Platinum-resistant Advanced Ovarian Cancer Research Articles

Abstract LB_A13: Phase 1 dose expansion results of CYT-0851, a monocarboxylate transporter (MCT) inhibitor, in combination with capecitabine (cape) in platinum-resistant ovarian cancer

Abstract Background: The MCT inhibitor CYT-0851 potently inhibits MCT1, has activity against MCT4, and blocks lactate transport resulting in cell death in glycolytic cancer cells. In an in vitro CRISPR screen, thymidylate synthetase was a significant hit in 2 resistant cell models, sensitizing them to CYT-0851. Follow-up in vitro combination studies showed that CYT-0851 synergized with 5-FU to inhibit cancer cell growth. Monotherapy clinical activity of CYT-0851 has been reported previously in lymphoma and solid tumors. In the phase 1 dose escalation trial of CYT-0851 plus cape, 400 mg was identified as the recommended phase 2 dose. In three phase 2 trials, cape had a RECIST response rate of 5-8% in ovarian cancer. Methods: An expansion cohort of 10 patients (pts) with platinum resistant advanced ovarian cancer were treated with CYT-0851, 400 mg QD in combination with cape, 1000 mg/m2 PO BID x 14 days every 21 days and were evaluable. One additional pt treated at the 300 mg dose level was evaluable and added to the analysis. The primary objective was safety, and secondary objectives were pharmacokinetics and preliminary anti-tumor activity by RECIST. Results: As of Aug 21, 2023, 11 pts were treated and evaluable, 9 white, 1 African American black, and 1 American Indian or Alaskan native, with a median age of 64 (range 52-76). Median prior therapies were 6 (range 2-14). All but one had 3 or more prior therapies. Median CYT-0851 dose compliance with continuous daily dosing was 99% (range 91– 100%). There were no treatment discontinuations or CYT-0851 dose reductions for treatment related adverse events. 7 pts (64%) experienced a treatment-related adverse event, all were Grade 1-2. There were no grade 3+ treatment related adverse events. The most common related AEs were fatigue reported in 5 pts (46%), and decreased appetite, diarrhea, nausea, palmar-plantar erythrodysaesthesia syndrome and vomiting, each reported in 2 patients (18%). Exposure of CYT-0851 in combination with capecitabine exhibits dose proportional behavior and was similar between combination therapy and monotherapy. One pt had a confirmed PR with progression on day 294, and 2 additional pts achieved a PR that has not been confirmed yet, with treatment ongoing on day 113 and 41. 7 pts had SD, and one patient PD as best response. The disease control rate was 91%. 5 Pts discontinued for progressive disease with a median of 133 days of treatment (range 43-300), and 2 withdrew consent on days 131-134. 4 patients continue therapy on days 42,47,106, and 113. Median PFS was 170 days (95% CI 79-NA). Conclusions: The oral outpatient combination of CYT-0851 and cape has demonstrated an acceptable safety and tolerability profile without any unanticipated toxicities at clinically active doses. The disease control rate of 91% and unconfirmed response rate of 27% in refractory platinum resistant ovarian cancer is promising and warrants further exploration. Furthermore, this regimen should be evaluated in other tumor types commonly treated with 5-FU, including breast and colorectal cancer. Citation Format: Elizabeth Swisher, Gerald Steven Falchook, Pamela N. Munster, Nina Beri, Kathleen N. Moore, Timothy A. Yap, David R. Spigel, Susan Doleman, William D. Bradley, Thomas J. O'Shea, Markus F. Renschler, Ryan C. Lynch. Phase 1 dose expansion results of CYT-0851, a monocarboxylate transporter (MCT) inhibitor, in combination with capecitabine (cape) in platinum-resistant ovarian cancer [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr LB_A13.

Uplift (ENGOT-ov67): A pivotal cohort to evaluate XMT-1536 (upifitamab rilsodotin), a NaPi2b-directed antibody drug conjugate for platinum-resistant ovarian cancer.

