Concurrent Immunotherapy Research Articles

Radiotherapy in patients with brain metastases with and without concomitant immunotherapy: comparison of patient outcome and neurotoxicity

Background/AimRecently, immune checkpoint inhibitors (ICI) have been added to the treatment of brain metastases. While combining radiotherapy and ICI can enhance therapeutic effects, it might also increase the risk of severe autoimmune adverse events. This retrospective study aims to compare treatment responses and neurotoxicity in patients treated with radiotherapy alone versus those receiving a combination of radiotherapy and ICI.Patients and methodsAll patients with brain metastases who received radiotherapy at Hannover Medical School from 2017 to 2019 were included. The medical reports of all study participants were evaluated. Patients who received radiotherapy alone and those who received a combination of radiation and ICI were compared.ResultsA total of 248 patients were analyzed, with the most common tumor types being non-small cell lung cancer (NSCLC) and malignant melanoma. Half of the patients received whole-brain radiotherapy (WBRT) and the other half stereotactic radiotherapy (SRT). Of these, 29 patients received concurrent immunotherapy and radiotherapy, 30 completed immunotherapy before radiotherapy, and 29 started ICI after completing radiotherapy. Two cases lacked information on the duration of immunotherapy. Overall survival post-initial tumor diagnosis within the total cohort was 52 months, with significantly worse survival for patients with multiple brain metastases (p = 0.020). No significant differences in survival or incidence of neurological adverse events were observed between patients with or without ICI.ConclusionCombining radiotherapy and ICI did not significantly increase neurotoxicity or improve survival in this cohort, though the heterogeneity of the subgroups limits the generalizability of these findings.

Progression-free and overall survival of sequential platinum, taxane, and bevacizumab followed by immunotherapy may be equivalent to concurrent chemotherapy and immunotherapy among patients with recurrent or metastatic cervical cancer

Progression-free and overall survival of sequential platinum, taxane, and bevacizumab followed by immunotherapy may be equivalent to concurrent chemotherapy and immunotherapy among patients with recurrent or metastatic cervical cancer

Immune checkpoint blockade effect on immunologic and virologic profile of five cancer patients living with human immunodeficiency virus (HIV) infection.

Immune checkpoint inhibitors (ICI) have changed the prognostic outlook for several malignancies. Despite the unprecedented durable responses and improvement in survival outcomes with ICIs, exclusion of oncology patients living with human immunodeficiency virus (HIV) from most ICI-related trials has limited utility of these agents. Clinical outcomes related to concomitant use of antiretroviral therapy and ICI remain unclear. We present a case series based on our institution's experience to address this unmet need of clinical outcomes with ICI in oncology patients living with HIV. Electronic medical records were queried to identify patients living with HIV who were also diagnosed with cancer and treated with ICI from May 2019 to September 2022. A total of five patients were on concurrent antiretroviral therapy and immunotherapy. From an efficacy perspective, three patients were observed to have a response (one complete response, one partial response, and one stable disease). There were three patients with known cluster of differentiation (CD4 + ) levels who had an increase in CD4 + cell count with ICI treatment. The HIV viral load remained undetected in most of the patients on ICI treatment. No confirmed immune-related adverse effects were documented for any patients in this review. Immune checkpoint inhibitors may be efficacious and tolerable for treatment of cancer in patients living with HIV. Upward trends in CD4 + cell counts observed in this case series suggest that immune checkpoint inhibitors may enhance HIV disease control. Further research is needed for this patient population to supply more robust evidence for clinical practice.

The optimal stereotactic body radiotherapy dose with immunotherapy for pulmonary oligometastases: a retrospective cohort study.

