Abstract CT172: A phase 2 multicenter study to evaluate the efficacy and safety using autologous tumor infiltrating lymphocytes (LN-145) in patients with recurrent metastatic or persistent cervical carcinoma

Adoptive cell therapy (ACT) may be effective in treating immunogenic tumors with high mutational load, such as melanoma, and virally-associated tumors, like cervical cancer, with several patients in studies performed at various institutions achieving durable, complete responses for years. HPV infection increases mutational load, thus providing additional neoantigen targets ideal for the polyclonal nature of ACT. As outcomes for patients with recurrent, metastatic or persistent cervical cancer remain extremely poor, there is an enormous need for novel immunotherapeutic approaches with curative potential such as ACT.

Clinical trial C-145-04 (NCT03108495) is a prospective, phase II multicenter, open-label study evaluating the efficacy of a single autologous tumor infiltrating lymphocyte infusion (LN-145) followed by IL-2 after a non-myeloablative lymphodepletion (NMA-LD) regimen in patients with recurrent, metastatic, or persistent cervical cancer, who have failed at least one prior systemic therapy. The clinical trial requires resection of an adequate size tumor lesion, which is then shipped to a central GMP manufacturing facility for tumor infiltrating lymphocyte (TIL) extraction, expansion, and preparation of the final infusion product (LN-145). One week prior to LN-145 shipment and infusion, patients undergo NMA-LD consisting of cyclophosphamide (60 mg/kg) daily x 2 days followed by fludarabine (25 mg/m2) daily x 5 days. LN-145 is infused 24 hours after the last dose of fludarabine followed by up to 6 doses of IL-2 (600,000 IU/kg) every 8-12 hours. The primary endpoint is the ORR per RECIST v1.1. Secondary endpoints include complete response, duration of response, disease control rate, progression free- and overall survival and safety. Patients must, in addition to the tumor targeted for excision for TIL manufacture, have an additional measurable lesion for assessment of response. Other major eligibility criteria include: adequate bone marrow, liver, pulmonary, cardiac and renal function; ECOG performance status of 0 or 1. Systemic steroids greater than 10 mg/day prednisone equivalents are prohibited as are a history of serious immunotherapy-related adverse events.

Citation Format: Amir Jazaeri, Robert Edwards, Robert Wenham, Koji Matsuo, Gini F. Fleming, David M. O'Malley, Brian Slomovitz, Bradley Monk, Robert J. Brown, Sam Suzuki, Igor Gorbatchevsky, Maria Fardis, Emese Zsiros. A phase 2 multicenter study to evaluate the efficacy and safety using autologous tumor infiltrating lymphocytes (LN-145) in patients with recurrent metastatic or persistent cervical carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr CT172.

Randomized Phase II Trial of Carboplatin-Paclitaxel Versus Carboplatin-Paclitaxel-Trastuzumab in Uterine Serous Carcinomas That Overexpress Human Epidermal Growth Factor Receptor 2/neu

Purpose Uterine serous carcinoma is a rare, aggressive variant of endometrial cancer. Trastuzumab is a humanized monoclonal antibody that targets human epidermal growth factor receptor 2 (HER2)/neu, a receptor overexpressed in 30% of uterine serous carcinoma. This multicenter, randomized phase II trial compared carboplatin-paclitaxel with and without trastuzumab in patients with advanced or recurrent uterine serous carcinoma who overexpress HER2/neu. Methods Eligible patients had primary stage III or IV or recurrent HER2/neu-positive disease. Participants were randomly assigned to receive carboplatin-paclitaxel (control arm) for six cycles with or without intravenous trastuzumab (experimental arm) until progression or unacceptable toxicity. The primary end point was progression-free survival, which was assessed for differences between treatment arms via one-sided log-rank tests. Results From August 2011 to March 2017, 61 patients were randomly assigned. Forty progression-free survival-related events occurred among 58 evaluable participants. Among all patients, median progression-free survival was 8.0 months (control) versus 12.6 months (experimental; P = .005; hazard ratio [HR], 0.44; 90% CI, 0.26 to 0.76). Similarly, median progression-free survival was 9.3 (control) versus 17.9 (experimental) months among 41 patients with stage III or IV disease undergoing primary treatment ( P = .013; HR, 0.40; 90% CI, 0.20 to 0.80) and 6.0 (control) versus 9.2 months (experimental), respectively, among 17 patients with recurrent disease ( P = .003; HR, 0.14; 90% CI, 0.04 to 0.53). Toxicity was not different between treatment arms, and no unexpected safety signals emerged. Conclusion Addition of trastuzumab to carboplatin-paclitaxel was well tolerated and increased progression-free survival. These encouraging results deserve further investigation to determine their impact on overall survival in patients with advanced or recurrent uterine serous carcinoma who overexpress HER2/neu.

A review of mirvetuximab soravtansine in the treatment of platinum-resistant ovarian cancer

Resistance to platinum-based therapy poses a significant clinical challenge for the management of advanced ovarian cancer, a leading cause of cancer mortality among women. Mirvetuximab soravtansine is a novel antibody–drug conjugate that targets folate receptor-α, a validated molecular target for therapeutic intervention in this disease. Here, we examine mirvetuximab soravtansine's mechanism of action and pharmacology, and review its clinical evaluation in ovarian cancer to date. We focus on the favorable tolerability and encouraging signals of efficacy that have emerged, most notably in patients with platinum-resistant disease. Ongoing Phase III monotherapy and Phase Ib/II combination trials evaluating its activity in the setting of platinum resistance are emphasized, which will help define its role in the evolving landscape of ovarian cancer therapy.

