CNS Response Research Articles

Multivariate analysis of the systemic response to auditory stimulation: An integrative approach.

What is the central question of this study? Auditory stimulation produces a response in different physiological systems: cardiac, peripheral blood flow, electrodermal, cortical and peripheral haemodynamic responses and auditory event-related potentials. Do all these subsystems covary when responding to auditory stimulation, suggesting a unified locus of control, or do they not covary, suggesting independent loci of control for these physiological responses? What is the main finding and its importance? Auditory sensory gating reached a fixed level of neural activity independently of the intensity of auditory stimulation. The use of multivariate techniques revealed the presence of different regulatory mechanisms for the different physiologically recorded signals. We studied the effects of an increasing amplitude of auditory stimulation on a variety of autonomic and CNS responses and their possible interdependence. The subjects were stimulated with an increasing amplitude of auditory tones while the auditory event-related potentials (ERPs), the cortical and extracerebral functional near-infrared spectroscopy (fNIRS) signal of standard and short separation channel recordings, the peripheral pulse measured by photoplethysmography, heart rate and electrodermal responses were recorded. Trials with eight tones of equal amplitude were presented. The results showed a parallel increase of activity in ERPs, fNIRS and peripheral responses with the increase in intensity of auditory stimulation. The ERPs, measured as peak-to-peak N1-P2, showed an increase in amplitude with auditory stimulation and a high attenuation from the first presentation with respect to the second to eighth presentations. Peripheral signals and standard and short channel fNIRS responses showed a decrease in amplitude in the high-intensity auditory stimulation conditions. Principal components analysis showed independent sources of variance for the recorded signals, suggesting independent control of the recorded physiological responses. The present results suggest a complex response associated to the increase of auditory stimulation with a fixed amplitude for ERPs, and a decrease in the peripheral and cortical haemodynamic response, possibly mediated by activation of the sympathetic nervous system, constituting a defensive reflex to excessive auditory stimulation.

P34.10 Transformation to Small Cell Lung Cancer from an Adenocarcionma EGFR+ as Resistance Mechanism. Utility of Liquid Biopsy in Treatment Selection

Tyrosine kinase inhibitors (TKIs) have been shown to be effective in advanced lung cancer with mutation of the EGFR gene. Several mechanisms of resistance to TKIs have been identified, such as: point mutation of the EGFR T790M within exon 205.6, amplification of the MET and Her2 gene, secondary mutations in BRAF-12 and very rarely the histological transformation to small cell lung cancer (SCLC). Case Report CLINICAL CASE : 51-year-old, former tobacco user, diagnosed in 2013 with left locally advanced lung adenocarcinoma, Stage IIIB, EGFR mutated (L858R) by liquid biopsy (LB) because the lake of histological material was not enough to study EGFR in tumoral tissue. Initially received gefitinib 250 mg/day. After 4 years she progressed in 2017, with increase of lung tumor mass with bone compromise. The histological diagnose of lesion showed: Poorly differentiated lung carcinoma with features of SCLC confirmed by Immunohistochemistry, a 2nd LB was performed and informed EGFR L858R mutation in circulating DNA (cDNA). The therapeutic plan was Radiation therapy in rib cage and 6 cycles of chemotherapy platin based plus etoposide, after complete treatment response assessment (RA) showed stable disease. In March 2019 a 3rd LB was performed, an EGFR L858R + in cDNA was still present; so patient restart Gefitinib. A 6-month tomography control informed stable lung images with new liver metastases and a brain CT scan performed because neurological symptoms showed a right frontal cortical lesion of 16 mm x 19 mm. She received whole brain radiotherapy. She archived complete response in CNS by images and significant clinical improvement, but progression, with multiples nodule in the lung and liver . The new liver biopsy demonstrated an infiltration of SCLC, and a 4th LB showed EGFR + L858R mutation. Based in this information it was decided to continue with gefitinib and start a second line chemotherapy, with taxanes, in a concurrent way. At the moment of this report, the patient is still alive with stable disease, after three cycles of chemotherapy, whitout any severe adverse effects, except mild diarrhea and dermatitis. LB has demonstrated in this patient the coexistence of L858 Mutation in blood and SCLC in tumor tissue. The transformation to SCLC in histological tissue biopsy is a very rare mechanism of resistance to TKIs, about 3 % of the cases of the patients with EGFR mutations. LB allows us to select the best treatment for this patient and could detect the absence of other mechanism of resistance, like mutation of the EGFR T790M. At the moment of the presentation of this abstract, there are very few cases and reports about the right treatment of the patient with this uncommon condition in the literature. One of this reports describe a patient with the T 790 M in LB and a transformation to SCLC in tumor tissue, treated with osimertinib plus chemotherapy. A larger number of patients could provide a strong evidence on this issue.

