On November 9, 2020 Sensei Biotherapeutics, Inc., a clinical-stage biopharmaceutical company developing next generation immunotherapies for the treatment of cancer and infectious diseases, reported new data from its ongoing Phase 1/2 clinical trial of SNS‑301, Sensei’s lead program from its ImmunoPhage platform, in patients with Locally Advanced Unresectable or Metastatic/Recurrent Squamous Cell Carcinoma of the Head and Neck (SCCHN) (Press release, Sensei Biotherapeutics, NOV 9, 2020, View Source [SID1234570532]). The data were presented in a poster session at the Society for Immunotherapy of Cancer (SITC) (Free SITC Whitepaper)’s (SITC) (Free SITC Whitepaper) 35th Anniversary Annual Meeting.

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"These promising new data build upon the initial safety and efficacy data for SNS-301 in patients with ASPH-positive SCCHN and provide additional confidence that SNS-301, when combined with checkpoint inhibition, has the potential to provide long-term benefit as 2nd and later line treatment for patients," said Marie-Louise Fjällskog, M.D., Ph.D., Chief Medical Officer of Sensei Biotherapeutics. "These results, including a partial response in an advanced SCCHN patient with a PD-L1 negative tumor, as well as translational data demonstrating a shift from an immune desert to an inflamed phenotype, represent a notable achievement for Sensei, further validating our unique phage-based platform approach."

The multi-center Phase 1/2 clinical trial is designed to assess the safety, efficacy and immunogenicity of SNS-301 in SCCHN patients that did not achieve tumor reductions on anti-PD-1/PD-L1 therapy alone. As of the data cutoff date of October 6, 2020, eleven patients were enrolled in the study and enrollment is ongoing. Key highlights from the poster titled "Early Safety and Efficacy of a Phase 1/2 Multi-Center Trial of SNS-301 Added to Pembrolizumab in Patients with Advanced Squamous Cell Carcinoma of the Head and Neck" are:

Disease control in 6 of 9 patients evaluable for efficacy, including:
One patient with PD-L1 negative disease achieved a partial response (PR) with a tumor reduction of 43% at week 12 and was confirmed at week 18. Immunohistochemical staining of this patient’s tumor pre- and post-treatment demonstrated clear increases in CD8 density and PD-L1 expression on CD8 T cells and macrophages. This patient also achieved a clear serological response.
One patient achieved a stable disease (SD) for more than 4 months following progressive disease (PD) after 10 months of PD-1 blockade treatment prior to study entry.
Two patients achieved SD for 36+ weeks.
Of the three patients that had PD as their best response, two had PD on single agent PD1 blockade when entering the study.
SNS-301 was well tolerated with no dose-limiting toxicities and observed adverse events (AEs) have primarily been either Grade 1 or 2 and mostly unrelated to treatment.
Nanostring analysis of tumors from patients with a partial response, stable disease, and progressive disease was generally concordant with clinical effect, including across immune parameters such Th1 markers, IFN-gamma, Granzyme B, and CD8 T cells.
In addition to the new safety and efficacy data presented today, Sensei also presented a trial-in-progress (TIP) poster describing the design of the ongoing Phase 1/2 clinical trial of SNS-301 in combination with pembrolizumab in SCCHN patients.

About SNS-301

SNS-301 is a first-in-class cancer immunotherapy designed to overcome immune tolerance and induce robust and durable antigen-specific humoral and cellular responses. It is a bio-engineered, inactivated bacteriophage virus expressing a fusion protein of native bacteriophage GPD (Glyceraldehyde-3-phosphate dehydrogenase) protein and a selected domain of aspartate β-hydroxylase (ASPH). Expression of ASPH is uniquely upregulated in more than 20 different types of cancer and expression levels in various tumors are generally inversely correlated with disease prognosis. ASPH signaling is related to cancer cell growth, cell motility and invasiveness, occurs through the Notch pathway and is implicated in the epithelial to mesenchymal transition (EMT).

