Block, Matthew S.

Clinical stage III melanoma, defined as resectable RECIST measurable nodal disease with or without in-transit metastases, represents approximately 15% of new melanoma diagnoses every year with additional cases presenting as recurrent nodal disease following previous treatment of a primary melanoma. The standard of care for patients with resectable clinical stage III melanoma is surgical resection, consisting of therapeutic lymph node dissection and/or resection of in-transit disease and consideration of adjuvant systemic therapy and occasionally adjuvant radiation. These patients have high rates of regional recurrence and progression to metastatic disease postsurgery, highlighting the need for better treatment options. With the success of immune checkpoint inhibitors in both the adjuvant and metastatic settings, the use of these agents in the neoadjuvant setting has been an emerging area of research interest. In this chapter, we will discuss the rationale for neoadjuvant immunotherapy; review impactful clinical trials; and define response monitoring, surgical considerations, emerging therapies, and unanswered questions for neoadjuvant therapy as a recent paradigm shift in the management of clinical stage III melanoma.

Abstract Background: Head and Neck (HNSCC) and Ovarian cancer (OC) are two indications for which immunotherapy had limited impact so far. Current treatments achieve high rates of initial success through surgery and adjuvant chemo/radiotherapy, but patients (pts) remain at high risk of relapse in both indications. Immune stimulation using a vaccine is a promising strategy to a clinically meaningful improvement. Herein we report phase I data of TG4050, a vaccine engineered to carry a pt tailored antigen payload, in pts with HNSCC (NCT04183166) or OC (NCT03839524). Methods: Tumor specific variants are identified using next generation sequencing of tumor and normal samples whereby immune relevant mutations are predicted using a machine learning algorithm factoring in parameters known to affect immunogenicity including MHC binding, level of expression, prevalence across clones, and antigen processing. DNA sequences of the mutations of interest, typically 30 per pt, are cloned in a viral vector (Modified Vaccinia Virus Ankara). Following curative intent treatment, HNSCC pts in complete remission were randomized to an immediate vaccination arm to receive weekly doses of TG4050 for 6 weeks followed by a maintenance period of one dose every 3 weeks for up to 20 doses or to a delayed vaccination arm where the same vaccination regimen is initiated at relapse. OC pts received the vaccine upon onset of signs of relapse. PBMC were collected at Baseline and after 6 doses of vaccine. Primary endpoint was vaccine safety and secondary endpoints included feasibility, immunogenicity. Results: 18 pts received TG4050 (5 OC and 13 HNSCC) treatment with no related grade ≥ 3 adverse events. Tumor mutational burden (TMB) was on average 3.00±0.98 and 2.43±0.69 mutations per megabase for HNSCC and OC respectively. Despite this low TMB, all pts had sufficient cancer specific neoantigens to design a vaccine. Ex-vivo ELISPOT was completed for 7 pts at the time of submission. A mean of 44% of selected mutations were associated with a reactive T cell responses either spontaneously or after TG4050 stimulation ranging from 6 to 22 mutations per pt. Vaccination induced a stimulation of T cell response in all tested pts on an average of 10 targeted mutations, induction of de novo responses was seen in all 7 tested pts and amplification of pre-existing response in 6/7 pts. None of the evaluable HNSCC pts receiving TG4050 immediately after first line treatment had relapse after a median follow-up of 7 months while 2 pts had relapse in the delayed vaccination arm. Furthermore, in OC pts treated at early relapse, TG4050 has normalized disease markers (ctDNA and/or CA-125) for 2/4 pts with stable disease for 9 and 11 months. Conclusion: TG4050 treatment is feasible and immunogenic in pts with low to moderate TMB. It is effective in inducing T cell responses and first signs of antitumor activity are encouraging for the continuation of development. Citation Format: Ana Lalanne, Camille Jamet, Christian H. Ottensmeier, Jean-Pierre Delord, Christophe Le Tourneau, Matthew S. Block, Gerardo Colon-Otero, Keith L. Knutson, Annette Tavernaro, Gisele Lacoste, Benoit Grellier, Xavier Noiriel, Thierry Huss, Bernard Burtin, Yoshiko Yamashita, Kousuke Onoue, Kazuhide Onoguchi, Brandon Malone, Olivier Lantz, Oliver Baker, Naoko Yamagata, Yuki Tanaka, Eric Quemeneur, Maud Brandely, Kaidre Bendjama. Feasibility and immunogenicity of adjuvant TG4050, a patient tailored cancer vaccine in head and neck and ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr LB205.

