Antitumor activity of lurbinectedin (PM01183) and doxorubicin in relapsed small-cell lung cancer: results from a phase I study.

BACKGROUND: Lurbinectedin (PM01183) has synergistic antitumor activity when combined with doxorubicin in mice with xenografted tumors. This phase I trial determined the recommended dose (RD) of doxorubicin (bolus) and PM01183 (1-h intravenous infusion) on day 1 every 3 weeks (q3wk), and obtained preliminary evidence of antitumor activity for this combination in small-cell lung cancer (SCLC). PATIENTS AND METHODS: Patients with advanced solid tumors received doxorubicin and PM01183 following a standard dose escalation design and expansion at the RD. Twenty-seven patients had relapsed SCLC: 12 with sensitive disease (platinum-free interval ≥90 days) and 15 with resistant disease (platinum-free interval <90 days). RESULTS: Doxorubicin 50 mg/m2 and PM01183 4.0 mg flat dose was the RD. In relapsed SCLC, treatment tolerance at the RD was manageable. Transient and reversible myelosuppression (including neutropenia, thrombocytopenia, and febrile neutropenia) was the main toxicity, managed with dose adjustment and colony-stimulating factors. Fatigue (79%), nausea/vomiting (58%), decreased appetite (53%), mucositis (53%), alopecia (42%), diarrhea/constipation (42%), and asymptomatic creatinine (68%) and transaminase increases (alanine aminotransferase 42%; aspartate aminotransferase 32%) were common, and mostly mild or moderate. Complete (n = 2, 8%) and partial response (n = 13, 50%) occurred in relapsed SCLC, mostly at the RD. Response rates at second line were 91.7% in sensitive disease [median progression-free survival (PFS)=5.8 months] and 33.3% in resistant disease (median PFS = 3.5 months). At third line, response rate was 20.0% (median PFS = 1.2 months), all in resistant disease. CONCLUSION: Doxorubicin 50 mg/m2 and PM01183 4.0 mg flat dose on day 1 q3wk has shown remarkable activity, mainly in second line, with manageable tolerance in relapsed SCLC, leading to further evaluation of this combination within an ongoing phase III trial.

Phase II randomized study of PM01183 versus topotecan in patients with platinum-resistant/refractory advanced ovarian cancer.

BACKGROUND: PM01183 is a new compound that blocks active transcription, produces DNA breaks and apoptosis, and affects the inflammatory microenvironment. PM01183 showed strong antitumor activity in preclinical models of cisplatin-resistant epithelial ovarian cancer. PATIENTS AND METHODS: Patients with platinum-resistant/refractory ovarian cancer were included in a two-stage, controlled, randomized (in a second stage), multicenter, phase II study. Primary endpoint was overall response rate (ORR) by RECIST and/or GCIG criteria. The exploratory first stage (n = 22) confirmed the activity of PM01183 as a single agent at 7.0 mg flat dose every 3 weeks (q3wk). The second stage (n = 59) was randomized and controlled with topotecan on days 1-5 q3wk or weekly (every 4 weeks, q4wk). RESULTS: ORR was 23% (95% CI, 13%-37%) for 52 PM01183-treated patients. Median duration of response was 4.6 months (95% CI, 2.5-6.9 months), and 23% (95% CI, 0%-51%) of responses lasted 6 months or more. Ten of the 12 confirmed responses were reported for 33 patients with platinum-resistant disease [ORR = 30% (95% CI, 16%-49%)]; for the 29 patients treated with topotecan in the second stage, no responses were found. Median PFS for all PM01183-treated patients was 4.0 months (95% CI, 2.7-5.6 months), and 5.0 months (95% CI, 2.7-6.9 months) for patients with platinum-resistant disease. Grade 3/4 neutropenia in 85% of patients; febrile neutropenia in 21% and fatigue (grade 3 in 35%) were the principal safety findings for PM01183. CONCLUSION: PM01183 is an active drug in platinum-resistant/refractory ovarian cancer and warrants further development. The highest activity was observed in platinum-resistant disease. Its safety profile indicates the dose should be adjusted to body surface area (mg/m2). TRIAL CODE: EudraCT 2011-002172-16.

Activity of trabectedin in germline BRCA1/2-mutated metastatic breast cancer: results of an international first-in-class phase II study.

