Results of a randomised Phase II trial of olaparib, chemotherapy or olaparib and cediranib in patients with platinum-resistant ovarian cancer.

BACKGROUND: OCTOVA compared the efficacy of olaparib (O) versus weekly paclitaxel (wP) or olaparib + cediranib (O + C) in recurrent ovarian cancer (OC). AIMS: The main aim of the OCTOVA trial was to determine the progression-free survival (PFS) of olaparib (O) versus the oral combination of olaparib plus cediranib (O + C) and weekly paclitaxel (wP) in recurrent ovarian cancer (OC). METHODS: In total, 139 participants who had relapsed within 12 months of platinum therapy were randomised to O (300 mg twice daily), wP (80 mg/m2 d1,8,15, q28) or O + C (300 mg twice daily/20 mg daily, respectively). The primary endpoint was progression-free survival (PFS) of olaparib (O) versus olaparib plus cediranib (O + C) or weekly paclitaxel (wP). The sample size was calculated to observe a PFS hazard ratio (HR) 0.64 in favour of O + C compared to O (20% one-sided type I error, 80% power). RESULTS: The majority had platinum-resistant disease (90%), 22% prior PARPi, 34% prior anti-angiogenic therapy, 30% germline BRCA1/2 mutations. The PFS was increased for O + C vs O (O + C 5.4 mo (2.3, 9.6): O 3.7 mo (1.8, 7.6) HR = 0.73; 60% CI: 0.59, 0.89; P = 0.1) and no different between wP and O (wP 3.9 m (1.9, 9.1); O 3.7 mo (1.8, 7.6) HR = 0.89, 60% CI: 0.72, 1.09; P = 0.69). The main treatment-related adverse events included manageable diarrhoea (4% Grade 3) and hypertension (4% Grade 3) in the O + C arm. DISCUSSION: OCTOVA demonstrated the activity of O + C in women with recurrent disease, offering a potential non-chemotherapy option. TRIAL REGISTRATION: ISRCTN14784018, registered on 19th January 2018 http://www.isrctn.com/ISRCTN14784018 .

Antitumor Activity and Safety of Dostarlimab Monotherapy in Patients With Mismatch Repair Deficient Solid Tumors: A Nonrandomized Controlled Trial.

Importance: Mismatch repair deficiency (dMMR) occurs in various cancers, and these tumors are attractive candidates for anti-programmed cell death 1 therapies, such as dostarlimab, a recently approved immune checkpoint inhibitor. Objective: To assess the antitumor activity and safety of dostarlimab in patients with advanced or recurrent dMMR solid tumors. Design, Setting, And Participants: The GARNET trial was a phase 1, open-label, single-group, multicenter study that began enrolling May 8, 2017. Participants had advanced or recurrent dMMR and microsatellite instability-high (MSI-H) or polymerase epsilon (POLE)-altered solid tumors. The data cut for this interim analysis was from November 1, 2021, with median follow-up of 27.7 months. Interventions: Patients received 500 mg of dostarlimab intravenously every 3 weeks for 4 doses, then 1000 mg every 6 weeks until disease progression, discontinuation, or withdrawal. Main Outcomes and Measures: The primary objective was to evaluate objective response rate and duration of response in patients with dMMR solid tumors by blinded independent central review using Response Evaluation Criteria in Solid Tumors, version 1.1. Results: The efficacy population included 327 patients (median [range] age, 63 [24-85] years; 235 [71.9%] female; 7 [2.1%] Asian, 6 [1.8%] Black, and 206 [63.0%] White patients), with 141 patients (43.1%) with dMMR endometrial cancer, 105 patients (32.1%) with dMMR colorectal cancer, and 81 patients (24.8%) with other dMMR tumor types. All patients had at least 1 previous line of therapy. Objective response rate assessed per blinded independent central review for dMMR solid tumors was 44.0% (95% CI, 38.6% to 49.6%). Median duration of response was not reached (range, ≥1.18 to ≥47.21 months); 72.2% of responders (104 of 144) had a response lasting 12 or more months. Median progression-free survival was 6.9 months (95% CI, 4.2 to 13.6 months); probability of progression-free survival at 24 months was 40.6% (95% CI, 35.0% to 46.1%). Median overall survival was not reached (95% CI, 31.6 months to not reached). The most frequent immune-related adverse events were hypothyroidism (25 [6.9%]), alanine aminotransferase increase (21 [5.8%]), and arthralgia (17 [4.7%]). No new safety concerns were identified. Conclusions And Relevance: In this nonrandomized controlled trial, dostarlimab was a well-tolerated treatment option with rapid, robust, and durable antitumor activity in patients with diverse dMMR solid tumors. These findings suggest that dostarlimab provides meaningful long-term benefit in a population with high unmet need. Trial Registration: ClinicalTrials.gov Identifier: NCT02715284.

