Immune-related Response Criteria Research Articles

Durvalumab plus pazopanib combination in patients with advanced soft tissue sarcomas: a phase II trial

We aimed to determine the activity of the anti-VEGF receptor tyrosine-kinase inhibitor, pazopanib, combined with the anti-PD-L1 inhibitor, durvalumab, in metastatic and/or recurrent soft tissue sarcoma (STS). In this single-arm phase 2 trial (NCT03798106), treatment consisted of pazopanib 800 mg orally once a day and durvalumab 1500 mg once every 3 weeks. Primary outcome was overall response rate (ORR) and secondary outcomes included progression-free survival (PFS), overall survival, disease control rate, immune-related response criteria, and safety. The ORR was 30.4% and the trial met the pre-specified endpoint. The median PFS was 7.7 months (95% confidence interval: 5.7–10.4). The common treatment-related adverse events of grades 3–4 included neutropenia (9 [19.1%]), elevated aspartate aminotransferase (7 [14.9%]), alanine aminotransferase (5 [10.6%]), and thrombocytopenia (4 [8.5%]). In a prespecified transcriptomic analysis, the B lineage signature was a significant key determinant of overall response (P = 0.014). In situ analysis also showed that tumours with high CD20+ B cell infiltration and vessel density had a longer PFS (P = 6.5 × 10−4) than those with low B cell infiltration and vessel density, as well as better response (50% vs 12%, P = 0.019). CD20+ B cell infiltration was identified as the only independent predictor of PFS via multivariate analysis. Durvalumab combined with pazopanib demonstrated promising efficacy in an unselected STS cohort, with a manageable toxicity profile.

Nivolumab and ipilimumab in advanced non small cell lung cancer previously treated with PD1 axis inhibition.

9121 Background: Nivolumab combined with ipilimumab is currently one of many first line treatment options for patients with advanced non-small cell lung cancer (NSCLC). The benefit of this regimen in patients with NSCLC previously treated with a programmed death 1 (PD1) axis inhibitor is unclear. Methods: We conducted a phase II study (NCT03262779) of nivolumab and ipilimumab in patients with PDL1 unselected advanced NSCLC with either primary resistance (cohort 1) or acquired resistance (cohort 2) to prior PD1 axis inhibitor therapy. Nivolumab 3 mg/kg was administered intravenously every 2 weeks, and ipilimumab 1 mg/kg every 6 weeks, and continued until disease progression or treatment limiting toxicity. If > 1 response or prolonged stability (> 24 weeks) using immune related response criteria were observed in the first 10 patients treated on cohort 1, an additional 30 patients would be accrued (simon 2-stage). A total of 10 patients would be accrued to cohort 2 (exploratory cohort). The primary endpoint was objective response rate (ORR) by RECIST v1.1 in cohort 1. Secondary endpoints included, ORR in cohort 2, progression free survival (PFS) and overall survival (OS) in both cohorts. Results: Among 10 patients with primary resistance to PD1 axis inhibitor therapy, no objective responses were observed (8 patients had progressive disease (PD) and 2 patients had unconfirmed stable disease (SD) as best response). Among 10 patients with acquired resistance to PD-1 axis inhibitor therapy, ORR was 10% (1 patient with confirmed complete response, 5 patients with confirmed SD including 4 patients with SD lasting more than 9 months, 3 patients with unconfirmed SD, and 1 patient with PD). Durable clinical benefit (DCB, response or SD for at least 6 months) rate was 50%. Median duration of benefit in the 5 patients with DCB was 11.9 months. Nine of the 10 patients in cohort 2 developed initial resistance to PD-1 axis inhibitor monotherapy (rather than combination chemo-immunotherapy), all received immunotherapy as part of their last line of therapy. The remaining patient developed resistance while on maintenance chemoimmunotherapy after initial response to chemoimmunotherapy; best response to trial therapy in this patient was unconfirmed SD. Median PFS/ OS in cohort 1 were 1.8 months/ 6.8 months, and in cohort 2, 6.7 months/ 31.8 months. Grade 3 treatment-related adverse events (TRAEs) occurred in 4 patients across both cohorts, including colitis (2 pts), diabetes (1 pt), pneumonia (1 pt) and elevated lipase (1 pt). There were no grade 4/5 TRAEs. Two patients discontinued trial therapy due to toxicity (colitis), both in cohort 2. Conclusions: Combination immunotherapy with nivolumab and ipilimumab does not overcome primary resistance to PD1 axis inhibitor therapy; however, can overcome acquired resistance to PD1 axis inhibitor therapy. Translational studies from tumor and serial peripheral blood collections are ongoing. Clinical trial information: NCT03262779 .

A phase II randomized trial of talimogene laherparepvec (T-VEC) oncolytic immunotherapy with or without radiotherapy for patients with cutaneous metastases from solid tumors.

