Response to Brentuximab Vedotin by CD30 Expression in Non-Hodgkin Lymphoma

Background

The safety and efficacy of brentuximab vedotin (BV), an antibody-drug conjugate directed to the CD30 antigen, has been assessed in several trials in patients with peripheral T-cell lymphoma (PTCL), cutaneous T-cell lymphoma (CTCL), or B-cell non-Hodgkin lymphoma (NHL). The objective of this research was to examine the relationship between CD30 expression level and clinical response to BV.

Patients and Methods

We analyzed response in patients treated with BV monotherapy in 5 prospective clinical studies in relapsed or refractory PTCL, CTCL, or B-cell NHL. CD30 expression was assessed by immunohistochemistry (IHC) using the Ber H2 antibody for 275 patients.

Results

Across all 5 studies, 140 (50.9%) patients had tumors with CD30 expression <10%, including 60 (21.8%) with undetectable CD30 by IHC. No significant differences were observed for any study in overall response rates between patients with CD30 expression ≥10% or <10%. Median duration of response was also similar in the CD30 ≥10% and <10% groups for all studies.

Conclusions

In this analysis of studies across a range of CD30-expressing lymphomas, CD30 expression alone, as measured by standard IHC, does not predict clinical benefit from BV, making the determination of a threshold level of expression uncertain.

Response to brentuximab vedotin versus physician's choice by CD30 expression and large cell transformation status in patients with mycosis fungoides: An ALCANZA sub-analysis

INTRODUCTION

Mycosis fungoides (MF), the most common type of cutaneous T-cell lymphoma, can lead to disfiguring lesions, debilitating pruritus and frequent skin infections. This study assessed response to brentuximab vedotin in patients with MF in the phase III ALCANZA study.

METHODS

Baseline CD30 levels and large-cell transformation (LCT) status were centrally reviewed in patients with previously-treated CD30-positive MF using ≥2 skin biopsies obtained at screening; eligible patients required ≥1 biopsy with ≥10% CD30 expression. Patients were categorised as CD30_min < 10% (≥1 biopsy with <10% CD30 expression), or CD30_min ≥ 10% (all biopsies with ≥10% CD30 expression) and baseline LCT present or absent. Efficacy analyses were the proportion of patients with objective response lasting ≥4 months (ORR4) and progression-free survival (PFS).

RESULTS

Clinical activity with brentuximab vedotin was observed across all CD30 expression levels in patients with ≥1 biopsy showing ≥10% CD30 expression. Superior ORR4 was observed with brentuximab vedotin versus physician's choice in patients: with CD30_min < 10% (40.9% versus 9.5%), with CD30_min ≥ 10% (57.1% versus 10.3%), with LCT (64.7% versus 17.6%) and without LCT (38.7% versus 6.5%). Brentuximab vedotin improved median PFS versus physician's choice in patients: with CD30_min < 10% (16.7 versus 2.3 months), with CD30_min ≥ 10% (15.5 versus 3.9 months), with LCT (15.5 versus 2.8 months) and without LCT (16.1 versus 3.5 months). Safety profiles were generally comparable across subgroups.

CONCLUSION

These exploratory analyses demonstrated that brentuximab vedotin improved rates of ORR4 and PFS versus physician's choice in patients with CD30-positive MF and ≥1 biopsy showing ≥10% CD30 expression, regardless of LCT status.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov, NCT01578499.

Response to A+CHP by CD30 expression in the ECHELON-2 trial

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Background: Brentuximab vedotin (BV) is an antibody-drug conjugate that targets CD30. The ECHELON-2 (E-2) study demonstrated significantly longer progression-free and overall survival with BV plus cyclophosphamide, doxorubicin, and prednisone (A+CHP) versus CHOP in frontline treatment of patients (pts) with CD30+ peripheral T-cell lymphoma (PTCL). Complete remission (CR) rate (A+CHP 68%; CHOP 56%) and objective response rate (ORR) (A+CHP 83%; CHOP 72%) were also significantly increased. Expression of CD30 is universal in systemic anaplastic large-cell lymphoma (sALCL) but variable among non-sALCL subtypes. As ORR is a direct measure of antitumor activity, we examined response to A+CHP by CD30 expression. Methods: Pts with CD30+ (≥10% by local review) PTCL were included in E-2. Eligible histologies included ALK+ sALCL (IPI ≥2), ALK− sALCL, PTCL-not otherwise specified (PTCL-NOS), angioimmunoblastic T-cell lymphoma (AITL), adult T-cell leukemia/lymphoma, enteropathy-associated T-cell lymphoma, and hepatosplenic T-cell lymphoma. We analyzed the relationship between CD30 expression (IHC Ber H2 antibody) above and below the median (median CD30=18% PTCL-NOS; 25% AITL) and CR rate, ORR, and duration of CR (DOCR) in pts with AITL and PTCL-NOS treated with A+CHP. Results: Most (26/29, 90%) AITL pts had CD30 expression between 10% and 30%. PTCL-NOS pts were more evenly distributed across levels of CD30 expression ranging from 10% to 100%. CD30 levels were neither predictive of response (Table) nor significantly associated with DOCR in pts with AITL (P=0.30) or PTCL-NOS (P=0.90) (log-rank test). Response by CD30 expression. Clinical trial information: NCT01777152. Conclusions: CD30 expression above vs below median (or at 10%) did not predict response to A+CHP in E-2 non-ALCL subtypes, as responses were seen across CD30 levels. This may be due to intra- and inter-tumoral heterogeneity of CD30 expression, limitations of IHC, the nature of CD30 on the cell surface, and multiple mechanisms of action of BV. Further evaluation of the expression-response relationship in PTCL pts with CD30 <10% is warranted.[Table: see text]