Stereotactic body radiotherapy (SBRT) is a precise and effective treatment for pulmonary oligometastases, offering high local control (LC) rates. However, the optimal SBRT dose when combined with immunotherapy remains unclear, and there is a lack of comprehensive studies focusing on dose optimization in this setting. This study addresses this knowledge gap by exploring different SBRT dose regimens and their impact on progression-free survival (PFS), overall survival (OS), and LC in patients receiving concurrent immunotherapy, offering novel insights into the synergistic effects of these treatments. A retrospective cohort study was conducted of 101 patients with 141 pulmonary oligometastases treated from April 2018 to April 2022. Inclusion criteria included patients with a maximum of five lung metastases and an Eastern Cooperative Oncology Group performance status of ≤2. Patients received SBRT with doses ranging from 50-70 Gy in 5-10 fractions. Follow-up was performed quarterly, and the best dose was determined by comparing survival outcomes across different dose groups. The patients received SBRT with doses ranging from 50-70 Gy in 5-10 fractions. Patient demographics, tumor characteristics, treatment details, and outcomes were collected. The Kaplan-Meier method was used for the survival analysis, and Cox regression models were used to identify prognostic factors for LC, PFS, and OS. The median follow-up for the 101 patients was 22.4 months (range, 1-58 months). The cohort comprised 82.2% male patients with a median age of 64 years (range, 36-81 years). The majority of the patients (64.4%) had primary tumors originating from non-lung sites, with adenocarcinoma being the predominant histological subtype (47.5%). The median tumor size was 13.5 mm. Across the entire cohort, the median OS was 39 months, and the median PFS was 11 months. Pre-treatment with immunotherapy significantly improved outcomes: the PFS increased to 13 months compared to 7 months for those who did not receive immunotherapy [P=0.02, hazard ratio (HR) = 0.523, 95% confidence interval (CI): 0.302-0.906], and the OS was also significantly improved (P=0.008, HR =0.411, 95% CI: 0.214-0.792). The SBRT regimen of 60 Gy in 10 fractions provided the best outcomes, with a median OS of 39 months, a median PFS of 10 months, and a LC rate of 92.4%, with relatively low toxicity compared to other regimens. SBRT is a potent, minimally invasive option for managing pulmonary oligometastases, especially when preceded by immunotherapy. The 60 Gy in 10 fractions regimen demonstrated significant efficacy in terms of OS and LC, while maintaining manageable toxicity. Although the retrospective nature of the study introduces some selection bias, this dose regimen appears to offer a promising therapeutic option for pulmonary oligometastases. Further validation through well-designed prospective studies would help confirm the optimal SBRT dose and clarify the role of immunotherapy in this setting.

Stereotactic Radiosurgery for 1-10 Brain Metastases to avoid Whole-Brain Radiotherapy - Results of the CYBER-SPACE Randomized Phase 2 Trial.

Stereotactic Radiosurgery (SRS) is an emerging alternative to whole-brain radiotherapy (WBRT) for treating multiple brain metastases (BM), reducing toxicity and improving tumor control. The CYBER-SPACE trial compared SRS based on either SPACE or MPRAGE MRI sequence for avoiding or delaying WBRT in patients with 1-10 BM. Patients with 1-10 untreated BM were randomized 1:1 to receive SRS of all lesions based on either SPACE or MPRAGE MRI sequences. If subsequently new BM occurred, SRS was repeated. WBRT was indicated upon occurrence of >10 new BM, leptomeningeal disease or exhausted SRS-radiotolerance. The primary outcome was freedom from WBRT indication (WBRTi). Secondary outcomes included overall survival (OS), safety, and quality of life. 202 patients were randomized; SPACE n=99, MPRAGE n=103. 12-month WBRTi-free survival was 77.1% (95%-CI: 69.5%-83.1%) overall, 78.5% (95%-CI: 66.7%-86.5%) for SPACE, and 76.0% (95%-CI: 65.2%-83.9%) for MPRAGE (HR=0.84, 95%-CI: 0.43-1.63, p=0.590). Patients with 5-10 BM had shorter WBRTi-free survival (HR=3.13, 95%-CI: 1.53-6.40, p=0.002). Median OS was 13.1 months overall, 10.5 months for SPACE, and 15.2 months for MPRAGE (HR=1.10, 95%-CI: 0.78-1.56, p=0.585). Neurologic death rate was 10.1%. Predictors for longer OS included Karnofsky Performance Status >80% (HR=0.51, 95%-CI: 0.33-0.77, p=0.002) and concurrent immunotherapy (HR=0.34, 95%-CI: 0.23-0.52, p<0.001). The more sensitive SPACE sequence did not improve outcomes over MPRAGE. SRS with thorough monitoring and immediate re-treatment for new lesions decreases the need for WBRT and achieves low neurologic death rates. SRS should be considered a favorable alternative to WBRT for patients with 1-10 BM.

Novel Effective Therapeutic Regimen for Recurrent/Metastatic Head and Neck Squamous Cell Cancer: Concurrent Triple Oral Metronomic Chemotherapy and Immunotherapy.

Novel Effective Therapeutic Regimen for Recurrent/Metastatic Head and Neck Squamous Cell Cancer: Concurrent Triple Oral Metronomic Chemotherapy and Immunotherapy.

Efficacy and safety of the combination of tisleizumab with chemoradiotherapy in oligorecurrence esophageal squamous cell carcinoma: A prospective phase II study.

