Augmenting antibody response to EGF-depleting immunotherapy: Findings from a phase I trial of CIMAvax-EGF in combination with nivolumab in advanced stage NSCLC

Background

CIMAvax-EGF is an epidermal growth factor (EGF)-depleting immunotherapy which has shown survival benefit as a switch maintenance treatment after platinum-based chemotherapy in advanced non-small cell lung cancer (NSCLC). The primary objective of this trial is to establish the safety and recommended phase II dose (RP2D) of CIMAvax-EGF in combination with nivolumab as second-line therapy for NSCLC.

Methods

Patients with immune checkpoint inhibitor-naive metastatic NSCLC were enrolled using a “3+3” dose-escalation design. Toxicities were graded according to CTCAE V4.03. Thirteen patients (one unevaluable), the majority with PD-L1 0%, were enrolled into two dose levels of CIMAvax-EGF.

Findings

The combination was determined to be safe and tolerable. The recommended phase 2 dose of CIMAvax-EGF was 2.4 mg. Humoral response to CIMAvax-EGF was achieved earlier and in a greater number of patients with the combination compared to historical control. Four out of 12 evaluable patients had an objective response.

Abstract CT145: Systemic rintatolimod and interferon-α2b selectively reprogram local tumor microenvironment in patients with metastatic triple negative breast cancer for enhanced influx of cytotoxic T-lymphocytes but not regulatory T-cells

Background: Effective immune therapies depend on the presence of cytotoxic T-lymphocytes (CTLs) in the tumor microenvironment (TME). Our preclinical data showed synergy between TLR3 ligands and interferon-α (IFN-α) in reprogramming the TME, but not healthy tissues, to selectively enhance CTL attraction, providing rationale for their systemic application to enhance local CTL densities in “cold” tumors. The pilot study NCT03599453 evaluated the safety of systemic chemokine modulating regimen (CKM) composed of i.v. rintatolimod (Ampligen; selective TLR3 ligand) and IFN-α, and its ability to promote local CTL influx to mTNBC lesions.

Methods: Six evaluable patients (33-75 years) with mTNBC received 6 doses of rintatolimod (200 mg i.v.), IFN-α (INTRON-A; 20MU/m2 i.v.) and COX-2 inhibitor (celecoxib; 2 x 200 mg, p.o.) over 2 weeks, with tumor biopsies obtained before (within 6 days) and after (within 5 days) CKM. All patients received follow-up pembrolizumab (200 mg, i.v, Q3 weeks). The primary endpoint was the change in the CTL marker CD8α in the TME with a planned interim analysis after 3 patients (α=0.03) and final analysis after 6 patients (α=0.084). Correlative studies analyzed additional markers of CTLs, regulatory T-cells (Tregs), and CTL- and Treg-attracting chemokines in the TME and blood.

Results: Treatment was well tolerated with mostly grade 1/2 adverse events and one grade 3 clinically significant pneumonitis and immune thrombocytopenic purpura observed during follow up pembrolizumab treatment. We observed uniform increases of intratumoral type-1 immune markers upon treatment: CD8α mRNA (6.1-fold; p=0.034), GZMB (3.5-fold; p=0.058), ratios of CD8α/FOXP3 and GZMB/FOXP3 (5.7-fold; p=0.036, and 7.6-fold; p=0.024 respectively), and CTL attractants CXCL10 (2.6-fold; p=0.104) and CCL5 (3.3-fold; p=0.019), successfully meeting the primary endpoint. In contrast, neither Treg marker Foxp3 nor Treg attractants CCL22 or CXCL12 were enhanced. These TME changes were accompanied by transient decreases in circulating CD3+CD8+ CTLs and CD3-CD56+ NK cells (but not Tregs), selectively affecting the cells expressing CXCR3 (receptor for CXCL10), but not CCR4 or CXCR4 (receptors for CCL22 and CXCL12). Three patients had stable disease lasting 2.4, 2.5 and 3.8 months, as of September 1, 2021 cut-off. An additional patient had a partial response (breast auto-amputation) with massive tumor necrosis observed in the post-CKM biopsy.

Conclusion: This proof-of-concept study shows that short-term systemic CKM followed by pembrolizumab is safe and selectively enhances local CTL infiltration in the TME, providing rationale for concurrent CKM and PD1 blockade in prospective phase II studies.

Citation Format: Shipra Gandhi, Mateusz Opyrchal, Melissa Grimm, Ronald Slomba, Kathleen Kokolus, Sebastiano Battaglia, Kristopher Attwood, Adrienne Groman, Lauren Williams, Mary Lynne Tarquini, Paul Wallace, Kah Teong Soh, Tracey O'Connor, Amy Early, Ellis Levine, Igor Puzanov, Marc Ernstoff, Pawel Kalinski. Systemic rintatolimod and interferon-α2b selectively reprogram local tumor microenvironment in patients with metastatic triple negative breast cancer for enhanced influx of cytotoxic T-lymphocytes but not regulatory T-cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT145.

Cardiovascular adverse events are associated with usage of immune checkpoint inhibitors in real-world clinical data across the United States

Background

Immune checkpoint inhibitors (ICIs) can cause life-threatening cardiovascular adverse events (CVAEs) that may not be attributed to therapy. The outcomes of clinical trials may underestimate treatment-related adverse events due to restrictive eligibility, limited sample size, and failure to anticipate selected toxicities. We evaluated the incidence and clinical determinants of CVAEs in real-world population on ICI therapy.

Patients and methods

Among 2 687 301 patients diagnosed with cancer from 2011 to 2018, 16 574 received ICIs for any cancer. Patients in the ICI and non-ICI cohorts were matched in a 1 : 1 ratio according to age, sex, National Cancer Institute comorbidity score, and primary cancer. The non-ICI cohort was stratified into patients who received chemotherapy (N = 2875) or targeted agents (N = 4611). All CVAEs, non-cardiac immune-related adverse events occurring after treatment initiation, baseline comorbidities, and treatment details were identified and analyzed using diagnosis and billing codes.

Results

Median age was 61 and 65 years in the ICI and non-ICI cohorts, respectively (P < 0.001). ICI patients were predominantly male (P < 0.001). Lung cancer (43.1%), melanoma (30.4%), and renal cell carcinoma (9.9%) were the most common cancer types. CVAE diagnoses in our dataset by incidence proportion (ICI cohort) were stroke (4.6%), heart failure (3.5%), atrial fibrillation (2.1%), conduction disorders (1.5%), myocardial infarction (0.9%), myocarditis (0.05%), vasculitis (0.05%), and pericarditis (0.2%). Anti-cytotoxic T-lymphocyte-associated protein 4 increased the risk of heart failure [versus anti-programmed cell death protein 1; hazard ratio (HR), 1.9; 95% confidence interval (CI) 1.27-2.84] and stroke (HR, 1.7; 95% CI 1.3-2.22). Pneumonitis was associated with heart failure (HR, 2.61; 95% CI 1.23-5.52) and encephalitis with conduction disorders (HR, 4.35; 95% CI 1.6-11.87) in patients on ICIs. Advanced age, primary cancer, nephritis, and anti-cytotoxic T-lymphocyte-associated protein 4 therapy were commonly associated with CVAEs in the adjusted Cox proportional hazards model.

