Merkel cell carcinoma is among the most aggressive and lethal of primary skin cancers, with a high rate of distant metastasis. Anti-programmed death receptor 1 (anti-PD-1) and programmed death ligand ...1 (PD-L1) monotherapy is currently standard of care for unresectable, recurrent, or metastatic Merkel cell carcinoma. We assessed treatment with combined nivolumab plus ipilimumab, with or without stereotactic body radiotherapy (SBRT) in patients with advanced Merkel cell carcinoma as a first-line therapy or following previous treatment with anti-PD-1 and PD-L1 monotherapy.
In this randomised, open label, phase 2 trial, we randomly assigned adults from two cancer sites in the USA (one in Florida and one in Ohio) to group A (combined nivolumab and ipilimumab) or group B (combined nivolumab and ipilimumab plus SBRT) in a 1:1 ratio. Eligible patients were aged at least 18 years with histologically proven advanced stage (unresectable, recurrent, or stage IV) Merkel cell carcinoma, a minimum of two tumour lesions measureable by CT, MRI or clinical exam, and tumour tissue available for exploratory biomarker analysis. Patients were stratified by previous immune-checkpoint inhibitor (ICI) status to receive nivolumab 240 mg intravenously every 2 weeks plus ipilimumab 1 mg/kg intravenously every 6 weeks (group A) or the same schedule of combined nivolumab and ipilimumab with the addition of SBRT to at least one tumour site (24 Gy in three fractions at week 2; group B). Patients had to have at least two measurable sites of disease so one non-irradiated site could be followed for response. The primary endpoint was objective response rate (ORR) in all randomly assigned patients who received at least one dose of combined nivolumab and ipilimumab. ORR was defined as the proportion of patients with a complete response or partial response per immune-related Response Evaluation Criteria in Solid Tumours. Response was assessed every 12 weeks. Safety was assessed in all patients. This trial is registered with ClinicalTrials.gov, NCT03071406.
50 patients (25 in both group A and group B) were enrolled between March 14, 2017, and Dec 21, 2021, including 24 ICI-naive patients (13 52% of 25 group A patients and 11 44% of 25 group B patients) and 26 patients with previous ICI (12 48% of 25 group A patients and 14 56% of 25 group B patients). One patient in group B did not receive SBRT due to concerns about excess toxicity. Median follow-up was 14·6 months (IQR 9·1–26·5). Two patients in group B were excluded from the analysis of the primary endpoint because the target lesions were irradiated and so the patients were deemed non-evaluable. Of the ICI-naive patients, 22 (100%) of 22 (95% CI 82–100) had an objective response, including nine (41% 95% CI 21–63) with complete response. Of the patients who had previously had ICI exposure, eight (31%) of 26 patients (95% CI 15–52) had an objective response and four (15% 5–36) had a complete response. No significant differences in ORR were observed between groups A (18 72% of 25 patients) and B (12 52% of 23 patients; p=0·26). Grade 3 or 4 treatment-related adverse events were observed in 10 (40%) of 25 patients in group A and 8 (32%) of 25 patients in group B.
First-line combined nivolumab and ipilimumab in patients with advanced Merkel cell carcinoma showed a high ORR with durable responses and an expected safety profile. Combined nivolumab and ipilimumab also showed clinical benefit in patients with previous anti-PD-1 and PD-L1 treatment. Addition of SBRT did not improve efficacy of combined nivolumab and ipilimumab. The combination of nivolumab and ipilimumab represents a new first-line and salvage therapeutic option for advanced Merkel cell carcinoma.
Bristol Myers Squibb Rare Population Malignancy Program.
Abstract
Background: In the past few years, anti-PD-1 and anti-CTLA4 immune-based therapeutics have revolutionized melanoma therapy, but many patients do not respond. The IFX-Hu2.0 formulation ...consists of a vector encoding a streptococcal membrane protein Emm55 and a cationic polymer. When IFX-Hu2.0 is injected into murine or equine melanomas, tumors regress. Transfection of the emm55 vector into B16 melanoma cells resulted in expression of Emm55 as measured by RT-PCR. Systemic immune responses elicited by IFx-Hu2.0 in B16 bearing mice were CD4 and CD8 T cell dependent and antigen specific. Antigen specificity was tested utilizing a M05 tumor model (B16 cells transfected with the Ovalbumin gene). Mice received 5*106 OT-1 T cells (T cells that have transgenic TCR that recognizes OVA). Tumors were harvested (48 hours) and tetramer specific CD8+ T cells were increased in treated mice. Given this preliminary data, we proceeded to design a first in human Phase I feasibility trial (single dose level with no dose escalation) to test IFx-Hu2.0 use as an intralesional immunotherapy for melanoma to provoke the immune response by facilitating Emm55 antigen surface expression and enhancing tumor recognition.
