Gemcitabine in the treatment of advanced head and neck cancer

Cytosolic 5'-Nucleotidase III and Nucleoside Triphosphate Diphosphohydrolase 1 Dephosphorylate the Pharmacologically Active Metabolites of Gemcitabine and Emtricitabine

Gemcitabine (dFdC) and emtricitabine (FTC) are first-line drugs that are used for the treatment of pancreatic cancer and human immunodeficiency virus, respectively. The above drugs must undergo sequential phosphorylation to become pharmacologically active. Interindividual variability associated with the responses of the above drugs has been reported. The molecular mechanisms underlying the observed variability are yet to be elucidated. Although this could be multifactorial, nucleotidases may be involved in the dephosphorylation of drug metabolites due to their structural similarity to endogenous nucleosides. With these in mind, we performed in vitro assays using recombinant nucleotidases to assess their enzymatic activities toward the metabolites of dFdC and FTC. From the above in vitro experiments, we noticed the dephosphorylation of dFdC-monophosphate in the presence of two 5'-nucleotidases (5'-NTs), cytosolic 5'-nucleotidase IA (NT5C1A) and cytosolic 5'-nucleotidase III (NT5C3), individually. Interestingly, FTC monophosphate was dephosphorylated only in the presence of NT5C3 enzyme. Additionally, nucleoside triphosphate diphosphohydrolase 1 (NTPDase 1) exhibited enzymatic activity toward both triphosphate metabolites of dFdC and FTC. Enzyme kinetic analysis further revealed Michaelis-Menten kinetics for both NT5C3-mediated dephosphorylation of monophosphate metabolites, as well as NTPDase 1-mediated dephosphorylation of triphosphate metabolites. Immunoblotting results confirmed the presence of NT5C3 and NTPDase 1 in both pancreatic and colorectal tissue that are target sites for dFdC and FTC treatment, respectively. Furthermore, sex-specific expression patterns of NT5C3 and NTPDase 1 were determined using mass spectrometry-based proteomics approach. Based on the above results, NT5C3 and NTPDase 1 may function in the control of the levels of dFdC and FTC metabolites. SIGNIFICANCE STATEMENT: Emtricitabine and gemcitabine are commonly used drugs for the treatment of human immunodeficiency virus and pancreatic cancer. To become pharmacologically active, both the above drugs must be phosphorylated. The variability in the responses of the above drugs can lead to poor clinical outcomes. Although the sources of drug metabolite concentration variability are multifactorial, it is vital to understand the role of nucleotidases in the tissue disposition of the above drug metabolites due to their structural similarities to endogenous nucleosides.

Clinical Trial Development in TP53-Mutated Locally Advanced and Recurrent and/or Metastatic Head and Neck Squamous Cell Carcinoma

TP53 mutation is the most frequent genetic event in head and neck squamous cell carcinoma (HNSCC), found in more than 80% of patients with human papillomavirus-negative disease. As mutations in the TP53 gene are associated with worse outcomes in HNSCC, novel therapeutic approaches are needed for patients with TP53-mutated tumors. The National Cancer Institute sponsored a Clinical Trials Planning Meeting to address the issues of identifying and developing clinical trials for patients with TP53 mutations. Subcommittees, or breakout groups, were tasked with developing clinical studies in both the locally advanced and recurrent and/or metastatic (R/M) disease settings as well as considering signal-seeking trial designs. A fourth breakout group was focused on identifying and standardizing biomarker integration into trial design; this information was provided to the other breakout groups prior to the meeting to aid in study development. A total of 4 concepts were prioritized to move forward for further development and implementation. This article summarizes the proceedings of the Clinical Trials Planning Meeting with the goal of developing clinical trials for patients with TP53-mutant HNSCC that can be conducted within the National Clinical Trials Network.

The Role of the Microbiome in Oral Squamous Cell Carcinoma with Insight into the Microbiome-Treatment Axis

Oral squamous cell carcinoma (OSCC) is one of the leading presentations of head and neck cancer (HNC). The first part of this review will describe the highlights of the oral microbiome in health and normal development while demonstrating how both the oral and gut microbiome can map OSCC development, progression, treatment and the potential side effects associated with its management. We then scope the dynamics of the various microorganisms of the oral cavity, including bacteria, mycoplasma, fungi, archaea and viruses, and describe the characteristic roles they may play in OSCC development. We also highlight how the human immunodeficiency viruses (HIV) may impinge on the host microbiome and increase the burden of oral premalignant lesions and OSCC in patients with HIV. Finally, we summarise current insights into the microbiome–treatment axis pertaining to OSCC, and show how the microbiome is affected by radiotherapy, chemotherapy, immunotherapy and also how these therapies are affected by the state of the microbiome, potentially determining the success or failure of some of these treatments.

