Response to OKN-007 and NAC in a Patient with Unilateral Hearing Loss and Chronic Tinnitus from Vestibular Schwannoma

BACKGROUND

Tinnitus is the perception of sound in the absence of external acoustic stimulation. Being one of the most common diseases of the ear, it has a global prevalence ranging from 4.1 to 37.2%. To date, it has been difficult to treat tinnitus as its pathophysiology is poorly understood and there are limited treatment options.

OBJECTIVE

To investigate the effect of OKN-007 (also known as HPN-07), a nitrone-based investigational drug, in combination with oral N-acetylcycsteine (NAC), for the treatment of hearing loss and chronic tinnitus under an individual expanded access protocol.

PATIENT CASE

We report the case of a patient who presented with left-sided ear fullness, mild tinnitus, and mild high frequency sensorineural hearing loss with 100% word recognition. A large enhancing mass seen on MRI revealed a vestibular schwannoma. He underwent subtotal resection of the tumor resulting in a moderate-to-profound sensorineural hearing loss and catastrophic tinnitus. The patient was treated with intravenous OKN-007 at 60 mg/kg dosed three times per week and oral NAC 2500 mg twice daily.

RESULTS

Post-treatment audiometric testing revealed an average of 16.66 dB in hearing threshold improvement in three frequencies (125, 250 and 500 Hz) with residual hearing in the affected left ear. His tinnitus loudness matching improved from 90 dB to 19 dB post-treatment. His Tinnitus Handicap Inventory improved from 86/100 (Catastrophic) to 40/100 (Moderate). He also experienced improvements in sleep, concentration, hearing, and emotional well-being, and reported significantly decreased levels of tinnitusrelated distress.

CONCLUSIONS

This case report highlights the feasibility and therapeutic potential of the combination of OKN-007 and NAC in treating hearing loss and tinnitus that warrants further investigation.

Activity of pemetrexed in pre-clinical chordoma models and humans

Chordomas are rare slow growing tumors, arising from embryonic remnants of notochord with a close predilection for the axial skeleton. Recurrence is common and no effective standard medical therapy exists. Thymidylate synthase (TS), an intracellular enzyme, is a key rate-limiting enzyme of DNA biosynthesis and repair which is primarily active in proliferating and metabolically active cells. Eighty-four percent of chordoma samples had loss of TS expression which may predict response to anti-folates. Pemetrexed suppresses tumor growth by inhibiting enzymes involved in folate metabolism, resulting in decreased availability of thymidine which is necessary for DNA synthesis. Pemetrexed inhibited growth in a preclinical mouse xenograft model of human chordoma. We report three cases of metastatic chordoma that had been heavily treated previously with a variety of standard therapies with poor response. In two cases, pemetrexed was added and objective responses were observed on imaging with one patient on continuous treatment for > 2 years with continued shrinkage. One case demonstrated tumor growth after treatment with pemetrexed. The two cases which had a favorable response had a loss of TS expression, whereas the one case with progressive disease had TS present. These results demonstrate the activity of pemetrexed in recurrent chordoma and warrant a prospective clinical trial which is ongoing (NCT03955042).

QLTI-26. INTEGRATION OF NEURO-ONCOLOGY CLINICAL PATHWAYS IN PROVIDENCE SOUTHERN CALIFORNIA CLINICAL RESEARCH NETWORK

INTRODUCTION

ClinicalPath is an evidence-based oncology decision support and analytics tool for cancer care. ClinicalPath’s treatment recommendations are prioritized based on efficacy, toxicity, and cost by a nationwide committee of oncologists. The pathways are updated quarterly and are expected to speed the integration of new treatments into practice, standardize therapy, improve quality, and decrease cost. The pathway system also allows for local clinical trial mapping to promote clinical trial awareness and increase enrollment. ClinicalPath provides clinical pathways delivering personalized, evidence-based oncology guidance at the point of care. ClinicalPath’s network in North America serves more than 2,000 cancer physicians, within 54 practices in 31 states (15 academic medical centers, 29 hospital systems, and 9 community practices). Population: Our population is derived from multiple hospitals in Southern California within the Providence Health System. Methodology: Medical oncologists and Advanced Practice Providers received training on ClinicalPath before go-live. ClinicalPath was integrated into the Epic EHR in multiple Southern CA hospitals in a single month.

RESULTS

After 3 months of utilization within our Southern California region, 342 treatment decisions were made across all cancers, and 85.1% of cancer patients were treated on pathway. Of which, 7 treatment decisions were made within the neuro-oncology specialty, and 85.7% of those cancer patients were treated on pathway.

