Pharmacokinetics and Safety of Lurbinectedin Administrated with Itraconazole in Cancer Patients: A Drug-Drug Interaction Study

This open-label, two-part, phase Ib drug-drug interaction study investigated whether the pharmacokinetic (PK) and safety profiles of lurbinectedin (LRB), a marine-derived drug, are affected by co-administration of itraconazole (ITZ), a strong CYP3A4 inhibitor, in adult patients with advanced solid tumors. In Part A, three patients were sequentially assigned to Sequence 1 (LRB 0.8 mg/m2, 1-h intravenous [IV] + ITZ 200 mg/day oral in Cycle 1 [C1] and LRB alone 3.2 mg/m2, 1 h, IV in Cycle 2 [C2]). In Part B, 11 patients were randomized (1:1) to receive either Sequence 1 (LRB at 0.9 mg/m2 + ITZ in C1 and LRB alone in C2) or Sequence 2 (LRB alone in C1 and LRB + ITZ in C2). Eleven patients were evaluable for PK analysis: three in Part A and eight in Part B (four per sequence). The systemic total exposure of LRB increased with ITZ co-administration: 15% for Cmax, area under the curve (AUC) 2.4-fold for AUC0-t and 2.7-fold for AUC0-∞. Co-administration with ITZ produced statistically significant modifications in the unbound plasma LRB PK parameters. The LRB safety profile was consistent with the toxicities described in previous studies. Co-administration with multiple doses of ITZ significantly altered LRB systemic exposure. Hence, to avoid LRB overexposure when co-administered with strong CYP3A4 inhibitors, an LRB dose reduction proportional to CL reduction should be applied.

Lurbinectedin in patients with small cell lung cancer with chemotherapy-free interval ≥30 days and without central nervous metastases

OBJECTIVES

This report focuses on lurbinectedin activity and safety in a subgroup of small cell lung cancer (SCLC) patients from a Basket phase 2 study (Trigo et al. Lancet Oncology 2020;21:645-654) with chemotherapy-free interval (CTFI) ≥ 30 days. This pre-planned analysis was requested for obtaining regulatory approval of lurbinectedin in Switzerland.

MATERIALS AND METHODS

Patients with extensive-stage SCLC, no central nervous system (CNS) metastases, and disease progression after platinum-containing therapy were included. Topotecan data from a contemporary, randomized, controlled phase 3 study (ATLANTIS) were used as indirect external control in a matched patient population (n = 98 patients).

RESULTS

Lurbinectedin showed a statistically significant higher overall response rate (ORR) by investigator assessment (IA) compared to topotecan subgroup (41.0 % vs. 25.5 %; p = 0.0382); higher ORR by Independent Review Committee (IRC) (33.7 % vs. 25.5 %); longer median duration of response (IA: 5.3 vs. 3.9 months; IRC: 5.1 vs. 4.3 months), and longer median overall survival (10.2 vs. 7.6 months). Grade ≥ 3 hematological abnormalities were remarkably lower with lurbinectedin: anemia 12.0 % vs. 54.1 %; leukopenia 30.1 % vs. 68.4 %; neutropenia 47.0 % vs. 75.5 %, and thrombocytopenia 6.0 % vs. 52.0 %. Febrile neutropenia was observed at a higher incidence with topotecan (6.1 % vs. 2.4 % with lurbinectedin) despite that the use of growth-colony stimulating factors was mandatory with topotecan.

CONCLUSION

With the limitations of an indirect comparison, however using recent and comparable SCLC datasets, this post hoc analysis shows that SCLC patients with CTFI ≥ 30 days and no CNS metastases have a positive benefit/risk ratio with lurbinectedin, superior to that observed with topotecan.

Impact of a Moderate CYP3A4 Inducer (Bosentan) on Lurbinectedin Pharmacokinetics and Safety in Patients with Advanced Solid Tumors: An Open-Label, Two-Way, Crossover, Phase Ib Drug-Drug Interaction Study

This open-label, two-way, crossover, phase Ib drug-drug interaction study investigated whether the pharmacokinetics (PKs) and safety profile of lurbinectedin (LRB) are affected by co-administration of a moderate CYP3A4 inducer (bosentan, BOS) in adult patients with advanced solid tumors. Eleven patients were randomly assigned to Sequence 1 (LRB + BOS in Cycle 1 [C1] and LRB alone in Cycle 2 [C2]) or Sequence 2 (LRB alone in C1 and LRB + BOS in C2), and finally, eight patients (four per sequence) were considered evaluable for PK assessment. LRB (3.2 mg/m2, 1 h [h], intravenous) was administered alone or combined with multiple BOS administration (125 mg/12 h oral; 5.5 days). Co-administration with BOS decreased the systemic total exposure (area under the curve, AUC) of LRB by 21% for AUC0-t and 20% for AUC0-∞ and increased clearance by 25%. Co-administration with BOS did not significantly modify the unbound plasma LRB PK parameters. BOS increased the conversion of LRB to its metabolite M1, with no changes on its metabolite M4. The LRB safety profile was consistent with the toxicities previously described for this drug. No differences in terms of toxicity were found between LRB with and without BOS. In summary, the magnitude of the observed changes precludes a clinically relevant effect of BOS co-administration on LRB exposure and its safety profile.

Pooled Safety Analysis of Single-Agent Lurbinectedin in Patients With Advanced Solid Tumours

BACKGROUND

Lurbinectedin was approved by FDA and other health regulatory agencies for treating adults with metastatic small cell lung cancer (SCLC) with disease progression on or after platinum-based chemotherapy. Safety profile at approved dose (3.2 mg/m2 every 3 weeks) was acceptable and manageable in 105 adult SCLC patients from a phase II basket trial. This study analyses safety data from several solid tumours treated at the lurbinectedin-approved dose.

