Prospective evaluation of the tolerability and efficacy of niraparib dosing based on baseline body weight and platelet count: Results from the PRIMA/ENGOT-OV26/GOG-3012 trial

BACKGROUND

The PRIMA/ENGOT-OV26/GOG-3012 (NCT02655016) trial was amended to prospectively evaluate the safety and efficacy of an individualized starting dose (ISD) regimen of niraparib for first-line maintenance therapy in patients with newly diagnosed advanced ovarian cancer.

METHODS

In the phase 3 PRIMA trial, patients with newly diagnosed advanced ovarian cancer with a complete/partial response to first-line platinum-based chemotherapy (N = 733) were initially treated with a fixed starting dose (FSD) regimen of 300 mg every day. Subsequently, the protocol was amended so newly enrolled patients received an ISD: 200 mg every day in patients with baseline body weight < 77 kg or baseline platelet count < 150,000/µL, and 300 mg every day in all other patients. Efficacy and safety outcomes were assessed by starting dose.

RESULTS

Overall, 475 (64.8%) patients were assigned to an FSD (niraparib, n = 317; placebo, n = 158) and 258 (35.2%) were assigned to an ISD (niraparib, n = 170; placebo, n = 88). Efficacy in patients who received FSD or ISD was similar for the overall (FSD hazard ratio [HR], 0.59 [95% CI, 0.46-0.76] vs. ISD HR, 0.69 [95% CI, 0.48-0.98]) and the homologous recombination-deficient (FSD HR, 0.44 [95% CI, 0.30-0.64] vs. ISD HR, 0.39 [95% CI, 0.22-0.72]) populations. In patients with low body weight/platelet count, rates of grades ≥3 and 4 hematologic treatment-emergent adverse events, dose interruptions, and dose reductions were lower for those who received ISD than for those who received FSD.

CONCLUSIONS

In PRIMA, similar dose intensity, similar efficacy, and improved safety were observed with the ISD compared with the FSD regimen.

Glassy cell carcinoma of the cervix: Findings from a combined National Cancer Database analysis and single institution review of treatment patterns and outcomes

OBJECTIVES

To describe stage, treatment patterns, and survival for glassy cell carcinoma of the cervix (GCCC), a poorly understood rare tumor.

METHODS

Clinical data and survival were compared between GCCC and more common histologic types using the National Cancer Database (NCDB) from 2004 to 2017. A retrospective review of GCCC cases at our institution from 2012 to 2020 was simultaneously performed with staging updated according to 2018 FIGO staging. Descriptive statistics and survival analyses were performed, and outcomes compared to historical references.

RESULTS

143/89,001 (0.16%) NCDB cervical cancer cases were GCCC. Compared to other histologies, GCCC cases were younger, with 74.8% diagnosed before age 50. Stage distribution was similar. Stage I cases were less commonly treated with surgery alone (19/69, 27%). 79.4% of locally advanced (stage II-IVA) cases were treated with definitive chemoradiation. GCCC demonstrated worse OS for early-stage and locally-advanced disease. No survival differences were observed for patients with stage IVB disease. Our institutional review identified 14 GCCC cases. Median age at diagnosis was 34 years. All nine early-stage cases underwent radical hysterectomy. Adjuvant radiation was given for cases meeting Sedlis criteria (4/9, 44%). All five advanced stage cases were stage IIIC and received definitive chemoradiation. Recurrence rate was 0% (0/9) for early-stage and 60% (3/5) for advanced-stage cases. 3-year PFS was 100% for early-stage and 40% for advanced-stage. 3-year OS was 100% for early-stage and 60% for advanced-stage GCCC.

CONCLUSIONS

GCCC presents at earlier ages than other cervical cancer histologic types. Although NCDB showed worse OS, our more contemporary institutional review, which incorporates updated staging and newer treatment modalities found outcomes more similar to historical references of more common histologic subtypes.

Combination lenvatinib plus pembrolizumab in the treatment of ovarian clear cell carcinoma: A case series

Effective second-line treatment options for patients with recurrent ovarian clear cell carcinoma (OCCC) are limited. This case series sought to report tumor characteristics and oncologic outcomes in a small group of patients treated with combination lenvatinib and pembrolizumab. A retrospective analysis of patients with ovarian clear cell carcinoma treated with combination lenvatinib and pembrolizumab at a single institution was performed. Patient and tumor characteristics were collected including demographics and germline/somatic testing. Clinical outcomes were also evaluated and reported. Three patients with recurrent OCCC were included in the study. The median age of patients was 48 years old. All patients had platinum-resistant disease and had received 1-3 prior lines of therapy. The overall response rate was 100% (3/3). Progression-free survival ranged from 10 months to not-yet-reached. One patient remains on treatment, while the other two died of disease with overall survival of 14 and 27 months. Combination lenvatinib-pembrolizumab demonstrated favorable clinical response in these patients with platinum-resistant, recurrent, ovarian clear cell carcinoma.

Use of the Khorana score to predict venous thromboembolism in patients undergoing chemotherapy for uterine cancer

Objective

Gynecologic cancers are associated with a high risk of venous thromboembolism (VTE). The Khorana score is a validated tool to assess risk of VTE in cancer patients. The purpose of this study is to determine if the Khorana score can be used as a risk stratification tool for VTE in patients with uterine cancer undergoing chemotherapy.

Methods

A retrospective cohort study of patients with newly diagnosed uterine cancer receiving chemotherapy over a 4-year period was conducted. The patients were stratified based on their Khorana score as well as their chemotherapy sequence, neoadjuvant or definitive versus adjuvant.

Results

A total of 276 patients were included: 40 received neoadjuvant or definitive, 236 adjuvant chemotherapy. Most patients had advanced stage disease (64.5%). 18 (6.5%) patients developed VTE within 180 days of initiating chemotherapy. High Khorana score was associated with a non-significant increase in VTE (K ≥ 2 OR 1.17, CI 0.40-3.39, K ≥ 3 OR 1.69, CI 0.61-4.69) but had poor predictive accuracy based on area under the curve (K ≥ 2 0.51, K ≥ 3 0.55). The VTE rate was higher in the neoadjuvant/definitive chemotherapy group to adjuvant (12.5% vs 5.5%, p = 0.11). While the former group had a higher average Khorana score (2.35 vs 1.93, p = 0.0048), this was not predictive of VTE.

Conclusions

While validated in other cancer types, the Khorana score was found to be a poor predictor of VTE in patients with uterine cancer. The use of the Khorana score to guide routine thromboprophylaxis in these patients should be used with caution and further investigation is warranted.

Recurrence rate in early-stage epithelial ovarian cancer: Is there a role for upfront maintenance with PARP inhibitors in stages I and II?