4057 Background: The postoperative recurrence and metastasis rate of esophageal squamous cell carcinoma (ESCC) remains high and prognosis is poor. PD-1 immune checkpoint inhibitors have shown efficacy in targeting advanced esophageal cancer. This phase II study aims to explore the efficacy and safety of concurrent chemoradiotherapy and immunotherapy for ESCC patients with oligometastatic recurrence after radical surgery. Methods: This phase II study enrolled ESCC patients from 3 hospitals in China, diagnosed oligometastatic recurrence after radical surgery. The 1st stage, with 10 patients enrolled, was designed to explore the safety level and the 2nd stage was to explore efficacy. The oligorecurrence is defined as progression occurring three months after the operation with no more than three metastatic regions. The local recurrence was defined as tumor bed or anastomotic recurrence. The regional lymph node recurrences were regarded as mediastinal region and celiac lymph, respectively. The distal recurrences were considered as supraclavicular, retroperitoneal region and other distal organs. All of the positive regional lymph nodes were collectively counted as one lesion if regional lymph node recurrences existed. Tisleizumab was delivered on D1,22. Nab-paclitaxel 150mg/m2 (starting on D2,23) and cisplatin, 75mg/m2(starting on D2-4,22-24) were administered for two cycles. The radiotherapy was delivered with 50.4-60Gy, 1.8-2Gy per fraction. After CRT, patients received Tisleizumab every 3 weeks for 3-6 months and 2-4 cycle consolidation chemotherapy. The primary endpoint was 1-year OS, the second endpoints were 1-year PFS, ORR and toxicities. Results: Between Jan 2021 and May 2023,50 patients were screened for enrolment and 44 patients met the eligibility criteria. The metastatic regions were made up by the local (15.9%),regional (47.7%), distal (13.6%) and mixed recurrence (22.7%). In the 1st stage, one patient had a grade-3 Immune-related erythra out of ten patients. All patients were delivered chemoradiotherapy, 36(81.8%) patients had completed two cycles of immunotherapy. The ORR rate was 84.1%. During concurrent chemoradiotherapy, the incidence of grade≥3 treatment-related adverse events was nausea (9.1%), vomit (4.5%), anorexia (4.5%), leukopenia (13.6%), hepatitis (2.3%), radiation esophagitis (1.4%), erythra (4.5%). There were 5 cases of Immune-related adverse, including 2 cases of erythra, 1 case of hypothyroidism, hepatitis, gastroenteritis, respectively. With the median follow-up time of 19 months (range:4-30 months), 1-year OS and PFS was 83.2% and 79.2%. The median OS and the median PFS were not reached. Conclusions: Concurrent chemoradiotherapy and immunotherapy yielded satisfactory 1-year OS rate and manageable toxicities in oligometastatic recurrence patients with ESCC after radical surgery. Clinical trial information: NCT04821765 .

Distinct tumor microbiome and metabolomic profiles to inform responses of patients with esophageal cancer to neoadjuvant chemoradiotherapy and immunotherapy.

4084 Background: Preclinical and clinical data indicate that neoadjuvant chemoradiotherapy (CRT) may prime an anti-tumor immunological response in esophageal cancer driven by intratumoral CD8+ T cells. However, responses to neoadjuvant therapy can vary widely across patients. The microbiome, a novel and potentially modifiable biomarker of immunotherapy response, may inform neoadjuvant response. Methods: Fecal and tumor samples were collected from patients with stage II-III resectable distal esophageal or gastroesophageal junction carcinoma treated with neoadjuvant immunotherapy followed by chemoradiotherapy (CRT) and immunotherapy (IO). Patients on arm A (n=15) received 2 cycles of induction with nivolumab plus 3 additional cycles with CRT. Patients on arm B (n=10) received nivolumab and relatlimab on a similar induction schedule, but concurrent IO and CRT resulted in immune related adverse events and a protocol amendment to CRT (NCT03044613). We examined fecal (n=19) and tumor (n=12) patient samples across both arms using 16S rRNA amplicon sequencing and high-resolution taxonomic assignment. Additionally, fecal samples were analyzed using an untargeted panel (General Metabolics) and pathway analysis was performed using Metaboanalyst (v6.0). Results: The fecal microbiome of patients with pathological complete response (pCR) grouped in distinct clusters compared to patients without pathological complete response (non-pCR) using Bray-Curtis (p &lt; 0.001). Patients with &gt;10% and &lt;10% residual tumor grouped similarly but were significantly different from patients with 0% residual tumor (p &lt; 0.001). On a linear discriminant axis, the top 10 abundant bacteria were significantly increased in pCR compared to non-pCR (p &lt; 0.001). After FDR correction, six bacteria had significantly differing abundances. Bacteroides finegoldii, Paraprevotella clara, Ruminococcus callidus, and Roseburis inulinivorans were significantly enriched in pCR patients. Clostridiales and Bacteroides were significantly enriched in non-pCR patients. Fecal metabolomic analysis demonstrated six significant metabolites: in non-pCR, ropinirole, valine, phenylalanine, and isoleucine were enriched; in pCR, C16cer and D-urobilinogen were enriched (p &lt; 0.05). Patients with improved neoadjuvant response had significantly higher abundances of Bacteroides and corresponding C16cer levels. Pathway analysis revealed significant involvement in aminoacyl-tRNA biosynthesis and sphingolipid metabolism. Conclusions: Patients with complete responses to combined CRT and IO for operable esophageal cancer had distinct fecal microbiome profiles as well as metabolomic pathways. These results may be useful to further characterize and predict patients who have improved responses to neoadjuvant therapy and serve as a basis for therapeutic intervention.