TPS5607 Background: XMT-1536 (upifitamab rilsodotin), is a first-in-class Dolaflexin ADC targeting NaPi2b, a sodium-dependent phosphate transport protein, broadly expressed in solid tumors such as serous epithelial ovarian cancer (OC) and non-small cell lung adenocarcinoma. XMT-1536 uses the Dolaflexin platform to deliver approximately 10 DolaLock auristatin payload molecules per antibody and is being evaluated in a Phase I study (NCT03319628). Observation of preliminary antitumor activity was reported in the ovarian cancer expansion cohort, including in patients previously treated with bevacizumab and PARPi (Tolcher et al, ASCO 2019; Richardson et al, ASCO 2019; Hamilton et al, ESMO 2020). Updated data on the OC cohort included 31 patients with higher NaPi2b expression as of December 2020 (Mersana Therapeutics, 2021). In these patients, the ORR was 32% and the DCR was 74%. Complete responses were observed in 2 patients with platinum-resistant ovarian cancer, both of whom had received prior treatment with bevacizumab and PARP inhibitors. Platinum resistant ovarian cancer remains a serious unmet medical need as treatment options are limited and response rates to these treatments are low. Based on the favorable safety and efficacy profile of XMT-1536, UPLIFT was designed as a Phase 2 single-arm registrational cohort of patients with platinum resistant ovarian cancer as part of the ongoing Phase I FIH dose escalation and expansion study to accelerate development and provide a streamlined pathway to regulatory review. Methods: The UPLIFT cohort is enrolling patients with platinum resistant high grade serous ovarian, fallopian tube and primary peritoneal cancer with up to 4 prior lines of therapy. The RP2D of XMT-1536 was determined to be 43 mg/m2 administered intravenously every 4 weeks (q4w) and will be the dose evaluated in the UPLIFT cohort. UPLIFT will enroll approximately 180 patients with platinum-resistant advanced ovarian cancer to obtain approximately 100 patients with higher NaPi2b expression. Prior bevacizumab is required for those patients with 1 or 2 prior lines of therapy. Tumor samples (fresh or archived) will be collected prior to enrollment for retrospective tumor tissue evaluation of NaPi2b expression. The primary objective is assessment of confirmed objective response rate to XMT-1536 as assessed by Investigator in patients with higher NaPi2b expression. Secondary endpoints include confirmed objective response rate regardless of NaPi2b expression, duration of response, and adverse events. Correlative aims include assessing blood and tissue biomarkers for association with clinical benefit. This study is being conducted in collaboration with ENGOT and GOG. Patients will be enrolled globally. Clinical trial information: NCT03319628.

Randomized phase II study of the PDGFR\u03b1 antibody olaratumab plus liposomal doxorubicin versus liposomal doxorubicin alone in patients with platinum-refractory or platinum-resistant advanced ovarian cancer

BackgroundOlaratumab is a platelet-derived growth factor receptor-α (PDGFRα)-targeting monoclonal antibody blocking PDGFRα signaling. PDGFRα expression is associated with a more aggressive phenotype and poor ovarian cancer outcomes. This randomized, open label phase II study evaluated olaratumab plus liposomal doxorubicin compared with liposomal doxorubicin alone in advanced ovarian cancer patients.MethodsPatients with platinum-refractory or platinum-resistant advanced ovarian cancer were randomized 1:1 to receive liposomal doxorubicin (40 mg/m2, intravenous infusion) administered every 4 weeks with or without olaratumab (20 mg/kg, IV infusion) every 2 weeks. Patients were stratified based on prior response to platinum therapy (refractory vs resistant). The primary efficacy endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), objective response rate, duration of response, and safety.ResultsA total of 123 patients were treated (62 olaratumab+liposomal doxorubicin; 61 liposomal doxorubicin). Median PFS was 4.2 months for olaratumab+liposomal doxorubicin and 4.0 months for liposomal doxorubicin (stratified hazard ratio [HR] = 1.043; 95% confidence interval [CI] 0.698–1.558; p = 0.837). Median OS was 16.6 months and 16.2 months in the olaratumab+liposomal doxorubicin and liposomal doxorubicin arms, respectively (HR = 1.098; 95% CI 0.71–1.71). In the platinum-refractory subgroup, median PFS was 5.5 months (95% CI 1.6–9.2) and 3.7 months (95% CI 1.9–9.2) in the olaratumab+liposomal doxorubicin (n = 15) and liposomal doxorubicin arms (n = 16), respectively (HR = 0.85; 95% CI 0.38–1.91). Overall, 59.7% (olaratumab+liposomal doxorubicin) and 65.6% (liposomal doxorubicin) of patients reported grade ≥ 3 adverse events regardless of causality. The most common treatment-emergent adverse events (all grades) regardless of causality were fatigue related (61%), nausea (57%), and constipation (52%) with olaratumab+liposomal doxorubicin and nausea (64%), fatigue related (62%), and mucositis (46%) with liposomal doxorubicin.ConclusionsThe addition of olaratumab to liposomal doxorubicin did not result in significant prolongation of PFS or OS in platinum-resistant or platinum-refractory ovarian cancer.Trial registrationClinicalTrials.gov identifier: NCT00913835; registered June 2, 2009.