Response to brentuximab vedotin by CD30 expression: Results from five trials in PTCL, CTCL, and B-cell lymphomas

7543

Background: Brentuximab vedotin (BV), an antibody-drug conjugate targeting CD30, has been evaluated in multiple trials in patients (pts) with peripheral T-cell lymphoma (PTCL), cutaneous T-cell lymphoma (CTCL), or B-cell lymphoma. We examined the ability of CD30 expression level to predict response to BV across these patient populations. Methods: Data were integrated from 275 pts with PTCL, CTCL, and B-cell lymphoma treated with BV from 5 prospective clinical trials. Study SGN35-012 evaluated BV plus rituximab or BV monotherapy in pts with relapsed/refractory non-Hodgkin lymphoma. The ALCANZA study compared BV to physician’s choice of methotrexate or bexarotene in pts with mycosis fungoides (MF) or primary cutaneous anaplastic large cell lymphoma (pcALCL). Three investigator-sponsored trials evaluated BV monotherapy in pts with relapsed PTCL, MF, and pcALCL (35-IST-030, 35-IST-001, 35-IST-002). Exploratory analyses were conducted to examine the relationship between CD30 expression and objective response rate (ORR) for pts with CD30 expression ≥10%, <10%, or undetectable (0%) by IHC (malignant cells or lymphoid infiltrate; local review). Results: 143 pts had tumors with CD30 <10%, including 58/143 with undetectable CD30. Activity with BV was observed at all levels of CD30 expression, including CD30=0 (Table). Analysis of the interaction between CD30 and duration of response is ongoing and will be presented in the final poster. ORR by CD30 expression, n/N (%). Clinical trial information: NCT01421667, NCT02588651, NCT01578499, NCT01352520, NCT01396070. Conclusions: CD30 expression levels ≥10%, <10%, or undetectable did not predict response to BV in a range of CD30-expressing lymphomas: Clinical responses occurred in pts with CD30 low and CD30 undetectable lymphomas. Limitations of IHC, the dynamic nature and heterogeneity of cell-surface CD30 expression, and multiple mechanisms of action of BV may all contribute to this observation.[Table: see text]

Abstract A10: In silico design of biomarker-optimized drug combinations in ERBB2+ cancers

Crosstalk and compensatory circuits within cancer signaling networks fundamentally limit the activity of targeted therapies. Combination drug regimens are thus required to fully inhibit an oncogenic network. However, rationally designing optimal combinations, given the large number of targeted agents available remains a challenge. Previously, we developed a multi-scale systems model of ERBB2-high breast cancer to quantitatively interrogate relationships between biomarkers (proxies for the mode of network activation) and combination drug efficacy. We found that targeting the ERBB2-ERBB3 heterodimer with a combination of ERBB2 inhibitors (trastuzumab and lapatinib) and an ERBB3 inhibitor (MM-111) was more effective at inducing tumor regression than the combination of an AKT and MEK inhibitor (MK2206 and GSK1120212), and was significantly better tolerated. However, the model was parameterized based on data collected from one cell line. Here we have performed profiling of an 18-cell line panel to assess whether our model and results are extendable to other ERBB2-high cancers. We monitored cell viability and signaling events upon AKT and MEK inhibitor treatments in the presence or absence of the ERBB3 ligand heregulin in these cell lines. While all cells were ERBB2+, we observed widely variable phenotypic and signaling dependencies on the PI3K/AKT and MAPK/ERK pathway activities across the panel. At the phenotypic level, cells primarily depend on either AKT or ERK signaling in basal conditions. Interestingly, upon heregulin stimulation some cells lines switch pathway dependency from AKT to ERK. Adaptive feedback circuits downstream of ERK and AKT were identified in all cell lines, though the identity and strength vary extensively. ERBB3 signaling and total AKT were consistently up-regulated to various degrees upon AKT inhibitor treatment. In contrast, multiple ERBB receptors as well as other RTKS, AKT signaling, and total ERK were upregulated in the response to MEK inhibition. While it is plausible that signaling pathways beyond AKT and ERK are modulating cell viability, we are able to quantitatively describe cell growth regulation based on AKT and ERK pathway activity using quantitative logic-based modeling framework. Our results will help us better understand how signaling events are decoded by cancer cells into phenotypic responses, and enable in silico drug combination screening across molecularly and functionally heterogeneous cancers.