METHODS

Data were pooled from 554 patients: 335 from all nine tumour-specific cohorts of the phase II basket trial and 219 from a randomised phase III trial (CORAIL) in platinum-resistant ovarian cancer. Events and laboratory abnormalities were graded using NCI-CTCAE v.4.

RESULTS

Most common tumours were ovarian (n = 219, 40%), SCLC (n = 105, 19%) and endometrial (n = 73, 13%). Transient haematological laboratory abnormalities were the most frequent grade 3 or more events: neutropenia (41%), leukopenia (30%), anaemia (17%) and thrombocytopenia (10%). Most common treatment-emergent non-haematological events (any grade) were transient transaminase increases (alanine aminotransferase [66%], aspartate aminotransferase [53%]), fatigue (63%), nausea (57%), constipation (32%), vomiting (30%) and decreased appetite (25%). Dose reductions were mostly due to haematological toxicities, but most patients (79%) remained on full lurbinectedin dose. Serious events mostly consisted of haematological disorders. Eighteen treatment discontinuations (3%) and seven deaths (1%) were due to treatment-related events.

CONCLUSIONS

This analysis confirms a manageable safety profile for lurbinectedin in patients with advanced solid tumours. Findings are consistent with those reported in patients with relapsed SCLC, Ewing sarcoma, germline BRCA1/2 metastatic breast cancer, neuroendocrine tumours and ovarian cancer.

Lurbinectedin in patients with pretreated endometrial cancer: results from a phase 2 basket clinical trial and exploratory translational study

Second-line treatment of endometrial cancer is an unmet medical need. Lurbinectedin showed promising antitumor activity in a phase I study in combination with doxorubicin in advanced endometrial cancer. This phase 2 Basket trial evaluated lurbinectedin 3.2 mg/m2 1-h intravenous infusion every 3 weeks in a cohort of 73 patients with pretreated endometrial cancer. The primary 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), safety and an exploratory translational study. Confirmed complete (CR) and partial response (PR) was reported in two and six patients, respectively (ORR = 11.3%; 95%CI, 5.0-21.0%). Median DoR was 9.2 months (95%CI, 3.4-18.0 months), median PFS was 2.6 months (95%CI, 1.4-4.0 months) and median OS was 9.3 months (95%CI, 6.1-12.8 months). Molecular subtypes showed differences in PFS rate at 6 months (p53abn 23.7% vs. "No Specific Molecular Profile" [NSMP] 42.9%) and median OS (p53abn 6.6 months vs. NSMP 16.1 months). The most common treatment-related adverse events (mostly grade 1/2) were fatigue (54.8% of patients), nausea (50.7%), vomiting (26.0%) decreased appetite (17.8%). and constipation, (19.2%). The most common grade 3/4 toxicity was neutropenia (43.8%; grade 4, 19.2%; febrile neutropenia, 4.1%). In conclusion, considering the exploratory aim of this trial and the hints of antitumor activity observed together with a predictable and manageable safety profile, further biomarker-based development of lurbinectedin is recommended in this indication in combination with other agents. Clinicaltrials.gov identifier: NCT02454972.

Phase I study of plitidepsin in combination with bortezomib and dexamethasone in patients with relapsed/refractory multiple myeloma

Previous studies showed antitumor activity for plitidepsin plus dexamethasone (DXM) in relapsed/refractory multiple myeloma (r/r MM), and in vitro synergism with bortezomib (BTZ) or DXM against MM cells. This phase I trial evaluated plitidepsin (3-h intravenous infusion Day 1 and 15), BTZ (subcutaneous bolus Day 1, 4, 8, and 11), and DXM (orally Day 1, 8, 15, and 22), every 4 weeks in 36 r/r MM patients. Twenty-two patients were treated using a standard dose escalation design (10 at the recommended dose [RD] cohort), and 14 additional patients were treated to expand the RD cohort. No dose-limiting toxicities (DLTs) occurred during dose escalation. The highest dose level evaluated (plitidepsin 5.0 mg/m² , BTZ 1.3 mg/m² , DXM 40.0 mg) was the RD for phase II studies. Results shown herein are focused on this RD. Two patients had DLTs (grade 3 diarrhea, and grade 3 nausea/vomiting refractory to antiemetic therapy). Grade ≥ 3 hematological toxicity (thrombocytopenia 46%, anemia 33%, and neutropenia 17%) was manageable and did not result in treatment discontinuation. Transient and manageable grade 3 ALT increase (26%) was the most common biochemical abnormality. At the RD cohort, overall response rate was 22.2% (95%CI, 6.4%-47.6%), including one stringent complete response, one very good partial response, and two partial responses in r/r patients to BTZ and/or lenalidomide. The clinical benefit rate was 77.8% (95%CI, 52.4-93.6%). No major pharmacokinetic drug-drug interaction was found. In conclusion, the triple combination of plitidepsin, BTZ, and DXM showed an acceptable safety profile and had moderate activity in adult patients with r/r MM.

Combination lurbinectedin and doxorubicin versus physician's choice of chemotherapy in patients with relapsed small-cell lung cancer (ATLANTIS): a multicentre, randomised, open-label, phase 3 trial

BACKGROUND

Lurbinectedin is a synthetic marine-derived anticancer agent that acts as a selective inhibitor of oncogenic transcription. Lurbinectedin monotherapy (3·2 mg/m² every 3 weeks) received accelerated approval from the US Food and Drug Administration on the basis of efficacy in patients with small-cell lung cancer (SCLC) who relapsed after first-line platinum-based chemotherapy. The ATLANTIS trial assessed the efficacy and safety of combination lurbinectedin and the anthracycline doxorubicin as second-line treatment for SCLC.