CONCLUSION

We successfully integrated and initiated ClinicalPath in a multiple hospital-affiliated community oncology clinical trial network. We are actively working across our Southern California Region to map locally available clinical trials to promote awareness and increase enrollment. Provider utilization and patient on-pathway rates are actively monitored and will be updated.

QLTI-22. IMPROVING BRAIN CANCER PATIENT ACCESS TO CLINICAL TRIALS ACROSS SEVEN COMMUNITY HOSPITALS, THE PROVIDENCE SOUTHERN CALIFORNIA CLINICAL RESEARCH NETWORK

Despite current FDA approved treatments for glioblastoma (GBM), prognosis remains poor. The rare patient population and limited access to clinical trials are factors in this poor prognosis. Clinical trials need to increase enrollment of patients with glioblastoma and other brain cancers to more rapidly develop more effective treatments. Clinical trials are featured on NCCN guidelines, and are considered “Standard of Care” by many experts. Multiple studies have shown that access to clinical trials is associated with improved survival in GBM, however, less than 25% of patients have access or are offered clinical trials. Access to clinical trials can be even more limited in community hospitals, while a large proportion of brain tumors are treated in smaller centers. Community hospitals care for a significant number of brain tumors annually. We have developed a Clinical Research Network for Neuro-Oncology within the Providence Network involving seven hospitals to date. In the past 3 years, we have grown the number of clinical trials available in outlying cities and counties spanning a distance of 60 miles. Between the seven hospitals in our network, we have 15 clinical trials currently open for brain cancer patients, of which, 3 trials were phase I studies. Over the past 2 years, we have enrolled 104 GBM patients in clinical trials. The ability to enhance access to clinical trials by Neuro-Oncologists treating patients in the community is feasible and promising.

DDRE-09. MULTI-INSTITUTION RETROSPECTIVE EXPERIENCE WITH LENVATINIB FOR PROGRESSIVE MALIGNANT GLIOMA

Despite treatment with radiation and temozolomide chemotherapy, malignant gliomas inevitably recur after treatment and have poor prognosis. Clinical trials should be offered when available, but effective treatment options for multiply recurrent tumors is sparse. In our multi-institutional retrospective cohort, we looked at recurrent malignant gliomas treated with Lenvatinib multi-kinase inhibitor. Patients consented to an IRB-approved study protocol that allows for longitudinal history review and analysis at our institution. Lenvatinib is a targeted therapy that is FDA approved for Differentiated Thyroid Cancer, Renal Cell Carcinoma, Hepatocellular Carcinoma, and Endometrial Carcinoma. Lenvatinib binds to tyrosine kinase receptors inhibiting kinase activity by VEGFR1-3, FGFR1-4, PDGFRa, FGF, KIT, and RET. In this cohort, patients received radiation and temozolomide chemotherapy, N=15, median age was 45.5, and 47% were male. At time of surgery 40% underwent biopsy, 40% had STR, and 20% had GTR. Glioblastoma was the most common tumor type at 87%, 6.7% were recurrent anaplastic astrocytoma, and 6.7% were recurrent glioma NOS. IDH mutation was seen in 13% of our cohort, and MGMT methylation was seen in 27%, all patients had available IDH and MGMT data. Patients were heavily treated, median number of recurrences was 3. Patient mean PFS was 2.7 months, and median OS was 24.0 months. Clincal Benefit Rate (PR+SD) to Lenvatinib in recurrent disease was 57%, with 29% Partial Responses and 29% Stable Disease as best radiographic response. This retrospective cohort supports further evaluation of the efficacy of Lenvatinib in recurrent malignant glioma in a clinical trial.

CTNI-46. PHASE I OPEN-LABEL, SINGLE-CENTER, DOSE ESCALATION STUDY (NCT02423525) OF PULSATILE AFATINIB IN PATIENTS WITH BRAIN CANCER

