Background This randomised, double-blind study compared PF-05280014 (a trastuzumab biosimilar) with reference trastuzumab (Herceptin®) sourced from the European Union (trastuzumab-EU), when each was given with paclitaxel as first-line treatment for HER2-positive metastatic breast cancer. Methods Between 4 April 2014 and 22 January 2016, 707 participants were randomised 1:1 to receive intravenous PF-05280014 plus paclitaxel (PF-05280014 group; n = 352) or trastuzumab-EU plus paclitaxel (trastuzumab-EU group; n = 355). PF-05280014 or trastuzumab-EU was administered weekly (first dose 4 mg/kg, subsequent doses 2 mg/kg), with the option to change to a 3-weekly regimen (6 mg/kg) from Week 33. Treatment with PF-05280014 or trastuzumab-EU could continue until disease progression. Paclitaxel (starting dose 80 mg/m 2 ) was administered on Days 1, 8 and 15 of 28-day cycles for at least six cycles or until maximal benefit of response. The primary endpoint was objective response rate (ORR), evaluating responses achieved by Week 25 and confirmed by Week 33, based on blinded central radiology review. Results The risk ratio for ORR was 0.940 (95% CI: 0.842–1.049). The 95% CI fell within the pre-specified equivalence margin of 0.80–1.25. ORR was 62.5% (95% CI: 57.2–67.6%) in the PF-05280014 group and 66.5% (95% CI: 61.3–71.4%) in the trastuzumab-EU group. As of data cut-off on 11 January 2017 (using data up to 378 days post-randomisation), there were no notable differences between groups in progression-free survival (median: 12.16 months in the PF-05280014 group vs. 12.06 months in the trastuzumab-EU group; 1-year rate: 54% vs. 51%) or overall survival (median: not reached in either group; 1-year rate: 89.31% vs. 87.36%). Safety outcomes and immunogenicity were similar between the treatment groups. Conclusion When given as first-line treatment for HER2-positive metastatic breast cancer, PF-05280014 plus paclitaxel demonstrated equivalence to trastuzumab-EU plus paclitaxel in terms of ORR. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov, NCT01989676

PurposeThis study compared the pharmacokinetics of PF-06439535, a potential bevacizumab biosimilar, to bevacizumab sourced from the European Union (bevacizumab-EU) and USA (bevacizumab-US), and of bevacizumab-EU to bevacizumab-US.MethodsIn this double-blind study, 102 healthy males, aged 21–55 years, were randomized 1:1:1 to receive a single 5 mg/kg intravenous dose of PF-06439535, bevacizumab-EU, or bevacizumab-US. Pharmacokinetic assessments were conducted for 71 days, with additional safety and immunogenicity assessments until day 100. Pharmacokinetic similarity was achieved if 90 % confidence intervals (CIs) for the test-to-reference ratios of the maximum serum concentration (Cmax), area under the serum concentration–time curve from zero to infinity (AUC0–∞), and from zero to time of last quantifiable concentration (AUC0–t) were within the 80.00–125.00 % bioequivalence acceptance window.ResultsThe three study drugs exhibited similar pharmacokinetic properties. For the comparisons of PF-06439535 to bevacizumab-EU or bevacizumab-US, and of bevacizumab-EU to bevacizumab-US, the 90 % CIs for the ratios of Cmax, AUC0–t, and AUC0–∞ were all within 80.00–125.00 %. Two, one, and two subjects treated with PF-06439535, bevacizumab-EU, and bevacizumab-US, respectively, tested positive for antidrug antibodies, none of whom tested positive for neutralizing antibodies. Treatment-related adverse events were reported in 15.2, 25.7, and 18.2 % of subjects in the PF-06439535, bevacizumab-EU, and bevacizumab-US treatment arms, respectively.ConclusionsThis study demonstrated the pharmacokinetic similarity of PF-06439535 to both bevacizumab-EU and bevacizumab-US, and of bevacizumab-EU to bevacizumab-US. The safety profile (including immunogenicity) was similar in the three treatment groups, with no significant safety findings reported.Electronic supplementary materialThe online version of this article (doi:10.1007/s00280-016-3001-2) contains supplementary material, which is available to authorized users.

These results indicate that the MTD of BCNU when given in combination with O(6)-BG at a dose of 100 mg/m(2) is 40 mg/m(2) administered at 6-week intervals. This study provides the foundation for a phase II trial of O(6)-BG plus BCNU in nitrosourea-resistant malignant glioma.