Improved Survival Trends in Platinum-Resistant Patients with Advanced Ovarian, Fallopian or Peritoneal Cancer Treated with First-Line Paclitaxel/Platinum Chemotherapy: The Impact of Novel Agents

Objective: The prognosis for patients with platinum-resistant advanced ovarian cancer remains poor. The impact of approved agents on survival has not been clarified during the last decade. We studied survival trends during the last 15 years in platinum-resistant patients treated with cytoreductive surgery followed by paclitaxel/platinum chemotherapy. Methods: Patients with epithelial ovarian, fallopian or peritoneal cancer, stages III/IV and platinum-resistant disease after first-line chemotherapy with paclitaxel/platinum were included. They were grouped according to the period of chemotherapy: group A 31/3/1995–31/12/2001 (n = 56) and Group B 1/1/2002–24/12/2008 (n = 57). In order to compensate for the difference in follow-up between the 2 groups, we performed minimum follow-up (MFU) analyses by considering as cases only women who had an event within 3 years of follow-up. Patients with no events for up to 3 years were censored at that time. Results: MFU analyses showed that median overall survival (OS) was significantly longer in group B: 12.3 vs. 17.5 months (p = 0.012). This was due to a doubling of the median OS after relapse: 5.7 vs. 10.9 months (p = 0.0180). Multivariate Cox regression indicated group and histology as factors statistically significantly associated with OS. Following relapse, patients in group B were predominantly treated with liposomal doxorubicin and gemcitabine, and patients in group A were treated with platinum compounds, docetaxel and oral etoposide (p < 0.001). Conclusions: The introduction of novel agents without cross-resistance to platinum or taxanes has improved the prognosis of platinum-resistant patients.

Second-Line Treatment with Intravenous Gemcitabine and Oral Etoposide in Platinum-Resistant Advanced Ovarian Cancer Patients: Results of a Phase II Study

Objective: The outcome of advanced ovarian cancer patients has not significantly improved since the introduction of platinum. One of the major reasons for this failure is the lack of an effective second-line treatment. In this phase II trial we tested the combination of gemcitabine and etoposide in 2 different groups of patients. Group 1 consisted of patients showing disease progression or relapse within 6 months of first-line platinum-based chemotherapy. Group 2 comprised heavily pretreated patients showing progression during the last chemotherapy attempt. Methods: Thirty-four patients were enrolled. Gemcitabine was administered at a dose of 1,000 mg/m² on days 1 and 8 and etoposide was administered orally at 100 mg/day on days 8–12 for 6 courses. Results: Eighteen patients (52.9%) had an objective response and the median duration of the response was 10.3 months. Our chemotherapy regimen showed a low toxicity and good patient compliance. In 5 patients the treatment had to be delayed and in only 2 patients it was discontinued. Conclusions: The combination of gemcitabine and oral etoposide seems to be a safe and effective second-line treatment for platinum-resistant ovarian cancer patients. Additional data on larger series are warranted to better define the activity of this combination regimen.

Which symptoms are prevalent in patients with recurrent ovarian cancer?