BACKGROUND: Breast cancer is a heterogeneous disease defined by both germline and somatic abnormalities. In preclinical models, tumors carrying homologous recombination defects are highly sensitive to trabectedin. This phase II trial evaluated the efficacy and safety of trabectedin in BRCA1/2 germline mutation carriers with pretreated metastatic breast cancer (MBC). PATIENTS AND METHODS: Trabectedin 1.3 mg/m(2) as a 3-h i.v. infusion was administered every 3 weeks until progression or intolerance. The primary efficacy end point was the objective response rate (ORR) as per RECIST. Secondary efficacy end points comprised time-to-event end points, and changes in tumor volume and expression of tumor marker CA15.3. Safety was evaluated using the NCI-CTCAE. RESULTS: Forty BRCA1/2 germline mutation carriers with MBC were included. Confirmed partial response (PR) occurred in 6 of 35 assessable patients [ORR = 17%; 95% confidence interval (CI) 7% to 34%] and lasted 1.4-6.8 months. Median PFS was 3.9 months (95% CI 1.6-5.5 months). Eight patients (21%) showed changes in tumor volume, and 14 (40%) a clinical benefit. Trabectedin-related adverse events were generally mild/moderate, the most common being fatigue, nausea, constipation and anorexia. Severe laboratory abnormalities (neutropenia, transaminase increases) were mostly transient and noncumulative, and were managed by dose adjustments. CONCLUSIONS: With the caveat of the limited patient number, trabectedin monotherapy showed activity and was well tolerated in heavily pretreated MBC patients selected for germline BRCA mutation. These results prompt further evaluation of trabectedin alone or combined with other specific drugs in this indication. CLINICALTRIALSGOV: NCT00580112.

Phase I-II study of plitidepsin and dacarbazine as first-line therapy for advanced melanoma.

BACKGROUND: This phase I-II trial compared plitidepsin 1-h infusion alone or combined with dacarbazine (DTIC) 1-h infusion as front-line therapy for advanced melanoma. METHODS: The recommended dose (RD) for plitidepsin/DTIC was defined in the first stage. In the second stage, patients were randomised to receive single-agent plitidepsin 3.2 mg m(-2) (n = 20) on days 1, 8 and 15 every 4 weeks (q4wk) or plitidepsin 2.4 mg m(-2) on days 1, 8 and 15 q4wk combined with DTIC 800 mg m(-2) q4wk (n = 38). RESULTS: The overall response rate with plitidepsin/DTIC was 21.4%; all responders had normal serum lactate dehydrogenase (LDH) levels and performance status ≤ 1 at baseline. Median progression-free survival (PFS) with plitidepsin/DTIC was 3.3 months in all patients, and 4.3 months in those with baseline normal LDH. No responses occurred with single-agent plitidepsin and median PFS was 1.5 months. Both regimens were well tolerated. Haematological abnormalities were more common and transaminase increases more severe with plitidepsin/DTIC. Treatment-related transaminase increases leading to infusion omission on day 8 were relatively common. No drug-drug pharmacokinetic interactions were found. CONCLUSION: This plitidepsin/DTIC schedule has antitumour activity and manageable toxicity in advanced melanoma. Further evaluation of plitidepsin 2.4 mg m(-2) fortnightly and DTIC 800 mg m(-2) q4wk is recommended.

Multicenter phase II study of trabectedin in patients with metastatic castration-resistant prostate cancer.

BACKGROUND: This multicenter phase II trial evaluated the efficacy and safety of trabectedin in metastatic castration-resistant prostate cancer (CRPC). PATIENTS AND METHODS: Two schedules were evaluated in three cohorts: weekly as 3-h i.v. infusion at 0.58 mg/m(2) for 3 out of 4 weeks (Cohort A, n = 33), and every 3 weeks (q3wk) as 24-h infusion at 1.5 mg/m(2) (Cohort B1, n = 5) and 1.2 mg/m(2) (Cohort B2, n = 20). The primary end point was prostate-specific antigen (PSA) response; secondary end points included safety, tolerability and time to progression (TTP). RESULTS: Trabectedin resulted in PSA declines ≥ 50% in 12.5% (Cohort A) and 10.5% (Cohort B2) of patients. Among men pretreated with taxane-based chemotherapy, PSA response was 13.6% (Cohort A) and 15.4% (Cohort B2). PSA responses lasted 4.1-8.6 months, and median TTP was 1.5 months (Cohort A) and 1.9 months (Cohort B2). The dose of 1.5 mg/m(2) (approved for soft tissue sarcoma) given as 24-h infusion q3wk was not tolerable in these patients. At 1.2 mg/m(2) q3wk and 0.58 mg/m(2) weekly, the most common adverse events were nausea, fatigue and transient neutropenia and transaminase increase. CONCLUSIONS: Two different trabectedin schedules showed modest activity in metastatic CRPC. Further studies may require identification of predictive factors of response in prostate cancer.

Antitumor activity of lurbinectedin in combination with oral capecitabine in patients with metastatic breast cancer.