Afatinib is a small molecule, selective and irreversible ErbB family blocker. In preclinical models it effectively inhibits EGFR, HER2 and HER4 phosphorylation resulting in tumor growth inhibition and is approved for the treatment of EGFR-mutated metastatic non-small cell lung carcinoma and metastatic squamous cell lung carcinoma. Pulse dosing afatinib could potentially increase CNS exposure to reach therapeutic levels while allowing a recovery period to mitigate toxicities. We are reporting the results of a Phase I open-label, single-center, ‘3 + 3’ dose escalation study to determine the safety and tolerability of pulsatile Afatinib in patients with brain cancer and to define a recommended phase 2 dose. The study assessed the exposure of Afatinib in cerebrospinal fluid and serum, objective tumor response according to RANO criteria, progression-free survival, and overall survival, and will explore the association between molecular phenotypes and patient response. In total, 26 patients were screened and 24 were enrolled (median age 60, 78% male, 87.5% Caucasian, glioblastoma N=16, chordoma N=3, brain metastases N=2, meningioma N=1, anaplastic mixed oligoastrocytoma N=1). Patients had received a median of 2.5 prior treatments. The study proceeded through the 4 dosing cohorts without reaching dose-limiting toxicity: Cohort 1 (80mg every 4 days) N=3; Cohort 2 (120mg every 4 days) N=3; Cohort 3 (180mg every 4 days) N=7, including replacement patients; Cohort 4 (280mg every 7 days) N=11. Diarrhea (75%), rash (75%), nausea/vomiting (37.5%), fatigue (29.2%), anorexia (25%), and limb edema (16.7%) were the most common side effects. There were no CTCAE defined grade 4 toxicities. Grade 3 side effects infrequently occurred in the highest dosing cohort and once in each cohort 2 and 3. These results demonstrate that pulsatile Afatinib at a dose of 280mg every 7 days is safe and tolerable for patients with brain involving cancers.

Correction to: Mesenchymal stem cells in the treatment of severe COVID-19

[This corrects the article DOI: 10.1186/s41231-021-00095-0.].

A Systems Approach to Brain Tumor Treatment

Brain tumors are among the most lethal tumors. Glioblastoma, the most frequent primary brain tumor in adults, has a median survival time of approximately 15 months after diagnosis or a five-year survival rate of 10%; the recurrence rate is nearly 90%. Unfortunately, this prognosis has not improved for several decades. The lack of progress in the treatment of brain tumors has been attributed to their high rate of primary therapy resistance. Challenges such as pronounced inter-patient variability, intratumoral heterogeneity, and drug delivery across the blood-brain barrier hinder progress. A comprehensive, multiscale understanding of the disease, from the molecular to the whole tumor level, is needed to address the intratumor heterogeneity resulting from the coexistence of a diversity of neoplastic and non-neoplastic cell types in the tumor tissue. By contrast, inter-patient variability must be addressed by subtyping brain tumors to stratify patients and identify the best-matched drug(s) and therapies for a particular patient or cohort of patients. Accomplishing these diverse tasks will require a new framework, one involving a systems perspective in assessing the immense complexity of brain tumors. This would in turn entail a shift in how clinical medicine interfaces with the rapidly advancing high-throughput (HTP) technologies that have enabled the omics-scale profiling of molecular features of brain tumors from the single-cell to the tissue level. However, several gaps must be closed before such a framework can fulfill the promise of precision and personalized medicine for brain tumors. Ultimately, the goal is to integrate seamlessly multiscale systems analyses of patient tumors and clinical medicine. Accomplishing this goal would facilitate the rational design of therapeutic strategies matched to the characteristics of patients and their tumors. Here, we discuss some of the technologies, methodologies, and computational tools that will facilitate the realization of this vision to practice.

ACTR-56. PHASE II TRIAL OF NILOTINIB IN PDGFR-ALPHA ENRICHED RECURRENT GLIOBLASTOMA

BACKGROUND

This phase II study was designed to determine the efficacy of nilotinib in a biomarker-selected population of recurrent glioblastoma (GBM), enriched for platelet-derived growth factor receptor-alpha (PDGFR-alpha) activation. Nilotinib is a multi-kinase inhibitor approved as treatment for Philadelphia-chromosome/Bcr-Abl chronic myelogenous leukemia. In addition to targeting Bcr-Abl tyrosine kinase, it also inhibits PDGFR-alpha signaling.

METHODS

Patients with recurrent GBM, with either PDGFR-alpha amplification or PDGFR-alpha overexpression by immunohistochemistry (IHC) were enrolled in a single-arm, single institution phase II study. Nilotinib was administered at 400 mg twice a day. The primary end point was progression-free survival at 6 months (PFS6). Secondary end points were safety, overall survival (OS) and Objective Response Rate (ORR).

RESULTS

34 patients were treated (22 IDH-wild type GBM, 2 IDH-mutant GBM, 10 GBM NOS). 26 were male and 8 were female. Median age was 55.5 (range 22–78 years). Four patients had PDGFR-alpha amplification, and 30 had overexpression by IHC. Median lines of prior therapy were 1 (range 1–7). 6/34 patients (18%) experienced related adverse events grade ≥ 3. There were no grade 5 events. The PFS6 was 9% (3/34), and PFS12 was 6% (2/34). Median PFS was 1.3 months and the median OS was 6.6 months. Best response was stable disease (SD) for 8 patients and complete response (CR) for one patient. ORR was 1/34 patients (3%). The patient with a CR was IDH-wild type, unmethylated, had PDGFR-alpha overexpression by IHC, and had a durable response > 5 years.

