Naing, Aung

Abstract Purpose: Intratumoral injection of Clostridium novyi-nontoxic (C. novyi-NT), lacking alpha-toxin, germinates and subsequently replicates in the tumor hypoxic regions, causing cell lysis and inflammation. This phase Ib study investigated the safety and synergistic effects of pembrolizumab and C. novyi-NT in advanced solid tumors. Patients and Methods: Patients with injectable solid tumors received one intratumoral C. novyi-NT injection (day 8) across four dose cohorts (3 × 104 to 100 × 104 spores) with pembrolizumab (200 mg intravenously every 3 weeks, day 0–24 months). Sixteen patients were enrolled with a median age of 62.5 years, and the most common tumor types were breast cancer and melanoma. Results: The combination therapy demonstrated a manageable safety profile, with one grade 3 dose-limiting toxicity of abscess formation and the remainder of treatment-related adverse events in ≥10% of patients being grade 1 or 2 injection site reaction (25%), pyrexia (19%), pruritus (13%), leukopenia (13%), and anemia (13%). The maximum tolerated dose was determined to be pembrolizumab intravenously at 200 mg every 3 weeks and a single dose of 100 × 104C.novyi-NT spores intratumorally on day 8. The confirmed overall objective response rate of 25% was observed among four patients with nonkeratinizing undifferentiated nasopharyngeal squamous carcinoma, human papilloma virus–positive squamous cell carcinoma of the base of the tongue, vulvar melanoma, and chordoma. Among these patients, we obtained three partial responses and one complete response. The median duration of the response was 10.93 months, and stable disease was observed in 69% of patients. Conclusions: This study highlights the potential of the C. novyi-NT and pembrolizumab combination as a promising therapeutic strategy for treatment-refractory solid tumors.

Introduction This was the first phase 1 study conducted in the United States. It consisted of dose-escalation (part A) and multiple indication-specific cohort expansion (part B), investigating the safety and preliminary efficacy of toripalimab (anti–programmed cell death-1 inhibitor) in patients with advanced malignancies. Methods Patients with advanced malignancies that progressed after treatment with at least one prior line of standard systemic therapy, including the patients with advanced/recurrent cholangiocarcinoma (CCA), received toripalimab 240 mg every 3 weeks in part B. The primary endpoint was safety assessment. Efficacy endpoints included objective response rate (ORR), disease control rate (DCR), duration of response (DoR), progression-free survival (PFS) as assessed by the investigators according to Response Evaluation Criteria in Solid Tumors (version 1.1) and overall survival (OS). Results In part B, 166 patients, including the 42 patients with CCA, were enrolled and received toripalimab. Among the 166 patients, treatment-emergent adverse events (TEAEs) of any grade occurred in 158 (95.2%) patients, and 97 (58.4%) patients experienced TEAEs of Grade 3 or greater. The most common TEAE was fatigue (42.2%). Seven (4.2%) patients experienced TEAEs with a fatal outcome, none of which were identified by investigators as related to toripalimab. Investigator-assessed immune-related adverse events (irAE) of Grade 3 or higher occurred in 7 (4.2%) patients. In the CCA cohort, with the median follow-up of 4.4 months, the ORR and DCR were 4.8% (95% CI: 0.58, 16.16) and 40.5% (95% CI: 25.63, 56.72), respectively; median DoR was 7.8 (range 4.4+ to 7.8) months; median PFS was 2.1 (95% CI: 1.91, 3.88) months; median OS was not estimable. Conclusions Toripalimab had manageable side effects in patients with refractory cholangiocarcinoma and exhibited preliminary evidence of anti-tumor activity. However, further information regarding biomarkers is needed. ClinicalTrials.gov ID: NCT03474640