On November 9, 2020 Immune-Onc Therapeutics, Inc. ("Immune-Onc"), a clinical-stage cancer immunotherapy company, reported that it will present preclinical data evaluating IO-108, a novel antagonist antibody targeting the myeloid checkpoint Leukocyte Immunoglobulin-Like Receptor B2 (LILRB2, also known as ILT4) for the treatment of solid tumors, at The Society for Immunotherapy of Cancer (SITC) (Free SITC Whitepaper) 35th Anniversary Annual Meeting & Pre-Conference Programs (SITC 2020). The full meeting takes place virtually November 9-14, 2020 (Press release, Immune-Onc Therapeutics, NOV 9, 2020, View Source [SID1234570531]).

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The poster (Abstract #686) titled, "Preclinical Characterization of a Novel Therapeutic Antibody Targeting LILRB2", will be presented on Thursday, Nov. 12, from 4:50-5:20 p.m. EST and on Saturday, Nov. 14, from 1-1:30 p.m. EST.

"Immune-Onc’s unique scientific insights in myeloid cell checkpoints, with a particular focus on the Leukocyte Immunoglobulin-Like Receptor subfamily B (LILRB), have led to a promising and differentiated immunotherapy pipeline," said Charlene Liao, Ph.D., co-founder and CEO of Immune-Onc. "The preclinical data to be presented at SITC (Free SITC Whitepaper) demonstrate the exciting potential of IO-108, a novel therapeutic agent targeting LILRB2. We look forward to advancing IO-108 into the clinic in 2021 to evaluate its safety and efficacy in patients with solid tumors."

IO-108 binds to LILRB2 with high affinity and specificity and blocks the interaction of LILRB2 with ligands that are involved in cancer-associated immune suppression including HLA-G, ANGPTLs and SEMA4A. In assays with primary cells, IO-108 enhances pro-inflammatory activation of immune cells and induces differentiation of monocytes into activated dendritic cells. In ex vivo functional studies with samples from solid tumor patients, IO-108 reprograms immune suppressive myeloid cells to a pro-inflammatory phenotype, thereby enhancing T-cell activation. Together these data suggest that IO-108 has potential therapeutic benefit in solid tumors not responsive to T-cell checkpoint inhibitors. The company plans to file an Investigational New Drug (IND) application for IO-108 with the U.S. Food and Drug Administration in Q2 2021.

ABOUT LILRB2 (ILT4)

LILRB2, also known as ILT4, is expressed mostly on myeloid cells, including monocytes, dendritic cells, macrophages, and neutrophils. In solid tumors, interaction of LILRB2 with tumor microenvironment (TME) relevant ligands, including HLA-G, ANGPTLs, and SEMA4A, makes myeloid cells pro-tumorigenic (tolerating or promoting tumor growth) and promotes tumor immune evasion.

On November 9, 2020 Silverback Therapeutics, Inc. ("Silverback") ("the Company"), a clinical-stage biopharmaceutical company leveraging its proprietary ImmunoTAC technology platform to develop systemically delivered and tissue-targeted therapeutics, reported that it will present two posters at The Society for Immunotherapy of Cancer (SITC) (Free SITC Whitepaper)’s (SITC) (Free SITC Whitepaper) Annual Meeting from November 9-14, 2020 (Press release, Silverback Therapeutics, NOV 9, 2020, View Source [SID1234570530]).

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Silverback will present a trial-in-progress update on SBT6050-101, a Phase 1/1b dose-escalation and expansion clinical trial in patients with advanced or metastatic HER2-expressing solid tumors. SBT6050, the Company’s lead product candidate, comprises a TLR8 linker-payload conjugated to a HER2-directed monoclonal antibody for tumor-localized activation of myeloid cells. "Patients with HER2-expressing cancers need new therapeutic options after standard therapies fail. Most will not respond to PD-1/PD-L1 inhibitors, and physicians and patients are interested in novel immunotherapy options. The SBT6050-101 trial is the first step forward to assess whether Silverback’s novel approach could benefit patients," said Naomi Hunder, M.D., chief medical officer of Silverback. "In preclinical studies, SBT6050 had a favorable toxicology profile, and induced a broad spectrum of antitumor immune mechanisms." SBT6050-101 is actively enrolling in the US and Australia (ClinicalTrials.gov Identifier: NCT04460456)