COMMUNICATION BETWEEN GUT MICROBES AND BRAIN

Clinical and preclinical studies have shown that there is bidirectional interaction between brain and gut microbiome. Gut microbes communicate to CNS through at least 3 channels, which involves nervous, endocrine, and immune signaling mechanisms. Gut bacteria also influence the development of CNS and stress responses. Gut bacteria can also provide protection from central effects of infection and inflammation as well as modulate normal behavioral responses. The vagus nerve has also emerged as an important means of communicating signals from gut microbes to CNS. A systems biological model is proposed that posits circular communication between brain, gut and gut microbes and in which disturbance at any level can dysregulate whole circuit.

Time-of-Day-Dependent Gating of the Liver-Spinal Axis Initiates an Anti-Inflammatory Reflex in the Rat

The autonomic nervous system (ANS) modulates the immune response through the engagement of an anti-inflammatory reflex. There is controversy regarding which efferent branch of the ANS, sympathetic or parasympathetic, downregulates the intensity of the inflammatory response. Furthermore, how information about the immune status of the body reaches the CNS to engage this reflex remains unclear. The present study demonstrates the existence of a liver-spinal axis that conveys early circulating inflammatory information to the CNS in response to lipopolysaccharide (LPS) and serves as the afferent arm of a sympathetic anti-inflammatory reflex. Furthermore, brainstem and spinal cord visceral sensory neurons show a time-of-day-dependent sensitivity to the incoming inflammatory information, in particular, prostaglandins (PG). Consequentially, the liver-spinal axis promotes the retention of tumor necrosis factor α (TNFα) in the liver and spleen during the resting period, resulting in low plasmatic TNFα levels. Consistently, low sensitivity for LPS during the active period promotes the release of TNFα from the organs into the circulation, resulting in high plasmatic TNFα levels. The present novel findings illustrate how the time-of-day-dependent activation of the liver-spinal axis contributes to the daily fluctuations of the inflammatory response.

The different central nervous system efficacy among gefitinib, erlotinib and afatinib in patients with epidermal growth factor receptor mutation-positive non-small cell lung cancer.

BackgroundBrain metastasis is common in non-small cell lung cancer (NSCLC) and has an even higher incidence in epidermal growth factor receptor (EGFR)-mutant cancers. Although EGFR tyrosine kinase inhibitors (TKIs) are effective against brain metastases, it is unknown which first- or second-generation EGFR TKI is most effective.MethodsPatients treated with first-line gefitinib, erlotinib, or afatinib for advanced EGFR-mutant NSCLC were included. The efficacy against brain metastasis was evaluated by comparing the response rates of measurable and non-irradiated brain metastases, central nervous system progression-free survival (CNS-PFS), and the cumulative incidence of CNS failure.ResultsAmong the 559 patients who received EGFR-TKIs (gefitinib, n=299; erlotinib, n=93; afatinib, n=167), 198 had initial brain metastasis before starting EGFR-TKIs. The CNS response rates of gefitinib, erlotinib, and afatinib were 64.7%, 68.2%, and 72.9%, respectively (P=0.78). In the overall study population, irrespective of initial CNS metastasis, the median CNS-PFS was 17.3 months for gefitinib, 12.4 months for erlotinib, and 23.3 months for afatinib (P<0.001). In multivariate analysis for CNS-PFS, the hazard ratio (HR) of afatinib was 0.63 (95% CI, 0.47–0.83) compared with gefitinib or erlotinib. In the competing risk analysis for cumulative incidence of CNS failure, afatinib showed a lower cumulative incidence of CNS failure compared with gefitinib or erlotinib after adjusting for both EGFR mutation type and preexisting CNS metastases (HR 0.51, 95% CI, 0.34–0.75, P=0.0007).ConclusionsThrough there are some limitation as a retrospective study, afatinib showed similar CNS response rates, superior CNS-PFS and cumulative incidence of CNS failure, compared with gefitinib or erlotinib

Treatment response of CNS high-grade neuroepithelial tumors with MN1 alteration.

Central nervous system high-grade neuroepithelial tumor with MN1 alteration (CNS HGNET-MN1) is a rare recently described entity. Fourteen CNS HGNET-MN1 patients were identified using genome-wide methylation arrays/RT-PCR across seven institutions. All patients had surgery (gross total resection: 10; subtotal resection: four) as initial management followed by observation alone in three patients, followed by radiotherapy in eight patients (focal: five; craniospinal: two; CyberKnife: one) and systemic chemotherapy in three patients. Seven patients relapsed; five local and two metastatic, despite adjuvant radiotherapy, of which three died. Treatment of CNS HGNET-MN1 remains a major treatment challenge despite aggressive surgical resections and upfront radiotherapy, warranting new approaches to this rare malignancy.

