Effects of keratinocyte growth factor in the squamous epithelium of the upper aerodigestive tract of normal and irradiated mice

An extraoral approach to intraoral cooling-a feasibility study in non-cancer patients

BACKGROUND

Cryotherapy, using ice chips (IC) is an effective strategy to prevent chemotherapy-induced oral mucositis (OM) in selected cancer patient cohorts. However, although effective, use of IC may cause adverse reactions, e.g., nausea, numbness, and shooting pain in the teeth, which could have an adverse impact on the medical treatment. Furthermore, IC requires water of good quality to minimize risk of serious systemic infections. To eliminate these disadvantages, novel cooling devices have emerged as alternative cooling modalities. Thus, the aim was to evaluate the efficacy and tolerability profile of extraoral cooling for intraoral temperature reduction.

SUBJECTS AND METHODS

This experimental pilot study was conducted at the Institute of Odontology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden. In total, six healthy volunteers were enrolled in this study. At baseline and following 30-, and 60 min of cooling with the extraoral cooling device, intraoral mucosal temperatures were measured using a thermographic camera, and a questionnaire related to tolerability was completed.

RESULTS

Following 30-, and 60 min of cooling, the intraoral temperature decreased with 2.0 °C and 2.3 °C, respectively. Extraoral cooling was well tolerated, and all subjects endured the entire cooling session of 60 min.

CONCLUSION

Extraoral cooling reduces intraoral mucosal temperatures and is a well-tolerated cooling modality.

Durability of and role of AKT in FGF7p urothelial protection against cyclophosphamide

We previously identified a peptide derived from human fibroblast growth factor 7 (FGF7p) that blocks urothelial apoptosis similar to full-length FGF7, although effects of FGF7p on urothelial repair are unknown. Also, while urothelial AKT activation downstream of FGF7p correlated with the anti-apoptotic effects, we have not directly interrogated the role of AKT in mediating the cytoprotection. Our goal was to assess effects of FGF7p on urothelial repair and the role of AKT signaling in mediating the cytoprotective effects of FGF7p. We performed hematoxylin and eosin (H&E), TUNEL, and/or immunofluorescence (IF) staining for various markers in FGF7p-treated mice 28 days after giving cyclophosphamide or after co-administering a systemic AKT antagonist with FGF7p 24 h after cyclophosphamide. Vehicle-treated and injured mice had hyperplastic urothelium, incomplete return of mature superficial cell markers, ongoing proliferation, and continued presence of basal progenitor markers 28 days after injury; conversely, FGF7p-treated mice had normal numbers of urothelial cell layers, nearly complete return of superficial cell markers, limited proliferation and fewer basal progenitor cells 28 days post-injury. Vehicle-treated mice also had ectopic lumenal basal progenitor cell markers, while FGF7p had none 28 days after cyclophosphamide. Co-administration of an AKT inhibitor largely abrogated FGF7p-driven AKT activation and cytoprotection in urothelium 24 h after injury. Thus, FGF7p drives faster and higher fidelity urothelial repair by limiting apoptotic injury via AKT signaling, similar to full-length FGF7. Finally, FGF7p is much less expensive to synthesize and has a longer shelf life and higher purity than FGF7.

FGF7 peptide (FGF7p) mimetic mitigates bladder urothelial injury from cyclophosphamide

Although full-length fibroblast growth factor 7 (FGF7) blocks cyclophosphamide-induced urothelial apoptosis in mice, limitations include high production costs because of its large size. We previously identified a small peptide derived from FGF2 that mitigated acute radiation syndrome as well as full-length FGF2. Based on the sequence of the FGF2 peptide, we synthesized a corresponding 19 amino acid FGF7 peptide (FGF7p). Our objectives were to determine if systemic FGF7p triggered the downstream targets and protected against cyclophosphamide bladder injury similar to full-length FGF7. We administered FGF7p or vehicle subcutaneously (SQ) to mice subjected to no injury or intraperitoneal (IP) cyclophosphamide and harvested bladders 1 day after injury. We then performed hematoxylin and eosin, TUNEL and immunofluorescence (IF) staining. In uninjured mice, a 20 mg/kg threshold FGF7p dose induced expression of phosphorylated (activated) FRS2α (pFRS2α), and pAKT in urothelium (consistent with cytoprotective effects of FGF7). We then gave FGF7p (20 mg/kg) or vehicle at 72 and 48 h prior to cyclophosphamide. One day after injury, TUNEL staining revealed many more apoptotic urothelial cells with vehicle treatment versus FGF7p treatment. IF for pAKT and readouts of two anti-apoptotic AKT targets (BAD and mTORC1) revealed minimal staining with vehicle treatment, but strong urothelial expression for all markers with FGF7p treatment. In conclusion, FGF7p appears to block bladder urothelial apoptosis via AKT and its targets, similar to FGF7. FGF7p is much more inexpensive to make and has a longer shelf life and higher purity than FGF7.