Impact of timing of immunotherapy in survival among patients with advanced lung adenocarcinoma treated with first-line immunochemotherapy: A propensity score matching.

e20560 Background: Immunochemotherapy combinations have been the mainstream first-line standard treatment of advanced non-small cell lung cancer (NSCLC), wherein concurrent chemotherapy and immunotherapy are conventionally fixed to an established dosing regimen. Few studies had suggested the remarkable impact of the timing of immunotherapy on immunochemotherapy combined therapy. However, this issue has not been addressed in advanced NSCLC cohort. Methods: This study was a retrospective analysis of 532 patients with advanced lung adenocarcinoma (LUAD) without EGFR/ALK mutations who underwent immunochemotherapy as first-line systemic treatment between June 2018 to June 2022 at 3 facilities. Patients were divided into two groups (induced and non-induced) according to the different timing of immunotherapy in combined therapy, which defined induced as receiving 1 or more cycles of full-dose chemotherapy alone before concurrent immunochemotherapy. The bias between induced and non-induced groups was minimized with Propensity Score Matching (PSM). Patients outcomes, including progression-free survival (PFS) and overall survival (OS), were compared between the two groups by Kaplan-Meier survival curves and Cox regression analyses. Results: Survival analysis showed that both PFS and OS of the induced chemotherapy group patients were significantly longer than that of non-induced group (PFS: 14.63 months vs. 10.13 months, p = 0.004; OS: Not reached vs. 20.27 months, p = 0.0013). In the COX regression, after adjusting for confounders, induction chemotherapy was found to be a remarkable favorable factor for both PFS and OS (PFS: HR = 0.73, p= 0.018; OS: HR = 0.69, p= 0.034). After pretreatment features and treatment parameters were included in PSM, 104 patients were identified in each groups with matched characteristics, and moreover, the results of survival analysis remained consistent and showed significant difference between induced and non-induced group (PFS: 14.63 months vs. 10.23 months, p = 0.029; HR = 0.71, p= 0.030. OS: Not reached vs 18.27 months, p = 0.0013; HR = 0.52, p= 0.002). Conclusions: For advanced LUAD patients treated with first-line immunochemotherapy combinations, the timing of immunotherapy had significant impact on prognosis, which suggested notable benefit of induction chemotherapy before concurrent immunochemotherapy.

27P Concurrent chemoradiotherapy and immunotherapy for locally advanced cervical cancer: A cost-effectiveness analysis based on the KEYNOTE-A18 trial

27P Concurrent chemoradiotherapy and immunotherapy for locally advanced cervical cancer: A cost-effectiveness analysis based on the KEYNOTE-A18 trial

Real-world safety and efficacy of concurrent immunotherapy and thoracic chemoradiotherapy: A multi-institutional analysis.

e23262 Background: Despite the success of Immune checkpoint inhibitors (ICIs) as consolidation following concurrent chemoradiotherapy (CCRT), 22% to 30% of patients still cannot be treated with durvalumab due to progression or adverse events (AEs) during or after CCRT. Concurrent ICIs with CCRT would offer the opportunity to receive ICIs and may provide treatment benefit to a greater proportion of patients. In this study, we performed a multicenter investigation to evaluate the safety and efficacy of ICIs and chemotherapy with concurrent thoracic radiotherapy. Methods: All patients from three institutions who underwent ICIs and concurrent thoracic radiotherapy were included. The rate of 12-month progression-free survival (PFS) was estimated using the Kaplan-Meier method and evaluated with 95% CIs calculated using the Greenwood formula. Therapy-related pneumonitis (TRP) and esophagitis (TRE) were defined per CTCAE v5.0. Statistics utilized logistic regression modeling and receiver operating characteristic (ROC) analysis. Results: 69 patients (median [range] age, 62 [52-76]; 61 [88.4%] male; median follow-up 30.4 months) were collected, including 18 (26.1 %) cases of non-small cell lung cancer (NSCLC), 26 (37.7 %) cases of small cell lung cancer (SCLC), and 25 (36.2 %) cases of esophageal cancer (EC). The 12-month PFS rates in NSCLC, SCLC and EC were 72.2%, 69.2% and 72.0%, respectively. The median PFS in NSCLC and SCLC was 24.3 and 13.1 months, and not reached (mean 29 months) for EC. The incidences of all-grade TRP and TRE were 60.7% and 57.7%, respectively. Grades 1-5 TRP occurred in 15.9%, 30.4%, 8.6%, 1.4%, and 0, respectively. Grades 1-5 TRE occurred in 20.2%, 28.9%, 8.6%, 0, and 0, respectively. On multivariable analysis, age and MLD significantly predicted for any-grade and grade ≥2 TRP. Only age significantly predicted for grade ≥3 TRP. ROC analysis was able to pictorially model RP risk probabilities for a variety of MLD and age thresholds. Conclusions: This real-world study can be helpful for understanding the true efficacy and toxicity of ICIs and chemotherapy with concurrent thoracic radiotherapy given the lack of robust clinical data. Close monitoring should be recommended in this patient population during RT and follow-up.

