Rubius Therapeutics (United States)

ABSTRACTMSDC‐0602 K is a second‐generation insulin sensitizer that inhibits the mitochondrial pyruvate carrier without activating the transcription factor PPARγ. The EMMINENCE phase IIb trial evaluated MSDC‐0602 K in patients with metabolic dysfunction‐associated steatohepatitis (MASH). MSDC‐0602 K missed statistical significance on endpoints based on liver histology while producing significant reductions in metabolic biomarkers. Here, we assessed the extracellular matrix‐based biomarkers PRO‐C3 and PRO‐C6, surrogates of collagen type III synthesis and the profibrotic, pro‐inflammatory fragment endotrophin. 392 MASH patients were randomised to placebo (PL), 62.5 mg, 125 mg or a 250 mg daily dose of MSDC‐0602 K for 12 months. 334 completed the study. The primary efficacy endpoint was defined as an improvement of ≥ 2 points in NAS score, with ≥ 1 decrease in either ballooning or inflammation and no increase in fibrosis stage. Blood samples were collected at baseline, 6 months, and 12 months to assess biochemical markers PRO‐C3 and PRO‐C6. The 125 mg and 250 mg doses of MSDC‐0602 K reduced PRO‐C3 at 6 months (p = 0.0103 and p = 0.026 respectively) and 12 months (p = 0.0274 and p = 0.0311) compared to placebo. Furthermore, the 62.5 mg and 250 mg doses reduced PRO‐C6 at 12mo (p = 0.0467 and p = 0.0266) compared to placebo. Treated patients who reached the primary endpoint had lower baseline PRO‐C3 (p = 0.026), and PRO‐C3 levels discriminated between regressing, stable or progressing fibrosis (p = 0.0076). MSDC‐0602 K significantly reduced PRO‐C3 and PRO‐C6, suggesting anti‐fibrotic and pro‐metabolic effects. Lower baseline fibroblast activity (PRO‐C3) at baseline was associated with improvement in fibrosis, while higher baseline PRO‐C3 was associated with fibrosis progression. Our findings suggest that MSDC‐0602 K has anti‐fibrogenesis and pro‐metabolic effects not detected by liver histology.Trial Registration: EMMINENCE clinical trial number (ClinicalTrials.gov NCT02784444)

<div>Abstract<p>Purpose: Treatments are limited for metastatic melanoma (MM) and triple-negative breast cancer (mTNBC). This pilot phase I trial (NCT03060356) examined the safety and feasibility of intravenous RNA- electroporated chimeric antigen receptor (CAR) T cells targeting the cell-surface antigen cMET. Patients and Methods: MM or mTNBC subjects had at least 30% tumor expression of cMET, measurable disease and progression on prior therapy. Patients received up to 6 infusions (1x10e8 T cells / dose) of CAR T cells without lymphodepleting chemotherapy. Forty-eight percent of prescreened subjects met the cMET expression threshold. Seven (3 MM, 4 mTNBC) were treated. Results: Mean age was 50 years (35-64); median ECOG 0 (0-1); median prior lines of chemotherapy/immunotherapy were 4/0 for TNBC and 1/3 for melanoma subjects. Six patients experienced grade (G) 1 or 2 toxicity. Toxicities in at least 1 patient included anemia, fatigue and malaise. One subject had grade 1 cytokine release syndrome. No G 3 or higher toxicity, neurotoxicity, or treatment discontinuation occurred. Best response was stable disease in 4 and disease progression in 3 subjects. Messenger RNA signals corresponding to CAR T cells were detected by RT-PCR in all patients’ blood including in 3 subjects on Day +1 (no infusion administered on this day). Five subjects underwent post-infusion biopsy with no CAR T cell signals seen in tumor. Three subjects had paired tumor tissue; immunohistochemistry showed increases in CD8 and CD3 and decreases in pS6 and Ki67. Conclusions: Intravenous administration of RNA-electroporated cMET-directed CAR T cells is safe and feasible.</p></div>

