SEMA4D antibody blockade overcomes mechanisms of immune suppression and combination immunotherapy
including TGFβ blockade promotes efficient tumor regression | P478 |
Elizabeth E. Evans, Terrence L. Fisher, Crystal Mallow, Holm Bussler, Sebold Torno, Desa Rae Pastore, Alan Howell, Luis Ruffolo*, Nicholas Ullman*, Benjamin Dale*, Brian Belt*, Joe Bucukovski, Christine | eevans@vaccinex.com |
Reilly, Ernest Smith, David C. Linehan, Maurice Zauderer. | Vaccinex and *University of Rochester, Rochester, New York |
Summary
Immune Checkpoint Combinations
TGFβ Combinations
CLASSICAL-Lung Phase 1/2b Trial: Combination with Avelumab
Background: Despite progress of immune checkpoint blockade therapies, resistance mechanisms including myeloid suppression and upregulation of TGFβ signaling prevent durable clinical benefit in many cancer patients. Anti-semaphorin 4D (SEMA4D, CD100) blocking antibody promotes immune infiltration, reduces immunosuppression, and enhances T cell activity in the tumor microenvironment (TME), resulting in increased tumor control when combined with various immunotherapies in preclinical models (1-3). Clinical trials of immune checkpoint inhibitors (ICI) in combination with pepinemab (VX15/2503), a humanized anti-SEMA4D antibody (4,5), are currently underway in several cancer indications.
Methods: Activity of anti-SEMA4D antibody in combination with immune checkpoint inhibitors and TGFβ blockade was evaluated in preclinical mouse tumor models. Ongoing clinical trials of immune checkpoint inhibitors (ICI) in combination with pepinemab include: (i) a Phase 1b/2a combination trial of pepinemab with avelumab in ICI naïve or ICI refractory or relapsed NSCLC (CLASSICAL-Lung) (NCT03268057, N=65); (ii)
C. | ||
A. Colon26: anti-CTLA-4 Combination | Colon26: anti-LAG3 Combination |
B. | D. | ||
MOC1 HNSCC: anti-CTLA-4 Combo | Colon26: anti-PD-1 Combination | ||
This ongoing completely enrolled phase 1b/2, open label, single arm, first-inhuman combination study is designed to evaluate the combination of pepinemab with avelumab in 62 subjects (pts) with advanced (stage IIIB/IV)
NSCLC.
Study Design
- The trial is split into dose escalation (n=12) and dose expansion (n=50) phases.
- The dose escalation portion includes subjects who are immunotherapy naïve and have either progressed or declined standard first or second-line systemic anticancer therapy.
- Subjects in the three dose escalation cohorts received ascending doses of pepinemab (5, 10, 20 mg/kg, Q2W) in combination with avelumab (10mg/kg, Q2W).
- The expansion phase includes an IO naïve (ION) cohort as well as a second cohort of
Phase 1b | Phase 2 |
Dose Escalation | Dose Expansion |
(n=12) | (n=50) |
pepinemab + 10 mg/kg avelumab, Q2W | |
IO Naive | |
5 mg/kg | IO Failure |
(n=3) | |
10 mg/kg | |
10 mg/kg | (n=32) |
neoadjuvant integrated biomarker trials in patients with metastatic melanoma (NCT03769155, n=36), metastatic colorectal, pancreatic (NCT03373188, n=32) and head and neck (NCT03690986, n=36) cancers treated with pepinemab in combination with nivolumab or ipilimumab.