Lurbinectedin in patients with pretreated endometrial cancer: results from a phase 2 basket clinical trial and exploratory translational study.

Second-line treatment of endometrial cancer is an unmet medical need. Lurbinectedin showed promising antitumor activity in a phase I study in combination with doxorubicin in advanced endometrial cancer. This phase 2 Basket trial evaluated lurbinectedin 3.2 mg/m2 1-h intravenous infusion every 3 weeks in a cohort of 73 patients with pretreated endometrial cancer. The primary endpoint was overall response rate (ORR) according to RECIST v1.1. Secondary endpoints included duration of response (DoR), progression-free survival (PFS), overall survival (OS), safety and an exploratory translational study. Confirmed complete (CR) and partial response (PR) was reported in two and six patients, respectively (ORR = 11.3%; 95%CI, 5.0-21.0%). Median DoR was 9.2 months (95%CI, 3.4-18.0 months), median PFS was 2.6 months (95%CI, 1.4-4.0 months) and median OS was 9.3 months (95%CI, 6.1-12.8 months). Molecular subtypes showed differences in PFS rate at 6 months (p53abn 23.7% vs. "No Specific Molecular Profile" [NSMP] 42.9%) and median OS (p53abn 6.6 months vs. NSMP 16.1 months). The most common treatment-related adverse events (mostly grade 1/2) were fatigue (54.8% of patients), nausea (50.7%), vomiting (26.0%) decreased appetite (17.8%). and constipation, (19.2%). The most common grade 3/4 toxicity was neutropenia (43.8%; grade 4, 19.2%; febrile neutropenia, 4.1%). In conclusion, considering the exploratory aim of this trial and the hints of antitumor activity observed together with a predictable and manageable safety profile, further biomarker-based development of lurbinectedin is recommended in this indication in combination with other agents. Clinicaltrials.gov identifier: NCT02454972.

Safety and anti-tumour activity of the IgE antibody MOv18 in patients with advanced solid tumours expressing folate receptor-alpha: a phase I trial.

All antibodies approved for cancer therapy are monoclonal IgGs but the biology of IgE, supported by comparative preclinical data, offers the potential for enhanced effector cell potency. Here we report a Phase I dose escalation trial (NCT02546921) with the primary objective of exploring the safety and tolerability of MOv18 IgE, a chimeric first-in-class IgE antibody, in patients with tumours expressing the relevant antigen, folate receptor-alpha. The trial incorporated skin prick and basophil activation tests (BAT) to select patients at lowest risk of allergic toxicity. Secondary objectives were exploration of anti-tumour activity, recommended Phase II dose, and pharmacokinetics. Dose escalation ranged from 70 µg-12 mg. The most common toxicity of MOv18 IgE is transient urticaria. A single patient experienced anaphylaxis, likely explained by detection of circulating basophils at baseline that could be activated by MOv18 IgE. The BAT assay was used to avoid enrolling further patients with reactive basophils. The safety profile is tolerable and maximum tolerated dose has not been reached, with evidence of anti-tumour activity observed in a patient with ovarian cancer. These results demonstrate the potential of IgE therapy for cancer.

Safety, Efficacy, and Biomarker Analyses of Dostarlimab in Patients with Endometrial Cancer: Interim Results of the Phase I GARNET Study.