METHODS

In this phase 3, open-label, randomised study, adult patients aged 18 years or older with SCLC who relapsed after platinum-based chemotherapy were recruited from 135 hospitals across North America, South America, Europe, and the Middle East. Patients were randomly assigned (1:1) centrally by dynamic allocation to intravenous lurbinectedin 2·0 mg/m² plus doxorubicin 40·0 mg/m² administered on day 1 of 21-day cycles or physician's choice of control therapy (intravenous topotecan 1·5 mg/m² on days 1-5 of 21-day cycles; or intravenous cyclophosphamide 1000 mg/m², doxorubicin 45·0 mg/m², and vincristine 2·0 mg on day 1 of 21-day cycles [CAV]) administered until disease progression or unacceptable toxicity. Primary granulocyte-colony stimulating factor prophylaxis was mandatory in both treatment groups. Neither patients nor clinicians were masked to treatment allocation, but the independent review committee, which assessed outcomes, was masked to patients' treatment allocation. The primary endpoint was overall survival in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, NCT02566993, and with EudraCT, 2015-001641-89, and is complete.

FINDINGS

Between Aug 30, 2016, and Aug 20, 2018, 613 patients were randomly assigned to lurbinectedin plus doxorubicin (n=307) or control (topotecan, n=127; CAV, n=179) and comprised the intention-to-treat population; safety endpoints were assessed in patients who had received any partial or complete study treatment infusions (lurbinectedin plus doxorubicin, n=303; control, n=289). After a median follow-up of 24·1 months (95% CI 21·7-26·3), 303 patients in the lurbinectedin plus doxorubicin group and 289 patients in the control group had discontinued study treatment; progressive disease was the most common reason for discontinuation (213 [70%] patients in the lurbinectedin plus doxorubicin group vs 152 [53%] in the control group). Median overall survival was 8·6 months (95% CI 7·1-9·4) in the lurbinectedin plus doxorubicin group versus 7·6 months (6·6-8·2) in the control group (stratified log-rank p=0·90; hazard ratio 0·97 [95% CI 0·82-1·15], p=0·70). 12 patients died because of treatment-related adverse events: two (<1%) of 303 in the lurbinectedin plus doxorubicin group and ten (3%) of 289 in the control group. 296 (98%) of 303 patients in the lurbinectedin plus doxorubicin group had treatment-emergent adverse events compared with 284 (98%) of 289 patients in the control group; treatment-related adverse events occurred in 268 (88%) patients in the lurbinectedin plus doxorubicin group and 266 (92%) patients in the control group. Grade 3 or worse haematological adverse events were less frequent in the lurbinectedin plus doxorubicin group than the control group (anaemia, 57 [19%] of 302 patients in the lurbinectedin plus doxorubicin group vs 110 [38%] of 288 in the control group; neutropenia, 112 [37%] vs 200 [69%]; thrombocytopenia, 42 [14%] vs 90 [31%]). The frequency of treatment-related adverse events leading to treatment discontinuation was lower in the lurbinectedin plus doxorubicin group than in the control group (26 [9%] of 303 patients in the lurbinectedin plus doxorubicin group vs 47 [16%] of 289 in the control group).

INTERPRETATION

Combination therapy with lurbinectedin plus doxorubicin did not improve overall survival versus control in patients with relapsed SCLC. However, lurbinectedin plus doxorubicin showed a favourable haematological safety profile compared with control.

FUNDING

PharmaMar.

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.

Lurbinectedin in patients with pretreated neuroendocrine tumours: Results from a phase II basket study

BACKGROUND

Patients with neuroendocrine tumours (NETs) need alternative therapies after failure of first-line therapy.

PATIENTS AND METHODS

This phase II trial evaluated lurbinectedin, a selective inhibitor of oncogenic transcription, at 3.2 mg/m² as a 1-h intravenous infusion every 3 weeks in 32 NETs patients treated in the second- or third-line setting. The primary efficacy endpoint was overall response rate (ORR) according to RECIST v1.1 assessed by the investigators. Secondary endpoints included duration of response (DoR), progression-free survival (PFS), overall survival (OS) and safety.

RESULTS

Two of 31 evaluable patients had confirmed partial responses (ORR = 6.5%; 95%CI, 0.8-21.4%). Median DoR was 4.7 months (95% CI, 4.0-5.4 months), median PFS was 1.4 months (95% CI, 1.2-3.0 months) and median OS was 7.4 months (95% CI, 3.4-16.2 months). Lurbinectedin showed an acceptable, predictable and manageable safety profile. The most common grade 3/4 toxicity was neutropenia (40.6%; grade 4, 12.4%; febrile neutropenia, 3.1%).

CONCLUSIONS

Considering the exploratory aim of this trial that evaluated a heterogeneous population of NETs patients, and the signs of antitumour activity observed (two confirmed partial responses and seven long disease stabilisations), further development of lurbinectedin is warranted in a more selected NETs population.

TRIAL REGISTRATION NUMBER

Sponsor Study Code: PM1183-B-005-14. EudraCT number: 2014-003773-42.

CLINICALTRIALS

gov reference: NCT02454972.

Antitumor Activity of Lurbinectedin, a Selective Inhibitor of Oncogene Transcription, in Patients with Relapsed Ewing Sarcoma: Results of a Basket Phase II Study

PURPOSE

Lurbinectedin suppresses the oncogenic transcription factor EWS-FLI1 through relocalization to the nucleolus, and delays tumor growth in mice bearing Ewing sarcoma xenografts. On the basis of this rationale, lurbinectedin was evaluated in patients with relapsed Ewing sarcoma.

PATIENTS AND METHODS

This open-label, single-arm, Basket phase II trial included a cohort of 28 treated adult patients with confirmed Ewing sarcoma, measurable disease as per Response Evaluation Criteria In Solid Tumors (RECIST) v.1.1, Eastern Cooperative Oncology Group performance status ≤2, adequate organ function, no central nervous system metastasis, and pretreated with ≤2 chemotherapy lines for metastatic/recurrent disease. Patients received lurbinectedin 3.2 mg/m2 as a 1-hour infusion every 3 weeks. Primary endpoint was overall response rate (ORR) as per RECIST v.1.1. Secondary endpoints included time-to-event parameters and safety profile.

