Abstract 5660: IGM-7354, an immunocytokine with IL-15 fused to an anti-PD-L1 IgM, induces NK and CD8+ T cell mediated cytotoxicity of PD-L1-positive tumor cells

Immunostimulatory cytokines are a promising immunotherapy for the treatment of advanced malignancies, but generally have been associated with severe toxicities when administered systemically. The recent development of antibody-cytokine fusion proteins, or immunocytokines, aims to localize cytokine activity to the tumor microenvironment and thus improve their therapeutic index. We have developed IGM-7354, a high affinity, high avidity anti-PD-L1 pentameric IgM antibody with an IL-15Rα chain and IL-15 fused to the joining (J) chain. The IGM-7354 immunocytokine was designed to deliver IL-15-mediated stimulation of NK and CD8+ T cells to PD-L1-expressing tumors and antigen-presenting cells, to enhance anti-tumor immune responses. The multivalent binding of IGM-7354 to PD-L1 provided a stronger binding avidity for human PD-L1 than the monovalent binding of IL-15 to IL-15Rb as confirmed in kinetic binding assays. In vitro IGM-7354 induced the proliferation of a cytotoxic T cell line responsive to IL-15 stimulation and enhanced the proliferation of NK and CD8+ T cells from healthy donor human PBMCs. In cytotoxicity assays with human PBMC and PD-L1+ cancer cell lines, IGM-7354 enhanced cancer cell killing through NK and CD8+ T cell expansion and cytotoxic activity, evidenced by Ki67 and Granzyme B upregulation in these cell populations. Next, in vivo pharmacodynamic studies were performed in two humanized mouse models: non-tumor-bearing BRGSF-HIS mice engrafted with human CD34+ cells, and PD-L1+ MDA-MB-231 tumor-bearing MHC-/- NSG mice engrafted with human PBMCs. In the BRGSF model, IGM-7354 increased NK cell activation and Granzyme B expression as well as NK and CD8+ T cell proliferation. In the tumor-bearing mouse model, IGM-7354 dose-dependently increased NK and CD8+ T cell proliferation in blood and infiltration of lymphocytes into the tumor. This pharmacodynamic activity correlated with IGM-7354 anti-tumor activity in the MDA-MB-231 model. Lastly, IGM-7354 increased the proliferation of NK and CD8+ T cells in cynomolgus monkeys and particularly induced the expansion of effector memory CD8+ T cells in the periphery. In summary, IGM-7354 induces NK and CD8+ T cell proliferation in both in vitro and in vivo preclinical models, resulting in the killing of PD-L1+ tumor cells. The strong avidity of IGM-7354 for PD-L1 may enhance IL-15 delivery to tumors and antigen-presenting cells and thus provide a more favorable safety profile. A Phase 1 clinical trial is planned.

Citation Format: Thierry D. Giffon, Melanie Desbois, Poonam Yakkundi, Susan Calhoun, Keerthana Sekar, Carolyn Denson, Tasnim Kothambawala, Alexander Pearson, Sivani Pandey, Deepal Pandya, Rodnie Rosete, Daniel Machado, Pat Raichlen, Dean Ng, Abhinav R. Jain, Roel Funke, Eric Humke, Paul R. Hinton, Beatrice Wang, Bruce A. Keyt, Maya F. Kotturi, Angus M. Sinclair. IGM-7354, an immunocytokine with IL-15 fused to an anti-PD-L1 IgM, induces NK and CD8+ T cell mediated cytotoxicity of PD-L1-positive tumor cells. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5660.

Non-viral precision T cell receptor replacement for personalized cell therapy

T cell receptors (TCRs) enable T cells to specifically recognize mutations in cancer cells1-3. Here we developed a clinical-grade approach based on CRISPR-Cas9 non-viral precision genome-editing to simultaneously knockout the two endogenous TCR genes TRAC (which encodes TCRα) and TRBC (which encodes TCRβ). We also inserted into the TRAC locus two chains of a neoantigen-specific TCR (neoTCR) isolated from circulating T cells of patients. The neoTCRs were isolated using a personalized library of soluble predicted neoantigen-HLA capture reagents. Sixteen patients with different refractory solid cancers received up to three distinct neoTCR transgenic cell products. Each product expressed a patient-specific neoTCR and was administered in a cell-dose-escalation, first-in-human phase I clinical trial ( NCT03970382 ). One patient had grade 1 cytokine release syndrome and one patient had grade 3 encephalitis. All participants had the expected side effects from the lymphodepleting chemotherapy. Five patients had stable disease and the other eleven had disease progression as the best response on the therapy. neoTCR transgenic T cells were detected in tumour biopsy samples after infusion at frequencies higher than the native TCRs before infusion. This study demonstrates the feasibility of isolating and cloning multiple TCRs that recognize mutational neoantigens. Moreover, simultaneous knockout of the endogenous TCR and knock-in of neoTCRs using single-step, non-viral precision genome-editing are achieved. The manufacture of neoTCR engineered T cells at clinical grade, the safety of infusing up to three gene-edited neoTCR T cell products and the ability of the transgenic T cells to traffic to the tumours of patients are also demonstrated.

