Phase II consolidation trial with anti-Lewis-Y monoclonal antibody (hu3S193) in platinum-sensitive ovarian cancer after a second remission.

OBJECTIVE: To investigate the efficacy and safety of hu3S193, a humanized anti-Lewis-Y monoclonal antibody, as a consolidation strategy in patients with platinum-sensitive recurrent epithelial ovarian cancer who achieved a second complete response after salvage platinum-doublet chemotherapy. METHODS: This single-arm phase II study accrued patients with recurrent epithelial ovarian cancer with Lewis-Y expression by immunohistochemistry who had achieved a second complete response after five to eight cycles of platinum-based chemotherapy. Patients received intravenous infusions of hu3S193, 30 mg/m2 every 2 weeks starting no more than 8 weeks after the last dose of chemotherapy and continuing for 12 doses, until disease progression, or unacceptable toxicity. The primary endpoint was progression-free survival of the second remission. Secondary objectives were safety and pharmacokinetics. RESULTS: Twenty-nine patients were enrolled. Most had a papillary/serous histology tumor (94%), stage III disease at diagnosis (75%), and five (17%) underwent secondary cytoreduction before salvage chemotherapy. Two patients were not eligible for efficacy but were considered for toxicity analysis. Eighteen patients (62%) completed the full consolidation treatment while nine patients progressed on treatment. At the time of analysis, 23 patients (85%) of the eligible population had progressed and seven of these patients (26%) had died. Median progression-free survival of the second remission was 12.1 months (95% CI: 10.6-13.9), with a 1-year progression-free survival of the second remission rate of 50.1%. The trial was terminated early since it was unlikely that the primary objective would be achieved. The most commonly reported treatment-related adverse events were nausea (55%) and vomiting (51%). CONCLUSIONS: Hu3S193 did not show sufficient clinical activity as consolidation therapy in patients with recurrent epithelial ovarian cancer who achieved a second complete response after platinum-based chemotherapy. TRIAL REGISTRATION: NCT01137071.

Pembrolizumab Plus Carboplatin and Paclitaxel as First-Line Therapy for Recurrent/Metastatic Head and Neck Squamous Cell Carcinoma (KEYNOTE-B10): A Single-Arm Phase IV Trial.

PURPOSE: Standard-of-care first-line treatment for recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC) is pembrolizumab plus platinum and fluorouracil (FU). However, FU is associated with potential challenges (continuous 4-day infusion, high administration costs, and cardiovascular and gastrointestinal toxicities), creating a clinical need for alternative chemotherapy combinations. We evaluated the efficacy and safety of first-line pembrolizumab plus carboplatin and paclitaxel for R/M HNSCC in the open-label, single-arm, phase IV KEYNOTE-B10 study (ClinicalTrials.gov identifier: NCT04489888). METHODS: Eligible adults had previously untreated, histologically or cytologically confirmed R/M HNSCC regardless of PD-L1 status, measurable disease per RECIST v1.1 by blinded independent central review (BICR), and an Eastern Cooperative Oncology Group performance status of 0 or 1. Patients received pembrolizumab 200 mg intravenously once every 3 weeks for ≤35 cycles and carboplatin AUC 5 mg/mL/min intravenously once every 3 weeks for ≤6 cycles and investigator's choice of paclitaxel 100 mg/m2 on days 1 and 8 or 175 mg/m2 on day 1, intravenously once every 3 weeks. The primary end point was objective response rate per RECIST v1.1 by BICR. RESULTS: Between October 27, 2020, and April 29, 2022, 149 patients were screened and 101 received treatment. As of February 20, 2023, the median follow-up was 18.9 months (range, 9.1-27.0). At this final analysis, 49 (49%) of 101 patients had an objective response (95% CI, 38.4 to 58.7), including seven patients (7%) with a confirmed complete response. Of the 101 treated patients, grade 3-5 and serious treatment-related adverse events occurred in 76 (75%) and 27 (27%), respectively. There were no new safety signals. CONCLUSION: Pembrolizumab plus carboplatin and paclitaxel showed promising antitumor activity and a manageable safety profile in first-line R/M HNSCC, suggesting this combination may be an alternative option for this patient population.

Prevalence of the DPYD variant (Y186C) in Brazilian individuals of African ancestry.

PURPOSE: The presence of deleterious variants of dihydropyrimidine-dehydrogenase gene (DPYD) is associated with 5-Fluorouracil toxicity. Most of the data are based on findings in Caucasian populations. The variant Y186C (rs115232898) is found almost exclusively in African populations and is related to low DPD function. Its prevalence may vary among African subpopulations and in African Americans. There is no information in other populations. Brazil has the biggest African population outside Africa. We studied for the first time the frequency of this mutation in African Brazilians. METHODS: We amplified exon 6 of DPYD extracted from genomic DNA of 79 healthy volunteers of genetically defined African ancestry from Southeast Brazil and 36 self-reported African descendants from Northeast Brazil in order to determine the prevalence of the variant Y186C in Brazilians of African ancestry. RESULTS: The variant Y186C was found in heterozygosity in two samples from Southeast (2.53%) and one from Northeast (2.77%) Brazil. Overall, the prevalence of this mutation in the 115 African Brazilians was 2.6%. CONCLUSIONS: The variant Y186C is prevalent among Brazilians of African ancestry and should be taken in account in targeted genotyping for fluoropyrimidine risk variants.

(13)C-uracil breath test to predict 5-fluorouracil toxicity in gastrointestinal cancer patients.

PURPOSE: Up to 30 % of patients undergoing 5-fluorouracil (5FU)-based chemotherapy experience severe toxicity. Dihydropyrimidine dehydrogenase (DPD) deficiency explains 36-61 % of cases. Predicting toxicity is an unmet challenge. Uracil breath test (UraBT) consists of measuring (13)CO2 in exhaled breath after ingestion of 2-(13)C-uracil to evaluate pyrimidine (and 5FU) catabolism. METHODS: We studied 33 gastrointestinal cancer patients previously exposed to 5FU: Thirteen had grade 3-4 and 20, grade 0-1 toxicity. The following tests were used to evaluate pyrimidine catabolism: (1) sequencing of three exons of DPYD; (2) plasma dihydrouracil/uracil ratio (UH2/U); and (3) UraBT. We tested the performance of UraBT to discriminate patients who had grade 0-1 toxicity versus grade 3-4 toxicity and patients with and without proven DPD deficiency. RESULTS: Of the thirteen patients, four grade 3-4 toxicity patients were proved to be DPD-deficient: Three had deleterious mutations (IVS14 + 1G>A in one; single nucleotide polymorphism 2846A>T in two), and one had low UH2/U ratio. Mean delta over baseline in 50 min (DOB50) significantly differed between groups. DOB50≤161.4 discriminated individuals with grade 3-4 versus grade 0-1 toxicity (sensitivity = 61.5 %; specificity = 85 %) and DPD-deficient versus non-DPD-deficient (sensitivity = 75 %; specificity = 85 %). CONCLUSION: UraBT has moderate accuracy in discriminating individuals who manifested severe toxicity from those who had mild or no toxicity to 5FU.