RESULTS

ORR was 14.3% [95% confidence interval (CI), 4.0%-32.7%], with median duration of response of 4.2 months (95% CI, 2.9-5.5 months). Median progression-free survival was 2.7 months (95% CI, 1.4-4.3 months), clinical benefit rate was 39.3%, and disease control rate was 57.1%. With 39% censoring, median overall survival was 12.0 months (95% CI, 8.5-18.5 months). Most common grade 3/4 adverse events were neutropenia (57%), anemia, thrombocytopenia, and treatment-related febrile neutropenia (14% each). No deaths or discontinuations were due to toxicity.

CONCLUSIONS

Lurbinectedin was active in the treatment of relapsed Ewing sarcoma and had a manageable safety profile. Lurbinectedin could represent a valuable addition to therapies for Ewing sarcoma, and is currently being evaluated in combination with irinotecan in advanced Ewing sarcoma in a phase Ib/II trial.

Phase I study of lurbinectedin in combination with weekly paclitaxel with or without bevacizumab in patients with advanced solid tumors

Lurbinectedin and paclitaxel showed synergism in preclinical studies and have non-completely overlapping toxicity profiles. This phase I trial evaluated a combination of paclitaxel and lurbinectedin with/without bevacizumab in advanced tumors. This trial was divided into Group A, which evaluated weekly paclitaxel (60 or 80 mg) plus lurbinectedin (3.0-5.0 mg flat dose [FD] or 2.2 mg/m²) every 3 weeks in advanced solid tumors; and Group B, which evaluated bevacizumab (BEV, 15 mg/kg) added to the recommended dose (RD) defined in Group A in advanced epithelial ovarian or non-small cell lung cancer (NSCLC). 67 patients (A, n = 55; B, n = 12) were treated. The RD was paclitaxel 80 mg/m² on Day (D)1,D8 plus lurbinectedin 2.2 mg/m² on D1. At this RD, myelotoxicity was reversible and manageable, and most non-hematological toxicities were mild/moderate. Adding BEV did not notably change tolerability. Twenty-five confirmed responses were observed: 20/51 evaluable patients in Group A (overall response rate [ORR] = 39% at all dose levels and at the RD), and 5/10 evaluable patients in Group B (ORR = 50%). Most responders had breast (n = 7/12 patients), small cell lung (SCLC) (n = 5/7), epithelial ovarian (n = 3/9) and endometrial cancer (n = 3/11) in Group A, and epithelial ovarian (n = 3/4) and NSCLC (n = 2/6) in Group B. Clinical benefit rate was 61% in Group A (58% at the RD), and 90% in Group B. No major pharmacokinetic drug-drug interactions were observed. Paclitaxel/lurbinectedin and paclitaxel/lurbinectedin/BEV are feasible combinations. Further development is warranted of paclitaxel/lurbinectedin in SCLC, breast, and endometrial cancer, and of paclitaxel/lurbinectedin/BEV in epithelial ovarian cancer.

Doxorubicin plus lurbinectedin in patients with advanced endometrial cancer: results from an expanded phase I study

Objective

Second-line treatment of endometrial cancer is an unmet medical need. We conducted a phase I study evaluating lurbinectedin and doxorubicin intravenously every 3 weeks in patients with solid tumors. The aim of this study was to characterise the efficacy and safety of lurbinectedin and doxorubicin for patients with endometrial cancer.

Methods

Thirty-four patients were treated: 15 patients in the escalation phase (doxorubicin 50 mg/m² and lurbinectedin 3.0–5.0 mg) and 19 patients in the expansion cohort (doxorubicin 40 mg/m² and lurbinectedin 2.0 mg/m²). All histological subtypes were eligible and patients had received one to two prior lines of chemotherapy for advanced disease. Antitumor activity was evaluated every two cycles according to the Response Evaluation Criteria in Solid Tumors version 1.1. Adverse events were graded according to the National Cancer Institute-Common Terminology Criteria for Adverse Events version 4.

Results

Median age (range) was 65 (51–78) years. Eastern Cooperative Oncology Group performance status was up to 1 in 97% of patients. In the escalation phase, 4 (26.7%) of 15 patients had confirmed response: two complete and two partial responses (95% CI 7.8% to 55.1%). Median duration of response was 19.5 months. Median progression-free survival was 7.3 (2.5 to 10.1) months. In the expansion cohort, confirmed partial response was reported in 8 (42.1%) of 19 patients (95% CI 20.3% to 66.5%). Median duration of response was 7.5 (6.4 to not reached) months, median progression-free survival was 7.7 (2.0 to 16.7) months and median overall survival was 14.2 (4.5 to not reached) months. Fatigue (26.3% of patients), and transient and reversible myelosuppression (neutropenia, 78.9%; febrile neutropenia, 21.1%; thrombocytopenia, 15.8%) were the main grade 3 and higher toxicities in the expanded cohort.

Conclusions

In patients with recurrent advanced endometrial cancer treated with doxorubicin and lurbinectedin, response rates (42%) and duration of response (7.5 months) were favorable. Further evaluation of doxorubicin and lurbinectedin is warranted in this patient population.

Lurbinectedin versus pegylated liposomal doxorubicin or topotecan in patients with platinum-resistant ovarian cancer: A multicenter, randomized, controlled, open-label phase 3 study (CORAIL)

OBJECTIVE

The randomized phase 3 CORAIL trial evaluated whether lurbinectedin improved progression-free survival (PFS) compared to pegylated liposomal doxorubicin (PLD) or topotecan in patients with platinum-resistant ovarian cancer.