In addition, the Company will present preclinical data on SBT6290, its second product candidate comprised of the same TLR8 linker-payload used in SBT6050 conjugated to a Nectin4-specific monoclonal antibody. "Nectin4 is a clinically-validated target that is expressed in subsets of solid tumors including bladder, triple negative breast, head and neck, and non-small cell lung cancers among others," said Valerie Odegard, Ph.D., president & chief scientific officer of Silverback Therapeutics. "We are encouraged by SBT6290’s preclinical profile to date and anticipate submitting an IND for this program in the fourth quarter of 2021."

Details of the poster presentations are as follows. The full abstracts will be made available on the SITC (Free SITC Whitepaper) website on November 9, 2020.

A phase 1/1b study of SBT6050, a HER2-directed monoclonal antibody conjugated to a toll-like receptor 8 agonist, in subjects with advanced HER2-expressing solid tumors
Abstract Number: 317
Virtual Poster Hall
Presenter: Leisha Emens, MD, Ph.D., University of Pittsburgh Hillman Cancer Center
Session Date & Time: Wednesday, Nov. 11, from 5:15-5:45 p.m. EST and Friday, Nov. 13, from 4:40-5:10 p.m. EST
Category: Clinical Trial in Progress

SBT6290, a Systemically Administered Nectin4-Directed TLR8 ImmunoTAC Therapeutic, is a Potent Human Myeloid Cell Agonist For the Treatment of Nectin4-Expressing Tumors
Abstract Number: 712
Virtual Poster Hall
Presenter: Heather Metz, Ph.D., Silverback Therapeutics
Session Date & Time: Thursday, Nov. 12, from 4:50-5:20 p.m. EST and Saturday, Nov. 14, from 1-1:30 p.m. EST
Category: Novel Single-Agent Immunotherapies

On November 9, 2020 4D pharma plc (AIM: DDDD), a pharmaceutical company leading the development of Live Biotherapeutic products (LBPs) – a novel class of drug derived from the microbiome, reported new positive clinical data from two clinical trials of MRx0518, its lead immuno-oncology single strain Live Biotherapeutic candidate (Press release, 4d Pharma, NOV 9, 2020, View Source [SID1234570529]). The data is presented in three posters at the Society for Immunotherapy of Cancer (SITC) (Free SITC Whitepaper) Annual Meeting 2020, November 9-14, 2020.

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The first poster includes the first data presented for MRx0518 as a monotherapy. The results are from the completed Part A of a Phase I trial of MRx0518 in the neoadjuvant setting.
Two further presentations provide updates on the ongoing Phase I/II trial of MRx0518 in combination with Keytruda (pembrolizumab) in patients refractory to checkpoint inhibitors.
4D pharma will also host a virtual key opinion leader (KOL) event to review these data on Wednesday, November 11, 2020 at 1:00pm GMT (8:00am ET).
"The data generated from both our trials of MRx0518 and presented this week at SITC (Free SITC Whitepaper), in monotherapy and combination with an immune checkpoint inhibitor settings, is further evidence of the potential of 4D’s LBPs in oncology. The strong immunological signals of biological activity shown in the monotherapy trial provides further clinical evidence of the role and contribution of MRx0518 to the impressive results we are seeing in combination with Keytruda in an incredibly difficult to treat patient population," said Duncan Peyton, Chief Executive Officer of 4D pharma. "The data also furthers and clarifies our earlier work on the mechanism of action of MRx0518 and, importantly, the activity we are seeing in these patients mirrors the preclinical results, further validating our approach and the MicroRx platform. The data generated from these trials provide us with huge confidence not only with moving forward with MRx0518 as a novel immunotherapy for the treatment of cancer, but also our MicroRx platform. We look forward to advancing our MRx0518 program further into the clinic and we are already enrolling patients into Part B of our Keytruda combination study, including the addition of new tumor type cohorts."

