.2), and the median PFS was 3.3 years (95% CI: 2.1-4.4). OS and PFS were not associated with MGMT promoter methylation or the presence of enhancement on the preoperative scan. CDKN2A/B homozygous deletion was associated with worse OS (5.5 vs. 7.8 years, log-rank test-based p-value=0.036) but had no association with PFS (3.4 vs 2.6 years, bootstrap method-based p-value=0.488). CONCLUSIONS In our cohort of astrocytoma, IDH-mutant, WHO Grade 4, CDKN2A/B homozygous deletion had a negative prognostic impact, whereas MGMT promoter methylation status and enhancement on the preoperative scan did not affect survival outcomes.

Comparative analysis of efficacy and safety of combined immunotherapy and immune targeted therapy in the first-line treatment of advanced renal cell carcinoma: a real-world study

Aim. To compare of efficacy and safety of combined immune therapy (dual immune-oncology – IO combination therapies, IO-IO) and immune targeted therapy (ITT) in the first line treatment of patients with advanced renal cell carcinoma (RCC) treated in real world clinical practice. Materials and methods. The ambispective study enrolled patients with metastatic RCC aged ≥18 years, with measurable neoplastic lesions, who were treated with first-line IO-IO therapy or ITT. The primary endpoint was progression-free survival (PFS). Results. The study included data from 126 patients treated with IO-IO [46 (36.5%) patients of the IMDC intermediate and poor prognostic groups] or ITT [80 (63.5%) patients of all IMDC prognostic groups]. In a median follow-up of all patients of 16.1 (0.1–44.9) months, the median PFS was 16.1 (10.9–21.3) months, the median overall survival (OS) was not reached; one-year OS was 83.0%; the objective response rate on the first line of therapy was 44.4% with a complete response rate of 3.2%. The rate of tumor control was 88.1%. In the overall population, ITT versus IO-IO provided a significant benefit in terms of ORR (51.2% vs 32.6%; p=0.032), PFS (median 22.9 months vs 8.0 months; p=0.004) and one-year OS (87.5% vs 65.2%; p=0.042). In the IPTW population, multivariate analysis confirmed the independent prognostic significance of the treatment regimen for PFS (hazard ratio, 2.3; 95% confidence interval, 1.1–4.8; p=0.037) and OS (hazard ratio, 2.3; 95% confidence interval 1.1–4.8; p=0.037). No difference in the safety profile of IO-IO and ITT was identified. Conclusion. The results support the hypothesis that ITT is more effective than IO-IO in the first-line treatment of advanced RCC in patients of IMDC intermediate and poor prognostic groups.

Predicting first-line VEGFR-TKI resistance and survival in metastatic clear cell renal cell carcinoma using a clinical-radiomic nomogram.

This study aims to construct predicting models using radiomic and clinical features in predicting first-line vascular endothelial growth factor receptor-tyrosine kinase inhibitor (VEGFR-TKI) early resistance in metastatic clear cell renal cell carcinoma (mccRCC) patients. We also aim to explore the correlation of predicting models with short and long-term survival of mccRCC patients. In this retrospective study, 110 mccRCC patients from 2009 to 2019 were included and assigned into training and test sets. Radiomic features were extracted from tumor 3D-ROI of baseline enhanced CT images. Radiomic features were selected by Lasso method to construct a radiomic score. A combined nomogram was established using the combination of radiomic score and clinical factors. The discriminative abilities of the radiomic, clinical and combined nomogram were quantified using ROC curve. Cox regression analysis was used to test the correlation of nomogram score with progression-free survival (PFS) and overall survival (OS). PFS and OS were compared between different risk groups by log-rank test. The radiomic, clinical and combined nomogram demonstrated AUCs of 0.81, 0.75, and 0.83 in training set; 0.79, 0.77, and 0.88 in test set. Nomogram score ≥ 1.18 was an independent prognostic factor of PFS (HR 0.22 (0.10, 0.47), p < 0.001) and OS (HR 0.38 (0.20, 0.71), p = 0.002), in training set. PFS in low-risk group were significantly longer than high-risk group in training (p < 0.001) and test (p < 0.001) set, respectively. OS in low-risk group were significantly longer than high-risk group in training (p = 0.003) and test (p = 0.009) set, respectively. A nomogram combining baseline radiomic signature and clinical factors helped detecting first-line VEGFR-TKI early resistance and predicting short and long-term prognosis in mccRCC patients.