Stereotactic radiosurgery for brain metastasis from cholangiocarcinoma.

Accounting for approximately 15% of primary liver cancers and 3% of gastrointestinal malignancies, cholangiocarcinoma (CCA) poses a serious health concern given its high mortality rate. Managing brain metastases (BMs) from CCA is challenging because of their rarity and poor prognosis, with little guidance on treatment from the literature. In this study, the authors aimed to evaluate the safety and efficacy of stereotactic radiosurgery (SRS) in managing BMs from CCA. This multicenter retrospective study included 13 CCA patients with 41 BMs treated with SRS from October 2006 to April 2022 at eight institutions affiliated with the International Radiosurgery Research Foundation. Inclusion criteria were a CCA diagnosis, an age over 18 years, no other malignancies, single-fraction SRS treatment for BMs, and at least one follow-up image. Data on demographics, tumor characteristics, treatment details, and outcomes were collected. The primary endpoints were local control (LC), intracranial progression-free survival (PFS), and overall survival (OS). The secondary endpoint was the development of adverse radiation effects (AREs). The median radiological follow-up was 5 months (range 1-18 months). At the last follow-up, LC was achieved in 39 (95.1%) of 41 BMs. New distant metastases were observed in 3 patients (23.1%), and the mean intracranial PFS was 9.4 months (95% CI 6.5-12.3 months). Six-month and 1-year OS rates were 38.5% and 11.5%, respectively, and the median OS was 6 months (95% CI 4.9-7.2 months). Concurrent immunotherapy was associated with a high risk of local failure (HR 29.665, 95% CI 1.799-489.206, p = 0.018), and the absence of systemic chemotherapy before SRS was linked to reduced OS (HR 6.658, 95% CI 1.173-37.776, p = 0.032). Regarding AREs, only 1 patient (7.7%) experienced right hemiparesis and was treated with corticosteroid therapy. SRS is an effective option for managing BMs in CCA patients, showing promise in LC and a high safety profile.

Abstract 5895: N17350 kills cancer cells, spares immune cells, and regresses CDX tumors from chemotherapy naive and experienced patients