Conclusions

Our findings underscore the importance of risk stratification and cardiovascular monitoring for patients on ICI therapy.

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Patient claims data across the United States were used to study cardiovascular adverse events (CVAEs) after ICI treatment.

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Patients on ICI treatment for advanced cancer have a higher incidence of CVAEs than previously reported.

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Median time to CVAE onset was significantly shorter with ICIs (~3 months) than with non-ICI systemic therapy (~8 months).

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Anti-CTLA-4 monotherapy or combination had a higher risk of heart failure and stroke than anti-PD-1 therapy (1.5-2 folds).

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Age, male sex, cancer type, nephritis, pneumonitis, and anti-CTLA-4 therapy were associated with a higher risk of CVAEs.

Rechallenge patients with immune checkpoint inhibitors following severe immune-related adverse events: review of the literature and suggested prophylactic strategy

Patients with cancer who developed severe, grade 3 or 4 immune-related adverse events (irAEs) during therapy with immune checkpoint inhibitors are at risk for developing severe toxicities again on rechallenge with checkpoint inhibitors. Consequently, medical oncologists and multidisciplinary teams are hesitant to retreat in this scenario, despite the fact that a number of patients may derive clinical benefit from this approach. Balancing such clinical benefit and treatment-related toxicities for each patient is becoming increasingly challenging as more and more patients with cancer are being treated with checkpoint inhibitors. In this manuscript, we provide an extensive overview of the relevant literature on retreatment after toxicity, and suggest prophylactic approaches to minimize the risk of severe irAE following rechallenge with immune checkpoint blockade, since treatment may be lifesaving in a number of occasions.

Perspectives in melanoma: meeting report from the "Melanoma Bridge" (December 5th-7th, 2019, Naples, Italy)

The melanoma treatment landscape changed in 2011 with the approval of the first anti-cytotoxic T-lymphocyte-associated protein (CTLA)-4 checkpoint inhibitor and of the first BRAF-targeted monoclonal antibody, both of which significantly improved overall survival (OS). Since then, improved understanding of the tumor microenvironment (TME) and tumor immune-evasion mechanisms has resulted in new approaches to targeting and harnessing the host immune response. The approval of new immune and targeted therapies has further improved outcomes for patients with advanced melanoma and other combination modalities are also being explored such as chemotherapy, radiotherapy, electrochemotherapy and surgery. In addition, different strategies of drugs administration including sequential or combination treatment are being tested. Approaches to overcome resistance and to potentiate the immune response are being developed. Increasing evidence emerges that tissue and blood-based biomarkers can predict the response to a therapy. The latest findings in melanoma research, including insights into the tumor microenvironment and new biomarkers, improved understanding of tumor immune response and resistance, novel approaches for combination strategies and the role of neoadjuvant and adjuvant therapy, were the focus of discussions at the Melanoma Bridge meeting (5-7 December, 2019, Naples, Italy), which are summarized in this report.

Abstract 1044: Frequency of circulating CX3CR1+ CD8+ T cells to predict response to immune checkpoint inhibitor therapy

While immune checkpoint inhibitors (ICI) have revolutionized treatment for various cancers including non-small cell lung cancer (NSCLC), only a subset of patients receives durable clinical benefit. Discovery of blood-based biomarkers that reflect dynamic change of tumor microenvironment, and predict response to ICI will markedly improve current treatment regimens. Emerging evidence has shown that the frequency of peripheral blood (PB) CD8+ T cells expressing CX3CR1, a marker of effector T-cell differentiation increases in patients receiving ICI. However, no studies have rigorously evaluated the utility of CX3CR1 as a PB biomarker to predict response to ICI, and identify responders and non-responders. Here, we evaluated the utility of circulating T-cell biomarkers to predict response to ICI therapy in preclinical models and NSCLC patients (n=35). We found successful treatment with ICI significantly increases the frequency of PB CX3CR1+ CD8+ T-cell subsets that enrich neoantigen- as well as shared tumor-associated antigen-specific T cells in mice bearing MC38 and CT26 colon adenocarcinoma. Significantly increased expression of IFN-γ and Ki67 suggests that these subsets are highly proliferative effector CD8+ T cells. Interestingly, upregulation of Ki67 was transient; however, expression of CX3CR1 remained high on tumor-specific tetramer+ CD8+ T cells. Moreover, high-throughput sequencing of the T-cell receptor (TCR) identified significantly higher clonality and overlapping TCR repertoires in between peripheral CX3CR1+ CD8+ T cells and CD8+ tumor-infiltrating lymphocytes (TILs), suggesting the potential utility as a dynamic biomarker early on-treatment. Most importantly, changes in the frequency of PB CX3CR1+ CD8+ T cells associate with response to ICI therapy in individual mice. Phenotypic analysis of PB CD8+ T cells from 35 NSCLC patients undergoing PD-1/PD-L1 blockade revealed that the maximum percent change of these T-cell subsets from baseline identified responders and non-responders as early as 3 weeks from the initiation of ICI therapy with higher sensitivity, specificity, positive and negative predictive value compared to PD-L1 expression in the tumor, tumor mutational burden, and pre-existing TILs. Importantly, TCR sequencing confirmed clonally-expanding TCR repertoires within the T-cell subsets that were also found in TILs. Collectively, the frequency of circulating CX3CR1+ CD8+ T cells correlates with response to ICI therapy, and identifies responders vs non-responders early on-treatment. These findings provide a solid foundation for future development of clinical trials with large cohorts of patients undergoing ICI therapy not only for NSCLC, but also for a wide variety of malignancies.

Citation Format: Takayoshi Yamauchi, Toshifumi Hoki, Takaaki Oba, Kristopher Attwood, Sebastiano Battaglia, Igor Puzanov, Hongbin Chen, Grace Dy, Brahm Segal, Marc Ernstoff, Fumito Ito. Frequency of circulating CX3CR1+ CD8+ T cells to predict response to immune checkpoint inhibitor therapy [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 1044.

Ipilimumab plus nivolumab for patients with metastatic uveal melanoma: a multicenter, retrospective study

BACKGROUND

Uveal melanoma (UM) is the most common intraocular malignancy in adults. In contrast to cutaneous melanoma (CM), there is no standard therapy, and the efficacy and safety of dual checkpoint blockade with nivolumab and ipilimumab is not well defined.