Abstract Background: NL-201 is a selective and long-acting computationally designed alpha-independent agonist of the IL-2 and IL-15 receptors, which share beta and gamma signaling subunits. NL-201 is being developed as a potent activator of CD8+ T cells and NK cells for cancer immunotherapy. Binding to the beta and gamma subunits stimulates dose-dependent expansion and tumor infiltration of cytotoxic CD8+ T cells and NK cells, thereby enhancing the immune response in the tumor. The absence of binding to the IL-2 alpha subunit reduces the undesirable effects of traditional IL-2 therapies, such as vascular leak syndrome and expansion of immunosuppressive regulatory T cells. As such, NL-201 is designed to promote the desired immunomodulatory anti-tumor effects of IL-2 with an improved safety profile. Methods: NL201-101 is a Phase 1 first-in-human, open-label, dose-escalation and cohort expansion study consisting of two parts. Part 1 is a monotherapy dose-escalation study in up to 60 adult patients with advanced and/or refractory solid tumors to define the safety profile and the recommended Phase 2 dose (RP2D) and schedule of NL-201. During dose escalation, two different schedules will be evaluated: dosing every 21 days (Schedule A), or on days 1 and 8 of each 21-day cycle (Schedule B). Tumor response will be assessed by Response Evaluation Criteria in Solid Tumours (RECIST) 1.1 and/or RECIST for use in cancer immunotherapy trials (iRECIST). In Part 2, patients with pathologically proven diagnosis of melanoma and renal cell carcinoma (up to N=30/cohort), who have advanced and/or refractory measurable disease and have failed at least one line of treatment, which may include checkpoint inhibitors, will be enrolled. Key exclusion criteria include history of brain cancer or active brain metastases, carcinomatous meningitis, neurologic autoimmune disease; patients previously receiving CAR-T or IL-2-based therapies are not eligible. Recruitment of Part 1 began in April 2021, and the trial is actively enrolling. Clinicaltrials.gov identifier: NCT04659629. Citation Format: Aung Naing, Margaret Callahan, Brian A. Costello, Brendan Curti, Evan Hall, Aaron Hansen, Georgina V. Long, Anthony M. Joshua, Cynthia Wetmore, Andrew Weickhardt. A first-in-human phase 1 study of NL-201 in patients with relapsed or refractory cancer [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 CT250.

TPS2670 Background: Tumor necrosis factor receptor-2 (TNFR2) is expressed on effector CD8+ T cells, CD4+ T cells, T regulatory cells, natural killer cells, and myeloid cells. Targeting TNFR2 is anticipated to yield effective anti-tumor immunity by stimulating T-cell and NK-cell activation and proliferation in the tumor microenvironment. HFB200301 is a first-in-class anti-TNFR2 agonistic monoclonal antibody that triggers both innate and adaptive immune stimulation by binding to a specific epitope on TNFR2. HFB200301 has demonstrated dose-dependent anti-tumor activity in human TNFR2 knock-in mice bearing MC38 and Hepa1-6 syngeneic tumors. Methods: HFB200301 is being evaluated in a first-in-human, open-label, multi-center, dose escalation and expansion study in adult patients with advanced solid tumors. A single-cell immune profiling platform, DIS, was deployed to identify unique tumor-infiltrating T cell signatures that could help optimize patient selection for HFB200301 treatment. It is hypothesized that the presence of an effector T cell subpopulation that express both TNFR2 and CD8A in solid tumors may represent a tumor microenvironment favorable to TNFR2 agonism. The following cancer indications have been identified based on the prevalence of a TNFR2 high/CD8 high signature: Epstein-Barr Virus positive (EBV+) gastric cancer, clear cell renal cell carcinoma (ccRCC), cutaneous melanoma, testicular germ cell tumor (TGCT), soft tissue sarcoma (STS), and PD-L1+ cancers: cervical cancer, pleural mesothelioma, lung adenocarcinoma, and head and neck squamous cell carcinoma (HNSCC). The escalation portion of the study explores increasing doses in cohorts of up to six patients, utilizing mTPI-2 design to determine recommended dose(s) for expansion (RDE(s)). Based on pharmacokinetic modeling to maximize HFB200301 activity, 60-minute intravenous infusions of HFB200301 are administered every 4 weeks. Once RDE(s) is determined, expansion into three indication-specific cohorts is planned to determine the recommended phase 2 dose (RP2D). Key eligibility criteria include histologically documented advanced or metastatic solid tumors in the above listed indications. Patient enrollment opened in February 2022 in the USA, with plans for additional clinical sites in Spain and China. The primary objective is to identify the RDE, characterize safety and tolerability of HFB200301, and determine RP2D. Secondary objectives include pharmacokinetic parameters, preliminary evidence of anti-tumor efficacy (e.g., ORR, DCR, DOR) and pharmacodynamic evaluation (e.g., T cell subsets) in the blood and in the tumor. Furthermore, a potential predictive biomarker signature derived based on the DIS single-cell immune profiling approach will be investigated retrospectively. Clinical trial information: NCT05238883.