Abstract CT250: A Phase 1a/1b, open-label first-in-human study of the safety, tolerability, and feasibility of gene-edited autologous NeoTCR-T cells (NeoTCR-P1) administered to patients with locally advanced or metastatic solid tumors

Introduction: Neoepitopes (neoE) derived from private tumor-exclusive mutations represent compelling targets for personalized TCR-T cell therapy. An ultra-sensitive and high-throughput process was developed to capture tumor mutation-targeted CD8 T cells from patient blood. NeoTCRs cloned from the captured CD8 T cells, when engineered into fresh CD8 and CD4 T cells, effected killing of patients' autologous tumor cells in vitro. These observations have been leveraged for the development of a fully personalized adoptive T cell therapy (NeoTCR-P1). A Phase 1 clinical trial testing NeoTCR-P1 in subjects with solid tumors is ongoing (NCT03970382). Study Design: During the initial trial phase, escalating doses of NeoTCR-P1 T cells administered without and with IL-2 in the regimen, and following conditioning chemotherapy, will be evaluated in subjects with advanced or metastatic solid tumors (melanoma, urothelial cancer, colorectal cancer, ovarian cancer, HR+ breast cancer, and prostate cancer). The objective of the Phase 1a study is to establish a recommended Phase 2 dose. Primary endpoints include the incidence and nature of DLTs and overall process feasibility. The proliferation, persistence, and trafficking of NeoTCR-T cells will be characterized. In the expansion trial phase, preliminary anti-tumor activity of NeoTCR-P1 will be assessed in selected tumors. The combination of NeoTCR-P1 dosing plus nivolumab will be tested in a Phase 1b study. Conclusion: This is the first clinical study of an autologous, fully personalized adoptive T cell therapy directed against private tumor-exclusive mutations, generated without using recombinant viral vectors.

Citation Format: Mihaela Cristea, Bartosz Chmielowski, Roel Funke, Todd Stallings-Schmitt, Mitch Denker, Mark Frohlich, Alex Franzusoff, Mehrdad Abedi, Samuel Ejadi. A Phase 1a/1b, open-label first-in-human study of the safety, tolerability, and feasibility of gene-edited autologous NeoTCR-T cells (NeoTCR-P1) administered to patients with locally advanced or metastatic solid tumors [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT250.

A phase Ia/Ib, open-label first-in-human study of the safety, tolerability, and feasibility of gene-edited autologous NeoTCR-T cells (NeoTCR-P1) administered to patients with locally advanced or metastatic solid tumors

TPS3151

Background: Neoepitopes (neoE) derived from private tumor-exclusive mutations represent compelling targets for personalized TCR-T cell therapy. An ultra-sensitive and high-throughput process was developed to capture tumor mutation-targeted CD8 T cells from patient blood. NeoTCRs cloned from the captured CD8 T cells, when engineered into fresh CD8 and CD4 T cells, effected killing of patients’ autologous tumor cells in vitro. These observations have been leveraged for the development of a fully personalized adoptive T cell therapy (NeoTCR-P1). A Phase 1 clinical trial testing NeoTCR-P1 in subjects with solid tumors is ongoing (NCT03970382). Methods: During the initial trial phase, escalating doses of NeoTCR-P1 T cells administered without and with IL-2 in the regimen, and following conditioning chemotherapy, will be evaluated in subjects with advanced or metastatic solid tumors (melanoma, urothelial cancer, colorectal cancer, ovarian cancer, HR+ breast cancer, and prostate cancer). The objective of the Phase 1a study is to establish a recommended Phase 2 dose. Primary endpoints include the incidence and nature of DLTs and overall process feasibility. The proliferation, persistence, and trafficking of NeoTCR-T cells will be characterized. In the expansion trial phase, preliminary anti-tumor activity of NeoTCR-P1 will be assessed in selected tumors. The combination of NeoTCR-P1 dosing plus nivolumab will be tested in a Phase 1b study. Conclusion: This is the first clinical study of an autologous, fully personalized adoptive T cell therapy directed against private tumor-exclusive mutations, generated without using recombinant viral vectors. Clinical trial information: NCT03970382 .

