Change in non-small-cell lung cancer tumor size in patients treated with nintedanib plus docetaxel: analyses from the Phase III LUME-Lung 1 study

Background

Nintedanib in combination with docetaxel is approved in the European Union and other countries for the treatment of patients with advanced non-small-cell lung cancer (NSCLC) of adenocarcinoma histology after first-line chemotherapy, based on the overall survival findings of Phase III LUME-Lung 1 study. Change in target lesion size over time as a treatment effect was assessed in patients from this study.

Methods

Tumor size was evaluated using predefined tumor measurements. Mixed-effects models were used to quantify individual relationships between time from randomization and tumor burden, measured as the sum of longest diameter (SLD) of target lesions and assessed by an independent review (Response Evaluation Criteria In Solid Tumors [RECIST] v1.0). Exploratory analyses were conducted on the overall adenocarcinoma population, adenocarcinoma patients with time from start of first-line therapy <9 months (TSFLT <9), adenocarcinoma patients who had progressive disease as best response to first-line therapy (PD-FLT), and in squamous cell carcinoma patients.

Results

Estimated mean baseline SLD was 82.5 mm in the adenocarcinoma (n=658), 88.3 mm in the TSFLT <9 (n=405), 98.1 mm in the PD-FLT (n=117), and 94.3 mm in the squamous cell carcinoma (n=555) populations. Treatment with nintedanib/docetaxel showed a significant reduction in tumor size over time (P<0.0001) in patients with adenocarcinoma compared with placebo/docetaxel, and in patients with squamous cell carcinoma (P=0.0049). Treatment difference at 6 months was 9.7 mm in the overall adenocarcinoma population, 16.8 mm in the TSFLT <9 population, 19.7 mm in the PD-FLT population, and 6.8 mm in the squamous cell carcinoma population. SLD at 2 months post-randomization was identified as a surrogate endpoint for overall survival, in addition to progression-free survival, for all except the PD-FLT population.

Conclusion

Treatment with nintedanib/docetaxel significantly decreased tumor burden and decelerated tumor size over time compared with placebo/docetaxel in the overall adenocar-cinoma population, including in patients with the poorest prognosis due to aggressive tumor dynamics.

Embracing model-based designs for dose-finding trials

BACKGROUND

Dose-finding trials are essential to drug development as they establish recommended doses for later-phase testing. We aim to motivate wider use of model-based designs for dose finding, such as the continual reassessment method (CRM).

METHODS

We carried out a literature review of dose-finding designs and conducted a survey to identify perceived barriers to their implementation.

RESULTS

We describe the benefits of model-based designs (flexibility, superior operating characteristics, extended scope), their current uptake, and existing resources. The most prominent barriers to implementation of a model-based design were lack of suitable training, chief investigators' preference for algorithm-based designs (e.g., 3+3), and limited resources for study design before funding. We use a real-world example to illustrate how these barriers can be overcome.

CONCLUSIONS

There is overwhelming evidence for the benefits of CRM. Many leading pharmaceutical companies routinely implement model-based designs. Our analysis identified barriers for academic statisticians and clinical academics in mirroring the progress industry has made in trial design. Unified support from funders, regulators, and journal editors could result in more accurate doses for later-phase testing, and increase the efficiency and success of clinical drug development. We give recommendations for increasing the uptake of model-based designs for dose-finding trials in academia.

Comprehensive Biomarker Analyses in Patients with Advanced or Metastatic Non-Small Cell Lung Cancer Prospectively Treated with the Polo-Like Kinase 1 Inhibitor BI2536

BACKGROUND

Polo like kinase 1 (PLK1) is frequently upregulated in tumors and is thus viewed as a promising therapeutic target in various cancers. Several PLK1 inhibitors have recently been developed and clinically tested in solid cancers, albeit with limited success. So far, no predictive biomarkers for PLK1 inhibitors have been established. To this end, we conducted a post-hoc biomarker analysis of tumor samples from non-small cell lung cancer (NSCLC) patients treated with the PLK1 inhibitor BI2536 in a phase II study.