Objective

To determine the recurrence rate and survival among early-stage epithelial ovarian cancer cases considering homologous recombination deficiency (HRD) status.

Methods

Single institution retrospective study of stage I/II EOC patients from 2017 to 2020. HRD was defined as evidence of germline or somatic BRCA mutation, or loss of heterozygosity (LOH)/genomic instability (GIS) as determined by companion diagnostic tests. Kaplan-Meier analyses were performed.

Results

89 stage I/II cases were included. 4/89 (4.5%) had a germline BRCA1/2 mutation, 8 (9%) were germline negative but had a somatic BRCA mutation, and 8 (9%) were BRCA wild-type but had evidence of LOH/GIS on somatic testing; these 20/89 (22%) cases comprised the HRD group. The remaining tumors were confirmed homologous recombination proficient (HRP, 35/89, 39%) or homologous recombination unknown (HRU, 34/89, 38%). The overall recurrence rate was 33/89 (37%). There were more recurrences among HRD cases (14/20, 70%) compared to HRP/HRU cases (19/69, 27.5%, p = 0.0012). Median Recurrence-Free Survival (RFS) was 35 months for HRD cases and 225 months for HRP/HRU cases (p = 0.001). At 2 years, there were 60% HRD cases and 88% HRP/HRU cases recurrence-free. At 5 years there were 29% HRD and 69% HRP/HRU cases recurrence-free (p = 0.001).

Conclusions

Despite a high rate of complete surgical staging and six cycles of adjuvant chemotherapy, recurrence rate was high in this early-stage cohort. Higher recurrence rates were seen in the HRD group, however these data are likely biased by the clinical practice of tumor testing primarily at the time of recurrence rather than the upfront setting. RFS was significantly lower for HRD cases.

Safety and efficacy of mirvetuximab soravtansine, a folate receptor alpha (FRα)-targeting antibody-drug conjugate (ADC), in combination with bevacizumab in patients with platinum-resistant ovarian cancer

PURPOSE

Evaluate the antitumor activity and safety profile of the combination of mirvetuximab soravtansine and bevacizumab in patients with platinum-resistant ovarian cancer.

METHODS

Patients with recurrent epithelial ovarian, fallopian tube, or primary peritoneal cancer, whose most recent platinum-free interval was ≤6 months, were administered mirvetuximab soravtansine (6 mg/kg adjusted ideal body weight) and bevacizumab (15 mg/kg), intravenously, once every 3 weeks. Eligibility included FRα expression by immunohistochemistry (IHC; ≥25% of cells with ≥2+ intensity). Prior bevacizumab and/or PARP inhibitor (PARPi) treatment were permitted. The primary endpoint was confirmed objective response rate (ORR). Secondary endpoints included duration of response (DOR), progression-free survival (PFS), and safety.

RESULTS

Ninety-four patients received combination treatment with mirvetuximab soravtansine and bevacizumab. Median age was 62 years (range, 39-81). Fifty-two percent had ≥3 prior therapies; 59% had prior bevacizumab; and 27% had prior PARPi. ORR was 44% (95% CI 33, 54) with 5 complete responses, median DOR 9.7 months (95% CI 6.9, 14.1), and median PFS 8.2 months (95% CI 6.8, 10.0). Treatment-related adverse events were consistent with the profiles of each agent, with the most common being blurred vision (all grades 57%; grade 3, 1%), diarrhea (54%; grade 3, 1%), and nausea (51%; grade 3, 1%).

CONCLUSION

The mirvetuximab soravtansine plus bevacizumab doublet is an active and well-tolerated regimen in patients with FRα-expressing platinum-resistant ovarian cancer. Promising activity was observed for patients regardless of level of FRα expression or prior bevacizumab. These data underscore the potential for mirvetuximab soravtansine as the combination partner of choice for bevacizumab in this setting.

Strategies for Prevention and Management of Ocular Events Occurring With Mirvetuximab Soravtansine

Mirvetuximab soravtansine (MIRV) is a first-in-class antibody-drug conjugate (ADC) targeting folate receptor alpha (FRα) and is indicated for the treatment of adult patients with FRα-positive, platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer who have received 1 to 3 prior systemic treatment regimens. MIRV has demonstrated single-agent anticancer activity in clinical trials, with a differentiated safety profile comprising primarily low-grade, resolvable gastrointestinal and ocular adverse events (AEs). Pooled safety analysis of 464 MIRV-treated patients across 3 trials, including the phase 2 SORAYA study, found that 50% of patients had ≥1 ocular AEs of interest (AEIs) of blurred vision or keratopathy, the majority being grade ≤2. Grade 3 ocular AEIs occurred in 5% of patients, and 1 patient (0.2%) had a grade 4 event of keratopathy. All grade ≥2 AEIs of blurred vision and keratopathy resolved to grade 1 or 0 in patients with complete follow-up data. MIRV-associated ocular AEs were primarily characterized by resolvable changes to the corneal epithelium, with no cases of corneal ulcers or perforations. This reflects the distinctive, milder ocular safety profile for MIRV compared with that of other ADCs with ocular toxicities in clinical use. To maintain a generally low incidence of severe ocular AEs, patients should follow recommendations for maintaining ocular surface health, including daily use of lubricating eye drops and periodic use of corticosteroid eye drops, and should undergo an eye examination at baseline, at every other cycle for the first 8 cycles of treatment, and as clinically indicated. Dose modification guidelines should be followed to maximize patients' ability to remain on therapy. Close collaboration between all care team members, including oncologists and eye care professionals, will help patients benefit from this novel and promising anticancer agent. This review focuses on the etiology, rates, prevention, and management of MIRV-associated ocular events.

Less is more: clinical utility of postoperative laboratory testing following minimally invasive hysterectomy for endometrial cancer

BACKGROUND

With the increasing rates of same-day discharge following minimally invasive surgery for endometrial cancer, the need for and value of routine postoperative testing is unclear.

OBJECTIVE

This study aimed to determine whether routine postoperative laboratory testing following minimally invasive hysterectomy for endometrial cancer leads to clinically significant changes in postoperative care.

STUDY DESIGN

This was a single-institution retrospective cohort study of patients undergoing minimally invasive hysterectomy for endometrial cancer by a gynecologic oncologist between June 2014 and June 2017. Patient demographics, preoperative comorbidities, operative and postoperative data, and pathologic findings were manually extracted from the patients' medical records. The financial burden of laboratory testing was computed using hospital-level cost data.

