Lurbinectedin as second- or third-line palliative therapy in malignant pleural mesothelioma: an international, multi-centre, single-arm, phase II trial (SAKK 17/16).

BACKGROUND: Systemic second- and third-line therapies for malignant pleural mesothelioma (MPM) result in a median progression-free survival (mPFS) of <2 months and median overall survival (mOS) of 6-9 months. Lurbinectedin binds to the DNA of the regulatory region while inhibiting tumour-associated macrophage transcription. In early trials, encouraging outcomes occurred in patients (pts) with MPM treated with lurbinectedin. We aimed to generate lurbinectedin efficacy and safety data among pts with progressive MPM. PATIENTS AND METHODS: Pts with progressing MPM treated with first-line platinum-pemetrexed chemotherapy with or without immunotherapy received lurbinectedin monotherapy. Treatment was given intravenously at 3.2 mg/m2 dose every 3 weeks until progression or unacceptable toxicity. Using Simon's two-stage design, the primary endpoint, progression-free survival (PFS) at 12 weeks (PFS12wks), was met if achieved by ≥21 pts (p0 ≤35% versus p1 ≥55%). RESULTS: Forty-two pts from nine centres across Switzerland and Italy were recruited. Histology was epithelioid in 33 cases, sarcomatoid in 5, and biphasic in 4. Overall 10/42 (23.8%) underwent prior immunotherapy and 14/42 (33.3%) had progressed ≤6 months after first-line chemotherapy. At data cut-off PFS12wks was met by 22/42 pts (52.4%; 90% confidence interval (CI): 38.7% to 63.5%; P = 0.015) with an mPFS of 4.1 months and mOS of 11.1 months. The best response was complete and partial remission observed in one patient each and stable disease in 20 pts. The duration of disease control was 6.6 months (95% CI: 5.2-7.4). No significant difference in PFS12wks, mPFS, and mOS was recorded in epithelioid versus non-epithelioid cases and pts with prior immunotherapy versus those without. Similar mPFS but shorter mOS were observed among pts who progressed within ≤6 months after first-line chemotherapy. Lurbinectedin-related grade 3-4 toxicity was seen in 21 pts, mostly being neutropenia (23.8%) and fatigue (16.7%). CONCLUSIONS: The primary efficacy endpoint was reached with acceptable toxicity. Lurbinectedin showed promising activity regardless of histology, prior immunotherapy, or outcome on prior treatment. CLINICALTRIALS. GOV IDENTIFIER: NCT03213301.

SAKK57/16 Nab-paclitaxel and Gemcitabine in Soft Tissue Sarcoma (NAPAGE): a phase I/II trial.

BACKGROUND: To determine whether the combination of nab-paclitaxel with gemcitabine has activity in patients with pretreated soft tissue sarcoma (STS). PATIENTS AND METHODS: NAPAGE is a phase Ib/II clinical trial investigating the combination of nab-paclitaxel (nab-pc) with gemcitabine employing two cohorts. One of a dose-de-escalation phase and one of expansion. In phase I, nab-pc was given at 150 mg/m2 in combination with gemcitabine 1000 mg/m2 every two weeks, until disease progression or unacceptable toxicity. This dose was recommended for phase II (RP2D), as there was no dose limiting toxicity (DLT) or discontinuations due to adverse events (AEs). The primary endpoint of the phase II was progression-free rate (PFR) at 3 months (H0: 20%, H1:40%). The secondary endpoints included progression free survival (PFS), overall survival (OS), AEs, objective response and patient-reported outcomes (PRO). Efficacy analysis was by intention to treat. RESULTS: The 3-month PFR was 56.4% (95% confidence interval CI: 39.6-72.2%). The 3-month and 6-month PFS were 58.4% (95% CI: 41.3-72.1%) and 44.6% (95% CI: 28.4-59.5%), respectively. Median PFS was 5.3 months (95% CI: 1.4-8.2) and median OS was 12.8 months (95% CI: 10.5-39.2). The most common treatment-related grade ≥ 3 AE were neutropenia (18%), followed by anemia (2.6%), hypertension (2.6%) and alanine aminotransferase increase (2.6%). Grade 1 and grade 2 peripheral sensory neuropathy (PNP) occurred in 15.4% and 20.5%, respectively. No grade 3-4 PNP was reported. CONCLUSIONS: Combining nab-pc and gemcitabine is safe. Promising activity is observed in pretreated STS patients with manageable toxicity. This regimen should be considered for further exploration.

Off-label despite high-level evidence: a clinical practice review of commonly used off-patent cancer medicines.

