Subgroup analysis of patients with no prior chemotherapy in EMERALD: A phase 3 trial evaluating elacestrant, an oral selective estrogen receptor degrader (SERD), versus investigator’s choice of endocrine monotherapy for ER+/HER2-advanced/metastatic breast cancer (mBC)

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Background: EMERALD demonstrated significantly prolonged progression-free survival (PFS) and a manageable toxicity profile for elacestrant vs standard of care endocrine therapy (SOC) in patients with ER+/HER2- mBC following progression on prior endocrine and CDK4/6 inhibitor therapy. Benefit was observed in the overall study population and in patients with ESR1 mutations (mESR1). Here, we report a subgroup analysis from EMERALD in patients with no prior chemotherapy. Methods: EMERALD (NCT03778931) is a randomized, open-label, phase 3 trial that enrolled patients with ER+/HER2− mBC who had 1–2 lines of endocrine therapy, mandatory pretreatment with a CDK4/6 inhibitor, and ≤1 chemotherapy. Patients were randomized 1:1 to elacestrant (400 mg orally daily) or SOC (investigator’s choice of fulvestrant or aromatase inhibitor). Primary endpoints were PFS in all patients and patients with mESR1. In this analysis, we compared PFS between elacestrant and SOC in patients without prior chemotherapy. Results: Among the 477 patients enrolled in the trial, 77.8% (n = 371) had not received prior chemotherapy for mBC (median age = 64). Among patients without prior chemotherapy, treatment with elacestrant was associated with significantly prolonged PFS compared to SOC in both the overall population (hazard ratio [HR] = 0.68 [95% CI, 0.52-0.89] P = 0.004; median PFS 3.7 vs 2.0; 6-mo PFS 38% vs 23%; 12-mo PFS 27% vs 12%), and patients with mESR1 (HR = 0.54 [95% CI, 0.36-0.80] P = 0.002; median PFS 5.3 vs 1.9; 6-mo PFS 44% vs 24%; 12-mo PFS 31% vs 12%). Key treatment-related adverse events (AEs) in the no prior chemotherapy elacestrant group were nausea (25.9%), fatigue (12.7%), and hot flush (11.1%). There were no treatment-related deaths in either group. Conclusions: Among patients with ER+/HER2− mBC without prior chemotherapy, elacestrant significantly prolonged PFS compared to SOC endocrine therapy and showed favorable outcomes in this subgroup. Clinical trial information: NCT03778931.

Abstract OT2-09-01: Phase I/II study of stereotactic radiation and abemaciclib in the management of hormone receptor positive HER2 negative breast cancer brain metastases

Background: Breast cancer patients with brain metastases have a high unmet clinical need and improved management strategies are needed. There has been interest in studying CDK 4/6 inhibitors in the management of breast cancer brain metastases. A phase II study has shown abemaciclib to have activity in the management of hormone receptor (HR)+/HER2- brain metastases. Pre-clinical data suggests a potential synergy with CDK inhibitors and radiation therapy. Stereotactic radiosurgery (SRS) is a cornerstone in the management of limited brain metastases. We hypothesize treatment with abemaciclib and SRS will be safe and improve intracranial progression free survival (PFS) compared to abemaciclib alone. Trial Design: The study is designed as a prospective, single-arm, nonrandomized, open-label, phase I/II trial of abemaciclib and endocrine therapy with SRS among patients with HR+/HER2- metastatic breast cancer brain metastases. Treatment will be initiated with one week of abemaciclib followed by stereotactic radiation to sites of brain metastases or post-operative cavities with continued abemaciclib. Safety will be monitored initially by a 3+3 design. If unexpected neurologic toxicities are noted, the dose of radiation therapy will be reduced. This will be followed by a phase II study to evaluate intracranial PFS. Eligibility: Eligible patients include those that are HR+/HER2-, ≥18, ECOG ≤2 with ≤15 breast cancer brain metastases with measurable disease per Response Assessment in Neuro-Oncology Brain Metastases (RANO-BM) criteria. Specific Aims: The primary objective of the phase I study is to evaluate the safety and feasibility of abemaciclib and SRS to sites of brain metastases in the management of HR+/HER2- metastatic breast cancer with brain metastases. The primary objective of the phase II portion is to determine PFS intracranially. Secondary objectives include evaluation of extracranial PFS, local and distant intracranial control, and overall survival. Statistical Methods: Safety and feasibility will be monitored in the phase I study using a 3 + 3 design followed by a phase II study to assess intracranial PFS. The phase II study is designed as a single-arm, two-stage trial using the Restricted-Kwak-and-Jung’s method. In the first stage, a total of 21 patients will be enrolled. If pre-specified endpoints are met, an additional 10 patients will be enrolled in the second stage. Patient Accrual: A total of up to 31 patients will be enrolled inclusive of patients in the phase I portion treated at the recommended phase II dose. Clinical trial information: NCT04923542.

Citation Format: Kamran A. Ahmed, Youngchul Kim, Michelle DeJesus, Sasha J. Beyer, Nicole O. Williams, Joshua Palmer, Kristina D. Woodhouse, Rashmi K. Murthy, Jing Li, Avan J. Armaghani, John A. Arrington, Ricardo L. Costa, Brian J. Czerniecki, Arnold B. Etame, Peter A. Forsyth, Hung T. Khong, Daniel E. Oliver, Marilin Rosa, Solmaz Sahebjam, Hatem H. Soliman, Aixa E. Soyano, Michael A. Vogelbaum, Michael Yu, Hyo S. Han. Phase I/II study of stereotactic radiation and abemaciclib in the management of hormone receptor positive HER2 negative breast cancer brain metastases [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr OT2-09-01.

Fatal Allograft Rejection and Cardiac Allograft Vasculopathy After Treatment With Pembrolizumab for Metastatic Melanoma in a Heart Transplant Recipient: A Case Report

Checkpoint inhibitors decrease the progression of many cancers. However, the experience in immunosuppressed patients is limited, with reports of possible serious adverse events. We present a heart transplant recipient treated with pembrolizumab for metastatic melanoma who developed fatal rejection. The patient was a 29 year-old man who underwent heart transplantation at the age of 10 years for congenital heart disease. Seventeen years after transplant, he was diagnosed with scalp melanoma pT3a, N2a, M0, Stage IIIA, positive for BRAF V600E mutation treated with excision, which metastasized to his lungs and brain a year later. Dabrafenib and trametinib were started with transient response. Additional options and their risks were discussed, and pembrolizumab was started 4 months later due to the incomplete response to previous therapy. Five days after initiation the patient presented with moderate cellular rejection and possible antibody mediated rejection (ISHLT Grade 2R, pAMR 1H). Pembrolizumab was discontinued, and he was treated with steroids. Seven months later he presented in cardiogenic shock and severe coronary allograft vasculopathy. Biopsy was negative for cellular rejection, but suspicious for antibody mediated rejection (ISHLT Grade 0R, pAMR 1H), and he had a new serum alloantibody. Despite steroids and plasmapheresis he remained in refractory cardiogenic shock and died of cardiac arrest.

Real-world benefit of combination palbociclib and endocrine therapy for metastatic breast cancer and correlation with neutropenia

BACKGROUND

Combination CDK4/6 inhibitor and endocrine therapy has been shown to significantly improve progression-free survival (PFS) in patients with hormone receptor (HR)-positive, HER2-negative metastatic breast cancer (mBC). The aim of this retrospective study was to evaluate the real-world benefit of first-line combination therapy in this cohort and to correlate treatment efficacy with neutropenia, a common toxicity of CDK4/6 inhibitors.

METHODS

This study included HR-positive, HER2-negative advanced or mBC patients who were treated with palbociclib plus endocrine therapy, mainly letrozole, between 1 January 2015 and 1 March 2018. Progression-free survival (PFS) was determined using Kaplan-Meier analysis. The predictive value of absolute neutrophil count (ANC) and neutrophil-to-lymphocyte ratio (NLR) for PFS were explored using Cox regression models. Both ANC and NLR were used as a time-dependent variable.

RESULTS

In total, 165 patients were included with median PFS of 24.19 months (95% CI 18.93-NR). Median PFS for patients with bone-only metastases (n = 54) was not reached (95% CI 18.21-NR). Among patients with all other metastases (n = 111), median PFS was 24.19 months (95% CI 16.33-33.82). Lower ANC was correlated with decreased risk of progression (HR 0.84, 95% CI 0.71-0.97, p = 0.008). There was no significant association between NLR and the risk of disease progression (HR 1.07, 95% CI 0.97-1.18, p = 0.203).