Radiation countermeasures for hematopoietic acute radiation syndrome: growth factors, cytokines and beyond

PURPOSE

The intent of this article is to report the status of some of the pharmaceuticals currently in late stage development for possible use for individuals unwantedly and acutely injured as a result of radiological/nuclear exposures. The two major questions we attempt to address here are: (a) What medicinals are currently deemed by regulatory authorities (US FDA) to be safe and effective and are being stockpiled? (b) What additional agents might be needed to make the federal/state/local medicinal repositories more robust and useful in effectively managing contingencies involving radiation overexposures?

CONCLUSIONS

A limited number (precisely four) of medicinals have been deemed safe and effective, and are approved by the US FDA for the 'hematopoietic acute radiation syndrome (H-ARS).' These agents are largely recombinant growth factors (e.g. rhuG-CSF/filgrastim, rhuGM-CSF/sargramostim) that target and stimulate myeloid progenitors within bone marrow. Romiplostim, a small molecular agonist that enhances platelet production via stimulation of bone marrow megakaryocytes, has been recently approved and indicated for H-ARS. It is critical that additional agents for other major sub-syndromes of ARS (gastrointestinal-ARS) be approved. Future success in developing such medicinals will undoubtedly entail some form of a polypharmaceutical strategy, or perhaps novel, bioengineered chimeric agents with multiple, radioprotective/radiomitigative functionalities.

Repurposing Pharmaceuticals Previously Approved by Regulatory Agencies to Medically Counter Injuries Arising Either Early or Late Following Radiation Exposure

The increasing risks of radiological or nuclear attacks or associated accidents have served to renew interest in developing radiation medical countermeasures. The development of prospective countermeasures and the subsequent gain of Food and Drug Administration (FDA) approval are invariably time consuming and expensive processes, especially in terms of generating essential human data. Due to the limited resources for drug development and the need for expedited drug approval, drug developers have turned, in part, to the strategy of repurposing agents for which safety and clinical data are already available. Approval of drugs that are already in clinical use for one indication and are being repurposed for another indication is inherently faster and more cost effective than for new agents that lack regulatory approval of any sort. There are four known growth factors which have been repurposed in the recent past as radiomitigators following the FDA Animal Rule: Neupogen, Neulasta, Leukine, and Nplate. These four drugs were in clinic for several decades for other indications and were repurposed. A large number of additional agents approved by various regulatory authorities for given indications are currently under investigation for dual use for acute radiation syndrome or for delayed pathological effects of acute radiation exposure. The process of drug repurposing, however, is not without its own set of challenges and limitations.

Effect of Keratinocyte Growth Factor on Hospital Readmission and Regimen-Related Toxicities after Autologous Hematopoietic Cell Transplantation for Lymphoma

Regimen-related toxicities with high-dose therapy followed by hematopoietic cell rescue leads to considerable patient distress, morbidity, and high readmission rates. Palifermin is a recombinant keratinocyte growth factor that is Food and Drug Administration-approved to decrease severe oral mucositis (OM) associated with autologous hematopoietic cell transplantation (ASCT) for hematologic malignancies. We added palifermin as a supportive care measure for patients with lymphoma undergoing ASCT with BEAM conditioning. We compared patients receiving palifermin (n = 35) with historical controls (n = 38) for toxicity and readmission outcomes. The cumulative incidence of OM of any grade was 23% in the palifermin-treated patients and 42% in the control group. Patients receiving palifermin were less likely to be readmitted (57% versus 82%; P = .04), had fewer hospital readmission days (median, 4 days versus 7 days; P < .01), and had fewer total days in the hospital through day +30 after ASCT (median, 12 days versus 15 days; P = .05). Fewer patients in the palifermin group had >20 days in the hospital through day +30 (9% in the palifermin group versus 23% of controls). Adverse events associated with palifermin were mild and transient. The addition of palifermin limits severe regimen-related toxicities and decreases readmissions and duration of hospital stay. This and other measures are needed to identify comprehensive and cost-effective approaches, possibly including palifermin, to prevent severe regimen-related toxicities and decrease health care resource utilization.

Locally administered heparin-binding epidermal growth factor-like growth factor reduces radiation-induced oral mucositis in mice

Oral mucositis refers to lesions of the oral mucosa observed in patients with cancer being treated with radiation with or without chemotherapy, and can significantly affect quality of life. There is a large unmet medical need to prevent oral mucositis that can occur with radiation either alone or in combination with chemotherapy. We investigated the efficacy of locally administered heparin-binding epidermal growth factor-like growth factor (HB-EGF), a potent epithelial proliferation and migration stimulator of the oral mucosa as a potential therapy to prevent radiation induced oral mucositis. Using a single dose (20 Gy) of radiation to the oral cavity of female C57BL/6 J mice, we evaluated the efficacy of HB-EGF treatment (5 µl of 10 µg/ml) solution. The results show that HB-EGF delivered post radiation, significantly increased the area of epithelial thickness on the tongue (dorsal tongue (42,106 vs 53,493 µm2, p < 0.01), ventral tongue (30,793 vs 39,095 µm2, *p < 0.05)) compared to vehicle control, enhanced new epithelial cell division, and increased the quality and quantity of desmosomes in the oral mucosa measured in the tongue and buccal mucosa. This data provides the proof of concept that local administration of HB-EGF has the potential to be developed as a topical treatment to mitigate oral mucositis following radiation.