HPMA-based polymeric conjugates in anticancer therapeutics

Polymer therapeutics has gained prominence due to an attractive structural polymer chemistry and its applications in diseases therapy. In this review, we discussed the development and capabilities of N-(2-hydroxypropyl) methacrylamide (HPMA) and HPMA-drug conjugates in cancer therapy. The design, architecture, and structural properties of HPMA make it a versatile system for the synthesis of polymeric conjugations for biomedical applications. Research suggests that HPMA could be a possible alternative for polymers such polyethylene glycol (PEG) in biomedical applications. Although numerous clinical trials of HPMA-drug conjugates are ongoing, yet no product has been successfully brought to the market. Thus, further research is required to develop HPMA-drug conjugates as successful cancer therapeutics.

Chemotherapy after immune checkpoint blockade in patients with recurrent, metastatic squamous cell carcinoma of the head and neck

OBJECTIVES

Given that immune checkpoint inhibitors (ICIs) are now preferred agents in first-line treatment of recurrent/metastatic (R/M) squamous cell carcinoma of the head and neck (SCCHN), we retrospectively studied outcomes on post-ICI therapies.

MATERIALS AND METHODS

We collected data from the medical records of 60 patients with R/M SCCHN who received ICIs followed by at least one further line of cytotoxic or biologic therapy at our institution from 2014 to 2019. We also compared outcomes with those of historical trials in the ICI-naïve, second-line or greater setting.

RESULTS

Patients who received platinum-based regimens as their post-ICI therapies experienced improved overall response (ORR) (50% versus 10%, p < 0.01) and improved overall survival (OS) (15.1 months versus 7.3 months, HR 0.46, p = 0.04) compared to the rest of the cohort. Patients receiving platinum re-challenge were more likely to respond than all other patients in the cohort (OR 8.37, p = 0.01). The ORR for patients on 5-fluorouracil (5-FU)-containing regimens (63%) was also higher than other patients in the cohort (p = 0.03). Immunotherapy-based regimens compared favorably to historical data of first exposure to ICIs (disease control rate 54% versus 36%). Singlet regimens were associated with shorter OS than other regimens (HR = 2.38, p = 0.01).

CONCLUSIONS

Platinum- and 5-FU-based doublet or triplet regimens may be superior options in the post-ICI setting. Immunotherapy re-challenge following ICI therapy may also be a reasonable option.

Overcoming the delivery barrier of oligonucleotide drugs and enhancing nucleoside drug efficiency: The use of nucleolipids

With the rapid development of synthetic technology and biological technology, many nucleic acid-based drugs have entered the clinical trials. However, their inherent disabilities in actively and efficiently penetrating cell membranes still severely restrict their further application. The main drawback of cationic lipids, which have been widely used as nonviral vectors of nucleic acids, is their high cytotoxicity. A series of nucleoside-based or nucleotide-based nucleolipids have been reported in recent years, due to their oligonucleotide delivery capacity and low toxicity in comparison with cationic lipids. Lipophilic prodrugs of nucleoside analogs have extremely similar structures with nucleolipid vectors and are thus helpful for improving the transmembrane ability. This review introduces the progress of nucleolipids and provides new strategies for improving the delivery efficiency of nucleic acid-based drugs, as well as lipophilic prodrugs of nucleosides or nucleotides for antiviral or anticancer therapies.

Gemcitabine-Based Chemoradiation in the Treatment of Locally Advanced Head and Neck Cancer: Systematic Review of Literature and Meta-Analysis

BACKGROUND

Platinum-based concurrent chemoradiation (CCRT) improves locoregional control and overall survival of locoregionally advanced (LA) squamous cell carcinoma of the head and neck (SCCHN) when compared to radiotherapy alone, but this approach is hampered by significant toxicity. Therefore, alternative ways to enhance the radiation effects are worth investigating. Gemcitabine (2',2'-difluorodeoxycytidine), in addition to its activity against a variety of solid tumors, including SCCHN, is one of the most potent radiosensitizers, and it has an overall favorable safety profile. In this paper, the clinical experience with gemcitabine-based chemoradiation in the treatment of patients with LA-SCCHN is reviewed.

METHODS

We conducted a review of the literature on the clinical experience with radiotherapy combined with either single-agent gemcitabine or gemcitabine/cisplatin-based polychemotherapy for the treatment of patients with LA-SCCHN. We also searched abstracts in databases of major international oncology meetings from the last 20 years. A meta-analysis was performed to calculate pooled proportions with 95% confidence intervals (CIs) for complete response rate and grade 3-4 acute mucositis rate.

