GI oncology molecular tumor board: Fostering collaboration and clinical education for personalized therapy

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Background: In recent years, genomic profiling has become standard of care for several gastrointestinal (GI) cancers. In addition to standard of care indications, comprehensive genomic profiling has led to novel and expanded applications of targeted therapy, chemotherapy, and immunotherapy and facilitated identification of potential clinical trials. A GI molecular tumor board (MTB) was developed with a goal of improving understanding of the biological effects of genomic alterations and their therapeutic implications to enhance personalized therapy. Methods: Foundation Medicine (FM) collaborated with physicians in the GI oncology group of an academic medical center to develop a GI MTB starting March 2019. As of December 2019, 27 GI oncology cases were presented where FoundationOneCDx testing was performed and a clinical question was posed. Cases were discussed by faculty, fellows, research staff, and a clinical genomic scientist and oncologist from FM. Impacted signaling pathways and biomarkers were discussed for each case alongside clinical content so that physicians could consider therapeutic options and clinical trials. Presenting faculty were asked to complete a questionnaire for each case presented to assess the impact of the MTB discussion on clinician knowledge and patient-level treatment recommendations. Results: Of 27 questionnaires sent to 7 providers, 17 (63%) were completed. Respondents indicated that as a result of the MTB, the treatment plan was changed in 2 cases (12%), reinforced in 9 cases (53%) and in 6 cases (35%) there was no effect. On a Likert scale of 1-4 where 1 is “rare/poorly” and 4 is “great” mean scores were as follows: Did this MTB help you understand the biological effects of the main genomic alteration(s) reported in the case presented? 3.3. Did this MTB help you understand the possible therapeutic implications of the main genomic alterations in the case presented? 3.3. Did this MTB improve your understanding of the role of next generation sequencing and comprehensive genomic profiling in making treatment decisions? 3.4. Conclusions: The results of our questionnaire indicate that treatment decisions were changed in a minority of cases based on the MTB. In most cases, clinical decision making was reinforced and understanding of the biological effects of genomic alterations and their therapeutic implications were improved. Based on this feedback we will continue to refine and integrate the GI MTB into clinical care for patients with GI malignancies, and share our experience locally with other disease groups.

OMTX705, a Novel FAP-Targeting ADC Demonstrates Activity in Chemotherapy and Pembrolizumab-Resistant Solid Tumor Models

PURPOSE

The tumor microenvironment plays a key role in cancer development and progression and is involved in resistance to chemo- and immunotherapy. Cancer-associated fibroblast expressing fibroblast-activating protein α (FAPα) is one of the predominant stroma cell types and is involved in resistance to immunotherapy.

EXPERIMENTAL DESIGN

We generated OMTX705, a novel antibody-drug conjugate from a humanized anti-FAP antibody linked to a new cytolysin. Here, we studied its antineoplastic activity in vitro and in preclinical mouse models alone and in combination with chemotherapy as well as immunotherapy in PD-1-resistant tumors.

RESULTS

In Avatar models, OMTX705 showed a 100% tumor growth inhibition and prolonged tumor regressions as single agent and in combination with chemotherapy. Treatment rechallenge following treatment discontinuation induced additional tumor regression, suggesting lack of treatment resistance. In a mouse model with a humanized immune system resistant to PD-1 inhibition, OMTX705 increased tumor infiltration by CD8⁺ T cells, induced complete regressions, and delayed tumor recurrence.

CONCLUSIONS

These data suggest that FAP targeting with OMTX705 represents a novel and potent strategy for cancer treatment, including tumors resistant to immunotherapy, and support its clinical development.

RAS-MAPK Reactivation Facilitates Acquired Resistance in FGFR1-Amplified Lung Cancer and Underlies a Rationale for Upfront FGFR-MEK Blockade