CONCLUSION

The effectiveness of palbociclib and endocrine therapy in the treatment of HR-positive, HER2-negative mBC in the real-world setting is similar to the efficacy reported in the PALOMA-2 trial. Patients with lower neutrophil count may have a lower risk of early disease progression.

Nivolumab and Stereotactic Radiosurgery for Patients With Breast Cancer Brain Metastases: A Nonrandomized, Open-Label Phase 1b Study

Purpose

Methods and Materials

Results

Conclusions

Retrospective cohort study of estrogen receptor low positive early breast cancer using real world data

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Background: Estrogen receptor (ER) positive breast cancer (BC) is a heterogeneous disease, with ongoing debate on the optimal cut off point for clinically relevant ER expression. Tumors harboring ≤10% ER expression are associated with poor outcomes. We used a real-world database to assess prognostic and predictive value of an alternative ER expression cut points. Methods: This retrospective cohort study used the nationwide Flatiron Health electronic health record (EHR)-derived de-identified database. During the study period, the de-identified data originated from approximately 280 US cancer clinics (̃800 sites of care). We evaluated the association between ER expression (assessed locally by immunohistochemistry according to ASCO/CAP guidelines) with tumor characteristics, and treatment patterns of patients with early-stage BC (stage I-III) using descriptive statistics. Recurrence free survival and overall survival was defined as time in months from date of surgery until the data of documented cancer recurrence or death respectively. We used Kaplan Myer survival curves to calculate recurrence free (RFS) and overall survival (OS) of patients with ER low, ER intermediate and ER high tumors. To define an alternative ER expression cut point, the data set was divided into 2/3 training and 1/3 test data. A cut point analysis was performed on the training data set to find the optimum cut point of ER+ staining based on correlation with recurrence free survival as the outcome. Results: Among 4,697 ER positive early-stage BC patients, 83 (1.8%) had ER low (ER expression :1-10%) and 36 (0.8%) had ER intermediate BC (11-20%). Median follow up time was 63 months (range 24-84). ER low tumors were associated with higher tumor grade, larger size, and higher axillary tumor burden compared to ER high positive tumors ( > 20% ER expression). African American patients had a higher prevalence of both triple negative and ER low positive BCs compared to ER high tumors- 21%, 22%, and 8% respectively. No significant differences in patient- or tumor-associated characteristics were observed between Low ER and intermediate-ER positive BC patients. Both ER low and intermediate positive tumor patients had survival outcomes similar to patients with TNBC and worse than ER high positive tumors (p < 0.001). No significant correlations between endocrine therapy and RFS or OS were observed among patients with either ER low or intermediate BCs (HR 1.47 and 2.57, p > 0.05; respectively). Sensitivity analysis showed that tumors with ≤ 20% ER expression were associated with worse RFS in both univariate and multivariate analyses (p < 0.05). Conclusions: These findings suggest that patients with ER expression rates ≤ 20% have poor outcomes and derive minimal benefit from endocrine therapies.

Nivolumab and stereotactic radiosurgery for patients with breast cancer brain metastases: A non-randomized, open-label phase Ib study

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Background: There may be a potential synergy intracranially between stereotactic radiation and immune checkpoint inhibition in brain metastases management. We hypothesize treatment with nivolumab and stereotactic radiosurgery (SRS) will be feasible and well tolerated and may improve intracranial tumor control rates compared to SRS alone in the management of breast cancer brain metastases. Methods: The study was designed as a prospective, single-arm, nonrandomized, open-label, phase Ib trial of nivolumab and SRS among patients with metastatic breast cancer brain metastases. Key eligibility criteria included patients with breast cancer brain metastases of all subtypes, age ≥ 18, ECOG ≤ 2 with ≤ 10 brain metastases. The primary objective was to evaluate the safety and feasibility of study therapy. Secondary objectives included evaluation of local brain metastasis control, distant brain metastasis control, progression free survival (PFS), and overall survival following study therapy. Response Assessment in Neuro-Oncology Brain Metastases (RANO-BM) and immune-related Response Evaluation Criteria in Solid Tumors (irRECIST) criteria were used to assess intracranial and extracranial disease, respectively. Treatment was initiated with a dose of nivolumab (480 mg IV) that was repeated every 4 weeks. The initial dose of nivolumab was followed 1 week later by SRS. This study is closed to accrual and is registered with ClinicalTrials.gov, NCT03807765. Results: Between February 2019 and July 2020, a total of 12 patients were treated to 17 lesions. Median follow-up from start of protocol therapy is currently 9.6 months (range: 2.8-18.7 months). No dose limiting toxicities (DLTs) were noted in our patient population. The most common neurologic adverse events included grade 1-2 headaches and dizziness occurring in 5 (42%) of patients. Median intracranial control was 6.2 months (95% CI 3.0 -14) with 6 and 12 month control rates of 55% and 22%, respectively. A total of 4 patients had systemic progression during the study. Median time to systemic PFS has not been reached with 6 and 12 month rates of 63% and 51%, respectively. Conclusions: Nivolumab and SRS is a safe and feasible treatment option in breast cancer brain metastases. Preliminary studies reveal activity in certain breast cancer patients to study therapy. Clinical trial information: NCT03807765.

A phase 2 trial of talimogene laherparepvec (TVEC) in combination with neoadjuvant chemotherapy for the treatment of nonmetastatic triple-negative breast cancer

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Background: TVEC is a modified oncolytic herpes simplex 1 (HSV1) virus currently FDA approved for the treatment of unresectable cutaneous and nodal melanoma. TVEC is designed to preferentially lyse tumor cells over normal tissue to release tumor associated antigens, produces GM-CSF to activate dendritic cells, and stimulates T cells to infiltrate the tumor (TILs). TILs in breast cancer are associated with better response to neoadjuvant chemotherapy (NAC), so we hypothesized that intratumoral TVEC may enhance response to NAC. We report results of a phase 2 trial combining NAC with TVEC in stage 2-3 TNBC. Methods: Stage II-III TNBC pts (N = 37) were to be enrolled into a single arm, optimal Simon 2 stage phase 2 trial with TVEC (10^6 PFU 1st dose then 10^8 PFU x 4 doses) weeks 1,4,6,8,10 + weekly paclitaxel (80mg/m2) IV x 12, followed by dose dense AC (doxorubicin/cyclophosphamide 60/600 mg/m2) IV q2weeks x 4 alone given preoperatively. Primary endpoint was residual cancer burden 0 rate (RCB0). Trial meets primary endpoint with ≥15 RCB0 responses out of 37 evaluable pts, assuming p1 = 45% vs. p0 = 30% with one sided type I error rate at 0.10 and power at 70%. Results: Forty pts were enrolled at Moffitt (5/2018 – 4/2020) and evaluable for safety with 3 pts non-evaluable for efficacy due to incomplete treatment. Study demographics: median age 49 (27-66), 67.5% White, 10% Black, 15% Hispanic, clinical stage II 83% and III 17%, node + 42%. The RCB0 rate = 16/37 (43%, 95% CI 27-61%) and additional 9 pts with RCB-1 (RCB0/1 rate 68%, 95% CI 50-82%). Toxicities did not differ significantly from expected NAC toxicities except for increased brief G1-2 fevers, chills, injection site pains. Four pts had G2-3 thromboembolic events (10%) slightly greater than expected 6% rate on NAC. Conclusions: Addition of TVEC to NAC increased RCB0 rates with manageable toxicities and warrants additional investigation in TNBC. Immune correlates and updated survival data will be presented at the meeting. Clinical trial information: NCT02779855.

The Immune Checkpoint Kick Start: Optimization of Neoadjuvant Combination Therapy Using Game Theory

PURPOSE

In an upcoming clinical trial at the Moffitt Cancer Center for women with stage 2/3 estrogen receptor-positive breast cancer, treatment with an aromatase inhibitor and a PD-L1 checkpoint inhibitor combination will be investigated to lower a preoperative endocrine prognostic index (PEPI) that correlates with relapse-free survival. PEPI is fundamentally a static index, measured at the end of neoadjuvant therapy before surgery. We have developed a mathematical model of the essential components of the PEPI score to identify successful combination therapy regimens that minimize tumor burden and metastatic potential, on the basis of time-dependent trade-offs in the system.

METHODS

We considered two molecular traits, CCR7 and PD-L1, which correlate with treatment response and increased metastatic risk. We used a matrix game model with the four phenotypic strategies to examine the frequency-dependent interactions of cancer cells. This game was embedded in an ecological model of tumor population-growth dynamics. The resulting model predicts evolutionary and ecological dynamics that track with changes in the PEPI score.

