Lecanemab: Appropriate Use Recommendations

Lecanemab (Leqembi®) is approved in the United States for the treatment of Alzheimer's disease (AD) to be initiated in early AD (mild cognitive impairment [MCI] due to AD or mild AD dementia) with confirmed brain amyloid pathology. Appropriate Use Recommendations (AURs) are intended to help guide the introduction of new therapies into real-world clinical practice. Community dwelling patients with AD differ from those participating in clinical trials. Administration of lecanemab at clinical trial sites by individuals experienced with monoclonal antibody therapy also differs from the community clinic-based administration of lecanemab. These AURs use clinical trial data as well as research and care information regarding AD to help clinicians administer lecanemab with optimal safety and opportunity for effectiveness. Safety and efficacy of lecanemab are known only for patients like those participating in the phase 2 and phase 3 lecanemab trials, and these AURs adhere closely to the inclusion and exclusion criteria of the trials. Adverse events may occur with lecanemab including amyloid related imaging abnormalities (ARIA) and infusion reactions. Monitoring guidelines for these events are detailed in this AUR. Most ARIA with lecanemab is asymptomatic, but a few cases are serious or, very rarely, fatal. Microhemorrhages and rare macrohemorrhages may occur in patients receiving lecanemab. Anticoagulation increases the risk of hemorrhage, and the AUR recommends that patients requiring anticoagulants not receive lecanemab until more data regarding this interaction are available. Patients who are apolipoprotein E ε4 (APOE4) gene carriers, especially APOE4 homozygotes, are at higher risk for ARIA, and the AUR recommends APOE genotyping to better inform risk discussions with patients who are lecanemab candidates. Clinician and institutional preparedness are mandatory for use of lecanemab, and protocols for management of serious events should be developed and implemented. Communication between clinicians and therapy candidates or those on therapy is a key element of good clinical practice for the use of lecanemab. Patients and their care partners must understand the potential benefits, the potential harms, and the monitoring requirements for treatment with this agent. Culture-specific communication and building of trust between clinicians and patients are the foundation for successful use of lecanemab.

Tissue microarrey: a potential cost-effective approach for mismatch repair testing in colorectal cancer

BACKGROUND

Deficiencies in Mismatch Repair (MMR) proteins are one of the major pathways in the development of colorectal cancer (CRC). MMR status evaluation is recommended in every new CRC patient. However, this is not fully implemented due to high costs. Tissue microarray (TMA) enables allocating tissue cores from few specimens to a single paraffin block. The primary objective of this study was to evaluate the accuracy of TMA MMR immunohistochemistry (IHC) compared to whole slide. The secondary objective was to evaluate and validate automatic digital image analysis software in differentiating pathological and normal TMA cores.

METHODS

Pathological cores were defined if at least one MMR protein was unstained. Tumoral and normal tissue of 11 CRC patients with known MMR status was used to obtain 623 TMA cores. The MMR staining of each core was evaluated by a pathologist and compared to the whole slide result. Digital analysis software by 3DHistech Ltd. was used to identify cell nucleus and quantify nuclear staining in 323 tissue cores. To identifying pathological tissue, cores the cohort was divided into a test (N = 146 cores) and validation sets (N = 177 cores). A staining intensity score (SIS) was developed, and its performance compared to the pathologist review of each core and to the whole slide result.

RESULTS

Compared to the whole slide, the pathologist's assessment had 100% sensitivity (n/N = 112/112) and 100% specificity (n/N = 278/278) with 95% lower limit of 97 and 99% respectively. The area under the receiver operating characteristic (ROC) curve of SIS was 77%. A cutoff of 55 was obtained from the ROC curve. By implementing the cutoff in the validation dataset, the SIS had sensitivity and specificity of 98.2% [90.1-100%] and 58.5% [49.3-67.4%] respectively.

CONCLUSIONS

The MMR status of CRC can be evaluated in TMA tissue cores thus potentially reducing MMR testing costs. The SIS can be used as triage indicator during pathologic review.