BACKGROUND: Preclinical studies showed a synergistic effect for 5-fluorouracil and lurbinectedin against solid tumors. This phase I trial evaluated a combination of capecitabine plus lurbinectedin in patients with selected advanced solid tumors. Results in patients with relapsed metastatic breast cancer (MBC) are described. PATIENTS AND METHODS: Patients received capecitabine daily on day (D)1-D14 combined with lurbinectedin on D1, D8 or D1 every 3 weeks (q3w) intravenously, following a standard 3 + 3 escalation design and expansion at the recommended dose (RD). RESULTS: Of the 81 enrolled patients, 28 had relapsed MBC: 20 with hormone receptor (HR)-positive tumors and 8 with triple-negative tumors; 3 treated in the D1,D8 schedule and 25 in the D1 schedule. The RD was capecitabine 1650 mg/m2 daily on D1-D14 plus lurbinectedin 2.2 mg/m2 on D1 q3w. Sixteen confirmed responses and two prolonged disease stabilizations (≥6 months) were observed [overall response rate (ORR)/clinical benefit rate (CBR) = 57%/64% at all dose levels; 47%/60% at the RD]. Twelve responses and both prolonged stabilizations occurred in HR-positive tumors (ORR/CBR = 60%/70% at all dose levels, 56%/78% at the RD). Four responses were found in triple-negative tumors (ORR and CBR = 50% at all dose levels; 33% at the RD). Myelotoxicity was reversible and manageable at the RD; most non-hematological toxicities were mild/moderate. No episodes of febrile neutropenia or severe palmar-plantar erythrodysesthesia syndrome occurred. No major pharmacokinetic drug-drug interaction was found between lurbinectedin, capecitabine or capecitabine metabolites. CONCLUSIONS: The capecitabine/lurbinectedin combination showed encouraging clinical activity in relapsed MBC, especially in HR-positive tumors. Toxicity was manageable at the RD. Further development is warranted in relapsed MBC.

Lurbinectedin, a selective inhibitor of oncogenic transcription, in patients with pretreated germline BRCA1/2 metastatic breast cancer: results from a phase II basket study.

BACKGROUND: Lurbinectedin, a selective inhibitor of oncogenic transcription, has shown preclinical antitumor activity against homologous recombination repair-deficient models and preliminary clinical activity in BRCA1/2 breast cancer. PATIENTS AND METHODS: This phase II basket multitumor trial (NCT02454972) evaluated lurbinectedin 3.2 mg/m2 1-h intravenous infusion every 3 weeks in a cohort of 21 patients with pretreated germline BRCA1/2 breast cancer. Patients with any hormone receptor and human epidermal growth factor receptor 2 status were enrolled. The primary efficacy endpoint was overall response rate (ORR) according to RECIST v1.1. Secondary endpoints included duration of response (DoR), progression-free survival (PFS), overall survival (OS) and safety. RESULTS: Confirmed partial response (PR) was observed in six patients [ORR = 28.6%; 95% confidence interval (CI) 11.3% to 52.2%] who had received a median of two prior advanced chemotherapy lines. Lurbinectedin was active in both BRCA mutations: four PRs in 11 patients (36.4%) with BRCA2 and two PRs in 10 patients (20.0%) with BRCA1. Median DoR was 8.6 months, median PFS was 4.1 months and median OS was 16.1 months. Stable disease (SD) was observed in 10 patients (47.6%), including 3 with unconfirmed response in a subsequent tumor assessment [ORR unconfirmed = 42.9% (95% CI 21.8% to 66.0%)]. Clinical benefit rate (PR + SD ≥ 4 months) was 76.2% (95% CI 52.8% to 91.8%). No objective response was observed among patients who had received prior poly (ADP-ribose) polymerase inhibitors. The most common treatment-related adverse events (AEs) were nausea (61.9%), fatigue (38.1%) and vomiting (23.8%). These AEs were mostly grade 1/2. The most common grade 3/4 toxicity was neutropenia (42.9%: grade 4, 23.8%: with no febrile neutropenia). CONCLUSIONS: This phase II study met its primary endpoint and showed activity of lurbinectedin in germline BRCA1/2 breast cancer. Lurbinectedin showed a predictable and manageable safety profile. Considering the exploratory aim of this trial as well as previous results in other phase II studies, further development of lurbinectedin in this indication is warranted.

Phase II study of ecteinascidin-743 in advanced pretreated soft tissue sarcoma patients.

