Pharmacogenetic testing in oncology: a Brazilian perspective

Comparison of dose-dense vs. 3-weekly paclitaxel and carboplatin in the first-line treatment of ovarian cancer in a propensity score-matched cohort

Background

Benefit of carboplatin and dose-dense weekly paclitaxel (ddCT) in first line treatment of ovarian cancer patients has been different in Western and Asian studies. In the present study we compare progression-free survival (PFS) of ddCT to three-weekly carboplatin and paclitaxel (CT) in first-line treatment of ovarian carcinoma in a single institution in a Western population.

Materials and methods

We conducted a retrospective review of medical records from patients with ovarian carcinoma treated in a tertiary cancer center from 2007 to 2018. All patients treated with ddCT or CT in the first-line setting were included. Patients who received first-line bevacizumab were not included. PFS and overall survival (OS) were compared in a propensity score-matched cohort to address selection bias. Patients were matched according to age, ECOG performance status, CA 125, FIGO stage, residual disease, and histological subtype, in a 1:2 ratio.

Results

Five hundred eighty-eight patients were eligible for propensity score matching, the final cohort consisted of 69 patients treated with ddCT and 138 CT group. Baseline characteristics were well-balanced. After a median follow-up of 65.1 months, median PFS was 29.3 vs 20.0 months, favouring ddCT treatment (p = 0.035). In the multivariate cox regression ddCT showed a 18% lower risk of progression (HR 0.82, 95% CI 0.68–0.99, p = 0.04). Overall survival data is immature, but suggested better outcomes for ddCT (not reached versus 78.8 months; p = 0.07).

Conclusion

Our retrospective study has shown superior PFS of ddCT over CT regimen in first-line treatment of ovarian carcinoma in a Western population not treated with bevacizumab.

Pharmacogenomic landscape of VIP genetic variants in Jordanian Arabs and comparison with worldwide populations

The pharmacogenomics has lately become a focal field of research that investigates the influence of genetic variations of drug-metabolizing enzymes and their receptors and downstream proteins on the interindividual variability in response to medications and adverse drug reactions. Therefore, it is significantly important to study and analyze the variations in drug response between different ethnic groups and populations. The current study aimed to detect the distribution of the genotype and allele frequencies in several very important pharmacogenetic (VIP) gene polymorphisms in the Jordanian population of Arab descent. This study involved 500 unrelated Jordanian individuals of Arab descent. A total of 65 VIP variants located within 33 candidate genes were randomly selected from the PharmGKB database and genotyped using the MassARRAY (iPLEX GOLD) system. The chi-square test was used to evaluate the significant differences of minor allele and genotype frequencies between the Jordanian and other populations including CHE, ASW, CEU, CHB, CDX, GIH, GBR, JPT, LWK, MXL, TSI, YRI, CAR, and ACB. This study revealed six variants were not in Hardy Weinberg equilibrium (HWE) (P-value > 0.05) and ten SNPs showed monomorphic features. Most of the remaining forty-nine variant frequencies were significantly different from the compared ethnic groups (P-value < 0.05). The results of this study may be helpful to develop safer treatment by applying the concept of personalized medicine based on the profile of VIP pharmacogene variants of the Jordanian population of Arab descent.

Pharmacogenomic biomarker information differences between drug labels in the United States and Hungary: implementation from medical practitioner view

Pharmacogenomic biomarker availability of Hungarian Summaries of Product Characteristics (SmPC) was assembled and compared with the information in US Food and Drug Administration (FDA) drug labels of the same active substance (July 2019). The level of action of these biomarkers was assessed from The Pharmacogenomics Knowledgebase database. From the identified 264 FDA approved drugs with pharmacogenomic biomarkers in drug label, 195 are available in Hungary. From them, 165 drugs include pharmacogenomic data disposing 222 biomarkers. Most of them are metabolizing enzymes (46%) and pharmacological targets (41%). The most frequent therapeutic area is oncology (37%), followed by infectious diseases (12%) and psychiatry (9%) (p < 0.00001). Most common biomarkers in Hungarian SmPCs are CYP2D6, CYP2C19, estrogen and progesterone hormone receptor (ESR, PGS). Importantly, US labels present more specific pharmacogenomic subheadings, the level of action has a different prominence, and offer more applicable dose modifications than Hungarians (5% vs 3%). However, Hungarian SmPCs are at 9 oncology drugs stricter than FDA, testing is obligatory before treatment. Out of the biomarkers available in US drug labels, 62 are missing completely from Hungarian SmPCs (p < 0.00001). Most of these belong to oncology (42%) and in case of 11% of missing biomarkers testing is required before treatment. In conclusion, more factual, clear, clinically relevant pharmacogenomic information in Hungarian SmPCs would reinforce implementation of pharmacogenetics. Underpinning future perspective is to support regulatory stakeholders to enhance inclusion of pharmacogenomic biomarkers into Hungarian drug labels and consequently enhance personalized medicine in Hungary.