Atezolizumab Plus nab-Paclitaxel in the Treatment of Metastatic Triple-Negative Breast Cancer With 2-Year Survival Follow-up: A Phase 1b Clinical Trial

Importance

The humanized monoclonal antibody atezolizumab targets programmed death-ligand 1 and has demonstrated durable single-agent activity in a subset of metastatic triple-negative breast cancers. To extend the observed activity, combinatorial approaches are being tested with standard cytotoxic chemotherapies known to induce immunogenic tumor cell death.

Objective

To examine the safety, tolerability, and preliminary clinical activity of atezolizumab plus nab-paclitaxel in metastatic triple-negative breast cancers.

Design, Setting, and Participants

This phase 1b multicohort study enrolled 33 women with stage IV or locally recurrent triple-negative breast cancers and 0 to 2 lines of prior chemotherapy in the metastatic setting from December 8, 2014, to April 30, 2017, at 11 sites in the United States. The median follow-up was 24.4 months (95% CI, 22.1-28.8 months).

Interventions

Patients received concurrent intravenous atezolizumab and intravenous nab-paclitaxel (minimum 4 cycles).

Main Outcomes and Measures

The primary end point was safety and tolerability. Secondary end points included best overall response rate by Response Evaluation Criteria in Solid Tumors, version 1.1; objective response rate; duration of response; disease control rate; progression-free survival; overall survival; and biomarker analyses.

Results

The 33 women had a median age of 55 years (range, 32-84 years) and received 1 or more doses of atezolizumab. All patients (100%) experienced at least 1 treatment-related adverse event, 24 patients (73%) experienced grade 3/4 adverse events, and 7 patients (21%) had grade 3/4 adverse events of special interest. No deaths were related to study treatment. The objective response rate was 39.4% (95% CI, 22.9%-57.9%), and the median duration of response was 9.1 months (95% CI, 2.0-20.9 months). The disease control rate was 51.5% (95% CI, 33.5%-69.2%). Median progression-free survival and overall survival were 5.5 months (95% CI, 5.1-7.7 months) and 14.7 months (95% CI, 10.1-not estimable), respectively. Concurrent nab-paclitaxel neither significantly changed biomarkers of the tumor immune microenvironment (programmed death-ligand 1, tumor-infiltrating lymphocytes, CD8) nor impaired atezolizumab systemic immune activation (expansion of proliferating CD8+ T cells, increase of CXCL10 chemokine).

Conclusions and Relevance

In this phase 1b trial for metastatic triple-negative breast cancers, the combination of atezolizumab plus nab-paclitaxel had a manageable safety profile. Antitumor responses were observed, including in patients previously treated with a taxane.

Trial Registration

ClinicalTrials.gov identifier: NCT01633970.

Atezolizumab and Nab-Paclitaxel in Advanced Triple-Negative Breast Cancer

BACKGROUND

Unresectable locally advanced or metastatic triple-negative (hormone-receptor-negative and human epidermal growth factor receptor 2 [HER2]-negative) breast cancer is an aggressive disease with poor outcomes. Nanoparticle albumin-bound (nab)-paclitaxel may enhance the anticancer activity of atezolizumab.

METHODS

In this phase 3 trial, we randomly assigned (in a 1:1 ratio) patients with untreated metastatic triple-negative breast cancer to receive atezolizumab plus nab-paclitaxel or placebo plus nab-paclitaxel; patients continued the intervention until disease progression or an unacceptable level of toxic effects occurred. Stratification factors were the receipt or nonreceipt of neoadjuvant or adjuvant taxane therapy, the presence or absence of liver metastases at baseline, and programmed death ligand 1 (PD-L1) expression at baseline (positive vs. negative). The two primary end points were progression-free survival (in the intention-to-treat population and PD-L1-positive subgroup) and overall survival (tested in the intention-to-treat population; if the finding was significant, then it would be tested in the PD-L1-positive subgroup).

RESULTS

Each group included 451 patients (median follow-up, 12.9 months). In the intention-to-treat analysis, the median progression-free survival was 7.2 months with atezolizumab plus nab-paclitaxel, as compared with 5.5 months with placebo plus nab-paclitaxel (hazard ratio for progression or death, 0.80; 95% confidence interval [CI], 0.69 to 0.92; P=0.002); among patients with PD-L1-positive tumors, the median progression-free survival was 7.5 months and 5.0 months, respectively (hazard ratio, 0.62; 95% CI, 0.49 to 0.78; P<0.001). In the intention-to-treat analysis, the median overall survival was 21.3 months with atezolizumab plus nab-paclitaxel and 17.6 months with placebo plus nab-paclitaxel (hazard ratio for death, 0.84; 95% CI, 0.69 to 1.02; P=0.08); among patients with PD-L1-positive tumors, the median overall survival was 25.0 months and 15.5 months, respectively (hazard ratio, 0.62; 95% CI, 0.45 to 0.86). No new adverse effects were identified. Adverse events that led to the discontinuation of any agent occurred in 15.9% of the patients who received atezolizumab plus nab-paclitaxel and in 8.2% of those who received placebo plus nab-paclitaxel.