Results: Anti-SEMA4D antibody enhanced tumor regression when combined with antibodies targeting CTLA-4,PD-1,PD-L1, LAG3, and TGFβ in several preclinical models. For example, anti-SEMA4D plus anti-TGFβ treatment resulted in maximal tumor growth delay (TGD) of 239% (p<0.01) and 10/15 complete tumor regressions (CR) (p<0.05), compared to 10% TGD and 0/13 CR with single agent anti-TGFβ or 29% TGD and 1/10 CR with anti-SEMA4D alone in MC38 colon carcinoma model. Additionally, the combination
3 | Control | ||||||
mm | |||||||
1000 | aSEMA4D | 0.3423 | 0. | ||||
volume | |||||||
aPD-1 + CTRL | 0.0599 | ||||||
aPD-1 + aSEMA4D | 0.0030 | ||||||
Mean Tumor | |||||||
500 | * | ||||||
0 | |||||||
0 | 20 | 40 | 60 | 80 | |||
Day of Study | |||||||
Immunomodulatory effects of SEMA4D blockade can enhance immune checkpoint therapies. A,C,D. Colon26 (500,000 cells) were | Immunomodulatory effects of SEMA4D blockade can enhance TGFβ blockade. A) Colon26 (500,000 cells) were subcutaneously | ||||||
subjects whose tumors progressed during or following immunotherapy (IO failure, IOF).
Study Objectives
- The primary objective is safety, tolerability, and identification of the RP2D for dose expansion.
- Secondary objectives include evaluation of efficacy, immunogenicity, and PK/PD, and an exploratory objective is to identify candidate biomarkers of activity
See POSTER P414
(n=6) | IO Naive |
20 mg/kg | 10 mg/kg |
(n= 18) | |
(n=3) | |
ENROLLMENT COMPLETE
of anti-SEMA4D, folfirinox, and ICI improved survival in KP2-tumor bearing mice, a KPC- derived pancreatic adenocarcinoma model of immune exclusion, myeloid suppression and active TGFb signaling. In clinical trials, pepinemab was well-tolerated and analysis of pre and on-treatment biopsies revealed increased CD8 density and reduced presence of myeloid derived suppressor cells within TME.
subcutaneously implanted into Balb/c mice, that were then treated with αSEMA4D / MAb67 (10 mg/kg, weekly IP X4), αLAG3/C9B7W | implanted into Balb/c mice, that were then treated with αSEMA4D / MAb67 (10 mg/kg, weekly IP X4) and αTGFβ/Mab1D11.16.8 (5 |
(10 mg/kg 2x/week X4; n=20); αCTLA-4 / MAb UC10-4F10 (100/50/50 µg, q3 days; n=20), αPD-1 / MAb RMP1-14 (10 mg/kg, | |
mg/kg, 2x/week IP); n=15. B) MC38 (80,000 cells) were subcutaneously implanted into C57Bl/6 mice, that were then treated with | |
twice/week, starting on day10, n=20), B. MOC1 HNSCC (5x106 cells) were subcutaneously implanted into C57Bl/6 mice, that were | |
αSEMA4D/MAb67 (10 mg/kg, weekly IP) and αTGFb/Mab1D11.16.8 (10 mg/kg, 3x/week IP); n=15. | |
then treated with αSEMA4D/MAb67 (10 mg/kg, weekly IP), αCTLA-4 / MAb 9H-10 (5 mg/kg, q5D); n=10. | |
Integrated Biomarker Window of Opportunity Clinical Study
In collaboration with Winship Cancer Institute, Emory University
Conclusions: SEMA4D antibody blockade modulates the TME to enhance anti-tumor immunity and combination therapies further enhance anti-tumor activity and overcome important resistance mechanisms. Preliminary data suggest the combination of pepinemab plus immune checkpoint therapy is well tolerated and shows initial signals of antitumor activity in patients. Ongoing analysis of various therapeutic combinations and immunophenotyping of tissue biopsies will shed light on mechanism of action of SEMA4D antibody blockade in several combination therapies.