METHODS

We analyzed formalin-fixed paraffin-embedded surplus tumor tissue from 47 study patients using immunohistochemistry (IHC) and DNA sequencing of KRAS, EGFR, BRAF, and PIK3CA.

RESULTS

KRAS-mutated patients showed numerically prolonged progression-free survival, but statistical significance was not established. Interestingly, when pathways rather than single genes were analyzed, a positive correlation between IHC staining of activated ERK (p-ERK) and mutated KRAS was detected, whereas KRAS mutation status was found to be negatively correlated with activated AKT (p-AKT).

CONCLUSION

With this hypothesis-generating study in BI2531-treated patients, we could not establish a correlation between KRAS mutations and relevant clinical endpoints. Future clinical trials with concomitant systematic biosampling and comprehensive molecular analyses are required to identify biomarkers predictive for response to PLK1 inhibitors.

Time since start of first-line therapy as a predictive clinical marker for nintedanib in patients with previously treated non-small cell lung cancer

Introduction

No predictive clinical or genetic markers have been identified or validated for antiangiogenic agents in lung cancer. We aimed to identify a predictive clinical marker of benefit for nintedanib, an angiokinase inhibitor, using data from two large second-line non-small cell lung cancer Phase III trials (LUME-Lung 1 ([LL1] and LUME-Lung 2).

Methods

Predictive marker identification was conducted in a multi-step process using data from both trials; a hypothesis was generated, confirmed and validated. Statistical analyses included a stepwise selection approach, a recursive partitioning method and the evaluation of HRs, including treatment-by-covariate interactions. The marker was finally validated using a prospectively defined hierarchical testing procedure and treatment-by-covariate interaction for overall survival (OS) based on LL1.

Results

Time since start of first-line therapy (TSFLT) was identified as the only predictive clinical marker. A cut-off of 9 months was chosen for further analysis, based on HRs and recursive partitioning. The prospectively defined final validation using OS data from LL1 established the strong relationship between TSFLT and treatment with nintedanib. Patients with adenocarcinoma with TSFLT <9 months showed a greater survival benefit (median OS 10.9 vs 7.9 months, HR 0.75 [95% CI 0.60–0.92]; p=0.0073) compared with patients in the TSFLT >9 months group (median OS 17.0 vs 15.1 months, HR 0.89 [95% CI 0.66–1.19]).

Conclusions

Patients with shorter TSFLT derive a greater progression-free survival and OS benefit from nintedanib. This clinical marker could be used for patient selection and further investigation is warranted regarding pathways promoting aggressive tumour growth and antiangiogenic tyrosine kinase inhibitor benefit.

Docetaxel plus nintedanib versus docetaxel plus placebo in patients with previously treated non-small-cell lung cancer (LUME-Lung 1): a phase 3, double-blind, randomised controlled trial

BACKGROUND

The phase 3 LUME-Lung 1 study assessed the efficacy and safety of docetaxel plus nintedanib as second-line therapy for non-small-cell lung cancer (NSCLC).

METHODS

Patients from 211 centres in 27 countries with stage IIIB/IV recurrent NSCLC progressing after first-line chemotherapy, stratified by ECOG performance status, previous bevacizumab treatment, histology, and presence of brain metastases, were allocated (by computer-generated sequence through an interactive third-party system, in 1:1 ratio), to receive docetaxel 75 mg/m(2) by intravenous infusion on day 1 plus either nintedanib 200 mg orally twice daily or matching placebo on days 2-21, every 3 weeks until unacceptable adverse events or disease progression. Investigators and patients were masked to assignment. The primary endpoint was progression-free survival (PFS) by independent central review, analysed by intention to treat after 714 events in all patients. The key secondary endpoint was overall survival, analysed by intention to treat after 1121 events had occurred, in a prespecified stepwise order: first in patients with adenocarcinoma who progressed within 9 months after start of first-line therapy, then in all patients with adenocarcinoma, then in all patients. This trial is registered with ClinicalTrials.gov, number NCT00805194.