The FGFR kinases are promising therapeutic targets in multiple cancer types, including lung and head and neck squamous cell carcinoma, cholangiocarcinoma, and bladder cancer. Although several FGFR kinase inhibitors have entered clinical trials, single-agent clinical efficacy has been modest and resistance invariably occurs. We therefore conducted a genome-wide functional screen to characterize mechanisms of resistance to FGFR inhibition in a FGFR1-dependent lung cancer cellular model. Our screen identified known resistance drivers, such as MET, and additional novel resistance mediators including members of the neurotrophin receptor pathway (NTRK), the TAM family of tyrosine kinases (TYRO3, MERTK, AXL), and MAPK pathway, which were further validated in additional FGFR-dependent models. In an orthogonal approach, we generated a large panel of resistant clones by chronic exposure to FGFR inhibitors in FGFR1- and FGFR3-dependent cellular models and characterized gene expression profiles employing the L1000 platform. Notably, resistant clones had enrichment for NTRK and MAPK signaling pathways. Novel mediators of resistance to FGFR inhibition were found to compensate for FGFR loss in part through reactivation of MAPK pathway. Intriguingly, coinhibition of FGFR and specific receptor tyrosine kinases identified in our screen was not sufficient to suppress ERK activity or to prevent resistance to FGFR inhibition, suggesting a redundant reactivation of RAS-MAPK pathway. Dual blockade of FGFR and MEK, however, proved to be a more powerful approach in preventing resistance across diverse FGFR dependencies and may represent a therapeutic opportunity to achieve durable responses to FGFR inhibition in FGFR-dependent cancers. Mol Cancer Ther; 17(7); 1526-39. ©2018 AACR.

Suppression of Adaptive Responses to Targeted Cancer Therapy by Transcriptional Repression

Acquired drug resistance is a major factor limiting the effectiveness of targeted cancer therapies. Targeting tumors with kinase inhibitors induces complex adaptive programs that promote the persistence of a fraction of the original cell population, facilitating the eventual outgrowth of inhibitor-resistant tumor clones. We show that the addition of a newly identified CDK7/12 inhibitor, THZ1, to targeted therapy enhances cell killing and impedes the emergence of drug-resistant cell populations in diverse cellular and in vivo cancer models. We propose that targeted therapy induces a state of transcriptional dependency in a subpopulation of cells poised to become drug tolerant, which THZ1 can exploit by blocking dynamic transcriptional responses, promoting remodeling of enhancers and key signaling outputs required for tumor cell survival in the setting of targeted therapy. These findings suggest that the addition of THZ1 to targeted therapies is a promising broad-based strategy to hinder the emergence of drug-resistant cancer cell populations.Significance: CDK7/12 inhibition prevents active enhancer formation at genes, promoting resistance emergence in response to targeted therapy, and impedes the engagement of transcriptional programs required for tumor cell survival. CDK7/12 inhibition in combination with targeted cancer therapies may serve as a therapeutic paradigm for enhancing the effectiveness of targeted therapies. Cancer Discov; 8(1); 59-73. ©2017 AACR.See related commentary by Carugo and Draetta, p. 17This article is highlighted in the In This Issue feature, p. 1.

Abstract 15: Suppression of adaptive responses to targeted therapies by transcriptional inhibition

Tumor cells become dependent on the expression of key genes that drive hallmark tumor traits, but these “addictions” also represent potential vulnerabilities for therapeutic intervention. Treating tumor cells with a small molecule inhibitor of the transcriptional kinase CDK7 selectively suppresses expression of key dependency genes in multiple cancers. Our previous work showed responses to the CDK7 inhibitor THZ1 were especially noteworthy in T cell leukemias, small cell lung cancers, and triple-negative breast cancers—tumor types where the prognoses are especially unfavorable. The genes whose expression is most sensitive to CDK7 inhibition and whose expression is essential for tumor cell survival are often associated with super-enhancers—clusters of constituent enhancers that are bound by unusually large amounts of transcription apparatus including CDK7 itself. This “Achilles’ cluster” of super-enhancer-associated genes thus represents the set of addictions of tumor cells whose expression is important for tumor cell survival. Transcriptional inhibition synergizes with targeted therapies in models of multiple tumor types. Treating tumors with therapies that target kinase proteins such as EGFR, FGFR, and KRAS leads to resistance, which is concurrent with changes in the activities of enhancers and super-enhancers and gene expression programs of resistant cells. Treating cells with a transcriptional inhibitor in addition to targeted therapies prevents “rewiring” of the gene expression program and increases cell death in tumor models. Thus transcriptional inhibition represents a promising avenue in both monotherapy and combination settings where drug resistance is acquired.