Anti-SEMA4D Mab blocks binding to its cognate receptors
- receptor-mediatedsignaling activity
- Promotes infiltration of potent APC and T cells into TME
- Inhibits function of MDSC, M2 TAM and Treg
FORWARD LOOKING STATEMENT: To the extent that statements contained in this presentation are not descriptions of historical facts regarding Vaccinex, Inc. ("Vaccinex," "we," "us," or "our"), they are forward-looking statements reflecting management's current beliefs and expectations. Words such as "may," "will," "expect," "anticipate," "estimate," "intend" and similar expressions or their negatives (as well as other words and expressions referencing future events, conditions, or circumstances) are intended to identify forward-looking statements. No representations or warranties are offered in connection with the data or information provided herein. This presentation is intended for informational purposes only and may not be relied on in connection with the purchase or sale of any security. Any offering of our securities will be made, if at all, only upon the registration of such securities under applicable securities laws or pursuant to an exemption from such requirements.
Anti-SEMA4D Mab neutralizes SEMA4D barrier at tumor
margin and shifts the balance of tumor immunity
A. Sema4D | B. Increased infiltration of pro-inflammatory APC | C. Shift in balance of tumor | |
gradient | and CD8+ T cells | immunity in TME | |
Vessel | Tumor-specific Cytotoxic T Cells | ||
Ig | |||
Control | %CD3+CD8+ | IFNg ELISPOT | |
Tumor | |||
Anti-SEMA4D enhances T cell infiltration and reduces immunosuppressive M2 TAM in TGFβ driven, highly desmoplastic and immune excluded pancreatic cancer model
(6). A) C57b/6 mice were injected orthotopically with KP2 cells* (derived from the spontaneous KRASG12D; TP53Flox/Wt; P48-Cre autochthonous tumors from David Denardo, Washington University) and treated with αSEMA4D / MAb67, αPD1/MAb RMP1- 14, αCTLA-4 /MAbUC10-4F10 (10 mg/kg, twice weekly IP). Tumors were harvested after 2 weeks of treatment, weighed and dissociated for flow cytometric analysis of CD8+ T cells and M2 TAM.
Fixed Time Point Tumor Weights | Fixed Time Point CD8s | Fixed Time Point TAMs | ||||||||||||
0.4 | p=0.16 | ✱ | ||||||||||||
20 | ✱ | |||||||||||||
✱ | 40 | P=0.16 | ||||||||||||
weightTumor(g) | 0.3 | 3500CD8/CD45 | F4/80+MHCII/CD45 | |||||||||||
15 | 30 | |||||||||||||
0.2 | TGFb1 | TGFb2 | ||||||||||||
10 | 20 | |||||||||||||
4000 | 250 | |||||||||||||
0.1 | 5 | 10 | 200 | |||||||||||
Counts | ||||||||||||||
0.0 | 0 | Counts | 150 | |||||||||||
3000 | ||||||||||||||
100 | ||||||||||||||
2500 | 50 | |||||||||||||
Vehicle | ICB + Vehicle | anti-SEMA4D + Vehicle | anti-SEMA4D + ICB | |||||||||||
2000 | CTRL | SEMA | CTLA | COMBO | 0 | CTRL | SEMA | CTLA | COMBO | |||||
-1.05X | 1.17X* | 1.15X | 1.18X | 1.22X | 1.09X | |||||||||
p=0.432 | p=0.014 | p=0.181 | p=0.301 | p=0.178 | p=0.51 |
Counts
Pepinemab facilitates T cell infiltration into
immune excluded MSS metastatic CRC
No treatment | Pepinemab |
1000 | Normal |
800 | liver |
600 | |
400 | Tumor |
200 | |
Bed | |
0 |
Resectable PDAC | ||
Resectable melanoma | Resectable HNSCC | (n=16) |
CRC resectable liver | ||
(n=36) | (n=36) | |
Currently enrolled:12 | Currently enrolled: 10 | mets (n=16) |
Currently enrolled: 5 | ||
CRC, 1 PDAC | ||
No treatment (SOC) | No Treatment (SOC) | No treatment (SOC) |
VX15/2503 (15 mg/kg) | VX15/2503 (20 mg/kg) | |
