Comparative Analysis of the Suspected Heparin-Induced Thrombocytopenia Level in Korea

Untoward immune effects of modern medication

Immune-related adverse events (irAEs) represent an increasingly concerning challenge in the assessment of biopharmaceutical products. In contrast to historically rare allergic reactions associated with small chemical drugs, contemporary biotherapeutics exhibit a significantly higher morbidity of irAEs, because of their complex structure and comprehensive mechanisms of action. While the immunogenicity of protein-based compounds is associated with the induction of anti-drug antibodies, the pathogenesis of irAEs in advanced biologics, such as cell and gene therapy, remains to be further delineated. In the current study, I present an updated profile regarding the untoward immune effects of medications, covering various material categories systematically, with the underlying mechanisms to inspire risk mitigation in biopharmaceutical development and application.

Dexamethasone Intravitreal Implant for the Treatment of Macular Edema Following Retinal Vein Occlusion: Post Hoc Analysis of Post-Marketing Surveillance Data in the Real-World Setting in Korea

Purpose

To supplement established efficacy and safety data, this analysis evaluated the real-world use of dexamethasone (DEX) intravitreal implant 700 µg for retinal vein occlusion (RVO)-related macular edema in an Asian population and baseline factors potentially associated with DEX implant efficacy.

Patients and Methods

A prospective, observational, post-marketing surveillance study was conducted at 38 sites in South Korea in patients consecutively presenting with macular edema following branch or central RVO (BRVO, CRVO), and administered a first DEX implant. Follow-up visits and subsequent DEX or other therapies conformed with local practice. Outcome measures included best-corrected visual acuity (BCVA), change in BCVA from baseline, responder rates, and adverse events. Associations between baseline characteristics and BCVA gains were evaluated. Month-1, -2, -4, and -6 visit analysis windows were established.

Results

In all, 700 patients (79.1% BRVO, 20.9% CRVO) received 1.12 DEX implants (mean) and were followed for 101.5 days (standard deviation, 51.7); 90% received a single implant. Among patients with analyzable data, mean BCVA improved from baseline with peak changes in Month 2 of −0.193 and −0.212 LogMAR, (P < 0.0001) and remained significant in the BRVO subgroup at the Month 4 and 6 windows (P < 0.0001 and P = 0.0039, respectively). Treatment-naïve patients experienced greater BCVA increases. The proportion of patients with stable/improved BCVA tended to decrease after Month 2 through Month 6 and the decline was greater in the CRVO subgroup. At the Month-2 window, ≥1-, 2- and 3-line increases were positively associated with younger age, worse baseline BCVA, and treatment naivety. The most common adverse event was increased intraocular pressure.

Conclusion

In the real-world clinical setting in South Korea, DEX implant improved visual acuity and had a favorable safety profile similar to that reported in randomized controlled trials and observational European and North American studies. These data further support the value of DEX implant as a treatment option for RVO.

ClinicalTrials.gov Identifier

NCT01976650. Date of registration: November 6, 2013.

Treatment of Intracranial Infection Caused by Methicillin-Resistant Staphylococcus epidermidis with Linezolid Following Poor Outcome of Vancomycin Therapy: A Case Report and Literature Review

The pharmacokinetic/pharmacodynamic (PK/PD) parameter for evaluating the efficacy of vancomycin is now recommended to target an AUC/MIC (area under the curve, AUC; minimum inhibitory concentration, MIC) ratio of 400 to 600, and trough concentration should not be used as a substitute. We report a case of intracranial infection caused by methicillin-resistant Staphylococcus epidermidis (MRSE), which was sensitive to vancomycin (MIC=2µg/mL) and linezolid (MIC=4µg/mL). The trough concentration of vancomycin in serum was 18.3 µg/mL, and the vancomycin concentration in CSF was 5.0 µg/mL, all within normal range. However, the AUC/MIC ratio was calculated to be 125 mg·h·L^-1, unable to reach target AUC/MIC. Vancomycin was replaced with linezolid after 36 days of treatment due to poor outcome, and the patient was eventually cured. Further, 23 cases of intracranial methicillin-resistant Staphylococcus aureus (MRSA) or methicillin-resistant coagulase-negative Staphylococcus (MRCoNS) infections were reported, of which 1 case with MRSA had a vancomycin MIC of 1 µg/mL, while the remaining 22 cases had vancomycin MICs >1 µg/mL. The linezolid-containing regimen was used after drug susceptibility results or if the initial treatment failed, leading to recovery in 19 patients, microbial clearance in 3 patients, and treatment failure in 1 case. In conclusion, vancomycin dosing should be based on AUC-guided dosing and monitoring. When the vancomycin MIC of MRSA/MRCoNS is >1 µg/mL, the target AUC/MIC may not be achieved. In such cases, linezolid can effectively be considered as a good alternative to vancomycin.

Linezolid is safe on platelet count for AML patients during myelosuppression after consolidation chemotherapy

BACKGROUND

Patients with acute myeloid leukaemia (AML) often develop severe infections during myelosuppression after chemotherapy. Linezolid is an appropriate choice for these patients when coverage of positive bacteria is needed. An important side effect of linezolid is linezolid-induced thrombocytopenia; so, the safety of linezolid for AML patients in myelosuppression is of concern. No study has focused on platelets in these patients.