RESULTS

A total of 13 papers were eligible for the literature review. For schedules using a gemcitabine dose intensity (DI) below 50 mg/m(2) per week, the complete response rate was 86% (95% CI, 74%-93%) with grade 3-4 acute mucositis rate of 38% (95% CI, 27%-50%) and acceptable late toxicity. In one of the studies employing such low DIs, survival data were provided showing a 3-year overall survival of 50%. Compared with DI ≥50 mg/m(2) per week, there was no difference in the complete response rate (71%; 95% CI, 55%-83%; p = .087) but a significantly higher (p < .001) grade 3-4 acute mucositis rate of 74% (95% CI, 62%-83%), often leading to treatment interruptions (survival data provided in 8 studies; 3-year overall survival, 27%-63%). Late toxicity comprising mainly dysphagia was generally underreported, whereas information about xerostomia and skin fibrosis was scarce.

CONCLUSION

This review highlights the radiosensitizing potential of gemcitabine and suggests that even very low dosages (less than 50 mg/m(2) per week) provide a sufficient therapeutic ratio and therefore should be further investigated. Refinements in radiation schemes, including intensity-modulated radiation therapy, in combination with low-dose gemcitabine and targeted agents, such as cetuximab, are currently being investigated.

IMPLICATIONS FOR PRACTICE

Cisplatin-based concurrent chemoradiation (CCRT) has become the standard treatment of locally advanced head and neck cancer (LAHNC). This approach is hampered by significant toxicity. This paper reviews the studies using gemcitabine as an alternative radio-sensitizer for CCRT in patients with LAHNC. In this capacity, despite its mild intrinsic toxicity, gemcitabine comes with high rates of severe mucositis when used in dosages exceeding 50 mg/m(2) per week. CCRT with low-dose gemcitabine provides a sufficient therapeutic ratio, combining clinical activity, similar to the higher-dose regimens, with lower toxicity. Further investigation is warranted.

Molecular profiling of head and neck squamous cell carcinoma

Background

Head and neck squamous cell carcinoma (HNSCC) exhibits high rates of recurrence, and with few approved targeted agents, novel treatments are needed. We analyzed a molecular profiling database for the distribution of biomarkers predictive of chemotherapies and targeted agents.

Methods

Seven hundred thirty‐five patients with advanced HNSCC (88 with known human papillomavirus [HPV] status), were profiled using multiple platforms (gene sequencing, gene copy number, and protein expression).

Results

Among the entire patient population studied, epidermal growth factor receptor (EGFR) was the protein most often overexpressed (90%), TP53 gene most often mutated (41%), and phosphatidylinositol 3‐kinase (PIK3CA) most often amplified (40%; n = 5). With the exception of TP53 mutation, other biomarker frequencies were not significantly different among HPV‐positive or HPV‐negative patients. PIK3CA mutations and phosphatase and tensin homolog (PTEN) loss are frequent events, independent of HPV status. The immune response‐modulating programmed cell death 1 (PD1) and programmed cell death ligand 1 (PDL1) axis was active across sites, stages, and HPV status.

Conclusion

Molecular profiling utilizing multiple platforms provides a range of therapy options beyond standard of care. © 2015 Wiley Periodicals, Inc. Head Neck38: E1625–E1638, 2016

Biweekly gemcitabine and paclitaxel in patients with relapsed or metastatic squamous cell carcinoma of the head and neck

Purpose:

We conducted a Phase II, clinical trial to evaluate the efficacy and safety of a biweekly gemcitabine and paclitaxel (GEMTAX) regimen as second-line treatment in patients with recurrent or metastatic unresectable, squamous cell carcinoma of the head and neck (SCCHN). The primary endpoint was response rate.

Patients and Methods:

Patients with recurrent unresectable or metastatic platinum refractory SCCHN, who had performance status ≤2 and adequate organ function, were eligible. Gemcitabine (3000 mg/m² intravenous) and paclitaxel (150 mg/m² intravenous) was given on days 1 and 15of 4 weeks cycle, until patients had disease progression or unacceptable toxicity.

Results:

Disease control (partial response [PR] + complete response [CR] + stable disease [SD]) was noted in 19 patients (54%) and overall response (CR + PR) was noted in 8 patients (23%). However, the most frequent response outcomes were progressive disease in 16 patients (46%) and SD in 11 patients (31%). The most frequent Grade 3–4 adverse events were lymphopenia in 38 patients (75%), anemia in 20 patients (39%), and infection in 16 patients (31%). Median progression-free survival was 3.6 months; median overall survival was 6.3 months.

Conclusion:

The biweekly GEMTAX regimen has statistically significant grade 3 and 4 adverse events and has meaningful clinical activity as a second-line treatment in patients with recurrent or metastatic SCCHN who have received prior chemotherapy. This regimen may particularly be a useful treatment option in patients who progressed in less than 6 months of concurrent chemoradiotherapy with high-dose cisplatin and/or have recurrent/metastatic platinum refractory SCCHN.