RESULTS

We considered various treatment regimens on the basis of combinations of the two therapies with drug holidays. By considering the trade off between tumor burden and metastatic potential, the optimal therapy plan was a 1-month kick start of the immune checkpoint inhibitor followed by 5 months of continuous combination therapy. Relative to a protocol giving both therapeutics together from the start, this delayed regimen resulted in transient suboptimal tumor regression while maintaining a phenotypic constitution that is more amenable to fast tumor regression for the final 5 months of therapy.

CONCLUSION

The mathematical model provides a useful abstraction of clinical intuition, enabling hypothesis generation and testing of clinical assumptions.

Abstract OT3-10-01: Phase Ib study of stereotactic radiation and nivolumab in the management of metastatic breast cancer with brain metastases

Background:Patients with breast cancer brain metastases represent a poor prognosis cohort with a high unmet clinical need. Standard-of-care treatments for patients with breast cancer brain metastases include local treatments, such as surgical resection and radiation treatment modalities that include stereotactic radiosurgery (SRS) or whole brain radiotherapy. Numerous pre-clinical studies have provided evidence to combine radiation therapy with immune checkpoint inhibition to improve response rates. The evidence is strongest for short course, hypofractionated radiation regimens. We hypothesize treatment with nivolumab and SRS will be feasible and well tolerated and may improve intracranial tumor control rates compared to SRS alone. Trial Design:The study is designed as a prospective, single-arm, nonrandomized, open-label, phase Ib trial of nivolumab and SRS among patients with metastatic breast cancer brain metastases. Treatment will be initiated with a dose of nivolumab (480 mg IV) that will be repeated every 4 weeks. The initial dose of nivolumab will be followed 1 week later by SRS at sites of brain metastases or post-operative cavities. Patients will be allowed to continue endocrine and HER2-targeted therapies if brain metastases progression was noted on these agents.Eligibility:Eligible patients include those ≥18, ECOG ≤2 with ≤10 breast cancer brain metastases of all subtypes eligible for stereotactic radiation. Specific Aims:The primary objective is to evaluate the safety and feasibility of nivolumab and SRS to sites of brain metastases. Secondary objectives include evaluation of intracranial progression free survival (PFS), extracranial PFS, overall survival, local control, and distant brain control. Correlative aims include assessing blood and tissue biomarkers (i.e. PD-L1, mutation burden, TCR repertoire etc.) for association with clinical benefit.Statistical Methods:Safety and feasibility will be monitored by a 3 + 3 design followed by a dose expansion phase. Patient Accrual:This study is open with 4 patients enrolled at the time of submission. A total of 12 patients will be enrolled.Contact Information:Kamran A. Ahmed MD, Moffitt Cancer Center, email: kamran.ahmed@moffitt.org, Clinical trial information: NCT03807765.

Citation Format: Kamran A Ahmed, Youngchul Kim, Avan J. Armaghani, John A. Arrington, Jimmy J. Caudell, Ricardo L. Costa, Brian J. Czerniecki, Arnold B. Etame, Peter A. Forsyth, Hung T. Khong, Sungjune Kim, Loretta Loftus, Timothy J. Robinson, Marilin Rosa, Solmaz Sahebjam, Hatem H. Soliman, Aixa E. Soyano, Nam D. Tran, H. Michael Yu, Hyo S. Han. Phase Ib study of stereotactic radiation and nivolumab in the management of metastatic breast cancer with brain metastases [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr OT3-10-01.

Abstract P2-17-03: Real-world benefit of CDK4/6 inhibitor and endocrine therapy combination in metastatic breast cancer and correlation with neutropenia

Background: Combination of a CDK4/6 inhibitor plus endocrine therapy has been shown to significantly improve the progression free survival (PFS) in patients with hormone-receptor (HR)+, HER2- metastatic breast cancer. The aims of this retrospective study was: 1) to evaluate the real-world benefit of palbociclib plus endocrine therapy as the first line treatment in HR+, HER2- metastatic breast cancer (mBC) and 2) to correlate efficacy of the combination with neutropenia (which is a common toxicity of CDK4/6 inhibitors). Methods: This study included HR+, HER2- advanced mBC patients who were treated with palbociclib plus an endocrine therapy (mainly letrozole) at Moffitt Cancer Center between January 1, 2015 and March 1, 2018. The PFS was determined using Kaplan-Meier analysis. The predictive value of absolute neutrophil count (ANC) and neutrophil-to-lymphocyte ratio (NLR) for PFS were investigated using the univariable and multivariable Cox models. Results: A total of 165 patients were included in this retrospective cohort study. The median PFS of the full cohort was 24.19 months (95% CI 18.93 to not reached). For patients with bone metastasis only (n = 54), the median PFS was not reached (95% CI 18.21 to not reached). For patients with non-bone-only metastasis (n = 111), the median PFS was 24.19 months (95% CI 16.33 to 33.82). Patients with higher absolute neutrophil counts (ANC) are at high risk of disease progression (HR 1.15; 95% CI 1.03 to 1.29, p = 0.013). We did not find a significant association between the value of NLR and the risk of disease progression (HR 1.07 95% 0.97 to 1.18, p = 0.203). Both ANC and NLR were used as a time dependent variable. Conclusion:The effectiveness of palbociclib plus letrozole in the treatment of HR+, HER2- metastatic breast cancer in the real-world setting was found to be similar to the results from the PALOMA-2 trial. In addition, patients with a higher ANC were found to have a higher risk for early disease progression. This has implication for clinical practice [i.e., frequent dose delay and/or dose reduction based on ANC threshold of 1000/uL may not be an optimal approach. Since infection is rare, it is reasonable to reduce this threshold to a lower level such as 750-800/uL].

Citation Format: Dakota Jenneman, Xiaojun Zhong, Junjie Ma, Weihong Sun, Heather Han, Hatem Soliman, Loretta Loftus, Ricardo Costa, Avan Armaghani, Aixa Soyano, Brian Czerniecki, M. Catherine Lee, John Kiluk, Nazanin Khakpour, Susan Hoover, Christine Laronga, Hung T Khong. Real-world benefit of CDK4/6 inhibitor and endocrine therapy combination in metastatic breast cancer and correlation with neutropenia [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-17-03.

Efficacy of abemaciclib (abema) after palbociclib (palbo) in patients (pts) with metastatic breast cancer (MBC)

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Background: CDK 4/6 inhibitors (Abema and Palbo) have shown efficacy in patients with HR+/HER2- MBC. Abema is distinct from other CDK 4/6 inhibitors and was approved after the approval of Palbo. There is limited data on sequential use or cross resistance. The aim of this study was to analyze the response to Abema based therapy in MBC pts with prior exposure to Palbo. Methods: We queried our EMR database for pts who received Abema from 9/2017-9/2018 after having received prior Palbo. Under IRB approved protocol we retrospectively collected demographics, tumor characteristics, disease status, toxicities and survival. Results: 23 female pts were identified. Four patients discontinued Palbo due to toxicities: two of them remained on Abema for 8 months and the other 2 discontinued Abema due to toxicities. The remaining 19 pts (median age 57 years, range 39-76) received a mean of 5.6 prior therapies (range (1-11) including Palbo in combination with endocrine therapy (fulvestrant 9 in pts and Aromatase inhibitors (AI) in 10 pts) at the time of Abema based therapy. 73.6% had visceral involvement including brain metastasis in 26%. The median progression-free survival (PFS) of Palbo in combination with endocrine therapy was 8 months (range 2.3-14.3). Abema was given in combination with endocrine therapy in 15 pts (9 pts fulvestrant and 6 pts AI) and 4 pts received it as a single agent. The median PFS of Abema based therapy was 7.0 months (range 1.8-12.1). Four pts (21%) had a longer PFS on Abema compared to prior Palbo PFS (table). Abema was discontinued due to toxicities in 15.7%. No partial or complete response was observed but 33% had stable disease. Conclusions: Abema showed response in a significant number of pts previously exposed to Palbo and heavily treated with multiple lines of chemotherapy for widespread metastatic disease. Prospective studies are warranted to better assess the response to Abema after exposure to CDK4/6 inhibitors. [Table: see text]

Rigor prophylaxis in stage IV melanoma and renal cell carcinoma patients treated with high dose IL-2

BACKGROUND

Rigors are a significant adverse event during interleukin-2 (IL2) therapy for metastatic melanoma and renal cell carcinoma. Meperidine has been a mainstay for rigor prophylaxis but there is a paucity of data regarding possible alternatives.