2639 Background: Talimogene laherparepvec (T-VEC) is an oncolytic immunotherapy made from a modified herpes virus expressing granulocyte-macrophage colony-stimulating factor and is FDA approved for the treatment of advanced melanoma. Laboratory studies suggest radiotherapy (RT) may interact with oncolytic immunotherapy to facilitate an immune-mediated anticancer response. We hypothesized that the combination of T-VEC+RT would produce tumor responses in distant (non-irradiated and non-injected) metastases. Methods: A prospective phase II, randomized, Simon two-stage clinical trial of T-VEC with or without RT was conducted with the primary objective of determining if the response rate of the largest non-injected and non-irradiated metastasis was ≥27%. Eligible patients had ≥1 cutaneous metastasis from a solid tumor amenable to T-VEC and RT and 1 measurable metastasis that would not be treated with T-VEC or RT. Using type I and II error probabilities of 10% and 20%, it was calculated that 9 patients would be enrolled in each arm, and if at least 1 of 9 patients subjects exhibited a response, then 6 additional patients would be enrolled in the second stage. Tumor and overall response was assessed using modified World Health Organization (mWHO) and immune related response criteria (irRC). Treatment-emergent and treatment-related adverse events (TEAEs and TRAEs) were characterized using CTCAE v4.0. Results: 19 patients were enrolled and randomized to receive T-VEC alone (n=9) or T-VEC+RT (n=10). One patient in each arm demonstrated a complete response in the largest non-irradiated and non-injected metastasis but progressed in new metastases. The composite response rate in target tumors not injected or irradiated was 13% and 0% in the T-VEC alone and T-VEC+RT arms, respectively. The composite response rate in target tumors treated with T-VEC alone or T-VEC+RT was 7% and 22%, respectively. Because no patient exhibited an overall mWHO or irRC defined response and due to slow accrual, the trial was closed after the first stage of enrollment despite meeting the prespecified response rate to continue enrollment in the second stage. Grade 3-4 TEAEs and TRAEs occurred in 9 and 2 patients, with similar frequencies between study arms. The most common AE was fever and occurred in 47% of patients. Peripheral blood-based immunologic analyses will be presented. Conclusions: The response rate in the largest non-injected or non-irradiated metastasis following T-VEC with or without RT given to a cutaneous metastasis from solid tumor could be ≥27% but was not determined in this trial due to premature closure, in part due to slow accrual rate and no observed mWHO defined overall responses. Cutaneous metastases responded more often after TVEC+RT than T-VEC alone, but the response in non-injected and non-irradiated tumors was more frequent after T-VEC alone. Clinical trial information: NCT02819843 .

A phase Ib study of endogenous T cell therapy using SLC45A2-specific CD8 T cells for patients with metastatic uveal melanoma.

9588 Background: Overall survival (OS) for patients (pts) with advanced uveal melanoma (UM) is poor compared with outcomes in cutaneous melanoma. Roughly half of all pts with UM will develop distant metastatic disease despite effective treatment of the primary tumor. Antigen-specific endogenous T cells (ETC) can be expanded and infused successfully in pts with many different types of cancer. Our group has identified epitopes of SLC45A2, a melanosomal transport protein, which are highly expressed in UM and are present at low levels in normal melanocytes. In vitro, we showed that cytotoxic T cells against SLC45A2 were able to kill HLA-matched UM cell lines. In vivo, we hypothesize that infused ETC can traffic to tumor sites. Methods: Between 6/2017 and 12/2022, we conducted a single-center, IRB-approved, first-in-human phase 1b dose escalation study of ETC targeting SLC45A2 in pts with metastatic UM (NCT03068624). Eligible pts with metastatic UM who express HLA-A*02:01 or A*24:02 underwent apheresis to collect peripheral T cells which were then selected and expanded (Turnstile 1). For Turnstile 2, conditioning with low-dose cyclophosphamide (300 mg/m2) occurred on Day -2. For pts in the radiation cohort, radiation occurred between Day -7 and Day -1. Infusion of ETC was done via hepatic arterial or central venous catheter on Day 0 followed by low dose subcutaneous interleukin-2 (IL-2) twice daily for 14 days +/- ipilimumab. The study utilized a 3+3 design with a starting dose level of 3.3 x 109 cells/m2 of ETC alone. The primary objective was to evaluate the safety and tolerability of infusing ETC targeting SLC45A2. Secondary objectives were to evaluate the in vivo persistence and anti-tumor efficacy of this regimen. Results: With a median age of 58 years (30-77), 34 pts were enrolled, 16 (47%) men and 18 (53%) women. 33 (97%) pts underwent apheresis and 11 (32%) received infusion of ETC. One dose limiting toxicity (DLT) thought to be unrelated to treatment or underlying cancer (cardiac disorder Grade 5) occurred at the starting dose level with no additional DLTs. The maximum tolerated dose was established as 1 x 1010 cells/m2. The most common treatment-related grade 3 and 4 toxicities were lymphocyte count decrease 9 (82%), hyponatremia 1 (9%), and hypophosphatemia 1 (9%). Per immune-related response criteria (irRC), 4 (36%) pts had stable disease (SD), 6 (55%) had progression of disease (PD), and 1 (9%) was not evaluable for best response. Median overall survival (OS) was 8.9 weeks (wks). OS was 91% at 4 wks, 55% at 8 wks and 46% at 13 wks. Median progression-free survival was 5.9 wks. In the 4 patients with stable disease, the median duration of SD was 5.7 months. Conclusions: ETC targeting SLC45A2 is safe and well-tolerated in pts with metastatic UM. Further analyses are underway to evaluate T cell trafficking and persistence. Clinical trial information: NCT03068624 .

Long-term outcome for patients with advanced non‒small-cell lung cancer treated by autologous cytokine-induced killer (CIK) cell immunotherapy in combination with sintilimab plus chemotherapy: NSCLC-CCICC-002.

9096 Background: Autologous cytokine-induced killer (CIK) cell immunotherapy in combination with Sintilimab demonstrated robust antitumor activity and safety in the phase Ib CCICC-002 study (NCT03987867) of Non‒Small-Cell Lung Cancer. Long-term outcomes in patients are reported herein. Methods: Systemic therapy naïve patients received platinum-based doublet chemotherapy, Sintilimab (PD1 inhibiter), and CIK cells every 3 weeks for 4 cycles, then maintenance treatment with Sintilimab in squamous and with Sintilimab plus pemetrexed in non-squamous NSCLC until disease progression or unacceptable toxicity or two years. Kaplan-Meier estimates of overall survival (OS) and progression-free survival (PFS) were calculated. OS and PFS were based on immune-related response criteria by investigator assessment (data cut-off, January 31, 2023). Results: From May 2019 to Jan 2021, CCICC-002 enrolled 33 patients（19 squamous, 14 non-squamous NCSLC; 1 patient was excluded because the second biopsy revealed EGFR mutation) aged 46-73 years with median follow-up was 31.4 months (range, 7.6-44.4 months). Estimated 3-year OS was 51.8% in all patients; median OS was not reached (95% CI, 26.6 months-not reached) in all patients. In subgroups, median OS was 27.6 months (95% CI, 13.4 months-not reached) in squamous NCSLC and not reached (95% CI, 29.9 months-not reached) in non-squamous NCSLC, respectively. Median OS was not reached (95% CI, 27.6 months-not reached) in PD-L1 positive patients and 28.3 months (95% CI, 15.6 months-not reached) in PD-L1 negative patients, respectively. Estimated 3-year PFS rate was 27.5% and median PFS was 17.9 months (95% CI, 8.2-26.5 months) in all patients. Median PFS was 17.3 months (95% CI, 5.0-24.0 months) in squamous NCSLC and 22.4 months (95% CI, 5.7 months-not reached) in non-squamous NCSLC, respectively. Median response duration was 18.7 months (95% CI, 10.1-27.6 months). 30.3% of patients were ongoing at data cut-off, and the longest response was ongoing at 41.3 months. 1 of the 5 CMR (complete metabolic response by PET-CT) patients experienced disease progression during observation. Treatment-related AEs (TRAEs) occurred in 94.0% of patients and resulted in study discontinuation in 7.8%, and 15.2% experienced grade 3/4 TRAE. Conclusions: This long-term analysis of CCICC-002 represents the longest follow-up for CIK to date and confirms the durable antitumor activity and tolerability of CIK cells therapy in combination with Sintilimab plus chemotherapy in advanced NCSLC. Further studies are warranted to confirm these preliminary results. Clinical trial information: NCT03987867 .