CNS Metastases in Patients With MET Exon 14-Altered Lung Cancers and Outcomes With Crizotinib.

Although MET exon 14 (METex14)-altered lung cancers were first identified more than a decade and a half ago, the frequency of CNS metastatic disease remains poorly defined. Furthermore, the seminal trial of crizotinib in these patients (PROFILE 1001) did not report patterns of CNS response or progression. Patients with pathologically confirmed, advanced non-small-cell lung cancers (NSCLC) harboring a METex14 alteration by targeted DNA/RNA sequencing were studied. The incidence of brain metastases and the outcomes of MET inhibition with crizotinib were analyzed. Eighty-three patients with METex14-altered metastatic NSCLC were identified. The incidence of CNS metastases at diagnosis was 17% (95% CI, 10% to 27%). The lifetime incidence was 36% (95% CI, 26% to 47%); 83% of patients had parenchymal disease, and 17% had leptomeningeal disease. The probability of having brain metastasis at 1, 2, and 3 years was 24%, 35%, and 38%, respectively. Fifty-four patients received crizotinib. The median time to radiologic CNS progression was 5.8 months (range, 3.7-20.0 months). Patterns of crizotinib progression were as follows: intracranial only in 10% of patients, intracranial and extracranial in 12%, and extracranial only in 78%. In patients with brain metastases before treatment, the median time on crizotinib was 7.5 months (range, 7.2-11.7 months). CNS metastases, including leptomeningeal disease, occurred in more than a third of patients with METex14-altered lung cancers. In crizotinib-treated patients with or without CNS metastases, CNS failure was seen in less than a quarter of patients on progression.

Lapatinib plus Capecitabine versus Trastuzumab plus Capecitabine in the Treatment of Human Epidermal Growth Factor Receptor 2-positive Metastatic Breast Cancer with Central Nervous System Metastases for Patients Currently or Previously Treated with Trastuzumab (LANTERN): a Phase II Randomised Trial

AimsBrain (central nervous system; CNS) metastases occur in 30–50% of patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC). A substantive evidence base for treatment is lacking, but activity with lapatinib plus capecitabine (lap-cap) has been reported. We compared lap-cap with trastuzumab plus capecitabine (tras-cap) in patients with HER2-positive MBC with CNS metastases previously treated with trastuzumab. Materials and methodsThis open-label randomised phase II screening trial aimed to randomise 130 participants over 2 years to receive lap-cap or tras-cap. Eligible patients had HER2-positive MBC with newly diagnosed or recently progressed CNS metastases; previous, or current, treatment included: trastuzumab, a taxane or anthracycline and recent completion of local cranial therapy. The primary end point was time to progression of CNS metastases within the 24-week trial period. Secondary objectives included CNS response rate, progression-free survival, steroid use for CNS symptoms and feasibility of recruitment to a large phase III trial. ResultsBetween September 2011 and October 2013, 30 participants were randomised, 16 to lap-cap and 14 to tras-cap. Recruitment to a large phase III trial was determined not to be feasible. At 24 weeks, CNS disease progression was 41.8% (95% confidence interval 16.1–67.5%) in lap-cap and 41.2% (95% confidence interval 12.8–69.6%) in tras-cap arms; progression-free survival was 44.4% (95% confidence interval 18.1–70.8%) in lap-cap and 50.0% (95% confidence interval 20.9–79.1%) in tras-cap arms. ConclusionPoor recruitment confirmed that a larger phase III trial would not be feasible and prohibited a preliminary evaluation of the superiority of lap-cap over tras-cap. Descriptive statistics are presented to inform the limited evidence base and future study design.