Abstract Oncologic viruses (OV) can induce tumor death through both direct oncolysis and immune-mediated destruction. Our study investigates the use of a novel OV with a Vesicular Stomatitis Virus (VSV) vector modified to express interferon-beta (IFN-b) and Tyrosinase Related Protein 1 (TYRP1) (VSV-IFNb-TYRP1). VSV is an attractive vector since humans are not naturally infected with VSV; thus, pre-existing immunity is minimal. IFN-b leads to increased T-cell responses and tumor cell apoptosis, while TYRP1, a melanocyte differentiation antigen, increases immunogenicity of the therapy. We conducted a Phase 1 clinical trial with a 3+3 design in patients with metastatic uveal melanoma. VSV-IFNb-TYRP1 was injected into a liver metastasis under image guidance, then administered on the same day as a single intravenous (IV) infusion. IV doses started at dose level (DL) 1 1 × 1010 TCID50, then escalated to DL2 3 × 10 10, DL3 1 × 1011, and DL4 3 × 1011. The dose delivered intratumorally (IT) varied based on the IV dose. The primary endpoints were safety and maximum tolerated dose (MTD). Efficacy was a secondary endpoint. Correlative studies focused on understanding viral pharmacokinetics (PK) and immunological responses induced by VSV-IFNb-TYRP1 therapy. Twelve patients with previously treated metastatic uveal melanoma were enrolled. Median follow up was 19.1 months. Four DLs were evaluated with one patient at DL4 experiencing dose limiting toxicities (DLTs), including decreased platelet count (grade 3), increased aspartate aminotransferase (AST), and cytokine release syndrome (CRS). Non-DLTs at DL4 were fatigue, fever, CRS, hematological toxicities (decreased platelets and lymphocytes), and AST elevation. Four patients had stable disease (SD) and 8 had progressive disease (PD) as their best response. ELIspot data show that three of the four patients with response to TYRP1 also had a response to gp100, suggesting possible epitope spreading. These four patients received immune checkpoint inhibitor treatment as the next line of therapy, which led to clinical benefit for two patients. Our study evaluated VSV-IFNb-TYRP1 administered via IT and IV routes in a previously treated population of metastatic uveal melanoma patients and found no major safety events. Although there were no clear objective responses to VSV-IFNb-TYRP1, dose-dependent immunogenicity to melanoma antigens was seen. While OV response alone is not sufficient for clinical benefit, the evidence of epitope spreading is encouraging. Future studies of VSV-IFNb-TYRP1 will evaluate combinations with other therapies. Citation Format: Katherine E. Smith, Adam Weisbrod, Carrie Strand, Jacob Allerd, Jose S. Pulido, Alysha Newsom, Lianwen Zhang, Nandakumar Packiriswamy, Heather Montane, Lisa Kottschade, Anastasios Dimou, Yiyi Yan, Markovic Svetomir, Kah Whye Peng, Richard G. Vile, Matthew S. Block, Roxana S. Dronca. Phase I trial of vesicular stomatitis virus expressing human interferon beta and tyrosinase related protein 1 (VSV-IFNb-TYRP1) in metastatic ocular melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr CT207.