Methods: The primary objective is to assess the safety, tolerability, and feasibility of intralesional injection with IFx-Hu2.0 as a monotherapy in 6 adult patients (>18 years) with unresectable stage III or stage IV cutaneous melanoma lesions. To be eligible, a patient must have at least 1 injectable lesion and 1 un-injected lesion available for biopsies, but up to 3 lesions may be injected. Unlike other trials for melanoma, only 3 mm cutaneous lesions are needed. Patients must have failed, refused or been deemed not candidates for one form of systemic anti-PD-1-based immunotherapy as well as BRAF inhibition, if BRAF V600 mutated. In addition, patients with unresectable cutaneous, subcutaneous, and nodal melanoma lesions recurrent after initial surgery must have failed, refused or not candidates for TVEC. Patients may be enrolled with brain metastases (<1 cm) as long as they are receiving radiation with a life expectancy of >3 months, but may not be receiving concurrent chemotherapy/biological therapy, have uncontrolled hepatitis B/C/HIV infection, or have a history of organ allograft transplantation. Concurrent radiotherapy is allowed at distant sites from the injected lesion. 40 mL of peripheral blood will be collected prior to treatment and at the follow-up visit (28 days) for correlative studies to complement the preclinical murine models. Patients responding to therapy may continue dosing every 3 weeks thereafter. Feasibility is defined as the ability to treat five of the six patients enrolled without dose-limiting toxicity (28 days). As of January 2019, 1/6 of the planned patients have been enrolled. Clinical trial registry number: NCT03655756.
Citation Format: Joseph Markowitz, Krithika N. Kodumudi, Deanryan B. De Aquino, Vernon K. Sondak, Shari Pilon-Thomas. Trial in progress: First in human Phase I study using a plasmid DNA coding for Emm55 streptococcal antigen (IFx-Hu2.0) in patients with unresectable stage III or stage IV cutaneous melanoma abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT119.
High-throughput sequencing (HTS) has revolutionized researchers' ability to study the human transcriptome, particularly as it relates to cancer. Recently, HTS technology has advanced to the point ...where now one is able to sequence individual cells (i.e., "single-cell sequencing"). Prior to single-cell sequencing technology, HTS would be completed on RNA extracted from a tissue sample consisting of multiple cell types (i.e., "bulk sequencing"). In this chapter, we review the various bioinformatics and statistical methods used in the processing, quality control, and analysis of bulk and single-cell RNA sequencing methods. Additionally, we discuss how these methods are also being used to study tumor heterogeneity.
DNA methylation signatures in tumors could serve as reliable biomarkers that are accessible in archival tissues for tracking the epigenetic dynamics shaped by both cancer cells and the tumor ...microenvironment. However, given the ultrahigh dimensionality and noncollapsible nature of the data, it remains challenging to screen all CpG sites to identify the most promising marker panels. In this article, we introduce the concept of tumor-based expression quantitative trait methylation (eQTM) for the prioritization and systematic mining of predictive biomarkers. In melanoma as a disease model, eQTM CpGs and genes represent new and efficient candidate targets to be investigated for both prognostic and immune status monitoring purposes. Three cis-eQTM CpGs (cg07786657, cg12446199, and cg00027570) were strongly associated with and can serve as surrogate biomarkers for the tumor immune cytolytic activity score (CYT). In addition, multiple eQTM genes could be further exploited for predicting immunoregulatory phenotypes. A targeted gene panel analysis identified one eQTM in TCF7 (cg25947408) as a novel candidate biomarker for uncoupling overall T-cell differentiation and exhaustion status in a tumor. The prognostic significance of this eQTM as an independent signature to CYT was validated by both The Cancer Genome Atlas and Moffitt melanoma cohort data. Overall, eQTMs represent a mechanistically distinct class of potential biomarkers that can be used to predict patient prognosis and immune status.
This study provides a novel and promising approach to identify targeted epigenetic biomarkers in cancer and will spur further analysis in tumor immune phenotyping.