Tumor infiltrating lymphocyte (TIL) harvest and ex vivo expansion from primary and metastatic (met) uveal melanoma (UM) tumors.

9513 Background: Adoptively transferred autologous cell therapy using tumor-infiltrating lymphocytes (TIL) is an emerging treatment for met melanoma. Responses have been seen in patients (pts) with checkpoint inhibitor-naïve and -refractory cutaneous melanoma. UM represents a disease subtype that is traditionally less responsive to immune checkpoint blockade (ICB). Preliminary studies have shown clinical utility of TIL in UM pts. However, data describing the success rates of TIL harvest and ex vivo expansion of cells from primary and met UM tumors, and of the treatment of pts with met UM, is limited. Methods: Between 2004 and 2019, we conducted a single-center IRB-approved trial (NCT NCT00338377) for TIL harvest in pts age 18 and older with documented met melanoma, including UM pts. The protocol was amended to allow harvest of primary UM tumors in 2015 if the pt was dispositioned for enucleation as primary treatment. Results: A total of 96 UM pts underwent TIL harvest; 9 underwent treatment with TIL. Median age was 54 years (range: 28 – 86); 56% of the pts were male; 78% were Caucasian, 9% Hispanic, and 13% unknown ethnicity. Overall successful ex vivo expansion of TIL occurred in 34.8% (32/92) of UM tumors in typical tumor fragment culture with IL-2 (TIL 1.0), with higher rates observed with UM mets (29/65; 44.6%) than UM primary tumors (3/27; 11.1%). Better results were observed with a culture method (TIL 3.0) that includes agonistic stimulation of CD3 and 41BB, with 96.8% (30/31 tumors). Expansion using this new method was successful in 9/10 primary UM tumors and 21/21 UM mets. Average number of days in culture for successful initial ex vivo expansion was 33.0 days for TIL 1.0 and 17.9 days for TIL 3.0 ( p-value<0.0001). Overall, the average number of TIL expanded from culture and cryopreserved for clinical use was 130.4 million for TIL 1.0 (range: 34-460) and 326.2 million for TIL 3.0 (range 102-760) ( p-value<0.0001). Nine met UM pts received treatment with up to 150 x 109 post-Rapid Expansion Protocol (REP) TIL (5 TIL 1.0, 4 TIL 3.0). Median age was 53, 44% were male, and all had active liver mets with a median of 3 lines of prior treatment for advanced disease. 8 of the TIL products were from UM mets (4 soft tissue, 3 liver, 1 combination of soft tissue and liver tumors), and 1 was from primary UM tumor, for which TIL could only be expanded with TIL 3.0. Best overall response rate per immune-related response criteria was 22% partial response (PR, duration of response was 22.1 months and 16.5 months), 44% stable disease (SD), and 33% progression of disease (PD) for a disease control rate of 66% (PR + SD). Both responding pts had TIL harvests from mets and had previously progressed on ICB, one was treated with TIL 3.0. Conclusions: TIL harvest and successful ex vivo expansion of cells is possible from both primary and met UM with TIL 3.0 culture method and can be therapeutically effective. Clinical trial information: NCT00338377 .

Lefitolimod (TLR agonist) and ipilimumab in patients with advanced solid tumors: A phase I trial.