METHODS

Ninety one patients receiving IL2 therapy for metastatic renal cell carcinoma and melanoma at Huntsman Cancer institute (HCI), Utah from May 2009 to October 2016 were retrospectively evaluated for rigor prophylaxis. Forty two patients received meperidine and 49 received tramadol. Rigors were tabulated using the proxy of number of doses of as needed (PRN) rigor medications and normalized by IL2 doses. Other outcomes of fever, hypotension, and renal insufficiency were noted on a binary scale and normalized by cycles. Statistical analysis was performed utilizing univariate and multivariate negative binomial models.

RESULTS

Ninety one patients were identified with metastatic melanoma or RCC who received high dose IL2 therapy. Forty two received meperidine and 49 received tramadol prophylaxis for rigors. Univariate negative binomial analysis shows incidence rate ratios (IRR): fever 0.41 (95% CI 0.28-0.62, p-value < 0.001), hypotension 1.7 (95% CI 1.11-2.61, p-value 0.015), renal insufficiency 0.58 (95% CI 0.35-0.98, p-value 0.041), rigors per all PRN meds 1.01 (95% CI 0.79-1.28, p-value 0.964), and rigors via opioid PRN meds 0.85 (95% CI 0.67-1.07, p-value 0.168). Multivariate negative binomial analysis shows IRR: fever 0.59 (95% CI 0.28-1.24, p-value 0.163), hypotension 0.93 (95% CI 0.43-2.03, p-value 0.864), renal insufficiency 1.1 (95% CI 0.52-2.32, p-value 0.807), rigors per al PRN meds 0.92 (95% CI 0.67-1.26, p-value 0.604), and rigors via opioid PRN 0.9 (95% CI 0.65-1.26, p-value 0.554).

CONCLUSION

Univariate models indicated meperidine pre-treatment was associated with significantly lower rates of fever and renal insufficiency whereas tramadol was associated with significantly lower rate of hypotension. However, when controlled for demographics and other treatment differences, these differences were no longer significant.

miR-125b regulates differentiation and metabolic reprogramming of T cell acute lymphoblastic leukemia by directly targeting A20

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematopoietic malignancy. Although it has been reported that overexpression of miR-125b leads to T-ALL development, the underlying mechanisms of miR-125b action are still unclear. The goal of this study is to delineate the role of miR-125b in T-ALL development. We found that miR-125b is highly expressed in undifferentiated leukemic T cells (CD4-negative) while its expression is low in differentiated T cells (CD4-positive). Overexpression of miR-125b increased the CD4-negative population in T cells, whereas depletion of miR-125b by miR-125b-sponge decreased the CD4-negative cell population. We identified that A20 (TNFAIP3) is a direct target of miR-125b in T cells. Overexpression of miR-125b also increased glucose uptake and oxygen consumption in T cells through targeting A20. Furthermore, restoration of A20 in miR-125b-overexpressing cells decreased the CD4-negative population in T cell leukemia, and decreased glucose uptake and oxygen consumption to the basal level of T cells transfected with vector. In conclusion, our data demonstrate that miR-125b regulates differentiation and reprogramming of T cell glucose metabolism via targeting A20. Since both de-differentiation and dysregulated glucose metabolism contribute to the development of T-cell leukemia, these findings provide novel insights into the understanding and treatment of T-ALL.

A phase I study of intratumoral ipilimumab and interleukin-2 in patients with advanced melanoma

Purpose

Intratumoral interleukin-2 (IL-2) is effective but does not generate systemic immunity. Intravenous ipilimumab produces durable clinical response in a minority of patients, with potentially severe toxicities. Circulating anti-tumor T cells activated by ipilimumab may differ greatly from tumor-infiltrating lymphocytes activated by intratumoral ipilimumab in phenotypes and functionality. The objective of this study was to primarily assess the safety of intratumoral ipilimumab/IL-2 combination and to obtain data on clinical efficacy.

Results

There was no dose limiting toxicity. While local response of injected lesions was observed in 67% patients (95% CI, 40%-93%), an abscopal response was seen in 89% (95% CI, 68%-100%). The overall response rate and clinical benefit rate by immune-related response criteria (irRC) was 40% (95% CI, 10%-70%) and 50% (95% CI, 19%-81%), respectively. Enhanced systemic immune response was observed in most patients and correlated with clinical responses.

Experimental Design

Twelve patients with unresectable stages III/IV melanoma were enrolled. A standard 3+3 design was employed to assess highest tolerable intratumoral dose of ipilimumab and IL-2 based on toxicity during the first three weeks. Escalated doses of ipilimumab was injected into only one lesion weekly for eight weeks in cohorts of three patients. A fixed dose of IL-2 was injected three times a week into the same lesion for two weeks, followed by two times a week for six weeks.

Conclusions

Intratumoral injection with the combination of ipilimumab/IL-2 is well tolerated and generates responses in both injected and non-injected lesions in the majority of patients.

Phase (Ph) 2 stage 1 clinical activity of seviteronel, a selective CYP17-lyase and androgen receptor (AR) inhibitor, in women with advanced AR+ triple-negative breast cancer (TNBC) or estrogen receptor (ER)+ BC: CLARITY-01

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Background: Seviteronel (Sevi), an oral selective CYP17-lyase and AR inhibitor that blocks testosterone and estradiol production and competitively antagonizes the AR, is in Ph 2 clinical development for BC and prostate cancer. The primary objective of this ongoing Ph 2 study (NCT02580448) is to estimate the activity of once daily Sevi in women with AR+ TNBC and ER+ BC as measured by clinical benefit rate (CBR) at 16 and 24 weeks (wk), respectively. Methods: Patients (pts) with ER+/HER2-normal metastatic BC following progression of ≥1 prior line of endocrine therapy or TNBC were enrolled with no limit of prior therapies in either cohort. Evaluable pts had AR ≥10% via central IHC staining (TNBC only) and 1 post-baseline scan. Sevi was administered at 450 mg oral daily. Scans were performed every 8 wk. Circulating tumor cell (CTC) enumeration was performed by EPIC CTC analysis. A Simon’s 2-stage design was employed to determine activity (≥2 of 13 CBR16 in TNBC and ≥2 of 12 CBR24 in ER+ BC allow for accrual to Stage 2). Results: As of 4 Oct, 2016, 16 pts with AR+ TNBC (6 evaluable) and 14 pts with ER+ BC (11 evaluable) were enrolled. 67% had visceral metastases; 10% had stable brain metastases. 60% had ≥2 lines of prior therapy for advanced disease. 13 of 14 (93%) TNBC pts who underwent central AR testing had AR ≥10%. Four pts in the TNBC cohort and 8 pts in the ER+ cohort remain on therapy. CBR16 (TNBC) and CBR24 (ER+) was 2 of 6 (33%) and 2 of 11 (18%) allowing Stage 2 accrual in both cohorts. 7 of 10 evaluable pts with CTCs present at baseline had a CTC decline at C2D1, including all that met CBR (-94.3% [-27.5, -100] median [range]). The most common adverse events (≥ 25%) were fatigue (50%), nausea (43%) and decreased appetite (33%); all Grade 1/2. Updated CBR data will be presented at the time of presentation. Conclusions: Sevi Stage 1 activity is suggested by CBRs, along with associated CTC declines in heavily pre-treated pts with high disease burden. The observed safety profile is consistent with on-target pharmacology. Stage 2 enrollment is ongoing. Sevi may provide a novel treatment option for women with AR+ TNBC or ER+ BC. Clinical trial information: NCT02580448.

Final results of a phase II multicenter trial of HF10, a replication-competent HSV-1 oncolytic virus, and ipilimumab combination treatment in patients with stage IIIB-IV unresectable or metastatic melanoma

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Background: HF10 is a bioselected replication-competent oncolytic virus derived from HSV-1. Herein, we report the safety and efficacy data of HF10 + ipilimumab (ipi) combination treatment in a Phase II trial in melanoma. Methods: Key entry criteria: age ≥ 18 yrs, ECOG ≤ 2, Stage IIIB, IIIC, or IV unresectable melanoma, ipi naïve (IV administration) and measurable non-visceral lesion(s) suitable for injection. HF10 injected into single or multiple tumors (1 x 107 TCID50/mL/dose, up to 5mL depending on tumor size and number); 4 injections q1wk; then up to 15 injections q3wk. Four ipi IV infusions (3 mg/kg; concurrent with HF10) were administered q3wk. AEs assessed per CTCAE 4.0. Tumor responses were assessed per mWHO and irRC at 12, 18, 24, 36 and 48 wks for patients (pts) continuing on HF10 monotherapy. Primary endpoint was Best Overall Response Rate (BORR) at 24 wks. Dose limiting toxicity (DLT) defined as ≥ G3 non-hematologic/hematologic toxicity, ≥ G2 neurologic toxicity, or allergic event occurring within 1st 3wks of therapy. Results: Of 46 pts enrolled and treated: 59% men, median age 67 yrs (range 28 to 91); disease stage 20% IIIB, 43% IIIC and 37% IV; 57% were treatment naïve and 43% with ≥ 1 prior cancer therapy for unresectable/metastatic melanoma. Most HF10-related AEs were ≤G2, similar to HF10 monotherapy. No DLTs were reported. 37% had ≥G3 AEs, the majority due to ipi. HF10-related ≥G3 AEs (n=3) were embolism, lymphedema, diarrhea, hypoglycemia, and groin pain. Of the 44 efficacy evaluable pts per irRC, BORR at 24 weeks was 41% (16% irCR and 25% irPR); disease stability rate was 68% (16% irCR, 25% irPR and 27% irSD). As of Feb 06, 2017, median PFS was 19 months and median overall survival was 21.8 months. Conclusions: The combination HF10 and ipilimumab treatment demonstrated a favorable benefit/risk profile and encouraging antitumor activity in pts with stage IIIB, IIIC, or IV unresectable or metastatic melanoma. Clinical trial information: NCT02272855.