PURPOSE: This interim report of the GARNET phase I trial presents efficacy and safety of dostarlimab in patients with advanced or recurrent endometrial cancer (EC), with an analysis of tumor biomarkers as prognostic indicators. PATIENTS AND METHODS: A total of 153 patients with mismatch repair deficient (dMMR)/microsatellite instability-high (MSI-H) and 161 patients with mismatch repair proficient (MMRp)/microsatellite stable (MSS) EC were enrolled and dosed. Patients received 500 mg dostarlimab every 3 weeks for four cycles, then 1,000 mg every 6 weeks until progression. Primary endpoints were objective response rate (ORR) and duration of response (DOR). RESULTS: A total of 143 patients with dMMR/MSI-H EC and 156 patients with MMRp/MSS EC were evaluated for efficacy. ORR was 45.5% (n = 65) and 15.4% (n = 24) for dMMR/MSI-H EC and MMRp/MSS EC, respectively. Median DOR for dMMR/MSI-H EC was not met (median follow-up, 27.6 months); median DOR for MMRp/MSS EC was 19.4 months. The ORRs by combined positive score (CPS) ≥1 status were 54.9% and 21.7% for dMMR/MSI-H EC and MMRp/MSS EC, respectively. ORRs by high tumor mutational burden (≥10 mutations/Mb) were 47.8% (43/90) and 45.5% (5/11) for dMMR/MSI-H EC and MMRp/MSS EC, respectively. ORR in TP53mut or POLεmut molecular subgroups was 18.1% (17/94) and 40.0% (2/5), respectively. The safety profile of dostarlimab was consistent with previous reports. CONCLUSIONS: Dostarlimab demonstrated durable antitumor activity and safety in patients with dMMR/MSI-H EC. Biomarkers associated with EC may identify patients likely to respond to dostarlimab. See related commentary by Jangra and Dhani, p. 4521.

A plain language summary of results from the GARNET study of dostarlimab in patients with endometrial cancer.

WHAT IS THIS SUMMARY ABOUT?: Dostarlimab, also known by the brand name JEMPERLI, is a medicine that can be used to treat certain types of endometrial cancer. GARNET is an ongoing phase 1 clinical study that is testing the safety and side effects of dostarlimab and the best way to administer it to patients. The results presented in this summary are from a time point in the middle of the study. WHAT WERE THE RESULTS?: The results from the GARNET study published in 2022 showed how well dostarlimab worked for people participating in the study. Dostarlimab was found to reduce the size of tumors in patients with certain types of endometrial cancer. The patients treated with dostarlimab had side effects that could be managed and few severe side effects. WHAT DO THE RESULTS MEAN?: The results of the GARNET study led to dostarlimab being approved to treat patients with certain types of endometrial cancer. For patients with advanced-stage endometrial cancer, or endometrial cancer that has come back after chemotherapy (recurrent), there are few treatment options. The results suggest that dostarlimab may provide long-term benefits for these patients.

Assessing the quality of patient-reported outcome measurements for gynecological cancers: a systematic review.

Aim: To provide perspective on patient-reported outcome measurement (PROM) instruments to adopt in patients diagnosed with gynecological cancers. Methods: A systematic search was conducted to identify PROMs developed for or applied in gynecological cancer populations. PROMs identified in more than one study subsequently underwent assessment according to the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) criteria. Results: Overall, 55 PROMs were identified within the gynecological cancer setting, and 20 were assessed according to COSMIN guidelines. Most PROMs had limited information reported, but a best fit approach was adopted to recommend a number of instruments for use in patients with gynecological cancer. Conclusion: Further study to assess the methodological quality of each PROM utilized in gynecological cancers is warranted to endorse the recommendations of this review.