2564 Background: The TLR-9 agonist lefitolimod (MGN1703) significantly increases the Th1 response in pre-clinical models and has demonstrated antitumor activity in early phase clinical trials. This trial assessed the safety and preliminary efficacy of the rational combination of lefitolimod with ipilimumab in patients (pts) with advanced solid tumors. Methods: This was a single-center, open-label, investigator-initiated, dose-finding, and expansion Phase I trial (ClinicalTrials.gov no. NCT0266877). Key inclusion criteria were histologically confirmed advanced solid tumor, ECOG performance status ≤ 2; age ≥ 18 years. Patients (pts) were enrolled at escalating doses of lefitolimod (15-120 mg/kg), subcutaneously (SC) administered weekly and a fixed dose of ipilimumab 3 mg/kg in a 3-week cycle. For the expansion cohort, lefitolimod was administered intratumorally (IT) at 15 mg weekly. The primary endpoint was safety and tolerability according to CTCAE v4.0, dose-limiting toxicity (DLT) and maximum tolerated dose (MTD)/recommended Phase II dose (RP2D) for the lefitolimod in this combination. The secondary endpoint was efficacy, evaluated according to Immune-Related Response Criteria (irRC). Exploratory endpoints included changes in the intra-tumoral T-cell microenvironment in pre- and post- treatment tumor biopsies and the correlation of immune biomarkers with response. Results: From March 2017 to February 2020, 28 pts were enrolled. Median age was 56 years (range: 19-92). Median prior lines of therapy was 4 (range: 0-12). Pts 1-4 received lefitolimod 15 mg SC, pts 5-8 received lefitolimod 30 mg SC, pts 9-12 received lefitolimod 60 mg SC, pts 13-19 received lefitolimod 120 mg SC, and pts 20-28 received lefitolimod 15 mg IT. Eleven pts had at least one treatment-related AE (TRAE). The most common TRAE was skin rash (n=4, 14.2%), followed by fatigue (n=3, 10.7%) and pruritis (n=2, 7.1%). There were no grade 4 or 5 AEs, none of the pts required dose reduction, and there was no discontinuation of treatment due to AEs. DLT and MTD were not reached and the RP2D was established as lefitolimod SC 120 mg weekly with ipilimumab 3mg/Kg every 3 weeks. Of the 28 pts, 8 pts had stable disease as best response. 7 pts could not be evaluated by irRC due to clinical progression before restaging, non-measurable lesions and withdrawal of consent. Paired biopsy samples were analyzed by flow cytometry. Pro-inflammatory immune conditioning of the tumor microenvironment by the combination of the TLR9 agonist MGN1703 in combination with ipilimumab showed increases in intra-tumoral CD8 T cell frequency, memory CD8 phenotype (CD45RO+) and proliferation (Ki67+). Conclusions: The combination of high subcutaneous doses or intra-tumoral administration of lefitolimod in combination with ipilimumab is safe and well tolerated in patients with advanced cancers, with preliminary antitumor activity observed. Clinical trial information: NCT0266877 .

A phase 1, first-in-child, multicenter study to evaluate the safety and efficacy of the oncolytic herpes virus talimogene laherparepvec in pediatric patients with advanced solid tumors.

The survival rates for pediatric patients with relapsed and refractory tumors are poor. Successful treatment strategies are currently lacking and there remains an unmet need for novel therapies for these patients. We report here the results of a phase 1 study of talimogene laherparepvec (T-VEC) and explore the safety of this oncolytic immunotherapy for the treatment of pediatric patients with advanced non-central nervous system tumors. T-VEC was delivered by intralesional injection at 106 plaque-forming units (PFU)/ml on the first day, followed by 108 PFU/ml on the first day of week 4 and every 2 weeks thereafter. The primary objective was to evaluate the safety and tolerability as assessed by the incidence of dose-limiting toxicities (DLTs). Secondary objectives included efficacy indicated by response and survival per modified immune-related response criteria simulating the Response Evaluation Criteria in Solid Tumors (irRC-RECIST). Fifteen patients were enrolled into two cohorts based on age: cohort A1 (n = 13) 12 to ≤21 years old (soft-tissue sarcoma, n = 7; bone sarcoma, n = 3; neuroblastoma, n = 1; nasopharyngeal carcinoma, n = 1; and melanoma, n = 1) and cohort B1 (n = 2) 2 to <12 years old (melanoma, n = 2). Overall, patients received treatment for a median (range) of 5.1 (0.1, 39.4) weeks. No DLTs were observed during the evaluation period. All patients experienced at least one treatment-emergent adverse event (TEAE), and 53.3% of patients reported grade ≥3 TEAEs. Overall, 86.7% of patients reported treatment-related TEAEs. No complete or partial responses were observed, and three patients (20%) overall exhibited stable disease as the best response. T-VEC was tolerable as assessed by the observation of no DLTs. The safety data were consistent with the patients' underlying cancer and the known safety profile of T-VEC from studies in the adult population. No objective responses were observed. ClinicalTrials.gov: NCT02756845. https://clinicaltrials.gov/ct2/show/NCT02756845.

Assessment of Response to Immunotherapy in Patients with Hodgkin Lymphoma: Towards Quantifying Changes in Tumor Burden Using FDG-PET/CT.

Immune checkpoint inhibitors are currently the standard of care for many advanced solid tumors, and they have been recently approved for the treatment of relapsed/refractory Hodgkin lymphoma and primary mediastinal B cell lymphoma. Assessments of the response to immunotherapy may be complicated by the occurrence of the flare/pseudoprogression phenomenon, consisting of initial tumor enlargement and even the appearance of new lesions, followed by a response, which may initially be indistinguishable from true progression. There have been efforts to characterize and capture the new patterns of response observed during immunotherapy, namely, pseudoprogression and delayed response, and several immune-related response criteria have been proposed. Confirming progression on a subsequent scan and measuring the total tumor burden are both common in immune-related criteria. Due to the peculiarity of hematologic malignancies, lymphoma-specific immune-related criteria have been developed (LYRIC), and they have been evaluated in research studies in comparison to the Lugano Classification. In this review work, we illustrate the evolution of the response criteria in lymphomas from the first CT-based criteria to the development of the PET-based Lugano Classification, further refined to take into account the flare phenomenon encountered during immunotherapy. We also describe the additional contribution of PET-derived volumetric parameters to the interpretation of responses during immunotherapy.

Immune checkpoint inhibitors: Assessment of the performance and the agreement of iRECIST, irRC, and irRECIST.

Immunotherapy has become more widely accepted and used by medical oncologists. Radiologists face challenges in assessing tumor response and becoming more involved in the management of treatment. We aimed to assess the agreement between immune-related response criteria (irRC), immune-related RECIST (irRECIST), and immune RECIST (iRECIST) to correlate the response measured by them with overall survival (OS), and to determine the confirmation rate of progressive disease (PD). A total of 43 patients (28 men, 15 women; average age = 54.6 ± 15.7 years) treated with immunotherapy were included in this study. Pairwise agreements between iRECIST, irRC, and irRECIST were calculated using Cohen's kappa statistics. The correlation of the criteria-based response and OS was evaluated using the Kaplan-Meier method and log-rank test. A confirmation rate with 95% confidence intervals (CI) was calculated in patients with PD. The kappa values between iRECIST and irRC, iRECIST and irRECIST, and irRC and irRECIST were 0.961 (almost perfect; P < 0.001), 0.961 (almost perfect; P < 0.001), and 0.922 (almost perfect; P < 0.001), respectively. The Kaplan-Meier method and log-rank test showed for each criterion a statistically significant correlation with OS (P < 0.05). The confirmation rates of PD for irRC, irRECIST, and iRECIST were 95% (19/20; 95% CI = 76.4-99.1%), 90% (18/20; 95% CI = 69.9-97.2%), and 90.5% (19/21; 95% CI = 71.1-97.4%), respectively. There was an almost perfect and statistically significant agreement between iRECIST, irRC, and irRECIST. The measurements performed with them significantly correlated with the OS; their confirmation rates were similar. iRECIST and irRECIST might be favored over irRC because of their relative ease of use.