FINDINGS

Between Dec 23, 2008, and Feb 9, 2011, 655 patients were randomly assigned to receive docetaxel plus nintedanib and 659 to receive docetaxel plus placebo. The primary analysis was done after a median follow-up of 7·1 months (IQR 3·8-11·0). PFS was significantly improved in the docetaxel plus nintedanib group compared with the docetaxel plus placebo group (median 3·4 months [95% CI 2·9-3·9] vs 2·7 months [2·6-2·8]; hazard ratio [HR] 0·79 [95% CI 0·68-0·92], p=0·0019). After a median follow-up of 31·7 months (IQR 27·8-36·1), overall survival was significantly improved for patients with adenocarcinoma histology who progressed within 9 months after start of first-line treatment in the docetaxel plus nintedanib group (206 patients) compared with those in the docetaxel plus placebo group (199 patients; median 10·9 months [95% CI 8·5-12·6] vs 7·9 months [6·7-9·1]; HR 0·75 [95% CI 0·60-0·92], p=0·0073). Similar results were noted for all patients with adenocarcinoma histology (322 patients in the docetaxel plus nintedanib group and 336 in the docetaxel plus placebo group; median overall survival 12·6 months [95% CI 10·6-15·1] vs 10·3 months [95% CI 8·6-12·2]; HR 0·83 [95% CI 0·70-0·99], p=0·0359), but not in the total study population (median 10·1 months [95% CI 8·8-11·2] vs 9·1 months [8·4-10·4]; HR 0·94, 95% CI 0·83-1·05, p=0·2720). Grade 3 or worse adverse events that were more common in the docetaxel plus nintedanib group than in the docetaxel plus placebo group were diarrhoea (43 [6·6%] of 652 vs 17 [2·6%] of 655), reversible increases in alanine aminotransferase (51 [7·8%] vs six [0·9%]), and reversible increases in aspartate aminotransferase (22 [3·4%] vs three [0·5%]). 35 patients in the docetaxel plus nintedanib group and 25 in the docetaxel plus placebo group died of adverse events possibly unrelated to disease progression; the most common of these events were sepsis (five with docetaxel plus nintedanib vs one with docetaxel plus placebo), pneumonia (two vs seven), respiratory failure (four vs none), and pulmonary embolism (none vs three).

INTERPRETATION

Nintedanib in combination with docetaxel is an effective second-line option for patients with advanced NSCLC previously treated with one line of platinum-based therapy, especially for patients with adenocarcinoma.

FUNDING

Boehringer Ingelheim.

Nintedanib (BIBF 1120) plus docetaxel in NSCLC patients progressing after first-line chemotherapy: LUME Lung 1, a randomized, double-blind phase III trial

LBA8011

Background: Nintedanib (N) inhibits VEGFRs, PDGFRs, and FGFRs. LUME Lung 1 is a placebo (P) controlled phase III trial of N + docetaxel (D) in patients (pts) with locally advanced/metastatic NSCLC progressing after first-line therapy. Methods: Stage IIIB/IV or recurrent NSCLC pts (stratified by histology, ECOG PS, prior bevacizumab, and brain metastases) were randomized to N 200 mg bid + D 75 mg/m2 q21d (n=655) or P + D (n=659). 1° endpoint was centrally reviewed PFS after 713 events (2 sided stratified log-rank, α=5%, β=10%). Key 2° endpoint of OS was analyzed hierarchically after 1,121 events (2 sided, adjusted α=4.98%, β=20%), first in adenocarcinoma (adeno) pts <9 mo since start of first-line therapy (T<9mo; identified as a prognostic/predictive biomarker [ASCO ‘13]), followed by all adeno pts and then all pts. Predefined sensitivity analyses added sum of longest diameters of target lesions (SLD) to stratification factors in the Cox model. Results: Pt characteristics were balanced between the arms. N + D significantly prolonged PFS vs P + D (HR 0.79; CI: 0.68, 0.92; p=0.0019; median 3.4 vs 2.7 mo) regardless of histology (squamous HR 0.77, p=0.02; adeno HR 0.77, p=0.02). OS was significantly prolonged in all adeno pts (HR 0.83; p=0.0359; median 12.6 vs 10.3 mo) with the greatest improvement seen in T<9mo adeno pts (HR 0.75; p=0.0073; median 10.9 vs 7.9 mo). A trend for improved OS was seen in all pts (HR 0.94; p=0.272; median 10.1 vs 9.1). When adjusted for SLD, a significant OS benefit was seen in all pts (HR 0.88; CI: 0.78, 0.99; p=0.0365). Disease control rates were significantly improved with N + D in all adeno pts (odds ratio [OR] 1.93; p<0.0001), T<9mo adeno pts (OR 2.90; p<0.0001) and all pts (OR 1.68; p<0.0001). The most common AEs were diarrhea (any: 42.3 vs 21.8%; Gr ≥3: 6.6 vs 2.6%) and ALT elevations (any: 28.5 vs 8.4%; Gr ≥3: 7.8 vs 0.9%). Incidence of CTCAE Gr ≥3 AEs was 71.3 vs 64.3%. Withdrawals due to AEs (22.7 vs 21.7%) were similar in both arms, as were Gr ≥3 hypertension, bleeding or thrombosis. Conclusions: N + D significantly improved PFS independent of histology, and prolonged OS for adeno pts. AEs were generally manageable with dose reductions and symptomatic treatment. Clinical trial information: NCT00805194.