20689 Background: Improved characterization of the symptoms of recurrent ovarian cancer pts is needed to facilitate better treatment and palliation. Methods: Single center study involving platinum-resistant advanced ovarian cancer patients. After informed consent, pts were interviewed and asked to complete the Memorial Symptom Assessment Scale [MSAS] with additional added symptom questions from the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-OV28 [EORTC QLQ-OV 28] as well as the complete Functional Assessment of Cancer Therapy for pts with ovarian cancer [FACT-O]. Pts were asked to rate the frequency from 0–4 (0=not at all, 4=very frequent), severity from 0–4 (0=not at all, 4=very severe) and distress level from 0–4 (0=not at all, 4=very severe) of each symptom. Results: Fifty pts were interviewed. The median age of the study group was 56 (range 35–77), predominately white (86%), and education beyond high school (92%). 42 pts had ECOG performance status < 1 (84%). Among symptoms with scores > 2 on each of the dimensions of frequency (F), severity (S) and distress (D): “lack of energy” (n = S28, D23, F35), “worrying” (S26, D21, F30) and “pain” (S23, D20, F29) ranked 1,2 and 3 for each of the dimensions. The top seven ranked symptoms with scores >2 on each of the dimensions were identical and in addition to “lack of energy”, “worrying” and “pain” included: “muscle aches and pain” (S23, D17, F25), “feeling bloated” (S19, D18, F20), “difficulty sleeping” (S18, D18, F24) and “feeling nervous” (S19, D17, F23). For the 18 symptoms studied: correlations between frequency and severity ranged from 0.81–0.97, correlations between frequency and distress ranged from 0.69–0.96, and correlations between distress and severity ranged from 0.71–0.92. Conclusions: Specific and not frequently assessed psychological as well as somatic symptoms were prevalent among platinum resistant ovarian cancer pts studied and these correlated with quality of life. Close correlation between severity, distress and frequency as dimensions of symptoms suggest that these may be collapsed to a single dimension for each symptom. No significant financial relationships to disclose.

A multicenter phase II study of the cryptophycin analog LY355703 in patients with platinum-resistant ovarian cancer

LY355703 is a synthetic product structurally related to the cryptophycin family isolated from the blue-green algae, which exerts a potent destabilization of microtubules during mitosis. This study was performed to determine the activity of LY355703 in patients with platinum-resistant advanced ovarian cancer and to characterize its toxicity profile. Twenty-six patients were enrolled in this study. Resistant disease was defined as a platinum-free interval of <6 months from primary treatment or rechallenge. LY355703 (1.5 mg/m(2)) was administered intravenously on days 1 and 8, every 3 weeks, infused over 2 h. From 24 patients evaluable for response, three partial responses (12.5%) and seven disease stabilizations were registered (29.2%), for an overall clinical benefit of 41.7%. Fourteen patients (58.3%) experienced a progression of the disease during treatment. Among the 25 patients evaluable for toxicity, two episodes of grade 3 anemia (8%); one, grade 3 thrombocytopenia (4%); one, grade 4 elevation of creatinine (4%); and one, grade 3 hyperbilirubinemia (4%) were reported. LY355703 has a modest activity in patients with platinum-resistant advanced ovarian cancer. Nevertheless, the considerable rate of disease stabilization in the absence of serious adverse events in this poor-prognosis study population suggests that this novel cryptophycin may deserve further investigation in this setting.

A multicenter phase II study of the cryptophycin analog LY355703 in patients with platinum-resistant ovarian cancer

LY355703 is a synthetic product structurally related to the cryptophycin family isolated from the blue-green algae, which exerts a potent destabilization of microtubules during mitosis. This study was performed to determine the activity of LY355703 in patients with platinum-resistant advanced ovarian cancer and to characterize its toxicity profile. Twenty-six patients were enrolled in this study. Resistant disease was defined as a platinum-free interval of &lt;6 months from primary treatment or rechallenge. LY355703 (1.5 mg/m2) was administered intravenously on days 1 and 8, every 3 weeks, infused over 2 h. From 24 patients evaluable for response, three partial responses (12.5%) and seven disease stabilizations were registered (29.2%), for an overall clinical benefit of 41.7%. Fourteen patients (58.3%) experienced a progression of the disease during treatment. Among the 25 patients evaluable for toxicity, two episodes of grade 3 anemia (8%); one, grade 3 thrombocytopenia (4%); one, grade 4 elevation of creatinine (4%); and one, grade 3 hyperbilirubinemia (4%) were reported. LY355703 has a modest activity in patients with platinum-resistant advanced ovarian cancer. Nevertheless, the considerable rate of disease stabilization in the absence of serious adverse events in this poor-prognosis study population suggests that this novel cryptophycin may deserve further investigation in this setting.