Comparative efficacy and safety of interventions for preventing chemotherapy-induced oral mucositis in adult cancer patients: a systematic review and network meta-analysis

Objective

To examine the comparative efficacy and safety of interventions for preventing chemotherapy-induced oral mucositis (OM) in adult cancer patients.

Methods

We searched PubMed, Embase and the Cochrane Central systematically for the randomised control trials (RCTs) of interventions for preventing OM. Network meta-analysis (NMA) was performed to estimate risk ratios (RR) and 95% confidence intervals (CI) from both direct and indirect evidence. The primary outcome was any grade of OM. Secondary outcomes were mild-moderate OM, severe OM and adverse events, such as taste disturbance and gastrointestinal adverse events. This study was registered with PROSPERO, number CRD42016052489.

Results

A total of 29 RCTs with 2348 patients (median age, 56.1 years; 57.5% male) were included. Cryotherapy was associated with a significantly lower risk of OM than control (RR 0.51, 95% CI 0.38 to 0.68), and zinc sulphate (RR 0.47, 95% CI 0.23 to 0.97), but not significantly lower than sucralfate and palifermin. No significant differences were observed between cryotherapy and control for taste disturbance and gastrointestinal adverse events. Palifermin was associated with the highest risk of taste disturbance.

Conclusions

This NMA suggests that cryotherapy was the most effective intervention for preventing chemotherapy-induced OM with a safety profile similar to control, but not significantly lower than sucralfate and palifermin. Large RCTs are needed to confirm these findings.

Role of drugs in the prevention and amelioration of radiation induced toxic effects

As the use of radiation technology for nuclear warfare or for the benefits of mankind (e.g. in radiotherapy or radio-diagnosis) is increasing tremendously, the risk of associated side effects is becoming a cause of concern. These effects, ranging from nausea/vomiting to death, may result from accidental or deliberate exposure and begin in seconds. Through this review paper, efforts have been done to critically review different compounds which have been investigated as radioprotectors and radiation mitigators. Radioprotectors are compounds which are administered just before or at the time of irradiation so as to minimize the radiation induced damage to normal tissues. And radiation mitigators are the compounds which can even minimize or ameliorate post irradiaion-toxicity provided they are administered before the onset of toxic symptoms. A variety of agents have been investigated for their preventive and ameliorative potential against radiation induced toxic effects. This review article has focused on various aspects of the promising representative agents belonging to different classes of radioprotectors and mitigators. Many compounds have shown promising results, but till date only amifostine and palifermin are clinically approved by FDA. To fill this void in pharmacological armamentarium, focus should be shifted towards novel approaches.

The Role Played by Growth Factors TGF-β1, EGF and FGF7 in the Pathogeny of Oral Pseudoepitheliomatous Hyperplasia

Pseudoepitheliomatous hyperplasia is an epithelial proliferation that develops in the dermis or lamina propria. It is a lesion associated to another pathology, which appears as a response to a great variety of infectious, neoplastic, inflammatory or traumatic stimuli. The etiopathogeny of this lesion is not clear yet. Therefore, we performed an immunohistochemical study on a group of 20 cases of pseudoepitheliomatous hyperplasia cases associated with inflammatory and neoplastic conditions, by investigating TGFβ1 (Beta growth and transformation factor), EGF (Epidermal growth Factor), and FGF7 (Fibroblast growth factor) expressions during in its development. The TGF-β1 expression was recorded in all the layers of the oral hyperplastic epithelium, going from the basal to the superficial layers, but with a different immunoreactive pattern, according to the region. Our study showed the absence of EGF immunoexpression in the carcinomatous proliferation areas associated to pseudoepitheliomatous hyperplasia and an almost exclusive presence in the hyperplasia lesions associated with inflammatory conditions (in about 30% of the investigated lesions) of a expression varying from poor to moderate for EGF. According to our investigations, we observed the presence of an immunolabeling for FGF7 in 80% of the investigated cases of pseudoepitheliomatous hyperplasia, a maximum of intensity being observed within the cases associated with inflammatory conditions.

Retrospective Evaluation of Palifermin Use in Nonhematopoietic Stem Cell Transplant Pediatric Patients

BACKGROUND

Palifermin has been proven to decrease the frequency of severe oral mucositis in adult patients with sarcoma and metastatic colorectal cancer receiving chemotherapy. The impact of palifermin on the incidence of mucositis in nonhematopoietic stem cell transplantation (HSCT) pediatric population receiving chemotherapy has never been reported to date.

PATIENTS AND METHODS

This is a retrospective analysis of pediatric patients who received palifermin as secondary prophylaxis to prevent chemotherapy-induced mucositis at Memorial Sloan Kettering Cancer Center from January 1, 2008 to 2014. Data from electronic medical records on days to mucositis resolution, use of opioids, use of total parenteral nutrition, duration of hospitalization, and antibiotics are collected and presented here.