Lume-lung 2: A multicenter, randomized, double-blind, phase III study of nintedanib plus pemetrexed versus placebo plus pemetrexed in patients with advanced nonsquamous non-small cell lung cancer (NSCLC) after failure of first-line chemotherapy

8034

Background: Nintedanib (N) is an oral inhibitor of VEGFR, FGFR, and PDGFR. This global phase 3 study investigated the safety and efficacy of N + pemetrexed (PEM) vs placebo (P) + PEM in patients (pts) with advanced, non-squamous NSCLC previously treated with chemotherapy. Methods: Pts were randomized 1:1 to N 200 mg po bid + PEM 500 mg/m2 iv q21d (n=353, Arm A) or P + PEM (n=360, Arm B). Continuation until PD or unacceptable toxicity with N, P, PEM, or a combination was permitted. 1° endpoint was centrally reviewed PFS. The null hypothesis was tested on the ITT population after 394 events had occurred (two sided α=5%). 2° endpoints included OS, investigator-assessed PFS, response rate (RR), safety, and QoL. Results: Baseline pt characteristics were balanced between Arm A vs B (median age 59 y, female 45–42%, ECOG PS 1 62-61%, adenocarcinoma 95–93%, prior bevacizumab 8%). Based on a planned DMC futility analysis of investigator-assessed PFS, enrolment was halted after randomizing 713/1300 planned pts (no safety issues identified). Ongoing pts were unblinded and follow-up continued per protocol. Subsequent ITT analysis of the 1° endpoint (centrally reviewed PFS) favored Arm A vs B (median 4.4 vs 3.6 mo, HR 0.83 [95% CI: 0.7–0.99], p=0.04). Disease control was also significantly improved in N-treated pts (61 vs 53%, odds ratio 1.37, p=0.039). No difference in OS (HR 1.03) or RR (9%) was found. Exploratory analyses identified time since start of 1st-line therapy as a predictive marker of improved outcome with N + PEM (ASCO 2013). There was no increase in SAEs or G5 AEs with N + PEM. Addition of N to PEM resulted in a higher incidence of ≥G3 elevated ALT (23 vs 7%), elevated AST (12 vs 2%), and diarrhea (3 vs 1%), but no difference in ≥G3 hypertension, bleeding, thrombosis, mucositis, or neuropathy. Conclusions: The 1° endpoint was met even though the study was stopped prematurely. Treatment with N + PEM significantly improved centrally reviewed PFS vs P + PEM in pts with advanced non-squamous NSCLC previously treated with chemotherapy, and had a manageable safety profile. Clinical trial information: NCT00806819.

Nintedanib (BIBF 1120) plus docetaxel in NSCLC patients progressing after one prior chemotherapy regimen: Results of Lume-Lung 1, a randomized, double-blind, phase III trial

LBA8011

The full, final text of this abstract will be available at abstract.asco.org at 7:30 AM (EDT) on Monday, June 3, 2013, and in the Annual Meeting Proceedings online supplement to the June 20, 2013, issue of Journal of Clinical Oncology. Onsite at the Meeting, this abstract will be printed in the Monday edition of ASCO Daily News.