RESULTS

Of the 649 women included in the analysis, most (91.4%) were White, with a mean age of 61 years, and mean body mass index of 38.0 kg/m². The most common comorbidities were diabetes mellitus (31.9%, n=207), chronic pulmonary disease (7.9%, n=51), and congestive heart failure (3.2%, n=21). Median operative time was 151 minutes (range, 61-278), and median estimated blood loss was 100 mL (range, 10-1500). Most patients (68.6%, n=445) underwent lymphadenectomy. All patients had postoperative laboratory tests ordered: 100% complete blood count, 99.7% chemistry, 62.9% magnesium, 46.8% phosphate, 37.4% calcium, and 1.2% liver function tests. Twenty-six patients (4.0%) had a change in management owing to postoperative laboratory test results. Of these 26 women, 88% experienced a change in clinical status that would have otherwise prompted testing. Only 3 (0.5% of entire cohort) were asymptomatic: 1 received a blood transfusion for asymptomatic anemia, and the other 2, who did not carry a diagnosis of diabetes mellitus, had interventions for hyperglycemia. On univariable analysis, peripheral and cerebrovascular disease, diabetes mellitus with end-organ damage, and a Charlson Comorbidity Index of ≥3 were associated with increased odds of change in management; these were not significant on multivariable analysis. Routine postoperative laboratory evaluation in this cohort increased hospital costs by $292,000.

CONCLUSION

Routine postoperative laboratory tests are unlikely to lead to significant changes in management for women undergoing minimally invasive hysterectomy for endometrial cancer, and may increase cost without providing a discernible clinical benefit. In the setting of strict postoperative guidelines, laboratory tests should be ordered when clinically indicated rather than as part of routine postoperative management for women undergoing minimally invasive hysterectomy for endometrial cancer.

Phase III Randomized Trial of Maintenance Taxanes Versus Surveillance in Women With Advanced Ovarian/Tubal/Peritoneal Cancer: A Gynecologic Oncology Group 0212:NRG Oncology Study

PURPOSE

To compare taxane maintenance chemotherapy, paclitaxel (P) and paclitaxel poliglumex (PP), with surveillance (S) in women with ovarian, peritoneal, or fallopian tube (O/PC/FT) cancer who attained clinical complete response after first-line platinum-taxane therapy.

METHODS

Women diagnosed with O/PC/FT cancer who attained clinical complete response after first-line platinum-taxane-based chemotherapy were randomly allocated 1:1:1 to S or maintenance, P 135 mg/m2 once every 28 days for 12 cycles, or PP at the same dose and schedule. Overall survival (OS) was the primary efficacy end point.

RESULTS

Between March 2005 and January 2014, 1,157 individuals were enrolled. Grade 2 or worse GI adverse events were more frequent among those treated with taxane (PP: 20%, P: 27% v S: 11%). Grade 2 or worse neurologic adverse events occurred more often with taxane treatment (PP: 46%, P: 36% v S: 14%). At the fourth scheduled interim analysis, both taxane regimens passed the OS futility boundary and the Data Monitoring Committee approved an early release of results. With a median follow-up of 8.1 years, 653 deaths were reported; none were attributed to the study treatment. Median survival durations were 58.3, 56.8, and 60.0 months for S, P, and PP, respectively. Relative to S, the hazard of death for P was 1.091 (95% CI, 0.911 to 1.31; P = .343) and for PP, it was 1.033 (95% CI, 0.862 to 1.24; P = .725). The median times to first progression or death (PFS) were 13.4, 18.9, and 16.3 months for S, P, and PP, respectively. Hazard ratio = 0.801; 95% CI, 0.684 to 0.938; P = .006 for P and hazard ratio = 0.854; 95% CI, 0.729 to 1.00; P = .055 for PP.

CONCLUSION

Maintenance therapy with P and PP did not improve OS among patients with newly diagnosed O/tubal/peritoneal cancer, but may modestly increase PFS. GI and neurologic toxicities were more frequent in the taxane treatment arms.

A Randomized, Phase III Trial to Evaluate Rucaparib Monotherapy as Maintenance Treatment in Patients With Newly Diagnosed Ovarian Cancer (ATHENA-MONO/GOG-3020/ENGOT-ov45)

PURPOSE

ATHENA (ClinicalTrials.gov identifier: NCT03522246) was designed to evaluate rucaparib first-line maintenance treatment in a broad patient population, including those without BRCA1 or BRCA2 (BRCA) mutations or other evidence of homologous recombination deficiency (HRD), or high-risk clinical characteristics such as residual disease. We report the results from the ATHENA-MONO comparison of rucaparib versus placebo.

METHODS

Patients with stage III-IV high-grade ovarian cancer undergoing surgical cytoreduction (R0/complete resection permitted) and responding to first-line platinum-doublet chemotherapy were randomly assigned 4:1 to oral rucaparib 600 mg twice a day or placebo. Stratification factors were HRD test status, residual disease after chemotherapy, and timing of surgery. The primary end point of investigator-assessed progression-free survival was assessed in a step-down procedure, first in the HRD population (BRCA-mutant or BRCA wild-type/loss of heterozygosity high tumor), and then in the intent-to-treat population.

RESULTS

As of March 23, 2022 (data cutoff), 427 and 111 patients were randomly assigned to rucaparib or placebo, respectively (HRD population: 185 v 49). Median progression-free survival (95% CI) was 28.7 months (23.0 to not reached) with rucaparib versus 11.3 months (9.1 to 22.1) with placebo in the HRD population (log-rank P = .0004; hazard ratio [HR], 0.47; 95% CI, 0.31 to 0.72); 20.2 months (15.2 to 24.7) versus 9.2 months (8.3 to 12.2) in the intent-to-treat population (log-rank P < .0001; HR, 0.52; 95% CI, 0.40 to 0.68); and 12.1 months (11.1 to 17.7) versus 9.1 months (4.0 to 12.2) in the HRD-negative population (HR, 0.65; 95% CI, 0.45 to 0.95). The most common grade ≥ 3 treatment-emergent adverse events were anemia (rucaparib, 28.7% v placebo, 0%) and neutropenia (14.6% v 0.9%).

CONCLUSION

Rucaparib monotherapy is effective as first-line maintenance, conferring significant benefit versus placebo in patients with advanced ovarian cancer with and without HRD.

Clinical and molecular characteristics of ARIEL3 patients who derived exceptional benefit from rucaparib maintenance treatment for high-grade ovarian carcinoma

OBJECTIVE

ARIEL3 (NCT01968213) is a placebo-controlled randomized trial of the poly(ADP-ribose) polymerase inhibitor rucaparib as maintenance treatment in patients with recurrent high-grade ovarian carcinoma who responded to their latest line of platinum therapy. Rucaparib improved progression-free survival across all predefined subgroups. Here, we present an exploratory analysis of clinical and molecular characteristics associated with exceptional benefit from rucaparib.

METHODS

Patients were randomized 2:1 to receive rucaparib 600 mg twice daily or placebo. Molecular features (genomic alterations, BRCA1 promoter methylation) and baseline clinical characteristics were evaluated for association with exceptional benefit (progression-free survival ≥2 years) versus progression on first scan (short-term subgroup) and other efficacy outcomes.

