Detection of Volume-Changing Metastatic Brain Tumors on Longitudinal MRI Using a Semiautomated Algorithm Based on the Jacobian Operator Field

BACKGROUND AND PURPOSE

Accurate follow-up of metastatic brain tumors has important implications for patient prognosis and management. The aim of this study was to develop and evaluate the accuracy of a semiautomated algorithm in detecting growing or shrinking metastatic brain tumors on longitudinal brain MRIs.

MATERIALS AND METHODS

We used 50 pairs of successive MR imaging datasets, 30 on 1.5T and 20 on 3T, containing contrast-enhanced 3D T1-weighted sequences. These yielded 150 growing or shrinking metastatic brain tumors. To detect them, we completed 2 major steps: 1) spatial normalization and calculation of the Jacobian operator field to quantify changes between scans, and 2) metastatic brain tumor candidate segmentation and detection of volume-changing metastatic brain tumors with the Jacobian operator field. Receiver operating characteristic analysis was used to assess the detection accuracy of the algorithm, and it was verified with jackknife resampling. The reference standard was based on detections by a neuroradiologist.

RESULTS

The areas under the receiver operating characteristic curves were 0.925 for 1.5T and 0.965 for 3T. Furthermore, at its optimal performance, the algorithm achieved a sensitivity of 85.1% and 92.1% and specificity of 86.7% and 91.3% for 1.5T and 3T, respectively. Vessels were responsible for most false-positives. Newly developed or resolved metastatic brain tumors were a major source of false-negatives.

CONCLUSIONS

The proposed algorithm could detect volume-changing metastatic brain tumors on longitudinal brain MRIs with statistically high accuracy, demonstrating its potential as a computer-aided change-detection tool for complementing the performance of radiologists, decreasing inter- and intraobserver variability, and improving efficacy.

Implementing Clinical Prediction Models: Pushing the Needle Towards Precision Pharmacotherapy

Clinical prediction models promise a future of precision drug therapy. However, very few models are used in practice. Although models can eliminate unwanted clinical guesswork, several barriers hinder model implementation in practice. Here we discuss the less well-recognized barriers hindering model implementation for precision prescribing, highlighting areas that warrant attention, primarily relating to ethical and regulatory considerations that are requisite in paving the way towards a future of precision pharmacotherapy.

Abstract B29: Innate immune modulation: The novel immunotherapeutic Imprime PGG triggers the anti-cancer immunity cycle in concert with tumor-targeting, anti-angiogenic and checkpoint inhibitor antibodies

Cancer immunotherapeutics largely focus on awakening T cell mediated recognition and eradication of tumor cells. Indeed, checkpoint inhibitor antibodies (e.g. pembrolizumab) unleash T cells already involved in anti-cancer responses and have shown remarkable clinical activity, though only in ~20-30% of solid tumor patients. Numerous approaches are being explored to enhance the percent of patients who benefit from checkpoint inhibitor therapies. Chief amongst these are the innate immune modulating therapies collectively designated as PAMPs- pathogen- associated molecular patterns. PAMPs operate as the critical non-self signals that, in response to pathogen infection, ignite the function of the innate immune system to trigger the immunity cycle. TLR and STING agonists acts as PAMPs and reflect bacterial and viral danger signals that can drive dendritic cell maturation, enhancing T cell function. These agents are in development in combination with other immunotherapies, including checkpoint inhibitors, but inspire intolerable cytokine storms and are thereby limited to direct intra-tumoral delivery approaches. We therefore sought to discover and develop a novel, systemically administered PAMP- Imprime PGG (Imprime). Ex vivo studies with whole blood from healthy human donors show that Imprime consistently elicits the activation of innate immune cells. M2 state macrophages repolarize, showing increased expression of M1 markers (CD86, PD-L1) with coincident reduction in M2 markers (CD163, CD206). Dendritic cells (DCs) mature, showing enhanced surface expression of CD80, CD86 and MHC class II. Functionally, the antigen presentation capability of these re-polarized macrophages and activated DCs is substantially enhanced and drives the robust expansion of co-cultured CD8 T cells as well as the marked upregulation of the potent anti-tumor cytokine interferon gamma. In preclinical tumor studies, Imprime is administered IV and profoundly enhances the efficacy of numerous antibody therapies. Using the B16 experimental metastasis model, we show that Imprime (administered IV) synergizes with the anti-TRP1 tumor-targeting antibody TA-99, nearly eradicating B16 metastases as measured by visual counts, TRP-1 RT-PCR and in situ immunofluorescence for TRP1. In the H441 and H1299 non-small cell lung cancer xenografts, Imprime synergizes with the anti-VEGFR2 antibody DC101 to flat-line tumor growth. In the MC-38, CT-26 and 4T-1 syngeneic tumor models, Imprime synergizes with both anti-PD-1 and PD-L1 checkpoint inhibitor antibodies to repress tumor growth and/or to eradicate cancer lesions. In situ imaging of these preclinical tumor tissues repeatedly shows that Imprime instigates a re-orientation of the immune microenvironment, promoting an M1 state (e.g. increased iNOS2, decreased Arginase 1), as well as the influx of myeloid cells and, in the syngenic models, CD8 T cells. In clinical trials in > 400 total patients to date, Imprime has been safely administered by IV infusion (4mg/kg over 2 hours) and has repeatedly shown evidence for efficacy in combination with tumor targeting or anti-angiogenic antibodies. Studies with checkpoint inhibitor antibodies are slated to begin summer of 2016. We now provide the first evidence in healthy human volunteers that Imprime (IV- 4mg/kg, 2 hours) drives the same innate immune activation events evident in the preclinical studies (e.g. chemokine and cytokine release, PD-L1 and CD86 upregulation) verifying that the clinical dose activates the innate immune system. Together, these preclinical and clinical studies provide evidence that the novel PAMP, Imprime PGG, can be safely administered systemically and can drive the critical innate immune activation necessary to spark the anti-cancer immunity cycle.