VX15/2503 (20 mg/kg) | VX15/2503 (20 mg/kg) | |
VX15/2503 (15 mg/kg) | Ipilimumab (1 mg/kg) | |
Ipilimumab (3 mg/kg) | VX15/2503 (20 mg/kg) | |
VX15/2503 (20 mg/kg) | ||
SEMA4D | CD11c | F4/80 | CD8 | |
67 | ||||
MAb | M2-TAM | MDSC | ||
αSEMA4D | Tumor | |||
SEMA4D is strongly expressed at the invasive margin of tumors. Antibody blockade of SEMA4D facilitates migration of APCs and T cells into the TME. (A) SEMA4D expression at invasive tumor margin restricts infiltration of PLXNB1+ DC into TME. Brackets indicate area of SEMA4D gradient. (B) Anti-SEMA4DMAb treatment promotes infiltration of pro-inflammatory CD11c+/F4-80+antigen presenting cells, while reducing CD206+ M2 macrophage and MDSC. Pro-inflammatoryAPC recruit and activate CD8+ T cells within TME. Colon26 tumor-bearingmice were treated with Control Ig or anti-SEMA4D/MAb67antibodies (50 mg/kg, weekly IP). Tumors were harvested on day 27 and FFPE sections were stained by IHC or (C) tumors were dissociated and assessed for immune cell markers by flow cytometry. Leukocytes were enriched from whole tumor digests using lympholyte-Mand cultured for 2-daysand supernatants were assessed for T cell activity by ELISPOT, n=8-12mice/group.
TGFbRI | TGFbRII | |||||||
Anti-SEMA4D enhances expression of TGFbRII. Upregulation of TGF receptor | ||||||||
5000 | 8000 | * | * | |||||
may result from down-regulation of its ligand, or upregulation of an independent | ||||||||
immune resistance mechanism. Upregulation of TGFbRII4000 | is associated with APC- | 6000 | ||||||
independent and fibroblast-dependent resistance to3000immune checkpoint therapy | Counts | |||||||
and EMT has | 4000 | |||||||
2000 | ||||||||
(7). Potential interaction of SEMA4D/PLXN and TGFCounts β pathways | ||||||||
1000 | 2000 | |||||||
been reported (8,9); further investigation in ongoing. | ||||||||
Colon26 tumor bearing mice were treated as above. 0Tumors were harvested on | 0 | |||||||
CTRL SEMA | CTLA | COMBO | CTRL | SEMA | CTLA | COMBO | ||
day15 and RNA expression was analyzed using Nanostring. | ||||||||
-1.16X | -1.03X | -1.1X | 1.33X | 1.18X | 1.54X | |||
p=0.482 | p=0.879 | p=0.575 | p=0.016 | p=0.261 | p=0.036 | |||
Overcoming Immune Exclusion in TME can | ||||||||
enhance immune checkpoint therapy by | ||||||||
• | Reduction and polarization of suppressive | |||||||
myeloid cells | ||||||||
• Reduction of fibroblast-specificTGF-β | ||||||||
TGFb blockade | signaling (9) | |||||||
MDSC (S100A9+CD33+)
CD8+ T cells
Tumors (Cytokeratin+)
CD8 Density in Tumor Bed | M-MDSC Density in Tumor Bed | |||||||||
25 | 30 | |||||||||
Bed | 20 | cells | Bed | |||||||
llsCeCD8+# mmper | +CD33+S100A9# | mmper | 20 | |||||||
orTum | 15 | rTumo | ||||||||
2 | 10 | 2 | ||||||||
10 | ||||||||||
5 | ||||||||||
0 | 0 | |||||||||
no treatment pepinemab | No treatment | pepinemab | ||||||||
VX15/2503 (20 mg/kg) | Nivolumab (480 mg) | Ipilimumab (1 mg/kg) | |
Nivolumab (480 mg) | Nivolumab (480 mg) | ||
VX15/2503 (15 mg/kg) | VX15/2503 (20 mg/kg) | ||
Nivolumab (3 mg/kg) | |||
Ipilimumab (1 mg/kg) | Nivolumab (480 mg) | ||
Ipilimumab (1 mg/kg) | |||
2 Doses | 1 Dose | 1 Dose | |
Pre-treatment | Surgical | ||
Biopsy | Resection | ||
Biomarker Analysis: | |||
EVALUATE | Safety: | • Compare relative to baseline biopsy and | |
among Rx cohorts | |||
PK/PD | |||
• immune profile in tumor and peripheral blood | |||
* Total enrolled, as of NOV 1, 2019.