A phase I trial of azacitidine and nanoparticle albumin bound paclitaxel in patients with advanced or metastatic solid tumors

Background

Secreted protein acidic and rich in cysteine (SPARC), an albumin-binding protein, is downregulated by hypermethylation in many cancers. Hypomethylating agents such as azacitidine can upregulate SPARC in tumors, which may enhance the accumulation of albumin-bound drugs at tumor site. The objectives of this phase I trial was to determine the safety and maximum tolerated dose and to assess any clinical activity of the combination of azacytidine and weekly nanoparticle-albumin-bound (nab®) paclitaxel.

Methods

Patients received escalating azacytidine doses daily for 5 days, followed by nab-paclitaxel at the standard 100mg/m2 weekly dose for 3 weeks in 4-week cycles. Dose-limiting toxicities (DLTs) were monitored during the first cycle. Serum was obtained at baseline, during and after treatment for correlative study.

Results

All sixteen total patients enrolled were evaluable for toxicity, while 13 patients were evaluable for response. Two of five patients treated with 100mg/m2 of azacytidine had DLT of prolonged grade 4 neutropenia. Therefore, the MTD of azacitidine in this regimen is 75 mg/m². Three additional patients were treated with no grade 4 toxicity in cycle 1. Clinical activity included 1 complete response (CR) in refractory DLBCL, 2 CR in ovarian cancer, 4 partial responses (PR) in ovarian and endometrial cancer, 4 stable diseases (SD) in lung, sarcoma and pancreatic cancer, 1 unconfirmed PR in breast cancer, and 1 progression of disease in CLL/SLL.

Conclusions

Priming with azacitidine 75 mg/m² daily for 5 days, followed by weekly nab-paclitaxel 100 mg/m² weekly was well tolerated and results in dramatic responses pre-treated cancer patients.

Complete response to azacitidine priming and nab-paclitaxel in non-Hodgkin lymphoma resistant to biochemotherapy

The standard of care for first-line therapy in diffuse large B-cell lymphoma (DLBCL) is the rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) regimen. For patients who fail to respond, have an incomplete response or relapse, numerous effective options exists besides salvage cisplatin-based regimen and autologous stem cell therapy. Even with this approach, the outcome remains very poor for this group of patients. The present case illustrates a 55-year-old woman diagnosed with DLBCL, who experienced an early incomplete response, later progression during treatment with the R-CHOP regimen. The patient received salvage therapy with rituximab, cisplatin and gemcitabine, again with an incomplete response. The patient declined consideration for stem cell therapy. Her disease progressed and she enrolled in the present phase I trial using azacitadine priming and nanoalbumin-bound (nab)-paclitaxel. After three cycles, follow-up positron emission tomography/computed tomography revealed a complete response for the first time since her initial diagnosis and the patient has remained disease-free for >6 years. Azacitadine and nab-paclitaxel combination appeared to be an effective regimen for the treatment of this patient with refractory DLBCL.

Abstract C111: Safety profile and tumor response in patients with refractory superficial cancers treated with HF10, an oncolytic replication-competent HSV-1-derived intratumoral injectable, as monotherapy and combined with ipilimumab

Background:

Here, we report on safety, recommended HF10 dose, viral shedding in body fluids and overall (all target lesions) and local (injected lesion) antitumor activity in patients (pts) with superficial tumors (13 squamous cell carcinoma, 9 malignant melanoma and 4 other tumor types) in a Phase 1 monotherapy study. In addition, we report on preliminary safety data and antitumor activity of HF10 + ipilimumab combination in an ongoing Phase 2 trial in pts with unresectable or metastatic melanoma.

Methods:

In Stage 1 of the Phase 1 study, a single HF10 injection was administered to a superficial/cutaneous lesion; in Stage 2, up to 4 injections (≥ 2 weeks apart) were given. Adverse events (AEs) were assessed per CTCAE 3.0. Tumor responses were assessed per RECIST 1.0.

In the ongoing Phase 2 study, HF10 is injected into single or multiple tumors (at 1 × 107 TCID50/mL, up to 5mL depending on tumor size and number); 4 injections at 1-week intervals; then up to 15 injections at 3-week intervals. Four ipilimumab IV infusions (3 mg/kg; concurrent with HF10) are administered at 3-week intervals. AEs are assessed per CTCAE 4.0. Tumor responses are assessed per mWHO and irRC.

Results:

Of 26 pts treated in the Phase 1 study, 24 pts had AEs. Nine (35%) pts had HF10-related AEs including chills (n = 3), fatigue (n = 2) and injection site reactions (n = 6). There were no ≥ Grade 3 (G3) HF10-related AEs. HF10 was rapidly cleared from blood, saliva and urine. Pt HSV-1 serostatus did not affect AE profile or HF10 clearance. Of 24 evaluable pts at end of study (EOS; ≥ 10 wks after start of HF10), none had complete (CR) or partial response; 7 had local stable disease (SD); 8 had overall SD, and 6 of 9 melanoma pts had overall SD. Although there were no partial responders per RECIST, but 1 melanoma pt had a 45% decrease in injected tumor size and another melanoma pt had 3 uninjected lesions disappear, despite overall SD. In long-term follow-up after EOS, 3 other melanoma pts had delayed responses in HF10-injected lesions: 1pt with an injected thigh tumor had pathological CR on resection and remains disease free 1.5 yrs later, 1 pt with an injected submandibular lymph node (LN) had CR and remains disease free, and 1 pt had CR in an injected neck LN, but has slowly progressed in a lung metastasis. None of these 3 pts received any additional treatment after completing HF10 injections.

In the ongoing Phase 2, 24 pts have been treated and HF10-related AEs reported thus far are similar to those previously reported for HF10 monotherapy and none are ≥ G3. Of note, the commonly reported ≥ G3 immune-mediated ipilimumab-related events of colitis, hepatitis and endocrinopathies have not been observed. Four efficacy evaluable and 2 pts on-study &lt; 12 wks (not yet evaluable) are showing a decrease in lesion size in response to treatment, with 2 documented local CRs.

Conclusions:

Intratumoral HF10 serial injections are safe and well-tolerated, in monotherapy (Phase 1) and in combination with ipilimumab (preliminary Phase 2). HF10-related AEs include chills, fatigue and injection site reactions. Efficacy evaluation (overall and local) suggests that HF10 has both local and systemic antitumor activity in melanoma and can result in delayed responses. Assessment of HF10 as a potential new treatment for melanoma pts is ongoing in a Phase 2 study.

Citation Format: Robert H.I. Andtbacka, Kenneth F. Grossmann, Hung T. Khong, Maki Tanaka, Richard S. Ungerleider, Aislyn D. Boran, Robert L. Ferris. Safety profile and tumor response in patients with refractory superficial cancers treated with HF10, an oncolytic replication-competent HSV-1-derived intratumoral injectable, as monotherapy and combined with ipilimumab. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr C111.