Abstract LB-A12: Results from the phase 3 study ARIEL3: mutations in non-BRCA homologous recombination repair genes confer sensitivity to maintenance treatment with the PARP inhibitor rucaparib in patients with recurrent platinum-sensitive high-grade ovarian carcinoma

Background: High-grade ovarian carcinomas (HGOC) with a mutation in BRCA1/2 or other core homologous recombination repair (HRR) genes are sensitive to treatment with the PARP inhibitor rucaparib. To study whether HRR gene mutations confer sensitivity to rucaparib in the maintenance setting, we performed next-generation sequencing (NGS) on carcinomas from a double-blind, placebo-controlled, phase 3 study of rucaparib in patients with HGOC following response to platinum-based chemotherapy (ARIEL3, NCT01968213). Materials and Methods: Archival ovarian carcinoma specimens were required for all 564 patients who were randomized in ARIEL3 and were sequenced using Foundation Medicine’s NGS-based assay to identify deleterious mutations in a prespecified list of HRR genes (BRCA1/2 and 28 non-BRCA HRR genes, including ATM, BARD1, BRIP1, CHEK2, RAD51C, RAD51D, RAD54L, and FANC family genes). Patients were randomized 2:1 to receive oral rucaparib 600 mg twice daily or placebo. The randomization was stratified by HRR gene mutation status (BRCA, non-BRCA HRR, no mutation in BRCA or HRR gene), progression-free interval of the penultimate platinum-based regimen, and best response to most recent platinum regimen. The primary endpoint for ARIEL3 was investigator-assessed progression-free survival (PFS) per RECIST v1.1. Exploratory analysis of confirmed response was conducted for the subgroup of patients with measurable disease at study entry. Results: Deleterious mutations in non-BRCA HRR genes were detected in ovarian carcinoma specimens from 7.6% (43/564) of randomized patients. In these patients, PFS was significantly longer with rucaparib than with placebo (hazard ratio [HR], 0.21; 95% confidence interval [CI], 0.09-0.50; P=0.0005), with a median PFS of 11.1 mo and 5.5 mo, respectively. This HR is similar to that found in women with carcinomas containing a BRCA1/2 mutation (0.23; 95% CI, 0.16-0.34). The most commonly found non-BRCA HRR gene mutations among the 28 patients in the rucaparib arm were RAD51C (n=6) and RAD51D (n=4) and among the 15 patients in the placebo arm were BRIP1 (n=5) and RAD51C (n=2). A diverse set of mutation types were detected, including frameshift insertions/deletions, homozygous deletions, and nonsense and splice site mutations. All 10 RAD51C/D mutations were homozygous within the carcinomas, indicating biallelic loss. Additionally, all RAD51C/D-mutant carcinomas exhibited high genomic loss of heterozygosity, which is a type of genomic scar characteristic of HRR deficiency. At the visit cutoff date (15 April 2017), only 2 of the 10 RAD51C/D cases in the rucaparib arm had disease progression; 7 had a PFS duration of at least 1 y (median PFS, 16.4 mo; range 5.4+ to 30.4+ mo). Three of the RAD51C/D cases were in the subgroup of patients who had measurable disease at baseline, and all achieved a confirmed response (1 complete response and 2 partial responses). In comparison, the 3 RAD51C/D cases in the placebo arm had a median PFS of 5.4 mo (range, 3.9 to 5.5 mo). Conclusions: Patients with recurrent platinum-sensitive HGOC harboring a deleterious mutation in non-BRCA HRR genes (including RAD51C/D) had significantly longer PFS with rucaparib maintenance treatment than with placebo.

Citation Format: David M. O'Malley, Robert L. Coleman, Amit M. Oza, Domenica Lorusso, Carol Aghajanian, Ana Oaknin, Andrew Dean, Nicoletta Colombo, Iain A. McNeish, Elizabeth M. Swisher, Clare L. Scott, Gottfried E. Konecny, Heidi Giordano, Terri Cameron, Lara Maloney, Sandra Goble, James Sun, Thomas C. Harding, Kevin K. Lin, Jonathan A. Ledermann. Results from the phase 3 study ARIEL3: mutations in non-BRCA homologous recombination repair genes confer sensitivity to maintenance treatment with the PARP inhibitor rucaparib in patients with recurrent platinum-sensitive high-grade ovarian carcinoma [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr LB-A12.

Use and Effectiveness of Neoadjuvant Chemotherapy for Treatment of Ovarian Cancer