CONCLUSION

Nilotinib had limited activity in recurrent GBM enriched for PDGFR-alpha, although there were a small number of durable responders. Further molecular characterization is warranted to determine additional biomarkers of response that could be used to select patients that may benefit from nilotinib.

MNGI-05. COMBINED MULTIMODAL TREATMENT REGIMEN IN RECURRENT MENINGIOMAS

Meningiomas are the most common primary brain tumor, subsequent tumor progression can be problematic for surgical treatment options based upon location. Currently there is limited activity of various single agent medical therapies. We evaluated a combined treatment modality in recurrent Meningiomas. Patients were consented to NOC study protocol JWCI-17–0401 in this retrospective analysis. Treatment consisted of combination Octreotide LAR, Everolimus, Hydroxyurea, and Mifepristone. Patient characteristics in the combined treatment meningioma group (n=12) had a median age 60, 50% male, 47% WHO grade I, 37% WHO grade II, 11% WHO grade III, 67% skull base location, median number of recurrences is 2.2, with median number of surgeries of 1.7. Total comparison meningioma patients (n=19) with median age 62, 42% male, 42% WHO grade I, 50% WHO grade II, 17% WHO grade III, 58% skull base location, median number of recurrences is 2.2, with median number of surgeries of 2.2. Median PFS in recurrence prior to initiation of multimodal combined therapy, mPFS=283 days. Median PFS with subsequent multimodal combined therapy, mPFS=318 days. Multimodal therapy may prolong mPFS in recurrent meningiomas. Our pilot data supports further clinical trials in combined multimodal treatments.

RBTT-01. A PHASE 2 TRIAL WITH ABI-009 (NAB-SIROLIMUS) AS SINGLE-AGENT AND COMBINATIONS IN RECURRENT HIGH-GRADE GLIOMA (rHGG) AND IN NEWLY DIAGNOSED GLIOBLASTOMA (ndGBM)

BACKGROUND

The mTOR pathway is frequently activated in patients with GBM and is associated with reduced survival, making this pathway a promising target. However, mTOR inhibitors, including everolimus and temsirolimus, have poor brain penetration, limiting their potential use for GBM. ABI-009 is a novel albumin-bound mTOR inhibitor that has a distinct PK profile and biodistribution, including CNS penetration. The goal of this prospective, multi-cohort open-label phase 2 study is to evaluate the efficacy and safety of ABI-009 monotherapy and combination therapy in rHGG and ndGBM.

METHODS

Eligible patients are ≥18 years old, KPS score ≥70, and have histologically confirmed rHGG or ndGBM. Arm A has 5 cohorts in patients with rHGG, naïve to mTOR inhibitors: 1) ABI-009 single agent IV 100 mg/m2; 2–5) ABI-009 60mg/m2 plus TMZ 50mg/m2 or BEV 5mg/kg or marizomib 0.8mg/m2 or CCNU 90mg/m2. In Arm B for patients with ndGBM, ABI-009 100mg/m2 is given weekly for 4 weeks (Induction) after surgery, followed by ABI-009 at 60mg/m2 plus RT/TMZ. Up to 19 patients per cohort will be enrolled: initial 9 patients with a stopping rule that only if there are ≥2 responses will the study proceed to further enrollment of the next 10 patients (Simon’s 2-stage design). Treatment will continue until disease progression or unacceptable toxicity. The primary endpoint for all cohorts is overall response rate per RANO criteria; secondary endpoints are median PFS and OS, 6-month and 12-month PFS, 12-month OS, and safety. This study is open and actively enrolling patients. The anticipated enrollment period is 24 months. NCT03463265

Analysis of cell-free circulating tumor DNA in 419 patients with glioblastoma and other primary brain tumors

Aim:

Genomically matched trials in primary brain tumors (PBTs) require recent tumor sequencing. We evaluated whether circulating tumor DNA (ctDNA) could facilitate genomic interrogation in these patients.

Methods:

Data from 419 PBT patients tested clinically with a ctDNA NGS panel at a CLIA-certified laboratory were analyzed.

Results:

A total of 211 patients (50%) had ≥1 somatic alteration detected. Detection was highest in meningioma (59%) and gliobastoma (55%). Single nucleotide variants were detected in 61 genes, with amplifications detected in ERBB2, MET, EGFR and others.

Conclusion:

Contrary to previous studies with very low yields, we found half of PBT patients had detectable ctDNA with genomically targetable off-label or clinical trial options for almost 50%. For those PBT patients with detectable ctDNA, plasma cfDNA genomic analysis is a clinically viable option for identifying genomically driven therapy options.