A multi-center phase II study of the cryptophycin analogue LY355703 in patients with platinum-resistant ovarian cancer

5097 Background: LY355703 is a synthetic product structurally related to the cryptophycin family isolated from the blue-green algae, which exerts a potent destabilization of microtubules during mitosis. This study was performed to determine the activity of LY355703 in patients with platinum-resistant advanced ovarian cancer and to characterize its toxicity profile. Methods: Twenty-six patients were registered into this study. Resistant disease was defined as a platinum-free interval <6 months from primary treatment or re-challenge. Further entry criteria were: radiological evidence of bidimensionally measurable disease as defined by the South Western Oncology Group (SWOG) criteria; age over 18 years; WHO performance status < 2; no more than one prior chemotherapy regimen, (with the exception of patients who remained platinum sensitive after second line therapy); life expectancy >12 weeks; absolute neutrophil count ≥ 1,5 x109/l; platelet count >150 x109/l; bilirubin and creatinine levels less than 1.5 times the upper limit of normality (ULN); liver enzymes (AST, ALT) <2.5 x ULN. Written informed consent was required from all eligible patients prior to enrollment into the study. LY355703 1.5 mg/m2, was administered intravenously on days 1 and 8 every three weeks, infused over two hours. Results: From 24 patients evaluable for response, 3 partial responses (12.5%) and 7 disease stabilizations lasting more than 4 months were registered (29.2%), for an overall clinical benefit of 41.7%. Fourteen patients (58.3%) experienced a progression of the disease during treatment. Among the 25 patients evaluable for toxicity 2 episodes of grade 3 anemia (8%), 1 grade 3 thrombocytopenia (4%), one grade 4 elevation of creatinine (4%) and one grade 3 hyperbilirubinemia (4%)were reported. Conclusions: LY355703 has a modest activity in patients with platinum-resistant advanced ovarian cancer. Nevertheless, the considerable rate of disease stabilization in the absence of serious adverse events in this poor-prognosis study population suggests that this novel cryptophycin may deserve further investigation in this setting. No significant financial relationships to disclose.

A Phase I Study of Paclitaxel and Epirubicin, without and with Filgrastim, for the Treatment of Platinum-Resistant Advanced Ovarian Cancer

The aim of the study was to determine the maximum tolerated dose (MTD) of epirubicin combined with a fixed dose of paclitaxel, without and with support of filgrastim, in patients with platinum resistant or refractory ovarian cancer. Paclitaxel (150 mg/m²) and epirubicin (starting dose 90 mg/m², 15 mg/m² escalation per level) were given on day 1, every 28 days for 4–6 cycles. Filgrastim (F) (5 µg/kg/die) was given in case of grade 4 leukopenia (levels without support) or from day 4 up to leukocyte count >10,000/mm³ after nadir (levels with support). Cohorts of 3 patients were enrolled at each level and further 3 patients were planned if 1 or 2 unacceptable toxic events (UTE) were registered. MTD was determined first without and then with filgrastim. Four levels were studied (90, 90+F, 105+F, 120+F) with 4, 6, 5 and 4 patients enrolled, respectively. UTE (grade 4 neutropenia) were observed in 3 patients at level 1. Thus, 90 mg/m² was the MTD for epirubicin without filgrastim. MTD of epirubicin with filgrastim was not reached at 120 mg/m². Hematological toxicity was mild. Grade 3 mucositis was reported in 1 patient. Among the 14 patients with measurable or evaluable disease, 3 objective responses were observed (1 complete and 2 partial) for an overall response rate of 21.4%. The combination of paclitaxel 150 mg/m² and epirubicin at 120 mg/m² with filgrastim is a feasible therapy. Grade 4 leukopenia is the dose limiting toxicity using epirubicin at 90 mg/m² without filgrastim.