Abstract Background. While multiple studies have demonstrated improved clinical outcomes in patients receiving concurrent chemotherapy and immunotherapy, clinical synergy may be limited by the destructive effects of DNA-damaging chemotherapy on non-cancer cells, including key constituents of anti-tumor immunity (e.g. mature T cells). Furthermore, when first-line chemotherapy fails, subsequent lines of chemotherapy produce lower response rates. Thus, new approaches that eradicate cancer cells while preserving immune cells may be required to more efficiently induce anti-tumor immunity as monotherapy or in combination with immunotherapy. Neutrophil elastase (ELANE), a neutrophil-derived serine protease, kills a wide range of cancer cells without harming immune cells through a unique mechanism involving histone H1 and the death domain of CD95. Here, we compared N17350, an optimized biologic leveraging the ELANE pathway, and chemotherapies for their ability to kill cancer cells and preserve immune cells from primary tumors of ovarian cancer (OvCa) patients and evaluated efficacy in OvCa patient cell-derived xenografts (CDXs) and a 4T1 model of metastatic breast cancer. Methods. For in vitro studies, cancer cells and CD45+ immune cells were isolated from primary tumors of chemotherapy naïve and experienced OvCa patients. Cells were treated with N17350, oxaliplatin, or doxorubicin 24h post-isolation, and viability was quantified by calcein-AM. For in vivo studies, primary OvCa cells were injected into nude mice to create CDX models. Mice were treated with 2 doses of N17350 (400μg/100mm3, intratumoral) or carboplatin (100mg/kg, intraperitoneal), and effects on tumor growth were quantified. In 4T1 model, N17350 was compared to oxaliplatin, alone or in combination with anti-CTLA4, and effects on tumor growth and immune profile were assessed. Results. N17350 killed primary cancer cells from all OvCa patients tested but was well tolerated by CD45+ tumor immune cells from the same patients. In contrast, doxorubicin and oxaliplatin showed similar toxicity to both cell types. N17350 killed cancer cells from chemotherapy naïve and experienced patients with equal efficacy, while doxorubicin and oxaliplatin showed less efficacy in patients previously treated with chemotherapy. N17350 rapidly regressed tumors in all OvCa CDX models and exhibited markedly improved efficacy over carboplatin. In the 4T1 model, N17350 outperformed oxaliplatin in terms of regressing tumors, elevating tumor immune cells, and combining with anti-CTLA4. Conclusions. Our data demonstrate that N17350 kills OvCa tumors in vitro and in vivo while sparing CD45+ immune cells in both chemotherapy naïve and experienced patients. Together with previous data showing that N17350 induces immunogenic tumor cell death, these findings suggest that N17350 could improve clinical outcomes compared to chemoimmunotherapy. Citation Format: Chang Cui, Ravindra Gujar, Christine Lee, Maria Fumagalli, Nicole Martinez, Hannah Liu, Nicole Grigaitis, Sonia Feau, Afshin Bahador, Alain P. Algazi, Lev Becker. N17350 kills cancer cells, spares immune cells, and regresses CDX tumors from chemotherapy naive and experienced patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5895.

Navigating Adjuvant Radiotherapy Advancements in Endometrial Cancer within the Molecular Classification Landscape: A Comprehensive Overview

ABSTRACT This review’s objective is to consolidate knowledge on key endometrial cancer (EC) biomarkers and their molecular underpinnings within the context of the modern era of molecular classification. The review also encompasses an overview of the molecular subtyping of EC, offers recommendations for treatment approaches, and insights into ongoing radiation trials. By integrating clinical and pathologic features to inform treatment decisions, including concurrent chemoradiation, chemotherapy, targeted therapies, endocrine therapy, and immunotherapy, there is potential to enhance EC management and provide patients with more effective and tailored treatment options. Molecular classification offers the foundation for tailor-made treatment strategies, enabling the development of highly precise and personalized plans. This reduces the utilization of unnecessary treatments, offering the prospect of improved outcomes and ultimately elevating the quality of life for patients with EC.

Carboplatin and paclitaxel after anti-PD-1 or anti-PD-L1 antibody therapy in recurrent and/or metastatic squamous cell carcinoma of head and neck.

The impact of concurrent chemotherapy and immunotherapy has been well characterized in patients with recurrent and metastatic head and neck squamous cell carcinoma (RM-SCCHN). Here, we report outcomes in patients treated sequentially with immune checkpoint inhibition (ICI) followed by carboplatin and paclitaxel. Patients with RM-SCCHN treated with ICI followed by carboplatin/paclitaxel at a single institution were identified retrospectively. ICI therapy history, p16, and PD-L1 status were collected. The best overall response was assessed by RECIST v1.1. Twelve patients met inclusion criteria. Eight patients received pembrolizumab, three durvalumab, and one nivolumab. The median duration of ICI was 3.44 months, median PFS was 5.8 months, and median OS was 15.2 months. 66.7% of patients had an objective response on carboplatin/paclitaxel. Carboplatin/paclitaxel can induce objective responses in patients with prior treatment with ICI and clinical outcomes in this small series compare favorably to those seen in ICI naïve patients.

NIMG-05. CHARACTERIZATION OF LONG-TERM METABOLIC CHANGES OF BRAIN METASTASES AFTER TREATMENT WITH STEREOTACTIC RADIOSURGERY USING SERIAL FET PET IMAGING