METHODS

Patients were randomly assigned (1:1) to lurbinectedin 3.2 mg/m² 1-h i.v. infusion q3wk (experimental arm), versus PLD 50 mg/m² 1-h i.v. infusion q4wk or topotecan 1.50 mg/m² 30-min i.v. infusion Days 1-5 q3wk (control arm). Stratification factors were PS (0 vs. ≥1), prior PFI (1-3 months vs. >3 months), and prior chemotherapy lines (1-2 vs. 3). The primary endpoint was PFS by Independent Review Committee in all randomized patients. This study was registered with ClinicalTrials.gov, NCT02421588.

RESULTS

442 patients were randomized: 221 in lurbinectedin arm and 221 in control arm (127 PLD and 94 topotecan). With a median follow-up of 25.6 months, median PFS was 3.5 months (95% CI, 2.1-3.7) in the lurbinectedin arm and 3.6 months (95% CI, 2.7-3.8) in the control arm (stratified log-rank p = 0.6294; HR = 1.057). Grade ≥ 3 treatment-related adverse events (AEs) were most frequent in the control arm: 64.8% vs. 47.9% (p = 0.0005), mainly due to hematological toxicities. The most common grade ≥ 3 AEs were: fatigue (7.3% of patients) and nausea (5.9%) with lurbinectedin; mucosal inflammation (8.5%) and fatigue (8.0%) in the control arm.

CONCLUSIONS

The primary endpoint of improvement in PFS was not met. Lurbinectedin showed similar antitumor efficacy and was better tolerated than current standard of care in patients with platinum-resistant ovarian cancer.

A phase I trial of lurbinectedin in combination with cisplatin in patients with advanced solid tumors

Background In vitro/in vivo data showed synergism of cisplatin and lurbinectedin in ovarian cancer cells and grafts. This phase I trial investigated the recommended phase II dose (RD) of cisplatin and lurbinectedin combination, with (Group A) or without aprepitant (Group B), in patients with advanced solid tumors. Patients and Methods All patients received 60 mg/m² cisplatin 90-min intravenous (i.v.) infusion followed by lurbinectedin 60-min i.v. infusion at escalating doses on Day 1 every 3 weeks (q3wk). Patients in Group A additionally received orally 125 mg aprepitant one hour before cisplatin on Day 1 and 80 mg on Days 2 and 3. Toxicity was graded according to the NCI-CTCAE v.4. Results RD for Group A was cisplatin 60 mg/m² plus lurbinectedin 1.1 mg/m². RD for Group B was cisplatin 60 mg/m² plus lurbinectedin 1.4 mg/m². The most frequent grade ≥ 3 adverse events were hematological [neutropenia (41%), lymphopenia (35%), leukopenia (24%), thrombocytopenia (18%)] and fatigue (35%) in Group A (n = 17), and neutropenia (50%), leukopenia (42%), lymphopenia (29%), and fatigue (13%) and nausea (8%) in Group B (n = 24). Four patients (2 in each group) had a partial response. Disease stabilization for ≥ 4 months was observed in 4 and 10 patients, respectively. Conclusion The combination of lurbinectedin with cisplatin was not possible in meaningful therapeutic dosage due to toxicity. The addition of aprepitant in combination with cisplatin did not allow increasing the dose due to hematological toxicity, whereas omitting aprepitant increased the incidence of nausea and vomiting. Modest clinical activity was observed in general.Clinical trial registration www.ClinicalTrials.gov code: NCT01980667. Date of registration: 11 November 2013.

Lurbinectedin in the treatment of relapsed small cell lung cancer

Lurbinectedin is a marine-derived drug that inhibits transcription, a process that is frequently dysregulated in small cell lung cancer. The activity of lurbinectedin has been studied in many solid tumors, showing not only promising results but also a favorable safety profile. In relapsed small cell lung cancer, the drug has shown encouraging activity both as a single agent and in combination with doxorubicin, paclitaxel or irinotecan. The USA FDA has recently granted accelerated approval to lurbinectedin monotherapy in this setting. This article provides an update on available data and ongoing studies of lurbinectedin in small cell lung cancer, including Phase I combination trials, the basket Phase II trial and the ATLANTIS Phase III trial.

Efficacy and safety of lurbinectedin and doxorubicin in relapsed small cell lung cancer. Results from an expansion cohort of a phase I study

Background A phase I study found remarkable activity and manageable toxicity for doxorubicin (bolus) plus lurbinectedin (1-h intravenous [i.v.] infusion) on Day 1 every three weeks (q3wk) as second-line therapy in relapsed small cell lung cancer (SCLC). An expansion cohort further evaluated this combination. Patients and methods Twenty-eight patients with relapsed SCLC after no more than one line of cytotoxic-containing chemotherapy were treated: 18 (64%) with sensitive disease (chemotherapy-free interval [CTFI] ≥90 days) and ten (36%) with resistant disease (CTFI <90 days; including six with refractory disease [CTFI ≤30 days]). Results Ten patients showed confirmed response (overall response rate [ORR] = 36%); median progression-free survival (PFS) = 3.3 months; median overall survival (OS) = 7.9 months. ORR was 50% in sensitive disease (median PFS = 5.7 months; median OS = 11.5 months) and 10% in resistant disease (median PFS = 1.3 months; median OS = 4.6 months). The main toxicity was transient and reversible myelosuppression. Treatment-related non-hematological events (fatigue, nausea, decreased appetite, vomiting, alopecia) were mostly mild or moderate. Conclusion Doxorubicin 40 mg/m² and lurbinectedin 2.0 mg/m² on Day 1 q3wk has shown noteworthy activity in relapsed SCLC and a manageable safety profile. The combination is being evaluated as second-line therapy for SCLC in an ongoing, randomized phase III trial. Clinical trial registration www.ClinicalTrials.gov code: NCT01970540. Date of registration: 22 October, 2013.