Abstract Purpose: Melanocortin 1 receptor (MC1R) has been shown in animal models to be a target for effective radionuclide therapy. This first-in-human clinical trial studied the safety and biodistribution of two novel MC1R-targeted imaging tracers designed to support the development of MC1R-targeted alpha particle therapy through image-based identification of MC1R and radiation dosimetry. Imaging was compared to MC1R expression by immunohistochemistry (IHC) of subjects’ melanoma tumors. Methods: Subjects with stage IV melanoma were randomized to receive either [203Pb]VMT01 SPECT/CT imaging followed by [68Ga]VMT02 PET/CT imaging approximately 1 month later, or vice versa in a cross-over design during their normal melanoma treatment course. Patient selection included a positive [18F]FDG PET/CT within 30 days of imaging tracer injection. 555 - 925 mBq of [203Pb]VMT01 was injected IV with imaging performed at 1, 4, and 24 hours. 74 - 277 mBq [68Ga]VMT02 was injected IV and imaging performed dynamically up to 1 hour, and at 2 and 3 hours. Due to an interruption in drug supply, only 3 subjects received [203Pb]VMT01 imaging. Key FDG-avid melanoma lesions were marked and presented to three experienced Radiologists serving as blinded reviewers. The blinded reviewers compared [18F]FDG PET/CT to experimental imaging and scored scans and key lesions on multiple metrics. Imaging positivity was defined as tumor uptake and retention of tracer in ≥ 1 melanoma tumors above background liver activity. Melanoma biopsy tissue was obtained and MC1R IHC performed as available. Results: 7 subjects were enrolled; 6 were imaged and 5 had available pathology. 3 of 6 imaged subjects had MC1R positive tumors via experimental imaging tracers. [68Ga]VMT02 PET/CT at 3 hours led to the best tumor to background ratio, and [203Pb]VMT01 SPECT/CT showed tumor retention at 24 hours. 4 of 5 subjects had positive MC1R staining by IHC. Of the 3 subjects with negative imaging, 2 had positive staining by IHC. Of the 3 subjects with positive imaging, 2 had available biopsies and all stained positive for MC1R by IHC. Conclusion: A subgroup of advanced melanoma patients were identified to express MC1R using new MC1R-targeted imaging agents. Full concordance between imaging and IHC of positive scans, but not with negative scans, suggests that IHC is a more sensitive biomarker detection method. Additional testing is needed to establish frequency of positive MC1R imaging in stage IV melanoma and its correlation to histological findings and treatment outcomes. Preferential tumor retention provides proof-of-concept that the MC1R-targeting therapy trial for [212Pb]VMT01 alpha-emitting therapy will deliver localized radiation to high MC1R expressing tumors as screened by [203Pb]VMT01 or [68Ga]VMT02. Imaging quality is sufficient for subject selection and dosimetry but may exclude subjects with MC1R receptor expression only detectable by IHC. Citation Format: Brenna M. Marks, Matthew Block, Geoffrey B. Johnson, Carrie B. Hruska, Mukesh K. Pandey, Andrew Paulsen, Michael K. Schultz, Michael A. McDonald, Edwin A. Sagastume, Frances L. Johnson. MC1R imaging and histology in the targeted imaging of melanoma for alpha-particle radiotherapy (TIMAR1) trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr CT104.