Purpose In 2010, a randomized clinical trial demonstrated noninferior survival for patients with advanced ovarian cancer who were treated with neoadjuvant chemotherapy (NACT) compared with primary cytoreductive surgery (PCS). We examined the use and effectiveness of NACT in clinical practice. Patients and Methods A multi-institutional observational study of 1,538 women with stages IIIC to IV ovarian cancer who were treated at six National Cancer Institute-designated cancer centers. We examined NACT use in patients who were diagnosed between 2003 and 2012 (N = 1,538) and compared overall survival (OS), morbidity, and postoperative residual disease in a propensity-score matched sample of patients (N = 594). Results NACT use increased from 16% during 2003 to 2010 to 34% during 2011 to 2012 in stage IIIC disease ( P_trend < .001), and from 41% to 62% in stage IV disease ( P_trend < .001). Adoption of NACT varied by institution, from 8% to 30% for stage IIIC disease (P < .001) and from 27% to 61% ( P = .007) for stage IV disease during this time period. In the matched sample, NACT was associated with shorter OS in stage IIIC disease (median OS: 33 v 43 months; hazard ratio [HR], 1.40; 95% CI, 1.11 to 1.77) compared with PCS, but not stage IV disease (median OS: 31 v 36 months; HR, 1.16; 95% CI, 0.89 to 1.52). Patients with stages IIIC and IV disease who received NACT were less likely to have ≥ 1 cm postoperative residual disease, an intensive care unit admission, or a rehospitalization (all P ≤ .04) compared with those who received PCS treatment. However, among women with stage IIIC disease who achieved microscopic or ≤ 1 cm postoperative residual disease, NACT was associated with decreased OS (HR, 1.49; 95% CI, 1.01 to 2.18; P = .04). Conclusion Use of NACT increased significantly between 2003 and 2012. In this observational study, PCS was associated with increased survival in stage IIIC, but not stage IV disease. Future studies should prospectively consider the efficacy of NACT by extent of residual disease in unselected patients.

Antitumor activity and safety of the PARP inhibitor rucaparib in patients with high-grade ovarian carcinoma and a germline or somatic BRCA1 or BRCA2 mutation: Integrated analysis of data from Study 10 and ARIEL2

OBJECTIVE

An integrated analysis was undertaken to characterize the antitumor activity and safety profile of the oral poly(ADP-ribose) polymerase inhibitor rucaparib in patients with relapsed high-grade ovarian carcinoma (HGOC).

METHODS

Eligible patients from Study 10 (NCT01482715) and ARIEL2 (NCT01891344) who received a starting dose of oral rucaparib 600mg twice daily (BID) with or without food were included in these analyses. The integrated efficacy population included patients with HGOC and a deleterious germline or somatic BRCA1 or BRCA2 (BRCA1/2) mutation who received at least two prior chemotherapies and were sensitive, resistant, or refractory to platinum-based chemotherapy. The primary endpoint was investigator-assessed confirmed objective response rate (ORR). Secondary endpoints included duration of response (DOR) and progression-free survival (PFS). The integrated safety population included patients with HGOC who received at least one dose of rucaparib 600mg BID, irrespective of BRCA1/2 mutation status and prior treatments.

RESULTS

In the efficacy population (n=106), ORR was 53.8% (95% confidence interval [CI], 43.8-63.5); 8.5% and 45.3% of patients achieved complete and partial responses, respectively. Median DOR was 9.2months (95% CI, 6.6-11.6). In the safety population (n=377), the most frequent treatment-emergent adverse events (AEs) were nausea, asthenia/fatigue, vomiting, and anemia/hemoglobin decreased. The most common grade ≥3 treatment-emergent AE was anemia/hemoglobin decreased. Treatment-emergent AEs led to treatment interruption, dose reduction, and treatment discontinuation in 58.6%, 45.9%, and 9.8% of patients, respectively. No treatment-related deaths occurred.

CONCLUSIONS

Rucaparib has antitumor activity in advanced BRCA1/2-mutated HGOC and a manageable safety profile.

Rucaparib maintenance treatment for recurrent ovarian carcinoma after response to platinum therapy (ARIEL3): a randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND

Rucaparib, a poly(ADP-ribose) polymerase inhibitor, has anticancer activity in recurrent ovarian carcinoma harbouring a BRCA mutation or high percentage of genome-wide loss of heterozygosity. In this trial we assessed rucaparib versus placebo after response to second-line or later platinum-based chemotherapy in patients with high-grade, recurrent, platinum-sensitive ovarian carcinoma.

METHODS

In this randomised, double-blind, placebo-controlled, phase 3 trial, we recruited patients from 87 hospitals and cancer centres across 11 countries. Eligible patients were aged 18 years or older, had a platinum-sensitive, high-grade serous or endometrioid ovarian, primary peritoneal, or fallopian tube carcinoma, had received at least two previous platinum-based chemotherapy regimens, had achieved complete or partial response to their last platinum-based regimen, had a cancer antigen 125 concentration of less than the upper limit of normal, had a performance status of 0-1, and had adequate organ function. Patients were ineligible if they had symptomatic or untreated central nervous system metastases, had received anticancer therapy 14 days or fewer before starting the study, or had received previous treatment with a poly(ADP-ribose) polymerase inhibitor. We randomly allocated patients 2:1 to receive oral rucaparib 600 mg twice daily or placebo in 28 day cycles using a computer-generated sequence (block size of six, stratified by homologous recombination repair gene mutation status, progression-free interval after the penultimate platinum-based regimen, and best response to the most recent platinum-based regimen). Patients, investigators, site staff, assessors, and the funder were masked to assignments. The primary outcome was investigator-assessed progression-free survival evaluated with use of an ordered step-down procedure for three nested cohorts: patients with BRCA mutations (carcinoma associated with deleterious germline or somatic BRCA mutations), patients with homologous recombination deficiencies (BRCA mutant or BRCA wild-type and high loss of heterozygosity), and the intention-to-treat population, assessed at screening and every 12 weeks thereafter. This trial is registered with ClinicalTrials.gov, number NCT01968213; enrolment is complete.