CONCLUSIONS

Atezolizumab plus nab-paclitaxel prolonged progression-free survival among patients with metastatic triple-negative breast cancer in both the intention-to-treat population and the PD-L1-positive subgroup. Adverse events were consistent with the known safety profiles of each agent. (Funded by F. Hoffmann-La Roche/Genentech; IMpassion130 ClinicalTrials.gov number, NCT02425891 .).

Long-term survival follow-up of atezolizumab in combination with platinum-based doublet chemotherapy in patients with advanced non-small-cell lung cancer

BACKGROUND

Before the availability of immunotherapy, chemotherapy was standard first-line therapy for non-small-cell lung cancer (NSCLC) lacking actionable gene alterations. Preclinical evidence suggests chemotherapy is immunomodulatory, supporting chemotherapy/immunotherapy combinations. Atezolizumab, anti-programmed death ligand-1 (PD-L1) antibody, blocks programmed cell death protein-1 and B7.1 interaction with PD-L1. GP28328 (NCT01633970) assessed atezolizumab with chemotherapy in multiple tumours; we report results for advanced, treatment-naïve NSCLC.

METHODS

Patients received atezolizumab plus carboplatin with paclitaxel (Arm C: atezo/cb/pac), pemetrexed (Arm D: atezo/cb/pem, maintenance pemetrexed permitted), or nab-paclitaxel (Arm E: atezo/cb/nab-pac), four-six cycles, then atezolizumab maintenance. Primary end-point was safety; secondary end-points were objective response rate (ORR), progression-free survival (PFS) and overall survival (OS).

RESULTS

Seventy-six NSCLC patients were enrolled (n = 25, 25 and 26 for Arms C, D and E, respectively). Common treatment-related grade III/IV adverse events were neutropenia (36% atezo/cb/pac, 36% atezo/cb/pem, 42% atezo/cb/nab-pac) and anaemia (16% atezo/cb/pac, 16% atezo/cb/pem, 31% atezo/cb/nab-pac). Confirmed ORRs were 36% atezo/cb/pac, 68% atezo/cb/pem (one complete response [CR]) and 46% atezo/cb/nab-pac (four CRs). Median PFS was 7.1 months, (95% confidence interval [CI]: 4.2-8.3), 8.4 months (95% CI: 4.7-11) and 5.7 months (95% CI: 4.4-14.8), respectively. Median OS was 12.9 months (95% CI: 8.8-21.3), 18.9 months (95% CI: 9.9-27.4) and 17.0 months (95% CI: 12.7-not evaluable), respectively.

CONCLUSION

Atezolizumab with chemotherapy was well tolerated with encouraging efficacy, though the analysis was limited by small numbers. NSCLC chemotherapy combination studies are ongoing. CLINICALTRIALS.

GOV IDENTIFIER

NCT01633970.

Abstract CT028: Atezolizumab (atezo) + nab-paclitaxel (nab-pac) in metastatic triple-negative breast cancer (mTNBC): 2-year update from a ph Ib trial

Introduction: Outcomes for patients (pts) with mTNBC remain poor, with chemotherapy as a historic mainstay treatment. Atezo (anti-PD-L1) demonstrated single-agent activity in mTNBC, and initial data suggested the addition of chemotherapy was safe with encouraging activity (Adams, 2016). Here we report long-term outcomes, with OS, for atezo + nab-pac in mTNBC.

Methods: Arm F of multi-cohort Ph Ib study (NCT01633970) enrolled pts with locally advanced unresectable/stage IV mTNBC and 0 to 2 prior regimens for advanced disease. Atezo 800 mg IV q2w and nab-pac 125 mg/m2 IV qw (3 weeks on/1 week off) were given concurrently (with nab-pac run-in for biopsy cohort); maintenance atezo was permitted until loss of clinical benefit. In-tumor PD-L1 expression (VENTANA SP142 assay), CD8 and stromal TILs were assessed by IHC; blood-based CD8+Ki67+ via FACS, and CXCL10 cytokine RNA by NanoString.