A phase II trial of pembrolizumab combined with platinum-based chemotherapy as first-line systemic therapy in advanced penile cancer: HERCULES (LACOG 0218) trial.

TPS14 Background: Penile squamous cell carcinoma (PSCC) is an uncommon malignancy which accounts for 2,300 new cases and 400 deaths annually worldwide. However, in low-income countries from South America, Asia and Africa, incidence corresponds to 10-20% of all malignancies in men. Approximately 4% of PSCC patients present with metastatic disease at diagnosis. Also, even if diagnosed in early stages (localized disease), around 30% of patients will recur. No improvements have been achieved over the last three decades in platinum-based chemotherapy, which remains the standard-of-care; objective response rate (ORR), median progression-free survival (PFS) and overall survival (OS) are currently at 20-30%, 3-4 months and 7-15 months, respectively. HPV16 is the most important known risk factor for PSCC. Favorable results have been achieved with Pembrolizumab in other HPV-associated cancers, such as cervical and oropharyngeal cancer. HERCULES (LACOG 0218) aims to evaluate the efficacy of pembrolizumab combined with platinum-based chemotherapy as first-line treatment in advanced PSCC. Methods: HERCULES is a phase 2, single-arm, multicentric trial evaluating patients with histologically proven PSCC and metastatic disease (de novo or recurrent); or recurrent locally advanced disease not amenable to curative-intent therapy; or TanyN3M0 or T4NanyM0 (stage IV – AJCC 8th ed) not amenable to curative-intent therapy. Additional inclusion criteria were ECOG PS 0–1; measurable disease by RECIST 1.1; no prior systemic therapy for recurrent or metastatic disease (however, patients progressing after 12 months of neo/adjuvant chemotherapy completion are allowed). The primary endpoint is ORR up to week 24. Secondary endpoints are OS, PFS, clinical benefit rate, immune related response criteria, quality of life, safety, and predictive biomarkers of response/survival. Eligible subjects receive 5-FU 1000mg/m²/day IV D1-D4, cisplatin 70mg/m² or carboplatin AUC 5 IV D1 plus pembrolizumab 200mg IV D1 at each 3-week (Q3W) dosing cycle for 6 cycles, followed by Pembrolizumab 200mg IV Q3W maintenance. Patients without disease progression are allowed to continue pembrolizumab monotherapy until completing 34 cycles, disease progression or unacceptable toxicity, whichever comes first. Tumor evaluations are performed every 6 weeks until week 24. Sample size was calculated as 33 patients to detect an increase in ORR from 20% to 40% up to week 24 with 78.5% power and considering 10% drop-out. From Aug 2020 to Jul 2022, 33 patients were enrolled in 11 Brazilian research sites. Results are expected in 2023. NCT04224740. Clinical trial information: NCT04224740 .

Intratumoral oncolytic virus V937 plus ipilimumab in patients with advanced melanoma: the phase 1b MITCI study

BackgroundIntratumoral administration of V937, a bioselected, genetically unmodified coxsackievirus A21, has previously demonstrated antitumor activity in patients with advanced melanoma as monotherapy and in combination with the programmed cell death...

Tumor response assessment on imaging following immunotherapy.

In recent years, various systemic immunotherapies have been developed for cancer treatment, such as monoclonal antibodies (mABs) directed against immune checkpoints (immune checkpoint inhibitors, ICIs), oncolytic viruses, cytokines, cancer vaccines, and adoptive cell transfer. While being estimated to be eligible in 38.5% of patients with metastatic solid or hematological tumors, ICIs, in particular, demonstrate durable disease control across many oncologic diseases (e.g., in melanoma, lung, bladder, renal, head, and neck cancers) and overall survival benefits. Due to their unique mechanisms of action based on T-cell activation, response to immunotherapies is characterized by different patterns, such as progression prior to treatment response (pseudoprogression), hyperprogression, and dissociated responses following treatment. Because these features are not encountered in the Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1), which is the standard for response assessment in oncology, new criteria were defined for immunotherapies. The most important changes in these new morphologic criteria are, firstly, the requirement for confirmatory imaging examinations in case of progression, and secondly, the appearance of new lesions is not necessarily considered a progressive disease. Until today, five morphologic (immune-related response criteria (irRC), immune-related RECIST (irRECIST), immune RECIST (iRECIST), immune-modified RECIST (imRECIST), and intra-tumoral RECIST (itRECIST)) criteria have been developed to accurately assess changes in target lesion sizes, taking into account the specific response patterns after immunotherapy. In addition to morphologic response criteria, 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography (18F-FDG-PET/CT) is a promising option for metabolic response assessment and four metabolic criteria are used (PET/CT Criteria for Early Prediction of Response to Immune Checkpoint Inhibitor Therapy (PECRIT), PET Response Evaluation Criteria for Immunotherapy (PERCIMT), immunotherapy-modified PET Response Criteria in Solid Tumors (imPERCIST5), and immune PERCIST (iPERCIST)). Besides, there is evidence that parameters on 18F-FDG-PET/CT, such as the standardized uptake value (SUV)max and several radiotracers, e.g., directed against PD-L1, may be potential imaging biomarkers of response. Moreover, the emerge of human intratumoral immunotherapy (HIT-IT), characterized by the direct injection of immunostimulatory agents into a tumor lesion, has given new importance to imaging assessment. This article reviews the specific imaging patterns of tumor response and progression and available imaging response criteria following immunotherapy.