RESULTS

A total of 18 patients received palifermin for secondary prophylaxis after developing mucositis from the prior chemotherapy cycle. Mucositis did not reoccur in the subsequent cycle for 13 of the 18 patients. The majority of patients who received palifermin prophylaxis had decreased opioids and antibiotics use and decreased duration of hospitalization. Six of the 7 patients previously requiring total parenteral nutrition due to mucositis had decreased supplemental nutritional needs following the use of palifermin.

CONCLUSION

Palifermin may provide benefit as secondary prophylaxis in pediatric patients to prevent chemotherapy-induced mucositis.

Promising Gene Therapeutics for Salivary Gland Radiotoxicity

More than 0.5 million new cases of head and neck cancer are diagnosed worldwide each year, and approximately 75% of them are treated with radiation alone or in combination with other cancer treatments. A majority of patients treated with radiotherapy develop significant oral off-target effects because of the unavoidable irradiation of normal tissues. Salivary glands that lie within treatment fields are often irreparably damaged and a decline in function manifests as dry mouth or xerostomia. Limited ability of the salivary glands to regenerate lost acinar cells makes radiation-induced loss of function a chronic problem that affects the quality of life of the patients well beyond the completion of radiotherapy. The restoration of saliva production after irradiation has been a daunting challenge, and this review provides an overview of promising gene therapeutics that either improve the gland’s ability to survive radiation insult, or alternately, restore fluid flow after radiation. The salient features and shortcomings of each approach are discussed.

Palifermin for the protection and regeneration of epithelial tissues following injury: new findings in basic research and pre-clinical models

Keratinocyte growth factor (KGF) is a paracrine-acting epithelial mitogen produced by cells of mesenchymal origin, that plays an important role in protecting and repairing epithelial tissues. Pre-clinical data initially demonstrated that a recombinant truncated KGF (palifermin) could reduce gastrointestinal injury and mortality resulting from a variety of toxic exposures. Furthermore, the use of palifermin in patients with hematological malignancies reduced the incidence and duration of severe oral mucositis experienced after intensive chemoradiotherapy. Based upon these findings, as well as the observation that KGF receptors are expressed in many, if not all, epithelial tissues, pre-clinical studies have been conducted to determine the efficacy of palifermin in protecting different epithelial tissues from toxic injury in an attempt to model various clinical situations in which it might prove to be of benefit in limiting tissue damage. In this article, we review these studies to provide the pre-clinical background for clinical trials that are described in the accompanying article and the rationale for additional clinical applications of palifermin.

Impact of palifermin on incidence of oral mucositis and healthcare utilization in children undergoing autologous hematopoietic stem cell transplantation for malignant diseases

Palifermin has been demonstrated to decrease the incidence of severe oral mucositis in adults following TBI containing conditioning regimens prior to AHSCT. The impact of palifermin on the incidence of oral mucositis in children undergoing AHSCT has never been studied. We compared the effect of palifermin on the incidence of oral mucositis and supportive care in 58 children undergoing myeloablative AHSCT; 25 children received palifermin and 33 children did not receive palifermin (control arm). Oral mucositis was graded as per WHO criteria. The demographic characteristics were comparable between the two arms. Results comparing the palifermin vs. control arm showed that the incidence of grade III-IV oral mucositis was 20% vs. 42.4% (p = 0.072). The number of days patients received patient-controlled analgesia and total parenteral nutrition in the palifermin vs. control arm were 8.80 ± 8.39 vs. 8.30 ± 8.54 (p = 0.826) and 13.52 ± 11.32 vs. 11.55 ± 9.63 (p = 0.484), respectively. The average length of hospitalization in the palifermin vs. control arm was 31.44 ± 7.42 vs. 28.61 ± 10.38 (p = 0.252), respectively. In this study, we were unable to demonstrate a statistical difference in the incidence of oral mucositis and other supportive care needs or a decrease in hospital stay between the two arms.

Treatment of Radiation Injury

Significance: Radiation exposure as a result of radiation treatment, accident, or terrorism may cause serious problems such as deficiency due to necrosis or loss of function, fibrosis, or intractable ulcers in the tissues and organs. When the skin, bone, oral mucous membrane, guts, or salivary glands are damaged by ionizing radiation, the management and treatment are very lengthy and difficult. Critical Issues: In severe and irreversible injuries, surgery remains the mainstay of treatment. Several surgical procedures, such as debridement, skin grafting, and local and free-vascularized flaps, are widely used. Recent Advances: In specific cases of major morbidity or in high-risk patients, a newly developed therapy using a patient's own stem cells is safe and effective. Adipose tissue, normally a rich source of mesenchymal stem cells, which are similar to those from the bone marrow, can be harvested, since the procedure is easy, and abundant tissue can be obtained with minimal invasiveness. Future Directions: Based on the molecular basis of radiation injuries, several prospective treatments are under development. Single-nucleotide polymorphisms focus on an individual's sensitivity to radiation in radiogenomics, and the pathology of radiation fibrosis or the effect of radiation on wound healing is being studied and will lead to new insight into the treatment of radiation injuries. Protectors and mitigators are being actively investigated in terms of the timing of administration or dose.