METHODS

We conducted a retrospective analysis of patients with metastatic UM (mUM) who received treatment with ipilimumab plus nivolumab across 14 academic medical centers. Toxicity was graded using National Cancer Institute Common Terminology Criteria for Adverse Events V.5.0. Progression-free survival (PFS) and overall survival (OS) were calculated using Kaplan-Meier methodology.

RESULTS

89 eligible patients were identified. 45% had received prior therapy, which included liver directed therapy (29%), immunotherapy (21%), targeted therapy (10%) and radiation (16%). Patients received a median 3 cycles of ipilimumab plus nivolumab. The median follow-up time was 9.2 months. Overall response rate was 11.6%. One patient achieved complete response (1%), 9 patients had partial response (10%), 21 patients had stable disease (24%) and 55 patients had progressive disease (62%). Median OS from treatment initiation was 15 months and median PFS was 2.7 months. Overall, 82 (92%) of patients discontinued treatment, 34 due to toxicity and 27 due to progressive disease. Common immune-related adverse events were colitis/diarrhea (32%), fatigue (23%), rash (21%) and transaminitis (21%).

CONCLUSIONS

Dual checkpoint inhibition yielded higher response rates than previous reports of single-agent immunotherapy in patients with mUM, but the efficacy is lower than in metastatic CM. The median OS of 15 months suggests that the rate of clinical benefit may be larger than the modest response rate.

Ex vivo conditioning with IL-12 protects tumor-infiltrating CD8+ T cells from negative regulation by local IFN-γ

Optimal ex vivo expansion protocols for adoptive cell therapy (ACT) must yield T cells able to effectively home to tumors and survive the inhospitable conditions of the tumor microenvironment (TME), while simultaneously exerting persistent anti-tumor effector functions. Our previous work has shown that ex vivo activation in the presence of IL-12 can induce optimal expansion of murine CD8+ T cells, thus resulting in significant tumor regression after ACT mostly via sustained secretion of IFN-γ. In this report, we further elucidate the mechanism of this potency, showing that IL-12 additionally counteracts the negative regulatory effects of autocrine IFN-γ. IL-12 not only downregulates PD-1 expression by T cells, thus minimizing the effects of IFN-γ-induced PD-L1 upregulation by tumor stromal cells, but also inhibits IFNγR2 expression, thereby protecting T cells from IFN-γ-induced cell death. Thus, the enhanced anti-tumor activity of CD8+ T cells expanded ex vivo in the presence of IL-12 is due not only to the ability of IL-12-stimulated cells to secrete sustained levels of IFN-γ, but also to the additional capacity of IL-12 to counter the negative regulatory effects of autocrine IFN-γ.

Proliferative potential and resistance to immune checkpoint blockade in lung cancer patients

Background

Resistance to immune checkpoint inhibitors (ICIs) has been linked to local immunosuppression independent of major ICI targets (e.g., PD-1). Clinical experience with response prediction based on PD-L1 expression suggests that other factors influence sensitivity to ICIs in non-small cell lung cancer (NSCLC) patients.

Methods

Tumor specimens from 120 NSCLC patients from 10 institutions were evaluated for PD-L1 expression by immunohistochemistry, and global proliferative profile by targeted RNA-seq.

Results

Cell proliferation, derived from the mean expression of 10 proliferation-associated genes (namely BUB1, CCNB2, CDK1, CDKN3, FOXM1, KIAA0101, MAD2L1, MELK, MKI67, and TOP2A), was identified as a marker of response to ICIs in NSCLC. Poorly, moderately, and highly proliferative tumors were somewhat equally represented in NSCLC, with tumors with the highest PD-L1 expression being more frequently moderately proliferative as compared to lesser levels of PD-L1 expression. Proliferation status had an impact on survival in patients with both PD-L1 positive and negative tumors. There was a significant survival advantage for moderately proliferative tumors compared to their combined highly/poorly counterparts (p = 0.021). Moderately proliferative PD-L1 positive tumors had a median survival of 14.6 months that was almost twice that of PD-L1 negative highly/poorly proliferative at 7.6 months (p = 0.028). Median survival in moderately proliferative PD-L1 negative tumors at 12.6 months was comparable to that of highly/poorly proliferative PD-L1 positive tumors at 11.5 months, but in both instances less than that of moderately proliferative PD-L1 positive tumors. Similar to survival, proliferation status has impact on disease control (DC) in patients with both PD-L1 positive and negative tumors. Patients with moderately versus those with poorly or highly proliferative tumors have a superior DC rate when combined with any classification schema used to score PD-L1 as a positive result (i.e., TPS ≥ 50% or ≥ 1%), and best displayed by a DC rate for moderately proliferative tumors of no less than 40% for any classification of PD-L1 as a negative result. While there is an over representation of moderately proliferative tumors as PD-L1 expression increases this does not account for the improved survival or higher disease control rates seen in PD-L1 negative tumors.

Conclusions

Cell proliferation is potentially a new biomarker of response to ICIs in NSCLC and is applicable to PD-L1 negative tumors.

Electronic supplementary material

The online version of this article (10.1186/s40425-019-0506-3) contains supplementary material, which is available to authorized users.

Abstract 4526: Predicting response: PD-L1 biomarker testing by IHC and RNA-seq

Background: Currently, four FDA-approved biomarker assays are available to screen for PD-L1 to enrich for patient response to checkpoint inhibitors (CPI). Each are immunohistochemical (IHC) assays that approximate the percentage of immune or tumor cells expressing PD-L1 using various antibodies, staining and scoring systems. Given this inherent variability, there are concerns whether any single PD-L1 IHC assay, or IHC in general, can be used as a companion or complimentary diagnostic. This is highlighted by the number of individuals, regardless of histology or antibody used, who score below the IHC scoring threshold but respond to PD-L1 inhibitors.

Methods: In this study, we compared PD-L1 protein expression (IHC) to PD-L1 gene expression (CD274) in 436 tumors. PD-L1 IHC was assessed in melanoma using the 28-8 antibody, with kidney, HNSCC, and lung cancer assessed with 22C3. All were scored as per published guidelines. CD274 gene expression was determined by targeted RNA-seq, with each sample's expression level compared and ranked to a reference population.

Results: ANOVA demonstrated a significant relationship between RNA-seq and IHC PD-L1 measurements (p.value &lt; 2e-16). Tukey's HSD comparisons of mean TPS at &lt;1%, 1-4%, and &gt;5% demonstrate significant differences between the three groups that are consistent with gene expression rankings (p adj &lt;0.002). Additionally, for metastatic melanomas with CPI response data, a strong association of objective response rate (ORR) to high RNA-seq expression exists, regardless of IHC result (Table 1). Conclusion: In 400+ tumors, PD-L1 demonstrates correlated mean expression values when assessing protein by IHC and gene expression by RNA-seq. For the CPI treated melanomas with outcomes, PD-L1 IHC ≥1% had a 56% ORR, which improved to &gt;71% ORR when combined with high PD-L1 gene expression. With the need to better predict CPI response, this data suggests that combination PD-L1 testing is an improvement over the FDA approved IHC assays.