FINDINGS

Between April 7, 2014, and July 19, 2016, we randomly allocated 564 patients: 375 (66%) to rucaparib and 189 (34%) to placebo. Median progression-free survival in patients with a BRCA-mutant carcinoma was 16·6 months (95% CI 13·4-22·9; 130 [35%] patients) in the rucaparib group versus 5·4 months (3·4-6·7; 66 [35%] patients) in the placebo group (hazard ratio 0·23 [95% CI 0·16-0·34]; p<0·0001). In patients with a homologous recombination deficient carcinoma (236 [63%] vs 118 [62%]), it was 13·6 months (10·9-16·2) versus 5·4 months (5·1-5·6; 0·32 [0·24-0·42]; p<0·0001). In the intention-to-treat population, it was 10·8 months (8·3-11·4) versus 5·4 months (5·3-5·5; 0·36 [0·30-0·45]; p<0·0001). Treatment-emergent adverse events of grade 3 or higher in the safety population (372 [99%] patients in the rucaparib group vs 189 [100%] in the placebo group) were reported in 209 (56%) patients in the rucaparib group versus 28 (15%) in the placebo group, the most common of which were anaemia or decreased haemoglobin concentration (70 [19%] vs one [1%]) and increased alanine or aspartate aminotransferase concentration (39 [10%] vs none).

INTERPRETATION

Across all primary analysis groups, rucaparib significantly improved progression-free survival in patients with platinum-sensitive ovarian cancer who had achieved a response to platinum-based chemotherapy. ARIEL3 provides further evidence that use of a poly(ADP-ribose) polymerase inhibitor in the maintenance treatment setting versus placebo could be considered a new standard of care for women with platinum-sensitive ovarian cancer following a complete or partial response to second-line or later platinum-based chemotherapy.

FUNDING

Clovis Oncology.

Secondary Somatic Mutations Restoring RAD51C and RAD51D Associated with Acquired Resistance to the PARP Inhibitor Rucaparib in High-Grade Ovarian Carcinoma

High-grade epithelial ovarian carcinomas containing mutated BRCA1 or BRCA2 (BRCA1/2) homologous recombination (HR) genes are sensitive to platinum-based chemotherapy and PARP inhibitors (PARPi), while restoration of HR function due to secondary mutations in BRCA1/2 has been recognized as an important resistance mechanism. We sequenced core HR pathway genes in 12 pairs of pretreatment and postprogression tumor biopsy samples collected from patients in ARIEL2 Part 1, a phase II study of the PARPi rucaparib as treatment for platinum-sensitive, relapsed ovarian carcinoma. In 6 of 12 pretreatment biopsies, a truncation mutation in BRCA1, RAD51C, or RAD51D was identified. In five of six paired postprogression biopsies, one or more secondary mutations restored the open reading frame. Four distinct secondary mutations and spatial heterogeneity were observed for RAD51CIn vitro complementation assays and a patient-derived xenograft, as well as predictive molecular modeling, confirmed that resistance to rucaparib was associated with secondary mutations.Significance: Analyses of primary and secondary mutations in RAD51C and RAD51D provide evidence for these primary mutations in conferring PARPi sensitivity and secondary mutations as a mechanism of acquired PARPi resistance. PARPi resistance due to secondary mutations underpins the need for early delivery of PARPi therapy and for combination strategies. Cancer Discov; 7(9); 984-98. ©2017 AACR.See related commentary by Domchek, p. 937See related article by Quigley et al., p. 999See related article by Goodall et al., p. 1006This article is highlighted in the In This Issue feature, p. 920.

Epigenetic silencing of MLH1 in endometrial cancers is associated with larger tumor volume, increased rate of lymph node positivity and reduced recurrence-free survival

OBJECTIVES

To determine the relationship between mismatch repair (MMR) classification and clinicopathologic features including tumor volume, and explore outcomes by MMR class in a contemporary cohort.

METHODS

Single institution cohort evaluating MMR classification for endometrial cancers (EC). MMR immunohistochemistry (IHC)±microsatellite instability (MSI) testing and reflex MLH1 methylation testing was performed. Tumors with MMR abnormalities by IHC or MSI and MLH1 methylation were classified as epigenetic MMR deficiency while those without MLH1 methylation were classified as probable MMR mutations. Clinicopathologic characteristics were analyzed.

RESULTS

466 endometrial cancers were classified; 75% as MMR proficient, 20% epigenetic MMR defects, and 5% as probable MMR mutations. Epigenetic MMR defects were associated with advanced stage, higher grade, presence of lymphovascular space invasion, and older age. MMR class was significantly associated with tumor volume, an association not previously reported. The epigenetic MMR defect tumors median volume was 10,220mm³ compared to 3321mm³ and 2,846mm³, for MMR proficient and probable MMR mutations respectively (P<0.0001). Higher tumor volume was associated with lymph node involvement. Endometrioid EC cases with epigenetic MMR defects had significantly reduced recurrence-free survival (RFS). Among advanced stage (III/IV) endometrioid EC the epigenetic MMR defect group was more likely to recur compared to the MMR proficient group (47.7% vs 3.4%) despite receiving similar adjuvant therapy. In contrast, there was no difference in the number of early stage recurrences for the different MMR classes.

CONCLUSIONS

MMR testing that includes MLH1 methylation analysis defines a subset of tumors that have worse prognostic features and reduced RFS.

