A fully-closed, high efficiency manufacturing technology platform for the production of T cell therapies targeting multiple tumor antigensChristine M. McInnis*, Amy M. Shaw*, Shawn P. Carey, Jonas Bruun, Rachel Klaski, Pengpeng Cao, Elisabeth Brown, Andy Rakestraw, Becker Hewes, Jonathan Fitzgerald, Thomas L. Andresen, Fabio Fachin. Torque Therapeutics, Cambridge, MA

SITC 2018Annual MeetingNovember 7-11Washington, D.CPresented:November 10, 2018.

BackgroundAdoptive cell therapy (ACT) is a promising approach fortreating tumors refractory to other treatment modalities.ACTs, however, are still largely limited to genetically-modified approaches that recognize a single antigen, requireharsh pre-treatments or adjuvant drugs to enable ACTsurvival and function in vivo, and are often associated withsevere toxicities.

Torque’s Deep-PrimedTM cell therapy platform uses novel cellprocess engineering to generate multi-targeted T cells(MTCs) that recognize multiple tumor antigens and that aretethered to Deep IL-15, a crosslinked multimer of humanIL15-Fc, to deliver directed immune activation in the tumormicroenvironment. Torque’s SlipstreamTM cell process is semi-automated and fully closed, and its modular automationdesign enables both large-scale and decentralizedmanufacturing.

MethodsFollowing apheresis, patients’ T cells and monocytes areenriched, and monocytes are differentiated into peptide-loaded mature dendritic cells (mDC) for presentation toautologous T cells. Antigen-presentingmDC are co-culturedwith T cells, promoting expansion of low-frequency,antigen-specific T cells directed towards multiple tumorassociated antigens (TAA). Following expansion, the multi-targeted T cells are loaded with Deep IL-15,cryopreserved and formulated for multiple infusions.Here, we present product composition, specificity,cytotoxicity, and the advantage of Deep IL-15 acrossdevelopment and GMP lots of MTCs generated from healthydonors.

Results

Conclusions• Slipstream™manufacturing is a semi-automated and fullyclosed system enabling Repeat Dosing Regimen.

• Deep IL-15 Primed Slipstream™ T cells exhibit high post-thaw recovery, viability and stability.

• Deep IL-15 loading drives survival, expansion andreactivity of Slipstream™MTCs.

• Clinical program for TRQ15-01 is expected to start in2018.

Figure 1: Deep IL-15 Provides Autocrine Cytokine Stimulation. Deep IL-15 is a crosslinkedmultimer of human IL15-Fc monomers. IL15-Fc monomers consist of two subunits, each consistingof an effector attenuated IgG-Fc fused with an IL-15 receptor α-sushi-domain noncovalently boundto a molecule of IL-15. Deep IL-15 Primed T cells are generated via a loading process in which cellsare co-incubated with Deep IL-15 at high concentrations.

Surfacemodifier

Cleavable crosslinker

IL15-Fc Deep IL-15

multi-targeted T cell

Deep IL-15

Deep IL-15Primed T Cell

HumanIgG-Fc

Collect cellsIsolate

monocytesMature into

dendritic cellsProprietary

Dendritic cellsGenerate

MTCsTAA-specific

Primed T cells

TAA peptidesApheresis multi-targeted T cells

Deep IL-15 primed MTCs

0(no CTL)

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Figure 3. Phenotyping of SlipstreamTM Manufacturing. (A) Cells stained using a cell identitypanel and quantified using flow cytometry show resultant MTC product has a mean CD3+frequency of 93.1% (+/-6.3%, n=9). (B) Product T cell phenotyping was done via flow cytometryand showed large effector memory and transitional memory populations (n=8). (C)Mean (SD) ofreactivity from harvested Slipstream cells as quantified by CD25 positivity. (D)Mean (SD) of IFN-γ release from harvested antigen reactive SlipstreamTM cells.

SlipstreamTM T cells have high purity, transitional and effector memory phenotype,and antigen-specific reactivity.

Figure 2. Slipstream™ Cell Manufacturing platform is a proprietary, high-efficiency T cellmanufacturing platform engineered to operate as modular compact factories. SlipstreamTMproduction is semi-automated and fully closed, which eliminates contamination risk betweentransfers and can dramatically reduce staffing requirements and the factory footprint.