Table 1: ORR for 37 melanoma patients based on combination PD-L1 expression resultsPD-L1 Method CombinationsCRPRSDPDORR95% CIRNAseq High + IHC ≥1%141171.4%29.04%-96.33%RNAseq High + IHC &lt;1%120175.0%19.41%-99.37%RNAseq Low + IHC ≥1%101050.0%1.26%-98.74%RNAseq Low + IHC &lt;1%0541520.8%7.13%-42.15%

Citation Format: Jeffrey Conroy, Sarabjot Pabla, Mary Nesline, Sean Glenn, Blake Burgher, Maochun Qin, Jonathan Andreas, Vincent Giamo, Felicia L. Lenzo, Angela Omilian, Wiam Bshara, Antonios Papanicolau-Sengos, Yirong Wang, Marc Ernstoff, Mark Gardner, Carl Morrison. Predicting response: PD-L1 biomarker testing by IHC and RNA-seq [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 4526.

Abstract 5070: Chemokine expression signatures in infiltrated vs non-infiltrated tumors

Background: Previous studies in animal models have shown that expression of specific chemokines determines immune cell infiltration in the tumor microenvironment. More specifically, low expression of CXCL9/10/11, CXCR3, and CCL5, coupled with high expression of CCL2, CCR2, CCR4, CCR5, CCL22, CXCL12, and CXCR4, leads to an exclusion of effector T-cells in the tumor microenvironment while allowing the entry of Treg and MDSC(s).

Methods: 300 formalin-fixed, paraffin-embedded (FFPE) metastatic cutaneous melanoma samples were evaluated by the RNA-seq component of a comprehensive immune profile panel to measure transcript levels of chemokine genes. Resultant data was QC filtered, normalized and ranked based on an assorted reference population of various tumor types. CD8 expression was used to categorize tumors as inflamed (CD8 Rank ≥ 75), borderline ≥ 25 CD8 Rank &lt; 75) and immune deserts (CD8 Rank &lt; 25). T-cell infiltration is defined by CD8 immunohistochemistry with following definitions: Noninfiltrated - Sparse number of CD8+ T-cells that infiltrate nests of neoplastic cells and represent less than 5% of the tumor. Infiltrated - Frequent CD8+ Tcells that infiltrate nests of neoplastic cells in an overlapping fashion at least focally and represent more than 50% of the tumor cells.

Results: CD8 infiltration by immunohistochemistry showed high correlation with CD8 gene expression by RNAseq with infiltrated tumors showing significantly higher expression of CD8 than non-infiltrated tumors (v.test:9.47, p= 2.79E-21; Wilcoxon rank sum test p&lt;0.05). Moreover, 73% of inflamed tumors were categorized as “infiltrated” by IHC while 93% of Immune desert tumors were categorized as “non-infiltrated” by IHC. Chemokine expression significantly correlated with infiltration status by IHC, wherein, CCL5, CCR5, CCL4, CXCR3, CXCL9, CCL2, CCL22, CCL3, and CXCL10 were significantly under expressed in tumors lacking infiltrating effector T-cells (Wilcoxon rank sum test p&lt;0.05, Tukey HSD adjusted p &lt;0.001). Overall ANOVA results showed significant relationship between gene expression of these chemokines and Infiltration status by CD8 IHC (p &lt;0.05).

Conclusion: In 300 metastatic cutaneous melanoma cases, we demonstrated that tumor inflammation status by CD8 expression by RNAseq correlated with CD8 infiltration pattern by IHC. Moreover, expression of Infiltrated and non-infiltrated tumors shows distinct chemokine signatures where higher CD8 T-cell infiltration correlates with higher expression of studied chemokines in the tumor microenvironment. It requires further investigation to better understand the interplay of chemokines and cytokines in the tumor microenvironments that drive the immune cycle in melanoma.

Citation Format: Sarabjot Pabla, Jeffrey Conroy, Mary Nesline, Sean Glenn, Blake Burgher, Maochun Qin, Jonathan Andreas, Vincent Giamo, Felicia L. Lenzo, Angela Omilian, Wiam Bshara, Antonios Papanicolau-Sengos, Yirong Wang, Marc Ernstoff, Mark Gardner, Carl Morrison. Chemokine expression signatures in infiltrated vs non-infiltrated tumors [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 5070.

Abstract 3682: Expression levels of genes in primary melanoma associated with clinically meaningful characteristics

Melanoma survival appears to be improving; however, between 13-68% of individuals with melanoma diagnosed with Stages II-III ultimately die from their melanoma. Factors influencing melanoma survival include sex, age, clinical stage, lymph node involvement and several primary tumor characteristics, such as Breslow thickness, presence of infiltrating lymphocytes (TILs), mitotic rate and ulceration. Identification of genes whose expression in primary tumors is associated with these key tumor/patient characteristics can shed light on molecular mechanisms of melanoma survival. Here we show results from a gene expression analysis of 32 formalin-fixed, paraffin embedded (FFPE) primary melanomas with extensive clinical annotation. We extracted RNA, and measured the expression of 760 genes selected based on published evidence of association with melanoma initiation or outcome using NanoString. The Cancer Genome Atlas (TCGA) data on primary melanomas was used for validation of nominally significant associations. We identified 5 genes that were significantly associated with the presence of TILs in the combined analysis of both datasets after adjustment for multiple testing using the Benjamini-Hochberg false discovery rate method: IL1R2, PPL, PLA2G3, RASAL1, and SGK2. We also identified two genes significantly associated with lymph node status (PIK3CG and IL2RA), and two genes significantly associated with sex (KDM5C and KDM6A). We found that LEF1 was significantly associated with Breslow thickness and CCNA2 with mitosis. These results demonstrate that genetic expression in primary tumors is associated with clinically meaningful characteristics of cutaneous melanoma.

Citation Format: Marianne Berwick, Ivan P. Gorlov, Irene Orlow, Carol Ringelberg, Marc Ernstoff, Joel Parker, Meg Gerstenblith, Cheryl Thompson, Eva Hernando, Klaus Busam, Cecilia Lezcano, Sergio Corrales, Siok Leong, Nancy E. Thomas, Christopher I. Amos. Expression levels of genes in primary melanoma associated with clinically meaningful characteristics [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 3682.

Abstract 3679: PD-L1 driven excluded phenotype in melanoma

Background: The excluded phenotype has been previously described by the presence of abundant immune cells that do not penetrate the parenchyma of these tumors but instead are retained in the stroma that surrounds nests of tumor cells. These features support a pre-existing anti-tumor immune-related response, but the details of this mechanism are not well elucidated.