The application of electrophysiological methods to characterize AMPA receptors in dissociated adult rat and non-human primate cerebellar neurons for use in neuronal safety pharmacology assessments of the central nervous system

IntroductionPre-clinically, safety risk assessment of a drug is primarily tested in vivo using functional evaluation of adult animals while the mechanistic etiology of drug-induced CNS adverse effects is often uncharacterized. In vitro electrophysiology may provide a better understanding of drug effects without additional animal use. However, in vitro protocols are typically designed for using embryonic or juvenile animals. MethodsWe examined whether brain tissue isolated from adult rats (3–5 months old) and adult non-human primates (NHPs) (2–8 years old) can generate qualitatively equivalent readouts for electrophysiology to characterize AMPAR synaptic and single channel currents. We used a known positive AMPAR allosteric modulator (LY451395) to template a response profile and provide proof-of-concept data to assess responses of these native AMPARs in a drug context. ResultsBrain slices from adult animals provided a support to measure AMPAR-driven excitatory post-synaptic currents (EPSCs), and can be dissociated into primary neuronal cultures for AMPAR single channel characterization. Additionally, similarities and differences in AMPAR basal kinetics and responses to LY451395 were seen between the two animal species. DiscussionGlutamatergic synaptic activity and AMPAR biophysical properties in adult animals may be used to characterize test-article–mediated alterations in CNS responses. The use of older animals opens the possibility for in vivo test-article administration, either acutely or repeatedly, before in vitro electrophysiological assessment in order to reveal cumulative or delayed-onset effects, adding versatility to safety pharmacology assessment of the CNS.

Anti-PD-1 for patients with leptomeningeal metastasis from advanced solid tumors: Efficacy, safety, and biomarkers of response.

e14506 Background: Leptomeningeal metastasis (LMM) from solid tumors are rare and often refractory to standard therapies. Pembrolizumab (anti-PD-1) has efficacy in patients (pts) with brain metastases from ICI-responsive tumors, however pts with LMM are often excluded from ICI trials. We hypothesized that: 1. Pembrolizumab will lead to CNS response in LMM, and 2. Genomic/immunologic analyses on CSF could identify CNS biomarkers of response. Methods: We conducted an investigator-initiated open-label phase 2 trial of Pembrolizumab in pts with LMM from any solid tumor (NCT03091478). Eligible pts had: LMM on MRI ( &gt; 3mm lesion) or CSF cytology, ECOG PS ≤1, and were PD-naïve. Prior RT to LMM was allowed &gt; 3 months before study start or to non-target areas. Pembrolizumab was administered IV 200mg q3W until disease progression/unacceptable toxicity. The primary endpoint was CNS response after 12 weeks, defined as radiologic (RECIST 1.1)/cytologic/clinical response to therapy. Serial CSF samples were assessed by chromosomal copy number changes using a PCR-based approach (RealSeqS) to detect tumor-derived DNA (CSF-tDNA), and 16-color flow cytometry. Results: Thirteen of a planned 18 pts were treated 04/2017-12/2019, the study was closed early for low accrual. Median age was 58 years (22-79), 53% were female. Pts had breast carcinoma (38%, n = 5), NSCLC (23%, n = 3), high-grade glioma (23%, n = 3), HNSCC (8%, n = 1) and cutaneous squamous cell carcinoma (8%, n = 1). Median no. of prior therapies was 4 (0-8), 76% of pts had prior RT to LMM. CNS response was seen in 38% of pts (5/13: 2 = complete response (NSCLC; Squamous skin); 3 = stable disease (NSCLC, Glioma, HER2+BC) by RECIST 1.1. Treatment-related adverse events were seen in 31% (4/13) of pts, 15% (2/13) G3+ (fatigue = 1, infection = 1). CSF cytology was negative at ICI start in 6 cases, but positive by CSF-tDNA in 5/6 cases. In addition, CSF-tDNA levels can correlate with disease status. CSF flow cytometry demonstrated increase in CD45R0+ activated memory T-cells, and a shift from immature to antibody-secreting B-cells in both pts with CRs in LMM. Conclusions: Pembrolizumab was well-tolerated and demonstrated anti-tumor activity in pts with LMM in ICI-responsive tumors. Correlative analyses identified CSF-tDNA can potentially be used from diagnosis to longitudinally monitor LMM; and that T and B cell populations may be enriched in the CSF of pts whose LMM regressed. These findings support inclusion of pts with LMM in ICI studies and interrogation of CSF biomarkers. Clinical trial information: NCT03091478.

CD56bright/CD16bright NK-cell adoptive immunotherapy in patients with concurrent CNS disease and relapsed or refractory (R/R) AML.

