Andrew R. Clamp

Multi-Maintenance Olaparib Therapy in Relapsed, Germline BRCA1/2 -Mutant High-Grade Serous Ovarian Cancer (MOLTO): A Phase II Trial

Abstract Purpose: A single maintenance course of a PARP inhibitor (PARPi) improves progression-free survival (PFS) in germline BRCA1/2-mutant high-grade serous ovarian cancer (gBRCAm-HGSOC). The feasibility of a second maintenance course of PARPi was unknown. Patients and Methods: Phase II trial with two entry points (EP1, EP2). Patients were recruited prior to rechallenge platinum. Patients with relapsed, gBRCAm-HGSOC were enrolled at EP1 if they were PARPi-naïve. Patients enrolled at EP2 had received their first course of olaparib prior to trial entry. EP1 patients were retreated with olaparib after RECIST complete/partial response (CR/PR) to platinum. EP2 patients were retreated with olaparib ± cediranib after RECIST CR/PR/stable disease to platinum and according to the platinum-free interval. Co-primary outcomes were the proportion of patients who received a second course of olaparib and the proportion who received olaparib retreatment for ≥6 months. Functional homologous recombination deficiency (HRD), somatic copy-number alteration (SCNA), and BRCAm reversions were investigated in tumor and liquid biopsies. Results: Twenty-seven patients were treated (EP1 = 17, EP2 = 10), and 19 were evaluable. Twelve patients (63%) received a second course of olaparib and 4 received olaparib retreatment for ≥6 months. Common grade ≥2 adverse events during olaparib retreatment were anemia, nausea, and fatigue. No cases of MDS/AML occurred. Mean duration of olaparib treatment and retreatment differed (12.1 months vs. 4.4 months; P < 0.001). Functional HRD and SCNA did not predict PFS. A BRCA2 reversion mutation was detected in a post-olaparib liquid biopsy. Conclusions: A second course of olaparib can be safely administered to women with gBRCAm-HGSOC but is only modestly efficacious. See related commentary by Gonzalez-Ochoa and Oza, p. 2563

Pazopanib and Fosbretabulin in recurrent ovarian cancer (PAZOFOS): A multi-centre, phase 1b and open-label, randomised phase 2 trial

Vascular co-option is a resistance mechanism to anti-angiogenic agents, but combinations of anti-vascular agents may overcome this resistance. We report a phase 1b and randomised phase 2 trial to determine the safety and efficacy of pazopanib with fosbretabulin. Eligible patients had recurrent, epithelial ovarian cancer with a platinum-free interval (PFI) of 3 to 12 months. Patients were stratified according to PFI (>6 versus ≤6 months) and prior bevacizumab use. Twelve patients were treated in the phase 1b. Commonest grade ≥ 2 adverse events (AEs) were hypertension (100%), neutropenia (50%), fatigue (50%), vomiting (50%). There was one DLT (grade 3 fatigue). The recommended phase 2 dose level was fosbretabulin 54 mg/m It remains unclear whether pazopanib with with fosbretabulin is an efficacious regimen to treat epithelial ovarian cancer. Effective cardiac risk mitigation is needed to increase the tolerability and maximize patient safety in future trials.

Homologous recombination deficiency in newly diagnosed FIGO stage III/IV high-grade epithelial ovarian cancer: a multi-national observational study

Olaparib plus bevacizumab maintenance therapy improves survival outcomes in women with newly diagnosed, advanced, high-grade ovarian cancer with a deficiency in homologous recombination. We report data from the first year of routine homologous recombination deficiency testing in the National Health Service (NHS) in England, Wales, and Northern Ireland between April 2021 and April 2022. The Myriad myChoice companion diagnostic was used to test DNA extracted from formalin-fixed, paraffin-embedded tumor tissue in women with newly diagnosed International Federation of Gynecology and Obstetrics (FIGO) stage III/IV high-grade epithelial ovarian, fallopian tube, or primary peritoneal cancer. Tumors with homologous recombination deficiency were those with a The myChoice assay was performed on 2829 tumors. Of these, 2474 (87%) and 2178 (77%) successfully underwent This is the largest real-world evaluation of homologous recombination deficiency testing in newly diagnosed FIGO stage III/IV high-grade epithelial ovarian, fallopian tube, or primary peritoneal cancer. It is important to select tumor tissue with adequate tumor content and quality to reduce the risk of assay failure. The rapid uptake of testing across England, Wales, and Northern Ireland demonstrates the power of centralized NHS funding, center specialization, and the NHS Genomic Laboratory Hub network.

