Sally Lord

Informative censoring in maintenance therapy trials for advanced ovarian cancer: An empirical assessment of its impact on treatment benefit

A considerable proportion of patients in ovarian cancer maintenance trials may be censored in progression-free survival (PFS) analyses, the primary study endpoint. Such censoring is often informative, reflecting discontinuation due to toxicity, preference, or early switch to alternative therapies, potentially biasing results toward overestimating PFS benefit. We aimed to quantify the impact of informative censoring on PFS in these trials. Double-blind, placebo-controlled maintenance therapy trials were selected, and individual patient data reconstructed from published survival curves. A sensitivity analysis reclassified varying proportions of all censored events as progressions to model scenarios from 0 % to 100 % informative censoring. Hazard ratios (HRs) were re-estimated and compared with the originally reported values. Duration of therapy was compared with PFS. Twenty-two trial units (N = 8256) were included. Nineteen reported statistically significant results, falling to 14 (74 %) at the upper limit of analysis. HRs diminished progressively, with a 6 % reduction at 10 % censoring and 29 % at 100 %. In nine PARP inhibitor trials, treatment duration was shorter than PFS (mean of medians = 12.5 vs 17.6 months). Results were consistent when limited to PARP inhibitor studies. No correlation was observed between adverse events and censoring. Informative censoring can substantially distort PFS benefit estimates in ovarian cancer maintenance trials. Transparent reporting of censoring rates and their causes is essential for meaningful clinical interpretation and should be standard in all randomised maintenance therapy trials.

Poor Concordance Between Cancer Antigen-125 and RECIST Assessment for Progression in Patients With Platinum-Sensitive Relapsed Ovarian Cancer on Maintenance Therapy With a Poly(ADP-ribose) Polymerase Inhibitor

PURPOSE Cancer antigen-125 (CA-125) is recommended by treatment guidelines and widely used to diagnose ovarian cancer recurrence. The value of CA-125 as a surrogate for disease progression (PD) and its concordance with radiologic progression are unclear, particularly for women with platinum-sensitive relapsed ovarian cancer (PSROC) who have responded to chemotherapy and treated with maintenance poly(ADP-ribose) polymerase inhibitor (PARPi). METHODS In this pooled analysis of four randomized trials of maintenance PARPi or placebo (Study 19, SOLO2, ARIEL3, and NOVA), we extracted data on CA-125 PD as defined by Gynecologic Cancer InterGroup criteria and RECIST v1.1. We evaluated the concordance between CA-125 and RECIST PD and reported on the negative predictive value (NPV) and positive predictive value (PPV). RESULTS Of 1,262 participants (n = 818 PARPi, n = 444 placebo), 403 (32%) had CA-125 PD, and of these, 366 had concordant RECIST PD (PPV, 91% [95% CI, 88 to 93]). However, of 859 (68%) without CA-125 PD, 382 also did not have RECIST PD (NPV, 44% [95% CI, 41 to 48]). Within the treatment arms, PPV remained high (PARPi, 91% [95% CI, 86 to 94]; placebo, 91% [95% CI, 86 to 95]) but NPV was lower on placebo (PARPi, 53% [95% CI, 49 to 57]; placebo, 25% [95% CI, 20 to 31]). Of 477 with RECIST-only PD, most (95%) had a normal CA-125 at the start of maintenance therapy and the majority (n = 304, 64%) had CA-125 that remained within normal range. Solid organ recurrence without peritoneal disease was more common in those with RECIST-only PD than in those with CA-125 and RECIST PD (36% v 24%; P < .001). CONCLUSION In patients with PSROC treated with maintenance PARPi, almost half with RECIST PD did not have CA-125 PD, challenging current guidelines. Periodic computed tomography imaging should be considered as part of surveillance, particularly in those with a normal CA-125 at the start of maintenance therapy and on treatment.