Results: Of 33 evaluable pts, 82% had ECOG PS 1, 58% had visceral mets, and median age was 55 years (data cutoff, April 30, 2017). Grade 3-4 treatment-related AEs (TRAE) occurred in 73%, with no Grade 5 TRAEs. Atezo-related AEs ≥ 20% included fatigue, pyrexia and decreased neutrophil count. Five pts discontinued nab-pac due to typical chemotherapy-related toxicities, and 3 withdrew from atezo due to TRAEs. Responses occurred across all subgroups (Table), with numerically higher ORR and longer OS/PFS in pts with less pre-treatment and higher PD-L1 status. Serial biopsy samples (n = 14) had elevated PD-L1+ TILs after combination treatment (but not after nab-pac alone). Peripheral blood analyses found transient on-treatment increases in CD8+Ki67+ and CXCL10, which were independent of efficacy.

Conclusions: In this single-arm study cohort, atezo + nab-pac was well tolerated with promising efficacy, especially for treatment-naive pts. Ongoing randomized Ph III trial IMpassion130 (NCT02425891) is investigating this regimen in untreated mTNBC.

Table. EfficacySubgroup/OutcomeCurrent Line of TherapyPD-L1 IC StatusaAll Ptsb (N = 33)1L (n = 13)2L+c (n = 20)IC1/2/3  (n = 12)IC0 (n = 12)Confirmed ORR (95% CI)54% (25, 81)30% (12, 54)42% (15, 72)33% (10, 65)39% (23, 58)mDOR (range)7.8 mo (2.9-11.5+)10.9 mo (3.7-20.9+)9.1 mo (2.9-16.2)10.2 mo (3.7-20.9+)9.1 mo (2.9-20.9+)mPFS (95% CI)8.6 mo (5.2, 11.5)5.1 mo (3.3, 7.3)6.9 mo (5.2, 11.0)5.1 mo (3.5, 6.8)5.5 mo (5.1, 7.7)mOS (95% CI)24.2 mo (11.5, NE)12.4 mo (7.5, 21.9)21.9 mo (13.1, NE)11.4 mo (7.5, NE)14.7 mo (10.1, NE)IC, tumor-infiltrating immune cells; mDOR, median duration of response; mPFS, median progression-free survival; mOS, median overall survival; mTNBC, metastatic triple-negative breast cancer; NE, not estimable; ORR, objective response rate; PD-L1, programmed death-ligand 1.a Excludes 9 pts with unknown PD-L1 status.b Includes 25 pts enrolled in the serial biopsy cohort and 8 in the safety cohort. Median durations of atezolizumab exposure, safety follow-up and efficacy follow-up were 5.6 mo (range, 0-30), 6.9 mo (range, 1.7-30.3) and 24.4 mo (95% CI: 22.1, 28.8), respectively.cIncludes 1 pt who received 3 prior therapies for mTNBC.Citation Format: Paula R. Pohlmann, Jennifer R. Diamond, Erika Hamilton, Sara M. Tolaney, Wei Zhang, Koho Iizuka, Paul Foster, Luciana Molinero, Roel Funke, Sylvia Adams. Atezolizumab (atezo) + nab-paclitaxel (nab-pac) in metastatic triple-negative breast cancer (mTNBC): 2-year update from a ph Ib trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr CT028.

Stress system dysregulation in pediatric generalized anxiety disorder associated with comorbid depression

Because chronic stress is an important risk factor for anxiety states and depressive disorders, we studied hypothalamus-pituitary-adrenal (HPA) axis and sympathetic system activity via changes in cortisol and alpha amylase activity levels in pediatric generalized anxiety disorder (GAD) patients (n = 26) with comorbid depression and a healthy comparison group (n = 26). Morning plasma cortisol and diurnal profiles of salivary cortisol and salivary alpha amylase (sAA) activity were assessed, also reactivity of HPA-axis, sAA activity, and heart rate following a psychosocial stressor (Trier Social Stress Test for children). GAD patients with comorbid depression showed increased morning plasma and salivary cortisol levels, ameliorating throughout in-patient treatment, and higher sAA activity in their diurnal profile. Both HPA and sympathetic activity positively correlated with the severity of anxiety and depression. We also demonstrated a blunted HPA and sympathetic response to acute stress in patients. This pattern of neuroendocrine and sympathetic changes seems to be distinct from the one previously reported in pediatric patients with only social anxiety or depressive disorders. We propose morning plasma and saliva cortisol levels as potential physiological indicators for supporting the evaluation of symptoms' severity and treatment progress in children with GAD and comorbid depressive disorder.