Antitumor activity of lurbinectedin in second-line small cell lung cancer patients who are candidates for re-challenge with the first-line treatment

INTRODUCTION

The National Comprehensive Cancer Network guidelines recommend re-challenge with the first-line treatment for relapsed small cell lung cancer (SCLC) with chemotherapy-free interval (CTFI)≥180 days. A phase II study (NCT02454972) showed remarkable antitumor activity in SCLC patients treated with lurbinectedin 3.2 mg/m² 1 -h intravenous infusion every 3 weeks as second-line therapy. We report results for the pre-planned subset of patients with CTFI ≥ 180 days.

MATERIAL AND METHODS

Twenty patients aged ≥18 years with pathologically proven SCLC diagnosis, pretreated with only one prior platinum-containing line, no CNS metastases, and with CTFI ≥ 180 days were evaluated. The primary efficacy endpoint was the overall response rate (ORR) assessed by the Investigators according to RECIST v1.1.

RESULTS

ORR was 60.0 % (95 %CI, 36.1-86.9), with a median duration of response of 5.5 months (95 %CI, 2.9-11.2) and disease control rate of 95.0 % (95 %CI, 75.1-99.9). Median progression-free survival was 4.6 months (95 %CI, 2.6-7.3). With a censoring of 55.0 %, the median overall survival was 16.2 months (95 %CI, 9.6-upper level not reached). Of note, 60.9 % and 27.1 % of patients were alive at 1 and 2 years, respectively. The most common grade 3/4 adverse events and laboratory abnormalities were hematological disorders (neutropenia, 55.0 %; anemia; 10.0 % thrombocytopenia, 10.0 %), fatigue (10.0 %) and increased liver function tests (GGT, 10 %; ALT and AP, 5.0 % each). No febrile neutropenia was reported.

CONCLUSION

Lurbinectedin is an effective treatment for platinum-sensitive relapsed SCLC, especially in patients with CTFI ≥ 180 days, with acceptable safety and tolerability. These encouraging results suggest that lurbinectedin can be another valuable therapeutic option rather than platinum re-challenge.

Multicenter Phase II Study of Lurbinectedin in BRCA-Mutated and Unselected Metastatic Advanced Breast Cancer and Biomarker Assessment Substudy

PURPOSE

This multicenter phase II trial evaluated lurbinectedin (PM01183), a selective inhibitor of active transcription of protein-coding genes, in patients with metastatic breast cancer. A unicenter translational substudy assessed potential mechanisms of lurbinectedin resistance.

PATIENTS AND METHODS

Two arms were evaluated according to germline BRCA1/2 status: BRCA1/2 mutated (arm A; n = 54) and unselected ( BRCA1/2 wild-type or unknown status; arm B; n = 35). Lurbinectedin starting dose was a 7-mg flat dose and later, 3.5 mg/m² in arm A. The primary end point was objective response rate (ORR) per Response Evaluation Criteria in Solid Tumors (RECIST). The translational substudy of resistance mechanisms included exome sequencing (n = 13) and in vivo experiments with patient-derived xenografts (n = 11) from BRCA1/2-mutated tumors.

RESULTS

ORR was 41% (95% CI, 28% to 55%) in arm A and 9% (95% CI, 2% to 24%) in arm B. In arm A, median progression-free survival was 4.6 months (95% CI, 3.0 to 6.0 months), and median overall survival was 20.0 months (95% CI, 11.8 to 26.6 months). Patients with BRCA2 mutations showed an ORR of 61%, median progression-free survival of 5.9 months, and median overall survival of 26.6 months. The safety profile improved with lurbinectedin dose adjustment to body surface area. The most common nonhematologic adverse events seen at 3.5 mg/m² were nausea (74%; grade 3, 5%) and fatigue (74%; grade 3, 21%). Neutropenia was the most common severe hematologic adverse event (grade 3, 47%; grade 4, 10%). Exome sequencing showed mutations in genes related to the nucleotide excision repair pathway in four of seven tumors at primary or acquired resistance and in one patient with short-term stable disease. In vivo, sensitivity to cisplatin and lurbinectedin was evidenced in lurbinectedin-resistant (one of two) and cisplatin-resistant (two of three) patient-derived xenografts.

CONCLUSION

Lurbinectedin showed noteworthy activity in patients with BRCA1/2 mutations. Response and survival was notable in those with BRCA2 mutations. Additional clinical development in this subset of patients with metastatic breast cancer is warranted.

ATLANTIS: a Phase III study of lurbinectedin/doxorubicin versus topotecan or cyclophosphamide/doxorubicin/vincristine in patients with small-cell lung cancer who have failed one prior platinum-containing line

Lurbinectedin is an inhibitor of active transcription of protein-coding genes, causing DNA-break accumulation, apoptosis and modulation of the tumor microenvironment. Early-phase clinical trials indicate promising activity of lurbinectedin in small-cell lung cancer. Here, we describe the rationale and design of ATLANTIS (NCT02566993), an open-label, randomized, multicenter Phase III study to compare the efficacy of lurbinectedin and doxorubicin combination with standard-of-care chemotherapy, investigator's choice of cyclophosphamide/doxorubicin/vincristine or topotecan, in patients with small-cell lung cancer that has progressed following one line of platinum-based chemotherapy. Patients are randomized in a 1:1 ratio. The primary end point is overall survival and key secondary end points include progression-free survival, best tumor response and duration of response, each assessed by independent review committee.

Multicenter Phase II Study of Lurbinectedin in BRCA-Mutated and Unselected Metastatic Advanced Breast Cancer and Biomarker Assessment Substudy

Purpose

This multicenter phase II trial evaluated lurbinectedin (PM01183), a selective inhibitor of active transcription of protein-coding genes, in patients with metastatic breast cancer. A unicenter translational substudy assessed potential mechanisms of lurbinectedin resistance.

Patients and Methods

Two arms were evaluated according to germline BRCA1/2 status: BRCA1/2 mutated (arm A; n = 54) and unselected (BRCA1/2 wild-type or unknown status; arm B; n = 35). Lurbinectedin starting dose was a 7-mg flat dose and later, 3.5 mg/m² in arm A. The primary end point was objective response rate (ORR) per Response Evaluation Criteria in Solid Tumors (RECIST). The translational substudy of resistance mechanisms included exome sequencing (n = 13) and in vivo experiments with patient-derived xenografts (n = 11) from BRCA1/2-mutated tumors.