D. | MDSC Recruitment | E. MDSC Function | MDSC recruitment and suppressive function is | ||
CXCL1 | CXCL2 | CXCL5 | reversed by SEMA4D antibody blockade. (D) |
Anti-SEMA4D facilitates infiltration of |
T cells and pro-inflammatory APC into TME |
CRC patients received neoadjuvant chemotherapy
before immunotherapy and surgery
The key observations relate to distribution of T cells and MDSC in MSS metastatic CRC. Surgical resections were analyzed from one CRC
In vitro tumor
CTRL αS4D CTRL αS4D CTRL αS4D
MOC1 HNSCC cells in vitro were exposed to Sema4D mAb (10 µg/mL) or isotype for 24 hours and analyzed for myeloid chemokine expression by qRT-PCR (in vitro tumor). Mice bearing MOC1 tumors were treated in vivo with isotype control or anti-Sema4D Ab (αS4D) (n=5/group). Whole tumor digests were analyzed for myeloid chemokine expression via qRT-PCR (whole tumor). (E) MDSC were isolated from HNSCC MOC1 in vivo tumors and co- cultured ex vivo with rSEMA4D (10 μg/ml) or antibodies, in presence of naïve T cells labeled with CFSE in a T cell suppression assay.
and reverses recruitment and activity of | ||
MDSC and M2 TAM. | ||
TGFβ represents | an independent | |
fibroblast-driven mechanism of immune | ||
exclusion and resistance to immune | ||
checkpoint therapy. | ||
Anti-SEMA4D can enhance activity of both | ||
immune checkpoint and TGFβ blockade. | ||
Targeting multiple | pathways may | |
Adapted from: | overcome immune exclusion and promote | |
Evans EE, Paris M, Smith ES & Zauderer M. 2015, OncoImmunology | anti-tumor immunity. | |
patient following 3-5 weeks of treatment with pepinemab and one patient who did not receive antibody treatment. 5 micron FFPE sections were stained sequentially for each marker and scanned at 40X. Scans were co-registered for each stain in multiplex. A) ) CD8+ T cells (red) overlays on cytokeratin stain (green) at tumor/normal liver margin are shown (3.3x). 10x images from center of tumor are shown below with S100A9+/CD33+ MDSC (blue) overlays on cytokeratin stain (green) are shown. B) Total number of CD8 or MDSC cells were quantified from entire tumor bed area, normalized by area of tumor bed using Visiopharm software, and 2 sections/patient were averaged in bar graphs.
Analysis of additional patient samples is ongoing.
REFERENCES: | 5. | Fisher et al, 2016. MAbs. 8(1): 150-162. |
1.Clavijo PE et al. Cancer Immunol Res. 2019 ;7(2):282-291 | 6. | Jiang H, DeNardo et al. Gut. 2019 |
2.Evans, EE et al 2015. Cancer Immunol Res. 3(6):689-701. | 7. | Ganesh K and Massague J. Immunity 48:626-628. 2018 |
3.Evans EE, Paris M, Smith ES & Zauderer M. 2015: OncoImmunology | 8. | Chen Y. Cell Mol Biol Lett. 2018;23. |
4.Patnaik A et al. Clin Cancer Res. 2016;22(4):827-36. | 9. | Zhang C. Cancer Lett. 2019 Jul 2 |
CTRL αS4D CTRL αS4D CTRL αS4D
Attachments
- Original document
- Permalink
Disclaimer
Vaccinex Inc. published this content on 09 November 2019 and is solely responsible for the information contained therein. Distributed by Public, unedited and unaltered, on 09 November 2019 13:14:05 UTC