TRIAL REGISTRATION

Institutional ethical approval was granted for the performance of this study (Emek Medical Center Ethics ID: EMC-19-0179).

Discrepancies between tumor genomic profiling and germline genetic testing

BACKGROUND

Tumor genomic profiling (TGP) often incidentally identifies germline pathogenic variants (PVs) associated with cancer predisposition syndromes. Methods used by somatic testing laboratories, including germline analysis, differ from designated germline laboratories that have optimized the identification of germline PVs. This study evaluated discrepancies between somatic and germline testing results, and their impact on patients.

PATIENTS AND METHODS

Chart reviews were carried out at a single institution for patients who had both somatic and designated germline genetic testing. Cases with discrepant results in which germline PVs were not detected by the somatic laboratory or in which variant classification differed are summarized.

RESULTS

TGP was carried out on 2811 cancer patients, 600 of whom also underwent designated germline genetic testing. Germline PVs were identified for 109 individuals. Discrepancies between germline genetic testing and tumor profiling reports were identified in 20 cases, including 14 PVs identified by designated germline genetic testing laboratories that were not reported by somatic testing laboratories and six variants with discrepant classifications between the designated germline and somatic testing laboratories. Three PVs identified by designated germline laboratories are targets for poly adenosine diphosphate-ribose polymerase (PARP) inhibitors and resulted in different treatment options. Of the PVs identified by designated germline laboratories, 60% (n = 12) were in genes with established associations to the patients' cancer, and 40% of the PVs were incidental. The majority (90%) of all discrepant findings, both contributory and incidental, changed management recommendations for these patients, highlighting the importance of comprehensive germline assessment.

CONCLUSIONS

Methods used by somatic laboratories, regardless of the inclusion of germline analysis, differ from those of designated germline laboratories for identifying germline PVs. Unrecognized germline PVs may harm patients by missing hereditary syndromes and targeted therapy opportunities (e.g. anti-programmed cell death protein 1 immunotherapy, PARP inhibitors). Clinicians should refer patients who meet the criteria for genetic evaluation regardless of somatic testing outcomes.

POS1342 DEPLETION OF KLRG1+ T CELLS IN A FIRST-IN-HUMAN CLINICAL TRIAL OF ABC008 IN INCLUSION BODY MYOSITIS (IBM)

Background

Inclusion body myositis (IBM), a relentlessly progressive autoimmune skeletal muscle disease, has no effective available pharmacological therapy. A prominent feature of IBM on microscopy is highly differentiated effector CD8+ cytotoxic T (Tc) cells invading non-necrotic myofibers [1]. These Tc cells, known to be relatively resistant to apoptosis, express markers including killer cell lectin-like receptor G1 (KLRG1) [2]. ABC008, a first-in-class humanized, afucosylated monoclonal antibody (mAb) specific for KLRG1, selectively depletes these highly differentiated Tc cells while sparing other blood cell populations, e.g., naïve, central memory, and regulatory T cells and B cells. ABC008 has been designed to treat diseases mediated by these Tc cells, including IBM and T-cell large granular lymphocytic leukemia (T-LGLL). IBM and rheumatoid arthritis overlap clinically with T-LGLL and share similar expansions of large granular lymphocytes (LGLs), which also express KLRG1. We report here our preliminary data from our ongoing trial of ABC008 in IBM (NCT04659031).

Objectives

Evaluate the safety, pharmacodynamics (PD), and pharmacokinetics (PK) of ABC008 administered subcutaneously (SC) in adults with IBM.

Methods

In this first-in-human, open-label, single ascending dose trial with 3 + 3 design evaluating ABC008 SC, eligible participants must have clinicopathologically defined, clinically defined, or probable IBM according to the European Neuromuscular Centre 2011 research diagnostic criteria [3] and an IBM Functional Rating Scale (IBMFRS) score ≤38. Four dose cohorts are planned: ABC008 0.1, 0.5, 2.0, and 5.0 mg/kg. PD, PK, safety, and disease severity assessments are performed pre-dose (Day 0) and during the 6-month follow-up period.