Concordance between CA-125 and RECIST progression in patients with germline BRCA-mutated platinum-sensitive relapsed ovarian cancer treated in the SOLO2 trial with olaparib as maintenance therapy after response to chemotherapy

Limited evidence exists to support CA-125 as a valid surrogate biomarker for progression in patients with ovarian cancer on maintenance PARP inhibitor (PARPi) therapy. We aimed to assess the concordance between CA-125 and Response Evaluation Criteria in Solid Tumours (RECIST) criteria for progression in patients with BRCA mutations on maintenance PARPi or placebo. We extracted data on progression as defined by Gynecologic Cancer InterGroup CA-125, investigator- and independent central-assessed RECIST from the SOLO2/ENGOT-ov21(NCT01874353) trial. We excluded those with progression other than by RECIST, progression on date of randomisation, and no repeat CA-125 beyond baseline. We evaluated the concordance between CA-125 progression and RECIST progression, and assessed the negative (NPV) and positive predictive value (PPV). Of 295 randomised patients, 275 (184 olaparib, 91 placebo) were included. 171 patients had investigator-assessed RECIST progression. Of 80 patients with CA-125 progression, 77 had concordant RECIST progression (PPV 96%, 95% confidence interval 90-99%). Of 195 patients without CA-125 progression, 94 had RECIST progression (NPV 52%, 45-59%). Within treatment arms, PPV was similar (olaparib: 95% [84-99%], placebo: 97% [87-100%]) but NPV was lower in patients on placebo (olaparib: 60% [52-68%], placebo: 30% [20-44%]). Of 94 patients with RECIST but without CA-125 progression, 64 (68%) had CA-125 that remained within normal range. We observed similar findings using independent-assessed RECIST. Almost half the patients without CA-125 progression had RECIST progression, and most of these had CA-125 within the normal range. Regular computed tomography imaging should be considered as part of surveillance in patients treated with or without maintenance olaparib rather than relying on CA-125 alone.

Prognostic nomogram for progression-free survival in patients with BRCA mutations and platinum-sensitive recurrent ovarian cancer on maintenance olaparib therapy following response to chemotherapy

The impact of maintenance therapy with PARP inhibitors (PARPi) on progression-free survival (PFS) in patients with BRCA mutations and platinum-sensitive recurrent ovarian cancer (PSROC) varies widely. Individual prognostic factors do not reliably distinguish patients who progress early from those who have durable benefit. We developed and validated a prognostic nomogram to predict PFS in these patients. The nomogram was developed using data from a training patient cohort with BRCA mutations and high-grade serous PSROC on the placebo arm of two maintenance therapy trials, Study 19 and SOLO2/ENGOT-ov21. We performed multivariable Cox regression analysis based on pre-treatment characteristics to develop a nomogram that predicts PFS. We assessed the discrimination and validation of the nomogram in independent validation patient cohorts treated with maintenance olaparib. The nomogram includes four PFS predictors: CA-125 at randomisation, platinum-free interval, presence of measurable disease and number of prior lines of platinum therapy. In the training (placebo) cohort (internal validation C-index 0.64), median PFS in the model-predicted good, intermediate and poor-risk groups was: 7.7 (95% CI 5.3-11.3), 5.4 (4.8-5.8) and 2.9 (2.8-4.4) months, respectively. In the validation (olaparib) cohort (C-index 0.71), median PFS in the model-predicted good, intermediate and poor-risk groups was: not reached, 16.6 (13.1-22.4) and 8.3 (7.1-10.8) months, respectively. The nomogram showed good calibration in the validation cohort (calibration plot). This nomogram can be used to predict PFS and counsel patients with BRCA mutations and PSROC prior to maintenance olaparib and for stratification of patients in trials of maintenance therapies.