MRx0518 in Neoadjuvant Setting Monotherapy

The ongoing, two-part Phase I study is assessing the safety and tolerability of MRx0518 monotherapy in treatment-naïve subjects undergoing surgical resection of solid tumors. The study is designed to generate paired patient samples at diagnostic biopsy and surgical resection, with an intervening period of MRx0518 monotherapy treatment of two to four weeks.

As of data cut-off at October 10, 2020, 17 patients were evaluable for safety and biomarker analyses.

Immune Modulation Results

Following MRx0518 treatment, relative increases in cytotoxic cells, CD8+ T cells and other immune subsets associated with anti-tumor activity were observed in paired tumor samples.
Upregulation of key immuno-stimulatory anti-tumor cytokines and chemokines, such as IL-12 and CXCL10, was observed in post-treatment plasma samples.
Genomic Modulation Results

Gene expression analysis identified significant expression changes in 98 genes (p<0.05) in paired samples as a result of MRx0518 treatment, including upregulation of pathways associated with antigen presentation, costimulatory signaling, cytokine and chemokine signaling, known to promote anti-tumor immune activity.
Initial Safety Data

MRx0518 monotherapy was generally well-tolerated with no SAEs or grades 3 or 4 toxicities reported.
MRx0518 in Combination with Pembrolizumab – Part A Safety and Efficacy data

The ongoing Phase I/II open-label, two-part clinical trial is evaluating the safety and preliminary efficacy of MRx0518 in combination with pembrolizumab in heavily pre-treated metastatic patients with solid tumors refractory to immune checkpoint inhibitors.

The goal of the Part A phase of this study, which was to assess the safety, tolerability and initial efficacy, enrolled a total of 12 heavily pre-treated metastatic renal cell carcinoma (RCC) and non-small cell lung cancer (NSCLC) patients refractory to immune checkpoint inhibitors. All patients received a twice daily dose of oral MRx0518 for 3 weeks in combination with a single cycle of pembrolizumab, and assessed for dose-limiting toxicities. Once the treatment cycle was completed, patients were eligible to remain on treatment for up to 2 years to assess clinical benefit.

As of the data cut-off date October 23, 2020, all 12 patients enrolled in Part A of this study were evaluable for safety and preliminary efficacy.

Initial Clinical Activity Data

MRx0518 in combination with pembrolizumab provided clinical benefit to 5 of 12 (42%) patients, defined as a complete response (CR), partial response (PR) or stable disease (SD) for 6 months or longer.
Of the 5 patients who achieved clinical benefit, 3 patients experienced PR, an overall response rate (ORR) of 25%. Best overall response to prior to immune checkpoint inhibitor treatment for 2 of these patients was stable disease (SD).
Median progression free survival (PFS) was 2.14 (95% CI 0.43, not estimable) months.
Initial Safety Data

MRx0518 in combination with pembrolizumab was generally well-tolerated with no treatment-related Grades 4 or 5 serious adverse events (SAEs) reported.
No treatment-related adverse events were attributed to treatment discontinuation.
MRx0518 in Combination with Pembrolizumab – Part B Ongoing, Addition of New Cohorts

In addition to the new safety and preliminary efficacy data announced today, 4D also presented a trial-in-progress (TIP) poster describing the ongoing Part B cohort expansion phase of the Phase I/II clinical trial of MRx0518 in combination with pembrolizumab in patients refractory to immune checkpoint inhibitors. Today 4D pharma announced additional tumor type cohorts will be enrolled on the study, following the promising clinical benefit results generated in Part A in patients with RCC and NSCLC.

Part B of this study is currently enrolling up to 120 patients with RCC, NSCLC, bladder cancer, triple-negative breast cancer (TNBC), head and neck squamous cell carcinoma (HNSCC) and microsatellite instability-high/mismatch repair deficient (MSI-H/dMMR) solid tumors. Enrollment is expected to complete Q4 2021.

The clinical data from the two MRx0518 clinical trials presented at the SITC (Free SITC Whitepaper) Annual Meeting are now available on the Posters and Publications section of the 4D pharma website at www.4Dpharmaplc.com.