METHODS

We reviewed 1356 AML patients who received consolidation chemotherapy in our hospital during January 2009 and June 2019. Among them, 36 patients were treated with linezolid and 41 with vancomycin. We counted the days of platelet count <20*10E9/L, <50*10E9/L, the lowest platelet count, total quantity of platelet transfusion and clinical bleeding events of these patients, to evaluate the safety of linezolid during myelosuppression in AML patients.

RESULTS

The days of platelet count <20*10E9/L in the linezolid group and vancomycin group were 6.2 ± 2.5 days and 6.7 ± 2.9 days, and the days of platelet count <50*10E9/L in the linezolid group and vancomycin group were 10.9 ± 3.6 days and 11.7 ± 4.0 days, respectively; there was no significant difference between the two groups. No life-threatening severe bleeding events occurred in either group.

CONCLUSION

This retrospective clinical study suggests that it is safe to manage AML patients in complete remission during myelosuppression after standard consolidation chemotherapy with idarubicin and cytarabine, with about 7 days of linezolid therapy.

Developing a multi-center clinical data mart of ACEI and ARB for real-world evidence (RWE)

Background

Randomized controlled trials can be expensive and time-consuming, leading to medical researchers utilizing real-world evidence (RWE) based on already-collected data. We aimed to conduct various RWE studies on angiotensin-converting enzyme inhibitors (ACEI) and angiotensin II receptor blocker (ARB), commonly used as first-line therapy for blood pressure, and to develop a multi-center clinical data mart (CDM) of ACEI/ARB for various clinical purposes.

Methods

Data from electronic medical records of St. Mary’s Hospital and the Seoul National University Hospital were collected. We obtained blood and urine test results of patients within the 30 days prior to their first prescription of ACEI or ARB, as well as the first date of diagnosis and presence of various chronic and cardiovascular diseases using the International Classification of Diseases-10 classification. One researcher managed data quality and collation for each hospital in order to facilitate patient anonymity. When results were unclear, the responsible investigator for each hospital attempted to resolve ambiguities by direct chart review.

Results

A total of 102,333 patients who were prescribed ACEI or ARB for the first time were included (21,481 ACEI, 80,551 ARB, and 301 both). Our ACEI/ARB-CDM included short-term studies (within 12 months) to observe changes in various blood or urinary laboratory test values after the initial prescription of ACEI or ARB and long-term studies to confirm the incidence of various diseases.

Conclusion

We established a CDM of RWE for ACEI/ARB prescription, which included various clinical studies. As we accumulate experience in this process, we expect that the use of RWE research will grow and develop.

Risk factors for linezolid-induced thrombocytopenia in patients without haemato-oncologic diseases

This study aimed to describe the occurrence and to evaluate the predictive factors of thrombocytopenia caused by parenteral linezolid in hospitalised patients without haemato-oncologic diseases. Using electronic medical records, a retrospective safety evaluation was performed among all hospitalised adult patients who received parenteral linezolid therapy between January 2005 and June 2016. Of all identified 264 patients with an average age of 63.4 (SD 15.8) years, thrombocytopenia occurred at a rate of 29.2% after an average of 11.2 (SD 7.4) days of the initiation of linezolid therapy. Significant predictive factors for thrombocytopenia included the duration of linezolid therapy longer than or equal to 7 days (adjusted odds ratios [ORs] 7.25, 19.51 and 28.80; 95% confidence intervals [CIs] 1.92-27.38, 4.76-79.95 and 6.48-127.92 for 7-13 days, 14-20 days and ≥21 days, respectively; P < 0.01 for all values), baseline platelet count <150 × 10³ /mm³ (adjusted OR, 5.08; 95% CI, 2.06-12.55; P < 0.001), creatinine clearance <30 mL/min (adjusted OR, 4.19; 95% CI, 1.59-11.06; P = 0.004) and concurrent low-dose aspirin therapy (adjusted OR, 2.99; 95% CI, 1.26-7.08; P = 0.013). Baseline platelet count less than 150 × 10³ /mm³ was an independent predictor of early-onset (≤6 days) thrombocytopenia (adjusted OR, 5.07; 95% CI, 1.46-17.58; P = 0.011). Closer monitoring of platelet count is required in patients who receive parenteral linezolid therapy for 7 days or more, and have low baseline platelet counts or impaired renal function.

Real-world Evidence versus Randomized Controlled Trial: Clinical Research Based on Electronic Medical Records

Real-world evidence (RWE) and randomized control trial (RCT) data are considered mutually complementary. However, compared with RCT, the outcomes of RWE continue to be assigned lower credibility. It must be emphasized that RWE research is a real-world practice that does not need to be executed as RCT research for it to be reliable. The advantages and disadvantages of RWE must be discerned clearly, and then the proper protocol can be planned from the beginning of the research to secure as many samples as possible. Attention must be paid to privacy protection. Moreover, bias can be reduced meaningfully by reducing the number of dropouts through detailed and meticulous data quality management. RCT research, characterized as having the highest reliability, and RWE research, which reflects the actual clinical aspects, can have a mutually supplementary relationship. Indeed, once this is proven, the two could comprise the most powerful evidence-based research method in medicine.