Results

Five of the 6 (83.3%) participants were male with baseline mean age = 65.7 years, mean IBM disease duration = 6.8 years, and mean IBMFRS score = 27.5 (Table 1). Each received a single dose of ABC008 SC: Cohorts 1 (C1) and 2 (C2) received 0.1 and 0.5 mg/kg and have completed 168 and 56 days of follow-up, respectively.

Table 1.

Baseline Demographics

Baseline CharacteristicsABC008 SC Treatment GroupsCohort 10.1 mg/kg SC (n=3)Cohort 20.5 mg/kg SC (n=3)ABC008 Overall (N=6)Age (years), mean ± SD64.0 ± 11.3667.3 ± 6.6665.7 ± 8.52Male sex, n (%)3 (100)2 (66.7)5 (83.3)Caucasian3 (100)3 (100)6 (100)Body Mass Index (kg/m2)28.5 ± 3.5828.3 ± 4.2528.4 ± 3.52Disease Duration (years), mean ± SD9.7 ± 5.973.9 ± 4.486.8 ± 5.70IBMFRS score, mean ± SD30.0 ± 4.0825.0 ± 6.1627.5 ± 5.80

Abbreviations: IBMFRS, Inclusion Body Myositis Functional Rating Scale; n or N, number; SC, subcutaneous; SD, standard deviation.

Maximum depletion of CD8+KLRG1+ cells for C1 and C2 ranged from 46-96% and 98-99%, respectively (Figure 1A), with depletion evident by the next assessment on Day 1. Recovery in C1 began at Day 84 with Day 168 depletion at 29-71%. Other hematologic parameters generally were stable (e.g., T regulatory and B cells). CD8+CD57+ LGLs, mostly KLRG1+, were also depleted (Figure 1B). Preliminary PK showed that ABC008 SC displays a long absorption phase and slow clearance properties typical of mAb therapies. No severe adverse events (AEs) or discontinuations due to AEs have been reported. One unrelated serious AE of fall with muscle tear in a C1 participant with a prior history of falls occurred.

Figure 1.

Key pharmacodynamic parameters in Study ABC008-IBM-101. Baseline and change (A) of KLRG1+CD8+ T cells and (B) CD8+CD57+ large granular lymphocytes (LGLs). C1 and C2 are Cohorts 1 and 2; P1, P2, and P3 are Participants 1, 2, and 3.

Conclusion

In study participants with IBM, single SC doses of 0.1 and 0.5 mg/kg of ABC008 resulted in the depletion of CD8+KLRG1+ cells and CD8+CD57+ LGLs with clear evidence of a dose response for KLRG1+ T cell depletion and no apparent safety signals. Based on these results, a study evaluating ABC008 for the treatment of T-LGLL is planned.

References

[1]Engel AG, et al. Ann Neurol. 1984;16:209-15.

[2]Greenberg SA, et al. Brain. 2016;139:1348-60.

[3]Rose MR, et al. Neuromuscul Disord. 2013;23:1044-55.

Disclosure of Interests

Niti Goel Shareholder of: UCB, Abcuro, Inc, Employee of: Abcuro, Inc, Merrilee Needham Consultant of: Abcuro, Inc, Grant/research support from: Abcuro, Inc, Dulce Soler-Ferran Shareholder of: Abcuro, Inc, Employee of: Abcuro, Inc, Monette M. Cotreau Consultant of: Abcuro, Inc, Jorge Escobar Shareholder of: Abcuro, Employee of: Abcuro, Steven Greenberg Shareholder of: Abcuro, Inc, Consultant of: Abcuro, Inc

Response to omalizumab using patient enrichment criteria from trials of novel biologics in asthma

Background

Recent efficacy studies of asthma biologics have included highly enriched patient populations. Using a similar approach, we examined factors that predict response to omalizumab to facilitate selection of patients most likely to derive the greatest clinical benefit from therapy.