RESULTS

Rucaparib treatment was significantly associated with exceptional benefit compared with placebo: 79/375 (21.1%) vs 4/189 (2.1%), respectively (p < 0.0001). Exceptional benefit was more frequent among patients with favorable baseline clinical characteristics and with carcinomas harboring molecular evidence of homologous recombination deficiency (HRD). A comparison between patients who derived exceptional benefit from rucaparib and those in the short-term subgroup revealed both clinical markers (no measurable disease at baseline, complete response to latest platinum, longer penultimate platinum-free interval) and molecular markers (BRCA1, BRCA2, RAD51C, and RAD51D alterations and genome-wide loss of heterozygosity) significantly associated with exceptional benefit.

CONCLUSIONS

Exceptional benefit in ARIEL3 was more common in, but not exclusive to, patients with favorable clinical characteristics or molecular features associated with HRD. Our results suggest that rucaparib can deliver exceptional benefit to a diverse set of patients with recurrent high-grade ovarian carcinoma.

Is there a "low-risk" patient population in advanced epithelial ovarian cancer?: a critical analysis

Ovarian cancer is the leading cause of gynecologic cancer-related death in the United States. Historically, studies have demonstrated that ovarian cancer is a heterogeneous disease with several patient and oncologic characteristics, including BRCA status and residual disease at surgery, known to be predictive of clinical outcomes. However, during the last decade, the discovery and approval of bevacizumab and poly(adenosine diphosphate-ribose) polymerase inhibitors have moved the frontline treatment paradigm beyond platinum-doublet therapy for women with advanced ovarian cancer. Subsequently, investigators have sought to assess the therapeutic efficacy of these agents in women who are considered "high" risk and "low" risk to determine which patients may benefit the most from aggressive therapy and in whom additional treatment may be avoided. We reviewed historic and contemporary definitions of "high-risk" and "low-risk" ovarian cancer and how this has been incorporated into the subset analyses of randomized, clinical trials of therapeutic agents, including bevacizumab and poly(adenosine diphosphate-ribose) polymerase inhibitors. Next, we provided an in-depth discussion of landmark trials for frontline maintenance therapy with bevacizumab and/or poly(adenosine diphosphate-ribose) polymerase inhibitors, focusing on the impact of treatment efficacy according to a "high-risk" and "low-risk" paradigm. Furthermore, we highlighted that recent data have challenged this dichotomous classification, notably from the Gynecologic Oncology Group-0218, ICON7, SOLO-1, and PAOLA-1 trials. Although some studies have suggested that certain populations of women with advanced ovarian cancer may have a more favorable prognosis and be considered "low risk," the risk of progression and death remains unacceptably high in all women. Furthermore, in many cases, those considered the lowest risk have the most treatment benefit from maintenance therapy with poly(adenosine diphosphate-ribose) polymerase inhibitors and/or bevacizumab. From these data, we have advocated that virtually all women with advanced ovarian cancer are high risk and that the use of our most effective therapies in the frontline setting holds promise for potentially curing more patients. Lastly, we critically discuss the practice of using subanalyses in clinical trials, with emphasis that although this practice is important for hypothesis generation, caution must be taken before accepting findings from subanalyses as actual treatment effects.

Quality-adjusted time without symptoms of disease or toxicity and quality-adjusted progression-free survival with niraparib maintenance in first-line ovarian cancer in the PRIMA trial

Background:

The PRIMA phase 3 trial showed niraparib significantly prolongs median progression-free survival (PFS) versus placebo in patients with advanced ovarian cancer (OC) responsive to first-line platinum-based chemotherapy, including those who had tumors with homologous recombination deficiency (HRd). This analysis of PRIMA examined the quality-adjusted PFS (QA-PFS) and quality-adjusted time without symptoms of disease or toxicity (Q-TWiST) of patients on maintenance niraparib versus placebo.

Methods:

Patients were randomized 2:1 to receive once-daily maintenance niraparib (n = 487) or placebo (n = 246). QA-PFS was defined as the PFS of patients adjusted for their health-related quality of life (HRQoL) prior to disease progression, measured using European Quality of Life Five-Dimension (EQ-5D) questionnaire index scores from the PRIMA trial. Q-TWiST was calculated by combining data on PFS, duration of symptomatic grade ⩾2 adverse events (fatigue or asthenia, nausea, vomiting, abdominal pain, and abdominal bloating) prior to disease progression, and EQ-5D index scores. Analyses used data collected up to the last date of PFS assessment (May 17, 2019).

Results:

The restricted mean QA-PFS was significantly longer with niraparib versus placebo in the HRd (n = 373) and overall intention-to-treat (ITT; n = 733) populations (mean gains of 6.5 [95% confidence interval; CI, 3.9–8.9] and 4.1 [95% CI, 2.2–5.8] months, respectively). There were also significant improvements in restricted mean Q-TWiST for niraparib versus placebo (mean gains of 5.9 [95% CI, 3.5–8.6] and 3.5 [95% CI, 1.7–5.6] months, respectively) in the HRd and ITT populations.

Conclusions:

In patients with advanced OC, first-line niraparib maintenance was associated with significant gains in QA-PFS and Q-TWiST versus placebo. These findings demonstrate that niraparib maintenance treatment is associated with a PFS improvement and that treatment benefit is maintained even when HRQoL and/or toxicity data are combined with PFS in a single measure.

Trial registration:

ClinicalTrials.gov: NCT02655016; trial registration date: January 13, 2016

Plain language summary

Background: In a large clinical trial called PRIMA, patients with advanced cancer of the ovary (ovarian cancer) were given either niraparib (a type of cancer medicine) or placebo (a pill containing no medicine/active substances) after having chemotherapy (another type of cancer medicine). Taking niraparib after chemotherapy is called maintenance therapy and aims to give patients more time before their cancer returns or gets worse than if they were not given any further treatment. In the PRIMA trial, patients who took niraparib did have more time before their cancer progressed than if they took placebo. However, it is important to consider patients’ quality of life, which can be made worse by cancer symptoms and/or side effects of treatment. Here, we assessed the overall benefit of niraparib for patients in PRIMA.

Methods: Both the length of time before disease progression (or survival time) and quality of life were considered using two different analyses:

● The first analysis was called quality-adjusted PFS (QA-PFS) and looked at how long patients survived with good quality of life.

● The second analysis was called quality-adjusted time without symptoms of disease or toxicity (Q-TWiST) and looked at how long patients survived without cancer symptoms or treatment side effects.