A phase I open-label dose-escalation study of intravenous BI 2536 together with pemetrexed in previously treated patients with non-small-cell lung cancer

INTRODUCTION

BI 2536 is a potent, highly selective inhibitor of polo-like kinase (Plk) 1. This open-label, phase I study investigated the maximum tolerated dose (MTD), safety, efficacy, and pharmacokinetics (PK) of BI 2536 IV in combination with standard-dose pemetrexed in previously treated advanced or metastatic non-small-cell lung cancer.

PATIENTS AND METHODS

A standard 3 + 3 design was used. The patients received 500 mg/m(2) pemetrexed and escalating doses of BI 2536 on day 1 every 3 weeks. The primary objective was the MTD of BI 2536 combined with pemetrexed. Secondary endpoints were response rate (Response Evaluation Criteria in Solid Tumors), overall safety, and PK.

RESULTS

Forty-one patients received BI 2536 (100-325 mg). Two dose-limiting toxicities (DLT) occurred at BI 2536 325 mg (grade 3 pruritus and rash; grade 4 neutropenia). Therefore, the MTD for BI 2536 in combination with pemetrexed was 300 mg. After expanding the MTD dose level, 3 additional patients experienced DLTs, which resulted in expansion of the 250 mg cohort, in which 4 of the 13 additional patients experienced DLTs. Therefore, the recommended dose of BI 2536 was 200 mg. Most frequently reported drug-related adverse events were fatigue (71%), nausea (37%), and rash (34%). Two patients had durable confirmed partial responses; 21 (54%) patients had stable disease after the treatment cycle 2. PK analysis showed that BI 2536 and pemetrexed exposure were not altered when coadministered.

CONCLUSION

BI 2536 200 mg combined with standard-dose pemetrexed has an acceptable safety profile in relapsed non-small-cell lung cancer. The antitumor activity observed is encouraging and supports further investigation of Plk inhibitors.

Anomalous Auditory Cortex Activations in Colored Hearing Synaesthetes: An fMRI-Study

Color percept induction in synaesthetes by hearing words was previously shown to involve activation of visual and specifically color processing cortex areas. While this provides a rationale for the origin of the anomalous color percept the question of mechanism of this crossmodal activation remains unclear. We pursued this question with fMRI in color hearing synaesthetes by exposing subjects to words and tones. Brain activations in word condition accompanied by highly reliable color percepts were compared with activations in tone condition with only occasional color percepts and both contrasted to activations in normal subjects under the same stimulus conditions. This revealed that already the tone condition similar to the word condition caused abnormally high activations in various cortical areas even though synaesthetic percepts were more rare. Such tone activations were significantly larger than in normal subjects in visual areas of the right occipital lobe, the fusiform gyrus, and the left middle temporal gyrus and in auditory areas of the left superior temporal gyrus. These auditory areas showed strong word and tone activation alike and not the typically lower tone than word activation in normal subjects. Taken together these results are interpreted in favour of the disinhibited feedback hypothesis as the neurophysiological basis of genuine synaesthesia.

The efficacy and safety of BI 2536, a novel Plk-1 inhibitor, in patients with stage IIIB/IV non-small cell lung cancer who had relapsed after, or failed, chemotherapy: results from an open-label, randomized phase II clinical trial

OBJECTIVE

To investigate the efficacy, safety, and pharmacokinetics of two dosing schedules of BI 2536, a novel polo-like kinase-1 inhibitor, in patients with relapsed stage IIIB/IV non-small cell lung cancer.

METHODS

Ninety-five patients were randomized to intravenous BI 2536 on day 1 (200 mg) or days 1 to 3 (50 or 60 mg) of a 21-day treatment course. BI 2536 doses were escalated beyond course 2 if well tolerated. The primary objective was response, and the secondary objectives were progression-free survival (PFS) and overall survival (OS), quality of life, safety, and pharmacokinetics. Primary statistical aim was to demonstrate the difference in objective response rate to historical placebo for both treatment groups.