Clinical applications of palifermin: amelioration of oral mucositis and other potential indications

Mucositis is one of the most significant toxicities in cancer patients undergoing cytotoxic treatment. It can have a negative impact on both quality of life and health economics. Severe oral mucositis can contribute to hospitalization, need for narcotic analgesics, total parentral nutrition, suboptimal delivery of anti-neoplastic treatment, and morbidity and mortality. Palifermin, a recombinant derivative of human keratinocyte growth factor, is the first active agent approved by the FDA for the prevention of severe oral mucositis in patients undergoing haematopoietic stem cell transplantation (HSCT). Several studies have also shown significant reduction in the incidence, severity and/or duration of oral mucositis in other high-risk settings such as concurrent chemoradiotherapy (CT/RT) for patients with head and neck cancer, and use of mucotoxic chemotherapeutic agents such as doxorubicin in sarcoma and fluorouracil for the treatment of colorectal cancer. The reduction in mucositis has translated into amelioration of symptoms and improvement in daily functioning as measured by patient-reported outcome in multiple studies. The clinical response to palifermin appears to be related in part to epithelial proliferation and mucosal thickening. Palifermin also has other potential clinical applications including the acceleration of immune reconstitution and inhibition of graft-versus-host disease in patients undergoing HSCT, and mitigation of dysphagia in lung cancer patients treated with concurrent CT/RT. Palifermin is generally well tolerated with mild-to-moderate skin and oral adverse events. Future studies may expand the use of palifermin into other areas that would benefit from its cytoprotective and regenerative effects.

Strategies for optimizing the response of cancer and normal tissues to radiation

Approximately 50% of all patients with cancer receive radiation therapy at some point during the course of their treatment, and the majority of these patients are treated with curative intent. Despite recent advances in the planning of radiation treatment and the delivery of image-guided radiation therapy, acute toxicity and potential long-term side effects often limit the ability to deliver a sufficient dose of radiation to control tumours locally. In the past two decades, a better understanding of the hallmarks of cancer and the discovery of specific signalling pathways by which cells respond to radiation have provided new opportunities to design molecularly targeted therapies to increase the therapeutic window of radiation therapy. Here, we review efforts to develop approaches that could improve outcomes with radiation therapy by increasing the probability of tumour cure or by decreasing normal tissue toxicity.

Keratinocyte growth factor pretreatment prevents radiation-induced intestinal damage in a mouse model

BACKGROUND

Radiation-induced gastrointestinal syndrome is usually severe in clinical practice. Keratinocyte growth factor (KGF) plays an important role in the intestinal mucosal growth and repair of intestinal injury. This study was to investigate the effects of KGF on radiation-induced intestinal damage, especially the barrier dysfunction, in a mouse model.

METHODS

Adult C57BL/6J mice were randomized into three groups: normal control, irradiation group, and KGF-treated group. Mice in the later two groups received irradiation with a dose of 6 Gy from Co-60 source. In the KGF-treated group, KGF was intraperitoneally given once daily (5 mg/kg/day) for 5 consecutive days before irradiation. Mice were killed at 3 days after irradiation and the small bowel was collected for histology. Epithelial cell proliferation was studied by immunohistochemistry for proliferating cell nuclear antigen. Claudin-1 and ZO-1 expressions were determined by western blot assay and immunohistochemistry. Epithelial barrier function was assessed with transepithelial resistance.

RESULTS

KGF significantly promoted the recovery of mucosa from radiation-induced injury demonstrated by mucosal histology, villus height, crypt depth, and crypt cell proliferation. KGF also improved the disrupted distribution of tight junction proteins and the epithelial barrier dysfunction after irradiation.

CONCLUSION

KGF pretreatment could improve radiation-induced intestinal injury including the epithelial structure and function in a mouse model.

Palifermin is efficacious in recipients of TBI-based but not chemotherapy-based allogeneic hematopoietic stem cell transplants

Palifermin, a recombinant human keratinocyte growth factor, is commonly given to prevent mucositis following autologous transplantation. In the allogeneic hematopoietic stem cell transplant (allo-HSCT) setting, safety and efficacy data are limited. We conducted a retrospective study in 251 patients undergoing allo-HSCT, 154 of whom received peritransplant palifermin. In all patients, palifermin significantly decreased the mean number of days of total parenteral nutrition (TPN, 13 vs 16 days, P=0.006) and patient-controlled analgesia (PCA, 6 vs 10 days, P=0.023), as well as the length of initial hospital stay (LOS, 32 vs 37 days, P=0.014). However, the effect of palifermin was only significant in patients who received a TBI- but not BU-based chemotherapy conditioning regimen. In TBI recipients, palifermin decreased the mean number of days of TPN (13 vs 17 days, P<0.001) and PCA (7 vs 12 days, P=0.033), and the length of stay (32 vs 38 days, P=0.001). Palifermin did not affect GVHD, graft failure or relapse. Therefore, in the largest analysis with this patient population to date, we demonstrate that palifermin is safe in allo-HSCT patients, decreases TPN and PCA use and decreases LOS following TBI-based but not chemotherapy-based allo-HSCT.

