Alirocumab in Pediatric Patients With Heterozygous Familial Hypercholesterolemia: A Randomized Clinical Trial.

Importance: Many pediatric patients with heterozygous familial hypercholesterolemia (HeFH) cannot reach recommended low-density lipoprotein cholesterol (LDL-C) concentrations on statins alone and require adjunct lipid-lowering therapy (LLT); the use of alirocumab in pediatric patients requires evaluation. Objective: To assess the efficacy of alirocumab in pediatric patients with inadequately controlled HeFH. Design, Setting, and Participants: This was a phase 3, randomized clinical trial conducted between May 2018 and August 2022 at 43 centers in 24 countries. Pediatric patients aged 8 to 17 years with HeFH, LDL-C 130 mg/dL or greater, and receiving statins or other LLTs were included. Following consecutive enrollment into dosing cohorts, 25 of 99 patients screened for dosing every 2 weeks (Q2W) failed screening; 25 of 104 patients screened for dosing every 4 weeks (Q4W) failed screening. A total of 70 of 74 Q2W patients (95%) and 75 of 79 Q4W patients (95%) completed the double-blind period. Interventions: Patients were randomized 2:1 to subcutaneous alirocumab or placebo and Q2W or Q4W. Dosage was based on weight (40 mg for Q2W or 150 mg for Q4W if <50 kg; 75 mg for Q2W or 300 mg for Q4W if ≥50 kg) and adjusted at week 12 if LDL-C was 110 mg/dL or greater at week 8. After the 24-week double-blind period, patients could receive alirocumab in an 80-week open-label period. Main Outcomes and Measures: The primary end point was percent change in LDL-C from baseline to week 24 in each cohort. Results: Among 153 patients randomized to receive alirocumab or placebo (mean [range] age, 12.9 [8-17] years; 87 [56.9%] female), alirocumab showed statistically significant reductions in LDL-C vs placebo in both cohorts at week 24. Least squares mean difference in percentage change from baseline was -43.3% (97.5% CI, -56.0 to -30.7; P < .001) Q2W and -33.8% (97.5% CI, -46.4 to -21.2; P < .001) Q4W. Hierarchical analysis of secondary efficacy end points demonstrated significant improvements in other lipid parameters at weeks 12 and 24 with alirocumab. Two patients receiving alirocumab Q4W experienced adverse events leading to discontinuation. No significant difference in adverse event incidence was observed between treatment groups. Open-label period findings were consistent with the double-blind period. Conclusions and Relevance: The findings in this study indicate that alirocumab Q2W or Q4W significantly may be useful for reducing LDL-C and other lipid parameters and be well tolerated in pediatric patients with HeFH inadequately controlled with statins. Trial Registration: ClinicalTrials.gov Identifier: NCT03510884.

Comparison of histopathology and RT-qPCR amplification of guanylyl cyclase C for detection of colon cancer metastases in lymph nodes.

AIMS: In colorectal cancer (CRC), the presence of lymph node (LN) metastases is an important prognostic factor. Approximately 20% of patients diagnosed as having node-negative (pN0) CRC will relapse. Pathological nodal stage misclassification due to sampling error resulting from the small volume of tissue tested has been proposed to explain this recurrence rate in pN0 patients. The authors compared the assessment of node positivity by histopathology (HP) with a molecular method which can accommodate larger tissue volumes. METHODS: Detection rate of guanylyl cyclase C (GCC) mRNA was determined in 1,495 LNs from 99 CRC patients. Using a subset of 647 LNs, multiple levels of HP analysis were compared with GCC mRNA molecular detection. Finally, clinicopathological factors were correlated with the molecular detection of GCC and clinical outcome in 123 patients with pN0 colon cancer. RESULTS: GCC mRNA was detected in 8.0% of the 560 nodes initially identified as HP-negative, whereas two repeat HP examinations detected 3.0% of these cases. In HP-positive LNs, the GCC mRNA detection rate was 90% (78/87) when half-LN were tested. Testing the entire LN remaining after HP by GCC increased the detection rate of HP-positive LNs to 95% (p=0.027). In comparison, 75% (65/87) and 92% (80/87) of the LN positive by clinical HP remained positive when one or two subsequent sections were examined by HP. Finally, patients with pN0 disease who were GCC-positive exhibited an earlier time of recurrence (hazard ratio, 3.54; 95% CI 1.40 to 8.98; p=0.0077). CONCLUSIONS: Molecular detection of tumour cells in LNs may have prognostic value in identifying patients diagnosed as having pN0 colon cancer who will relapse following surgery.

Analytical performance of a qRT-PCR assay to detect guanylyl cyclase C in FFPE lymph nodes of patients with colon cancer.

Up to 30% of patients with stage II (pN0) colon cancer develop recurrences, suggesting that the presence of lymph node (LN) metastases escaped detection at histopathologic staging. A simple way to overcome this limitation and to improve staging accuracy is to use reverse transcription-polymerase chain reaction (RT-PCR) to examine a larger fraction or an entire specimen. The Guanylyl cyclase C (GCC) gene is uniquely expressed in apical cells of the gastrointestinal tract. Its expression in colon cancer cells and metastases is conserved. Therefore, detection of GCC mRNA in LNs has been shown to be indicative of the presence of colon cancer metastases. As the current processing of LNs involves formalin fixation and paraffin embedding, we developed a method for extracting RNA from formalin-fixed paraffin-embedded LN specimens and detecting GCC mRNA by quantitative RT-PCR. The assay has a dynamic range of 5 logs, an average amplification efficiency of 98.4% (95% confidence interval, 96.6-100.3), a reaction linearity of 0.998 (95% confidence interval, 0.997-0.999), and also intraplate and interplate CVs of <1% and <5%, respectively. The test specificity was 98% with LNs collected from patients affected by conditions other than colon cancer (n=380). Sensitivity was 97% for patients with stage III colon cancer (n=34), whereas 35% of patients with stages I and II disease (n=51) had at least 1 GCC mRNA-positive LN. The high specificity of GCC mRNA suggests that routine utilization of the quantitative RT-PCR test has the potential to improve the detection of colon cancer metastases in LNs.