Comparison of three-weekly and six-weekly pembrolizumab United Kingdom prescribing practice for advanced and resected melanoma.

BACKGROUND: Pembrolizumab is approved for the treatment of advanced and resected melanoma and was originally licensed as a three-weekly infusion (Q3W). In April 2019, a six-weekly infusion schedule (Q6W) was also approved. We retrospectively reviewed pembrolizumab prescribing for patients with melanoma across multiple United Kingdom (UK) centres to compare the safety and efficacy of Q6W with Q3W in real-world clinical practice. METHODS: Case notes for melanoma patients treated with pembrolizumab between April 2019 and August 2020 at eight UK centres were reviewed. Prespecified baseline characteristics of the Q3W and Q6W cohorts were compared, as well as toxicity and efficacy outcomes. Prescribers were surveyed about their prescribing practice. RESULTS: Two hundred seventy-seven patients were included: 116 commenced Q3W and 161 commenced Q6W pembrolizumab. The proportion of Q6W prescriptions varied by the centre (range 32-88%). Patient factors associated with an increased likelihood of receiving Q3W over Q6W were preexisting autoimmune comorbidity (odds ratio [OR] 0.33; 95% confidence interval [CI] 0.12-0.82) and treatment for advanced (versus resected) disease (OR 0.54; 95%CI 0.33-0.90). Toxicity outcomes were broadly similar for Q6W and Q3W: 14.9% versus 15.5% ≥ grade 3 Common Terminology Criteria for Adverse Events. Estimated 12-month recurrence-free survival for adjuvantly treated patients was 78.9% for Q6W and 74.2% for Q3W (hazard ratio [HR] 0.93; 95%CI 0.50-1.73). Estimated 12-month progression-free survival for advanced patients was 41.8% for Q6W and 55.9% for Q3W (HR 1.21, 95%CI 0.67-2.18). CONCLUSIONS: Q6W is an appropriate option for administering pembrolizumab, given the opportunity to reduce the health service resource burden.

Achieving optimal dose intensity with adjuvant chemotherapy in elderly breast cancer patients: a 10-year retrospective study in a UK institution.

The study was to determine if breast cancer patients aged 65 and above could be given adjuvant chemotherapy safely while achieving an acceptable relative dose intensity of at least 85%. We identified all patients aged 65 and over who received adjuvant chemotherapy over the 10 year period, November 1999 to October 2009, and determined the proportion that achieved a relative dose intensity of at least 85% as well as the tolerability of their treatment. A total of 101 patients were identified, with a median age of 69 years (range 65-78).Of these, 25.7% of patients had at least one major comorbidity, 84.2% had a tumor size of 5 cm or less, 73.3% were node positive and 58.4% were hormone receptor positive. The chemotherapy regimens used were AC (Doxorubicin and Cyclophosphamide), FEC (Fluorouracil, Epirubicin, and Cyclophosphamide), CMF (Cyclophosphamide, Methotrexate, and Fluorouracil) and ECMF (Epirubicin followed by CMF). Seventy-nine patients (78.2%) achieved the relative dose intensity of at least 85%. With respect to toxicity, 11.9% of patients developed febrile neutropenia and 23.8% of patients required hospital admission during the treatment period, but there were no treatment-related deaths in the group. A significant proportion of patients aged 65 and above achieved the intended dose intensity of at least 85% over this 10-year period, with manageable toxicity levels. This supports the use of these regimens as adjuvant chemotherapy for breast cancer in this age group.

Chemotherapy-induced CXC-chemokine/CXC-chemokine receptor signaling in metastatic prostate cancer cells confers resistance to oxaliplatin through potentiation of nuclear factor-kappaB transcription and evasion of apoptosis.

Constitutive activation of nuclear factor (NF)-kappaB is linked with the intrinsic resistance of androgen-independent prostate cancer (AIPC) to cytotoxic chemotherapy. Interleukin-8 (CXCL8) is a transcriptional target of NF-kappaB whose expression is elevated in AIPC. This study sought to determine the significance of CXCL8 signaling in regulating the response of AIPC cells to oxaliplatin, a drug whose activity is reportedly sensitive to NF-kappaB activity. Administration of oxaliplatin to PC3 and DU145 cells increased NF-kappaB activity, promoting antiapoptotic gene transcription. In addition, oxaliplatin increased the transcription and secretion of CXCL8 and the related CXC-chemokine CXCL1 and increased the transcription and expression of CXC-chemokine receptors, especially CXC-chemokine receptor (CXCR) 2, which transduces the biological effects of CXCL8 and CXCL1. Stimulation of AIPC cells with CXCL8 potentiated NF-kappaB activation in AIPC cells, increasing the transcription and expression of NF-kappaB-regulated antiapoptotic genes of the Bcl-2 and IAP families. Coadministration of a CXCR2-selective antagonist, AZ10397767 (Bioorg Med Chem Lett 18:798-803, 2008), attenuated oxaliplatin-induced NF-kappaB activation, increased oxaliplatin cytotoxicity, and potentiated oxaliplatin-induced apoptosis in AIPC cells. Pharmacological inhibition of NF-kappaBorRNA interference-mediated suppression of Bcl-2 and survivin was also shown to sensitize AIPC cells to oxaliplatin. Our results further support NF-kappaB activity as an important determinant of cancer cell sensitivity to oxaliplatin and identify the induction of autocrine CXCR2 signaling as a novel mode of resistance to this drug.