Gynecological cancers are cancers which occur in the reproductive system of women. The cervical cancer screening program and development of new treatments mean that women with gynecological cancers are now living longer than before. However, these new treatments may have side effects that can affect the quality of life of women with cancer. Many care providers now agree that looking at women's quality of life during their gynecological cancer journey is an important part of their treatment. Patient-reported outcome measurements (PROMs) are questionnaires that the patient completes to measure their symptoms and quality of life. There are a lot of PROMs available to choose from, and it can be difficult to select one that is relevant and understandable for all women with gynecological cancer. This article searched the literature to find all PROMs that can be completed by women with gynecological cancer and then measured each of the PROM's quality. PROM quality was measured by looking at validity (whether the questionnaire measures what it is supposed to measure), reliability (that the questionnaire is not subject to different errors in measuring), and sensitivity (that the questionnaire can measure changes in questionnaire scores over time). Overall, this study found that there were a few PROMs that were of good enough quality to be completed by women with gynecological cancers. These questionnaires are called the European Organisation for Research and Treatment of Cancer Quality-of-Life Questionnaire Cervical Cancer Module (EORTC QLQ-CX24), the Functional Assessment of Cancer Therapy - General (FACT-G), European Organisation for Research and Treatment of Cancer Quality-of-Life Questionnaire Endometrial Cancer (EORTC QLQ-EN24), Functional Assessment of Cancer Therapy Gynecologic Oncology Group ­ Neurotoxicity (FACT-GOG/Ntx), Functional Assessment of Cancer Therapy ­ Ovarian (FACT-O) and Female Sexual Function Index (FSFI). Each questionnaire can be filled out by women with different types of gynecological cancer, and the FSFI measures sexual problems that women may experience after cancer treatment.

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

OBJECTIVE: 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. METHODS: 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 BRCA1/2 mutation and/or a Genomic Instability Score (GIS) ≥42. Testing was coordinated by the NHS Genomic Laboratory Hub network. RESULTS: The myChoice assay was performed on 2829 tumors. Of these, 2474 (87%) and 2178 (77%) successfully underwent BRCA1/2 and GIS testing, respectively. All complete and partial assay failures occurred due to low tumor cellularity and/or low tumor DNA yield. 385 tumors (16%) contained a BRCA1/2 mutation and 814 (37%) had a GIS ≥42. Tumors with a GIS ≥42 were more likely to be BRCA1/2 wild-type (n=510) than BRCA1/2 mutant (n=304). The distribution of GIS was bimodal, with BRCA1/2 mutant tumors having a higher mean score than BRCA1/2 wild-type tumors (61 vs 33, respectively, χ2 test p<0.0001). CONCLUSION: 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.

Phase I/II sequencing study of azacitidine, epacadostat, and pembrolizumab in advanced solid tumors.

BACKGROUND: Indoleamine 2,3-dioxygenase 1 (IDO1), an interferon-inducible enzyme, contributes to tumor immune intolerance. Immune checkpoint inhibition may increase interferon levels; combining IDO1 inhibition with immune checkpoint blockade represents an attractive strategy. Epigenetic agents trigger interferon responses and may serve as an immunotherapy priming method. We evaluated whether epigenetic therapy plus IDO1 inhibition and immune checkpoint blockade confers clinical benefit to patients with advanced solid tumors. METHODS: ECHO-206 was a Phase I/II study where treatment-experienced patients with advanced solid tumors (N = 70) received azacitidine plus an immunotherapy doublet (epacadostat [IDO1 inhibitor] and pembrolizumab). Sequencing of treatment was also assessed. Primary endpoints were safety/tolerability (Phase I), maximum tolerated dose (MTD) or pharmacologically active dose (PAD; Phase I), and investigator-assessed objective response rate (ORR; Phase II). RESULTS: In Phase I, no dose-limiting toxicities were reported, the MTD was not reached; a PAD was not determined. ORR was 5.7%, with four partial responses. The most common treatment-related adverse events (AEs) were fatigue (42.9%) and nausea (42.9%). Twelve (17.1%) patients experienced ≥1 fatal AE, one of which (asthenia) was treatment-related. CONCLUSIONS: Although the azacitidine-epacadostat-pembrolizumab regimen was well tolerated, it was not associated with substantial clinical response in patients with advanced solid tumors previously exposed to immunotherapy.

A Phase 1/2 trial of SRA737 (a Chk1 inhibitor) administered orally in patients with advanced cancer.