Reporting the trajectories of adverse events over the entire treatment course in patients with recurrent platinum-sensitive ovarian cancer treated with platinum-based combination chemotherapy regimens: A graphical approach to trial adverse event reporting

Clinical trials report adverse events (AEs) in a dense table focusing on the frequency of 'worst grade' AEs experienced over the duration of treatment. There is usually no granular information provided on the timing and trajectory of AEs or whether they are likely to worsen, improve, or remain constant over time. Non-hematologic (NH) AE data was extracted from the CALYPSO trial comparing carboplatin with pegylated liposomal doxorubicin (CD) to carboplatin with paclitaxel (CP) in recurrent ovarian cancer (ROC). Generalised estimating equations (GEE) were used to assess the risk and trajectory of combined Grade 2 or higher (G2+) AE and of each specific AE. The risk of G2+AE was also compared between treatment arms. The study included 976 patients and AE were reported for the duration of treatment. Most patients experienced at least one G2+NHAE (CP:CD, 96.0%:80.6%). Risk of combined G2+AE increased with CP (4.1% per-cycle) but decreased with CD (0.8%, P <0.01). When alopecia and sensory neuropathy were excluded, risk of G2+ AE decreased by 2.7% per-cycle, with no significant difference between treatment arms. G2+ nausea improved (15.2% per-cycle, P <0.01). G2+ sensory neuropathy worsened (29.3% per-cycle, P <0.01). Fatigue was stable (17% per-cycle, P =0.06) whilst G2+ pain decreased over time (13.4% per-cycle, P <0.01), with no difference between treatment arms. Existing trial data can be used to provide AE trajectories as illustrated here for ROC. These trajectories have utility in guiding treatment choice and potentially optimising AE management with novel therapies and treatment combinations.

Adverse events in the placebo arm of maintenance therapy trials in advanced ovarian cancer: A systematic review and meta-analysis

Maintenance treatment is standard of care for front-line (FL) and platinum-sensitive recurrent ovarian cancer (PSROC) following response to chemotherapy. Adverse events (AEs) on maintenance therapies are common and usually attributable to investigational treatments but could also be unrelated. Randomised controlled trial (RCT) with blinded placebo design is the gold standard for determining the relative differences in efficacy and AEs between treatment arms. We performed a meta-analysis to quantify AE rates in placebo arms of RCTs to determine AEs not due to investigational agents. We performed an electronic search to identify eligible RCTs in FL and PSROC settings. Data from placebo arms were extracted and pooled using the inverse variance method to determine the risk of any AE, overall and specific grade 3 or higher (G ≥ 3) AEs, and AE-related treatment delay, reduction and discontinuation. We identified 13 eligible RCTs (FL, N = 8; PSROC, N = 5) with 2224 patients who received placebo (FL, N = 1541; PSROC, N = 683). The majority experienced an AE of any grade (FL, 93.0%; PSROC, 95.2%). Substantial proportions experienced G ≥ 3 AEs (FL, 14.6%; PSROC, 18.2%). In the FL setting, AEs led to treatment delay in 14.4%, dose reduction in 4.1% and discontinuation in 2.6%. Findings were similar for PSROC: 8.4%, 5.5% and 2.1%, respectively. AEs not due to investigational agents are common in ovarian cancer patients in maintenance therapy RCTs. Potential explanations include the nocebo effect, residual toxicities from previous treatment or underlying disease. Further research is required to identify better approaches to assessing AEs in this population.

Olaparib Treatment in BRCA Mutated Ovarian Cancer Patients After Complete or Partial Response to Platinum Chemotherapy

A Phase III, randomised, double-blind, placebo-controlled, multi-centre study to assess the efficacy of olaparib maintenance monotherapy in relapsed high grade serous ovarian cancer (HGSOC) patients (including patients with primary peritoneal and / or fallopian tube cancer) or high grade endometrioid cancer with BRCA mutations (documented mutation in BRCA1 or BRCA2 that is predicted to be deleterious or suspected deleterious (known or predicted to be detrimental/lead to loss of function)) who have responded following platinum based chemotherapy.