Randomized phase II study of palifermin for reducing dysphagia in patients receiving concurrent chemoradiotherapy for locally advanced unresectable non-small cell lung cancer

INTRODUCTION

Dysphagia is a common, dose-limiting toxicity of combined chemoradiotherapy (CT/RT) in patients with locally advanced non-small cell lung cancer (NSCLC). This study assessed the efficacy and safety of palifermin in reducing dysphagia from CT/RT followed by consolidation chemotherapy (CT).

METHODS

This randomized, double-blind, phase II trial enrolled adults with unresectable stage III NSCLC. Subjects received weekly paclitaxel (50 mg/m2) and carboplatin (AUC 2.0) with concurrent daily radiation (RT) of 6000 to 6600 cGy, followed by consolidation CT. Palifermin (n = 49) or placebo (n = 46) was administered before starting concurrent CT/RT and once weekly for 6 weeks. The primary end points were the incidence of grade ≥ 2 dysphagia and safety.

RESULTS

The incidence of grade ≥ 2 and ≥ 3 dysphagia was numerically lower in palifermin subjects versus placebo subjects (61% versus 70%; p = 0.36; 22% versus 28%, p = 0.50, respectively). Mean duration of dysphagia (grade ≥ 2) was 25 days for palifermin subjects and 32 days for placebo subjects (p = 0.32). The incidence of adverse events was similar in the two treatment groups, and median overall survival and progression-free survival were not adversely affected by palifermin treatment (overall survival: 513 versus 319 days; progression-free survival: 262 versus 235 days for palifermin versus placebo arms, respectively). The palifermin arm received more doses of CT per study design and significantly more patients received RT doses ≥ 6000 cGy (84% versus 61%, p = 0.01).

CONCLUSIONS

The results of this exploratory trial suggest that additional larger studies may be warranted to further evaluate the effect of palifermin on dysphagia, exposure to CT/RT, and long-term survival.

Phase I study of the tolerability and pharmacokinetics of palifermin in children undergoing allogeneic hematopoietic stem cell transplantation

The maximum tolerated dose of palifermin, a keratinocyte growth factor, in children is not known, and its pharmacokinetics in this population has not been well studied. This is a phase I study of palifermin was designed to evaluate its tolerability at doses of 40, 60, and 90 μg/kg/day in children age 2-18 years of age, receiving a myeloablative preparative regimen for allogeneic hematopoietic stem cell transplantation (HSCT). In each cohort, palifermin was given for 3 consecutive days before the preparative regimen and for 3 days after the stem cell infusion. Twelve patients were enrolled. Palifermin 90 μg/kg/day was tolerated in 6 patients without dose-limiting toxicity. All patients had at least 1 adverse event, mostly National Cancer Institute grade 1 or 2 severity. Skin rash, grade 2 or lower, was the most common adverse event, seen in 67% of patients. Only 3 patients (25%) had mucositis. The area under the concentration-time curve increased proportionally to the dose, and approximately 97% of palifermin exposure occurred in the first 24 hours after administration. Palifermin clearance increased linearly with body weight, supporting dosing by body weight. The mean clearance was 1893 mL/hour/kg, and it did not change significantly between administration of the first and last doses (P = .80). The mean elimination half-life was 4.6 hours. Our data show that palifermin was tolerated at a dose of 90 μg/kg/day, and exhibits linear pharmacokinetics in children undergoing allogeneic HSCT.

Role of AMP-18 in oral mucositis

Oral mucositis (OM) is a devasting toxicity associated with cytotoxic cancer therapy. Antrum mucosal protein (AMP)-18 and a synthetic peptide surrogate, exhibit cell protective and mitogenic properties in in vitro and in vivo models of gastrointestinal epithelial cell injury. The mucosal barrier-protective effects may be mediated by AMP-18's capacity to increase accumulation of specific tight junction (TJ) and adherens junction proteins, and also protect against their loss after injury. Here we asked if AMP peptide could protect the oral mucosa and speed healing from radiation-induced injury. We found AMP peptide prevented radiation-induced OM in a murine model. The peptide also stimulated HaCaT cell growth used to model the oral mucosa. Binding of recombinant human (rh) AMP-18 to the plasma membrane of keratinocytes in normal human oral mucosal tissue suggested that its effects may be receptor mediated. Using an immobilized His-tagged rhAMP-18 fusion protein the receptor was identified as the cholecystokinin-B/gastrin receptor (CCKBR) by affinity purification and mass spectrometry analysis. CCKBR was expressed and co-immunoprecipitated with exogenous rhAMP-18 in diverse epithelial cell lines. Immunofluorescence staining revealed that rhAMP-18 colocalized with CCKBR on the surface of CCKBR-transfected cells. Furthermore, rhAMP-18-stimulated signaling pathways were blocked by a CCKBR-specific antagonist, YM022. rhAMP-18 enhanced viability and growth of CCKBR-transfected, but not empty vector-transfected cells. These results suggest the importance of epithelial junctional integrity in the pathogenesis of OM and demonstrate that AMP-18, by targeting TJ proteins through the activation of CCKBR, could provide a novel strategy for the prevention and treatment of OM.