Pritumumab, the first therapeutic antibody for glioma patients

Immunotherapy is now at the forefront of cancer therapeutic development. Gliomas are a particularly aggressive form of brain cancer for which immunotherapy may hold promise. Pritumumab (also known in the literature as CLNH11, CLN-IgG, and ACA-11) was the first monoclonal antibody tested in cancer patients. Pritumumab is a natural human monoclonal antibody developed from a B lymphocyte isolated from a regional draining lymph node of a patient with cervical carcinoma. The antibody binds ecto-domain vimentin on the surface of cancer cells. Pritumumab was originally tested in clinical trials with brain cancer patients in Japan where it demonstrated therapeutic benefit. It was reported to be a safe and effective therapy for brain cancer patients at doses 5-10 fold less than currently approved antibodies. Phase I dose escalation clinical trials are now being planned with pritumumab for the near future. Here we review data on the development and characterization of pritumumab, and review clinical trails data assessing immunotherapeutic effects of pritumumab for glioma patients.

Multi-platform molecular profiling of a large cohort of glioblastomas reveals potential therapeutic strategies

Glioblastomas (GBM) are the most aggressive and prevalent form of gliomas with abysmal prognosis and limited treatment options. We analyzed clinically relevant molecular aberrations suggestive of response to therapies in 1035 GBM tumors. Our analysis revealed mutations in 39 genes of 48 tested. IHC revealed expression of PD-L1 in 19% and PD-1 in 46%. MGMT-methylation was seen in 43%, EGFRvIII in 19% and 1p19q co-deletion in 2%. TP53 mutation was associated with concurrent mutations, while IDH1 mutation was associated with MGMT-methylation and TP53 mutation and was mutually exclusive of EGFRvIII mutation. Distinct biomarker profiles were seen in GBM compared with WHO grade III astrocytoma, suggesting different biology and potentially different treatment approaches. Analysis of 17 metachronous paired tumors showed frequent biomarker changes, including MGMT-methylation and EGFR aberrations, indicating the need for a re-biopsy for tumor profiling to direct subsequent therapy. MGMT-methylation, PR and TOPO1 appeared as significant prognostic markers in sub-cohorts of GBM defined by age. The current study represents the largest biomarker study on clinical GBM tumors using multiple technologies to detect gene mutation, amplification, protein expression and promoter methylation. These data will inform planning for future personalized biomarker-based clinical trials and identifying effective treatments based on tumor biomarkers.

Pritumumab binding to glioma cells induces ADCC and inhibits tumor growth

e14004

Background: Pritumumab is a natural human IgG1 kappa antibody originally isolated from a regional draining lymph node of a patient with cervical carcinoma. This antibody binds ectodomain vimentin on the surface of tumor cells and has demonstrated some benefit to glioblastoma patients in limited clinical trials. We wanted to determine if pritumumab inhibits glioma growth in vivo and if binding to glioma cells induces cell-mediated immunity. Methods: Pritumumab was used in flow cytometry experiments with several glioma cell lines and patient-derived neurosphere lines. Antibody-dependent cell-mediated cytotoxicity (ADCC) reporter assay was used with glioma target cells. Xenograft studies were performed in mice with and without intact B- and NK- cells. Results: We performed flow cytometry using pritumumab antibody and demonstrate binding of pritumumab to the surface of glioma cells and patient-derived glioma initiating cells. We observed significant induction of ADCC by pritumumab binding to glioma cells. Xenograft studies demonstrated pritumumab was effective in preventing tumor growth in nude mice but not in SCID mice. Intact cell-mediated immunity was necessary for pritumumab’s anti-tumor effect. Analysis of a blood brain barrier model showed significant binding of pritumumab in brain tumor areas and minimal distribution in normal brain tissues suggesting the antibody can cross the blood brain barrier. Conclusions: Our data demonstratepritumumab binds glioma cells in vitro and can induce ADCC. In addition, pritumumab can limit the growth of xenograft glioma tumors in vivo only in the presence of intact cell-mediated immunity. Together these data suggest pritumumab is suitable for development as an anti-tumor therapeutic.

Retrospective analysis of safety and feasibility of a 3 days on/11 days off temozolomide dosing regimen in recurrent adult malignant gliomas

AIMS

We report the safety and feasibility of a 3 days on/11 days off temozolomide regimen for the treatment of recurrent malignant gliomas.

PATIENTS & METHODS

Fifteen adult patients were treated; 14 were treated with 300 mg/m(2) and one treated with 250 mg/m(2).

RESULTS

We reviewed the toxicity, progression-free survival (PFS), overall survival and objective response rate. Two patients (13%) experienced grade 3 nausea/vomiting and six patients (40%) experienced grade 3 lymphopenia. Dose reduction and treatment delay occurred in eight (53%) cases. One patient discontinued treatment due to uncontrolled nausea/vomiting. Median PFS for glioblastoma patients was 4.1 months and 6-month PFS was 25%. Twelve patients exhibited stable disease (86%), one patient (7%) had progressive disease and one patient (7%) showed a partial response.

