Pembrolizumab versus methotrexate, docetaxel, or cetuximab in recurrent or metastatic head and neck squamous cell carcinoma (KEYNOTE-040): Subgroup analysis by pattern of disease recurrence.

BACKGROUND: In the phase 3 KEYNOTE-040 study, pembrolizumab prolonged OS versus chemotherapy in previously treated recurrent or metastatic (R/M) HNSCC. We present a post hoc subgroup analysis by disease recurrence pattern: recurrent-only, recurrent and metastatic (recurrent-metastatic), and metastatic-only HNSCC. MATERIALS AND METHODS: Patients had HNSCC that progressed during or after platinum-containing treatment for R/M disease or had recurrence or progression within 3-6 months of previous platinum-containing definitive therapy for locally advanced disease. Patients were randomly assigned (1:1) to pembrolizumab 200 mg Q3W or investigator's choice of standards of care (SOC): methotrexate, docetaxel, or cetuximab. Outcomes included OS, PFS, ORR, and DOR. The data cutoff was May 15, 2017. RESULTS: There were 125 patients (pembrolizumab, 53; SOC, 72) in the recurrent-only subgroup, 204 in the recurrent-metastatic subgroup (pembrolizumab, 108; SOC, 96), and 166 in the metastatic-only subgroup (pembrolizumab, 86; SOC, 80). The hazard ratio (95% CI) for death for pembrolizumab versus SOC was 0.83 (0.55-1.25) in the recurrent-only, 0.78 (0.58-1.06) in the recurrent-metastatic, and 0.74 (0.52-1.05) in the metastatic-only subgroups. PFS was similar between treatment arms in all subgroups. ORR was 22.6% for pembrolizumab versus 16.7% for SOC in the recurrent-only, 10.2% versus 6.3% in the recurrent-metastatic, and 15.1% versus 8.8% in the metastatic-only subgroups. DOR was numerically longer with pembrolizumab in all subgroups. CONCLUSION: Pembrolizumab provided numerically longer OS and durable responses in all subgroups compared with SOC, suggesting that patients with previously treated R/M HNSCC benefit from pembrolizumab regardless of recurrence pattern.

Pembrolizumab monotherapy versus chemotherapy in platinum-pretreated, recurrent or metastatic nasopharyngeal cancer (KEYNOTE-122): an open-label, randomized, phase III trial.

BACKGROUND: Pembrolizumab previously demonstrated robust antitumor activity and manageable safety in a phase Ib study of patients with heavily pretreated, programmed death ligand 1 (PD-L1)-positive, recurrent or metastatic nasopharyngeal carcinoma (NPC). The phase III KEYNOTE-122 study was conducted to further evaluate pembrolizumab versus chemotherapy in patients with platinum-pretreated, recurrent and/or metastatic NPC. Final analysis results are presented. PATIENTS AND METHODS: KEYNOTE-122 was an open-label, randomized study conducted at 29 sites, globally. Participants with platinum-pretreated recurrent and/or metastatic NPC were randomly assigned (1 : 1) to pembrolizumab or chemotherapy with capecitabine, gemcitabine, or docetaxel. Randomization was stratified by liver metastasis (present versus absent). The primary endpoint was overall survival (OS), analyzed in the intention-to-treat population using the stratified log-rank test (superiority threshold, one-sided P = 0.0187). Safety was assessed in the as-treated population. RESULTS: Between 5 May 2016 and 28 May 2018, 233 participants were randomly assigned to treatment (pembrolizumab, n = 117; chemotherapy, n = 116); Most participants (86.7%) received study treatment in the second-line or later setting. Median time from randomization to data cut-off (30 November 2020) was 45.1 months (interquartile range, 39.0-48.8 months). Median OS was 17.2 months [95% confidence interval (CI) 11.7-22.9 months] with pembrolizumab and 15.3 months (95% CI 10.9-18.1 months) with chemotherapy [hazard ratio, 0.90 (95% CI 0.67-1.19; P = 0.2262)]. Grade 3-5 treatment-related adverse events occurred in 12 of 116 participants (10.3%) with pembrolizumab and 49 of 112 participants (43.8%) with chemotherapy. Three treatment-related deaths occurred: 1 participant (0.9%) with pembrolizumab (pneumonitis) and 2 (1.8%) with chemotherapy (pneumonia, intracranial hemorrhage). CONCLUSION: Pembrolizumab did not significantly improve OS compared with chemotherapy in participants with platinum-pretreated recurrent and/or metastatic NPC but did have manageable safety and a lower incidence of treatment-related adverse events.