Citation Format: Jinyan Du, Daniel Kirouac, Johanna Lahdenranta, Ryan Overland, Matthew Onsum, Charlotte McDonagh. In silico design of biomarker-optimized drug combinations in ERBB2+ cancers. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr A10.

Preclinical activity of MM-111, a bispecific ErbB2/ErbB3 antibody in previously treated ErbB2-positive gastric and gastroesophageal junction cancer

48

Background: ErbB2 (HER2) overexpression has been reported in 7-34% of gastric cancers. ErbB3 (HER3) is the preferred dimerization partner of ErbB2, and ErbB2/ErbB3 heterodimer activation is implicated in the progression and metastasis of ErbB2+ tumors. Activation of ErbB3 signaling is a postulated resistance mechanism to current ErbB2-directed therapies and select chemotherapies. In line with this research, ErbB3 levels are associated with poor prognosis in gastric cancers. MM-111 is a bi-specific antibody that docks to ErbB2 and inhibits ErbB3 signaling in cells that overexpress ErbB2. In this study, MM-111 was evaluated in ErbB2+ gastric cancer by testing the activity of MM-111 in ErbB2+ pre-clinical models of gastric cancer, and by assessing the prevalence of potentially predictive biomarkers in a panel of archived gastric and gastroesophageal junction (GEJ) tumors. Methods: MM-111 was tested in ErbB2+ gastric cancer xenografts that were either untreated or after tumors ceased to respond to trastuzumab/5-FU. Xenografts were analyzed at multiple time points for the expression of ErbB-receptor family members and their downstream signaling by Luminex -assays. Preclinical data indicate that ErbB2, ErbB3, and heregulin are predictive biomarkers for MM-111. In order to determine the prevalence of our potentially predictive biomarkers in gastric and GEJ cancers, we obtained commercially archived tumor tissue and assayed the tissue for ErbB2 and ErbB3 expression levels using quantitative IHC, and measured heregulin transcript levels by RT-PCR. Results: MM-111 synergizes with various treatment regimens in the 2nd line treatment setting in ErbB2+ gastric cancer xenografts. In our models, the combination of MM-111, trastuzumab, and paclitaxel is particularly effective after tumors progressed on trastuzumab/5-FU. MM-111 inhibits the activity of the ErbB –signaling axis in these models. In addition, 23% of GEJ tumor samples and 20% of gastric samples were positive for potentially predictive biomarkers. Conclusions: ErbB2+xenograft tumors that stop responding to trastuzumab-based therapies benefit from MM-111–based regimens.

Abstract 1888: MM-111, a bispecific HER2 and HER3 antibody, inhibits trastuzumab-resistant tumor cell growth