Methods: 300 formalin-fixed, paraffin-embedded (FFPE) metastatic cutaneous melanoma samples were evaluated by the RNA-seq component of a comprehensive immune profile panel to measure transcript levels of immune-related genes. Resultant data was QC filtered, normalized and ranked based on an assorted reference population of various tumor types. The expression of PD-L1 on the surface of tumor cells was assessed in tumor samples by means of an automated IHC assay (28-8, Dako). A tumor was considered PD-L1 positive if ≥1% of viable tumor cells exhibited complete circumferential or partial linear plasma membrane staining at any intensity. Excluded pattern of T-cell infiltration was defined by CD8 immunohistochemistry by the following definition: Restriction of more than 95% of all CD8+ T-cells present in a tumor to the periphery or interstitial stromal areas and not actively invading nest or groups of neoplastic cells.

Results: The excluded phenotype was identified in 34 of 300 (11%). PD-L1 by IHC was positive (≥1%) in the neoplastic cases in 16 of 34 (47%) cases. Membranous staining in immune cells was identified in only 3 of 34 (9%) cases, but was present in &gt;90% of all cases in a non-membranous pattern. In more than one-half of all cases the non-membranous pattern of PD-L1 IHC staining was restricted to the excluded TILs. Higher expression of PD-L1 by RNA-seq was associated with this excluded PD-L1 pattern of staining.

Conclusion: In 300 metastatic cutaneous melanoma cases we demonstrated that the excluded phenotype is frequent and represents ~10% of all cases. Moreover, in a significant number of excluded cases expression of PD-L1 by IHC was distinctly limited to the excluded TILs. This finding would support a unique mechanism of PD-L1 anti-tumor immune-related response that needs further investigation.

Citation Format: Carl Morrison, Jeffrey Conroy, Mary Nesline, Sean Glenn, Blake Burgher, Maochun Qin, Jonathan Andreas, Vincent Giamo, Felicia L. Lenzo, Angela Omilian, Wiam Bshara, Antonios Papanicolau-Sengos, Yirong Wang, Marc Ernstoff, Mark Gardner, Sarabjot Pabla. PD-L1 driven excluded phenotype in melanoma [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 3679.

Abstract 1625: NGS reveals specimen characteristics have minimal impact on immune gene expression signature

Background: Therapeutic antibodies targeting immune checkpoint molecules have been approved by the FDA for the treatment of several types of cancer. Currently, evaluation of the tumor checkpoint blockade is limited to FDA-approved IHC assays measuring PD-L1 ligand status which is subjective and not analytically robust. As the number of antibodies targeting immune checkpoints expands, assays that can evaluate additional biomarkers in tumor specimens are needed to accurately predict patient response to these drugs. To address these issues, a custom immune response NGS assay was developed to measure the transcript level of 54 genes involving T-cell receptor signaling (TCRS) and tumor infiltrating lymphocytes (TILs) in solid tumors of various characteristics including heterogeneity, disease, biopsy type and age. As part of the study, we evaluated the impact these variable have on the immune gene expression signature and their role as possible assay interferents.

Methods: Studies were designed to evaluate the analytical performance of a targeted RNA-seq assay for FFPE samples from NSCLC, melanoma, RCC, HNSCC, kidney and bladder cancer. To assess degree of assay tolerance to the wide range of specimen characteristics that are inherent in tumors, samples and mixed samples of various histopathologic characteristics were included. PCA and unsupervised clustering was performed on samples with checkpoint inhibition, TCRS and TILs genes to reveal sample groups with three distinct immune signatures (low, indeterminate and high). Further correlation and over-representation analysis was performed to determine impact of specimen characteristics on these three immune signatures.

Results: Immune signatures were maintained for the majority of characteristics studied within a specified range. As expected, only TIL status was significantly associated with the high expression group. Other factors including architecture, neoplastic content, percent necrosis, stroma quality/quantity, T-Path, PMR, specimen type, tissue amount and specimen age were not over-represented in any immune signature.

Conclusion: Tumor samples harbor a mixture of potential assay interferents including variable benign, neoplastic and immune cells populations with both naïve and reactive stroma contributing to a complex tumor microenvironment that is difficult to catalogue prior to testing. Our study demonstrates that the immune signature present in the tumor microenvironment is sufficiently strong to withstand a wide range of tumor heterogeneity, thereby reducing the need of extensive tissue macrodissection and the exclusion of samples previously thought to be non-evaluable.

Citation Format: Jeffrey Conroy, Sean Glenn, Blake Burgher, Sarabjot Pabla, Maochun Qin, Jon Andreas, Vincent Giamo, Marc Ernstoff, Mary Nesline, Ji He, Mark Gardner, Carl Morrison. NGS reveals specimen characteristics have minimal impact on immune gene expression signature [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 1625. doi:10.1158/1538-7445.AM2017-1625

Abstract 1626: Technical variability in NGS immune gene expression and mutation profiling has a nominal effect on tumor classification

Background: A custom NGS cancer immune gene expression assay was developed which measures the transcript level of &gt;350 genes involved in T-cell receptor signaling (TCRS), tumor infiltrating lymphocyte (TILs) complement as well as other key targets expected to predict the likelihood of patient response to checkpoint inhibitors (CPI). In parallel to the gene expression assay, mutational profiling was carried out using the 409 gene Comprehensive Cancer Panel (ThermoFisher). As variability between runs is common when performing NGS assays a detailed comparison of specific technical variations were assessed for their ability to effect gene expression and mutation profiles of clinical FFPE samples.

Methods: Studies were designed to characterize the analytical performance of the immune response NGS assay using RNA and DNA from a subset of 300 FFPE tissues representing NSCLC, melanoma, renal cell carcinoma and bladder cancer. As part of the study, we tested the impact of variability in RNA and DNA input quantity at the library preparation step, sample batch size which affects mapped reads/sample and depth of coverage, and linearity of expression and sensitivity of mutation profiling through serial dilutions of pico-molar (pM) input of normalized library. PCA and unsupervised clustering was performed on samples with checkpoint inhibition, TCRS and TILs genes as well as mutational profiling to reveal sample groups with three distinct immune signatures (low, indeterminate and high). Further correlation and over-representation analysis was performed to determine impact of technical characteristics on these three immune signatures.

Results: Immune signatures including mutation profiles and gene expression levels were maintained throughout variable RNA/DNA input amounts at the library generation level as well as with diminution of pM levels of library pooled at the sequencing step. Increase in the number of mapped reads and sequencing depth through decreasing the number of batched samples per sequencing run also did not affect the gene expression and mutation profile signatures of the FFPE derived samples.