Abstract AP28: BRCA1 and RAD51C Promoter Hypermethylation Confer Sensitivity to PARP Inhibitors in Patients with Platinum Sensitive Ovarian Carcinoma

Germline and somatic mutations in BRCA1 and BRCA2 (BRCA) confer PARP inhibitor sensitivity. Promoter hypermethylation is an alternate mechanism of gene down-regulation, and BRCA1 promoter methylation is relatively common in sporadic ovarian cancer. The clinical significance of BRCA1 methylation is less clear than for mutations, as the Cancer Genome Atlas (TCGA) and others have failed to show improved survival in ovarian carcinomas with BRCA1 methylation. No one has previously tested whether BRCA1 methylation confers in vivo sensitivity to PARP inhibitors in patients with ovarian cancer. ARIEL2 is a phase 2 study of the PARP inhibitor rucaparib in patients with recurrent platinum sensitive high-grade ovarian, peritoneal or fallopian tube carcinoma. At enrollment, ARIEL2 required pre-treatment tumor biopsies with the goal of developing tissue predictors of PARP inhibitor sensitivity other than BRCA mutations. The number of women with known germline mutations was capped at 15 patients in order to predominantly enroll BRCA wildtype cases. As presented at ASCO 2016, in cases with no BRCA mutations, a high fraction of genomic loss of heterozygosity (LOH) significantly predicted a better progression-free survival (the primary endpoint), longer duration of response, and a higher fraction of responders compared to cases with low LOH. We assessed BRCA1 and RAD51C promoter hypermethylation using methylation-sensitive polymerase chain reaction in paired archival and pre-treatment biopsies from patients on ARIEL2. Of 165 cases for which methylation analyses were completed, 21 (12.7%) were methylated at the BRCA1 promoter and four (2.4%) at the RAD51C promoter. Methylation of BRCA1 and RAD51C was mutually exclusive with mutation in BRCA or other homologous recombination genes. All four cases with RAD51C methylation and 15/19 (78.9%) with BRCA1 methylation were associated with high LOH. In 90 paired samples archival and pre-treatment tissues, RAD51C methylation was 100% concordant and BRCA1 methylation was highly concordant (p&lt;0·001). For 13 cases with BRCA1 methylation in the archival specimen, 4 (30·8%) were unmethylated in the paired pretreatment tumor, but for 77 unmethylated archival specimens, gain of methylation in the pretreatment biopsy was observed just once. Confirmed RECIST responses were seen in 52.4% (11/21) BRCA1 methylated and 75.0% (3/4) RAD51C methylated cases. In conclusion, BRCA1 and RAD51C methylation in ovarian carcinomas correlates with a high response rate to PARP inhibitors. If methylation was to be used as a predictor of PARP inhibitor sensitivity, it would need to be assessed in a pre-treatment (not archival) specimen. The loss of BRCA1 methylation in recurrent ovarian carcinoma, which was common even in these platinum sensitive cases, could explain why BRCA1 methylation is associated with similar survival to methylated cases, despite initial improved therapeutic sensitivity.

Citation Format: Elizabeth Swisher, Maria Harrell, Kevin K. Lin, Clare Scott, Sandra Goble, Amit Oza, Robert L. Coleman, Gottfried Konecny, Anna V. Tinker, David M. O'Malley, Rebecca Kristeleit, Ling Ma, James Brenton, Katherine Bell-McGuinn, Ana Oaknin, Alexandra Leary, Elaina Mann, Heidi Giordano, Mitch Rapon, Iain McNeish, Scott H. Kaufmann. BRCA1 and RAD51C Promoter Hypermethylation Confer Sensitivity to PARP Inhibitors in Patients with Platinum Sensitive Ovarian Carcinoma [abstract]. In: Proceedings of the 11th Biennial Ovarian Cancer Research Symposium; Sep 12-13, 2016; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(11 Suppl):Abstract nr AP28.

Abstract AP27: FEASIBILITY OF MONITORING RESPONSE TO THE PARP INHIBITOR RUCAPARIB WITH TARGETED DEEP SEQUENCING OF CIRCULATING TUMOR DNA (CTDNA) IN WOMEN WITH HIGH GRADE OVARIAN CARCINOMA ON THE ARIEL2 TRIAL

BACKGROUND: TP53 mutations are present in &gt;97% cases of high-grade serous ovarian cancer (HGSOC). Detection of TP53 mutations in ctDNA extracted from plasma has the potential to monitor disease course and treatment response. We have developed targeted amplicon deep sequencing (TADS) to detect low frequency mutations throughout the TP53 gene in ctDNA. Rucaparib is a PARP inhibitor in development for treatment of tumors with HR pathway deficiency. We used TADS to assess TP53 mutant allele fraction (MAF) in ctDNA from patients in ARIEL2, a phase 2 study of rucaparib for treatment of relapsed high-grade ovarian cancer (NCT01891344).

MATERIAL AND METHODS: Plasma samples (n=65) from 18 patients were collected during screening, on day 1 of each cycle, and at the end of rucaparib treatment. DNA extracted from plasma underwent TADS of TP53 (median depth 6916×). FFPE tumor specimens were profiled using an NGS-based assay with a targeted gene panel including TP53. Investigator-assessed clinical response rates were evaluated by RECIST v1.1 and GCIG CA-125 criteria.