Citation Format: Maria Rusan, Kapsok Li, Yvonne Li, Camilla L. Christensen, Brian J. Abraham, Nicholas Kwiatkowski, Kevin Buczkowski, Bruno Bockorny, Ting Chen, Shuai Li, Haikuo Zhang, Hideko Terai, Tiffany Tavares, Tinghu Zhang, Tae Jung Kim, Michael Silkes, Tenny Mudianto, Li Tan, Takeshi Shimamura, Matthew Meyerson, Hideo Watanabe, Nathanael S. Gray, Richard A. Young, Kwok-Kin Wong, Peter S. Hammerman. Suppression of adaptive responses to targeted therapies by transcriptional inhibition [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 15. doi:10.1158/1538-7445.AM2017-15

Enhancing targeted therapy of tumors with activating FGFR alterations

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Background: Emerging evidence points to the Fibroblast Growth Factor Receptor (FGFR) kinase family as a promising target in multiple cancer types including lung squamous cell carcinoma, cholangiocarcinoma, gastric, bladder and breast cancer. Although several FGFR kinase inhibitors have entered clinical trials, single agent clinical efficacy has been modest and resistance invariably occurs. A comprehensive understanding of the molecular basis of resistance to FGFR inhibitors is urgently needed to enable the successful application of anti-FGFR therapy in the clinic. Methods: We utilized a systematic genome-wide open reading frame (ORF) screen to identify genes whose upregulation confers resistance to the FGFR inhibitors BGJ398 and FIIN-3 in FGFR1-amplified H2077 lung cancer cells. In an orthogonal approach, we established resistant clones of FGFR1-amplified and FGFR3-translocated cell lines by chronic exposure to BGJ398, and characterized these by high-throughput gene expression analysis. Results: We identified 34 candidate genes, including expected findings such as a mutant KRAS allele and MET overexpression. Intriguingly, we also identified novel candidate resistance mechanisms involving the genes of the TAM family, which encode the transmembrane receptors Tyro3, Axl and Mertk. These tyrosine kinases may serve as a secondary target to augment FGFR therapy. We validated that the TAM family confers resistance to FGFR inhibitors in different FGFR dependencies including FGFR1-amplified lung cancer, FGFR2-amplified gastric and colon cancer and FGFR 3-translocated bladder cancer, with AXL having the greatest rescue. Notably, gene profiling of resistant clones also implicates the TAM family, with both receptors and their ligands upregulated in the majority cases. Moreover, concurrent TAM blockade augments the response to FGFR inhibition in vitro and provides a promising therapeutic strategy to overcome resistance. Conclusions: TAM kinases are important mediators of resistance to FGFR inhibitors and the dual blockade of FGFR and TAM provides a novel approach to enhance the efficacy of anti-FGFR therapy.

The emerging role of immunotherapy in gastric and esophageal adenocarcinoma

Gastric and esophageal adenocarcinomas are aggressive malignancies. Systemic therapy for these tumors relies primarily on cytotoxic chemotherapy but outcomes remain poor. In recent years, immunotherapy has emerged as a new, promising therapeutic approach for a variety of solid tumors. Characterization of gastroesophageal cancers has revealed genomic and immune features of these tumors that may predict response to immunotherapy. Indeed, preliminary results from the initial trials of immune checkpoint inhibitors have been encouraging, with objective response rates of 20% in heavily pretreated patient populations. Based on these results, additional trials of single-agent checkpoint inhibitors as well as combinations with chemotherapy and targeted therapies are currently ongoing. Further work to identify predictive biomarkers will be crucial for the successful implementation of immunotherapy.

Prevalence and Pattern of Autoimmune Conditions in Patients with Marginal Zone Lymphoma: A Single Institution Experience

BACKGROUND

Increased risk of B-cell non-Hodgkin lymphoma (NHL) in patients with autoimmune diseases is a known fact. An association may exist between marginal zone lymphoma (MZL) and certain autoimmune conditions and vice-versa.

METHODS

Herein, we present the analysis of a series of consecutive patients (n = 24) diagnosed with MZL at our institution between 2008-2014. Our series, analyzed both retrospectively and prospectively, consisted of a blend of nodal, extranodal and splenic MZL. The median age was 71.8 years; M/F ratio was 2:1. The presence of autoimmune conditions was compared to their documented prevalence in the general population and tested for statistical significance using both chi-square test (χ2) and Fisher test for small number of observations (95% confidence). A P-value < 0.05 was considered significant.

FINDINGS

A total of 50% of MZL patients had documented autoimmune conditions. In addition, 3 of 24 patients presented with more than one autoimmune disease. Statistically significant differences in our MZL patients were recorded for immune thrombocytopenia [ITP] (P < 0.01), autoimmune hemolytic anemia [AIHA] (P < 0.01), Hashimoto thyroiditis (P = 0.037) and rheumatoid arthritis [RA] (P = 0.021). The difference did not reach statistical significance for systemic lupus erythematosus (SLE) and psoriasis. ITP and AIHA in our cohort were synchronous with MZL diagnosis in all patients, while all non-hematologic autoimmune conditions were metachronous and diagnosed prior to MZL.