Methods

Data from two phase III clinical trials of omalizumab in patients with allergic asthma were examined. Differences in rates of asthma exacerbations between omalizumab and placebo groups during the 16‐week inhaled corticosteroid (ICS) dose‐stable phase were evaluated with respect to baseline blood eosinophil counts (eosinophils <300/μL [low] vs ≥300/μL [high]) and baseline markers of asthma severity (emergency asthma treatment in prior year, asthma hospitalization in prior year, forced expiratory volume in 1 second [FEV₁; FEV₁ <65% vs ≥65% predicted], inhaled beclomethasone dipropionate dose [<600 vs ≥600 μg/day], and long‐acting beta‐agonist [LABA] use [yes/no]).

Results

Adults/adolescents (N = 1071) were randomized to receive either omalizumab (n = 542) or placebo (n = 529). In the 16‐week ICS dose‐stable phase, rates of exacerbations requiring ≥3 days of systemic corticosteroid treatment were 0.066 and 0.147 with omalizumab and placebo, respectively, representing a relative rate reduction in omalizumab‐treated patients of 55% (95% CI, 32%‐70%; P = .002). For patients with eosinophils ≥300/μL or with more severe asthma, this rate reduction was significantly more pronounced.

Conclusion

In patients with allergic asthma, baseline blood eosinophil levels and/or clinical markers of asthma severity predict response to omalizumab.

Intracranial nonjugular venous pathways: a possible compensatory drainage mechanism

BACKGROUND AND PURPOSE

The IJVs are considered to be the main pathway draining the intracranial venous system. There is increasing evidence for the existence of alternative venous pathways. Studies using extracranial sonography techniques have demonstrated a nonjugular venous system. In the current study, we used MR images to investigate the NJV drainage system and its components (vertebral plexus, pterygopalatine plexus). The exact visualization and measurement of the intracranial NJVs could be of diagnostic importance and may have clinical importance.

MATERIALS AND METHODS

A total of 64 participants with no history of neurologic disease were included in the study. All participants underwent scanning with a 2D time-of-flight, multisection sequence in the supine position. Image processing software was developed to identify and quantify the size of the IJVs and NJVs in the plane of the internal JF. For evaluation of software accuracy, all images were reviewed by a neuroradiologist experienced in neurovascular imaging preprocessing and postprocessing.

RESULTS

The CSA of the NJVs correlated inversely with the CSA of the IJVs (r(2) = 0.25; P < .0001). An inverse correlation was also significant when comparing IJV with NJV components (vertebral plexus: r(2) = 0.19; P = .0004; pterygopalatine plexus: r(2) = 0.11; P = .0069). Furthermore, only NJV cumulative CSA correlated inversely with participant age (r(2) = 0.2; P = .0002).

CONCLUSIONS

Our study indicates that the NJVs might serve as a compensatory drainage mechanism in the intracranial compartment. This mechanism appears less significant as the age of the patient progresses.

Effect of anaesthetic technique and other perioperative factors on cancer recurrence

Surgical excision is the mainstay of treatment for potentially curable solid tumours. Metastatic disease is the most important cause of cancer-related death in these patients. The likelihood of tumour metastases depends on the balance between the metastatic potential of the tumour and the anti-metastatic host defences, of which cell-mediated immunity, and natural killer cell function in particular, is a critical component. It is increasingly recognized that anaesthetic technique and other perioperative factors have the potential to effect long-term outcome after cancer surgery. Surgery can inhibit important host defences and promote the development of metastases. Anaesthetic technique and drug choice can interact with the cellular immune system and effect long-term outcome. The potential effect of i.v. anaesthetics, volatile agents, local anaesthetic drugs, opiates, and non-steroidal anti-inflammatory drugs are reviewed here. There is particular interest at present in the effect of regional anaesthesia, which appears to be beneficial. Retrospective analyses have shown an outcome benefit for paravertebral analgesia for breast cancer surgery and epidural analgesia for prostatectomy. Blood transfusion, pain, stress, and hypothermia are other potentially important perioperative factors to consider.