BACKGROUND: This was a first-in-human Phase 1/2 open-label dose-escalation study of the novel checkpoint kinase 1 (Chk1) inhibitor SRA737. METHODS: Patients with advanced solid tumours enrolled in dose-escalation cohorts and received SRA737 monotherapy orally on a continuous daily (QD) dosing schedule in 28-day cycles. Expansion cohorts included up to 20 patients with prospectively selected, pre-specified response predictive biomarkers. RESULTS: In total, 107 patients were treated at dose levels from 20-1300 mg. The maximum tolerated dose (MTD) of SRA737 was 1000 mg QD, the recommended Phase 2 dose (RP2D) was 800 mg QD. Common toxicities of diarrhoea, nausea and vomiting were generally mild to moderate. Dose-limiting toxicity at daily doses of 1000 and 1300 mg QD SRA737 included gastrointestinal events, neutropenia and thrombocytopenia. Pharmacokinetic analysis at the 800 mg QD dose showed a mean Cmin of 312 ng/mL (546 nM), exceeding levels required to cause growth delay in xenograft models. No partial or complete responses were seen. CONCLUSIONS: SRA737 was well tolerated at doses that achieved preclinically relevant drug concentrations but single agent activity did not warrant further development as monotherapy. Given its mechanism of action resulting in abrogating DNA damage repair, further clinical development of SRA737 should be as combination therapy. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov NCT02797964.

BRCA1 secondary splice-site mutations drive exon-skipping and PARP inhibitor resistance.

BRCA1 splice isoforms Δ11 and Δ11q can contribute to PARP inhibitor (PARPi) resistance by splicing-out the mutation-containing exon, producing truncated, partially-functional proteins. However, the clinical impact and underlying drivers of BRCA1 exon skipping remain undetermined. We analyzed nine ovarian and breast cancer patient derived xenografts (PDX) with BRCA1 exon 11 frameshift mutations for exon skipping and therapy response, including a matched PDX pair derived from a patient pre- and post-chemotherapy/PARPi. BRCA1 exon 11 skipping was elevated in PARPi resistant PDX tumors. Two independent PDX models acquired secondary BRCA1 splice site mutations (SSMs), predicted in silico to drive exon skipping. Predictions were confirmed using qRT-PCR, RNA sequencing, western blots and BRCA1 minigene modelling. SSMs were also enriched in post-PARPi ovarian cancer patient cohorts from the ARIEL2 and ARIEL4 clinical trials. We demonstrate that SSMs drive BRCA1 exon 11 skipping and PARPi resistance, and should be clinically monitored, along with frame-restoring secondary mutations.

Efficacy and Safety of Weekly Paclitaxel Plus Vistusertib vs Paclitaxel Alone in Patients With Platinum-Resistant Ovarian High-Grade Serous Carcinoma: The OCTOPUS Multicenter, Phase 2, Randomized Clinical Trial.

Importance: Patients with platinum-resistant or refractory ovarian high-grade serous carcinoma (PR-HGSC) have a poor prognosis and few therapeutic options. Preclinical studies support targeting PI3K/AKT/mTOR signaling in this setting, and a phase 1 study of the dual mTORC1/mTORC2 inhibitor vistusertib with weekly paclitaxel showed activity. Objective: To evaluate whether the addition of vistusertib to weekly paclitaxel improves clinical outcomes in patients with PR-HGSC. Design, Setting, and Participants: This phase 2, double-blind, placebo-controlled multicenter randomized clinical trial recruited patients from UK cancer centers between January 2016 and March 2018. Patients with PR-HGSC of ovarian, fallopian tube, or primary peritoneal origin and with measurable or evaluable disease (Response Evaluation Criteria in Solid Tumors version 1.1 and/or Gynecological Cancer Intergroup cancer antigen 125 criteria) were eligible. There were no restrictions on number of lines of prior therapy. Data analysis was performed from May 2019 to January 2022. Interventions: Patients were randomized (1:1) to weekly paclitaxel (80 mg/m2 days 1, 8, and 15 of a 28-day cycle) plus oral vistusertib (50 mg twice daily) or placebo. Main Outcomes and Measures: The primary end point was progression-free survival in the intention-to-treat population. Secondary end points included response rate, overall survival, and quality of life. Results: A total of 140 patients (median [range] age, 63 [36-86] years; 17.9% with platinum-refractory disease; 53.6% with ≥3 prior therapies) were randomized. In the paclitaxel plus vistusertib vs paclitaxel plus placebo groups, there was no difference in progression-free survival (median, 4.5 vs 4.1 months; hazard ratio [HR], 0.84; 80% CI, 0.67-1.07; 1-sided P = .18), overall survival (median, 9.7 vs 11.1 months; HR, 1.21; 80% CI, 0.91-1.60) or response rate (odds ratio, 0.86; 80% CI, 0.55-1.36). Grade 3 to 4 adverse events were 41.2% (weekly paclitaxel plus vistusertib) vs 36.7% (weekly paclitaxel plus placebo), and there was no difference in quality of life. Conclusions and Relevance: In this randomized clinical trial of weekly paclitaxel and dual mTORC1/2 inhibition in patients with PR-HGSC, vistusertib did not improve clinical activity of weekly paclitaxel. Trial Registration: isrctn.org Identifier: ISRCTN16426935.