RESULTS: Concordant TP53 mutations were detected in tumor and ctDNA from plasma for all 18 patients. Median TP53 MAF at screening and cycle 1 day 1 was 5.1% (interquartile range: 1.1–17.5, n=16) and 3.8% (IQR: 0.68–10.3, n=16), respectively. Fourteen patients were evaluable for response measured by quantification of TP53 MAF between cycle 1 and 2 (missing sample: n=2; TP53 MAF &lt;0.5%; n=2). 7/9 patients with &gt;50% reduction of TP53 MAF in ctDNA at cycle 2 achieved a RECIST confirmed PR (see Table); this included 5/6 patients with either a germline or somatic mutation in BRCA1/BRCA2. No patients with &lt;50% reduction at cycle 2 (n=5) achieved a RECIST response.

CONCLUSIONS: Noninvasive detection of TP53 mutations by TADS is feasible, using plasma samples collected from women with relapsed platinum-sensitive high-grade ovarian cancer participating in an international multicenter trial. Circulating tumor DNA is a promising biomarker for monitoring response to the PARP inhibitor rucaparib. We are now testing the pre-specified hypothesis that a &gt;50% reduction in TP53 MAF between baseline and cycle 2 is predictive of response to rucaparib using 560 plasma samples from 139 ARIEL2 subjects. Updated results will be presented at the meeting.

Citation Format: Anna Piskorz, Kevin K. Lin, James Morris, Elaina Mann, Amit Oza, Robert L. Coleman, David M. O'Malley, Michael Friedlander, Janiel M. Cragun, Ling Ma, Heidi Giordano, Nitzan Rosenfeld, Mitch Raponi, Iain A. McNeish, Elizabeth Swisher, James D. Brenton. FEASIBILITY OF MONITORING RESPONSE TO THE PARP INHIBITOR RUCAPARIB WITH TARGETED DEEP SEQUENCING OF CIRCULATING TUMOR DNA (CTDNA) IN WOMEN WITH HIGH GRADE OVARIAN CARCINOMA ON THE ARIEL2 TRIAL [abstract]. In: Proceedings of the 11th Biennial Ovarian Cancer Research Symposium; Sep 12-13, 2016; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(11 Suppl):Abstract nr AP27.

Mirvetuximab soravtansine (IMGN853), a folate receptor alpha (FRα)-targeting antibody-drug conjugate (ADC), in platinum-resistant epithelial ovarian cancer (EOC) patients (pts): Activity and safety analyses in phase I pooled expansion cohorts

5547

Background: The early clinical evaluation of mirvetuximab soravtansine (IMGN853), an ADC that comprises a FRα-binding antibody linked to the tubulin-disrupting maytansinoid DM4, has revealed encouraging signs of activity in pts with ovarian cancer. A pooled analysis of safety and efficacy was performed including individuals with platinum-resistant EOC, enrolled across three expansion cohorts of an ongoing phase I trial (NCT01609556), who met the eligibility criteria for the pivotal phase III study of IMGN853 (FORWARD I; NCT02631876). Methods: Pts were administered IMGN853 intravenously once every 3 weeks at 6 mg/kg using adjusted ideal body weight dosing. Responses were assessed according to RECIST 1.1 and adverse events (AEs) evaluated by CTCAE v4.0. Results: A total of 37 EOC pts treated as part of the three phase I expansion cohorts (pooled population; n = 113) met the FORWARD I enrollment criteria of moderate to high tumor FRα levels (≥ 50% of cells with ≥ 2+ FRα expression) and 1-3 prior lines of therapy. In this group of pts with platinum-resistant disease, confirmed objective tumor responses were observed in 17 individuals (1 complete response [CR] and 16 partial responses [PR]) for an overall response rate (ORR) of 46% (95% CI, 29.5, 63.1) and a median PFS of 6.7 months (95% CI, 4.1, 9.0). The safety profile of the pooled population was consistent with that previously reported (ASCO Annual Meeting, 2016) with the most common AEs being diarrhea, fatigue, nausea, and blurred vision; these were low grade and readily managed. Conclusions: IMGN853 continues to be characterized by favorable tolerability and encouraging activity in pts with platinum-resistant EOC. In particular, both the ORR (46%) and PFS (6.7 months) achieved in this group of pts are superior to outcomes typically seen with established single-agent chemotherapy within the setting of primary platinum resistance. Overall, these analyses provide continued, robust support for the patient eligibility strategy employed in the phase III evaluation of IMGN853. Clinical trial information: NCT01609556.

A randomized phase III trial of cisplatin and tumor volume directed irradiation followed by carboplatin and paclitaxel vs. carboplatin and paclitaxel for optimally debulked, advanced endometrial carcinoma