Results: The PRIMA trial included 733 patients; 487 took niraparib and 246 took placebo. Around half of the patients in both groups had a type of ovarian cancer that responds particularly well to drugs like niraparib – they are known as homologous recombination deficiency (HRd) patients.

● When information on quality of life (collected from patient questionnaires) and survival was combined in the QA-PFS analysis, HRd patients who took niraparib had approximately 6.5 months longer with a good quality of life before disease progression than those who took placebo. In the overall group of patients (including HRd patients and non-HRd patients), those who took niraparib had approximately 4 months longer than with placebo.

● Using the second analysis (Q-TWiST) to combine information on survival with cancer symptoms and treatment side effects, the HRd patients taking niraparib had approximately 6 months longer without cancer symptoms or treatment side effects (such as nausea or vomiting) than patients taking placebo. In the overall group of patients, those taking niraparib had approximately 3.5 months longer without these cancer symptoms/side effects than patients receiving placebo.

Conclusions: These results show that the survival benefits of niraparib treatment remain when accounting for patients’ quality of life. These benefits were seen not only in HRd patients who are known to respond better to niraparib, but in the overall group of patients who took niraparib.

Health-related quality of life with pembrolizumab monotherapy in patients with previously treated advanced microsatellite instability high/mismatch repair deficient endometrial cancer in the KEYNOTE-158 study

OBJECTIVE

Pembrolizumab demonstrated a clinically meaningful objective response rate in patients with previously treated, advanced MSI-H/dMMR endometrial cancer in the multicohort phase 2 KEYNOTE-158 study (ClinicalTrials.gov, NCT02628067). We present health-related quality of life (HRQoL) results for these patients.

METHODS

This analysis included patients from cohorts D (endometrial cancer with any MSI status) and K (any MSI-H/dMMR solid tumor except colorectal) who had previously treated, advanced MSI-H/dMMR endometrial cancer. Patients received pembrolizumab 200 mg Q3W for 35 cycles. EORTC QLQ-C30 and EQ-5D-3L questionnaires were administered at baseline, at regular intervals during treatment, and 30 days after treatment discontinuation. Pre-specified exploratory analyses included changes from baseline to week 9 in QLQ-C30 global health status (GHS)/QoL and EQ-5D-3L visual analog scale (VAS) score for all patients and by best overall response.

RESULTS

84 of 90 enrolled patients completed ≥1 HRQoL questionnaire and were included in the analysis. QLQ-C30 and EQ-5D-3L compliance rates were 90% and 94%, respectively, at baseline, and 92% and 93% at week 9. Mean (95% CI) QLQ-C30 GHS/QoL scores improved from baseline to week 9 by 6.08 (0.71-11.46) points in the overall population, with greater improvement in patients who achieved complete or partial response (11.67 [5.33-18.00]-point increase). Mean (95% CI) EQ-5D-3L VAS scores improved by 6.00 (2.25-9.75) points in the overall population and 9.11 (5.24-12.98) points in patients with CR/PR.

CONCLUSIONS

Pembrolizumab maintained or improved HRQoL in patients with previously treated, advanced MSI-H/dMMR endometrial cancer, further supporting efficacy and safety results from KEYNOTE-158 and pembrolizumab use in this setting.

Efficacy of niraparib by time of surgery and postoperative residual disease status: A post hoc analysis of patients in the PRIMA/ENGOT-OV26/GOG-3012 study

OBJECTIVE

To evaluate the association between surgical timing and postoperative residual disease status on the efficacy of niraparib first-line maintenance therapy in patients with newly diagnosed advanced ovarian cancer at high risk of recurrence.

METHODS

Post hoc analysis of the phase 3 PRIMA/ENGOT-OV26/GOG-3012 (NCT02655016) study of niraparib in patients with newly diagnosed primary advanced ovarian, primary peritoneal, or fallopian tube cancer with a complete/partial response to first-line platinum-based chemotherapy. Progression-free survival (PFS) was assessed by surgical status (primary debulking surgery [PDS] vs neoadjuvant chemotherapy/interval debulking surgery [NACT/IDS]) and postoperative residual disease status (no visible residual disease [NVRD] vs visible residual disease [VRD]) in the intent-to-treat population.

RESULTS

In PRIMA (N = 733), 236 (32.2%) patients underwent PDS, and 481 (65.6%) received NACT/IDS before enrollment. Median PFS (niraparib vs placebo) and hazard ratios (95% CI) for progression were similar in PDS (13.7 vs 8.2 months; HR, 0.67 [0.47-0.96]) and NACT/IDS (14.2 vs 8.2 months; HR, 0.57 [0.44-0.73]) subgroups. In patients who received NACT/IDS and had NVRD (n = 304), the hazard ratio (95% CI) for progression was 0.65 (0.46-0.91). In patients with VRD following PDS (n = 183) or NACT/IDS (n = 149), the hazard ratios (95% CI) for progression were 0.58 (0.39-0.86) and 0.41 (0.27-0.62), respectively. PFS was not evaluable for patients with PDS and NVRD because of sample size (n = 37).

CONCLUSIONS

In this post hoc analysis, niraparib efficacy was similar across PDS and NACT/IDS subgroups. Patients who had NACT/IDS and VRD had the highest reduction in the risk of progression with niraparib maintenance.

ATHENA–MONO (GOG-3020/ENGOT-ov45): A randomized, double-blind, phase 3 trial evaluating rucaparib monotherapy versus placebo as maintenance treatment following response to first-line platinum-based chemotherapy in ovarian cancer

LBA5500

Background: While PARP inhibitors have shown efficacy as first-line (1L) maintenance treatment for patients (pts) with ovarian cancer (OC), questions remain about the pt population that may benefit from their use. ATHENA (NCT03522246) was designed to test if rucaparib may be effective as 1L maintenance treatment in a broad pt population, including those without BRCA mutations or other evidence of homologous recombination deficiency (HRD), or high-risk clinical characteristics such as residual disease. Here we report results from the ATHENA–MONO comparison of rucaparib vs placebo. Methods: Pts with stage III–IV high-grade OC who had completed cytoreductive surgery (R0 permitted) and 4–8 cycles of 1L platinum-doublet (bevacizumab allowed with chemotherapy) with a response were randomized 4:1 to oral rucaparib 600 mg BID or placebo. Pts were stratified by HRD status (as determined by FoundationOne CDx), residual disease status after chemotherapy, and timing of surgery. The primary endpoint of investigator-assessed PFS per RECIST was assessed in a step-down procedure first in the HRD population (BRCA mutant or BRCA wild-type/loss of heterozygosity [LOH] high carcinoma) and then in the intent-to-treat (ITT) population. Blinded independent central review (BICR)–assessed PFS was a stand-alone, secondary endpoint. PFS in BRCA mutant and HRD-negative pts (BRCA wild-type/LOH low) were exploratory endpoints. Results: As of Mar 23, 2022 (visit cutoff), 427 and 111 pts were randomized to rucaparib monotherapy or placebo (median time on treatment, 14.7 and 9.9 mo). PFS data are shown in the Table. Most common grade ≥3 TEAEs were anemia (rucaparib, 28.7% vs placebo, 0%), neutropenia (14.6% vs 0.9%), and ALT/AST increased (10.6% vs 0.9%). Rucaparib dose reduction, interruption, and discontinuation due to TEAEs occurred in 49.4%, 60.7%, and 11.8% of pts. Conclusions: Rucaparib monotherapy is effective as 1L maintenance with significant benefit vs placebo observed in the ITT and HRD populations, as well as the non-nested subgroup of pts without known HRD. Clinical trial information: NCT03522246. [Table: see text]