Results

ORR was 41% (95% CI, 28% to 55%) in arm A and 9% (95% CI, 2% to 24%) in arm B. In arm A, median progression-free survival was 4.6 months (95% CI, 3.0 to 6.0 months), and median overall survival was 20.0 months (95% CI, 11.8 to 26.6 months). Patients with BRCA2 mutations showed an ORR of 61%, median progression-free survival of 5.9 months, and median overall survival of 26.6 months. The safety profile improved with lurbinectedin dose adjustment to body surface area. The most common nonhematologic adverse events seen at 3.5 mg/m² were nausea (74%; grade 3, 5%) and fatigue (74%; grade 3, 21%). Neutropenia was the most common severe hematologic adverse event (grade 3, 47%; grade 4, 10%). Exome sequencing showed mutations in genes related to the nucleotide excision repair pathway in four of seven tumors at primary or acquired resistance and in one patient with short-term stable disease. In vivo, sensitivity to cisplatin and lurbinectedin was evidenced in lurbinectedin-resistant (one of two) and cisplatin-resistant (two of three) patient-derived xenografts.

Conclusion

Lurbinectedin showed noteworthy activity in patients with BRCA1/2 mutations. Response and survival was notable in those with BRCA2 mutations. Additional clinical development in this subset of patients with metastatic breast cancer is warranted.

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.

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.

Abstract P3-13-01: Lurbinectedin (PM01183) activity in BRCA1/2-associated or unselected metastatic breast cancer. Interim results of an ongoing phase II trial

Background: Metastatic breast cancer (MBC) is a clinically heterogeneous disease in which selective approaches are needed to identify patients (pts) who will benefit the most from available therapies and avoid unnecessary toxicities.

Lurbinectedin (PM01183) is a new anticancer drug that binds to the DNA minor groove inducing double-strand breaks and blocking transcription. It has significant in vitro and in vivo antitumor activity, particularly in breast cancer models. PM01183 is more active against homologous recombination-deficient cell lines. Hence, MBC pts with deleterious germline BRCA mutations might be more sensitive to PM01183 than those with sporadic tumors.

PM1183 activity was shown in different tumor types in clinical trials, especially in pts with platinum-resistant ovarian cancer (objective response rate [ORR]: 30%).

Methods: MBC pts &lt; 75-years-old with ductal or lobular carcinoma pretreated with ≤ 3 chemotherapy regimens for MBC, measurable disease per RECIST v1.1, performance status (PS) ≤1 and adequate major organ function are being treated with PM01183 7.0 mg flat dose i.v. every 3 weeks.

The primary aim is to evaluate the clinical efficacy of PM01183 in two cohorts of MBC pts: cohort A: BRCA+ (known germline BRCA1/2 mutation) and cohort B: unselected (BRCA1/2 wild type or unknown mutation status).

The primary endpoint is confirmed ORR by RECIST v1.1. A futility analysis was planned when 20 and 30 pts were recruited in cohort A and B, respectively. If at least 4 pts in cohort A and 3 pts in cohort B, achieve a response, recruitment in that cohort will continue up to 53 and 64 total pts, respectively.

Results: As of June 2014, 56 pts had been enrolled. Cohort A/B (n: 21/35): Median age 40/52-years-old; Cohort A(%)/B(%): PS 0: 48/66; &gt;2 metastatic sites: 58/40; most common sites of metastasis: lymph node 79/33, liver 48/60 and bone 42/48; triple negative: 57/46; hormonal receptor +: 38/49; prior anthracyclines: 95/91, taxanes: 100/94, platinum: 52/26, PARPi: 29/0; cohort A: BRCA 1/2 (%): 52/48.

Cohort A-BRCA 1/2+ (n=21)Cohort B-unselected (n=35)Median cycles (range)4 (1-20)3 (1-14)Best overall response(n= 17 evaluable)(n= 34 evaluable)CR1 (6%)0PR6 (35%)3 (9%)SD6 (35%)16 (47%)PD4 (24%)15 (44%)ORR (95%CI)41% (18-67%)9% (1.9-23.7%)Median duration of response Monts (95%CI)5.0 (0.1-12.8)3.3 (1.4-5.1)

In an exploratory analysis, ORR in cohort A was higher in PARPi naïve pts: 64% (7/11 pts).

Grade (G) 3-4 related adverse events occurred in &gt;5% pts were myelosuppression (neutropenia 69%, febrile neutropenia 7%, thrombocytopenia 14%); G3 fatigue 7%, transient transaminase increase 19% (G4: 2%), nausea 6% and dyspnea 6% (3 pts, 2 of them due to pneumonitis). One patient with massive liver involvement and impaired function died on C1D4 due to multiorgan failure possibly related to the study drug.

Conclusions: PM01183 has promising activity in pretreated MBC pts with BRCA mutation. Safety profile appears to be mostly predictable and with non-cumulative toxicity. Treatment-related neutropenia was manageable with G-CSF and/or dose reduction.

After futility analysis, targeted activity has been met in cohort A (BRCA+), and recruitment will continue up to 53 evaluable BRCA+ pts.

Citation Format: Judit Balmaña, Cristina Cruz, Judy Garber, Jose A Perez Fidalgo, Ana Lluch, Nadine Tung, Silvia Antolin, Cristian Fernandez, Carmen Kahatt, Sergio Szyldergemajn, Arturo Soto Matos, Sonia Extremera, Jose Baselga, Steven J Isakoff. Lurbinectedin (PM01183) activity in BRCA1/2-associated or unselected metastatic breast cancer. Interim results of an ongoing phase II trial [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P3-13-01.

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.