CONCLUSION

The '3 on/11 off' temozolomide regimen for recurrent high-grade gliomas was tolerable and warrants further study in a larger, prospective study.

Hyaluronan expression in primary and secondary brain tumors

BACKGROUND

Collectively, primary and secondary brain tumors represent a major public health challenge. Glioblastoma (GBM) is the most common primary brain tumor in adults and is associated with a dismal 5-year survival of only 10%. Breast cancer causes secondary tumors; it occurs in 200,000 patients yearly and 30% of these individuals develop brain metastases which also lead to a very poor prognosis. GBM and primary breast tumors are known to express hyaluronan (HA) which may serve as a therapeutic target.

METHODS

For the present study we had two aims: (I) to identify suitable preclinical models for HA in GBM by examining HA expression in human GBM cell lines implanted orthotopically in mice; and (II) to determine whether breast cancer brain metastases in human patients express HA similar to the primary tumor. Forty human surgical samples of primary breast tumors and breast cancer brain metastases were processed and stained for HA. Athymic nu/nu mice were orthotopically implanted with one of 15 GBM lines and after tumors were established, quantitative immunohistochemistry determined whether.

RESULTS

HA was expressed. All GBM cell lines and patient-derived orthotopic tumors did express HA, with 3 primary human lines expressing the highest staining intensity, above that of normal brain. All 40 human primary breast tumors and brain metastases examined also contained HA, though staining intensity was highly variable.

CONCLUSIONS

Our data support the use of specific patient-derived GBM cell lines in nu/nu mice for preclinical studies on HA-targeting therapies. Additionally, our research provides a basis for the assessment of HA expression and HA-targeting therapeutic agents for the treatment of breast cancer brain metastases.

Abstract 4652: Cerebrospinal fluid pharmacokinetics and pharmacodynamics following high-dose erlotinib treatment in brain cancer patients

Patients with non-small cell lung cancer (NSCLC) who develop leptomeningeal metastases show significant clinical improvement following high-dose gefitinib therapy. Based on this data, we aimed to explore the effect of high-dose erlotinib on clinical response and CNS penetration in primary or metastatic CNS cancer.

We selected patients who had received prior therapy for either primary glioma or for NSCLC with metastases to the brain and treated them with an alternate dosing regimen of erlotinib. Blood and cerebrospinal fluid (CSF) samples were collected at various time points to assess levels of erlotinib. We found that CSF concentrations of erlotinib were generally 2% that of plasma concentrations. Among the five patients examined, CSF concentrations of erlotinib reached up to 131 nM when high doses were administered at 600 to 1200 mg every four to six days. Additionally, drug clearance was decreased with an increased dosing regimen in one of the patients. In one patient, the area under the curve (AUC) estimations showed a 24% increase in the CSF versus only a 2% increase in the plasma following an increase from 150 mg to 600 mg of erlotinib. Moreover, longitudinal CSF samples were evaluated for expression and activation of EGFR as well as various other receptor tyrosine kinases, such as ErbB2, ErbB3, cMET and IGF1R, using the highly sensitive multiplexed immunoassay CEER© platform. The latter provides insight into the molecular makeup of the CNS cancer throughout the therapeutic regimen.

Our clinical data on patients receiving erlotinib therapy for primary and metastatic CNS disease suggests that increased dosing of erlotinib, administered as a pulse dose every four to six days leads to increased CSF drug concentrations. In spite of the variations seen among different patients, we conclude that higher erlotinib dosing regimens can provide enhanced CNS penetration that may prove to be more effective in primary and metastatic CNS cancers especially when coupled with real-time molecular monitoring of the disease to help guide the clinician during the course of treatment.

Citation Format: Sandra Pastorino, Sandeep C. Pingle, Emma Langley, Phillip Kim, Tiffany Juarez, Pengfei Jiang, Christopher Tucker, Txheng Yang, Marlon Saria, Sharat Singh, Santosh Kesari. Cerebrospinal fluid pharmacokinetics and pharmacodynamics following high-dose erlotinib treatment in brain cancer patients. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4652. doi:10.1158/1538-7445.AM2014-4652

Prostate specific membrane antigen (PSMA) expression in primary gliomas and breast cancer brain metastases

Background

Primary and secondary brain cancers are highly treatment resistant, and their marked angiogenesis attracts interest as a potential therapeutic target. Recent observations reveal that the microvascular endothelium of primary high-grade gliomas expresses prostate specific membrane antigen (PSMA). Breast cancers express PSMA and they frequently form secondary brain tumors. Hence we report here our pilot study addressing the feasibility of PSMA targeting in brain and metastatic breast tumors, by examining PSMA levels in all glioma grades (19 patients) and in breast cancer brain metastases (5 patients).