Conclusion: The gene expression and mutation profiles responsible for classifying FFPE samples using NGS are not affected by variation normally introduced in the technical workflow commonly associated with these platforms. The analytical assessment of input at the nucleic acid, library, and sample size level has shown the plasticity available when using amplicon based NGS technologies for classifying the immune gene expression signature as well as mutational profiles of FFPE derived clinical tumor samples. This flexibility increases the strength and utility of NGS-base gene expression profiling and mutational analysis of tumor samples for both basic research and clinical applications.

Citation Format: Sean Glenn, Jeffrey Conroy, Blake Burgher, Sarabjot Pabla, Maochun Qin, Jon Andreas, Vincent Giamo, Marc Ernstoff, Mary Nesline, Ji He, Mark Gardner, Carl Morrison. Technical variability in NGS immune gene expression and mutation profiling has a nominal effect on tumor classification [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 1626. doi:10.1158/1538-7445.AM2017-1626

ESMO / ASCO Recommendations for a Global Curriculum in Medical Oncology Edition 2016

The European Society for Medical Oncology (ESMO) and the American Society of Clinical Oncology (ASCO) are publishing a new edition of the ESMO/ASCO Global Curriculum (GC) thanks to contribution of 64 ESMO-appointed and 32 ASCO-appointed authors. First published in 2004 and updated in 2010, the GC edition 2016 answers to the need for updated recommendations for the training of physicians in medical oncology by defining the standard to be fulfilled to qualify as medical oncologists. At times of internationalisation of healthcare and increased mobility of patients and physicians, the GC aims to provide state-of-the-art cancer care to all patients wherever they live. Recent progress in the field of cancer research has indeed resulted in diagnostic and therapeutic innovations such as targeted therapies as a standard therapeutic approach or personalised cancer medicine apart from the revival of immunotherapy, requiring specialised training for medical oncology trainees. Thus, several new chapters on technical contents such as molecular pathology, translational research or molecular imaging and on conceptual attitudes towards human principles like genetic counselling or survivorship have been integrated in the GC. The GC edition 2016 consists of 12 sections with 17 subsections, 44 chapters and 35 subchapters, respectively. Besides renewal in its contents, the GC underwent a principal formal change taking into consideration modern didactic principles. It is presented in a template-based format that subcategorises the detailed outcome requirements into learning objectives, awareness, knowledge and skills. Consecutive steps will be those of harmonising and implementing teaching and assessment strategies.

Phase 3 study of docosahexaenoic acid-paclitaxel versus dacarbazine in patients with metastatic malignant melanoma

BACKGROUND

Docosahexaenoic acid-paclitaxel (DHA-paclitaxel, Taxoprexin(®)) is made by covalently conjugating the essential fatty acid DHA to the paclitaxel molecule. Preclinical studies of DHA-paclitaxel have demonstrated increased activity relative to paclitaxel and the potential for an improved therapeutic ratio. In the present study, the efficacy and toxicity profiles of DHA-paclitaxel were compared with those of dacarbazine.

METHODS

In this study, 393 chemonaive patients with metastatic melanoma were randomly assigned to receive either DHA-paclitaxel at a starting dose of 900 mg/m(2) IV on day 1 every 3 weeks or dacarbazine at a starting dose of 1000 mg/m(2) IV on day 1 every 3 weeks. The primary end point of the study was the comparison of overall survival (OS).

RESULTS

No significant difference in OS was noted between patients in the DHA-paclitaxel and dacarbazine arms. Similarly, there were no significant differences in response rate, duration of response, time to progression, and time to treatment failure between the two drugs. Safety results of the two drugs were as predicted from prior studies. Myelosuppression was more common with DHA-paclitaxel.

CONCLUSIONS

DHA-paclitaxel was not superior to dacarbazine. We conclude that further studies with the drug on an every 3-week schedule in melanoma are not warranted.

Abstract 799: Clinical correlation of variable expression of extracellular matrix metalloprotease inducer in renal cell carcinoma: Analysis of a tissue microarray using immunostaining scores

Extracellular matrix metalloprotease inducer (EMMPRIN, E) is a glycoprotein involved in cell signaling. E is thought to be involved in tumor invasiveness via tumor-stromal interactions and homophilic interactions between tumor cells. E is known to be highly expressed on the surface of malignant tumors, including RCC.

We evaluated E expression on 77 patients with renal neoplasms, including 57 clear cell (CRCC), 9 chromophobe (ChRCC), 4 papillary (PRCC) carcinomas, 3 oncocytomas (OCC), 2 CRCC with sarcomatoid differentiation (SRCC), and 2 metastatic tumors using immunohistochemistry on a tissue microarray (TMA). The TMA included two samples of each tumor and an adjacent sample of normal parenchyma from each patient. The TMA was stained with goat anti-human E antibody specific for the extracellular domain of E (R&D Systems at 1:400 dilution). E staining was graded in both cytoplasmic and membranous domains for intensity on a 0-3 scale and for % staining in deciles from 0 to 100 percent. A final staining score was obtained for cytoplasm and membranes separately by multiplying the average intensity and % cells staining for each of the two tumor samples from each patient.

Our results show a mean membranous staining score of 134 +/- 10 and cytoplasmic score of 85 +/- 8 from the tumor tissues. Normal tissues showed a mean membranous score of 22 +/- 3 with a cytoplasmic score of 160 +/- 9. CRCC showed a statistically significant lower membranous and cytoplasmic score compared to other tissue types combined (120 +/- 13 & 71 +/- 9 vs. 171 +/- 20 & 125 +/- 13; p=0.029 &0.006, respectively). TNM stage I and II tumors (n=49) also showed a significantly lower membranous and cytoplasmic score compared to stage III and IV tumors (n=28) (110 +/- 11 & 66 +/- 9 vs. 174 +/- 18 & 119 +/- 14; p= 0.004 & 0.003). Fuhrman nuclear grades I and II (n=41) showed a statistically significant lower cytoplasmic score than grades III and IV (n=35) (58 +/- 9 vs. 106 +/- 11 p=0.003). Tumor size correlated with increasing E expression when E was treated as a continuous variable (membranous p=0.002; cytoplasmic p=0.01). A lower membranous and cytoplasmic E score was also seen in patients still alive after a mean follow up time of 6.3 years compared to patients who had died from all causes of mortality (108 +/- 14 vs. 155 +/- 14 & 64+/-11 vs. 103 +/- 11; p= 0.026 and p=0.020).

In summary, in cancerous tissues, membranous expression increases as cytoplasmic expression decreases relative to normal tissues. However, increased E expression in both membranes and cytoplasm was found to correlate with increased tumor size, stage, and decreased survival amongst tumor tissues. These data support variable expression of E throughout the course of malignancy. Further investigation is needed to understand the trafficking and regulatory mechanisms that may be responsible for this variable E expression.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

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 799.