For more information on the clinical trials see View Source and View Source

Virtual KOL Conference Call and Webcast Event

4D pharma will host a virtual event for investors and analysts to review the data presented from two ongoing clinical trials of MRx0518 at SITC (Free SITC Whitepaper) 2020. The event will take place on Wednesday, November 11, 2020 at 1:00pm GMT (8:00am ET) and will feature discussions of data from both trials from Dr. Mark P. Lythgoe, Academic Clinical Fellow in Medical Oncology and Pharmacist at Imperial College London, and Dr. Shubham Pant, Associate Professor Department of Investigational Cancer Therapeutics and Department of Gastrointestinal Medical Oncology at the University of Texas MD Anderson Cancer Center, as well as presentations from 4D management.

A live webcast of the event will be available on the Reports and Presentations section of the 4D pharma website at www.4Dpharmaplc.com. To access the call, please dial 1-877-270-2148 (United States) or 1-412-902-6510 (international) and reference the 4D pharma conference call to join. A replay of the webcast and accompanying slides will be available on the 4D pharma website following the event.

About MRx0518

MRx0518 is single strain Live Biotherapeutic product in development for the treatment of cancer. It is delivered as an oral capsule and stimulates the body’s immune system, directing it to produce cytokines and immune cells that are known to attack tumours. It is currently being evaluated in three clinical trials in cancer patients. MRx0518-I-001 is a neoadjuvant monotherapy study in a variety of solid tumours and is being conducted at Imperial College (London, UK). MRx0518-I-002 is in combination with KEYTRUDA (pembrolizumab) in patients who have previously progressed on anti PD-1 therapies. The Coordinating Investigator of the study is at The University of Texas MD Anderson Cancer Center, Houston, USA, with multiple additional sites in the US. The study is being conducted in collaboration with MSD, the tradename of Merck & Co., Inc., Kenilworth, NJ, USA. MRx0518-I-003 is in combination with preoperative radiotherapy in resectable pancreatic cancer.

On November 9, 2020 Xencor, Inc. (NASDAQ:XNCR), a clinical-stage biopharmaceutical company developing engineered monoclonal antibodies for the treatment of cancer and autoimmune diseases, reported the presentation of new data from multiple preclinical XmAb bispecific antibody programs and its preclinical IL-12-Fc cytokine program at the 35th Annual Meeting of the Society for Immunotherapy of Cancer (SITC) (Free SITC Whitepaper) (Press release, Xencor, NOV 9, 2020, View Source [SID1234570528]).

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"Our XmAb bispecific Fc domains were specifically created to enable the rapid design and simplified development of a wide range of multi-specific antibodies and other protein structures, such as our engineered cytokines," said John Desjarlais, Ph.D., senior vice president and chief scientific officer at Xencor. "At SITC (Free SITC Whitepaper), we are presenting new data from multiple preclinical programs, including CD28 bispecific antibodies, our second class of T cell engagers, that we have designed to conditionally co-stimulate T cells when they are bound to tumor cells. For the first time, we also show data from two selective TGFβ inhibitors engineered with XmAb bispecific Fc domains."

Poster presentations and audio descriptions are available to registrants of the SITC (Free SITC Whitepaper) Annual Meeting. The posters will also be archived under "Events & Presentations" in the Investors section of the Company’s website located at www.xencor.com.

CD28 Bispecific Antibody Platform

Poster 697, "Tumor-targeted CD28 costimulatory bispecific antibodies enhance T cell activation in solid tumors"
T cells in the tumor microenvironment require both T cell receptor (TCR) and co-stimulatory receptor engagement to achieve full activation. CD28 is a key immune co-stimulatory receptor on T cells; however, the ligands that activate T cells through CD28 are often not expressed on tumor cells. Targeted CD28 bispecific antibodies may provide conditional co-stimulation of T cells, for example, to T cells recognizing neoantigens or in concert with CD3 T-cell engaging bispecific antibodies.