PURPOSE: A multicenter phase II study evaluating efficacy, safety, and pharmacokinetics of ecteinascidin-743 (ET-743) in pretreated advanced soft tissue sarcoma patients. PATIENTS AND METHODS: Patients received ET-743 1,500 microg/m(2) (24-hour intravenous infusion) every 3 weeks (group 1, 26 patients with one to two prior single agents or one previous combination chemotherapy; group 2, 28 patients with three or more prior single agents or two or more previous combination chemotherapies). Results Patients (30 women, 24 men) had a median age of 48 years (range, 22 to 71 years); 41% had leiomyosarcoma (eight of 22 of uterine origin), a median of two involved organs (range, one to four), and 93% had documented progressive disease at study entry. Patients received a median of three cycles (range, one to 20); 28% received six or more cycles. Fifty-two patients were assessable for response (WHO criteria): two partial responses, four minor responses, and nine with stable disease (> or = 6 months). Three patients were rendered tumor free after surgery. Median progression-free survival was 1.9 months (range, 0.69 to 17.90 months); 24% of patients were progression free at 6 months. Median survival was 12.8 months, with 30% of patients alive at 2 years. Four patients withdrew because of treatment-related toxicity. Two treatment-related deaths occurred (renal failure and febrile neutropenia, and rhabdomyolysis and decompensated cirrhosis, respectively) that were probably related to protocol eligibility violations. Reversible grade 3 to 4 AST or ALT occurred in 50% of patients and grade 3 to 4 neutropenia occurred in 61% of patients, with six episodes of febrile neutropenia. Nausea, vomiting, and asthenia were prevalent but mild and manageable. CONCLUSION: With a 4% overall response rate (95% CI, 0.5 to 12.8) and an 11% rate of third-party-verified tumor regression (overall response rate + minor response), ET-743 has a 24% 6-month disease progression control rate, confirming evidence of antitumoral activity and a manageable safety profile in patients experiencing disease progression with pretreated soft tissue sarcoma.

A phase II study of neoadjuvant gemcitabine plus doxorubicin in stage IIIB breast cancer: a preliminary report.

The purpose of this ongoing study is to determine the response and safety of a combination of gemcitabine (Gemzar; Eli Lilly and Company, Indianapolis, IN) plus doxorubicin as neoadjuvant therapy for stage IIIB breast cancer. Thirty-nine chemotherapy-naive patients were enrolled in the study. The median age was 54 years (range, 32 to 74 years), and the median Karnofsky performance status was 100. Gemcitabine 1,200 mg/m(2) was given on days 1 and 8, and doxorubicin 60 mg/m(2) on day 1, followed by surgery or radiotherapy. Ninety-seven of 117 cycles (83%) were administered at full dose. An overall response rate of 95% was obtained, with a complete response in 18% (seven patients) and a partial response in 77% (30 patients). Twenty-eight patients (72%) underwent breast surgery after a maximum of three cycles of neoadjuvant therapy. World Health Organization grade 3/4 toxicities included leukopenia in nine cycles (8%), neutropenia in 16 cycles (14%), febrile neutropenia in 11 cycles (9%), and anemia in two cycles (2%). The most important nonhematologic toxicity was grade 2/4 mucositis in 16 cycles (14%), and/or grade 2/3 diarrhea in 10 cycles (9%). Neoadjuvant therapy with gemcitabine plus doxorubicin results in a high tumor response rate with moderate oral and hematologic toxicity. Semin Oncol 28 (suppl 10):57-61.

A phase I pharmacokinetic study of PM00104 (Zalypsis) administered as a 24-h intravenous infusion every 3 weeks in patients with advanced solid tumors.

PURPOSE: PM00104 (Zalypsis) is a synthetic tetrahydroisoquinoline alkaloid with potent antiproliferative activity against tumor cell lines. This phase I study evaluated the safety, dose-limiting toxicities (DLTs), recommended dose for phase II trials (RD), pharmacokinetics (PK) and preliminary antitumor activity of PM00104 as a 24-h intravenous (i.v.) infusion every 3 weeks (q3wk). METHODS: Thirty-seven patients with refractory advanced solid tumors received PM00104 in a toxicity-guided dose escalation study design (3 + 3 patients per cohort). Plasma samples were collected for PK analysis. RESULTS: DLTs comprised severe neutropenia lasting >5 days (n = 4 patients), vomiting, thrombocytopenia, transaminase increases (n = 2 each), fatigue, tumor pain, myalgia, muscle stiffness, creatine phosphokinase increase and dosing delay >2 weeks due to moderate fatigue (n = 1 each). The RD was 4.0 mg/m(2). Most PM00104-related adverse events at the RD were mild or moderate; the most common were nausea, vomiting and fatigue. Myelosuppression and transaminase increases were transient and manageable. PK parameters increased linearly with dose. Higher PM00104 PK exposure was related to a decrease in hemoglobin, neutrophils, platelets and white blood cells. Area under the curve was directly correlated with both incidence and severity of nausea and vomiting. Three patients with hepatocellular carcinoma, esophageal adenocarcinoma and prostate adenocarcinoma had response evaluation criteria in solid tumors stable disease ≥3 months. CONCLUSIONS: PM00104 given as 24-h i.v. infusion q3wk has predictable and manageable toxicity, but resulted in more myelotoxicity (because of the higher dose level achieved as the RD) and a similar drug clearance compared to 1-h infusion schedules. Preliminary evidence of antitumor activity was observed.