First-in-human phase I study of Lurbinectedin (PM01183) in patients with advanced solid tumors

PURPOSE

Lurbinectedin (PM01183) binds covalently to DNA and has broad activity against tumor cell lines. This first-in-human phase I study evaluated dose-limiting toxicities (DLT) and defined a phase II recommended dose for PM01183 as a 1-hour intravenous infusion every three weeks (q3wk).

EXPERIMENTAL DESIGN

Thirty-one patients with advanced solid tumors received escalating doses of PM01183 following an accelerated titration design.

RESULTS

PM01183 was safely escalated over 200-fold, from 0.02 to 5.0 mg/m(2). Dose doubling was utilized, requiring 15 patients and nine dose levels to identify DLT. The recommended dose was 4.0 mg/m(2), with one of 15 patients having DLT (grade 4 thrombocytopenia). Clearance was independent of body surface area; thus, a flat dose of 7.0 mg was used during expansion. Myelosuppression, mostly grade 4 neutropenia, occurred in 40% of patients but was transient and manageable, and none was febrile. All other toxicity was mild and fatigue, nausea and vomiting were the most common at the recommended dose. Pharmacokinetic parameters showed high interindividual variation, though linearity was observed. At or above the recommended dose, the myelosuppressive effect was significantly associated with the area under the concentration-time curve from time zero to infinity (white blood cells, P = 0.0007; absolute neutrophil count, P = 0.016). A partial response was observed in one patient with pancreatic adenocarcinoma at the recommended dose.

CONCLUSION

A flat dose of 7.0 mg is the recommended dose for PM01183 as a 1-hour infusion q3wk. This dose is tolerated and active. Severe neutropenia occurred at this dose, although it was transient and with no clinical consequences in this study.

Abstract OT1-4-01: Multicenter phase II trial of the novel compound PM01183 (P) in BRCA1/2-associated or unselected metastatic breast cancer (MBC)

Background: MBC is a clinically heterogeneous disease that cannot be cured with currently available treatment options. Selective approaches are needed to identify patient subgroups with different tumor sensitivities who will benefit the most from available therapies for MBC. PM01183 (P), also known as lurbinectedin, is a new anticancer drug that binds to the DNA minor groove inducing both double-strand breaks and transcription blocking. It has significant in vitro and in vivo activity against several tumor models, particularly breast cancer. P is more active against homologous recombination (HR)-deficient cell lines; hence, MBC patients (pts) with deleterious germline BRCA mutations might be more sensitive to P than sporadic tumors.

Methods: A multicenter, open-label, phase II study of P (7.0 mg fixed dose) as 1-hour intravenous infusion every 3 weeks in pts with MBC with or without known BRCA1/2 mutation at study entry. To be enrolled, pts must be women 18-75 years old with confirmed MBC pretreated with 1-3 chemotherapy regimens for MBC (including at least one prior trastuzumab-containing regimen for HER-2 overexpressing pts), measurable disease as per RECIST v1.1, performance status (PS) of 0-1 and adequate major organ function. Pts are excluded if pretreated with P, trabectedin, or radiotherapy (RT) on &gt;35% of bone marrow; if they have prior/concurrent malignant disease not in complete remission for &gt;5 years, clinically unstable central nervous system involvement, and other diseases/situations that might increase patient's risk; if they are pregnant or lactating women; or if they require RT.

Aims: The primary aim is to determine the antitumor activity of P, in terms of overall response rate (ORR), in two cohorts of MBC pts: BRCA+ (with known BRCA1/2 mutation), and unselected (with BRCA1/2 wild type or unknown mutation status). Secondary aims are to determine duration of response, clinical benefit (response or stable disease &gt; 3 months), PFS and one-year overall survival; to evaluate whether presence of BRCA1/2 mutation predicts response to P in MBC; to explore the activity of P in specific MBC subpopulations, safety, pharmacokinetics (PK), PK/pharmacodynamic correlations, and pharmacogenomics.

Planned enrollment is 117 evaluable pts: 53 in the BRCA+ cohort and 64 in the unselected cohort. P will be considered effective if confirmed objective response is achieved in ≥ 17 BRCA+ pts and ≥ 12 unselected patients. An ORR-based futility analysis will be conducted when 20 and 30 evaluable pts have been recruited in each cohort, respectively. If &lt;4 BRCA+ pts or &lt;3 unselected pts achieve response, recruitment into that cohort will be terminated. To date, 36 patients have been enrolled at 5 centers in 2 countries: 7 in the BRCA+ cohort and 29 in the unselected cohort. Additional sites are being recruited to participate.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr OT1-4-01.

Phase II study of weekly PM00104 (ZALYPSIS(®)) in patients with pretreated advanced/metastatic endometrial or cervical cancer

This open-label, two-arm, phase II clinical trial evaluated the antitumor activity and safety profile of PM00104 (Zalypsis(®)) administered as a 1-h, weekly, intravenous infusion (days 1, 8 and 15; every 4 weeks) at a dose of 2 mg/m(2) to patients with advanced and/or metastatic endometrial (EC) or cervical cancer (CC) after one previous line of systemic chemotherapy. Twelve patients (median age, 61.5 years) with pretreated EC received a median of 2 treatment cycles (range 1-5) and seven patients (median age, 38 years) with pretreated CC received 2 treatment cycles. None achieved objective tumor response. Median progression-free survival (PFS) was 1.8 months, and median overall survival (OS) was 5.5 months in EC (median follow-up = 20.1 months); median PFS was 1.5 months, and median OS was 5.6 months in CC (median follow-up = 17.1 months). The most common toxicities reported were mild to moderate asthenia, nausea, vomiting and diarrhea. Despite PM00104 showing mostly mild, predictable, manageable and reversible toxicity, protocol criteria for further recruitment were not met in EC, a futility analysis was done and recruitment was stopped; a low patient recruitment rate together with no evidence of activity in CC resulted in early study closure.