3025 Background: Patients (pts) with R/R AML and concurrent CNS disease rarely respond to chemotherapy and have a dismal prognosis. Adoptive immunotherapy (AI) with haploidentical ex vivo-activated/expanded NK cells shows promise in R/R AML, but it is unknown whether the blood–brain barrier (BBB) represents an obstacle to this approach. Here we present data from 4 pts with CNS disease from a phase 1 study of 13 pts receiving NK AI for R/R AML (NCT02809092). Methods: Double bright (CD56bright/16bright) activated NK cells (DBNK) were expanded from haploidentical family donors on feeder cells expressing membrane-bound IL-21. DBNK were infused thrice weekly for six doses 3–7 days after fludarabine, cytarabine, and G-CSF (FLAG). Pts received doses ranging from 106 to 107 DBNK/kg/infusion. CNS responses at day 30 were assessed using Response Assessment in Neuro-Oncology criteria. RNA sequencing was used to compare gene expression in DBNK vs unexpanded NK cells. Results: Demographics of the 4 pts with CNS disease are shown (Table). All pts had received a prior stem cell transplant and were heavily pretreated (median 6 prior treatments), and 1 had primary refractory disease. All pts completed 6 NK-cell infusions without dose-limiting toxicities. No cytokine storm syndrome was reported. Other toxicities were manageable, including CNS hypertension symptoms. Imaging studies showed inflammation localized to disease sites. All 4 pts showed a response (Table), with complete, long-lasting resolution of CNS lesions documented in pts #1 &amp; #5, almost complete resolution of bone and nerve root leukemic infiltration in pt #4, and a 50% reduction of CNS chloromas in pt #6. Responses were durable, lasting up to 7 months. DBNK showed upregulation of homing receptors associated with CNS trafficking. Conclusions: Multiple infusions of ex vivo IL-21-expanded DBNK were tolerable and demonstrated unprecedented CNS responses in patients with R/R AML. These data support effectiveness of DBNK across the BBB. Clinical trial information: NCT02809092 . [Table: see text]

Beneficial Effects of Fingolimod on Social Interaction, CNS and Peripheral Immune Response in the BTBR Mouse Model of Autism

Autism Spectrum Disorders (ASD) are neurodevelopmental disorders characterized by social communication deficits and repetitive/stereotyped behaviours. We evaluated the effects of a chronic treatment with the immunomodulator drug Fingolimod (FTY720 – a non-selective Sphingosine 1-Phosphate Receptor ligand) in an ASD model, the BTBR T+tf/J (BTBR) mouse strain. In adult BTBR males, chronic FTY720 treatment (4 weeks) increased social and vocal response during a male–female interaction and hippocampal expression of BDNF and Neuregulin 1, two trophic factors reduced in BTBR when compared to control C57 mice. FTY720 also re-established the expression of IL-1β and MnSOD in the hippocampus, whereas it did not modify IL-6 mRNA content. In addition to its central effect, FTY720 modulated the activation state of peripheral macrophages in the BTBR model, both in basal conditions and after stimulation with an immune challenge. Furthermore, IL-6 mRNA colonic content of BTBR mice, reduced when compared with C57 mice, was normalized by chronic treatment with FTY720. Our study, while indicating FTY720 as a tool to attenuate relevant alterations of the BTBR neurobehavioural phenotype, emphasizes the importance of gut mucosal immune evaluation as an additional target that deserve to be investigated in preclinical studies of anti-inflammatory therapeutic approaches in ASD.

The Effects of Plyometric Training on Motor Skills of Top Volleyball Players / Efekti pliometrijskog treninga na motoričke sposobnosti vrhunskih odbojkaša

The plyometric method is ranked among the most commonly used methods for fitness volleyball training. It leads to the development of explosive strength and reactive velocity of the muscular system based on improving the CNS response and the power required to absorb the stress when landing. The study was of longitudinal type, involving two measurements, an initial measurement for all subjects to determine the initial level of motor ability, and a final measurement where the effects of the experimental program were studied after a programmed experimental process to develop specific motor skills of the analyzed sample of subjects. The entire study was conducted on a sample of 72 senior subjects, which were divided into two sub-samples, one sub-sample comprised of the experimental group and the other comprising the control group. The primary objective of the research was to test the influence and effect of special treatment of kinesiological activities based on plyometric exercises on the motor skills of the subjects.

Dual BRAF/MEK blockade restores CNS responses in BRAF-mutant Erdheim-Chester disease patients following BRAF inhibitor monotherapy.