Once daily cediranib and weekly paclitaxel to prevent malignant bowel obstruction in at-risk patients with platinum-resistant ovarian cancer (CEBOC): a single-arm, phase II safety trial

Cytotoxic chemotherapy for ovarian cancer can be augmented by co-administration of vascular endothelial growth factor inhibitors but these are contraindicated in patients with bowel obstruction due to the risk of gastrointestinal perforation. We evaluated the safety and feasibility of paclitaxel plus cediranib to treat patients with platinum-resistant ovarian cancer at risk of malignant bowel obstruction. A phase II trial included eligible patients between March 2018 and February 2021, identified by clinical symptoms and radiographic risk factors for malignant bowel obstruction. Cediranib (20 mg/day) was added to paclitaxel (70 mg/m Thirty patients were recruited. Of these, 12 received paclitaxel alone and 17 received paclitaxel and cediranib in combination. One patient died before starting treatment. No patient developed a grade 3-5 gastrointestinal perforation or fistula (one sided 95% confidence interval (CI) upper limit 0.16). One patient required hospitalization for bowel obstruction but recovered with conservative management. The most common cediranib-related grade ≥3 adverse events were fatigue (3/17), diarrhorea (2/17), and hypomagnesemia (2/17). Relative dose intensity for paclitaxel was 90% (interquartile range (IQR) 85-100%; n=29) and for cediranib 88% (IQR 76-93%; n=17). The objective response in patients who received paclitaxel and cediranib was 65.0% (one complete and 10 partial responses). Median progression-free survival was 6.9 months (95% CI 4.4-11.5 months; n=17) and overall survival was 19.4 months (95% CI 10.1-20.4 months; n=17). Median follow-up was 12.4 months (8.9-not reached; n=17). The unexpectedly high withdrawal rate during paclitaxel alone, before introducing cediranib, meant we were unable to definitely conclude that paclitaxel plus cediranib did not cause gastrointestinal perforation or fistula. The regimen was however tolerated. EudraCT 2016-004618-93.

Molecular Results and Potential Biomarkers Identified from the Phase 3 MILO/ENGOT-ov11 Study of Binimetinib versus Physician Choice of Chemotherapy in Recurrent Low-Grade Serous Ovarian Cancer

Abstract Purpose: We present the results of a post hoc tumor tissue analysis from the phase 3 MILO/ENGOT-ov11 study (NCT01849874). Patients and Methods: Mutation/copy-number analysis was performed on tissue obtained pre-randomization. The Kaplan–Meier method was used to estimate progression-free survival (PFS). Unbiased univariate analysis, Cox regression, and binary logistic regression were used to test associations between mutation status and outcomes, including PFS and binary response by local RECIST 1.1. Results: MILO/ENGOT-ov11 enrolled 341 patients, ranging in age from 22 to 79, from June, 2013 to April, 2016. Patients were randomized 2:1 to binimetinib or physician's choice of chemotherapy (PCC). The most commonly altered gene was KRAS (33%). In 135 patients treated with binimetinib with response rate (RR) data, other detected MAPK pathway alterations included: NRAS (n = 11, 8.1%), BRAF V600E (n = 8, 5.9%), RAF1 (n = 2, 1.5%), and NF1 (n = 7, 5.2%). In those with and without MAPK pathway alterations, the RRs with binimetinib were 41% and 13%, respectively. PFS was significantly longer in patients with, compared with those without, MAPK pathway alterations treated with binimetinib [HR, 0.5; 95% confidence interval (CI) 0.31–0.79]. There was a nonsignificant trend toward PFS improvement in PCC-treated patients with MAPK pathway alterations compared with those without (HR, 0.82; 95% CI, 0.43–1.59). Conclusions: Although this hypothesis-generating analysis is limited by multiple testing, higher RRs and longer PFS were seen in patients with low-grade serous ovarian cancer (LGSOC) treated with binimetinib, and to a lesser extent in those treated with PCC, who harbored MAPK pathway alterations. Somatic tumor testing should be routinely considered in patients with LGSOC and used as a future stratification factor.