Atezolizumab (atezo) plus platinum-based chemotherapy (chemo) in non-small cell lung cancer (NSCLC): Update from a phase Ib study

9092

Background: Platinum-based chemo is a standard first-line (1L) therapy for NSCLC lacking actionable gene alterations. Preclinical evidence suggests that chemo can play an immunomodulatory role and induce tumor antigen release, supporting combining chemo with immunotherapy. Atezo is a humanized and Fc-region-modified monoclonal anti-programmed death-ligand-1 (PD-L1) antibody that blocks interaction with PD1 or B7.1. The GP28328 study (NCT01633970) assessed safety and efficacy of atezo plus 1L chemo regimens in multiple tumor types. Methods: In this multicenter, multi-arm study, patients (pts) with locally advanced or metastatic NSCLC with no prior chemo for advanced disease received 15 mg/kg atezo IV q3w with standard doses of chemo (Arm C: carboplatin [carbo]+paclitaxel q3w; Arm D: carbo+pemetrexed q3w; Arm E: carbo+nab-paclitaxel qw) all for ≤6 cycles followed by atezo maintenance until loss of clinical benefit (+ pemetrexed maintenance until progression, Arm D). The primary endpoint was safety; secondary endpoints were overall response rate (ORR), PFS, and OS. Results: By the 30 Aug 2016 cut-off, 76 NSCLC pts were evaluable (n = 25, 25, 26 for Arms C, D, E, respectively). At this cut-off, the most common treatment-related grade 3–4 adverse events (AEs) were neutropenia (36% C, 36% D, 42% E) and anemia (16% C, 16% D, 31% E). Three potentially related grade 5 AEs were seen (arm C: pneumonia; arm D: systemic candida; arm E: autoimmune hepatitis). Confirmed ORRs were 36%, 64%, 46% for Arms C, D (1 CR), and E (4 CR). Median PFS (95% CI) was 7.1 months (4.2–8.3) for C, 8.4 months (4.7–11) for D, and 5.7 months (4.4–14.8) for E. Median OS (95% CI) was 12.9 months (8.8–not evaluable) for C, 19.3 months (14.7–27.4) for D, and 14.8 months (12.7–not evaluable) for E. Conclusions: Atezo was well tolerated when combined with various chemo regimens for advanced NSCLC. Clinical activity in terms of ORR was favorable supporting potential synergy between atezo and chemo. PFS and OS data show promising benefits, but are limited by small numbers and wide confidence intervals. Phase III studies that include chemotherapy and atezolizumab are currently ongoing. Clinical trial information: NCT01633970.

Randomized Phase II Trial of Parsatuzumab (Anti-EGFL7) or Placebo in Combination with FOLFOX and Bevacizumab for First-Line Metastatic Colorectal Cancer

Lessons Learned.

These negative phase II results for parsatuzumab highlight the challenges of developing an agent intended to enhance the efficacy of vascular endothelial growth factor inhibition without the benefit of validated pharmacodynamic biomarkers or strong predictive biomarker hypotheses.

Any further clinical development of anti‐EGFL7 is likely to require new mechanistic insights and biomarker development for antiangiogenic agents.

Background.

EGFL7 (epidermal growth factor‐like domain 7) is a tumor‐enriched vascular extracellular matrix protein that supports endothelial cell survival. This phase II trial evaluated the efficacy of parsatuzumab (also known as MEGF0444A), a humanized anti‐EGFL7 IgG₁ monoclonal antibody, in combination with modified FOLFOX6 (mFOLFOX6) (folinic acid, 5‐fluorouracil, and oxaliplatin) bevacizumab in patients with previously untreated metastatic colorectal cancer (mCRC).

Methods.

One‐hundred twenty‐seven patients were randomly assigned to parsatuzumab, 400 mg, or placebo, in combination with mFOLFOX6 plus bevacizumab, 5 mg/kg. Treatment cycles were repeated every 2 weeks until disease progression or unacceptable toxicity for a maximum of 24 months, with the exception of oxaliplatin, which was administered for up to 8 cycles.

Results.

The progression‐free survival (PFS) hazard ratio was 1.17 (95% confidence interval [CI], 0.71–1.93; p = .548). The median PFS was 12 months for the experimental arm versus 11.9 months for the control arm. The hazard ratio for overall survival was 0.97 (95% CI, 0.46–2.1; p = .943). The overall response rate was 59% in the parsatuzumab arm and 64% in the placebo arm. The adverse event profile was similar in both arms.

Conclusions.

There was no evidence of efficacy for the addition of parsatuzumab to the combination of bevacizumab and chemotherapy for first‐line mCRC.