Abstract 2400: Treatment of colorectal cancer patients after resection of metastases with a tumor lysate pulsed dendritic cell vaccine: association between immune response and recurrence free survival

Introduction. Phase III trials have shown that a vaccine consisting of irradiated autologous tumor cells plus bacille Calmette-Guerin (BCG) can induce anti-tumor immune responses in patients after resection of colorectal cancer. We have demonstrated in preclinical studies that an intranodally injected tumor lysate pulsed dendritic cell (DC) vaccine induces a more potent immune response than tumor cells plus BCG. Preclinical studies also indicate that DC maturation via signaling through CD40 increases vaccine potency.

Patients and Methods. Twenty six patients who had undergone resection of colorectal metastases were treated with an intranodal injection of a vaccine consisting of autologous tumor lysate pulsed dendritic cells. Keyhole limpet hemocyanin (KLH) was added to the lysate as an adjuvant and a control protein. Patients were randomized to receive DCs that had been either activated or not activated with rhCD40L. Immune responses were evaluated with a dye dilution proliferation assay, an IFNγ ELISPOT assay and delayed type hypersensitivity (DTH) testing. All patients were followed for a minimum of 5.5 years after vaccination.

Results. The vaccine was administered to all patients with minimal toxicity. Immunization induced an autologous tumor specific proliferative T cell immune response in 8 of 24 assessable patients (33%), a tumor specific IFNγ secretory response in 10 of 24 patients (42%) and a DTH response to autologous tumor cells in 14 of 23 patients (61%). KLH specific responses were induced in 54%, 83% and 60% of patients by proliferation, IFNγ ELISPOT and DTH assays, respectively. Use of this whole cell antigen source induced peptide (CEA, Her-2 neu, Muc-1) specific T cell immune responses in half of the assayed patients.

Relapse free survival (RFS) was 58%, 41% and 37% at 1, 2 and 5 years. Patients with evidence of a vaccine induced anti-tumor proliferative T cell immune response one week after vaccination had a markedly better RFS at 5 years (67% vs 31%, p=0.057) than non-responders. There was a trend towards better RFS at 5 years (67% vs 23%, p= 0.09) in patients who developed a vaccine induced tumor specific IFNγ T cell response. No association was observed between induction of KLH specific immune responses and RFS.

DCs grown in the presence of rhCD40L were observed to have a significantly greater expression of the costimulatory molecule CD86 and the maturation marker CD83. However, rhCD40L DC activation did not significantly affect the percentage of patients with positive immune responses.

Conclusions. Adjuvant treatment of patients after resection of colorectal metastases with a tumor lysate pulsed dendritic cell vaccine induced tumor specific immune responses in a high proportion of patients. There was an association between induction of tumor specific immune responses and recurrence free survival.

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 2400.

Phase II study of recombinant IL-21 (rIL-21) plus sorafenib as second- or third-line therapy for metastatic renal cell cancer (mRCC): Final results

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Background: Despite the positive impact of targeted therapies on treatment for mRCC, the efficacy of these agents appears to decrease beyond the first-line setting. There is an unmet need for novel therapies after failure of vascular endothelial growth factor (VEGF)-directed agents. rIL-21, a cytokine that enhances CD8+ T-cell and NK cell activity, has single-agent antitumor activity (J Clin Oncol. 2008;26:2034). Based on promising results of a phase I study of rIL-21 plus sorafenib, we initiated a phase II study to explore the safety and efficacy of this combination as second- or third-line treatment for mRCC. Methods: Patients with mRCC received second- or third-line therapy with sorafenib 400 mg PO BID continuously plus rIL-21 30 μg/kg IV on days 1–5 and 15–19 of each 7-week treatment course (TC). Efficacy endpoints included progression-free survival (PFS) and overall response rate (ORR) per RECIST. Response was assessed by the investigator and by independent radiologic review (IRR). Results: 33 patients were enrolled from 14 sites in the U.S. and Canada. Median age was 61 years (range, 46–75); ECOG performance status was 0 (n=15) or 1 (n=18). Patients had received 1 (n=25) or 2 (n=8) prior lines of therapy, including sunitinib (n=19), temsirolimus (n=5), bevacizumab (n=3), everolimus (n=2), IL-2 (n=11), or other (n=4). Grade ≥3 adverse events considered at least possibly related to study drug and occurring in ≥3 patients included hypophosphatemia (33%), hand-foot syndrome (24%), rash (24%), thrombocytopenia (8%), and neutropenia (8%). Twelve patients remain on study; 13 withdrew for progressive disease (PD), 6 for toxicity, and 2 for other reasons. IRR has been performed for the first 23 patients who completed at least 1 full TC, with 6 confirmed PR (26%), 1 unconfirmed PR (4%), 14 SD (61%), and 2 PD (9%). While median PFS cannot yet be determined, 14 of the first 29 patients have completed at least 3 TCs, equivalent to approximately 21 weeks, with SD or better. Conclusions: rIL-21 plus sorafenib is associated with an acceptable safety profile and promising antitumor efficacy in previously treated patients with mRCC. The observed ORR to date compares favorably with the rate previously reported for sorafenib in the first and second-line setting.

[Table: see text]

Chemo-hormonal therapy for biochemical progression of prostate cancer

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Background: Androgen deprivation therapy (ADT) is effective for relapsed prostate cancer, but is rarely curative. The purpose of this trial was to determine the feasibility, toxicity and PSA response of chemotherapy and ADT for men with PSA relapse. Methods: Eligible men had a rising PSA and no metastases after prostatectomy and/or radiation for localized disease. Treatment consisted of four cycles of docetaxel (70 mg/M2) every 21 days and estramustine 280 mg three times daily on days 1–5. After chemotherapy, goserelin acetate and bicalutamide 50 mg daily were prescribed for 15 months. Results: Sixty-two patients were enrolled at four institutions: median age 65 (range 49–78), median PSA 3.01 ng/mL (range 0.08–47.04), 24% Gleason 8–10. A complete PSA response (CR) was defined as PSA at or below assay-specific lower limit (0.01–0.2 ng/mL). The proportion of patients with CR after chemotherapy, after ADT and at one year off ADT was 53%, 63% and 36%. Testosterone was > 100 ng/dL (median 250 ng/dL) one year off ADT in 97%. Patients with a PSA < 3.0 ng/mL had a significantly longer time to progression (p-value 0.0002). At the time of last follow-up 24/56 (43%) who are at least one year off ADT have not progressed. Median TTP is 34 months from treatment initiation (maximum 74 months free from progression). Toxicity was manageable with no toxic deaths: there were 4 thromboses on chemotherapy and 38% of cycles were associated with grade III/IV neutropenia with 5 cases of documented infections. Conclusion: Chemotherapy prior to hormone therapy was feasible for early prostate cancer relapse. Forty-three percent of men who are at least one year off ADT with recovered testosterone have not progressed. This approach is being tested in a randomized trial with investigation of predictors of response.

No significant financial relationships to disclose.