Methods

Tumor specimens were acquired from archival material and normal brain tissues from autopsies. Tissue were stained and probed for PSMA, and the expression levels imaged and quantified using automated hardware and software. PSMA staining intensities of glioma subtypes, breast tumors, and breast tumor brain metastases were compared statistically versus normals.

Results

Normal brain microvessels (4 autopsies) did not stain for PSMA, while a small proportion (<5%) of healthy neurons stained, and were surrounded by an intact blood brain barrier. Tumor microvessels of the highly angiogenic grade IV gliomas showed intense PSMA staining which varied between patients and was significantly higher (p < 0.05) than normal brain. Grade I gliomas showed moderate vessel staining, while grade II and III gliomas had no vessel staining, but a few (<2%) of the tumor cells stained. Both primary breast cancer tissues and the associated brain metastases exhibited vascular PSMA staining, although the intensity of staining was generally less for the metastatic lesions.

Conclusions

Our results align with and extend previous data showing PSMA expression in blood vessels of gliomas and breast cancer brain metastases. These results provide a rationale for more comprehensive studies to explore PSMA targeted agents for treating secondary brain tumors with PSMA expressing vasculature. Moreover, given that PSMA participates in angiogenesis, cell signaling, tumor survival, and invasion, characterizing its expression may help guide later investigations of the poorly understood process of low grade glioma progression to glioblastoma.

A selective role of NKG2D in inflammatory and autoimmune diseases

The NKG2D activating receptor has been implicated in numerous autoimmune diseases. We tested the role of NKG2D in models of autoimmunity and inflammation using NKG2D knockout mice and antibody blockade experiments. The severity of experimental autoimmune encephalitis (EAE) was decreased in NKG2D-deficient mice when the disease was induced with a limiting antigen dose, but unchanged with an optimal antigen dose. Surprisingly, however, NKG2D deficiency had no detectable effect in several other models, including two models of type 1 diabetes, and a model of intestinal inflammation induced by poly(I:C). NKG2D antibody blockade in normal mice also failed to inhibit disease in the NOD diabetes model or the intestinal inflammation model. Published evidence using NKG2D knockout mice demonstrated a role for NKG2D in mouse models of atherosclerosis and liver inflammation, as well as in chronic obstructive pulmonary disease. Therefore, our results suggest that NKG2D plays selective roles in inflammatory diseases.

Households contaminated by environmental tobacco smoke: sources of infant exposures

OBJECTIVES

To examine (1) whether dust and surfaces in households of smokers are contaminated with environmental tobacco smoke (ETS); (2) whether smoking parents can protect their infants by smoking outside and away from the infant; and (3) whether contaminated dust, surfaces, and air contribute to ETS exposure in infants.

DESIGN

Quasi-experiment comparing three types of households with infants: (1) non-smokers who believe they have protected their children from ETS; (2) smokers who believe they have protected their children from ETS; (3) smokers who expose their children to ETS.

SETTING

Homes of smokers and non-smokers.

PARTICIPANTS

Smoking and non-smoking mothers and their infants < or = 1 year.

MAIN OUTCOME MEASURES

ETS contamination as measured by nicotine in household dust, indoor air, and household surfaces. ETS exposure as measured by cotinine levels in infant urine.

RESULTS

ETS contamination and ETS exposure were 5-7 times higher in households of smokers trying to protect their infants by smoking outdoors than in households of non-smokers. ETS contamination and exposure were 3-8 times higher in households of smokers who exposed their infants to ETS by smoking indoors than in households of smokers trying to protect their children by smoking outdoors.

CONCLUSIONS

Dust and surfaces in homes of smokers are contaminated with ETS. Infants of smokers are at risk of ETS exposure in their homes through dust, surfaces, and air. Smoking outside the home and away from the infant reduces but does not completely protect a smoker's home from ETS contamination and a smoker's infant from ETS exposure.