Abstract BACKGROUND In the present study, we characterized the long-term metabolic changes of brain metastases after treatment with stereotactic radiosurgery (SRS) by serial PET imaging using the radiolabeled amino acid O-(2-[18F]-fluoroethyl)-L-tyrosine (FET). We hypothesized that this approach is of considerable clinical value in differentiating between radiation-induced changes and local brain metastasis relapse. Patients and METHODS From 2010-2020, we retrospectively identified patients with brain metastases from solid extracranial primary tumors who (i) were treated with SRS with or without concurrent immunotherapy using checkpoint inhibitors, (ii) had equivocal MRI findings after SRS, and (iii) subsequently underwent two or more additional FET PET scans during follow-up for long-term evaluation. Mean tumor-to-brain ratios (TBR) were obtained. Diagnostic performances were calculated using receiver operating characteristic curve analyses. Diagnoses were confirmed by neuropathological evaluation (29%) or clinicoradiologically (71%). RESULTS We identified 14 patients with 42 FET PET scans (median number, 3; range, 2-4). Concurrent to SRS, 4 patients (29%) were treated with checkpoint inhibitors. Following SRS, equivocal MRI findings occurred after a median time of 7 months (range, 2-62 months). Subsequently, FET PET scans were acquired over a median 16 months (range, 7-99 months). Nine patients (64%) had radiation-induced changes, and five had local brain metastases relapse. TBRs calculated from the last available FET PET scan showed the highest accuracy (93%) in identifying radiation-induced changes (threshold, 1.95; P=0.011). In lesions consistent with local brain metastases relapse, TBR increased considerably over time (median increase, 17%; range, 11% - 32%). In contrast, in lesions considered as radiation-induced changes, TBR remained stable or even decreased (median change, -4%; range, -44% - 11%). The TBR evolution over time significantly differed between the two groups (P=0.011). CONCLUSIONS Serial FET PET imaging has a high diagnostic accuracy for characterizing long-term changes of brain metastases after treatment with stereotactic radiosurgery.

CTIM-35. INB-400 PHASE 1B/2 DRUG RESISTANT IMMUNOTHERAPY WITH ACTIVATED, GENE MODIFIED ALLOGENEIC OR AUTOLOGOUS ΓΔ T CELLS IN COMBINATION WITH MAINTENANCE TEMOZOLOMIDE RECURRENT OR NEWLY DIAGNOSED GLIOBLASTOMA

Abstract Gamma delta (gd) T cells are innate immune cells that synergistically target cancer cells via NKG2D ligands (NKG2D-L) upregulated by chemotherapy. INB-200, a Phase 1 trial, demonstrated the safety and efficacy of autologously (auto) derived genetically modified drug resistant immunotherapy (DRI) gd T cells combined with maintenance temozolomide (TMZ) to treat newly diagnosed (ND) patients with GBM. Initiation of , a 3-arm phase 1b/2 study confirming the efficacy of the auto product in ND GBM and the safety and efficacy of an allogeneic (allo) product in both ND and relapsed GBM has begun. Arm A assesses the auto product in ND GBM patients with 1x107 cells delivered on Day 1 of cycles 1-6 along with TMZ maintenance therapy per the Stupp regimen. In the Phase 1b arm, the haploidentical allo product, will be assessed for safety in 6 relapsed GBM patients who will receive 1x107 cells in combination with 150mg/m2 of TMZ on Day 1 of every six 28-day cycles. Arm B will continue enrollment of relapsed patients following the Phase 1b and Arm C will test the safety of the allo derived product in ND, GBM patients. In Arm C, patients will receive 1x107 allo DeltEx DRI cells on Day 1 of cycles 1-6 in combination with TMZ maintenance. Cells are administered through a Rickham catheter in all arms. Primary endpoints for the Phase 1b define the RP2D and subject/ product characteristics to optimize manufacturing, while Phase 2 endpoints will determine the 12 mos OS rate for Arms A &amp; C and 9 mos OS rate for Arm B. Eligible patients are adults with IDH-wt ND or relapsed GBM with no concurrent TTF or immunotherapy, willing to place an indwelling Rickham catheter. Allo arm patients must have a haploidentical donor. Fifteen US centers will conduct study.

A retrospective comparative cohort study: concurrent versus consolidative immunotherapy with chemoradiotherapy in EGFR- or ALK-negative unresectable stage III non-small cell lung cancer

A retrospective comparative cohort study: concurrent versus consolidative immunotherapy with chemoradiotherapy in EGFR- or ALK-negative unresectable stage III non-small cell lung cancer

Impact of Concurrent Targeted Therapy and Immunotherapy on the Incidence of Radiation Necrosis Following Stereotactic Radiosurgery for Brain Metastases