CONCLUSIONS

In the course of caring for patients with MZL, a number of associated autoimmune disorders are recognized. Knowing these entities is important not only for making a correct diagnosis, but also for being able to recognize certain clinical events occurring during the course of the disease. A catalogue of autoimmune disorders associated with this type of NHL is important as they can pose formidable clinical problems for the MZL patients and their physicians.

HMG-CoA reductase inhibitors as adjuvant treatment for hematologic malignancies: what is the current evidence?

Statins have been shown to possess properties that go beyond their lipid-lowering effects. These agents act on the mevalonate pathway and inhibit synthesis of cholesterol, geranylgeranyl pyrophosphate, and farnesyl pyrophosphate, which are necessary for posttranslational modification of the Rho, Rac, and Ras superfamily of proteins. Early phase studies have demonstrated that this modulation of cellular signaling can ultimately exert pro-apoptotic, anti-angiogenic, and immunomodulatory effects, and might even restore chemosensitivity in several hematologic cancers. Nonetheless, these promising preclinical results have not yet migrated from the bench to the bedside as their effectiveness as adjuvant agents in hematologic malignancies is currently uncertain. In the present review, we summarize the existing evidence stemming from preclinical and clinical studies pertaining to the use of statins as adjuvant therapies in hematologic malignancies, and discuss the new insights gained from the ongoing translational research.

Pyoderma gangrenosum due to lenalidomide use for multiple myeloma

Pyoderma gangrenosum has been described in association with multiple myeloma and usually affects patients with active/untreated disease. This dermatologic condition was shown to resolve after successful anti-myeloma therapy. We report herein occurrence of pyoderma gangrenosum involving bilateral knees in a patient with multiple myeloma responding to lenalidomide therapy. Previous papers claimed usefulness of thalidomide and its newer derivatives for the therapy of this neutrophilic dermatosis. Occurrence of pyoderma gangrenosum in a myeloma patient responding to lenalidomide would argue against its effectiveness in treating this skin condition. Moreover, the clinical setting suggested that lenalidomide either induced or contributed to the occurrence of pyoderma gangrenosum in our patient. If our hypothesis is correct, we expect more reports of pyoderma gangrenosum with the use of this class of pharmaceuticals.

Recurrent pseudocellulitis due to gemcitabine: underrecognized and underreported?

Pseudocellulitis has been previously described with the use of chemotherapy agent gemcitabine. This condition is thought to occur due to vascular toxicity and increased localized permeability of the skin capillaries. We report herein a case of recurrent pseudocellulitis due to gemcitabine in a patient with metastatic pancreatic cancer. We believe this condition is underreported and underrecognized. Furthermore, it may be misdiagnosed as cellulitis and inappropriately treated with systemic antibiotics. As the diagnosis is clinical and the condition is self-limited, referral to other specialists is usually not required. Awareness of gemcitabine-induced pseudocellulitis is important in order to reassure the patients, their families, and non-oncology providers and to avoid unnecessary (and often costly) diagnostic work-up.

Pulmonary hemorrhage with capillaritis secondary to mycophenolate mofetil in a heart-transplant patient

Immunosuppressive drugs are an integral part of therapy in organ transplantation. However, they are not without side effects, and although rare, these agents should be considered in the differential diagnosis of pulmonary complications in patients receiving transplants. We present a case of a patient who developed acute respiratory failure 7 days after orthotopic heart transplantation and who had been on both mycophenolate mofetil (MMF) and tacrolimus agents. Lung biopsy revealed features of pulmonary hemorrhage with capillaritis. Considered as a possible etiology, MMF was withdrawn. There was immediate improvement of the patient's symptoms. The temporal relationship between MMF exposure and onset of pulmonary symptoms in the absence of other possible etiologies strongly suggests a causal relationship. Previously published reports of pulmonary toxicity from MMF included interstitial fibrosis. To the best of our knowledge, this is the first reported case of pulmonary hemorrhage with capillaritis because of administration of MMF.

Methotrexate therapy leading to a rapid progression of a previously indolent prostate cancer: is immunosuppression to blame?