9534
Background: Merkel cell carcinoma (MCC) and cutaneous squamous cell carcinoma (cSCC) exhibit high response rate to immune checkpoint inhibitor (ICI) therapy. However, patients with advanced ...disease who fail initial ICI therapy have limited treatment options. IFx-Hu2.0 (IFx) is a plasmid DNA encoding for an immunogenic bacterial protein, Emm55, formulated with a transfection agent for direct intratumoral injection. In a phase 1 study in advanced melanoma, biomarker analyses demonstrated robust immune priming effects of IFx administration. As part of an ongoing Phase 1b study, we evaluated the safety and immunologic response of different schedules of IFx intratumoral administration in patients with advanced MCC or cSCC. We report the initial results of the first stage of this study. Methods: In the first trial stage (n = 9), IFx was administered intratumorally in up to 3 lesions on 3 schedules; weekly x 1, 2, or 3. We report safety data for these patients. Given the proposed potential for immune priming effects of IFx, we performed an unplanned exploratory analysis of post-protocol treatment efficacy to evaluate for response to ICI rechallenge if given. Results: Five patients with advanced MCC and four with cSCC were enrolled. Prior to trial enrollment, all patients with MCC received ICI with pembrolizumab (4) or avelumab (1), all had progressive disease with median 3 months treatment (2.0-4.5mo). All 4 patients with cSCC previously received cemiplimab with median 6 months treatment (3.0-11.5mo). IFx was well tolerated at all dose schedules evaluated with no treatment-related G3-5 adverse events observed. Best response to trial therapy was SD in 2 patients and PD in seven. One MCC patient experienced complete clinical response in 2 injected lesions, but progression of disease overall with development of new disease areas. Following completion of protocol therapy, all 5 MCC patients and 2 of 4 cSCC patients were treated with anti-PD(L)1 therapy as the immediate post-protocol therapy: pembrolizumab (3) or avelumab (2) in MCC and cemiplimab (2) in cSCC. Four of 5 MCC patients and 1 of 2 cSCC patients, or 5 of 7 total (71%), experienced objective response to ICI rechallenge in this setting, with duration of response ongoing in 4 patients (7+, 8+, 9+, 20+ months) and one response lasting 23 months. Conclusions: IFx-Hu2.0 is safe and well tolerated at weekly dosing repeated up to 3 weeks. An exploratory analysis showed that five of seven patients (71%) treated with standard of care ICI agents following protocol therapy experienced a durable objective response despite prior failure of this same drug class prior to protocol enrollment. An additional 11 patients are planned for enrollment in the expansion stage of the study using the weekly x3 dosing schedule. Preliminary biomarker analyses from the first nine patients are ongoing and will be presented. Clinical trial information: NCT04160065 .
We have reported previously that CD33hi myeloid-derived suppressor cells (MDSCs) play a direct role in the pathogenesis of myelodysplastic syndromes (MDSs) and that their sustained activation ...contributes to hematopoietic and immune impairment, including modulation of PD1/PDL1. MDSCs can also limit the clinical activity of immune checkpoint inhibition in solid malignancies. We hypothesized that depletion of MDSCs may ameliorate resistance to checkpoint inhibitors and, hence, targeted them with AMV564 combined with anti-PD1 in MDS bone marrow (BM) mononuclear cells (MNCs) enhanced activation of cytotoxic T cells. AMV564 was active in vivo in a leukemia xenograft model when co-administered with healthy donor peripheral blood MNCs (PBMCs). Our findings provide a strong rationale for clinical investigation of AMV564 as a single agent or in combination with an anti-PD1 antibody and in particular for treatment of cancers resistant to checkpoint inhibitors.
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CD33hi MDSCs play a direct role in the pathogenesis of malignancy, contributing to hematopoietic and immune impairment (PD1/PDL1), limiting the clinical activity of immune checkpoint inhibition. We show that targeting CD33hi MDSCs with AMV564, a CD33/CD3 bivalent, bispecific antibody, with or without anti-PD1 in primary specimens restores anti-tumor immunity.