Predictors of Response to Salvage High-Dose plus Low-Dose Radiation in Checkpoint-Inhibitor Resistant Patients

<h3>Purpose/Objective(s)</h3> Patients (pts) with immune checkpoint inhibitor (ICI)-resistant advanced cancer have poor outcomes and limited alternative treatment options. High-dose radiation therapy (HD-RT) can augment local and systemic ICI effects and lead to tumor regression outside of the treatment field (abscopal effect). Low-dose RT (LD-RT) to secondary sites may further enhance responses by modulating the stroma and facilitating immune cell infiltration. Prior studies suggest that high BED regimens may better stimulate antitumor immune responses than lower BED regimens. We explored BED and baseline pt factors as predictors of response to salvage HD-RT plus LD-RT in a <i>post hoc</i> analysis of an ongoing phase II trial. <h3>Materials/Methods</h3> We included 56 (of 60) enrolled pts with follow up imaging in our analysis. All had metastatic solid tumors that progressed on ICI. Study treatment consisted of HD-RT to 1-2 sites plus LD-RT to 1+ additional sites. HD-RT regimens included conventional RT, comprised of 20-60 Gy in 4-5 fractions (fx), or stereotactic body RT (SBRT), comprised of 27-36 Gy in 3 fx, 50 Gy in 4 fx, or 60-70 Gy in 10 fx. LD-RT consisted of 1-10 Gy total doses given in 0.5-2 Gy fxs, with 7 Gy/5 fx being the most frequent. We evaluated relationships between pt responses (disease control at 4mo post-RT, DC; overall objective response, OR; time-to-progression, TTP) and patient- and treatment-related factors with logistic and Cox proportional hazard models. PFS and response outcomes were then assessed after stratifying by HD-RT BED₁₀ (BED>100 vs BED<100). <h3>Results</h3> Of 56 pts, 20 received HD-RT with BED >100 (range 106-119) and 36 with BED <100 (range 28-96). DC (SD or PR/CR per immune related response criteria, irRC) was achieved in 28/54 pts (52%; 2 pts not evaluable for response). OR (PR/CR) occurred in 15/54 pts (28%). On UVA, HD-RT BED₁₀ was predictive of both DC (OR 1.02, P = 0.03) and OR (OR 1.03, P = 0.008). Other factors, including age, gender, histology, fx count, baseline absolute lymphocyte count (bALC), and metastatic burden (MB) did not affect DC or OR. Stratifying by BED₁₀, median PFS was greater for the BED >100 cohort than BED <100 cohort (6.5mo vs 2.5mo, HR 0.43, P = 0.009), as were DCR (78% vs 39%, OR 5.5, P = 0.01) and ORR (OR 61% vs 11%, OR 12.6, P < 0.001). Cox multivariable analysis indicated that BED >100 (HR 0.27, P < 0.001), MB (HR 1.22, P = 0.001) and bALC (HR 0.43, P < 0.001) were independent predictors of TTP. However, when stratified by IO-class (PD1/PDL1 vs CTLA-4/combo) and histology (NSCLC vs other), only BED remained consistently significant. <h3>Conclusion</h3> Salvage HD-RT plus LD-RT is a unique therapeutic approach that can re-induce disease control after ICI progression. HD-RT regimens with a higher BED₁₀ – optimally >100 – will likely provide the greatest chance of treatment success with this strategy. Larger randomized trials are needed to further explore the role of salvage RT in ICI resistance.

Predictors of Systemic Responses Induced by Salvage Radiation after Progression on Immunotherapy

<h3>Purpose/Objective(s)</h3> Radiation can induce systemic immune responses and tumor regression outside of the treatment field, a phenomenon known as the abscopal effect. Salvage high dose radiation (HD-RT) may reinvigorate antitumor immunity and re-induce disease control in patients (pts) with advanced cancer who have progressed on immune checkpoint inhibition (ICI). Prior studies suggest that BED ≥ 100 is optimal for disease control and may produce superior antitumor immune responses than lower BED regimens. We explored BED and pt factors as predictors of response to salvage HD-RT in a <i>post hoc</i> analysis of an ongoing phase II immunoradiation trial. <h3>Materials/Methods</h3> We included 50 enrolled trial pts in our analysis. All had metastatic solid tumors that progressed on ICI. Study treatment consisted of HD-RT to 1-2 sites, leaving at least 1 site untreated to monitor for abscopal response. Regimens included conventional RT, comprised of 20-30 Gy in 5 fractions (fx) or 45-52.5 Gy in 15 fx, or stereotactic body RT (SBRT), comprised of 24 Gy in 3 fx, 50 Gy in 4 fx, or 63-70 Gy in 9-10 fx. We evaluated relationships between response (disease control at 4mo post-RT, DC; overall objective response, OR; abscopal response, AR; time-to-progression, TTP) and patient- and treatment-related factors with logistic regression and Cox proportional hazard models. PFS and response outcomes were then assessed after stratifying by HD-RT BED₁₀ (BED>100 vs BED<100). <h3>Results</h3> Systemic disease control rate (DCR; SD or PR/CR per immune related response criteria, irRC) was 45% (24/49 pts; 1 pt not evaluable for response). OR (PR/CR) were observed in 8/49 pts (16%). AR (lesion-level CR/PR) were observed in 14/49 pts (29%). On multivariable analysis, HD-RT BED₁₀ (OR 111.9 P = 0.001) and baseline absolute lymphocyte count (bALC; OR 5.4 P = 0.02) predicted probability of DC, while gender, age, metastatic burden (MB), and fx count did not. Of 50 pts, 18 received HD-RT with BED >100 (range 107-119) and 32 with BED <100 (range 28-96). Stratifying by BED, median PFS was greater for the BED >100 cohort than BED <100 (8mo vs 2mo HR 0.45 P = 0.003), and DCR was 83% for BED >100 vs 28% for BED <100 (RR 2.96 P < 0.001). Although not statistically significant, ORR was also greater in BED >100 vs BED <100 (24% vs 12.5% P = 0.4), as was ARR (41% vs 22% P = 0.2). On Cox multivariable analysis, BED >100 (HR 0.27 P < 0.001), MB (HR 1.22 P < 0.001), and bALC (HR 0.43 P < 0.001) were independent predictors of TTP. Adjusting for IO class (PD1/PDL1 vs CTLA-4/combo) and histology (NSCLC vs other), each of these factors remained significant. <h3>Conclusion</h3> Salvage HD-RT after systemic progression on ICI may be a valid treatment option that is most likely to benefit pts with lower disease burden and stable ALC. RT regimens utilizing SBRT with BED₁₀ >100 will likely provide improved outcomes compared to lower BED regimens. Larger trials are indicated to validate optimal regimens and cohorts for this strategy.