Methotrexate therapy has been associated with occurrence and/or accelerated progression of malignancies. We describe a patient who developed widespread bone metastases of a previously confined to the prostate gland prostate cancer shortly after starting methotrexate therapy for rheumatoid arthritis and large granular lymphocyte leukemia. We believe an immunosuppressive milieu brought on by the methotrexate use in this case is responsible for the rapid progression of prostate cancer leading to the patient's demise. To the best of our knowledge, no association has been made to date between the therapy with methotrexate and a fulminant course of a previously indolent prostate cancer. Given its utilization in a variety of benign and malignant conditions and the ageing population, caution is advised with the use of this agent, especially in the presence of an underlying malignancy.

Intrinsic immune alterations in renal cell carcinoma and emerging immunotherapeutic approaches

INTRODUCTION

Individuals affected by kidney cancer present a variety of immune abnormalities including cellular immune dysfunction, cytokine alterations and antigen presentation defects. On the other hand, spontaneous remissions are seen in up to 4% of renal cell carcinoma (RCC) patients and they are thought to occur via immune mechanisms.

AREAS COVERED

The authors comprehensively review the immune abnormalities in RCC patient and describe the kidney cancer immunotherapy candidates that are most advanced in their clinical development. Most relevant publications were identified through searching the PubMed database; the obtained information was thoroughly analyzed and synthesized.

EXPERT OPINION

As cure in advanced RCC cannot be accomplished with the current therapy standards such as tyrosine kinase inhibitors and mammalian target of rapamycin inhibitors, new treatment strategies are being sought. Enhancing the immune system represents an appealing avenue for kidney cancer therapy. Disappointingly, high-dose interleukin-2 and interferon-α cause severe toxicity and produce a questionable clinical benefit. The authors postulate that the 'durable responses' seen with these agents in only a handful of RCC patients represent spontaneous remissions. Promising immune strategies in RCC such as anti-cytotoxic T-lymphocyte-associated protein antibodies, anti-programmed cell death 1 (PD1)/PD1 ligand and tumor vaccines may expand the existing options for kidney cancer in future years.

Autoimmune manifestations in large granular lymphocyte leukemia

Large granular lymphocyte (LGL) leukemia features a group of indolent lymphoproliferative diseases that display a strong association with various autoimmune conditions. Notwithstanding, these autoimmune conditions have not been comprehensively characterized or systematized to date. As a result, their clinical implications remain largely unknown. The authors offer a comprehensive review of the existing literature on various autoimmune conditions documented in the course of T-cell LGL (T-LGL) leukemia. Though some of them are thought be secondary to the LGL leukemia, others could be primary and might even play a role in its pathogenesis. A considerable clinico-laboratory overlap between T-LGL leukemia associated with rheumatoid arthritis and Felty's syndrome suggests that they are just different eponyms for the same clinical entity.

Prevalence of autoimmune conditions in patients with marginal zone lymphoma: Exploratory analysis of a series of consecutive patients

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Background: Recent literature suggests that an association exists between marginal zone lymphoma (MZL) and certain autoimmune conditions. Furthermore, MZL and autoimmune diseases may share same pathogenesis in these patients. The present study was set to identify the prevalence of autoimmune phenomena in MZL patients and compare it with same in general population. Methods: We conducted both retrospective and prospective analyses in a series of consecutive patients (n=24) with MZL that had been followed in outpatient setting. Median age was 71.8 years (range, 50-96). Records were reviewed for the presence of autoimmune abnormalities; length of the prospective analysis segment was ~24 months. Prevalence of autoimmune disorders in our cohort was compared to their respective prevalence in general population. Statistical analysis: The obtained values were tested for statistical significance using Fisher’s exact test for small number of observations (95% confidence); a p-value < 0.05 was considered significant. Results: A total of 50% patients included in our study had documented autoimmune conditions. Identified autoimmune disorders included Hashimoto thyroiditis (n=5), immune thrombocytopenia [ITP] (n=4), rheumatoid arthritis [RA] (n=1), Raynaud's phenomena (n=1), psoriasis (n=1), and autoimmune hemolytic anemia [AIHA] (n=1). Statistical analysis showed the following significance: Hashimoto thyroiditis (p=0.037), ITP (p<0.01), AIHA (p<0.01), RA(p=0.351), psoriasis (p=0.479), and Raynaud's phenomena (p=0.666). Conclusions: Circa half of MZL patients also have autoimmune conditions, thus significantly exceeding the overall prevalence in general population. Statistically significant differences in our MZL patients were recorded for Hashimoto thyroiditis, ITP, and AIHA. When compared to the prevalence in general population, the difference did not reach statistical significance for RA, psoriasis, and Raynaud's phenomena. However, this may be related to the relatively small size of the analyzed cohort. Therefore, larger studies would be useful before definitive conclusions can be drawn.