The management of metastatic disease has evolved with the advent of immunotherapy (IT) and targeted therapies (TT). Yet, there is limited understanding of the toxicity associated with combining these agents with stereotactic radiosurgery (SRS). We retrospectively evaluated the impact of concurrent systemic therapy (ST) on the risk of radiation necrosis (RN) following LINAC-based SRS for brain metastases (BM). A retrospective study was conducted within an integrated health care system from March 2017 to December 2021 of 313 patients who underwent SRS or fractionated SRS in 3 or 5 treatments to a total of 1,644 intact BM. Post-operative cavity SRS and re-irradiated lesions were excluded. RN was diagnosed using perfusion MRI, contrast clearance MRI, or serial standard MRI and graded using CTCAE (v.5). Concurrent ST was defined as administration within 1 month preceding or following SRS. Overall survival (OS) and risk of RN were estimated by the Kaplan-Meier method. Logistics regression analyses were performed to compare risk of RN in patients who received concurrent systemic therapy to those who did not, adjusted for PTV volume and receipt of whole brain radiotherapy (WBRT). Median follow-up was 12.2 months. Median age was 64 years (range: 24-92). Primary sites per patient included lung (48.9%), breast (18.2%), melanoma (11.5%), kidney (6.1%), and other (15.3%). Median total lesions treated was 3 (range: 1-44); 65.9% of patients underwent 1 course of SRS, 23.4% underwent 2 courses, 6.2% underwent 3 courses, 4.5% underwent >4 courses. Seventy-six (24.2%) patients received WBRT. Overall, 70.6% of lesions received concurrent ST including chemotherapy (CT) (32.5%), IT (26.8%), and TT (27.6%); 16.4% received a combination of ST. Median OS was 12.9 months (95% CI: 10.4-15.5). RN was observed in 50 (3.0%) lesions in 42 (13.4%) patients. The 1-year risk of RN was 4.0% per lesion and 15.4% per patient. Symptomatic RN (SRN) was observed in 31 (1.9%) lesions in 24 (7.7%) patients. The 1-year risk of SRN was 2.7% per lesion and 10.1% per patient. When compared to lesions treated without concurrent systemic therapy, there was no increased risk of RN observed in lesions treated with concurrent CT (adjusted OR = 0.86 (95% CI: 0.43-1.73) p = 0.68), concurrent IT (adjusted OR = 0.84 (95% CI: 0.41-1.71) p = 0.84), or concurrent TT (adjusted OR = 0.57 (95% CI: 0.25-1.30) p = 0.18). Treatments of SRN included dexamethasone (96.8%), bevacizumab (22.6%), and laser interstitial thermal therapy (6.5%). Concurrent IT and TT appears well-tolerated in patients who undergo SRS for treatment of BM. No increased risk of RN was observed in lesions treated with concurrent IT or TT compared to lesions treated in the absence of concurrent ST. Further prospective and agent-specific evaluation is necessary to confirm these findings.

Differential Response in Quantitative MRI Parameters Detected in Head and Neck Cancer Patients Treated with Concurrent Immunotherapy during Hypo-Fractionated MR-gRT

Recently, multiple clinical trials have demonstrated success of PD-1/PD-L1-targeted immune checkpoint inhibition (ICI) in recurrent and metastatic head and neck cancer (HNC). However, three large clinical trials combining PD-1/PD-L1-targeted ICI with RT or chemo-RT (CRT) in the definitive management of HNC have shown no benefit of combination therapy with ICI over RT or CRT alone. Our overarching hypotheses are: i) hypo-fractionation may ultimately better synergize with ICI compared to conventional RT regimens, and ii) immunologic changes in the tumor microenvironment may be detectable using quantitative MRI (qMRI) parameters collected during RT. Seven patients treated with hypo-fractionated MR-guided RT of 50 Gy in 15 fractions (DEHART, NCT04477759) were included in the study. Four patients (Group 1) were treated with concurrent atezolizumab (a monoclonal antibody) and three patients (Group 2) were treated with RT alone. Daily DWI, T1 mapping, and T2 mapping sequences were acquired on a 1.5T MR-Linac in the idle time during adaptive plan generation. Median ADC, T1, T2, and Dslow (derived from b-values 150 and 550 s/mm2) values were extracted from physician-defined GTV and manually constructed posterior paraspinal muscle contours, the latter serving as a control. Wilcoxon signed rank tests were conducted using pre/post treatment data for each qMRI parameter. GTV ADC, Dslow, T2, and T1 increased for both patient groups over the course of treatment with significant differences in ADC, Dslow, and T2 detected between fractions 1 and 15 for all patients studied (p = 0.0156, p = 0.0156, and p = 0.0469, respectively). No significant differences were detected in control qMRI parameters pre/post treatment. No significant differences in ADC, Dslow, and T2 were detected between groups' fractions 1 and 15 in these small cohorts. However, interestingly, we observed a differential change in the increase of median GTV T2 and Dslow values during fractions 10-12 in Group 1 compared to Group 2, suggesting this time interval may prime the anti-tumor immune response. Combining hypo-fractionated RT with ICI leads to a differential response in quantitative MRI (qMRI) parameters in HNC patients. These results suggest that qMRI parameter changes ten days following the start of RT may reflect a critical juncture in the anti-tumoral immune response when ICI is combined with hypo-fractionated RT.