ENGOT-ov60/GOG-3052/RAMP 201: A phase 2 study of VS-6766 (RAF/MEK clamp) alone and in combination with defactinib (FAK inhibitor) in recurrent low-grade serous ovarian cancer (LGSOC)

TPS5615

Background: Low-grade serous ovarian cancer (LGSOC) constitutes up to 10% of all ovarian cancer and has clinical and molecular characteristics distinct from high-grade serous ovarian cancer. Approximately a third of patients (pts) with recurrent LGSOC harbor KRAS mutations (mt) and pts with KRAS wild-type (wt) LGSOC may have mutations in NRAS, BRAF, or other RAS pathway-associated genes. Prior clinical studies with single agent MEK inhibitors have shown response rates of 16-26% in recurrent LGSOC. VS-6766 is a unique small molecule RAF/MEK clamp that inhibits both RAF and MEK activities by trapping them in inactive complexes. This mechanism of blockade has been shown to limit compensatory MEK activation, thereby potentially enhancing efficacy of MEK inhibition. Focal adhesion kinase (FAK) activation is a putative resistance mechanism to RAF and MEK inhibition, and defactinib, a small molecule inhibitor of FAK, has shown synergistic anti-tumor activity with VS-6766 in preclinical models, including organoids from LGSOC pts. Furthermore, FAK inhibition combined with VS-6766 induces tumor regression in a KRAS mt ovarian cancer xenograft model. The combination of VS-6766 and defactinib is currently being evaluated in the ongoing Investigator Sponsored FRAME study (NCT03875820). In this proof-of-concept study, durable objective responses (ORR = 46%; 11/24) have been reported in recurrent LGSOC pts, including pts who have had a prior MEK inhibitor (Banerjee ESMO 2021) and the combination of VS-6766 + defactinib has received FDA Breakthrough Therapy Designation for recurrent LGSOC. These initial preclinical and clinical results support the ongoing phase 2 ENGOT-ov60/GOG-3052 in recurrent LGSOC. Methods: This is an international phase 2, adaptive, multicenter, randomized, open label study designed to evaluate the efficacy and safety of VS-6766 vs VS-6766 in combination with defactinib currently open to enrollment (NCT04625270). The study will be conducted in two parts. Part A will determine the optimal regimen based on confirmed overall response rate (independent radiology review) in KRAS mt and KRAS wt LGSOC. Part B will determine the efficacy of the optimal regimen identified in Part A in KRAS mt and KRAS wt LGSOC. The minimum expected enrollment is 104 pts, 52 pts with KRAS mt and 52 KRAS wt (64 pts in Part A and 40 pts in Part B). Pts will be randomized to receive VS-6766 (4.0 mg orally (PO), twice weekly 3 wks on, 1 wk off) or VS-6766 with defactinib (VS-6766 3.2 mg PO, twice weekly + defactinib 200 mg PO BID 3 wks on, 1 wk off) till progression. Key inclusion criteria include histologically confirmed LGSOC, known KRAS mutation status, prior systemic therapy including platinum for metastatic disease and up to 1 prior line of MEK inhibitor therapy permitted. Part A of this study has completed enrollment and Part B is currently enrolling pts. Clinical trial information: NCT04625270.

Efficacy and safety of rucaparib maintenance treatment in patients from ARIEL3 with platinum-sensitive, recurrent ovarian carcinoma not associated with homologous recombination deficiency

5544

Background: In ARIEL3 (NCT01968213), rucaparib maintenance treatment led to significant improvement vs placebo for the primary endpoint of investigator-assessed progression-free survival (PFS) in patients (pts) with platinum-sensitive, recurrent ovarian carcinoma responsive to the last line of platinum therapy (Coleman et al. Lancet. 2017;390:1949–61). The largest benefit was observed in pts with carcinomas with a BRCA mutation or high loss of heterozygosity (LOH), a marker of homologous recombination deficiency (HRD). However, rucaparib also improved PFS in pts with carcinomas negative by HRD test (ie, BRCA wild-type with low LOH), a subset of pts for which there is no identified molecular mechanism conferring PARP inhibitor sensitivity. Among these pts (rucaparib, n = 107; placebo, n = 54), median PFS was 6.7 vs 5.4 months, respectively (HR, 0.58 [95% CI 0.40–0.85]; P= 0.0049), and 31.8% vs 4.3% were progression-free at 1 yr. In this post hoc exploratory analysis, we further evaluated the efficacy of rucaparib maintenance vs placebo in this subset of pts. Methods: Pts were randomized 2:1 to oral rucaparib (600 mg BID) or placebo. For this analysis, investigator-assessed PFS and safety were evaluated in pts with HRD-negative carcinoma, defined as BRCA wild-type with genomic LOH < 16% using Foundation Medicine’s T5 NGS assay. Results: Visit cutoff dates for efficacy and safety were Apr 15, 2017, and Dec 31, 2019. Across subgroups based on demographic or disease characteristics, the trend of rucaparib benefit vs placebo was consistently observed in pts with HRD-negative carcinoma (Table). The safety profile of rucaparib in the HRD-negative population was consistent with that of the overall safety population reported previously. Conclusions: Rucaparib maintenance reduced risk of progression in pts with ovarian carcinomas, including those not associated with HRD, regardless of clinical prognostic factors. [Table: see text]

ARTISTRY-7: A phase 3, multicenter study of nemvaleukin alfa in combination with pembrolizumab versus chemotherapy in patients (pts) with platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer

TPS5609

Background: ARTISTRY-7 will evaluate the novel engineered cytokine nemvaleukin alfa (nemvaleukin, ALKS 4230) in pts with gynecologic cancers. Epithelial ovarian cancer (OC) is the 7th most common cause of cancer mortality in women. OC is an area of high unmet need, as many pts become resistant or refractory to frontline platinum-based chemotherapy. Nemvaleukin was designed to selectively bind to the intermediate-affinity interleukin-2 (IL-2) receptor, preferentially activating and expanding antitumor CD8+ T and NK cells with minimal expansion of Tregs. This selectivity may provide enhanced tumor killing and improved safety/tolerability compared with high-dose IL-2. In clinical studies, nemvaleukin, as monotherapy and in combination with pembrolizumab, has shown evidence of clinical benefit in multiple tumor types, including OC. In ARTISTRY-1, 4 responses were observed in pts with OC, including 2 complete responses, 1 in a pt with platinum-resistant OC and 5 prior lines of therapy, and 2 partial responses. Methods: ARTISTRY-7 is a phase 3, multicenter, open-label randomized study of nemvaleukin and/or pembrolizumab vs chemotherapy. Eligible pts are women (≥18 y) with histologically confirmed epithelial OC (high-grade serous, endometrioid, clear cell), fallopian tube cancer, or primary peritoneal cancer. Pts must have received ≥1 prior line of systemic therapy in the platinum-sensitive setting, ≤5 prior lines in the platinum-resistant setting, and prior bevacizumab, with radiographic progression on most recent therapy. Primary platinum-refractory disease (progression on first-line platinum therapy) or primary platinum resistance (progression < 3 months after completion of first-line platinum therapy) is exclusionary. Pts must have ECOG performance status of 0 or 1, estimated life expectancy of ≥3 months, and adequate hematologic reserve and hepatic and renal function. Approximately 376 pts will be randomized (3:1:1:3) to receive nemvaleukin 6 μg/kg IV on days 1-5 and pembrolizumab 200 mg IV on day 1 of each 21-day cycle, pembrolizumab monotherapy, nemvaleukin monotherapy, or chemotherapy (pegylated liposomal doxorubicin, paclitaxel, topotecan, or gemcitabine) and stratified according to PD-L1 status, histologic subtype (high-grade vs non–high-grade serous), and chemotherapy (paclitaxel vs other). Pts will continue treatment until disease progression or intolerable toxicity (maximum 35 cycles for pembrolizumab; nemvaleukin can be continued). The primary endpoint is investigator-assessed PFS (RECIST v1.1) in the nemvaleukin/pembrolizumab vs chemotherapy group. Secondary/exploratory endpoints include overall survival, other antitumor measures, safety, health-related quality of life, and pharmacokinetic/pharmacodynamic effects. Clinical trial information: NCT05092360.

ROSELLA: A phase 3 study of relacorilant in combination with nab-paclitaxel versus investigator’s choice in advanced, platinum-resistant, high-grade epithelial ovarian, primary peritoneal, or fallopian-tube cancer

TPS5620

Background: Chemotherapy resistance is a major concern in the treatment of advanced platinum-resistant and platinum-refractory ovarian cancer. One mechanism of resistance is driven by cortisol, which can suppress the apoptotic pathways that chemotherapy agents rely upon, eg, suppression of BCL2 and FOXO3a pathways. Preclinical and clinical data indicate that glucocorticoid receptor (GR) antagonism may reverse the anti-apoptotic effects of cortisol, thereby restoring the efficacy of cytotoxic agents. Relacorilant is a selective GR modulator that has shown promise in overcoming resistance when combined with taxanes (particularly nab-paclitaxel) in preclinical models (Greenstein & Hunt 2021) and early-phase clinical studies (Munster et al. 2019) in various solid tumors. A randomized, controlled phase 2 study of relacorilant + nab-paclitaxel found clinically meaningful improvements in progression-free survival (PFS) and duration of response (DOR) without increased side effect burden in patients with recurrent, platinum-refractory and platinum-resistant ovarian cancer (Colombo et al. 2021). The aim of this phase 3 study is to confirm these phase 2 findings in a larger patient population. Methods: ROSELLA (EudraCT 2022-000662-18, NCT pending) is a phase 3, randomized, 2-arm, open-label, multicenter study of relacorilant + nab-paclitaxel compared to investigator’s choice of chemotherapy agents in patients with confirmed high-grade serous epithelial ovarian, primary peritoneal, or fallopian tube cancer. The trial is being conducted at multiple sites in North America and Europe and has a planned enrollment of 360 patients. Patients are randomized 1:1 to either relacorilant (150 mg the day before, day of, and day after nab-paclitaxel infusion) + nab-paclitaxel (80 mg/m2 on days 1, 8, and 15 of each 28-day cycle) or investigator’s choice of chemotherapy (liposomal doxorubicin, paclitaxel, topotecan, or nab-paclitaxel). Randomization is stratified by prior lines of therapy (1 vs > 1), region of world (North America vs Europe), and prior bevacizumab (yes/no). Adult female patients with platinum-resistant disease (progression within 6 months of completion of platinum-containing therapy), excluding patients with primary platinum refractory disease, who have received 1–3 lines of prior systemic anticancer therapy and at least 1 prior line of platinum therapy are being enrolled. Life expectancy ≥3 months, adequate organ function, and ECOG performance status of 0 or 1 are required. The primary study endpoint is PFS by blinded independent central review. Key secondary endpoints include overall survival, PFS by investigator, overall response rate, best overall response, DOR, clinical benefit rate, safety, quality of life, CA-125, pharmacodynamics, and pharmacokinetics. Clinical trial information: 2022-000662-18.

FLORA-5/GOG3035: Frontline chemo-immunotherapy (paclitaxel-carboplatin-oregovomab [PCO] versus chemotherapy (paclitaxel-carboplatin-placebo [PCP]) in patients with advanced epithelial ovarian cancer (EOC)—Phase III, double-blind, placebo-controlled, global, multinational study