Citation Format: N Bose, K Gorden, A Chan, A Jonas Bykowski, N Ottoson, D Walsh, X Qiu, B Harrison, T Kangas, K Fraser, R Fulton, S Leonardo, M Uhlik, J Graff. Innate immune modulation: The novel immunotherapeutic Imprime PGG triggers the anti-cancer immunity cycle in concert with tumor-targeting, anti-angiogenic and checkpoint inhibitor antibodies. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2016 Oct 20-23; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2017;5(3 Suppl):Abstract nr B29.

[Monitoring of blood parameters under course-modified MS therapy : Substance-specific relevance and current recommendations for action]

With the approval of various substances for the immunotherapy of multiple sclerosis (MS), treatment possibilities have improved significantly over the last few years. Indeed, the choice of individually tailored preparations and treatment monitoring for the treating doctor is becoming increasingly more complex. This is particularly applicable for monitoring for a treatment-induced compromise of the immune system. The following article by members of the German Multiple Sclerosis Skills Network (KKNMS) and the task force "Provision Structures and Therapeutics" summarizes the practical recommendations for approved immunotherapy for mild to moderate and for (highly) active courses of MS. The focus is on elucidating the substance-specific relevance of particular laboratory parameters with regard to the mechanism of action and the side effects profile. To enable appropriate action to be taken in clinical practice, any blood work changes that can be expected, in addition to any undesirable laboratory findings and their causes and relevance, should be elucidated.

Rate of EGFR mutation testing for patients with nonsquamous non-small-cell lung cancer with implementation of reflex testing by pathologists

BACKGROUND

Testing for mutation of the EGFR (epidermal growth factor receptor) gene is a standard of care for patients with advanced nonsquamous non-small-cell lung cancer (nsclc). To improve timely access to EGFR results, a few centres implemented reflex testing, defined as a request for EGFR testing by the pathologist at the time of a nonsquamous nsclc diagnosis. We evaluated the impact of reflex testing on EGFR testing rates.

METHODS

A retrospective observational review of the Web-based AstraZeneca Canada EGFR Database from 1 April 2010 to 31 March 2014 found centres within Ontario that had requested EGFR testing through the database and that had implemented reflex testing (with at least 2 years' worth of data, including the pre- and post-implementation period).

RESULTS

The 7 included centres had requested EGFR tests for 2214 patients. The proportion of pathologists requesting EGFR tests increased after implementation of reflex testing (53% vs. 4%); conversely, the proportion of medical oncologists requesting tests decreased (46% vs. 95%, p < 0.001). After implementation of reflex testing, the mean number of patients having EGFR testing per centre per month increased significantly [12.6 vs. 4.9 (range: 4.5-14.9), p < 0.001]. Before reflex testing, EGFR testing rates showed a significant monthly increase over time (1.37 more tests per month; 95% confidence interval: 1.19 to 1.55 tests; p < 0.001). That trend could not account for the observed increase with reflex testing, because an immediate increase in EGFR test requests was observed with the introduction of reflex testing (p = 0.003), and the overall trend was sustained throughout the post-reflex testing period (p < 0.001).