Comparative analysis of human NK cell activation induced by NKG2D and natural cytotoxicity receptors

NKG2D and natural cytotoxicity receptors (NCR) are essential recognition structures that mediate NK cell activation. NKG2D and NCR signaling is achieved through membrane association with signaling adaptors. The adaptors that associate with NCR--such as CD3 zeta, FcR gamma and KARAP/DAP12--bear intracytoplasmic immunoreceptor tyrosine-based activation motifs that activate Syk protein tyrosine kinases. Human NKG2D associates with the DAP10 transmembrane adaptor, which bears a YxxM motif and activates the phosphatidylinositol 3-kinase pathway. In the mouse, a short NKG2D-S isoform, generated by Nkg2d alternative splicing, can associate with either DAP10 or KARAP/DAP12. Here, we report that neither short human NKG2D alternative transcripts nor NKG2D association with KARAP/DAP12 was detected in activated human NK cells. Despite these results, NK cell triggering by both recombinant soluble NKG2D ligands (MICA and ULBP-1) and anti-NCR cross-linking antibodies induced similar CD25 expression, NK cell proliferation and cytokine production. In contrast, NKG2D triggering by anti-NKG2D antibodies did not lead to any detectable activation signals. These data thus show that target recognition via NKG2D or NCR triggers all aspects of NK activation, and pave the way for further dissection of the signaling pathways induced by NK cell recognition of ULBP-1 and MICA.

Households contaminated by environmental tobacco smoke: sources of infant exposures

OBJECTIVES

To examine (1) whether dust and surfaces in households of smokers are contaminated with environmental tobacco smoke (ETS); (2) whether smoking parents can protect their infants by smoking outside and away from the infant; and (3) whether contaminated dust, surfaces, and air contribute to ETS exposure in infants.

DESIGN

Quasi-experiment comparing three types of households with infants: (1) non-smokers who believe they have protected their children from ETS; (2) smokers who believe they have protected their children from ETS; (3) smokers who expose their children to ETS.

SETTING

Homes of smokers and non-smokers.

PARTICIPANTS

Smoking and non-smoking mothers and their infants < or = 1 year.

MAIN OUTCOME MEASURES

ETS contamination as measured by nicotine in household dust, indoor air, and household surfaces. ETS exposure as measured by cotinine levels in infant urine.

RESULTS

ETS contamination and ETS exposure were 5-7 times higher in households of smokers trying to protect their infants by smoking outdoors than in households of non-smokers. ETS contamination and exposure were 3-8 times higher in households of smokers who exposed their infants to ETS by smoking indoors than in households of smokers trying to protect their children by smoking outdoors.

CONCLUSIONS

Dust and surfaces in homes of smokers are contaminated with ETS. Infants of smokers are at risk of ETS exposure in their homes through dust, surfaces, and air. Smoking outside the home and away from the infant reduces but does not completely protect a smoker's home from ETS contamination and a smoker's infant from ETS exposure.

A double-blind study of topically applied 5% amlexanox in the treatment of aphthous ulcers

A double-blind trial of amlexanox (C16H14N2O4) was carried out in 32 patients with recurrent oral aphthous ulcerations. During the treatment period, which lasted for 3 days, patients received either placebo topical paste or 5% amlexanox paste. The paste was applied by the investigator twice per day for 3 days and once on the fourth day. Efficacy was assessed by the following parameters: 1) pain measured by the patients marking a 15-cm line between poles connoting no pain versus severe pain; 2) erythema evaluated by the investigator on a four-point scale ranging from none to strong; 3) size determined by investigator measurement of the perpendicular dimensions of the ulcer; and 4) an investigator's improvement scale consisting of six rank-ordered points from -1 for worsening of the ulcer with respect to previously described criteria to +4 when the ulcer had healed completely. All evaluations were based on a comparison with the day 1 visit of the patient. Outcomes for patients receiving the active ingredient were superior on all four criteria of effectiveness. Group differences for all criteria but pain reduction were statistically significant (P < .05). No side effects were reported. It was concluded that amlexanox is effective in reducing aphthous ulcer erythema, pain, and lesional size.

Investigation of evidence for anticipatory postural adjustments in seated subjects who performed a reaching task

The paradigm for study of anticipatory postural adjustments permits investigation of the coordination of postural and voluntary components of functional movement. The purpose of this study was to investigate whether there were anticipatory postural adjustments for voluntary movement in seated subjects under clinically relevant conditions. Eight neurologically normal subjects performed a reaching task to a target placed at shoulder height, 45 degrees to the right of midline. Onsets and magnitudes of lateral and fore-aft reactive forces associated with the movement and of electromyographic (EMG) activity of the ipsilateral deltoid and external abdominal oblique and contralateral paraspinal muscles were monitored. Conditions of trunk support, reach speed, and distance reached were manipulated. Onsets of deltoid muscle EMG activity preceded onsets of postural muscle (external oblique and paraspinal) EMG activity in 70% of all trials for seated subjects in contrast to reports of EMG activity onset in the postural muscles in advance of the prime mover in standing subjects who performed a similar task. The role of the trunk musculature and the significance of reactive forces in advance of hand movement were equivocal. This study has implications for evaluation of postural instability in persons unable to stand for testing.