5505

Background: Patients with stage III/IVA uterine cancer (UC) carry high risk of systemic and local recurrence. Chemotherapy was shown to reduce systemic recurrence, however the risk of local failure remains high. Methods: The primary endpoint of this open label, randomized phase III trial was to determine if treatment with cisplatin and volume-directed radiation followed by carboplatin and paclitaxel for 4 cycles (C-RT, experimental arm) reduces the rate of recurrence or death (i.e., increases recurrence-free survival, RFS) when compared to carboplatin and paclitaxel for 6 cycles (CT, control arm) in patients with stages III-IVA (<2 cm residual disease) or FIGO 2009 stage I/II serous or clear cell UC and positive cytology. Secondary objectives were assessment of overall survival (OS), acute and late toxicities, and quality of life. A 28.5% reduction in the rate of recurrence or death was considered significant. Treatment randomization and analysis were stratified by gross residual tumor and age. Results: Between 6/2009 and 7/2014, 813 patients were enrolled and randomized (407 C-RT and 406-CT). Of those, 733 were eligible (344 C-RT and 360 CT), and 680 received the trial intervention (333 C-RT and 347 CT). Median follow up is 47 months. Patients characteristics were balanced between arms. There were 201 (58%) > grd 3 toxicity events in the C-RT arm and 227 (63%) in the CT arm. The most common > grd 3 events were myelosupression (40% vs. 52%), gastrointestinal (13% vs. 4%), metabolic (15% vs. 19%), neurological (7% vs. 6%), infectious (4% vs. 5%). Treatment hazard ratio for RFS was 0.9 (C-RT vs. CT; CI 0.74 to 1.10). C-RT reduced the incidence of vaginal (3% vs. 7%, HR = 0.36, CI 0.16 to 0.82), pelvic and paraaortic recurrences (10% vs. 21%, HR=0.43, CI 02.8 to 0.66) compared to CT, but distant recurrences were more common with C-RT vs. CT (28% vs. 21%, HR 1.36, CI 1 to 1.86). The analysis is premature for OS comparison. Conclusions: Although C-RT reduced the rate of local recurrence compared to CT; the combined modality regimen did not increase RFS in optimally debulked, stage III/IVA UC. Clinical trial information: NCT00942357.

Safety findings from FORWARD II: A Phase 1b study evaluating the folate receptor alpha (FRα)-targeting antibody-drug conjugate (ADC) mirvetuximab soravtansine (IMGN853) in combination with bevacizumab, carboplatin, pegylated liposomal doxorubicin (PLD), or pembrolizumab in patients (pts) with ovarian cancer

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Background: FORWARD II is a phase 1b study of the FRα-targeting ADC, mirvetuximab soravtansine (IMGN853), in combination with bevacizumab (BEV), carboplatin, PLD, or pembrolizumab in adults with FRα-positive EOC, primary peritoneal, or fallopian tube tumors (NCT02606305). Methods: The escalation stage of this trial evaluated the safety and tolerability of IMGN853 as part of 4 combination regimens: IMGN853 + BEV; + carboplatin; + PLD; and + pembrolizumab. IMGN853 was administered in combination on Day 1 of a 21 (BEV or carboplatin) or 28-day cycle (PLD). Pembrolizumab escalation is continuing. The starting dose of IMGN853 was 5 mg/kg (adjusted ideal body weight, AIBW), one level lower than the recommended single agent phase 2 dose (RP2D; 6 mg/kg AIBW) defined in a first-in-human study (NCT01609556). Adverse events (AEs) were evaluated by CTCAE v4.0. Results: 46 pts enrolled in the first 3 cohorts. IMGN853 was escalated from 5 to 6 mg/kg. Carboplatin and PLD dosing were escalated from AUC4 to AUC5 and 30 to 40 mg/m2, respectively; BEV dosing remained constant at 15 mg/kg. Diarrhea, nausea, and fatigue were common across cohorts (all grades; 33-57%) and mostly low grade (i.e. ≤ 2), consistent with the IMGN853 safety profile from the earlier phase I monotherapy study. AEs of interest related to the combination agents were seen in each arm. For example, grade 1/2 proteinuria (36%) and grade 3 hypertension (21%) were only observed in the BEV combination. Thrombocytopenia (44%) and neutropenia (39%), grades 1-3, occurred most frequently in the carboplatin arm. Grade 3 anemia and vomiting (each 14%), as well as low grade (≤ 2) constipation (43%), were seen in the PLD cohort. Conclusions: The RP2D dose of IMGN853 was readily combined with the highest doses (as per protocol) of BEV, carboplatin, and PLD. The AE profiles for these combinations were manageable and as expected based on known profiles of each agent; importantly, no new safety signals were identified. Updated data from all 4 combination regimens will be presented. Clinical trial information: NCT02606305.

Phase 1 dose-escalation study of mirvetuximab soravtansine (IMGN853), a folate receptor α-targeting antibody-drug conjugate, in patients with solid tumors

BACKGROUND

Mirvetuximab soravtansine (IMGN853) is an antibody-drug conjugate that selectively targets folate receptor α (FRα). In this phase 1 dose-escalation study, the authors investigated IMGN853 in patients with FRα-positive solid tumors.

METHODS

Patients received IMGN853 on day 1 of a 21-day cycle (once every 3 weeks dosing), with cycles repeated until patients experienced dose-limiting toxicity or progression. Dose escalation commenced in single-patient cohorts for the first 4 planned dose levels and then followed a standard 3 + 3 scheme. The primary objectives were to determine the maximum tolerated dose and the recommended phase 2 dose. Secondary objectives were to determine safety and tolerability, to characterize the pharmacokinetic profile, and to describe preliminary clinical activity.

RESULTS

In total, 44 patients received treatment at doses escalating from 0.15 to 7.0 mg/kg. No meaningful drug accumulation was observed with the dosing regimen of once every 3 weeks. The most common treatment-related adverse events were fatigue, blurred vision, and diarrhea, the majority of which were grade 1 or 2. The dose-limiting toxicities observed were grade 3 hypophosphatemia (5.0 mg/kg) and grade 3 punctate keratitis (7.0 mg/kg). Two patients, both of whom were individuals with epithelial ovarian cancer, achieved confirmed tumor responses according to Response Evaluation Criteria in Solid Tumors 1.1, and each was a partial response.