CONCLUSIONS

Reflex EGFR testing for patients with nonsquamous nsclc was successfully implemented at multiple centres and was associated with an increase in EGFR testing.

Abstract P4-22-16: First-line ribociclib + letrozole in patients with HR+, HER2– advanced breast cancer (ABC) presenting with visceral metastases or bone-only disease: A subgroup analysis of the MONALEESA-2 trial

Background: Patients with ABC who present with visceral metastases have a worse outcome than patients with non-visceral disease, while patients with bone-only disease tend to have a better prognosis. Ribociclib (LEE011) is an oral, selective inhibitor of cyclin-dependent kinase (CDK) 4/6. In a Phase 3, placebo-controlled, randomized trial (MONALEESA-2; NCT01958021), first-line ribociclib (R) + letrozole (L) significantly prolonged progression-free survival (PFS) vs placebo (P) + L in patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2–) ABC, with a hazard ratio of 0.556 (95% confidence interval [CI]: 0.429–0.720; p=0.00000329) at the interim analysis cut-off date (Jan 29, 2016). Here, we present subgroup analyses in patients with visceral metastases, and those with bone-only disease.

Methods: Postmenopausal women with HR+, HER2– ABC were randomized 1:1 to receive R (600 mg/day; 3-weeks-on/1-week-off) + L (2.5 mg/day; continuous) or P+L, stratified by the presence of liver and/or lung metastases. No prior CDK4/6 inhibitors or systemic therapy for ABC were allowed. Eligible patients had Eastern Cooperative Oncology Group performance status ≤1, baseline alanine/aspartate aminotransferase levels &lt;5× upper limit of normal (ULN) or &lt;2.5× ULN for patients with or without liver metastases, respectively, and ≥1 predominantly lytic bone lesion at baseline for patients with bone-only disease. Locally assessed PFS was analyzed for all patients (primary endpoint), and for predefined patient subgroups.

Results: Overall, 668 patients were randomized; 393 had visceral metastases and 147 had bone-only disease.

 Visceral metastasesBone-only disease n=393n=147 R+LP+LR+LP+L n=197n=196n=69n=78Median age, years (range)63 (23–91)63 (29–88)65 (37–85)63 (37–84)De novo metastatic disease, n (%)53 (27)55 (28)28 (41)24 (31)Non-de novo disease-free interval, n (%)≤24 months12 (6)15 (8)5 (7)6 (8)&gt;24 months132 (67)126 (64)36 (52)48 (62)Discontinued treatment, n (%)83 (42)111 (57)29 (42)40 (51)Reason for discontinuation, n (%)Disease progression56 (28)93 (47)17 (25)31 (40)Patient/physician decision10 (5)15 (8)7 (10)6 (8)Adverse events16 (8)3 (2)4 (6)2 (3)Protocol deviation001 (1)1 (1)Death1 (&lt;1)000

In patients with visceral metastases: Median PFS was not reached in the R+L arm (95% CI: 19.3–not estimable [NE]) vs 13.0 months (95% CI: 12.6 –16.5) in the P+L arm, with hazard ratio 0.535 (95% CI: 0.385–0.742). Median duration of exposure was 12.0 and 13.0 months (R and L, respectively) in the R+L arm, and 12.1 and 12.2 months (P and L, respectively) in the P+L arm.

In patients with bone-only disease: Median PFS was not reached in the R+L arm (95% CI: NE–NE) vs 15.3 months (95% CI: 13.8–NE) in the P+L arm, with hazard ratio 0.690 (95% CI: 0.381–1.249). Median duration of exposure was 12.1 and 12.6 months (R and L, respectively) in the R+L arm, and 12.7 and 12.9 months (P and L, respectively) in the P+L arm.

Conclusions: First-line R+L was well tolerated and significantly prolonged PFS vs P+L in postmenopausal women with HR+, HER2– ABC, both in patients with visceral metastases and those with bone-only disease.

Keywords: Advanced breast cancer; CDK4/6 inhibitor; Letrozole; Ribociclib

Citation Format: Burris HA, Chan A, Campone M, Blackwell KL, Winer EP, Janni W, Verma S, Burdaeva O, Alba E, Favret AM, Mondal S, Miller M, Germa C, Hirawat S, Yap YS. First-line ribociclib + letrozole in patients with HR+, HER2– advanced breast cancer (ABC) presenting with visceral metastases or bone-only disease: A subgroup analysis of the MONALEESA-2 trial [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-22-16.