BackgroundBiologic treatments for cancer continue to place a significant economic burden on healthcare stakeholders. Biosimilar therapies may help reduce this burden through cost savings, thereby increasing patient access.ObjectivesThe purpose of this study was to collate all published data to assess the weight of available evidence (quantity and quality) for proposed monoclonal antibody biosimilars and intended copies, for the treatment of cancer.MethodsMEDLINE®, Embase®, and ISI Web of Science® databases were searched to September 2015. Conference proceedings (17) were searched (2012 to July 2015). Searches of the United States National Library of Medicine ClinicalTrials.gov registry were also conducted. Risk of bias assessments were undertaken to assess data strength and validity.ResultsProposed biosimilars were identified in 23 studies (36 publications) in oncology and ten studies in 14 publications in oncology and chronic inflammatory diseases for bevacizumab, rituximab, and trastuzumab originators. Based on our review of the included published studies, and as inferred from the conclusions of study authors, the identified proposed biosimilars exhibit close similarity to their originators. Published data were also retrieved on intended copies of rituximab. It remains unclear what role these agents may have, as publications on rigorous clinical studies are lacking for these molecules.ConclusionWhile biosimilar products have the potential to improve patient access to important biologic therapies, robust evidence of outcomes for monoclonal antibody biosimilars in treating cancer patients, including data from comparative efficacy and safety trials, is not yet available in the published literature. Significant data gaps exist, particularly for intended copies, which reinforces the need to maintain a clear differentiation between these molecules and true biosimilars. As more biosimilars become available for use, it will be important for stakeholders to understand fully the robustness of overall evidence used to demonstrate biosimilarity and gain regulatory approval.Electronic supplementary materialThe online version of this article (doi:10.1007/s40259-016-0207-0) contains supplementary material, which is available to authorized users.

No abstract

Topoisomerase I (TopoI), an established anticancer target, is an enzyme producing a single-strand DNA break during transcription. Several noncamptothecin TopoI inhibitors have been identified. One of these, ARC-111, was compared with two clinically used camptothecins, topotecan and irinotecan/SN-38. In mouse and human bone marrow colony formation [colony-forming units granulocytemacrophage (CFU-GM)] assays, the IC 90 values were 519 and 331 nmol/L for topotecan and SN-38 mouse CFU-GM and were 19 and 26 nmol/L for human CFU-GM, giving mouse to human differentials of 28-and 13-fold. ARC-111 produced IC 90 values of 28 nmol/L in mouse and 6.2 nmol/L in human CFU-GM, thus only a 4.5-fold differential between species. Human bone marrow CFU-GM was more sensitive to topotecan than were several human cancer cell lines, but ARC-111 cytotoxicity was similar for human bone marrow CFU-GM and the seven human tumor cell lines tested. In HCT-116 xenografts, tumor growth delays (TGD) were 17 days for irinotecan and 20 days for ARC-111. In HT-29 xenografts, the TGD was 9 days for both irinotecan and ARC-111. Both ARC-111 and docetaxel had a TGD of 21 days in NCI-H460

Topoisomerase I inhibitors are a new class of anticancer agents with a mechanism of action aimed at interrupting DNA replication in cancer cells, the result of which is cell death. Most if not all Topoisomerase I inhibitors are derivatives of the plant extract camptothecin. Irinotecan (CPT‐11), a semi‐synthetic derivative of camptothecin, is approved in the United States for the treatment of colorectal cancer. Ongoing clinical trials with CPT‐11 show a 13% to 32% response rate when it is used singly or in combination with other chemotherapeutic agents such as 5‐fluorouracil. The major dose‐limiting toxicities of CPT‐11 are myelosuppression and a dual phase diarrhea. Topotecan is another semi‐synthetic analogue of camptothecin. It is approved for use in the United States for the treatment of cisplatin refractory ovarian carcinoma. Current clinical trials suggest antitumor activity against a variety of human tumor types. There is significant interindividual variability in the plasma disposition of this drug. The main dose‐limiting toxicity is myelosuppression. There are other derivatives of camptothecin, as well as new formulations of the parent plant extract, that are in various stages of clinical trials. Some of these clinical trials are aimed at increasing the therapeutic benefits of the agents when used singly or in combination with other chemotherapeutic agent(s) or treatment modalities. The dose‐limiting toxicity observed in most of these clinical trials is myelosuppression.

We recommend a dose of 130 to 160 mg/m(2), or 250 to 300 mg administered using the above weekly schedule for phase II studies. Further studies to characterize the pharmacodynamics and pharmacogenetics of TAS-103 are warranted.