Immunomodulatory effects of high-dose and low-dose interferon alpha2b in patients with high-risk resected melanoma: the E2690 laboratory corollary of intergroup adjuvant trial E1690

BACKGROUND

The clinical antitumor activity of recombinant interferon alpha2b (IFNalpha2b) has been well documented in patients with advanced and high-risk melanoma; however, its mechanism of action remains conjectural. Trial E2690 evaluated the immunomodulatory effects of IFNalpha2b in vivo during treatment at high doses (the HDI arm; n = 51 patients) and at low doses (the LDI arm; n = 54 patients) in relation to standard observation (OBS; n = 43 patients).

METHODS

This study evaluated peripheral blood lymphocytes (PBLs) for phenotypic markers and cytotoxic functions at 1 month, 3 months, and 12 months in the HDI arm, the LDI arm, and the OBS arm and examined correlations between changes observed in PBLs or in tumors with regard to treatment dosage and disease outcome. Tumor biopsy samples were studied for response to IFNalpha2b at a range of concentrations in vitro.

RESULTS

Baseline blood phenotypic and functional assays did not predict disease outcome; however, modulation of these immunologic assays by IFNalpha2b treatment was observed and was associated with IFNalpha2b dosage. Tumor cell class II major histocompatibility antigen expression (human leukocyte/lymphocyte antigen DR) and adhesion molecule expression (ICAM-1) were modulated by exposure to IFNalpha2b in a dose dependent manner. Blood natural killer (NK) cell function, T-cell function, and subset distribution were modulated early by patients in the HDI arm and later by patients in the LDI arm. None of the variables tested in these studies predicted recurrence free survival. The numbers of patients studied were smaller than may be needed to detect potentially clinically significant changes.

CONCLUSIONS

These data demonstrate changes in immunologic parameters associated with IFNalpha2b treatment and dosage that may account for some of the differences in the clinical efficacy of this modality. The current results also suggest the need for further study of newer molecular intermediates of IFNalpha2b and T-cell response to specific antigens of melanoma.

Phase I studies with trimetrexate: clinical pharmacology, analytical methodology, and pharmacokinetics

Twenty-two patients with advanced solid tumors were treated with a quinazoline folate antagonist, trimetrexate, to determine the toxicity spectrum, the maximal tolerated dose, and the pharmacokinetics of the drug. Negligible toxicity was seen with single doses of 10-70 mg/m2 given as a 1-h infusion. Single doses of 120 mg/m2 infused over 1 h caused moderate to grade 4 toxicity in five of nine patients treated. Two patients who had no toxicity at this level were escalated to a dose of 213 mg/m2 with mild to moderate toxicity. The primary dose-limiting toxicity was myelosuppression. Moderate transaminase elevations, rash, anorexia, nausea and vomiting, and mucositis were occasionally seen. Although there was variation in dose tolerance to this drug, with selected patients able to tolerate higher doses, we consider 120 mg/m2 every 2 weeks to be the maximal tolerated dose, and the recommended Phase II starting dose. Trimetrexate plasma concentration-time curves were best described as biphasic (N = 9) or triphasic (N = 5) in form. The half-life of the terminal elimination-phase was 16.4 h. The mean residence time was 17.8 h. The volume of distribution of the plasma compartment and the volume of distribution at steady-state were 0.17 and 0.62 liter/kg, respectively. Plasma clearance was 53 ml/min. Plasma concentrations as determined by dihydrofolate reductase enzyme inhibition assay and high-performance liquid chromatography were initially identical, but diverged at later times. Divergences were seen also in urinary recovery as determined by the two methods. Both results suggest the appearance of metabolite(s) of trimetrexate which can inhibit dihydrofolate reductase. Measurable objective solid tumor responses were not seen in this Phase I study, although three patients with colon cancer had stable disease lasting 18, 26, and 26 weeks, respectively.

Potential applications of the interferons in oncology: lessons drawn from studies of human melanoma

The rationale for application of interferons in the treatment of melanoma is based on evidence suggesting that this tumor exhibits antigens capable of eliciting a host immune response. Agents that act as immunomodulators or that enhance the expression of tumor antigens may have greater therapeutic potential than agents that act solely as direct cytotoxic or antiproliferative agents. Data suggest that interferons may manifest all three categories of antineoplastic function. Early empirical trials with naturally derived leukocyte-lymphoblastoid interferons yielded poor therapeutic results. In contrast, in four subsequent trials conducted using recombinant DNA-synthesized interferon alfa 2's at three independent institutions, an objective response rate of 19% was achieved. Of the 20 responses obtained in the 102 evaluable patients, eight were complete. Three further preliminary reports enlarged the data base to 215 patients, 35 of whom showed an objective response. The response to systemic interferon alfa-2's appears to be associated with several factors including (1) continuous treatment for periods of up to several months at dosages greater than 10 MU/day intravenously (IV) or intramuscularly (IM) or 12.5 MU/m2/day IM on alternate days, and (2) metastatic tumor involving nonvisceral sites and the lung. The analysis of immunologic and other factors that may be related to or predictive of response has been hampered by the low overall frequency of response. New trials currently in progress to determine the efficacy of interferon alfa-2's as an adjuvant to surgery in candidates at high risk of recurrence and the efficacy of interferon alfa-2's when used in combination with gamma interferon, other biological agents, and chemotherapy may allow these questions to be resolved.

Melanoma: therapeutic options with recombinant interferons

Melanoma is a neoplasm of rising incidence, especially in people under 35 years of age. It is a neoplasm for which we lack effective treatments after failure of definitive surgery. The strong rationale for immunologic intervention and encouraging early results obtained with recombinant interferons in multiple trials of patients with advanced melanoma are reviewed. Criteria for evaluation of response to interferons, which ideally include a minimum treatment duration of 3 months, liken this modality to endocrine therapy of other cancers. Objective regression has been obtained in 20% of patients entered into trials of recombinant interferon alfa-2a and alpha-2b. More interestingly, the fraction of all responses with alfa-2a and alfa-2b that are complete responses is nearly one third; these complete responses have proven to be extremely durable (1 + to 3+ years) in several independent trials. Trials in progress to determine the effects of recombinant alpha interferons in the adjuvant setting of high-risk stage II (lymph node metastatic) or stage I (deep primary) melanoma are noted. The rationale and trial designs for combined trials of interferons of different types (alpha or beta plus gamma), interferons plus more tumor-specific antibodies, and interferon-chemotherapy combinations are presented. Recombinant interferons have achieved a place in the developmental armamentarium of medical oncology for melanoma--and phase III trials to compare the relative effects of decarbazine or semustine and interferon alpha are under way. The challenge now is to understand the mechanism of action for interferons, which may optimize the effects of the substance alone, and for interferon use in combination with other agents, such as antibodies, whose effects may be enhanced when used in conjunction with interferon treatment.