Mathematical modeling of the early modeled CA-125 longitudinal kinetics (KELIM-PARP) as a pragmatic indicator of rucaparib efficacy in patients with recurrent ovarian carcinoma in ARIEL2 & STUDY 10.

BACKGROUND: PARP inhibitors (PARPi) have revolutionized the management of advanced ovarian carcinoma, and were investigated as forefront treatment in recurrent disease. The objective was to explore if mathematical modeling of the early longitudinal CA-125 kinetics could be used as a pragmatic indicator of the subsequent rucaparib efficacy, like it is for platinum-based chemotherapy. METHODS: The datasets of ARIEL2 and Study 10 involving recurrent HGOC patients treated with rucaparib were retrospectively investigated. The same strategy as those successfully developed for platinum chemotherapy, based on CA-125 ELIMination rate constant K (KELIM™), was implemented. Individual values of rucaparib-adjusted KELIM (KELIM-PARP) were estimated based on the longitudinal CA-125 kinetics during the first 100 treatment days, and then scored as favorable (KELIM-PARP ≥1.0) or unfavorable (KELIM-PARP <1.0). The prognostic value of KELIM-PARP regarding treatment efficacy (radiological response, and progression-free survival (PFS)) was assessed using univariable/multivariable analyses, with respect to platinum-sensitivity and homologous recombination deficiency (HRD) status. FINDINGS: The data from 476 patients were assessed. The CA-125 longitudinal kinetics during the first 100-treatment days could be accurately assessed using the KELIM-PARP model. In patients with platinum-sensitive diseases, BRCA mutational status KELIM-PARP score and were associated with subsequent complete/partial radiological responses (KELIM-PARP: odds-ratio = 2.81, 95% CI 1.86-4.52), and PFS (KELIM-PARP: hazard-ratio = 0.67, 95% CI 0.50-0.91). The patients with BRCA-wild type cancer and favorable KELIM-PARP experienced long PFS with rucaparib regardless of HRD. In platinum-resistant disease patients, KELIM-PARP was associated with subsequent radiological response (odds-ratio = 2.80, 95% CI 1.82-4.72). INTERPRETATION: This proof-of-concept study confirms the early CA-125 longitudinal kinetics during rucaparib in recurrent HGOC patients are assessable by mathematical modeling, to generate individual a KELIM-PARP score associated with the subsequent efficacy. This pragmatic strategy might be useful for selecting the patients for PARPi-based combination regimens, when identifying efficacy biomarker is challenging. Further assessment of this hypothesis is warranted. FUNDING: The present study was supported by Clovis Oncology with a grant to academic research association.

Folate receptor alpha in ovarian cancer tissue and patient serum is associated with disease burden and treatment outcomes.

BACKGROUND: Survival rates for ovarian cancer remain poor, and monitoring and prediction of therapeutic response may benefit from additional markers. Ovarian cancers frequently overexpress Folate Receptor alpha (FRα) and the soluble receptor (sFRα) is measurable in blood. Here we investigated sFRα as a potential biomarker. METHODS: We evaluated sFRα longitudinally, before and during neo-adjuvant, adjuvant and palliative therapies, and tumour FRα expression status by immunohistrochemistry. The impact of free FRα on the efficacy of anti-FRα treatments was evaluated by an antibody-dependent cellular cytotoxicity assay. RESULTS: Membrane and/or cytoplasmic FRα staining were observed in 52.7% tumours from 316 ovarian cancer patients with diverse histotypes. Circulating sFRα levels were significantly higher in patients, compared to healthy volunteers, specifically in patients sampled prior to neoadjuvant and palliative treatments. sFRα was associated with FRα cell membrane expression in the tumour. sFRα levels decreased alongside concurrent tumour burden in patients receiving standard therapies. High concentrations of sFRα partly reduced anti-FRα antibody tumour cell killing, an effect overcome by increased antibody doses. CONCLUSIONS: sFRα may present a non-invasive marker for tumour FRα expression, with the potential for monitoring patient response to treatment. Larger, prospective studies should evaluate FRα for assessing disease burden and response to systemic treatments.