Insulin sensitizers and incretin mimetics are antidiabetic agents with vastly different mechanisms of action. Thiazolidinedione (TZD) insulin sensitizers are associated with weight gain, whereas glucagon-like peptide-1 receptor agonists can induce weight loss. We hypothesized that combination of a TZD insulin sensitizer and the glucagon-like peptide-1 receptor agonist liraglutide would more significantly improve mouse models of diabetes and nonalcoholic steatohepatitis (NASH). Diabetic db/db and MS-NASH mice were treated with the TZD MSDC-0602K by oral gavage, liraglutide (Lira) by s.c. injection, or combination 0602K+Lira. Lira slightly reduced body weight and modestly improved glycemia in db/db mice. Comparatively, 0602K-treated and 0602K+Lira-treated mice exhibited slight weight gain but completely corrected glycemia and improved glucose tolerance. 0602K reduced plasma insulin, whereas Lira further increased the hyperinsulinemia of db/db mice. Surprisingly, 0602K+Lira treatment reduced plasma insulin and C-peptide to the same extent as mice treated with 0602K alone. 0602K did not reduce glucose-stimulated insulin secretion in vivo, or in isolated islets, indicating the reduced insulinemia was likely compensatory to improved insulin sensitivity. In MS-NASH mice, both 0602K or Lira alone improved plasma alanine aminotransferase and aspartate aminotransferase, as well as liver histology, but more significant improvements were observed with 0602K+Lira treatment. 0602K or 0602K+Lira also increased pancreatic insulin content in both db/db and MS-NASH mice. In conclusion, MSDC-0602K corrected glycemia and reduced insulinemia when given alone, or in combination with Lira. However, 0602K+Lira combination more significantly improved glucose tolerance and liver histology, suggesting that this combination treatment may be an effective therapeutic strategy for diabetes and NASH.

Recombinant agonists that activate co-stimulatory and cytokine receptors have shown limited clinical activity perhaps due to 1) toxicity; 2) a need for coordinated activation of co-stimulatory and cytokine pathways; or 3) the failure of agonist antibodies to recapitulate signaling by endogenous ligands. To address these limitations, Rubius Therapeutics developed genetically engineered red cells with cell surface expression of both co-stimulatory and cytokine ligands, which present ligands in their native form through cell-cell contact to potently activate and expand both T and NK cells. On-target, off-tissue toxicity may be limited due their biodistribution, which is restricted to the vascular system. IL-15 is known to promote NK survival and CD8 T cell memory and 4-1BB agonists are known to promote T cell prolioferation and survival. Rubius Therapeutics has developed RTX-212, an allogeneic red cell therapeutic genetically engineered to co-express 4-1BBL and an IL-15/IL-15Rαfusion (IL-15TP). In vitro assays demonstrated that the combination of both ligands on RTX-212 expanded both memory CD8 T cells (2.5-fold) and NK cells (10-15-fold), in the absence of TCR stimulation. RTX-212 further induced dramatic proliferation of CD8 T cells and CD4 T cells in the presence of TCR stimulation with increased IFNγsecretion. In addition to the synergistic effects of 4-1BBL and IL-15TP, each molecule provided complementary functions that expanded the activity of RTX-212 beyond RTX-4-1BBL or RTX-IL-15TP alone. IL-15TP uniquely activated NK cytotoxicity and ADCC, while 4-1BBL uniquely stimulated CD4 and CD8 T cell proliferation and production of IFNγ. To evaluate in vivo immune responses, anti-tumor activity and safety, a mouse surrogate therapeutic, mRBC-212, was developed where recombinant Fc-IL-15-sushi and m4-1BBL were chemically conjugated to mouse red blood cells. This surrogate overcame the rapid clearance of human red cells in mice. Intravanous administration of mRBC-212 to C57Bl6 mice that received B16F10 melanoma cells IV, showed a 66% decrease in the number of lung metastases compared to control mice (p=0.0001) and was associated with a significant increase in NK cell infiltration into the lungs (p=0.02). In a CT26 tumor model, mRBC-212 treated mice exhibited 55% tumor growth inhibition, which was accompanied by a 1.7-fold increase in the tumor infiltration of proliferating and cytotoxic CD8 T cells. Mice treated with the highest feasible dose of mRBC-212 showed no change in serum transaminases, infiltration of CD8 T cells and macrophages to the liver or liver inflammation score compared to agonistic 4-1BB antibodies treated mice. Taken together, these data indicate that RTX-212 has the potential to be an effective therapy with an improved safety profile compared to 4-1BB agonist antibodies and IL-15 agonists, supporting its clinical development.Citation Format: Anne-Sophie Dugast, Shannon McArdel, Maegan Hoover, Enping Hong, Shannon Curtis Leonard, Arjun Bollampalli, Douglas C. McLaughlin, Jennifer Mellen, Torben Straight Nissen, Christopher L. Carpenter, Thomas J. Wickham, Sivan Elloul. RTX-212, an allogeneic red cell therapeutic expressing 4-1BBL and IL-15TP, exhibits potent in vitro and in vivo activity and a favorable safety profile [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 3272.