Background This phase I multicenter study was designed to evaluate the safety, tolerability, efficacy, and translational effects on the tumor microenvironment of itacitinib (Janus-associated kinase 1 (JAK1) inhibitor) in combination with epacadostat (indoleamine 2,3-dioxygenase 1 (IDO1) inhibitor) or parsaclisib (phosphatidylinositol 3-kinase δ (PI3Kδ) inhibitor). Methods Patients with advanced or metastatic solid tumors were enrolled and received itacitinib (100–400 mg once a day) plus epacadostat (50–300 mg two times per day; group A), or itacitinib (100–400 mg once a day) plus parsaclisib or parsaclisib monotherapy (0.3–10 mg once a day; group B). Results A total of 142 patients were enrolled in the study. The maximum tolerated dose was not reached for either the combination of itacitinib plus epacadostat (n=47) or itacitinib plus parsaclisib (n=90). One dose-limiting toxicity of serious, grade 3 aseptic meningitis was reported in a patient receiving itacitinib 300 mg once a day plus parsaclisib 10 mg once a day, which resolved when the study drugs were withdrawn. The most common treatment-related adverse events among patients treated with itacitinib plus epacadostat included fatigue, nausea, pyrexia, and vomiting, and for patients treated with itacitinib plus parsaclisib were fatigue, pyrexia, and diarrhea. In the itacitinib plus epacadostat group, no patient had an objective response. Among patients receiving itacitinib 100 mg once a day plus parsaclisib 0.3 mg once a day, three achieved partial response for an objective response rate (95% CI) of 7.1% (1.50 to 19.48). Treatment with itacitinib plus epacadostat demonstrated some increase in tumor CD8+ T cell infiltration and minor changes in six plasma proteins, whereas treatment with itacitinib plus high-dose parsaclisib resulted in downregulation of 20 plasma proteins mostly involved in immune cell function, with no observed change in intratumoral CD8+ T cell infiltration. Conclusion Adverse events with JAK1 inhibition combined with either IDO1 or PI3Kδ inhibition were manageable, but the combinations demonstrated limited clinical activity or enhancement of immune activation in the tumor microenvironment. Trial registration number NCT02559492.

Abstract Purpose: The safety and preliminary efficacy of MEDI1873, an agonistic IgG1 fusion protein targeting glucocorticoid-induced TNF receptor–related protein (GITR), were evaluated in an open-label, first-in-human, phase I, dose escalation study in previously treated patients with advanced solid tumors. Patients and Methods: Two single-patient cohorts at 1.5 and 3 mg i.v. were followed by 3+3 dose escalation in six cohorts at 7.5, 25, 75, 250, 500, and 750 mg, all every 2 weeks, for up to 52 weeks. Primary endpoints were safety and tolerability, dose-limiting toxicities (DLT), and MTD. Secondary endpoints included antitumor activity, pharmacokinetics, immunogenicity, and pharmacodynamics. Results: Forty patients received MEDI1873. Three experienced DLTs: grade 3 worsening tumor pain (250 mg); grade 3 nausea, vomiting, and headache (500 mg); and grade 3 non-ST segment elevation myocardial infarction (750 mg). An MTD was not reached and treatment was well tolerated up to 500 mg. Most common treatment-related adverse events were headache (25%), infusion-related reaction (17.5%), and decreased appetite (17.5%). MEDI1873 exposure was dose proportional. Antidrug–antibody incidence was low. MEDI1873 increased peripheral CD4+ effector memory T-cell proliferation as well as cytokines associated with effector T-cell activation at dose levels ≥75 mg. The best response was stable disease (SD) in 17 patients (42.5%), including 1 unconfirmed partial response. Eight patients (20.0%) had SD ≥24 weeks. Conclusions: MEDI1873 showed acceptable safety up to 500 mg i.v. every 2 weeks with pharmacodynamics activity, and prolonged SD in some patients. However, further development is not planned because of lack of demonstrated tumor response.