CONCLUSIONS

IMGN853 demonstrated a manageable safety profile and encouraging preliminary clinical activity, particularly in patients with ovarian cancer. The results establish a recommended phase 2 dosing of 6.0 mg/kg (based on adjusted ideal body weight) once every 3 weeks. Cancer 2017. © 2017 American Cancer Society. Cancer 2017;123:3080-7. © 2017 American Cancer Society.

Bevacizumab and paclitaxel-carboplatin chemotherapy and secondary cytoreduction in recurrent, platinum-sensitive ovarian cancer (NRG Oncology/Gynecologic Oncology Group study GOG-0213): a multicentre, open-label, randomised, phase 3 trial

BACKGROUND

Platinum-based chemotherapy doublets are a standard of care for women with ovarian cancer recurring 6 months after completion of initial therapy. In this study, we aimed to explore the roles of secondary surgical cytoreduction and bevacizumab in this population, and report the results of the bevacizumab component here.

METHODS

The multicentre, open-label, randomised phase 3 GOG-0213 trial was done in 67 predominantly academic centres in the USA (65 centres), Japan (one centre), and South Korea (one centre). Eligible patients were adult women (aged ≥18 years) with recurrent measurable or evaluable epithelial ovarian, primary peritoneal, or fallopian tube cancer, and a clinical complete response to primary platinum-based chemotherapy, who had been disease-free for at least 6 months following last infused cycle of platinum. Patients were randomly assigned (1:1) to standard chemotherapy (six 3-weekly cycles of paclitaxel [175 mg/m² of body surface area] and carboplatin [area under the curve 5]) or the same chemotherapy regimen plus bevacizumab (15 mg/kg of bodyweight) every 3 weeks and continued as maintenance every 3 weeks until disease progression or unacceptable toxicity. Individuals who participated in both the bevacizumab objective and surgical objective (which is ongoing) were randomly assigned (1:1:1:1) to receive either of these two chemotherapy regimens with or without prior secondary cytoreductive surgery. Randomisation for the bevacizumab objective was stratified by treatment-free interval and participation in the surgical objective. The primary endpoint was overall survival, analysed by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00565851.

FINDINGS

Between Dec 10, 2007, and Aug 26, 2011, 674 women were enrolled and randomly assigned to standard chemotherapy (n=337) or chemotherapy plus bevacizumab (n=377). Median follow-up at the end of the trial on Nov 5, 2014, was 49·6 months in each treatment group (IQR 41·5-62·2 for chemotherapy plus bevacizumab; IQR 40·8-59·3 for chemotherapy), at which point 415 patients had died (214 in the chemotherapy group and 201 in the chemotherapy plus bevacizumab group). Based on pretreatment stratification data, median overall survival in the chemotherapy plus bevacizumab group was 42·2 months (95% CI 37·7-46·2) versus 37·3 months (32·6-39·7) in the chemotherapy group (hazard ratio [HR] 0·829; 95% CI 0·683-1·005; p=0·056). We identified incorrect treatment-free interval stratification data for 45 (7%) patients (equally balanced between treatment groups); a sensitivity analysis of overall survival based on the audited treatment-free interval stratification data gave an adjusted HR of 0·823 (95% CI 0·680-0·996; p=0·0447). In the safety population (all patients who initiated treatment), 317 (96%) of 325 patients in the chemotherapy plus bevacizumab group had at least one grade 3 or worse adverse event compared with 282 (86%) of 332 in the chemotherapy group; the most frequently reported of these in the chemotherapy plus bevacizumab group compared with the chemotherapy group were hypertension (39 [12%] vs two [1%]), fatigue (27 [8%] vs eight [2%]), and proteinuria (27 [8%] vs none). Two (1%) treatment-related deaths occurred in the chemotherapy group (infection [n=1] and myelodysplastic syndrome [n=1]) compared with nine (3%) in the chemotherapy plus bevacizumab group (infection [n=1], febrile neutropenia [n=1], myelodysplastic syndrome [n=1], secondary malignancy [n=1]; deaths not classified with CTCAE terms: disease progression [n=3], sudden death [n=1], and not specified [n=1]).

INTERPRETATION

The addition of bevacizumab to standard chemotherapy, followed by maintenance therapy until progression, improved the median overall survival in patients with platinum-sensitive recurrent ovarian cancer. Although the intention-to-treat analysis for overall survival was not significant, our sensitivity analysis based on corrected treatment-free interval stratification indicates that this strategy might be an important addition to the therapeutic armamentarium in these patients.

FUNDING

National Cancer Institute and Genentech.

Outpatient desensitization in selected patients with platinum hypersensitivity reactions

Platinum-based chemotherapies are a standard treatment for both initial and recurrent gynecologic cancers. Given this widespread use, it is important to be aware of the features of platinum hypersensitivity reactions and the subsequent treatment of these reactions. There is also increasing interest in the development of desensitization protocols to allow patients with a history of platinum hypersensitivity to receive further platinum based therapy. In this review, we describe the management of platinum hypersensitivity reactions and the desensitization protocols utilized at our institution. We also describe the clinical categorizations utilized to triage patients to appropriate desensitization protocols.