T cell-based therapies have demonstrated efficacy in a small subset of cancers; however, they have the potential to proliferate uncontrollably and manufacturing these therapies at scale has proven difficult. To address this limitation, Rubius Therapeutics has genetically engineered red cells to create allogeneic artificial antigen presenting cells (RCT-aAPCs) that express MHC class I loaded with a tumor specific antigen, together with costimulatory molecules that recapitulate normal APC-T cell interactions. These RCT-aAPC cells are designed to expand and activate tumor-specific T cells already present within the patient, thus eliminating the need to individually manufacture patient-derived T cells. As a proof of principle, red cells were engineered to express mouse MHC class I H-2Kb loaded with OVA 257-264 peptide and murine 4-1BBL. These cells induced in vitroT cell proliferation of OVA antigen-specific OT1 cells, whereas red cells expressing only MHC I or 4-1BBL did not induce proliferation. The RCT-aAPC expanded OT1 cells demonstrated an activated phenotype with increased CD44 expression, secretion of both IFNγ and IL2, as well as antigen-specific tumor killing of EG7.OVA tumor cells. To test in vivo efficacy, a mouse surrogate RCT-aAPC was created using murine red blood cells chemically conjugated with H-2Kb OVA and the m4-1BBL molecule. CellTrace Violet (CTV)-labeled OT1 cells were adoptively transferred into B6 Cd45.1 mice followed by intravenous dosing of the RCT-aAPC several hours later. Significant OT1 proliferation was observed 3-4 days post-dosing as measured by CTV dilution. Administration of a second RCT-aAPC dose at this time drove >200-fold expansion of OT1 cells with a memory-like phenotype in the peripheral blood and secondary lymphoid organs. Using a similar dosing strategy, administration of RCT-aAPC to mice bearing EG7.OVA tumors caused 60% tumor growth inhibition by Day 7 after dosing, which corresponded with the increased expansion of the OT1s. Treatment with RCT-aAPC significantly prolonged survival compared to the control group (p-val = 0.0024). After interacting with RCT-aAPC, antigen-specific T cells, traffic to the lymph nodes and tumor as demonstrated by OT1 presence at these sites. Based on the proof of concept using a murine system, human RCT-aAPCs expressing [human] 4-1BBL and [human] HLA-A2 loaded with an HPV E7 peptide were developed to expand and activate HPV E7-specific T cells. These RCT-aAPC cells activated TCR signaling in primary HPV E7-specific T cells as measured by upregulation of Nur77 expression and in engineered HPV E7-specific TCR Jurkat lines, measured using an NFAT luciferase reporter assay. Further validation of RCT-aAPC is ongoing and will be the focus for future clinical development in patients with HPV-positive cancers. Citation Format: Xuqing Zhang, Shamael R. Dastagir, Naren Subbiah, Mengyao Luo, Vikram Soman, Sneha Pawar, Douglas C. McLaughlin, Nicholas Bayhi, Viral Amin, Torben Straight Nissen, Christopher L. Carpenter, Thomas J. Wickham, Tiffany F. Chen. Engineered red-cell therapeutics (RCT) as artificial antigen presenting cells promotein vivoexpansion and anti-tumor activity of antigen specific T cells [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 3260.