BackgroundErdheim–Chester disease (ECD), a rare inflammatory myeloid neoplasm, is known to be fundamentally reliant on the constitutive activation of the MAPK signaling pathway in the majority of patients. Consequently, inhibition of the V600E-mutant BRAF kinase has proven to be a safe and efficacious long-term therapeutic strategy for BRAF-mutant ECD patients. Nevertheless, in a subset of patients with CNS disease, the efficacy of long-term treatment may diminish, facilitating suboptimal responses or disease progression.MethodsWe retrospectively describe 3 BRAF-mutant ECD patients whose treatment with Vemurafenib was upgraded to Vemurafenib/Cobimetinib due to either disease progression, insufficient response, or unacceptable toxicity. CNS response to therapy was evaluated using magnetic resonance imaging (MRI) and extra-cranial disease was monitored using 18F-fludeoxyglucose positron emission tomography/computed tomography (PET/CT).ResultsThree patients with a mean age of 52.6 years were treated with Vemurafenib for a mean duration of 26.6 months (range: 6–52). Monotherapies were upgraded to Vemurafenib/Cobimetinib dual therapy. The combination therapy was administered for a mean duration of 21 months (range: 19–23). All patients exhibited clinical and neurological improvement. Regression of lesions on MRI was noted in 2 patients. Both patients characterized by a PET-avid disease responded to the biological treatment regimen with complete metabolic remissions.ConclusionDual inhibition of BRAF and downstream MEK may be a safe and effective therapeutic strategy for BRAF-mutant ECD patients for whom BRAF inhibitor therapy proved insufficient and as such appropriate for the long-term management of CNS disease in ECD.

Pharmacological targeting of β2 -adrenoceptors is neuroprotective in the LPS inflammatory rat model of Parkinson's disease.

Chronic inflammation may play a role in the pathogenesis of Parkinson's disease (PD). Noradrenaline is an endogenous neurotransmitter with anti-inflammatory properties. In the present investigation, we assessed the immunomodulatory and neuroprotective efficacy of pharmacologically targeting the CNS noradrenergic system in a rat model of PD. The impact of treatment with the β2 -adrenoceptor agonists clenbuterol and formoterol was assessed in the intranigral LPS rat model of PD. The immunomodulatory potential of formoterol to influence the CNS response to systemic inflammation was also assessed. LPS-induced deficits in motor function (akinesia and forelimb-use asymmetry) and nigrostriatal dopamine loss were rescued by both agents. Treatment with the noradrenaline reuptake inhibitor atomoxetine reduced striatal dopamine loss and motor deficits following intranigral LPS injection. Co-treatment with the β2 -adrenoceptor antagonist ICI 118,551 attenuated the protective effects of atomoxetine. Systemic LPS challenge exacerbated reactive microgliosis, IL-1β production, dopamine cell loss in the substantia nigra, nerve terminal degeneration in the striatum, and associated motor impairments in animals that previously received intranigral LPS. This exacerbation was attenuated by formoterol treatment. The results indicate that pharmacologically targeting β2 -adrenoceptors has the propensity to regulate the neuroinflammatory phenotype in vivo and may be a potential neuroprotective strategy where inflammation contributes to the progression of dopaminergic neurodegeneration. In accordance with this, clinical agents such as β2 -adrenoceptor agonists may prove useful as immunomodulatory agents in the treatment of neurodegenerative conditions associated with brain inflammation.

P2.14-69 Lorlatinib Rescue Therapy for Life Threatening CNS Disease in Crizotinib-Resistant ROS1-Positive Non–Small Cell Lung Cancer (NSCLC)

C-ros proto-oncogene-1 (ROS1) chromosomal translocations result in constitutively activated receptor tyrosine kinase in 1-2% of NSCLC. Although crizotinib, a first-generation Tyrosine Kinase Inhibitor (TKI) of Anaplastic Lymphoma Kinase (ALK) and ROS1 translocations, has demonstrated efficacy in treatment of ROS1 NSCLC, patients invariably acquire resistance mutations, with a high incidence of brain metastasis at relapse owing to poor CNS drug penetration. Lorlatinib is a novel, third-generation TKI with improved CNS penetration and preclinical activity against crizotinib-resistance mutations, which recently demonstrated efficacy in a phase I/II trial. We report a patient who developed secondary crizotinib-resistance and was successfully treated with lorlatinib. A 73-year-old, female, never-smoker with recently diagnosed stage-IV ROS1-rearranged NSCLC presented with refractory seizures and coma. The patient was on first-line treatment with crizotinib for 6-months, with an excellent systemic response at 2 months. Brain MRI after presentation demonstrated multiple intracranial metastasis with vasogenic edema (Fig.1A). Neurologic status was unchanged despite mannitol, steroids and anti-epileptics. As salvage therapy, the patient received bevacizumab for vasogenic edema and lorlatinib (100mg/daily). After 48-hours, substantial clinical improvement in neurologic function and mental status was observed. A repeat MRI (D+4) demonstrated a slight interval decrease in the largest metastasis and associated edema. At 1-month follow-up, the patient continued to improve clinically with no evidence of lorlatinib toxicity. Brain MRI showed a decrease in the sizes and/or resolution of all previously noted lesions and no new metastases or significant peritumoral edema (Fig.1B). Since clinical trials typically exclude patients with symptomatic, untreated CNS disease, efficacy of newer, targeted agents in mutated-NSCLC is unclear. Here we report on a patient with life threatening, acute neurologic deterioration who derived a meaningful clinical reduction in CNS lesions at 1 month, with favorable CNS response at 2 months. In addition, we observed early evidence of tumor regression on MRI after 4 days of lorlatinib therapy. Of note, her rapid clinical response may have in part been attributable to the addition of bevacizumab. Another important consideration for our patient is that she avoided whole-brain radiation in the acute setting, and its potential adverse sequalae. We note a limitation was the absence of available testing for secondary resistance mutations that developed in this patient, which was highly susceptible to lorlatinib. However, current clinical guidelines (NCCN) do not specifically recommend resistance mutation testing upon progression, and outside of a clinical trial, the current algorithm supports lorlatinib as the agent of choice post-crizotinib failure.