TPS5619

Background: Oregovomab, a murine IgGκ1 monoclonal antibody, has high affinity binding to tumor associated antigen CA125, thus, rendering the target antigen CA125 more immunogenic or “neoantigen-like” through altered and enhanced antigen processing and presentation to specific T cells. This phenomenon is hypothesized to bypass tumor-associated immune suppression when oregovomab is combined with chemotherapy. In a randomized phase II study, oregovomab in combination with paclitaxel and carboplatin (PC) induced tumor immunity and demonstrated significant improvement in median PFS (41.8 months(m) PCO vs 12.2 m PC, HR 0.46, p=0.0027) and median OS (N.E. PCO vs 43.2 m PC, HR O.35, p=0.043) in patients with previously untreated EOC. Oregovomab combined with PC had a favorable toxicity profile. FLORA-5/GOG3035, the definitive confirmatory global registration trial, is currently recruiting patients in the front-line setting. Methods: The study is a phase 3, multicenter, double-blind, placebo-controlled trial. Optimally debulked patients with FIGO III/IV EOC and serum CA125 ≥ 50 U/ml receiving adjuvant (Cohort 1) or patients receiving neoadjuvant chemotherapy post-interval cytoreductive surgery (Cohort 2) will be randomized to PC + oregovomab or placebo (PCO vs. PCP). Patients with germline BRCA1/2 mutations are excluded. Chemotherapy will be administered every 3 weeks in both cohorts. Oregovomab/placebo is administered simultaneously at cycles 1, 3, and 5 of chemotherapy with an additional dose at 12 weeks following cycle 5 in Cohort 1. Neoadjuvant patients will be administered oregovomab/placebo after debulking surgery at cycles 4 and 6 with two additional doses at 6- and 18-weeks following cycle 6 in Cohort 2. No other front-line maintenance therapy is permitted. The primary objective is PFS determined by RECIST 1.1. Cohort 1 will recruit 372 patients with a 90% power to detect a difference with an alpha of 0.025 and a hazard ratio of 0.65 when 252 PFS events have been observed. Cohort 2 will be analyzed separately recruiting 232 patients with a 90% power to detect a difference with an alpha of 0.025 and a hazard ratio of 0.60 when 165 PFS events have been observed. An interim futility analysis will be performed. Secondary objectives include OS, frequency and severity of AEs, and QoL. Exploratory objectives include iRECIST, TFST, TSST, PFS2, and evaluation of correlative biomarkers. The study is actively enrolling in the US, Canada, Belgium, Italy, Spain, Czech Republic, Hungary, Poland, Korea, Taiwan, Mexico, Argentina, and Chile. 179 patients were enrolled at time of submission. Clinical trial information: NCT04498117.

Integrated safety summary of single-agent mirvetuximab soravtansine in patients with folate receptor α (FRα)-positive recurrent ovarian cancer: Phase 1 and 3 clinical trials

5574

Background: Available chemotherapies for platinum-resistant ovarian cancer (PROC) have limited clinical activity and considerable toxicity. Mirvetuximab soravtansine (MIRV) is a first-in-class antibody drug conjugate (ADC) comprising a folate receptor alpha (FRα)-binding antibody, cleavable linker, and the maytansinoid payload DM4, a potent tubulin-targeting agent that has demonstrated significant anti-tumor activity in this difficult to treat population. The objective is to characterize the tolerability profile of MIRV in a pooled analysis of experience when administered as monotherapy in patients (pts) with FRα positive recurrent ovarian cancer. Methods: Retrospective pooled analysis included pts enrolled across three studies: phase 1 first-in-human, phase 3 FORWARD I, and phase 3 SORAYA. Analysis included pts with FRα positive recurrent ovarian cancer and those pts with low, medium, and high FRα expression by immunohistochemistry (Roche FOLR1 Assay ≥ 25% of cells with PS2+ staining intensity). All pts received intravenous MIRV at 6 mg/kg, adjusted ideal body weight, on Day 1 of a 21-day cycle until disease progression or unacceptable toxicity. Results: 464 pts were included from 15 countries, with key characteristics: median age 63 yrs, 87% 1-3 prior therapies, 91% platinum free interval ≤6 months, 65% prior bevacizumab, and 25% prior PARPi. The most common treatment-related adverse events (TRAE) (all grade, grade 3+) included blurred vision (42%, 3%), nausea (40%, 2%), diarrhea (33%, 2%), fatigue (31%, 2%), keratopathy (26%, 3%), and dry eye (22%, 1%). TRAEs leading to a dose delay or reduction occurred in 33% and 21% of pts, respectively. Seven % discontinued due to a TRAE. Four pts ( < 1%) discontinued MIRV due to an ocular event. Ninety % of pts with a grade 2+ blurred vision resolved to grade 0 or 1, 93% of pts with grade 2+ keratopathy resolved to grade 0 or 1. No corneal ulcers or perforation have been reported and no patient with a serious ocular event has been reported to have permanent sequelae. Conclusions: In a pooled analysis of 464 patients, MIRV monotherapy has a differentiated and predictable safety profile consisting primarily of low grade and reversible gastrointestinal and ocular events. These events were managed with supportive care and dose modifications if needed, with a low rate of treatment-related discontinuation. The safety profile of MIRV in recurrent ovarian cancer along with the anti-tumor activity in PROC (32.4% ORR Matulonis SGO 2022) support a favorable benefit/risk in this population. Clinical trial information: NCT01609556, NCT04296890, NCT02631876.

Real-world use, tolerability, and dose modifications of PARP inhibitors in ovarian cancer

5552

Background: Tolerability is a key consideration when selecting a PARP inhibitor (PARPi) for ovarian cancer (OC). Here we expand on earlier work (Arend et al 2021) to further characterize real-world tolerability and dose modifications in US patients (pts) with OC receiving PARPi therapy. Methods: A retrospective cohort of OC pts starting olaparib (ola), niraparib (nir) or rucaparib (ruc) between Jan 2017 and Dec 2020 was identified from MarketScan® Commercial/Medicare Supplemental databases, increasing the period covered and number of pts included vs our previous analysis. Pts were followed up from first PARPi prescription (index) for ≥30 days until end of study period, disenrollment or death; baseline was 6 months pre-index. Clinical events of interest (CEIs; acute myeloid leukemia/myelodysplastic syndromes, anemia, leukopenia/neutropenia, thrombocytopenia, acute kidney injury, arthralgia, constipation, diarrhea, nausea, vomiting, dermatitis/rash/photosensitivity, fatigue, hypertension, infection, insomnia, pneumonitis, transaminitis) were identified via ICD-9/10 codes. Multivariable Cox regression compared the likelihood of CEIs, dose modifications and hospitalizations between PARPis, adjusting for baseline CEI, Charlson Comorbidity Index score, prior bevacizumab and cancer-related surgery. Persistence was defined as no PARPi treatment gaps of >90 days in pts with ≥6 months’ continuous enrollment. Results: Overall, 637, 538 and 227 pts received ola, nir and ruc, respectively (median [IQR] follow-up 10.5 [13.4] months). Baseline characteristics were similar across groups. The proportion of pts initiating PARPi at the highest indicated dose was 89.2%, 57.6% and 89.9% for ola, nir and ruc, respectively; 22.6%, 34.8% and 28.6%, respectively, required dose decreases. The likelihood of experiencing CEIs varied across the PARPis after adjusting for a priori confounders as shown in the table. Persistence with index PARPi was higher with ola (83.4%) vs nir (73.3%; P<0.001) and similar vs ruc (80.2%; P>0.05). Among all pts, mean time to non-persistence was shorter with nir vs ola and ruc (6.4 vs 7.9 and 7.6 months, respectively; both P<0.05). CEIs by PARPi dose and calendar year will also be presented. Conclusions: This is the largest real-world comparison of PARPi use in OC pts reported to date. It supports differences between PARPis in persistence with therapy and risk of experiencing a CEI, even after adjusting for confounders. [Table: see text]