Prevention of radiation-induced salivary hypofunction following hKGF gene delivery to murine submandibular glands

PURPOSE

Salivary glands are significantly affected when head and neck cancer patients are treated by radiation. We evaluated the effect of human keratinocyte growth factor (hKGF) gene transfer to murine salivary glands on the prevention of radiation-induced salivary hypofunction.

EXPERIMENTAL DESIGN

A hybrid serotype 5 adenoviral vector encoding hKGF (AdLTR(2)EF1α-hKGF) was constructed. Female C3H mice, 8 weeks old, were irradiated by single (15 Gy) or fractionated (6 Gy for 5 days) doses to induce salivary hypofunction. AdLTR(2)EF1α-hKGF or AdControl was administered (10(8) - 10(10) particles per gland) to both submandibular glands (SG) by retrograde ductal instillation before irradiation (IR). Salivary flow was measured following pilocarpine stimulation. Human KGF levels were measured by ELISA. SG cell proliferation was measured with bromodeoxyuridine labeling. Endothelial and progenitor or stem cells in SGs were measured by flow cytometry. The effect of SG hKGF production on squamous cell carcinoma (SCC VII) tumor growth was assessed.

RESULTS

In 3 separate single-dose IR experiments, salivary flow rates of mice administered the AdLTR(2)EF1α-hKGF vector were not significantly different from nonirradiated control mice (P > 0.05). Similarly, in 3 separate fractionated IR experiments, the hKGF-expressing vector prevented salivary hypofunction dramatically. Transgenic hKGF protein was found at high levels in serum and SG extracts. AdLTR(2)EF1α-hKGF-treated mice showed increased cell proliferation and numbers of endothelial cells, compared with mice treated with AdControl. hKGF gene transfer had no effect on SCC VII tumor growth ± radiation.

CONCLUSIONS

hKGF gene transfer prevents salivary hypofunction caused by either single or fractionated radiation dosing in mice. The findings suggest a potential clinical application.

Radioprotectors and mitigators of radiation-induced normal tissue injury

Radiation is used in the treatment of a broad range of malignancies. Exposure of normal tissue to radiation may result in both acute and chronic toxicities that can result in an inability to deliver the intended therapy, a range of symptoms, and a decrease in quality of life. Radioprotectors are compounds that are designed to reduce the damage in normal tissues caused by radiation. These compounds are often antioxidants and must be present before or at the time of radiation for effectiveness. Other agents, termed mitigators, may be used to minimize toxicity even after radiation has been delivered. Herein, we review agents in clinical use or in development as radioprotectors and mitigators of radiation-induced normal tissue injury. Few agents are approved for clinical use, but many new compounds show promising results in preclinical testing.

Effect of tumour-cell-derived or recombinant keratinocyte growth factor (KGF) on proliferation and radioresponse of human epithelial tumour cells (HNSCC) and normal keratinocytes in vitro

Purpose of this work was to test the effect of tumour-cell-derived keratinocyte growth factor (KGF) or recombinant KGF (palifermin) on cell proliferation and radiation response of human HNSCC cells and normal keratinocytes in vitro. Four tumour cell cultures derived from head and neck squamous cell carcinomas, primary keratinocytes, and immortalized keratinocytes were analysed. Fibroblasts, the natural source of KGF protein, served as controls. KGF expression was observed in primary and immortalized keratinocytes, fibroblasts, and in tumour cells, while significant KGF receptor expression was only found in keratinocytes. Recombinant KGF as well as tumour-cell-derived KGF caused a significant growth stimulation and radioprotection in keratinocytes, which was abolished by a neutralizing anti-KGF antibody. This indicates that tumour-cell-derived KGF is biologically active. In the tumour cell lines, no significant growth stimulation was induced by recombinant KGF, and the neutralizing antibody did not influence tumour cell growth or radiation response. Our results indicate that the normal, paracrine KGF regulatory mechanisms, which are based on KGF receptor expression, are lost in malignant cells, with the consequence of irresponsiveness of the tumour cells to exogenous KGF. In face of the amelioration of the radiation response of normal epithelia, demonstrated in various clinical and various preclinical animal studies, recombinant KGF represents a candidate for the selective protection of normal epithelia during radio(chemo) therapy of squamous cell carcinoma.

Palifermin for management of treatment-induced oral mucositis in cancer patients

Oral mucositis (OM) remains a major side effect of various cancer therapies, which exacts a significant price in terms of morbidity and cost of care. Efforts aimed at prevention and/or therapy of OM have been largely unsuccessful. Few agents have shown efficacy, and even those were applicable to limited types of patients. The advent of small-molecule targeted agents opened new possibilities for intervention in the mucopathogenic processes induced by cancer therapies. One of these agents, recombinant human keratinocyte growth factor (KGF), has been studied extensively and has shown promising results in reducing chemotherapy induced OM. This drug's effects on stem cell engraftment, graft-versus-host disease and other treatment-induced morbidities remain undefined. In this article we evaluate the pre-clinical and clinical evidence and discuss the clinical applications of KGF as an adjunct therapeutic agent in oncology.