Abstract Purpose: Mucosal melanoma is a rare, aggressive form of melanoma with extremely high recurrence rates despite definitive surgical resection with curative intent. Currently there is no consensus on adjuvant therapy. Data on checkpoint inhibitors for adjuvant therapy are lacking. Patients and Methods: We performed a single-arm, multicenter clinical trial using “flip dose” ipilimumab (1 mg/kg q3w × 4 cycles), and nivolumab (3 mg/kg q3w × 4 cycles), then nivolumab 480 mg q4w × 11 cycles to complete a year of adjuvant therapy. Participants must have had R0/R1 resection ≤90 days before registration, no prior systemic therapy (adjuvant radiotherapy allowed), ECOG 0/1, and no uncontrolled autoimmune disease or other invasive cancer. Patients were recruited through the Midwest Melanoma Partnership/Hoosier Oncology Network. Results: From September 2017 to August 2021, 35 patients were enrolled. Of these, 29 (83%) had R0 resections, and 7 (20%) received adjuvant radiotherapy. Median age was 67 years, 21 (60.0%) female. Recurrence-free survival (RFS) rates at 1 and 2 years were 50% [95% confidence interval (CI), 31%–66%] and 37% (95% CI, 19%–55%), respectively. Overall survival rates at 1 and 2 years were 87% (95% CI, 68%–95%) and 68% (95% CI, 46%–83%), respectively. Median RFS was 10.3 months (95% CI, 5.7–25.8). Most common grade 3 toxicities were diarrhea (14%), hypertension (14%), and hyponatremia (11%), with no grade 4/5 toxicities. Conclusions: Flip-dose ipilimumab and nivolumab after resection of mucosal melanoma is associated with outcomes improved over that of surgical resection alone. Long-term follow-up, subgroup analyses and correlative studies are ongoing.

Abstract Background: Better understanding of prognostic factors in tubo-ovarian high-grade serous carcinoma (HGSC) is critical, as diagnosis confers an aggressive disease course. Variation in tumor DNA methylation shows promise predicting outcome, yet prior studies were largely platform-specific and unable to evaluate multiple molecular features. Methods: We analyzed genome-wide DNA methylation in 1,040 frozen HGSC, including 325 previously reported upon, seeking a multi-platform quantitative methylation signature that we evaluated in relation to clinical features, tumor characteristics, time to recurrence/death, extent of CD8+ tumor-infiltrating lymphocytes (TIL), gene expression molecular subtypes, and gene expression of the ATP-binding cassette transporter TAP1. Results: Methylation signature was associated with shorter time to recurrence, independent of clinical factors (N = 715 new set, hazard ratio (HR), 1.65; 95% confidence interval (CI), 1.10–2.46; P = 0.015; N = 325 published set HR, 2.87; 95% CI, 2.17–3.81; P = 2.2 × 10−13) and remained prognostic after adjustment for gene expression molecular subtype and TAP1 expression (N = 599; HR, 2.22; 95% CI, 1.66–2.95; P = 4.1 × 10−8). Methylation signature was inversely related to CD8+ TIL levels (P = 2.4 × 10−7) and TAP1 expression (P = 0.0011) and was associated with gene expression molecular subtype (P = 5.9 × 10−4) in covariate-adjusted analysis. Conclusions: Multi-center analysis identified a novel quantitative tumor methylation signature of HGSC applicable to numerous commercially available platforms indicative of shorter time to recurrence/death, adjusting for other factors. Along with immune cell composition analysis, these results suggest a role for DNA methylation in the immunosuppressive microenvironment. Impact: This work aids in identification of targetable epigenome processes and stratification of patients for whom tailored treatment may be most beneficial.

Most gene-based severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines are nonreplicating vectors. They deliver the gene or messenger RNA to the cell to express the spike protein but do not replicate to amplify antigen production. This study tested the utility of replication in a vaccine by comparing replication-defective adenovirus (RD-Ad) and replicating single-cycle adenovirus (SC-Ad) vaccines that express the SARS-CoV-2 spike protein. SC-Ad produced 100 times more spike protein than RD-Ad and generated significantly higher antibodies against the spike protein than RD-Ad after single immunization of Ad-permissive hamsters. SC-Ad–generated antibodies climbed over 14 weeks after single immunization and persisted for more than 10 months. When the hamsters were challenged 10.5 months after single immunization, a single intranasal or intramuscular immunization with SC-Ad-Spike reduced SARS-CoV-2 viral loads and damage in the lungs and preserved body weight better than vaccination with RD-Ad-Spike. This demonstrates the utility of harnessing replication in vaccines to amplify protection against infectious diseases.