Pembrolizumab, radiotherapy, and an immunomodulatory five-drug cocktail in pretreated patients with persistent, recurrent, or metastatic cervical or endometrial carcinoma: Results of the phase II PRIMMO study

A phase II study (PRIMMO) of patients with pretreated persistent/recurrent/metastatic cervical or endometrial cancer is presented. Patients received an immunomodulatory five-drug cocktail (IDC) consisting of low-dose cyclophosphamide, aspirin, lansoprazole, vitamin D, and curcumin starting 2 weeks before radioimmunotherapy. Pembrolizumab was administered three-weekly from day 15 onwards; one of the tumor lesions was irradiated (8Gyx3) on days 15, 17, and 19. The primary endpoint was the objective response rate per immune-related response criteria (irORR) at week 26 (a lower bound of the 90% confidence interval [CI] of > 10% was considered efficacious). The prespecified 43 patients (cervical, n = 18; endometrial, n = 25) were enrolled. The irORR was 11.1% (90% CI 2.0–31.0) in cervical cancer and 12.0% (90% CI 3.4–28.2) in endometrial cancer. Median duration of response was not reached in both cohorts. Median interval-censored progression-free survival was 4.1 weeks (95% CI 4.1–25.7) in cervical cancer and 3.6 weeks (95% CI 3.6–15.4) in endometrial cancer; median overall survival was 39.6 weeks (95% CI 15.0–67.0) and 37.4 weeks (95% CI 19.0–50.3), respectively. Grade ≥ 3 treatment-related adverse events were reported in 10 (55.6%) cervical cancer patients and 9 (36.0%) endometrial cancer patients. Health-related quality of life was generally stable over time. Responders had a significantly higher proportion of peripheral T cells when compared to nonresponders (p = 0.013). In conclusion, PRIMMO did not meet its primary objective in both cohorts; pembrolizumab, radiotherapy, and an IDC had modest but durable antitumor activity with acceptable but not negligible toxicity.Trial registration ClinicalTrials.gov (identifier NCT03192059) and EudraCT Registry (number 2016-001569-97).

Abstract 463: Highly accurate machine learning assessment of immune-related pathologic response criteria (irPRC) scoring in patients with non-small cell lung carcinoma (NSCLC) treated with neoadjuvant anti-PD-1-based therapies

Abstract Pathological complete response (no residual viable tumor, RVT) and/or major pathologic response (≤10% RVT) are now primary or secondary endpoints for a large proportion of clinical trials studying neoadjuvant immunotherapeutic regimens. We previously developed a scoring system for assessing pathologic response after immunotherapy, termed irPRC (Cottrell et al. Ann Oncol 2018). By these criteria, %RVT is assessed by dividing RVT by the sum of the surface area on the slide composed of RVT + necrosis + regression bed– the latter feature is where the tumor used to be and is characterized by fibroinflammatory stroma that is distinct from tumoral stroma. We have previously reported high inter-observer reproducibility for pathologic response assessment following immunotherapy. However, these assessments involve performing evaluations that are currently outside the scope of routine surgical pathology training and may be time-consuming. To date, these assessments have primarily been performed by academic pathologists who have seen the largest number of these cases as a part of clinical trials. A machine learning (ML)-powered assessment of irPRC would allow for faster, standardized evaluation and expanded access to patients treated outside of large academic centers. We trained a supervised convolutional neural network to assess pathologic response using irPRC on n=92 H&amp;E-stained slides from patients with advanced, resectable NSCLC treated with neoadjuvant anti-PD-1 +/- anti-CTLA-4 at a single institution. The ML algorithm was trained based on ground-truth manual annotations by pathologists on whole slide digital scans and tested using leave-one-out cross validation. Each of ~830,000 image tiles was classified into one of four classes: tumor, necrosis, immune-mediated regression, or background lung tissue. Receiver operating curves showed that the algorithm exhibited high accuracy for predicting the various tissue classes with an area under the curve of 0.95, 0.96, 0.90, and 0.90 for the four classes, respectively. %RVT was calculated by dividing the surface area of RVT by total tumor bed surface area (RVT + necrosis + regression). There was a strong positive correlation between the machine assessed RVT and the human assessed RVT at both the slide level and case level (aggregate %RVT based on surface area from all slides for a given patient), Pearson’s r=0.95 and r=0.99, respectively. Here, we demonstrate that a ML algorithm performs as well as an experienced pathologist assessment in scoring pathologic response. These findings will need to be validated in larger studies. Additionally, the association of pathologic response with longer term patient outcomes will be evaluated as survival data matures to determine whether pathologic response is a robust surrogate of survival. Citation Format: Julie E. Stein, Vinay Pulim, Tricia R. Cottrell, Patrick M. Forde, Janis M. Taube. Highly accurate machine learning assessment of immune-related pathologic response criteria (irPRC) scoring in patients with non-small cell lung carcinoma (NSCLC) treated with neoadjuvant anti-PD-1-based therapies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 463.

Neoadjuvant nivolumab (NIVO) + platinum-doublet chemotherapy (chemo) versus chemo for resectable (IB–IIIA) non-small cell lung cancer (NSCLC): Association of pathological regression with event-free survival (EFS) in CheckMate 816.