Myeloid derived suppressor cells (MDSC) produce nitric oxide (NO) and inhibit dendritic cell (DC) immune responses in cancer. DCs present cancer cell antigens to CD4
T cells through Jak-STAT signal ...transduction. In this study, NO donors (SNAP and DETA-NONOate) inhibited DC antigen presentation. As expected, MDSC isolated from peripheral blood mononuclear cells (PBMC) from cancer patients produced high NO levels. We hypothesized that NO producing MDSC in tumor-bearing hosts would inhibit DC antigen presentation. Antigen presentation from DCs to CD4
T cells (T cell receptor transgenic OT-II) was measured via a
H-thymidine incorporation proliferation assay. MDSC from melanoma tumor models decreased the levels of proliferation more than pancreatic cancer derived MDSC. T cell proliferation was restored when MDSC were treated with inhibitors of inducible nitric oxide synthase (L-NAME and NCX-4016). A NO donor inhibited OT II T cell receptor recognition of OT II specific tetramers, thus serving as a direct measure of NO inhibition of antigen presentation. Our group has previously demonstrated that STAT1 nitration also mediates MDSC inhibitory effects on immune cells. Therefore, a novel liquid chromatography-tandem mass spectrometry assay demonstrated that nitration of the STAT1-Tyr701 occurs in PBMC derived from both pancreatic cancer and melanoma patients.
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9562
Background: Anti-PD1 (aPD1) monotherapy with cemiplimab-rwlc or pembrolizumab is now considered standard of care for first-line management of advanced CSCC not amenable to surgery ...or curative radiotherapy. Previously chemotherapy or anti-EGFR agents were commonly used for these patients albeit with modest efficacy and limited duration of response. In prospective evaluation, the overall response rate (ORR) to cetuximab was 28% with disease control rate (DCR) of 69% at 6 weeks. The efficacy of second-line treatment following primary or acquired resistance to aPD1 therapy is not known. We investigated the activity of cetuximab in patients who progressed on previous IO therapy. Methods: We performed a single institution retrospective review from 9/28/18 (US approval date of cemiplimab-rwlc for CSCC) through 11/30/20 of patients with locally advanced or metastatic CSCC who received cetuximab after prior IO therapy. We identified patients who received cetuximab either immediately following IO therapy (cohort A) or as a subsequent line not immediately following IO therapy (cohort B). Primary endpoint was ORR with secondary endpoints of DCR, survival and toxicity. Median follow-up and survival times were calculated using the Kaplan-Meier method. Results: Thirteen patients, median age 72 years (62-82), all Caucasian, and 11 males (85%) were included in this study. Eleven pts received cetuximab immediately post-IO progression; two had additional intervening therapy post-IO before receiving cetuximab. Three patients received concurrent radiotherapy (palliative or definitive) with cetuximab. The ORR to cetuximab was 54% (7/13) including 1 complete and 6 partial responses. The cumulative 6-month DCR was 77%. All responses were observed in cohort A; both patients in cohort B had progressive disease as best response. Six of 7 initial responses are ongoing, including 3 in whom cetuximab was discontinued. At a median follow-up of 9.1 months, the median PFS has not been reached for the entire cohort. There were no unanticipated toxicities to cetuximab with rash (77%) and hypomagnesemia (54%) being the most common adverse events. Conclusions: In advanced CSCC, cetuximab used immediately after progression on aPD1 therapy yields notably higher and durable overall response than previously reported in the pre-IO therapy era. If validated in a larger dataset, this should be the preferred therapy for second-line treatment in advanced CSCC. Further exploration into the mechanism of this high efficacy of anti-EGFR therapy post aPD1 therapy is warranted.