Abstract LB-242: MicroRNA-125b, a key mediator for Snail-induced stem cell propagation and chemoresistance

MicroRNAs (miRNAs) are short ribonucleic acid molecules commonly deregulated in various tumors. Our previous studies have shown that miR-125b plays a major role in the chemoresistance of breast cancer. Snail, a transcription factor important in epithelial-mesenchymal transition, has been reported to be responsible for tumor metastasis and recurrence, however, the mechanism by which Snail exerts these effects is not understood. We report a novel mechanism in which upregulation of miR-125b through Wnt signaling by Snail enriches cancer stem cells and confers chemoresistance. We found that Snail is upregulated in chemoresistant cancer cells. Overexpressing Snail increases miR-125b expression by activating the Wnt/beta-catenin/TCF4 axis, while silencing Snail decreases miR-125b expression. Snail activates Wnt signaling by interacting with beta-catenin/TCF4 to activate the expression of target genes. We discovered 5 TCF4 binding sites in the miR-125b promoter. The full length miR-125b promoter showed higher activity with Snail overexpression, and deletion of TCF4 binding sites decreased the promoter activity of miR-125b in a dose-dependent manner. Knockdown of TCF4 decreased miR-125b expression, which confirms that TCF4 is required for Snail to fully activate the miR-125b promoter.

Bak1 is a pro-apoptosis molecule and confirmed target of miR-125b. Deregulation of Bak1 is important in cancer development and drug resistance. Since overexpression of Snail confers chemotherapeutic resistance, and Snail was upregulated in Paclitaxel-resistant cells, we examined whether Snail induces drug resistance through Bak1. We found low Bak1 expression in Paclitaxel-resistant cells, which have high expression of Snail. To verify whether Snail regulates Bak1 expression, we expressed Snail in Snail-low expressing cells and saw repression of Bak1 expression. To confirm, we knocked-down Snail in Snail-high expressing cells, which resulted in increased Bak1 expression. Overexpression of Snail or miR-125b increased the resistance of cancer cells to chemotherapy. Inhibiting miR-125b expression or restoring Bak1 expression re-sensitized cells to chemotherapy. These results indicate that Snail increases chemoresistance by repressing Bak1 through miR-125b.

Overexpression of miR-125b significantly increases the cancer stem cell population, while depletion of miR-125b or rescue of Bak1 expression increases the non-stem cell population. These findings support that miR-125b functions as a key mediator in Snail-induced cancer stem cells and chemoresistance. This novel mechanism for Snail-induced stem cell propagation and chemoresistance may have important implications in the development of strategies for overcoming chemotherapy resistance.

Work supported by: Vincent F. Kilborn Jr. Cancer Research Foundation, NIH Grant R01CA149646, and the Norwegian Hospitalet Legater Project 334003.

Citation Format: Zixing Liu, Hao Liu, Shruti Desai, David C. Schmitt, Ming Zhou, Hung T. Khong, Kristine S. Klos, Steven McClellan, Oystein Fodstad, Ming Tan. MicroRNA-125b, a key mediator for Snail-induced stem cell propagation and chemoresistance. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-242. doi:10.1158/1538-7445.AM2013-LB-242

miR-125b functions as a key mediator for snail-induced stem cell propagation and chemoresistance

Chemoresistance is a major obstacle in cancer treatment. Our previous studies have shown that miR-125b plays an important role in chemoresistance. Here we report a novel mechanism that up-regulation of miR-125b through Wnt signaling by Snail enriches cancer stem cells. Overexpression of Snail dramatically increases the expression of miR-125b through the Snail-activated Wnt/β-catenin/TCF4 axis. Snail confers chemoresistance by repressing Bak1 through up-regulation of miR-125b. Restoring the expression of Bak1 or depleting miR-125b re-sensitizes Snail-expressing cancer cells to Taxol, indicating that miR-125b is critical in Snail-induced chemoresistance. Moreover, overexpression of miR-125b significantly increases the cancer stem cell population (CD24-CD44+), while depletion of miR-125b or rescue of the expression of Bak1 increases the non-stem cell population (CD24+CD44+) in Snail-overexpressing cells. These findings strongly support that miR-125b functions as a key mediator in Snail-induced cancer stem cell enrichment and chemoresistance. This novel mechanism for Snail-induced stem cell propagation and chemoresistance may have important implications in the development of strategies for overcoming cancer cell resistance to chemotherapy.

Activated CD4+ T cells enhance radiation effect through the cooperation of interferon-gamma and TNF-alpha

Background

Approaches that enhance radiation effect may lead to improved clinical outcome and decrease toxicity. Here we investigated whether activated CD4+ T cells (aCD4) can serve as an effective radiosensitizer.

Methods

CD4+ T cells were activated with anti-CD3 and anti-CD28 mAbs. Hela cells were presensitized with aCD4 or conditioned supernatant (aCD4S) or recombinant cytokines for 2 days, followed γ-irradiation. The treated cells were cultured for an additional 2 to 5 days for cell proliferation, cell cycle, and western blot assays. For confirmation, other cancer cell lines were also used.

Results

Presensitization of tumor cells with aCD4 greatly increased tumor cell growth inhibition. Soluble factors secreted from activated CD4⁺ T cells were primarily responsible for the observed effect. IFN-γ seemed to play a major role. TNF-α, though inactive by itself, significantly augmented the radiosensitizing activity of IFN-γ. aCD4S, but not IFN-γ or IFN-γ/TNF-α combination, was found to enhance the γ-irradiation-induced G2/M phase arrest. Bax expression was highly upregulated in Hela cells presensitized with aCD4S followed by γ-irradiation. The radio-sensitizing activity of aCD4 is not uniquely observed with Hela cell line, but also seen with other cancer cell lines of various histology.

Conclusions

Our findings suggest possible molecular and cellular mechanisms that may help explain the radio-sensitization effect of activated lymphocytes, and may provide an improved strategy in the treatment of cancer with radiotherapy.

Mitf-Mdel, a novel melanocyte/melanoma-specific isoform of microphthalmia-associated transcription factor-M, as a candidate biomarker for melanoma

BACKGROUND

Melanoma incidence is on the rise and advanced melanoma carries an extremely poor prognosis. Treatment options, including chemotherapy and immunotherapy, are limited and offer low response rates and transient efficacy. Thus, identification of new melanocyte/melanoma antigens that serve as potential novel candidate biomarkers in melanoma is an important area for investigation.

METHODS

Full length MITF-M and its splice variant cDNA were cloned from human melanoma cell line 624 mel by reverse transcription polymerase chain reaction (RT-PCR). Expression was investigated using regular and quantitative RT-PCR in three normal melanocytes (NHEM), 31 melanoma cell lines, 21 frozen melanoma tissue samples, 18 blood samples (peripheral blood mononuclear cell; PBMC) from healthy donors and 12 non-melanoma cancer cell lines, including three breast, five glioma, one sarcoma, two kidney and one ovarian cancer cell lines.

RESULTS

A novel splice variant of MITF-M, which we named MITF-Mdel, was identified. The predicted MITF-Mdel protein contains two in frame deletions, 56- and 6- amino acid deletions in exon 2 (from V32 to E87) and exon 6 (from A187 to T192), respectively. MITF-Mdel was widely expressed in melanocytes, melanoma cell lines and tissues, but almost undetectable in non-melanoma cell lines or PBMC from healthy donors. Both isoforms were expressed significantly higher in melanoma tissues than in cell lines. Two of 31 melanoma cell lines expressed only one isoform or the other.

CONCLUSION

MITF-Mdel, a novel melanocyte/melanoma-specific isoform of MITF-M, may serve as a potential candidate biomarker for diagnostic and follow-up purposes in melanoma.

Immunotherapy of melanoma: a critical review of current concepts and future strategies

Advanced melanoma is a devastating disease with a very poor overall prognosis. There are only two agents that are approved by the FDA for use in patients with metastatic melanoma: dacarbazine and IL-2. Both agents have an overall response rate well below 20%, with only rare long-term responders noted. Metastatic melanoma is known to be one of the most resistant cancers to a plethora of treatment modalities, such as single-agent and combination chemotherapy, chemoimmunotherapy and immunotherapy with a host of immune stimulators. Indeed, researchers worldwide have recognized the lack of effective therapies and have refocused their efforts on developing novel and cutting-edge strategies of treatment. This is based on an improved understanding of the complex interactions that occur within the tumor microenvironment, and the central role that the host immune system plays in the surveillance of cancer. This review summarizes the recent results of novel immunotherapeutic regimens and focuses on cutting-edge modalities of treatment that encompass new lines of thinking in the war against cancer and, in particular, melanoma.