Pembrolizumab for locally advanced and recurrent/metastatic cutaneous squamous cell carcinoma (KEYNOTE-629 study): an open-label, nonrandomized, multicenter, phase II trial.

BACKGROUND: Pembrolizumab demonstrated clinically meaningful and durable antitumor activity with a manageable safety profile in recurrent/metastatic (R/M) cutaneous squamous cell carcinoma (cSCC). PATIENTS AND METHODS: KEYNOTE-629 was a global, open-label, nonrandomized, phase II trial of patients with locally advanced (LA) or R/M cSCC conducted at 59 centers. Eligible patients received intravenous pembrolizumab 200 mg every 3 weeks for up to 35 cycles. Primary endpoint was objective response rate (ORR), defined as the percentage of patients with a complete (CR) or partial response (PR), by blinded independent central review as per Response Evaluation Criteria in Solid Tumors 1.1. Secondary endpoints included duration of response (DOR), disease control rate, progression-free survival, overall survival, and safety and tolerability. Efficacy and safety were analyzed in patients who were treated with at least one dose of pembrolizumab. RESULTS: Between 29 November 2017 and 25 September 2019, 159 patients were enrolled and treated with pembrolizumab (LA cohort, n = 54; R/M cohort, n = 105). The median time from the first dose to data cut-off date (29 July 2020) was 14.9 [interquartile range (IQR), 12.6-17.2] months for the LA cohort and 27.2 (IQR, 25.6-29.2) months for the R/M cohort. In the LA cohort, ORR was 50.0% [95% confidence interval (CI), 36.1% to 63.9%], including 16.7% of patients with a CR and 33.3% with a PR. In the R/M cohort, ORR was 35.2% (95% CI, 26.2% to 45.2%), including 10.5% of patients with a CR and 24.8% with a PR. Median DOR was not reached in either cohort. Grade 3-5 treatment-related adverse events occurred in 11.9% of patients. CONCLUSIONS: The robust antitumor activity of pembrolizumab in both LA and R/M cSCC was confirmed and demonstrated to be durable without unexpected safety signals. Our findings establish pembrolizumab as a promising treatment option for cSCC.

Phase I-II study of vorinostat plus paclitaxel and bevacizumab in metastatic breast cancer: evidence for vorinostat-induced tubulin acetylation and Hsp90 inhibition in vivo.

In preclinical models, the histone deacetylase inhibitor vorinostat sensitizes breast cancer cells to tubulin-polymerizing agents and to anti-vascular endothelial growth factor-directed therapies. We sought to determine the safety and efficacy of vorinostat plus paclitaxel and bevacizumab as first-line therapy in metastatic breast cancer (MBC), and the biological effects of vorinostat in vivo. For this purpose of this study, 54 patients with measurable disease and no prior chemotherapy for MBC received vorinostat (200 or 300 mg PO BID) on days 1-3, 8-10, and 15-17, plus paclitaxel (90 mg/m(2)) on days 2, 9, 16, and bevacizumab (10 mg/kg) on days 2 and 16 every 28 days. The primary objective of the phase I study was to determine the recommended phase II dose (RPTD) of vorinostat, and for the phase II to detect an improvement of response rate from 40 to 60% (alpha = 0.10, beta = 0.10). No dose limiting toxicities were observed, and the RPTD of vorinostat was 300 mg BID. For the primary efficacy analysis in 44 patients at the RPTD, we observed 24 objective responses (55%, 95% confidence intervals (C.I) 39%, 70%). The adverse event profile was consistent with paclitaxel-bevacizumab, with the exception of increased diarrhea with the addition of vorinostat. Analysis of serial tumor biopsies in seven patients showed increased acetylation of Hsp90 and α-tubulin following vorinostat. Vorinostat induces histone and alpha tubulin acetylation and functional inhibition of Hsp90 in breast cancer in vivo and can be safely combined with paclitaxel and bevacizumab.