Phase II trial of biweekly gemcitabine and paclitaxel with recurrent or metastatic squamous cell carcinoma of the head and neck: Southwest Oncology Group study S0329

BACKGROUND

A phase I study and an institutional pilot study in patients with metastatic/recurrent squamous cell carcinoma of the head and neck (SCCHN) utilizing biweekly gemcitabine and paclitaxel (GEMTAX), showed an overall response rate of 53%. 1 This phase II trial was conducted to determine the feasibility, tolerability, and efficacy of this combination.

METHODS

Patients with metastatic/recurrent SCCHN were treated with gemcitabine (3000 mg/m2) and paclitaxel (150 mg/m2) on days 1 and 15 of every 28-day cycle.

RESULTS

In 57 patients with measurable disease, median progression-free survival (PFS) was 4 months and median overall survival (OS) was 8 months. Overall response rate of 28% and disease stabilization in 19% were seen. There were no treatment-related deaths with grade 3/4 hematologic toxicity seen in 20% of the patients.

CONCLUSION

Biweekly GEMTAX is feasible, well tolerated, and demonstrated reasonable efficacy. This may be an alternative for patients who are not candidates for platinum-based chemotherapy.

Triplex-forming oligonucleotides targeting c-MYC potentiate the anti-tumor activity of gemcitabine in a mouse model of human cancer

Antimetabolite chemotherapy remains an essential cancer treatment modality, but often produces only marginal benefit due to the lack of tumor specificity, the development of drug resistance, and the refractoriness of slowly proliferating cells in solid tumors. Here, we report a novel strategy to circumvent the proliferation-dependence of traditional antimetabolite-based therapies. Triplex-forming oligonucleotides (TFOs) were used to target site-specific DNA damage to the human c-MYC oncogene, thereby inducing replication-independent, unscheduled DNA repair synthesis (UDS) preferentially in the TFO-targeted region. The TFO-directed UDS facilitated incorporation of the antimetabolite, gemcitabine (GEM), into the damaged oncogene, thereby potentiating the anti-tumor activity of GEM. Mice bearing COLO 320DM human colon cancer xenografts (containing amplified c-MYC) were treated with a TFO targeted to c-MYC in combination with GEM. Tumor growth inhibition produced by the combination was significantly greater than with either TFO or GEM alone. Specific TFO binding to the genomic c-MYC gene was demonstrated, and TFO-induced DNA damage was confirmed by NBS1 accumulation, supporting a mechanism of enhanced efficacy of GEM via TFO-targeted DNA damage-induced UDS. Thus, coupling antimetabolite chemotherapeutics with a strategy that facilitates selective targeting of cells containing amplification of cancer-relevant genes can improve their activity against solid tumors, while possibly minimizing host toxicity.

Hepatic intraarterial chemotherapy with gemcitabine in patients with unresectable cholangiocarcinomas and liver metastases of pancreatic cancer: a clinical study on maximum tolerable dose and treatment efficacy

PURPOSE

To define the maximum tolerated dose (MTD) of hepatic intraarterial chemotherapy with gemcitabine, administered with and without starch microspheres, in patients with inoperable intrahepatic cholangiocarcinomas and liver metastases of pancreatic carcinomas.

METHODS

Gemcitabine was administered on days 1 and 8 with intervals of 2 weeks between the cycles. In group A the initial gemcitabine dose of 1,000 mg/m(2) (without microspheres) was increased in 200-mg/m(2) steps up to a maximum dose of 2,000 mg/m(2). In group B the MTD with microspheres was assessed by giving an additional microsphere dose according to tumor extent and body weight, increasing gemcitabine starting from a dose-step below the MTD with microspheres. The MTD was evaluated via clinical and laboratory findings.

RESULTS

Twenty-four patients were enrolled (12 males, 12 females, mean age 59.17 years; intrahepatic cholangiocarcinoma: n = 17, liver metastases of pancreatic carcinoma: n = 7). The MTD of gemcitabine without microspheres was reached at 1,400 mg/m(2), and of gemcitabine with microspheres at 1,800 mg/m(2). The comparative evaluation revealed statistically significant better data for the time to progression (p < 0.01) and survival for the group with microspheres (6.8 and 20.2 months) in comparison to the group without microspheres (4.2 and 13.5 months).

CONCLUSION

This clinical study indicates that the intraarterial application of gemcitabine with doses higher than the recommended 1,000 mg/m(2) is well tolerated if combined with microspheres, and yields respectable results in patients who do not respond to systemic chemotherapy.