RESULTS

Four patients (4.2%) had a partial response; two were confirmed by independent review. Median PFS was 8.3 weeks (58 days 95% confidence interval [CI]: 48-85) and 7 weeks (49 days 95% CI: 46-70) assessed by investigator and independent review, respectively. Median OS was 28.7 weeks (201 days 95% CI: 180-305). No statistically significant difference was observed between the two treatment schedules regarding clinical benefit, PFS, or OS. Grade 4 neutropenia occurred in 37% of patients; common nonhematologic adverse events were fatigue (31%) and nausea (27%). Two deaths (pulmonary hemorrhage and sepsis) were considered drug related. There was a trend in favor of the days 1 to 3 dosing schedule in quality of life. BI 2536 displayed moderate interpatient variability.

CONCLUSIONS

BI 2536 monotherapy has modest efficacy and favorable safety in relapsed non-small cell lung cancer. The findings support the further development of polo-like kinase-1 inhibitors within this indication.

Phase I study of the angiogenesis inhibitor BIBF 1120 in patients with advanced solid tumors

PURPOSE

BIBF 1120 is an oral, potent angiokinase inhibitor targeting receptors of the vascular endothelial growth factors, platelet-derived growth factors, and fibroblast growth factors. This phase I, accelerated titration study assessed the maximum tolerated dose, safety, pharmacokinetics, and pharmacodynamic effects of BIBF 1120.

PATIENTS AND METHODS

Sixty-one patients with advanced cancers received BIBF 1120 in successive cohorts. Twenty-five received 50 to 450 mg once daily and 36 received 150 to 300 mg twice daily in 4-week treatment courses interspersed by 1 week of washout. Dynamic contrast-enhanced magnetic resonance imaging assessed antiangiogenic effect in 42 patients.

RESULTS

Most frequent BIBF 1120-related adverse events were mostly mild to moderate (Common Toxicity Criteria grade 1-2) nausea (68.9%), vomiting (45.9%), and diarrhea (44.3%). The majority of dose-limiting adverse events of Common Toxicity Criteria grade 3 or 4 were reversible liver enzyme elevations. The maximum tolerated dose was 250 mg of BIBF 1120 for once and twice daily dosing. BIBF 1120 was absorbed moderately fast (t(max) = 1-3 hours at steady state), with no deviation from dose linearity and no decrease of exposure over time. The gMean terminal half-life was from 13 to 19 hours. One complete and two partial responses occurred in patients with renal cell cancer (n = 2) and colorectal cancer (n = 1). Dynamic contrast-enhanced magnetic resonance imaging showed a significant reduction in tumor blood flow in 55% of evaluable patients.

CONCLUSIONS

BIBF 1120 dosed continuously displayed a favorable safety and pharmacokinetics profile, and first efficacy signals were observed. Twice daily dosing permitted increased drug exposure without additional toxicity. Two hundred milligrams BIBF 1120 twice daily is the recommended dose for phase II monotherapy studies.

An open-label dose-escalation study of BIBF 1120 in patients with relapsed or refractory multiple myeloma

BACKGROUND

To determine the maximum tolerated dose (MTD) and dose-limiting toxicities (DLTs) of BIBF 1120, a triple angiokinase inhibitor administered once-daily in patients with advanced multiple myeloma.

PATIENTS AND METHODS

This Phase I study included 17 patients. Planned dose escalations of BIBF 1120 were 100, 200, 250 and 300 mg. Safety and pharmacokinetic (PK) assessments were performed.

RESULTS

Two DLTs (200 and 250 mg) occurred due to increased gamma-glutamyltransferase levels (CTC grade 3). The 250 mg dose was well tolerated; no dose escalation beyond 250 mg was made. The most common adverse events included diarrhoea, nausea and vomiting. No detectable deviation from dose linear PKs was observed. Regarding tumour control, two patients had stable disease for > or = 4 months.

CONCLUSION

BIBF 1120 was safe and well tolerated up to 250 mg/day. The MTD was not reached.