Abstract Background: PD-L1 blockade with durvalumab (D) is approved as second-line therapy in platinum-refractory metastatic urothelial cancer (mUC). Adding CTLA-4 blockade with tremelimumab (T) may improve responses, particularly in pts with low PD-L1 expression. Here we report safety and efficacy in the mUC cohort of the dose-expansion phase of a phase I, multicenter, open-label study of D+T in pts with advanced solid tumors (NCT02261220). Methods: Pts with platinum-refractory mUC received D 20 mg/kg + T 1 mg/kg Q4W for 4 months, followed by D 10 mg/kg Q2W for a total of 12 months of treatment. The primary objectives were safety in the mUC cohort and antitumor activity in the subgroup with tumor cell and immune cell PD-L1 expression <25% (assessed by SP263 IHC assay). Secondary objectives included antitumor activity per RECIST v1.1 in other subgroups. Results: As of Oct 20 2017, 168 pts received treatment and had ≥24 weeks' follow-up. Median age was 65.5 yr (range, 35-85), 78.0% were male, 81.0% had visceral metastases (32.1% liver metastases) and 32.1% had received >1 prior line of chemotherapy. Median duration of follow-up was 11.6 mo. Treatment-related AEs occurred in 75.6% of pts and were Grade 3-4 in 28.6%. One pt died due to a treatment-related AE (pulmonary hemorrhage). Treatment-related AEs led to discontinuation of therapy in 11.9% of pts. Confirmed objective response rate (ORR) was 35/168 (20.8%) including 4 CRs. Responses occurred early (median 1.8 mo) and are durable (median DOR not reached, range 1.9-24.9 mo). At 6 months, the PFS rate was 25.4% and the OS rate was 60.9%. Median PFS was 1.9 mo and median OS was 9.5 mo. Clinical activity was seen regardless of PD-L1 status, but patients with either tumor or immune cell expression ≥25% had numerically higher response rates (29.4% vs 15.1%) and 6-month OS rates than those with <25% expression (Table). Conclusions: D+T had a manageable safety profile and encouraging antitumor activity and survival rate in previously treated mUC regardless of PD-L1 status. Response and survivalPD-L1 ≥25% (n=68)PD-L1 <25% (n=86)PD-L1 unknown (n=14)Total (N=168)Confirmed ORR (CR+PR)(95% CI), %29.4 (19.0-41.7)15.1 (8.3-24.5)14.3 (1.8-42.8)20.8 (15.0-27.8)Ongoing ORR, %60.092.310074.3Disease control rate (CR+PR+SD≥24 weeks) (95% CI), %32.4 (21.5-44.8)24.4 (15.8-34.9)42.9 (17.7-71.1)29.2 (22.4-36.7)Median PFS, months (95% CI)3.5 (1.9-3.7)1.8 (1.8-1.9)4.9 (1.8-NE)1.9 (1.8-3.4)PFS 6-month rate, %26.122.638.525.4Median OS, months (95% CI)*18.9 (8.1-NE)8.0 (4.8-10.0)16.4 (7.3-16.4)9.5 (8.1-18.9)OS 6-month rate, %66.451.991.760.9NE, not estimable *Should be interpreted with caution due to limited follow-up at data cutoff Citation Format: Arjun V. Balar, Amit Mahipal, Enrique Grande, Victor M. Villalobos, Sebastien Salas, Taek Won Kang, Se Hyun Kim, Thomas Powles, Frank Tsai, Aung Naing, Albiruni Razak, Yohann Loriot, Ji Youl Lee, Sang Joon Shin, Rafael Morales-Barrera, Natasha Angra, Feng Xiao, Shaad Abdullah, Michiel S. Van der Heijden. Durvalumab + tremelimumab in patients with metastatic urothelial cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr CT112.