Slipstream™ Cell Manufacturing produces Deep IL-15 loaded MTCs in 18 days

Product T Cell Phenotype

Figure 8. Targeted killing of tumor cell lines.Deep IL-15 loaded SlipstreamTM cells show MHC:I-restricted cytotoxicity against partially HLA-matched MeWo melanoma line expressing tumor-associated antigens.

Deep IL-15 loaded SlipstreamTM MTCsshow MHC:I restricted cytotoxicity

A C

D

Figure 4. TCR Sequencing of incoming T cells and harvested SlipstreamTM MTCs.Sequencing of incoming T cell-rich fraction and final harvested SlipstreamTM cells reveals that themajority of T cell clones found in the incoming apheresis are no longer detectable in the finalharvested product. The majority of cells found in the harvested product were undetectable in theincoming apheresis, and a minority of clones were detected in both.

SlipstreamTM manufacturing process enriches for rare T cell clones with TCRsequences not detectable in donor apheresis

Lot Number Site

Cell Number at Harvest (x109)

1 PD 11.32 PD 8.13 PD 20.04 PD 20.05 PD 15.36 PD 20.07 GMP 20.08 GMP 15.99 GMP 6.0

Figure 5. Harvest cell number in SlipstreamTM Manufacturing process. (A) MTCsmanufactured across PD and GMP sites resulted in expansions capable of dosing patientsmultiple times. (B) Cell number per dose (based on a 1.7m2 patient) per cohort for TRQ15-01.

All lots made multiple doses for highest cohort and maximum doses for lower cohorts

Figure 6. Post-thaw recovery, viability and stability of Deep IL-15 loading. At thaw, Deep IL-15 loaded SlipstreamTM T cells exhibit good recovery (A) and viability (B). Deep IL-15 loadinglevels on the T cells are stable post-thaw (C).

Deep Il-15 Primed SlipstreamTM T cells exhibit high post-thaw recovery, viability andstability of Deep IL-15 loading

A Cryopreserved Cell Recovery B Post-Thaw Viability

Product Composition

Cohort Level Cells/Dose

Doses Achieved (max 12)1

1 3.4x10712

2 6.8x10712

3 2.0x10812

4 6.1x10812

5 1.7x1099

A BCell Harvest Numbers Across Sites TRQ15-01 Dosing by Cohort(Repeat Dosing Regimen Included in Clinical Design)

B

Detected in Apheresis OnlyShared Between Apheresis and ProductDetected in Product Only

TCR Clones

Apheresis

MTC Product

Lot 4 Lot 5 Lot 6Mean

Antigen Specific Reactivity

IFN-! Release per Reactive Cell

C Deep IL-15 Stability

Figure 7. Effect of Deep IL-15 loading on expansion and viability. Significant differences inpost-thaw expansion (A) and viability (B) are observed between MTCs and Deep IL-15 LoadedMTCs. No additional cytokine support was provided to the culture, with expansion and viabilitylevels being exclusively driven by Deep IL-15 Loading (or lack thereof).

Deep IL-15 loading promotes in vitro expansion and viability of SlipstreamTM T cells

18 Days

SlipstreamTM manufacturing results in high purity, tumor antigen-reactive T cells

Torque's modular antigen-priming process reliably generatesbillions of T cells to obtain multiple drug doses via a singlemanufacturing run. Across donors and across both processdevelopment and GMP sites, Torque's process reliablyexpands endogenous antigen-specific MTCs. The MTCproducts display a mixture of memory and effectorphenotypes, with low expression of exhaustionmarkers. The products are further characterized by aunique signature against multiple TAA epitopes, with a mean11% TAA-reactivity [5-20%]. TCR sequencing reveals that themajority of clones in the final product originate from rareclones, undetectable in the incoming apheresis. Post-thaw,the Deep IL-15 tethered to the MTCs ensures prolongedsurvival, increased expansion, and cytotoxicity againstantigen-expressing cell lines.

TCR sequences from multi-targeted T cell product are highly divergent from apheresis sequences

Tumor cell killing by Deep IL-15 primed multi-targeted T cells

Manufacturing process enables multiple doses

A Post-thaw expansion B Post-thaw viability

SlipstreamTM manufactured T cells exhibit good freeze-thaw stability

SlipstreamTM MTC:Target cell Ratio

1 Doses achieved is calculated based on the average cell number at harvest (15.3x109). A maximum of 12 doses will be harvested for for each cohort.

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