Working memory specific activity in auditory cortex: potential correlates of sequential processing and maintenance

Working memory (WM) tasks involve several interrelated processes during which past information must be transiently maintained, recalled, and compared with test items according to previously instructed rules. It is not clear whether the rule-specific comparisons of perceptual with memorized items are only performed in previously identified frontal and parietal WM areas or whether these areas orchestrate such comparisons by feedback to sensory cortex. We tested the latter hypothesis by focusing on auditory cortex (AC) areas with low-noise functional magnetic resonance imaging in a 2-back WM task involving frequency-modulated (FM) tones. The control condition was a 0-back task on the same stimuli. Analysis of the group data identified an area on right planum temporale equally activated by both tasks and an area on the left planum temporale specifically involved in the 2-back task. A region of interest analysis in each individual revealed that activation on the left planum temporale in the 2-back task positively correlated with the task performance of the subjects. This strongly suggests a prominent role of the AC in 2-back WM tasks. In conjunction with previous findings on FM processing, the left lateralized effect presumably reflects the complex sequential processing demand of the 2-back matching to sample task.

Auditory stream segregation relying on timbre involves left auditory cortex

An important aspect of auditory scene analysis is sequential grouping of sounds that are similar to one another in preference to sounds that follow one another. This grouping problem is captured by stream segregation tasks with alternating distinct sounds. We examined human auditory cortex activity with low noise fMRI in a stream segregation experiment relying on timbre differences of alternating harmonic tones (organ-like and trumpet-like). We found that stream segregation performance in comparison to monitoring a non-separable control stream increased activation exclusively in left auditory cortex and particularly in posterior areas. Our results suggest that left auditory cortex is selectively involved in this complex sequential task although the available cue for sequential grouping was timbre, usually attributed to right hemisphere analysis.

Lateralized auditory spatial perception and the contralaterality of cortical processing as studied with functional magnetic resonance imaging and magnetoencephalography

Functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG) were used to study the relationships between lateralized auditory perception in humans and the contralaterality of processing in auditory cortex. Subjects listened to rapidly presented streams of short FM-sweep tone bursts to detect infrequent, slightly deviant tone bursts. The stimulus streams consisted of either monaural stimuli to one ear or the other or binaural stimuli with brief interaural onset delays. The onset delay gives the binaural sounds a lateralized auditory perception and is thought to be a key component of how our brains localize sounds in space. For the monaural stimuli, fMRI revealed a clear contralaterality in auditory cortex, with a contralaterality index (contralateral activity divided by the sum of contralateral and ipsilateral activity) of 67%. In contrast, the fMRI activations from the laterally perceived binaural stimuli indicated little or no contralaterality (index of 51%). The MEG recordings from the same subjects performing the same task converged qualitatively with the fMRI data, confirming a clear monaural contralaterality, with no contralaterality for the laterally perceived binaurals. However, the MEG monaural contralaterality (55%) was less than the fMRI and decreased across the several hundred millisecond poststimulus time period, going from 57% in the M50 latency range (20-70 ms) to 53% in the M200 range (170-250 ms). These data sets provide both quantification of the degree of contralaterality in the auditory pathways and insight into the locus and mechanism of the lateralized perception of spatially lateralized sounds.

Electrodynamic headphones and woofers for application in magnetic resonance imaging scanners

Electrodynamic speakers compatible with (functional) magnetic resonance imaging (MRI) are described. The speakers magnets are removed, their function is replaced by the scanner's magnetic field, resulting in an uncommon but efficient operation. The method can be used with headphones as well as woofers. Functional MRI is not associated with any known biological risks, but as a method for visualization of task-specific activation of brain regions it is undesirably noisy. Thus, it requires both noise protection and efficient sound transmission systems for delivering acoustic stimuli to subjects. Woofers could possibly be used in active noise-control systems. The speakers described in this paper can be used for either task.