Amplification of human epidermal growth factor receptor 2 (HER2) occurs in approximately 25% of breast cancers and is associated with increased disease recurrence and poor prognosis. Trastuzumab, a monoclonal antibody targeting HER2, has demonstrated clinical benefit in HER2 over-expressing tumors. However, acquired resistance and disease progression is widely observed in patients treated with trastuzumab. In this experiment our objectives were to dissect the dynamic, molecular mechanisms involved in acquired resistance to trastuzumab and to determine whether MM-111, a novel bispecific antibody fusion protein that specifically targets the HER2/HER3 heterodimer and blocks heregulin binding to HER3, has activity in trastuzumab-resistant tumor cells. BT474 cells were cultured in the presence of trastuzumab and cells were periodically tested for response to trastuzumab and MM-111. Samples were also collected for protein and RNA analyses. Resistance to trastuzumab gradually increased in BT474 cells after four months of exposure to trastuzumab, as measured by a cell proliferation assay. Quantitative flow cytometry analysis showed EGFR, HER2, and HER3 levels on the cell surface of resistant cells were similar to the parental cells. Phospho-protein kinase antibody arrays revealed that signaling pathways associated with the ERK cascade were activated during the development of drug resistance. Western blotting further confirmed that phosphorylation of EGFR, ERK, CREB, c-Jun, and AFT-1 was increased in the resistant cells. Real-time polymerase chain reaction also showed transcript levels of HER ligands, including HRG1α, HRG1α, betacellulin, amphiregulin, epigen, TGFβ, and HB-EGF, dramatically increased in tumor cells that acquired resistance to trastuzumab. Compared to the BT474 parental cells, MM-111 showed a greater inhibition in trastuzumab-resistant cells in a spheroid growth assay. Furthermore, trastuzumab-resistant cells became more sensitive to gefitinib and erlotinib, both EGFR inhibitors. The combination of gefitinib or erlotinib with MM-111 showed greater inhibition than either drug alone. In conclusion, our data suggest that one mechanism by which HER2 overexpressing breast cancer cells develop resistance to trastuzumab is to up-regulate ligand-dependent EGFR and HER3 signaling pathways. The use of MM-111 and EGFR inhibitors may provide an effective therapeutic strategy for the treatment of trastuzumab-resistant cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1888. doi:1538-7445.AM2012-1888

Abstract C27: Targeting ErbB3 and EGFR in lung cancer patients: A phase I trial of MM-121 in combination with erlotinib in patients with non-small cell lung cancer (NSCLC)

Background: The benefit of EGFR tyrosine kinase inhibitors (TKIs) is largely restricted to EGFR mutation-positive cancers and resistance invariably develops. A central theme of acquired resistance is persistent ErbB3 signaling, resulting in activation of the PI3K/AKT survival pathway. MM-121 is a fully human IgG1 monoclonal antibody (mAb) to ErbB3 with pre-clinical activity as a single agent and in combination with erlotinib in NSCLC, particularly in cancers with ligand-dependent activation of EGFR. This phase 1 study evaluated the safety and tolerability of MM-121 and erlotinib in NSCLC, as well as PK, immunogenicity, efficacy endpoints and exploratory biomarker evaluation.

Methods: Patients with advanced NSCLC, good performance status and adequate organ function were enrolled. Patients were EGFR TKI-naïve, unless they were EGFR mutant, in which case acquired resistance was allowed. MM-121 was administered weekly and erlotinib was administered daily. Seven cohorts were enrolled, evaluating varying dose levels of the combination, as well as alternate MM-121 infusion schedules. Dose levels were determined by safety and pharmacokinetic (PK) data.

Results: Between February 2010 and July 2011, 33 patients were enrolled. Median age was 64 years and there were 19 (57.5%) women. Twenty-four patients were erlotinib-naïve and 1 patient was an EGFR mutant. The most frequent adverse events were rash, diarrhea, nausea and fatigue. As of 31 July 2001, 16 patients remain on study. Full results will be presented at the meeting.

Conclusions: In this phase 1 dose escalation study, MM-121 plus erlotinib was well tolerated by the majority of patients. A phase 2 study is planned.

Reference: NCT00994123

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr C27.

Abstract 3756: Prediction of xenograft response to MM-121, an anti-ErbB3 inhibitor, using computational modeling and measurements of five biomarkers

One of the challenges faced by targeted therapeutics currently in the clinic is the relatively small population of patients who derive significant benefit from their use. We report the development of a preclinical classifier which can correctly predict xenograft response to MM-121, an anti-ErbB3 antibody, based on the measurement of a few key biomarkers in cell lysates.

Deregulation of the ErbB family receptors is common in many cancers. Using a combination of computational modeling and quantitative experiments we identified ErbB3 as a key mediator of mitogenic signaling downstream of the ErbB receptors. Based on these results, we developed MM-121, a first in class anti-ErbB3 monoclonal antibody that blocks heregulin-induced signaling and inhibits tumor growth in multiple xenograft models of human cancer.

Here we present our efforts to derive a predictive biomarker signature that identifies tumors that are responsive to MM-121. Using our computational model of the ErbB signaling pathway we identified the five most critical proteins for predicting activation of phospho-AKT - a key mediator of cell survival and apoptosis. These proteins include MM-121's target, ErbB3, and its ligand, heregulin. We profiled these biomarkers in a large panel of cancer cell lines, and using the measured effect of MM-121 on inhibiting tumor growth in eight xenograft tumor models, we determined a classification rule for predicting xenograft response. We subsequently used this classification rule to correctly predict a priori MM-121 response in 11 xenograft models.

These results suggest that our computationally-derived biomarker signature is sufficient for predicting response to MM-121 in xenografts, and could offer significant clinical benefit by helping select patients for MM-121 treatment.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3756.