LBA8511 Background: Several studies have shown an association of pathological response, a common efficacy endpoint in neoadjuvant therapy trials, with survival for chemo in various cancers including resectable NSCLC. However, the association between pathological complete response (pCR) and survival as well as the degree of pathological regression that may be predictive of EFS for neoadjuvant immunotherapy has not been rigorously studied. CheckMate 816 (NCT02998528), a randomized phase 3 study of neoadjuvant NIVO + chemo vs chemo in resectable NSCLC, met both of its primary endpoints with a statistically significant and clinically meaningful improvement in EFS and pCR. Here, we report a post hoc analysis from CheckMate 816, characterizing the association between pathological regression and EFS. Methods: Adults with resectable NSCLC were randomized to NIVO 360 mg + platinum-doublet chemo Q3W or chemo alone Q3W for 3 cycles. Primary endpoints were EFS and pCR (0% residual viable tumor [RVT] in the primary tumor [PT] and lymph nodes [LN] based on immune-related pathological response criteria), both assessed by blinded independent review. Major pathological response (MPR; ≤10% RVT in the PT and LN) was a secondary endpoint. In this post hoc analysis, EFS was assessed based on depth of pathological regression (measured by %RVT) in the PT only. Also, a time-dependent receiver operating characteristic curve analysis assessed the predictive ability of %RVT (PT only) for EFS outcome at 2 years, using area under the curve (AUC) to summarize the overall diagnostic accuracy (0.5 = random chance; 1 = perfect accuracy). Results: Baseline characteristics in patients (pts) with pathologically evaluable samples were well balanced between the NIVO + chemo and chemo arms, similar to the overall population. In both treatment arms, EFS (minimum follow-up, 21 months) was improved in pts with vs without pCR or MPR (Table). %RVT appeared to be predictive of EFS at 2 years for NIVO + chemo (AUC = 0.74) but an association was not clear for chemo (AUC = 0.54). 2-year EFS rates for NIVO + chemo were 90%, 60%, 57%, and 39% for pts with 0–5%, &gt;5–30%, &gt;30–80%, and &gt;80% RVT, respectively. Conclusions: In CheckMate 816, pathological response (pCR and MPR) in the PT was associated with improved EFS with neoadjuvant NIVO + chemo. Additionally, depth of pathological regression appeared to be predictive of improved EFS. Clinical trial information: NCT02998528. [Table: see text]

New Challenges in Evaluating Outcomes after Immunotherapy in Recurrent and/or Metastatic Head and Neck Squamous Cell Carcinoma.

In many recurrent and/or metastatic cancers, the advent of immunotherapy opens up new scenarios of treatment response, with new phenomena, such as pseudoprogression and hyperprogression. Because of this, different immune-related response criteria have been developed, and new therapeutic strategies adopted, such as treatment beyond progression. Moreover, the role of progression-free survival as a surrogate has been questioned, and new surrogate endpoint hypotheses have arisen. A proper understanding of radiological imaging, an assessment of the biological events triggered by therapy, and the clinical evolution of the lesions and of the patient performance status are all factors that should be considered to guide the oncologist’s treatment choice. The primary aim of this article is to discuss how all these concepts apply to recurrent/metastatic head and neck squamous cell carcinoma patients when treated with immunotherapy.

A phase II multi-arm study to test the efficacy of oleclumab and durvalumab in specific sarcoma subtypes.

TPS11594 Background: Anti-PD 1/PD-L1 blockade alone or in combination with anti-CTLA4 have yielded suboptimal results in most sarcoma subtypes. CD73, an ectonucleotidase, catalyzes the rate-limiting step for adenosine production in the extracellular space, which then aids tumors in evading immune recognition and destruction. Oleclumab, a monoclonal antibody (mAb) selectively binds and inhibits the activity of CD73, and preclinical data suggests additive activity with durvalumab, a mAb that blocks PD-L1. We designed a trial combining oleclumab and durvalumab in certain sarcoma subtypes, selected based on modest activity with anti-PDL-1 and intense staining with CD73 in the tumor microenvironment. Methods: This phase 2 study (NCT04668300) is enrolling patients with age ≥18 years with recurrent/metastatic angiosarcoma (cohort 1) or dedifferentiated liposarcoma (DLPS) (cohort 2) and ≥12 years with recurrent/metastatic osteosarcoma (cohort 3), who have received at least one prior systemic therapy but are checkpoint inhibitor naïve and have measurable disease. Each treatment cycle is 28 days with oleclumab administered at 3000 mg i.v. every 2 weeks x 5 doses, and then every 4 weeks and durvalumab administered at 1500 mg i.v every 4 weeks. Tumor assessments are based on RECIST 1.1 and immune-related response criteria (irRC) and performed at baseline, and every 8 weeks after start of therapy, with an additional scan at 12 weeks for confirmation of response. Planned sample size is ≤ 25 pts in each arm. The primary efficacy endpoint for cohorts 1 and 2 is response rate (RR) at 4 months (per RECIST 1.1). The primary efficacy endpoint for cohort 3 is event free survival (EFS) rate at 4 months. If there is a high probability that the RR4 months is unlikely to be at least 20% for cohorts 1 and 2 or the EFS4 months is unlikely to be at least 40% for cohort 3 then the accrual of the corresponding cohort will be halted. The cohorts will be monitored separately for both futility and toxicity in groups of 5 after a minimum of 10 patients have been enrolled in each cohort. Secondary endpoints for the study include safety, best RR by RECIST and irRC, median PFS, and OS. Core needle biopsies and blood samples are collected at baseline and early on-treatment (week 6). Fresh flow cytometry is being performed to assess changes in T-cell activation, proliferation, and function and CD73 expression in the membrane and cytoplasm is being assessed by immunohistochemistry. Localization of tumor-infiltrating lymphocytes and engagement of the PD-1/PDL1 axis is being assessed using multiplex immunofluorescence staining. As of Jan 30th, 2022, twenty-two patients have initiated study treatment, 3 in cohort 1, 12 in cohort 2, and 7 in cohort 3. Clinical trial information: NCT04668300.