A Phase I/II Trial of Oral SRA737 (a Chk1 Inhibitor) Given in Combination with Low-Dose Gemcitabine in Patients with Advanced Cancer.

PURPOSE: This was a Phase I/II trial of the novel checkpoint kinase 1 (Chk1) inhibitor SRA737 given in combination with gemcitabine. Its objectives were to establish the safety profile, recommended Phase 2 dose (RP2D), pharmacokinetics profile, and clinical activity of SRA737. PATIENTS AND METHODS: Patients with advanced solid tumors were enrolled into dose-escalation cohorts and treated in 28-day cycles with oral SRA737 on days 2, 3, 9, 10, 16, and 17, and intravenous gemcitabine on days 1, 8, and 15. Treatment was continued until progression. Each expansion cohort included up to 20 patients with specific genetically defined tumors. RESULTS: The RP2D was determined to be 500 mg SRA737 combined with low-dose (250 mg/m2) gemcitabine. Of 143 enrolled patients, 77 were treated at doses of at least 500 mg SRA737 combined with 250 mg/m2 gemcitabine. Common toxicities of nausea, vomiting, fatigue, and diarrhea were primarily mild to moderate, and rarely led to treatment discontinuation. Anemia, neutropenia, and thrombocytopenia were grade ≥3 in 11.7%, 16.7%, and 10% of patients treated at the RP2D, respectively. The objective response rate (ORR) was 10.8% overall and notably the ORR in anogenital cancer was 25%. Partial tumor responses were observed in anogenital cancer, cervical cancer, high-grade serous ovarian cancer, rectal cancer, and small cell lung cancer. CONCLUSIONS: SRA737 in combination with low-dose gemcitabine was well tolerated with lower myelotoxicity than has been seen at standard doses of gemcitabine or with other combinations of Chk1 inhibitors with gemcitabine. Tumor responses were observed in anogenital and other solid tumors.

A Phase 1B open-label study of gedatolisib (PF-05212384) in combination with other anti-tumour agents for patients with advanced solid tumours and triple-negative breast cancer.

BACKGROUND: This Phase 1b study (B2151002) evaluated the PI3K/mTOR inhibitor gedatolisib (PF-05212384) in combination with other anti-tumour agents in advanced solid tumours. METHODS: Patients with various malignancies were administered gedatolisib (90‒310 mg intravenously every week [QW]) plus docetaxel (arm A) or cisplatin (arm B) (each 75 mg/m2 intravenously Q3W) or dacomitinib (30 or 45 mg/day orally). The safety and tolerability of combination therapies were assessed during dose escalation; objective response (OR) and safety were assessed during dose expansion. RESULTS: Of 110 patients enrolled, 107 received gedatolisib combination treatment. Seven of 70 (10.0%) evaluable patients had dose-limiting toxicities; the most common was grade 3 oral mucositis (n = 3). Based upon reprioritisation of the sponsor's portfolio, dose expansion focused on arm B, gedatolisib (180 mg QW) plus cisplatin in patients (N = 22) with triple-negative breast cancer (TNBC). OR (95% CI) was achieved in four of ten patients in first-line (overall response rate 40.0% [12.2-73.8%]) and four of 12 in second/third-line (33.3% [9.9-65.1%]) settings. One patient in each TNBC arm (10%, first-line; 8.3%, second/third-line) achieved a complete response. CONCLUSIONS: Gedatolisib combination therapy showed an acceptable tolerability profile, with clinical activity at the recommended Phase 2 dose in patients with TNBC. CLINICAL TRIAL: ClinicalTrial.gov: NCT01920061.

Efficacy and safety of rucaparib treatment in patients with BRCA-mutated, relapsed ovarian cancer: final results from Study 10.