Transduction of an HLA-DP4-restricted NY-ESO-1-specific TCR into primary human CD4+ lymphocytes

cDNAs encoding functional T cell receptor (TCR) alpha and beta chains from a CD4+ T cell line (SG6) generated by repeated stimulation of a melanoma patient's peripheral blood mononuclear cells with HLA-DP4-restricted, NY-ESO-1-specific peptide p161-180 were cloned using a 5'rapid amplification of cDNA end method. Three different TCR alpha chains and 7 TCR beta chains were found among the 84 alpha and 162 beta cDNA clones tested. By screening different combination of the alpha/beta chains using RNA electroporation, TRAV9-1 (Valpha22.1) and TRBV20-1 (Vbeta2) were found to be the functional pair in line SG6. Antibody blocking experiments confirmed that the specificity of TRAV9-1/TRBV20-1 mRNA-transfected T cells were CD4 dependent and HLA-DP4 restricted. A retroviral vector expressing both TRAV9-1 and TRBV20-1 was constructed and used for transduction of OKT3-stimulated peripheral blood lymphocytes from melanoma patients. TCR-transduced CD4 T cells were capable of recognizing peptide-pulsed antigen-presenting cells (Epstein-Barr virus transformed B-cells, dendritic cells, and peripheral blood mononuclear cells), and protein-pulsed dendritic cells. Transduced cells were also capable of proliferation upon peptide stimulation and recognized peptide concentrations that were recognized by the parental line (0.2 microM). In contrast to SG6, which could not recognize human tumors, TCR-transduced CD4 T cells could specifically recognize NY-ESO-1/HLA-DP4-expressing melanoma cells. Major histocompatibility complex class II TCR-transduced CD4 T cells provides an alternative source of tumor antigen-specific T cells for adoptive immunotherapy of cancer patients.

Generating Renal Cancer-Reactive T Cells Using Dendritic Cells (DCs) to Present Autologous Tumor

Dendritic cells (DCs) have been used as professional antigen-presenting cells in vitro to prime T-cell responses. In this study, we generated both CD8+ and CD4+ renal cell carcinoma (RCC)-reactive T cells using a completely autologous system of DCs presenting engulfed whole-tumor cells. We compared DCs presenting RCC tumor cells in different preparations and found ultraviolet-irradiated apoptotic tumor cells to be more immunogenic than necrotic tumor cells or live untreated tumor cells in generating tumor-reactive T cells. In analyzing the T cells generated in this fashion, a CD8+ RCC-reactive T-cell clone generated from a patient recognized an epitope derived from fibroblast growth factor 5 in the context of human leukocyte antigen (HLA) B44*02. CD4+ T cells generated from another patient recognized multiple allogeneic RCC lines expressing HLA-DRbeta1*04, indicating a common shared tumor antigen presented by HLA-DRbeta1*04. The technique of using DCs to present whole-tumor cells can consistently generate both CD4+ and CD8+ RCC-reactive T cells for use in both antigen identification and therapeutic protocols.

Survival, persistence, and progressive differentiation of adoptively transferred tumor-reactive T cells associated with tumor regression

Objective clinical responses have been observed in approximately 50% of patients who received non-myeloablative chemotherapy prior to the adoptive transfer of autologous melanoma-reactive tumor-infiltrating lymphocytes (TILs). Recent studies carried out through the use of antibodies directed against T-cell-receptor beta chain variable region (TRBV) products, as well as by direct sequencing of the expressed TRBV gene products, indicated that clinical responses in this trial were associated with the level of persistence of adoptively transferred T cells. In an attempt to further characterize T cells that persist in vivo following adoptive transfer, five dominant T-cell clonotypes were identified in TIL 2035, an adoptively transferred TIL that was associated with the complete regression of multiple metastases. The most highly persistent clonotype, which expressed the BV1 TR gene product, recognized the MAGE-6 cancer/testis antigen in the context of HLA-A23. This clonotype was detected in peripheral blood for over 16 months following adoptive transfer, expressed relatively higher levels of the co-stimulatory markers CD28 and CD27, and possessed telomeres that were long relative to other clonotypes present in TIL 2035 that showed only short-term persistence. The long-term persistent BV1 clonotype appeared to differentiate more slowly toward an end-stage effector in vivo than short-term persistent clonotypes, as manifested by the downregulation of CD28, CD27, and CD45RO and upregulation of CD57 and CD45RA expression on these T cells. These results indicated that the differentiation stage and replicative history of individual TIL clonotypes might be associated with their ability to survive and to persist in vivo, and progressive differentiation of the persistent clonotypes occurred following adoptive transfer.

Primary human lymphocytes transduced with NY-ESO-1 antigen-specific TCR genes recognize and kill diverse human tumor cell lines

cDNAs encoding TCR alpha- and beta-chains specific for HLA-A2-restricted cancer-testis Ag NY-ESO-1 were cloned using a 5'RACE method from RNA isolated from a CTL generated by in vitro stimulation of PBMC with modified NY-ESO-1-specific peptide (p157-165, 9V). Functionality of the cloned TCR was confirmed by RNA electroporation of primary PBL. cDNA for these alpha- and beta-chains were used to construct a murine stem cell virus-based retroviral vector, and high titer packaging cell lines were generated. Gene transfer efficiency in primary T lymphocytes of up to 60% was obtained without selection using a method of precoating retroviral vectors onto culture plates. Both CD4(+) and CD8(+) T cells could be transduced at the same efficiency. High avidity Ag recognition was demonstrated by coculture of transduced lymphocytes with target cells pulsed with low levels of peptide (<20 pM). TCR-transduced CD4 T cells, when cocultured with NY-ESO-1 peptide pulsed T2 cells, could produce IFN-gamma, GM-CSF, IL-4, and IL-10, suggesting CD8-independent, HLA-A2-restricted TCR activation. The transduced lymphocytes could efficiently recognize and kill HLA-A2- and NY-ESO-1-positive melanoma cell lines in a 4-h (51)Cr release assay. Finally, transduced T cells could efficiently recognize NY-ESO-1-positive nonmelanoma tumor cell lines. These results strongly support the idea that redirection of normal T cell specificity by TCR gene transfer can have potential applications in tumor adoptive immunotherapy.

Cytotoxic T cell targeting of TRP-2 sensitizes human malignant glioma to chemotherapy

Tyrosinase-related protein (TRP)-2 is not only expressed on glioma cells, but is naturally processed and presented by their surface MHC molecules and is recognized by TRP-2-specific cytotoxic T cells. After active immunotherapy, we detected TRP-2-specific cytotoxic T lymphocyte (CTL) activity in patients' peripheral blood mononuclear cells (PBMC). Tumor cells from postvaccination resections showed significantly lower TRP-2 expression and higher sensitivity to carboplatin and temozolomide than those autologous cell lines from prevaccination resections in two patients who demonstrated CTL response to TRP-2. One of two patients underwent treatment with temozolomide after recurrence and responded dramatically. TRP-2-transfected cell line (TRP-2-U373) resulted in significant drug resistance to carboplatin and temozolomide compared to wild-type U-373 (W-U373). There was no significant difference, however, in the mRNA expression of other common drug resistance related proteins, such as BCRP-1, MGMT, MDR-1, MRP-1 and MRP-3, after TRP-2 transfection. TRP-2-U373 tumor cells were immunoselected by a TRP-2-specific CTL line. The immunoselected cells (IS-TRP-2-U373) demonstrated significantly increased sensitivity to carboplatin and temozolomide compared to TRP-2-U373. For the first time, we provide evidence that immunological targeting of tumor-associated antigen TRP-2 significantly increases sensitivity to chemotherapy.

Immunization of HLA-A*0201 and/or HLA-DPbeta1*04 patients with metastatic melanoma using epitopes from the NY-ESO-1 antigen

HLA class I-restricted peptides are often used in peptide vaccine regimens. There is strong evidence that many of these peptides can generate specific CD8 T-cell responses in vivo; however, only occasional objective clinical responses have been reported. To test whether provision of "help" would enhance antitumor immunity, the authors initiated a clinical trial in which patients with metastatic melanoma were immunized against the NY-ESO-1 tumor antigen, using an HLA-A2-restricted peptide (ESO-1:165V), an HLA-DP4-restricted peptide (NY-ESO-1:161-180), or both peptides given concomitantly. The first cohorts received only ESO-1:165V, using three vaccination schedules. Immunologically, most patients developed immune responses to the HLA-A2-restricted native ESO-1 epitope after vaccination. Peptide vaccine given daily for 4 days appeared to induce immunologic responses more rapidly than if given once a week or once every 3 weeks. In contrast, vaccination using the NY-ESO-1:161-180 peptide induced immune responses in only a few patients. Clinically, one patient who received NY-ESO-1:161-180 peptide alone had a partial response lasing 12 months. Concomitant vaccination with the HLA class II-restricted peptide did not alter the immune response to the HLA class I-restricted peptide form NY-ESO-1. However, vaccination with the HLA-A2-restricted epitope generated primarily T cells that did not recognize tumor after in vitro sensitization. This result raises questions about the use of synthetic peptides derived from NY-ESO-1 as a sole form of immunization.