The role of genetic abnormalities of PTEN and the phosphatidylinositol 3-kinase pathway in breast and ovarian tumorigenesis, prognosis, and therapy.

Breast and ovarian cancers exhibit similar epidemiologic, genotypic, and phenotypic characteristics. Phosphatidylinositol 3-kinase (PI3K) and the PTEN tumor suppressor gene product phosphorylate and dephosphorylate the same 3' site in the inositol ring of membrane phosphatidylinositols. Germ-line mutations in the PTEN tumor suppressor gene are causative of Cowden's breast cancer predisposition syndrome, and PTEN is frequently mutated in sporadic breast cancers. In contrast, amplification of multiple components of the PI3K pathway is a hallmark of serous epithelial ovarian cancers. The resultant activation of the PI3K pathway in both breast and ovarian cancers contributes to cell-cycle progression, decreased apoptosis, and increased metastatic capabilities. Strikingly, both ovarian and breast cancer cells are selectively sensitive to pharmacologic and genetic manipulation of the PI3K pathway, making molecular therapeutics targeting this pathway particularly attractive approaches for these cancers.

Further characterization of the human cell multiprotein DNA replication complex.

Evidence for multiprotein complexes playing a role in DNA replication has been growing over the years. We have previously reported on a replication-competent multiprotein form of DNA polymerase isolated from human (HeLa) cell extracts. The proteins that were found at that time to co-purify with the human cell multiprotein form of DNA polymerase included: DNA polymerase alpha, DNA primase, topoisomerase I, RNase H, PCNA, and a DNA-dependent ATPase. The multiprotein form of the human cell DNA polymerase was further purified by Q-Sepharose chromatography followed by glycerol gradient sedimentation and was shown to be fully competent to support origin-specific and large T-antigen dependent simian virus 40 (SV40) DNA replication in vitro [Malkas et al. (1990b): Biochemistry 29:6362-6374]. In this report we describe the further characterization of the human cell replication-competent multiprotein form of DNA polymerase designated MRC. Several additional DNA replication proteins that co-purify with the MRC have been identified. These proteins include: DNA polymerase delta, RF-C, topoisomerase II, DNA ligase I, DNA helicase, and RP-A. The replication requirements, replication initiation kinetics, and the ability of the MRC to utilize minichromosome structures for DNA synthesis have been determined. We also report on the results of experiments to determine whether nucleotide metabolism enzymes co-purify with the human cell MRC. We recently proposed a model to represent the MRC that was isolated from murine cells [Wu et al. (1994): J Cell Biochem 54:32-46]. We can now extend this model to include the human cell MRC based on the fractionation, chromatographic and sedimentation behavior of the human cell DNA replication proteins. A full description of the model is discussed. Our experimental results provide further evidence to suggest that DNA synthesis is mediated by a multiprotein complex in mammalian cells.

Determination of lineage and clonality in diffuse lymphomas using the polymerase chain reaction technique.

Malignant lymphomas of the diffuse mixed or diffuse large cell subtype are immunologically heterogeneous and morphologic features do not allow prediction of lineage. Applications of immunophenotypic and gene rearrangement techniques has greatly improved our ability to determine clonality and lineage. Nevertheless, some diffuse lymphomas are composed of numerous reactive cells accompanying a small clonal population, thereby making determination of clonality difficult, even with gene rearrangement techniques. In this study, we report two malignant lymphomas in which immunophenotypic and genotypic studies failed to elucidate evidence of clonality. In both cases, the polymerase chain reaction amplified segments of DNA containing the bcl-2/JH sequence, providing evidence of clonality and suggesting B-cell lineage. We conclude that the polymerase chain reaction technique may be useful in the diagnosis of some diffuse mixed and large cell lymphomas.