BACKGROUND: Study 10, a four-part Phase 1/2 study, evaluated oral rucaparib monotherapy in patients with advanced solid tumours. Here we report the final efficacy and safety results in heavily pretreated patients with ovarian cancer who received rucaparib in Study 10 Parts 2A and 2B. METHODS: Parts 2A and 2B (Phase 2 portions) enrolled patients with relapsed, high-grade, platinum-sensitive or platinum-resistant, BRCA-mutated ovarian cancer who had received 2-4 (Part 2A) or 3-4 (Part 2B) prior chemotherapies. Patients received oral rucaparib 600 mg twice daily (starting dose). The primary endpoint was the investigator-assessed objective response rate (ORR) by RECIST v1.1. RESULTS: Fifty-four patients were enrolled: 42 in Part 2A (all had platinum-sensitive disease) and 12 in Part 2B (4 with platinum-sensitive disease; 8 with platinum-resistant disease). ORR was 59.3% (95% CI 45.0-72.4%). The median time to onset of the most common nonhaematological treatment-emergent adverse events (TEAEs) was typically early (<56 days) and was later for haematological TEAEs (53-84 days). The median duration of grade ≥3 TEAEs was ≤13 days. CONCLUSIONS: In patients with relapsed, platinum-sensitive or platinum-resistant germline BRCA-mutant high-grade ovarian cancer who had received ≥2 prior chemotherapies, rucaparib had robust antitumour activity with a safety profile consistent with prior reports. CLINICAL TRIAL REGISTRATION: NCT01482715.

First-in-human phase I/II, open-label study of the anti-OX40 agonist INCAGN01949 in patients with advanced solid tumors.

BACKGROUND: OX40 is a costimulatory receptor upregulated on antigen-activated T cells and constitutively expressed on regulatory T cells (Tregs). INCAGN01949, a fully human immunoglobulin G1κ anti-OX40 agonist monoclonal antibody, was designed to promote tumor-specific immunity by effector T-cell activation and Fcγ receptor-mediated Treg depletion. This first-in-human study was conducted to determine the safety, tolerability, and preliminary efficacy of INCAGN01949. METHODS: Phase I/II, open-label, non-randomized, dose-escalation and dose-expansion study conducted in patients with advanced or metastatic solid tumors. Patients received INCAGN01949 monotherapy (7-1400 mg) in 14-day cycles while deriving benefit. Safety measures, clinical activity, pharmacokinetics, and pharmacodynamic effects were assessed and summarized with descriptive statistics. RESULTS: Eighty-seven patients were enrolled; most common tumor types were colorectal (17.2%), ovarian (8.0%), and non-small cell lung (6.9%) cancers. Patients received a median three (range 1-9) prior therapies, including immunotherapy in 24 patients (27.6%). Maximum tolerated dose was not reached; one patient (1.1%) receiving 350 mg dose reported dose-limiting toxicity of grade 3 colitis. Treatment-related adverse events were reported in 45 patients (51.7%), with fatigue (16 (18.4%)), rash (6 (6.9%)), and diarrhea (6 (6.9%)) being most frequent. One patient (1.1%) with metastatic gallbladder cancer achieved a partial response (duration of 6.3 months), and 23 patients (26.4%) achieved stable disease (lasting >6 months in one patient). OX40 receptor occupancy was maintained over 90% among all patients receiving doses of ≥200 mg, while no treatment-emergent antidrug antibodies were detected across all dose levels. Pharmacodynamic results demonstrated that treatment with INCAGN01949 did not enhance proliferation or activation of T cells in peripheral blood or reduce circulating Tregs, and analyses of tumor biopsies did not demonstrate any consistent increase in effector T-cell infiltration or function, or decrease in infiltrating Tregs. CONCLUSION: No safety concerns were observed with INCAGN01949 monotherapy in patients with metastatic or advanced solid tumors. However, tumor responses and pharmacodynamic effects on T cells in peripheral blood and post-therapy tumor biopsies were limited. Studies evaluating INCAGN01949 in combination with other therapies are needed to further evaluate the potential of OX40 agonism as a therapeutic approach in patients with advanced solid tumors. TRIAL REGISTRATION NUMBER: NCT02923349.