INTRODUCTION: Off-label use of medicines is generally discouraged. However, several off-patent, low-cost cancer medicines remain off-label for indications in which they are commonly used in daily practice, supported by high-level evidence based on results of phase III clinical trials. This discrepancy may generate prescription and reimbursement obstacles as well as impaired access to established therapies. METHODS: A list of cancer medicines that remain off-label in specific indications despite the presence of high-level evidence was generated and subjected to European Society for Medical Oncology (ESMO) expert peer review to assess for accountability of reasonableness. These medicines were then surveyed on approval procedures and workflow impact. The most illustrative examples of these medicines were reviewed by experts from the European Medicines Agency to ascertain the apparent robustness of the supporting phase III trial evidence from a regulatory perspective. RESULTS: A total of 47 ESMO experts reviewed 17 cancer medicines commonly used off-label in six disease groups. Overall, high levels of agreement were recorded on the off-label status and the high quality of data supporting the efficacy in the off-label indications, often achieving high ESMO-Magnitude of Clinical Benefit Scale (ESMO-MCBS) scores. When prescribing these medicines, 51% of the reviewers had to implement a time-consuming process associated with additional workload, in the presence of litigation risks and patient anxiety. Finally, the informal regulatory expert review identified only 2 out of 18 (11%) studies with significant limitations that would be difficult to overcome in the context of a potential marketing authorisation application without additional studies. CONCLUSIONS: We highlight the common use of off-patent essential cancer medicines in indications that remain off-label despite solid supporting data as well as generate evidence on the adverse impact on patient access and clinic workflows. In the current regulatory framework, incentives to promote the extension of indications of off-patent cancer medicines are needed for all stakeholders.

Long-term benefit of lurbinectedin as palliative chemotherapy in progressive malignant pleural mesothelioma (MPM): final efficacy and translational data of the SAKK 17/16 study.

BACKGROUND: The SAKK 17/16 study showed promising efficacy data with lurbinectedin as second- or third-line palliative therapy in malignant pleural mesothelioma. Here, we evaluated long-term outcome and analyzed the impact of lurbinectedin monotherapy on the tumor microenvironment at the cellular and molecular level to predict outcomes. MATERIAL AND METHODS: Forty-two patients were treated with lurbinectedin in this single-arm study. Twenty-nine samples were available at baseline, and seven additional matched samples at day one of cycle two of treatment. Survival curves and rates between groups were compared using the log-rank test and Kaplan-Meier method. Statistical significance was set at P value <0.05. RESULTS: Updated median overall survival (OS) was slightly increased to 11.5 months [95% confidence interval (CI) 8.8-13.8 months]. Thirty-six patients (85%) had died. The OS rate at 12 and 18 months was 47% (95% CI 32.1% to 61.6%) and 31% (95% CI 17.8% to 45.0%), respectively. Median progression-free survival was 4.1 months (95% CI 2.6-5.5 months). No new safety signals were observed. Patients with lower frequencies of regulatory T cells, as well as lower tumor-associated macrophages (TAMs) at baseline, had a better OS. Comparing matched biopsies, a decrease of M2 macrophages was observed in five out of seven patients after exposure to lurbinectedin, and two out of four patients showed increased CD8+ T-cell infiltrates in tumor. DISCUSSION: Lurbinectedin continues to be active in patients with progressing malignant pleural mesothelioma. According to our very small sample size, we hypothesize that baseline TAMs and regulatory T cells are associated with survival. Lurbinectedin seems to inhibit conversion of TAMs to M2 phenotype in humans.

CT60 single-nucleotide polymorphism as a surrogate marker for donor lymphocyte infusion outcome after allogeneic cell transplantation for acute leukemia.

The benefit of survival at the expense of new GVHD after DLI for acute leukemia following human allogeneic hematopoietic cell transplantation (allo-HCT) remains a matter of controversy. The detection of biological markers predicting this outcome would be an enormous breakthrough. The purpose of this study was the analysis of CT60 single-nucleotide polymorphism (SNP) of the CTLA-4 T-regulatory gene as a surrogate marker for DLI outcome in this difficult setting. Using Pyrosequencing, we genotyped the alleles of the CT60 SNP of 79 DLI donors and correlated them with the post-DLI outcome of their matching recipients. The presence of a donor 'AA' or 'AG' CT60 genotype vs a 'GG' genotype was an independent factor for remaining in complete chimerism/remission post-DLI (odds ratio (OR) 2.61 vs 0.42, respectively, P=0.05). Further, in cases with evident post-DLI allo-reactivity the importance of an 'AA' or 'AG' vs a 'GG' genotype gained significance for ongoing complete chimerism (OR 4.35 vs 0.32, P=0.03). Neither alterations in cumulative DLI dose nor any other clinical parameter significantly weakened the importance of CT60 SNP. Our results provide evidence for the necessity of genotyping CT60 SNP prior to DLI administration in patients with acute leukemia.