Atezolizumab in combination with bevacizumab enhances antigen-specific T-cell migration in metastatic renal cell carcinoma

Anti-tumour immune activation by checkpoint inhibitors leads to durable responses in a variety of cancers, but combination approaches are required to extend this benefit beyond a subset of patients. In preclinical models tumour-derived VEGF limits immune cell activity while anti-VEGF augments intra-tumoral T-cell infiltration, potentially through vascular normalization and endothelial cell activation. This study investigates how VEGF blockade with bevacizumab could potentiate PD-L1 checkpoint inhibition with atezolizumab in mRCC. Tissue collections are before treatment, after bevacizumab and after the addition of atezolizumab. We discover that intra-tumoral CD8⁺ T cells increase following combination treatment. A related increase is found in intra-tumoral MHC-I, Th1 and T-effector markers, and chemokines, most notably CX3CL1 (fractalkine). We also discover that the fractalkine receptor increases on peripheral CD8⁺ T cells with treatment. Furthermore, trafficking lymphocyte increases are observed in tumors following bevacizumab and combination treatment. These data suggest that the anti-VEGF and anti-PD-L1 combination improves antigen-specific T-cell migration.

Cancer immunotherapy can be used in combination with other therapies for a better response. Here, the authors conduct a phase Ib clinical study and report the clinical activity and the immune response of the anti-PDL1 agent, atezolizumab, in combination with bevacizumab in ten patients with metastatic renal cell carcinoma.

Abstract A017: PD-L1 as a predictive biomarker for atezolizumab (MPDL3280A; anti-PDL1) in non-small cell lung cancer (NSCLC)

Background: Programmed death ligand-1 (PD-L1), a ligand for PD-1 and B7.1, is broadly expressed on tumor cells (TC) and tumor-infiltrating immune cells (IC) in many human cancers. PD-L1 expression on either TC or IC can negatively regulate antitumor T-cell function within the tumor microenvironment (TME). Consistent with this, the ORR, PFS and OS benefit of atezolizumab (atezo) across PhI and PhII studies appeared to correlate with increasing baseline PD-L1 expression levels on TC and/or IC. Therefore, we explored the biologic reasons for PD-L1 expression on TC and IC, the association with response to atezo and the intrapatient heterogeneity of PD-L1 expression in NSCLC.

Methods: Tumor specimens were obtained from patients (pts) prescreened and/or enrolled in NSCLC atezo trials (PhI PCD4989g, PhII POPLAR and FIR [n=1360]) and from pts treated at MSKCC (n=39). Samples included 14 synchronous and 106 metachronous pairs collected in FIR or at MSKCC. Using the SP142 IHC assay, which has been optimized to detect PD-L1 on both TC and IC, PD-L1 expression was scored at 4 levels (TC0-3 and IC0-3) based on increasing expression. A subset of samples was further characterized by histopathologic review and gene expression by RNAseq. CD8 expression (clone C8/144B) was assessed in the tumor center, invasive margin and periphery by IHC.

Results: PD-L1 was expressed on IC only, on TC only or on both TC and IC within the TME. Tumors with the highest (TC3 or IC3), moderate/high (TC2/3 or IC2/3) and any (TC1/2/3 or IC1/2/3) PD-L1 expression represented ≈15%, ≈38% and ≈70% of NSCLC, respectively. PD-L1 expression was similar across all paired synchronous and metachronous tissues. At the TC3 or IC3 cutoff, PD-L1 status remained unchanged in 86% of paired synchronous specimens and in 78% of metachronous pairs. Analysis of PD-L1 expression patterns revealed the existence of exclusive TC and IC subpopulations at each PD-L1 expression level, unique to NSCLC and not seen in other cancers, e.g. UBC. Strikingly, TC3 and IC3 tumors represented 2 distinct populations, with &lt;1% overlap, each benefiting from atezo. In POPLAR, ORR in TC3 and IC3 subgroups was 40% and 30%, respectively, vs 14.6% in all pts treated with atezo. IC3 tumors had a high frequency of immune infiltrates, including CD8+ T cells, localized in the intra-epithelium, epithelial/stroma interface and stroma. These tumors also exhibited high expression of genes associated with effector T cells, consistent with PD-L1 regulated by an adaptive IFNγ-driven mechanism. However, high infiltration of CD8+ T cells within the tumor at baseline was not associated with response to atezo (P=.39), suggesting that the mechanism of response is not exclusively due to adaptive antitumor T-cell immunity. In contrast, TC3 tumors had distinct histopathologic characteristics, with a dense desmoplastic and sclerotic TME and low intratumoral CD8 infiltrate. PD-L1 on TC appeared to be regulated by intrinsic tumor mechanisms, including promoter methylation. TC0 and IC0 tumors (lowest/no PD-L1 expression; ≈30% of NSCLC) showed little/no evidence of immune infiltration or activation, consistent with immunologic ignorance.