Xencor engineered two XmAb bispecific antibodies, B7-H3 x CD28 and PD-L1 x CD28, to provide conditional co-stimulation of T cells, activating them when bound to tumor cells. B7-H3 is an immune receptor highly expressed on a wide range of solid tumors and has low expression on normal tissue, and it is associated with poor clinical outcomes. PD-L1, which is also expressed on many types of tumors, suppresses anti-tumor responses by the immune system.

The B7-H3 x CD28 bispecific antibody activated T cells only in the presence of the B7-H3 antigen and did not demonstrate super-agonism, consistent with Xencor’s CD28 platform design. The combination of B7-H3 x CD28 and a PSMA x CD3 T cell engaging bispecific antibody generated enhanced T cell activation and proliferation in a PSMA-positive cell line compared to the PSMA x CD3 alone; importantly, no activity was observed in a PSMA-negative cell line, demonstrating that both antigens are required for T cell activation. A combination of B7-H3 x CD28 and a B7-H3 x CD3 bispecific antibody enhanced anti-tumor activity compared to either bispecific antibody alone in an in vivo model of breast cancer.

Further, the combination of the PD-L1 x CD28 and a B7-H3 x CD3 T cell engaging bispecific antibody demonstrated superior T cell activation and proliferation compared to a bivalent anti-PD-L1 antibody and B7-H3 x CD3 combination. In vivo, PD-L1 x CD28 inhibited tumor growth more effectively than a bivalent anti-PD-L1 antibody.

PD-1 x TGFβR2 Bispecific Antibody Program

Poster 714, "PD-1 x TGFβR2 bispecifics selectively block TGFβR2 on PD-1-positive T cells, promote T cell activation, and elicit an anti-tumor response in solid tumors"
TGFβ is an inhibitory cytokine, and its production by solid tumors and the tumor microenvironment is a significant mechanism used by tumors to avoid recognition by the immune system. While TGFβ inhibition is expected to promote an anti-tumor response, systemic blockade of TGFβ has also been associated with toxicity.

Xencor engineered two XmAb bispecific antibodies, PD-1 x TGFβR2 and CD5 x TGFβR2, to selectively block the suppressive activity of TGFβ on specific T-cell populations and to enhance their anti-tumor activity while avoiding the toxicity associated with systemic blockade. PD-1 and CD5 were selected to direct TGFβ blockade to activated or all T cells, respectively.

In vitro, both bispecific antibodies exhibited highly selective blocking of TGFβ activity in PD-1-high and CD5-high T cell populations. Additionally, PD-1 x TGFβR2 was active in vivo and promoted T cell engraftment and anti-tumor response. Anti-tumor activity was enhanced when combined with an anti-PD-1 antibody, compared to anti-PD-1 alone or an anti-PD-L1/TGFβ trap. Similar in vivo evaluation of CD5 x TGFβR2 is underway.

IL-12-Fc

Poster 564, "Potency-reduced and extended half-life IL-12 heterodimeric Fc-fusions exhibit strong antitumor activity with potentially improved therapeutic index compared to native IL-12 agents"
IL-12 is a proinflammatory cytokine produced by activated antigen-presenting cells, and it leads to proliferation of T cells and NK cells and increased cytotoxicity through high levels of interferon gamma signaling. As a potent immune stimulating protein, IL-12 can have a significant effect on shrinking tumors; however, prior clinical studies have demonstrated it to have a narrow therapeutic window, limiting potential response rates.

Xencor’s IL-12-Fc cytokine program builds on Xencor’s prior work with IL-15-Fc fusions in oncology, where reduced potency led to improved pharmacokinetics, pharmacodynamics and safety in preclinical studies. IL-12-Fc fusions were engineered with reduced potency in order to improve potential tolerability, slow receptor-mediated clearance and prolong the fusions’ half-lives in vivo, compared to native IL-12. These potency-reduced IL-12-Fc fusions demonstrated significant anti-tumor activity concurrent with activation and proliferation of CD8+ T cells, increased PD-1 checkpoint expression and increased levels of interferon gamma in serum. Anti-tumor activity was enhanced when combined with an anti-PD-1 antibody.