Abstract Sphingosine kinase 1 (SphK1) phosphorylates pro-apoptotic sphingosine to form pro-survival sphingosine-1-phosphate (S1P), leading to cancer progression. In breast cancer, high levels of SphK1 mRNA are found in 80% of the patients, with average increase of 2-fold in breast tumors compared with normal tissue from the same patient. Recent studies suggest that SphK1 expression is associated with disease-free survival in ER-negative and HER2-positive breast tumors. In addition, inhibition of SphK1 in HER2-positive breast cancer cell line reduced S1P-induced HER2 and ERK1/2 activation. While these evidences suggest that SphK1 may play an important role in HER2-positive breast cancer, the exact role of SphK1 in breast tumorigenesis remains unclear. The aim of this project is to define the role of SphK1 in HER2-positive breast tumorigenesis and to investigate whether the pathway components are potential target for breast cancer prevention and therapies. Here, we report that SphK1 is required for HER2/neu-induced breast tumorigenesis and SphK1 regulates claudin-2 (CLDN2) to promote tumor development perhaps by mediating HER2. In MMTV-neu transgenic mouse model, genetic deletion of SphK1, which was accompanied by reduced S1P and increased C16-ceramide levels, significantly inhibited breast tumor development, with reduced incidence (SphK1-/-, 19%; SphK1+/-, 26%; and SphK1+/+, 57%; p < 0.05) and multiplicity (SphK1-/-, 0.27 ± 0.13; SphK1+/-, 0.32 ± 0.07; and SphK1+/+, 0.67 ± 0.14 tumors per animal; p < 0.05). Unexpectedly, SphK1 deletion did not affect tumor growth as results showed no differences in tumor volume. However, this is not surprising when considering the fact that the tumors were allowed to grow until tumor reached 20 mm in longer diameter, at which they were sacrificed regardless of age. Interestingly, whole genome expression analysis by Illumina MouseWG-6 v2.0 Expression BeadChip Array revealed significant reduction of CLDN2 expression in tumors from SphK1 deficient mice (p < 0.0001). In support to these findings, overexpression of SphK1 in MDA-MB-453 human breast cancer cells, which HER2 is amplified but lacks hormone receptors, lead to increase in CLDN2 expression (p < 0.05). Furthermore, overexpression of SphK1 in MDA-MB-453 cells also enhanced cell proliferation, colony formation, and migration/invasion, and drug resistance to cisplatin. The relevance of this finings in humans was confirmed by immunostaining of SphK1 and CLDN2 in HER2-positive breast cancer tumors and normal tissues (n = 93 and 35 subjects, respectively). The results showed that the expression of SphK1 was higher in tumors compared to adjacent normal tissue (p < 0.0001). Furthermore, higher SphK1 expression was observed in high grade tumors (vs low grade; p < 0.001) and ER-PR- tumors (vs ER+PR+; p < 0.0001). Interestingly, we observed similar staining pattern of CLDN2 proteins, where CLDN2 expression was high in tumors (p < 0.0001), particularly in high grade tumors (p < 0.01) and ER-PR- tumors (p < 0.0001). Moreover, we found a strong correlation between SphK1 and CLDN2 expressions in tumors but not in normal tissues, confirming the results obtained in animal study. Taken together, these findings suggest that SphK1 may play a pivotal role in HER2-positive breast carcinogenesis, and targeting SphK1 and/or CLDN2 may represent a novel approach for HER2-positive breast cancer chemoprevention and/or treatment. Citation Format: Yoshiko Shimizu, Hideki Furuya, Paulette M. Tamashiro, Steve Goodison, Owen Chan, Ian Pagano, Kayoko Iino, Rafael Peres, Kanani Hokutan, Lenora W.M. Loo, Brenda Hernandez, Aung Naing, Charles J. Rosser, Toshihiko Kawamori. Genetic deletion of sphingosine kinase 1 suppresses mouse breast tumor development in MMTV-neu transgenic model. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research; Oct 17-20, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(2_Suppl):Abstract nr B17.