Conclusions: These data demonstrated that NSCLC has unique PD-L1 expression patterns. High expression of PD-L1 on TC and/or IC in NSCLC confers sensitivity to atezo, despite exhibiting distinct immunologic profiles. These results further our understanding of how atezo promotes responses in tumors expressing PD-L1 on TC and/or IC and emphasizes the need to assess PD-L1 on both TC and IC in NSCLC. In addition, intrapatient heterogeneity in PD-L1 expression was relatively low in both synchronous and metachronous tissues, indicating that various types of tumor samples (e.g. primary or metastatic, fresh or archival) can be reliably used to assess PD-L1 expression with the SP142 assay.

Citation Format: Marcin Kowanetz, Hartmut Koeppen, Wei Zou, Sanjeev Mariathasan, Matthew Hellmann, Mark Kockx, Colombe Chappey, Edward Kadel, Dustin Smith, Natasha Miley, Vincent Leveque, Roel Funke, Alan Sandler, Ian McCaffery, Lukas Amler, Daniel Chen, Priti Hegde. PD-L1 as a predictive biomarker for atezolizumab (MPDL3280A; anti-PDL1) in non-small cell lung cancer (NSCLC). [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A017.

EXEL-7647 inhibits mutant forms of ErbB2 associated with lapatinib resistance and neoplastic transformation

PURPOSE

Mutations associated with resistance to kinase inhibition are an important mechanism of intrinsic or acquired loss of clinical efficacy for kinase-targeted therapeutics. We report the prospective discovery of ErbB2 mutations that confer resistance to the small-molecule inhibitor lapatinib.

EXPERIMENTAL DESIGN

We did in vitro screening using a randomly mutagenized ErbB2 expression library in Ba/F3 cells, which were dependent on ErbB2 activity for survival and growth.

RESULTS

Lapatinib resistance screens identified mutations at 16 different ErbB2 amino acid residues, with 12 mutated amino acids mapping to the kinase domain. Mutations conferring the greatest lapatinib resistance cluster in the NH2-terminal kinase lobe and hinge region. Structural computer modeling studies suggest that lapatinib resistance is caused by multiple mechanisms; including direct steric interference and restriction of conformational flexibility (the inactive state required for lapatinib binding is energetically unfavorable). ErbB2 T798I imparts the strongest lapatinib resistance effect and is analogous to the epidermal growth factor receptor T790M, ABL T315I, and cKIT T670I gatekeeper mutations that are associated with clinical drug resistance. ErbB2 mutants associated with lapatinib resistance transformed NIH-3T3 cells, including L755S and T733I mutations known to occur in human breast and gastric carcinomas, supporting a direct mechanism for lapatinib resistance in ErbB2-driven human cancers. The epidermal growth factor receptor/ErbB2/vascular endothelial growth factor receptor inhibitor EXEL-7647 was found to inhibit almost all lapatinib resistance-associated mutations. Furthermore, no ErbB2 mutations were found to be associated with EXEL-7647 resistance and lapatinib sensitivity.

CONCLUSIONS

Taken together, these data suggest potential target-based mechanisms of resistance to lapatinib and suggest that EXEL-7647 may be able to circumvent these effects.

Initial sequencing and analysis of the human genome

The human genome holds an extraordinary trove of information about human development, physiology, medicine and evolution. Here we report the results of an international collaboration to produce and make freely available a draft sequence of the human genome. We also present an initial analysis of the data, describing some of the insights that can be gleaned from the sequence.

[Analysis of gait using motography in healthy children and patients with neurologic disorders. II: Quantitative analysis]

Light pattern recording of movements by Motografie results in data representing changes in space and time; single pictures of these curves can be analysed in detail. The method was used for gait analysis in two healthy children, in a boy with minimal cerebral dysfunction and hyperactivity, and in two patients with spastic diplegia. From describing all phases of gait cycles different variables were chosen to assess movement patterns quantitatively; thus, curves could be described by various parameters. Differences were seen between normal, mildly impaired and severely handicapped children. Results obtained are in good agreement with a qualitative analysis of pictures and with data from the literature using different methods.

[Analysis of gait using motography in healthy children and patients with neurologic disorders. I: Qualitative analysis]

Light pattern recording of movements is applicable to assess changes in space and time as well by using single photographic pictures. The method called Motografie has the advantage to work with a special light source; therefore, it is useful in clinical practice and research. Data can be analysed by describing pictures (qualitative analysis) as well as by quantitative measurements from the light pattern curves. By using Motografie gait pictures were studied in two healthy children, in a boy with minimal cerebral dysfunction and hyperactivity, and in two patients suffering from spastic diplegia. Movement curves from different parts of the body (shoulders, hands, hips, knees, feet) could be described in regard to their pattern and quality. In comparing healthy, mildly impaired and severely handicapped children specific features were noted to characterize different gait patterns. This is useful in clinical diagnosis and practicable to assess developmental changes as well as results of therapeutic measures in movement disorders.