TPS9612 Background: Prognosis in metastatic uveal melanoma (UM) has historically been poor approximating 1 year from diagnosis. Tebentafusp is the only approved systemic agent for HLA-A*02:01 ...positive metastatic UM, and novel therapies are needed. The melanocortin-1 receptor (MC1R) receptor is highly expressed in UM with limited expression in normal tissues. Actinium-225 ( 225 Ac) is an alpha particle emitting radionuclide ideal for targeted ligand binding due to high linear energy transfer and limited free path (<100 µm) in tissue. We developed a novel MC1R targeted radiopharmaceutical 225 Ac-MTI-201, and demonstrated high biostability, affinity, MC1R-specific cytotoxicity with defined dosimetry and pharmacokinetics in pre-clinical studies (1). Murine efficacy studies of UM showed significant delay of tumor growth and improved survival compared to controls. Methods: This is a single institution first-in-human phase I study (NCT05496686) of 225 Ac-MTI-201 in metastatic UM. The primary objective is to determine the safety of a single intravenous dose of 225 Ac-MTI-201 relative to radioactivity dose. Secondary endpoints include 1) pharmacokinetics (PK) and clearance of 225 Ac-MTI-201, 2) objective response rate and duration, progression-free survival, and overall survival in metastatic UM. Salient eligibility criteria include: 1) age ≥18 years; 2) histologically confirmed metastatic UM with progression after at least 1 prior line of therapy; 3) measurable disease per Response Evaluation Criteria in Solid Tumors version 1.1; 4) Eastern Cooperative Oncology Group performance status of ≤1; 5) adequate marrow, renal and hepatic function; 6) no more than 25% of bone marrow treated with prior radiotherapy. Patients will receive a single dose of 225 Ac-MTI-201 under appropriate guidelines and precautions for administration of radiopharmaceuticals. Pre-injection and post-injection PK sampling at defined intervals are undertaken. There are 12 dose levels for 225 Ac-MTI-201 being investigated ranging from 4.7 microcurie (µCi) to 1327 µCi. Dose escalation is done using a modified continual re-assessment method with a cohort size of one based on dose limiting toxicity (DLT) assessment within 28 days of drug administration using CTCAE v5.0. Definitions of DLT include G4 neutropenia or febrile neutropenia, G4 thrombocytopenia or G3 thrombocytopenia with clinically significant bleeding, > G3 non-hematological toxicity with selected exceptions, laboratory abnormalities that satisfy Hy’s law, or any death not related to underlying disease or extraneous cause. Response assessments are undertaken with cross-sectional imaging every 8 weeks in year 1, and every 12 weeks in year 2. This study is currently open for enrollment. Dose levels 1-4 have been completed without DLT. 1. Tafreshi, J Nucl Med 2019. Clinical trial information: NCT05496686 .
e21542
Background: Many melanoma patients do not respond to anti-PD1 therapy due to lack of antigen specific responses. IFx-Hu2.0 (plasmid DNA encoding the streptococcal membrane protein, Emm55, ...contained within a cationic polymer) primes innate and antigen dependent responses in murine/equine melanoma models to produce an environment needed for checkpoint inhibitor efficacy. We describe the first in human study utilizing IFx-Hu2.0 in unresectable melanoma - NCT03655756. Methods: Melanoma patients (unresectable stage III/IV) had cutaneous lesions injected with IFx-Hu2.0 to test safety and feasibility. Patients were refractory to standard of care (anti-PD1, BRAF/MEK) or did not wish these treatments. 1-3 lesions (> 3 mm – 0.1 mg/0.2 mL) were injected, pre/post treatment biopsies obtained, and the primary endpoint of 5/6 patients without dose limiting toxicity (DLT) was assessed at 28 days. Retreatment was permitted. ≥2 lesions were needed: one for injection and uninjected lesion for biopsy. Tissue samples were analyzed for mRNA profiles, antigen responses (PEPperPRINT assay), and multiplex immunofluorescence (markers: CD3, CD8, FOXP3, PD1, PDL1, SOX10, DAPI). Results: The primary endpoint was met in 6 evaluable patients out of 7 enrolled. Observed toxicities included: G1-2 Injection site reactions - 5/7; G1 Bleeding - 1/7; G1-2 Pain - 2/7, G1 Lymphopenia - 1/7, G1 Pruritis - 1/7; with no ≥ G3 toxicities related to study drug observed. One G5 toxicity (Clostridium septicum infection 20 days post injection) was deemed unlikely related to study drug. 5/6 patients received 1 cycle prior to post-protocol immune-based therapy. One treatment naïve patient retreated once with IFx-Hu2.0 required no additional therapy > 9 months. Available paired tissue and plasma sampling revealed increased T cell infiltration into treated lesions, increase in IgM and IgG epitope recognition to melanoma associated antigens in the plasma (detected by PEPperPRINT assay), an increase in mRNA associated with innate immune responses in the injected lesion (CXCL13, LAG3, CXCL11, CXCL10, ICOS) and an adaptive immune response (IL-12, HLA-DRB5, WNT4, CD3D, Arg I) in uninjected lesions associated with downregulation of known melanoma antigens. Of 4 anti-PD1 refractory patients, three patients had clinical benefit to post-protocol retreatment with anti-PD1 based therapy (Stable Disease (SD) lasting > 2 years followed by surgical resection, Partial Response (PR) lasting > 9 months, PR subsequently surgical resected and rendered no evidence of disease). Conclusions: In this pilot study, intralesional IFx-Hu2.0 demonstrated a favorable safety profile. These data support encouraging immunological correlative responses and further study of IFx-Hu2.0 as a priming agent to enhance or restore sensitivity to immune checkpoint inhibitor therapy in melanoma. Clinical trial information: NCT03655756.
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