Functional magnetic resonance imaging of a human auditory cortex area involved in foreground-background decomposition

Auditory foreground-background decomposition is a pattern recognition process which combines simultaneous and sequential grouping in complex sound sequences. Using functional magnetic resonance imaging with reduced scanner noise and stimulation through a new type of earphones, we investigated the possibility that this process activates topographically distinct areas of human auditory cortex. A basic matching-to-sample task with variable tones (sequential grouping) caused significant activity in three separate landmark-related territories on the supratemporal plane. A similar task in the presence of a strongly masking acoustic background pattern to challenge simultaneous grouping led to the distinction of the subterritory in which foreground signal-related or task-related signal properties were exclusively seen. In contrast to the remainder of territories the level of activity and the periodicity of the signal time-course was resistant to the masking influence of the background. This suggests that auditory foreground-background decomposition involves a specialized non-primary auditory cortex field. Generally, the findings demonstrate functional parcellation of auditory cortex for which the evidence in humans, in contrast to other primates, is only indirect to date.

Activation of human auditory cortex in retrieval experiments: an fMRI study

In a previous functional magnetic resonance (fMRI) study, a subdivision of the human auditory cortex into four distinct territories was achieved. One territory (T1a) exhibited functional specialization in terms of a foreground-background decomposition task involving matching-to-sample monitoring on tone sequences. The present study more specifically determined whether memory-guided analysis of tone sequences is part of the T1a specialization. During the encoding periods, an arbitrary and unfamiliar four-tone-sequence (melody) played by one instrument was presented. The melody-instrument-combination was different in each period. During subsequent retrieval periods, learned and additional combinations were presented, and the tasks were either to detect the target melodies (experiment I) or the target instruments (experiment II). T1a showed larger activation during the melody retrieval. The results generally suggest that (1) activation of T1a during retrieval is determined less by the sound material than by the executed task, and (2) more specifically, that memory-guided sequential analysis in T1a is dominant over recognition of characteristic complex sounds.

Lateralized processing of speech prosodies in the temporal cortex: a 3-T functional magnetic resonance imaging study

Prosodic modulation of speech provides information about emotional states of speakers (affective prosodies) or serves as syntactic markers to change linguistic aspects of speech (linguistic prosodies). Previous electrophysiological investigations and studies on patients with right or left hemisphere damage showed nonuniform results with respect to lateralization of prosodic processing. In this study 20 healthy right-handed volunteers were investigated with functional magnetic resonance imaging of the acoustically responsive areas on the supratemporal plane while detecting phonemes as control targets or prosodies in strings of nonsense syllables and adjectives, the latter randomly intonated in a declarative, interrogative, commanding, happy, or sad fashion. In control task A the phoneme /a/ was detected in the syllables. In control task B the phoneme /a/ was detected in the adjectives, and in the experimental task C the sad intonations (affective) and in the experimental task D the interrogative intonations (linguistic) had to be detected in the same material. In task A intensity-weighted volumes of activated voxels were not different in the two hemispheres (laterality index 0). In task B with an irrelevant phoneme detection with respect to prosodic material, the population split into two subgroups with similar right or left hemispheric lateralization of activity leading to an absolute laterality index of 26.8 across all subjects. During detection of affective prosodies (task C), lateralization was maintained yet the absolute laterality index reduced to 14.5, while there was no lateralization during detection of linguistic prosodies. The sum of activations in the two hemispheres was the same across all tasks and subgroups, which suggests that the lateralizations occurring with presentation and detection of prosodic material depend on a redistribution of activity between hemispheres.

Statistical methods in functional magnetic resonance imaging with respect to nonstationary time-series: auditory cortex activity

In awake animal and human auditory cortices, it is a common experience with electrophysiological and suitable imaging methods for responses to steady stimulation to be strongly state-dependent and to exhibit nonstationarities, even over short periods of observation. If such nonstationary behavior is also reflected by hemodynamic responses in the human auditory cortex, conventional methods of analysis of fMRI data, although applicable for instance to largely stationary responses in visual and other cortices, may be misleading in attempts to parcellate auditory cortex into fields and to demonstrate functional maps. Time-Windows, described in this article as a convenient tool for the detection and analysis of time-variant brain activities, solves some of these problems. Time-Windows demonstrates that activity is evoked reliably in three separate territories of human auditory cortex, parts of which may show nonstationary behavior, depending on the auditory stimuli and tasks.