Trypanosoma brucei Secreted Aromatic Ketoacids Activate the Nrf2/HO-1 Pathway and Suppress Pro-inflammatory Responses in Primary Murine Glia and Macrophages.

African trypanosomes, such as Trypanosoma brucei (T. brucei), are protozoan parasites of the mammalian vasculature and central nervous system that are best known for causing fatal human sleeping sickness. As exclusively extracellular parasites, trypanosomes are subject to constant challenge from host immune defenses but they have developed very effective strategies to evade and modulate these responses to maintain an infection while simultaneously prolonging host survival. Here we investigate host parasite interactions, especially within the CNS context, which are not well-understood. We demonstrate that T. brucei strongly upregulates the stress response protein, Heme Oxygenase 1 (HO-1), in primary murine glia and macrophages in vitro. Furthermore, using a novel AHADHin T. brucei cell line, we demonstrate that specific aromatic ketoacids secreted by bloodstream forms of T. brucei are potent drivers of HO-1 expression and are capable of inhibiting pro-IL1β induction in both glia and macrophages. Additionally, we found that these ketoacids significantly reduced IL-6 and TNFα production by glia, but not macrophages. Finally, we present data to support Nrf2 activation as the mechanism of action by which these ketoacids upregulate HO-1 expression and mediate their anti-inflammatory activity. This study therefore reports a novel immune evasion mechanism, whereby T. brucei secretes amino-acid derived metabolites for the purpose of suppressing both the host CNS and peripheral immune response, potentially via induction of the Nrf2/HO-1 pathway.

Abstract 4832: Preclinical evaluation of neratinib plus T-DM1 in orthotopic PDX models of HER2-positive breast cancer brain metastases

Abstract Up to half of patients with metastatic HER2-positive breast cancer will develop brain metastases. Breast cancer brain metastases (BCBM) are a major cause of morbidity and mortality, despite multimodal management including surgery, radiotherapy, and systemic therapies. Therefore, there is an urgent need to develop novel, efficacious therapies. Neratinib is an orally bioavailable, irreversible pan-HER tyrosine kinase inhibitor that is FDA-approved in the extended adjuvant treatment setting for HER2-positive, early breast cancer. Neratinib has only modest activity as a single agent in clinical trials of patients with HER2-positive brain metastases. Though the combination of neratinib and capecitabine results in CNS responses in up to half of patients, patients eventually develop drug resistance, and toxicities have been a concern-thus exploration of alternative neratinib combinations is of significant clinical interest. Ado-trastuzumab emtansine (T-DM1) is an antibody-drug conjugate with reported single-agent activity against HER2-positive BCBM. Here, we used HER2-positive orthotopic patient derived xenograft (PDX) models of BCBM to test if combining neratinib with T-DM1 could improve tumor response. PDX cells are labelled with luciferase to allow tumor growth measurement in vivo. We found that neratinib is able to reduce phosphorylated HER2 in an orthotopic PDX tumor derived from HER2-positive BCBM, indicating that neratinib can cross the BBB and inhibit HER2 activation in BCBM PDX tissues. However, in the HER2-positive DF-BM354 PDX model, single agent neratinib did not block orthotopic tumor growth compared to vehicle control as monitored by bioluminescence measurements. In contrast, combined treatment of neratinib with T-DM1 significantly reduced tumor growth compared to single agent treatment of neratinib or T-DM1 alone at earlier time points. At later time points, the combined treatment is comparable to T-DM1 alone. These data warrant further testing of neratinib alone or in combination with T-DM1 in additional BCBM PDX models to better understand drivers of resistance and susceptibility to HER2-inhibitors in HER2-positive BCBMs. Furthermore, they support the launch of a prospective clinical trial (NCT01494662) to test the efficacy and tolerability of T-DM1 in combination with neratinib in patients with progressive HER2-positive BCBM. Citation Format: Jing Ni, Yanzhi Wang, Irmina Diala, Sheheryar Kabraji, Rachel Freedman, Nancy Lin, Jean Zhao. Preclinical evaluation of neratinib plus T-DM1 in orthotopic PDX models of HER2-positive breast cancer brain metastases [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4832.

