Phase I/II study to assess the clinical pharmacology and safety of single ascending and multiple subcutaneous doses of PF-06881894 in women with non-distantly metastatic breast cancer.

PURPOSE: To evaluate the pharmacodynamics (PD), pharmacokinetics (PK), and safety of single and multiple doses of PF-06881894 (pegfilgrastim-apgf; Nyvepria™), a biosimilar to reference pegfilgrastim (Neulasta®), in women with non-distantly metastatic breast cancer. METHODS: In Phase I (Cycle 0) of this Phase I/II study, the PD response (absolute neutrophil count [ANC]; CD34 + count), PK profile, and safety of a single 3- or 6-mg subcutaneous dose of PF-06881894 were assessed in chemotherapy-naïve patients before definitive breast surgery. In Phase II (Cycles 1-4), the PD response (duration of severe neutropenia [DSN, Cycle 1], ANC [Cycles 1 and 4]) and PK profile (Cycles 1 and 4) of single and multiple 6-mg doses of PF-06881894 concomitant with chemotherapy and after definitive breast surgery were assessed. RESULTS: Twenty-five patients (mean age 59 years) were enrolled (Cycle 0, n = 12; Cycles 1-4, n = 13). In Cycle 0, PD responses and PK values were lower with 3-mg versus 6-mg PF-06881894. In Cycles 1 and 4, mean DSN was 0.667 days after single or multiple 6-mg doses of PF-06881894, respectively. In Cycle 4 versus Cycle 1, PD responses were more robust; PK values (mean area under the curve, maximum concentration) were lower; and clearance values were higher. The safety profile of PF-06881894 was similar to that for reference pegfilgrastim. CONCLUSION: PF-06881894 as a single 3- or 6-mg dose prior to definitive surgery, or multiple 6-mg/cycle doses postoperatively, with/without myelosuppressive chemotherapy, was consistent with the clinical pharmacology and safety profile of reference pegfilgrastim. TRIAL REGISTRATION: October 2017. ClinicalTrials.gov Identifier: NCT02650193. EudraCT Number: 2015-002057-35.

PF-05280014 (a trastuzumab biosimilar) plus paclitaxel compared with reference trastuzumab plus paclitaxel for HER2-positive metastatic breast cancer: a randomised, double-blind study.

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/m2) 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.

Evaluating imbalances of adverse events during biosimilar development.

Biosimilars are designed to be highly similar to approved or licensed (reference) biologics and are evaluated based on the totality of evidence from extensive analytical, nonclinical and clinical studies. As part of the stepwise approach recommended by regulatory agencies, the first step in the clinical evaluation of biosimilarity is to conduct a pharmacokinetics similarity study in which the potential biosimilar is compared with the reference product. In the context of biosimilar development, a pharmacokinetics similarity study is not necessarily designed for a comparative assessment of safety. Development of PF-05280014, a potential biosimilar to trastuzumab, illustrates how a numerical imbalance in an adverse event in a small pharmacokinetics study can raise questions on safety that may require additional clinical trials.

Neratinib, an irreversible pan-ErbB receptor tyrosine kinase inhibitor: results of a phase II trial in patients with advanced non-small-cell lung cancer.

PURPOSE: Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have had a significant impact on non-small-cell lung cancer (NSCLC) outcomes, particularly for patients with EGFR mutations. Resistance emerges after 9 to 12 months, primarily mediated by the T790M resistance mutation. We studied neratinib, an irreversible pan-ErbB TKI that may overcome T790M. PATIENTS AND METHODS: Patients with advanced NSCLC underwent EGFR sequencing of available tumor tissue at enrollment. Those with > or = 12 weeks of prior TKI therapy were placed in arm A if they were EGFR mutation positive or arm B if they were wild-type. Arm C included TKI-naïve patients with adenocarcinoma and light smoking histories (< or = 20 pack-years). All patients received daily oral neratinib, initially at 320 mg but subsequently reduced to 240 mg because of excessive diarrhea. The primary end point was objective response rate (RR). RESULTS: One-hundred sixty-seven patients were treated: 91 in arm A, 48 in arm B, and 28 in arm C. Diarrhea was the most common toxicity; grade 3 incidence was 50% at 320 mg but improved to 25% after dose reduction. The RR was 3% in arm A and zero in arms B and C. No patients with known T790M responded. Notably, three of four patients with an exon 18 G719X EGFR mutation had a partial response and the fourth had stable disease lasting 40 weeks. CONCLUSION: Neratinib had low activity in patients with prior benefit from TKIs and in TKI-naïve patients, potentially because of insufficient bioavailability from diarrhea-imposed dose limitation. Responses were seen in patients with the rare G719X EGFR mutation, highlighting the importance of obtaining comprehensive genetic information on trials of targeted agents.