Identification of multiple antigens recognized by tumor-infiltrating lymphocytes from a single patient: tumor escape by antigen loss and loss of MHC expression

The authors describe a patient who experienced recurrence of metastatic melanoma after an initial dramatic response to immunotherapy using peptides derived from gp100, MART-1, and tyrosinase emulsified in incomplete Freund's adjuvant, and present data to support the hypothesis that the progression of disease in this patient was due to in vivo immunoselection for immunoresistant tumor variants. The authors previously demonstrated the existence of T-cell clones in this patient's peripheral blood and tumor-infiltrating lymphocytes (TILs) reactive against multiple antigens, including gp100, the tyrosinase-related protein (TRP)-2, a novel TRP-2 isoform-TRP-2-6b, SOX10, and the melanoma antigen NY-ESO-1. In addition to the multiple HLA-A2 restricted T-cell clones, the authors have now identified additional HLA-B/C-restricted as well as class II (HLA-DP)-restricted anti-melanoma antigen T-cell clones from this patient's TIL. One recurrent tumor showed loss of expression of multiple tumor antigens but retention of HLA class I expression. The other recurrent lesion showed total loss of HLA class I expression even though the tumor cells still expressed many melanoma antigens. This paper thus provides evidence for both the effectiveness of the immune destruction of cancer as well as problems associated with antigen-loss tumor escape mechanisms.

Molecular and functional analysis of tyrosinase-related protein (TRP)-2 as a cytotoxic T lymphocyte target in patients with malignant glioma

Tyrosinase-related protein (TRP)-2 is an immunogenic antigen in melanoma. The authors sought to investigate whether TRP-2 could be a potential target for patients with malignant glioma. RT-PCR analysis demonstrated that TRP-2 was present in 51.2% of primary tumor cell lines derived from patients with glioblastoma multiforme (GBM). The percentage of TRP-2-6b, TRP-2-INT2, TRP-2-LT, and TRP-2-8b isoform expression in all tested GBM cells was 13.9%, 34.9%, 41.9%, and 39.5%, respectively. TRP-2 protein expression was detected in GBM cells and tumor tissues by Western blot and immunohistochemistry. In addition, an HLA-A2-restricted cytotoxic T cell clone that recognizes the TRP-2(180-188) peptide (SVYDFFVWL) specifically lysed the TRP-2 positive GBM cells in a HLA-A2 restricted manner. In addition, the level of TRP-2 mRNA expression, as determined by real-time quantitative RT-PCR, correlated with the level of CTL recognition as measured by IFN-gamma secretion (R = 0.90; p < 0.01). To further test the immunogenicity of TRP-2 in glioma, PBMCs from a healthy donor were primed in vitro using autologous dendritic cells (DCs) pulsed with irradiated GBM cells. These in vitro generated T cells specifically lysed T2 cells pulsed with TRP-2(180-188) peptide and TRP-2 positive GBM cell lines. Most importantly, TRP-2(180-188) specific CTL frequency in four patients' PBMC who were both HLA-A2 and TRP-2 positive was significantly (p < 0.01) increased, respectively, after vaccinations with DCs pulsed with autologous tumor lysate. The authors' studies demonstrate that TRP-2 could be a useful antigen target for monitoring or developing immunotherapeutic strategies for glioma patients.

Natural selection of tumor variants in the generation of "tumor escape" phenotypes

The idea that tumors must "escape" from immune recognition contains the implicit assumption that tumors can be destroyed by immune responses either spontaneously or as the result of immunotherapeutic intervention. Simply put, there is no need for tumor escape without immunological pressure. Here, we review evidence supporting the immune escape hypothesis and critically explore the mechanisms that may allow such escape to occur. We discuss the idea that the central engine for generating immunoresistant tumor cell variants is the genomic instability and dysregulation that is characteristic of the transformed genome. "Natural selection" of heterogeneous tumor cells results in the survival and proliferation of variants that happen to possess genetic and epigenetic traits that facilitate their growth and immune evasion. Tumor escape variants are likely to emerge after treatment with increasingly effective immunotherapies.

The Waardenburg syndrome type 4 gene, SOX10, is a novel tumor-associated antigen identified in a patient with a dramatic response to immunotherapy

In this study, we have identified, for the first time, the presence of de novo cellular immune reactivity against the transcription factor SOX10, using tumor-infiltrating lymphocytes obtained from a patient who experienced a dramatic clinical response to immunotherapy. SOX10 acts as a critical transactivator of tyrosinase-related protein-2 during melanoblast development and a potent transactivator of micropthalmia-associated transcription factor, which is considered to be a master gene that controls the development and postnatal survival of melanocytes. Mutations in SOX10 result in Waardenburg syndrome type 4. The overlapping epitopes AWISKPPGV and SAWISKPPGV, designated SOX10: 332-340 and SOX10: 331-340, respectively, were recognized by tumor-infiltrating lymphocyte clone M37 in an HLA-A2-restricted fashion.

Pre-existing immunity to tyrosinase-related protein (TRP)-2, a new TRP-2 isoform, and the NY-ESO-1 melanoma antigen in a patient with a dramatic response to immunotherapy

We have performed a detailed analysis of the recognition of melanoma Ags by the tumor-infiltrating lymphocytes (TIL) 1790, isolated from a patient who experienced a dramatic tumor regression following immunization with peptides from the gp100, MART-1, and tyrosinase Ags. This TIL was found to recognize HLA-A2-restricted CTL epitopes in tyrosinase-related protein (TRP)-2 (clone MR7) and NY-ESO-1 (clone M8). These epitopes were the same as the previously identified nonapeptide TRP-2: 180-188, and the overlapping NY-ESO-1 peptides, obtained by using lymphocytes from in vitro stimulation. We also cloned a previously unknown TRP-2 mRNA isoform (TRP-2-6b) that contained two novel exons alternatively spliced from the sixth intron between exons 6 and 7 of TRP-2 mRNA. The isoform encoded an HLA-A2-restricted antigenic epitope recognized by TIL clone MB4. An immunologic analysis of the patient's PBMC obtained before treatment showed the presence of high reactivity against NY-ESO-1 and both TRP-2 Ags, but not the Ags used for immunization. Because immune response against these Ags was less pronounced, it is possible that NY-ESO-1, TRP-2, and TRP-2-6b may be of importance in the generation of CTL-mediated tumor destruction and may have played a role in the dramatic tumor regression seen in this patient.

Identification of endogenous HLA-A2-restricted reactivity against shared melanoma antigens in patients using the quantitative real-time polymerase chain reaction

This study was conducted to determine whether reactivity to melanoma cells of pretreatment peripheral blood mononuclear cells (PBMCs) from patients with metastatic melanoma correlated with subsequent response to treatment with interleukin-2 (IL-2). The sensitivity of the quantitative real-time polymerase chain reaction (PCR) assay was optimized, including the total number of cells used (3 x 10(6) in 1 mL), the responder-to-stimulator cell ratio (5:1), the optimal time to incubate PBMCs with tumor (2 h), the appropriate tumor stimulators (melanoma cell lines differing only in the expression of histocompatibility leukocyte antigen [HLA-A2]), the duration of recovery in the culture of PBMCs after cryopreservation (18-24 h), and the medium used (Iscove, 10% human AB serum). Using this optimized assay to detect HLA-A2-restricted antitumor reactivity in the pretreatment PBMCs from patients with melanoma, positive reactive responses were detected in 7 of 28 patients with an objective clinical response to IL-2 therapy compared with 6 of 21 positive reactive responses in nonresponding patients. None of 12 healthy donors were positive in this study. Thus, there was no significant difference in the reactivity of pretreatment PBMCs when responders were compared with nonresponders, although the melanoma patients had an increased incidence of response compared with healthy donors (p = 0.05). The PBMCs from 11 of the 13 melanoma patients with pretreatment HLA-A2-restricted antimelanoma reactivity were tested against a panel of transfectants expressing known shared melanoma antigens. Anti-MART-1 reactivity was detected in the pretreatment PBMCs of three patients. It thus appears that some melanoma patients are immunologically primed to antigens expressed on the tumor surface, although the HLA-A2-restricted antimelanoma activity detected in this real-time PCR assay was not predictive of patients' responses to IL-2 therapy.

Chlorambucil-induced pulmonary disease: a case report and review of the literature

A 77-year-old man developed pneumonitis while on chlorambucil therapy for chronic lymphocytic leukemia, with a cumulative dose of 2700 mg. The condition improved promptly with the discontinuation of the drug and initiation of steroids. A case report and review of the literature are presented in this paper.