An ErbB3 antibody, MM-121, is active in cancers with ligand-dependent activation

ErbB3 is a critical activator of phosphoinositide 3-kinase (PI3K) signaling in epidermal growth factor receptor (EGFR; ErbB1), ErbB2 [human epidermal growth factor receptor 2 (HER2)], and [hepatocyte growth factor receptor (MET)] addicted cancers, and reactivation of ErbB3 is a prominent method for cancers to become resistant to ErbB inhibitors. In this study, we evaluated the in vivo efficacy of a therapeutic anti-ErbB3 antibody, MM-121. We found that MM-121 effectively blocked ligand-dependent activation of ErbB3 induced by either EGFR, HER2, or MET. Assessment of several cancer cell lines revealed that MM-121 reduced basal ErbB3 phosphorylation most effectively in cancers possessing ligand-dependent activation of ErbB3. In those cancers, MM-121 treatment led to decreased ErbB3 phosphorylation and, in some instances, decreased ErbB3 expression. The efficacy of single-agent MM-121 was also examined in xenograft models. A machine learning algorithm found that MM-121 was most effective against xenografts with evidence of ligand-dependent activation of ErbB3. We subsequently investigated whether MM-121 treatment could abrogate resistance to anti-EGFR therapies by preventing reactivation of ErbB3. We observed that an EGFR mutant lung cancer cell line (HCC827), made resistant to gefitinib by exogenous heregulin, was resensitized by MM-121. In addition, we found that a de novo lung cancer mouse model induced by EGFR T790M-L858R rapidly became resistant to cetuximab. Resistance was associated with an increase in heregulin expression and ErbB3 activation. However, concomitant cetuximab treatment with MM-121 blocked reactivation of ErbB3 and resulted in a sustained and durable response. Thus, these results suggest that targeting ErbB3 with MM-121 can be an effective therapeutic strategy for cancers with ligand-dependent activation of ErbB3.

A mathematical model for neutrophil gradient sensing and polarization

Directed cell migration in response to chemical cues, also known as chemotaxis, is an important physiological process involved in wound healing, foraging, and the immune response. Cell migration requires the simultaneous formation of actin polymers at the leading edge and actomyosin complexes at the sides and back of the cell. An unresolved question in eukaryotic chemotaxis is how the same chemoattractant signal determines both the cell's front and back. Recent experimental studies have begun to reveal the biochemical mechanisms necessary for this polarized cellular response. We propose a mathematical model of neutrophil gradient sensing and polarization based on experimentally characterized biochemical mechanisms. The model demonstrates that the known dynamics for Rho GTPase and phosphatidylinositol-3-kinase (PI3K) activation are sufficient for both gradient sensing and polarization. In particular, the model demonstrates that these mechanisms can correctly localize the “front” and “rear” pathways in response to both uniform concentrations and gradients of chemical attractants, including in actin-inhibited cells. Furthermore, the model predictions are robust to the values of many parameters. A key result of the model is the proposed coincidence circuit involving PI3K and Ras that obviates the need for the “global inhibitors” proposed, though never experimentally verified, in many previous mathematical models of eukaryotic chemotaxis. Finally, experiments are proposed to (in)validate this model and further our understanding of neutrophil chemotaxis.

Neutrophils target sites of infection and inflammation by sensing chemical signals produced by damaged tissue and infecting microbes and then move in the direction where their concentration is greatest. An open question is how neutrophils integrate this information to determine the direction of motility. We present a mathematical model for the intracellular signaling network regulating polarization and chemotaxis in neutrophils. We demonstrate how the activation of two antagonizing pathways robustly establishes the front and back of the migrating cell. The model is able to reproduce a number of experimental studies, and new experiments are proposed to test different aspects of the model. A key result is the characterization of a coincidence circuit involving phosphatidylinositol-3-kinase (PI3K) and Ras. We demonstrate that this circuit plays a critical role in selectively localizing F-actin to the front of the cell and actomyosin complexes to the rear. As directed motility in response to chemical cues is critical in a number of processes including wound healing and tumor metastasis, the results and insights gained from the model may be applicable to other cell types and organisms.

Numerical computation of diffusion on a surface

We present a numerical method for computing diffusive transport on a surface derived from image data. Our underlying discretization method uses a Cartesian grid embedded boundary method for computing the volume transport in a region consisting of all points a small distance from the surface. We obtain a representation of this region from image data by using a front propagation computation based on level set methods for solving the Hamilton-Jacobi and eikonal equations. We demonstrate that the method is second-order accurate in space and time and is capable of computing solutions on complex surface geometries obtained from image data of cells.