Phase II study of eribulin mesylate for treatment of CNS metastases (mets) in metastatic breast cancer (mBC).

e12571 Background: There is no approved drug therapy for CNS mets from mBC. Eribulin mesylate (eribulin) is a microtubule inhibitor approved for treatment of mBC patients (pts) who have received at least 2 prior chemotherapy regimens. Previously reported cases have demonstrated significant CNS responses in mBC pts treated with eribulin. This study evaluates the CNS response in pts with mBC treated with eribulin. Methods: CASE7113 was a prospective phase II single-arm study to evaluate the 12-week CNS progression free survival (12-wk CNS-PFS) of pts with mBC and CNS mets treated with eribulin. 20 pts were to be enrolled to demonstrate a 40% 12-wk CNS-PFS (95% CI, 8.5% - 61.5%). All pts had radiologically confirmed mBC CNS lesions with at least one lesion that did not receive prior radiation or surgical resection. Eribulin was administered at standard dose of 1.4mg/m2 IV on days 1 and 8 of a 21 day-cycle. Pts underwent baseline and 12-week brain MRI. The study was closed due to slow accrual; an analysis of enrolled pts was performed. Results: 9 female pts were enrolled; median age was 56 (32-82) years. 55% and 67% had ER+ and/or PR+ and Her2+ mBC respectfully. 1 pt had triple negative breast cancer (TNBC). Median number of prior therapies was 3 (0-12). The 12-wk CNS-PFS (95% CI) was 88.9% (51.8% - 99.7%), the median PFS (95% CI) was 22.6 (4.3 - 31.9) weeks, the median OS (95% CI) was 15.7 (4.0 - 27.3) months. 4 pts achieved stable disease and 1 pt had a partial response. There were no unexpected toxicities. Conclusions: For mBCa pts with CNS mets, this estimate of 12-wk CNS-PFS suggests activity of eribulin and merits further investigation in this population in the context of clinical trials. Clinical trial information: NCT02581839.

Outcomes of melanoma patients with brain metastases receiving immune checkpoint inhibitor (ICI) therapy.

e21028 Background: The effect of ICI therapy on brain metastasis (mets) in melanoma patients has been described, however the impact of genomic alterations and local treatment (trt) including radiation therapy (RT) on CNS outcomes and overall survival (OS) has not yet been explored. Methods: Under institutional IRB approval, we reviewed our electronic medical record to identify patients (pts) with metastatic melanoma and brain mets who received trt with ICI. Trt history, CNS responses as indicated by the treating physician and available genomic data were recorded. OS was estimated using a multivariable Cox regression model adjusting for genomic alteration, age, ICI regimen and brain mets. Results: A total of 49 pts were identified (65% male). Thirty seven pts had testing for tumor genomic alterations (alt, hotspot and comprehensive genomic testing); BRAFV600E( 30%), cKIT(5%), NRAS(16%), no alt (38%). Prior to initiation of ICI, 78% had known CNS mets, of these, 61% received RT. There was no difference in median OS for pts who started RT prior to ICI compared to those without RT (mOS = 75.71 vs 49.4 weeks, p = 0.75). Median OS was improved for those pts who received RT &gt; 90 days prior to initiation of ICI trt however this was not statistically significant (45.7 vs 136 weeks, p = 0.12) and HR = 0.45 (95% CI 0.08, 2.36). OS was not significantly different in pts with genomic alterations compared with those without alterations (p = 0.264). Of the pts with known brain mets at the time of ICI start, 34% had progressive disease at 3 months and 11% were felt to have pseudoprogression. 18% survived to undergo 6-month disease assessment, of these 12% had further progression. All pts with cKIT mutations survived to 6-month disease assessment. 75% of pts with known brain mets developed new lesions, 15% had increased mass size. Pts who developed new brain mets while on trt with ICI had worse survival than those with preexisting brain mets and developed new brain lesions (28 vs 58 weeks, p = 0.05). 6% of all pts developed CNS immune related adverse effects. Conclusions: Most patients with melanoma and known brain metastasis prior to ICI developed new brain lesions as a site of metastatic spread. The development of new brain mets was associated with worse outcomes. Neither genomic alterations nor RT prior to ICI start were associated with improved survival.