Germline BRCA1/2 status and chemotherapy response score in high-grade serous ovarian cancer

Abstract Background High-grade serous ovarian cancer (HGSOC) can be treated with platinum-based neoadjuvant chemotherapy (NACT) and delayed primary surgery (DPS). Histopathological response to NACT can be assessed using Böhm’s chemotherapy response score (CRS). We investigated whether germline BRCA1/2 (gBRCA1/2) genotype associated with omental CRS phenotype. Methods A retrospective study of patients with newly diagnosed FIGO stage IIIC/IV HGSOC prescribed NACT and tested for gBRCA1/2 pathogenic variants (PVs) between September 2017 and December 2022 at The Christie Hospital. The Cox proportional hazards model evaluated the association between survival and key clinical factors. The chi-square test assessed the association between CRS3 (no/minimal residual tumour) and gBRCA1/2 status. Results Of 586 eligible patients, 393 underwent DPS and had a CRS reported. Independent prognostic factors by multivariable analysis were gBRCA1/2 status (PV versus wild type [WT]), CRS (3 versus 1 + 2), surgical outcome (complete versus optimal/suboptimal) and first-line poly (ADP-ribose) polymerase-1/2 inhibitor maintenance therapy (yes versus no) (all P < 0.05). There was a non-significant trend for tumours with a gBRCA2 PV having CRS3 versus WT (odds ratio [OR] = 2.13, 95% confidence intervals [CI] 0.95–4.91; P = 0.0647). By contrast, tumours with a gBRCA1 PV were significantly less likely to have CRS3 than WT (OR = 0.35, 95%CI 0.14–0.91; P = 0.0291). Conclusions Germline BRCA1/2 genotype was not clearly associated with superior omental CRS. Further research is required to understand how HGSOC biology defines CRS.

Extended panel testing in ovarian cancer reveals BRIP1 as the third most important predisposition gene

The prevalence of germline pathogenic variants (PVs) in homologous recombination repair (HRR) and Lynch syndrome (LS) genes in ovarian cancer (OC) is uncertain. An observational study reporting the detection rate of germline PVs in HRR and LS genes in all OC cases tested in the North West Genomic Laboratory Hub between September 1996 and May 2024. Effect sizes are reported using odds ratios (ORs) and 95% confidence intervals (95% CI) for unselected cases tested between April 2021 and May 2024 versus 50,703 controls from the Breast Cancer Risk after Diagnostic Gene Sequencing study. 2934 women were tested for BRCA1/2 and 433 (14.8%) had a PV. In up to 1572 women tested for PVs in non-BRCA1/2 HRR genes, detection rates were PALB2 = 0.8%, BRIP1 = 1.1%, RAD51C = 0.4% and RAD51D = 0.4%. In 940 unselected cases, BRIP1 (OR = 8.7, 95% CI 4.6-15.8) was the third most common OC predisposition gene followed by RAD51C (OR = 8.3, 95% CI 3.1-23.1), RAD51D (OR = 6.5, 95% CI 2.1-19.7), and PALB2 (OR = 3.9, 95% CI 1.5-10.3). No PVs in LS genes were detected in unselected cases. Panel testing in OC resulted in a detection rate of 2% to 3% for germline PVs in non-BRCA1/2 HRR genes, with the largest contributor being BRIP1. Screening for LS in unselected cases of OC is unnecessary.

PAZOFOS: Phase Ib and Phase II Trial of Pazopanib +/- Fosbretabulin in Advanced Recurrent Ovarian Cancer

The first part of this study is to find the recommended dosages of a combination of two drugs: pazopanib and fosbretabulin, which will be given to female patients with relapsed ovarian cancer. The second part of the study involves comparing the recommended dose of pazopanib and fosbretabulin in combination against pazopanib alone in female patients with relapsed ovarian cancer to determine whether the combination is more beneficial that pazopanib on it's own.

A Study of MEK162 vs. Physician's Choice Chemotherapy in Patients With Low-grade Serous Ovarian, Fallopian Tube or Peritoneal Cancer

The MILO Study (MEK Inhibitor in Low-grade Serous Ovarian Cancer) is a Phase 3 study during which patients with recurrent or persistent low-grade serous (LGS) carcinomas of the ovary, fallopian tube or primary peritoneum will receive either investigational study drug MEK162 or a chemotherapy chosen by the physician (liposomal doxorubicin, paclitaxel or topotecan). Patients will be followed to compare the effectiveness of the study drug to that of the selected chemotherapies. Patients may be eligible to crossover from physician's choice chemotherapy to MEK162 if they meet certain inclusion criteria including centrally confirmed disease progression. Approximately 360 patients from North America, Europe and Australia will be enrolled in this study.