Prevention of radiation-induced oral mucositis after adenoviral vector-mediated transfer of the keratinocyte growth factor cDNA to mouse submandibular glands

PURPOSE

The study aims to evaluate if human keratinocyte growth factor (hKGF), secreted after transduction of murine salivary glands with adenoviral vectors, can prevent oral mucositis resulting from radiation.

EXPERIMENTAL DESIGN

Two serotype 5 adenoviral vectors encoding hKGF were constructed: AdEF1alpha-hKGF and AdLTR(2)EF1alpha-hKGF. Female C3H mice, 8 weeks old, were irradiated by single (22.5 Gy) or fractionated (5 x 8 Gy for 5 days) doses to induce oral mucositis (ulcers on tongue). One day before irradiation, the above viral vectors or an empty vector, Adcontrol, was given (10(10) particles per gland) to both submandibular glands by retrograde ductal instillation. Each experiment included five groups: no irradiation and irradiation (+/-Adcontrol, AdEF1alpha-hKGF, or AdLTR(2)EF1alpha-hKGF). Blood, saliva, submandibular glands, and tongue were collected on day 7 for single-dose studies or day 10 for fractionated dosing. hKGF levels were measured by ELISA.

RESULTS

In three separate single-dose irradiation experiments, lingual ulcers were dramatically reduced after either KGF-expressing vector. Similarly, in two separate fractionated irradiation experiments, the hKGF-expressing vectors completely prevented ulcer formation. QPCR data indicated that approximately 10(7) to 10(8) particles of each vector remained in the targeted submandibular glands at the terminal time. Transgenic hKGF protein was found at high levels in saliva, serum, and submandibular gland extracts.

CONCLUSIONS

hKGF gene transfer to salivary glands prevented radiation-induced oral mucositis in mice. This proof of concept study suggests that transgenic hKGF secreted from transduced salivary glands may be useful clinically to prevent oral mucositis caused by radiation.

R-Spondin1 protects mice from chemotherapy or radiation-induced oral mucositis through the canonical Wnt/beta-catenin pathway

R-Spondin1 (RSpo1) is a novel secreted protein that augments canonical Wnt/beta-catenin signaling. We injected recombinant RSpo1 protein into transgenic Wnt reporter TOPGAL mice and have identified the oral mucosa as a target tissue for RSpo1. Administration of RSpo1 into normal mice triggered nuclear translocation of beta-catenin and resulted in increased basal layer cellularity, thickened mucosa, and elevated epithelial cell proliferation in tongue. We herein evaluated the therapeutic potential of RSpo1 in treating chemotherapy or radiotherapy-induced oral mucositis in several mouse models. Prophylactic treatment with RSpo1 dose-dependently overcame the reduction of basal layer epithelial cellularity, mucosal thickness, and epithelial cell proliferation in tongues of mice exposed to whole-body irradiation. RSpo1 administration also substantially alleviated tongue mucositis in the oral cavity of mice receiving concomitant 5-fluorouracil and x-ray radiation. Furthermore, RSpo1 significantly reduced the extent of tongue ulceration in mice receiving a single fraction, high dose head-only radiation in a dose-dependent manner. Moreover, combined therapy of RSpo1 and keratinocyte growth factor resulted in complete healing of tongue ulcers in mice subjected to snout-only irradiation. In conclusion, our results demonstrate RSpo1 to be a potent therapeutic agent for oral mucositis by enhancing basal layer epithelial regeneration and accelerating mucosal repair through up-regulation of Wnt/beta-catenin pathway.

Low-level infrared laser therapy in chemotherapy-induced oral mucositis: a randomized placebo-controlled trial in children

BACKGROUND

Oral mucositis (OM) is one of the most frequent complications of chemotherapy for which there is no standard therapy; treatment is mostly conservative. This study was conducted to determine whether low-intensity laser therapy (LLLT) can reduce the duration of chemotherapy-induced OM.

PROCEDURE

A placebo-controlled randomized trial was carried out using LLLT or placebo (sham treatment). Children and adolescents with cancer receiving chemotherapy or hematopoietic stem-cell transplantation between October 2005 and May 2006 were eligible as soon as they developed OM. Patients received intervention for 5 days. The LLLT group was treated with laser GaAlAs, wavelength (lambda): 830 nm (infrared), power: 100 mW, dose: 4 J/cm, and placebo group underwent sham treatment. The grade of OM was clinically assessed by the National Cancer Institute, Common Toxicity Criteria scale.

RESULTS

Twenty-one patients developed OM and were evaluable for analysis; 18 (86%) patients had a diagnosis of leukemia or lymphoma and 3(14%) had solid tumors. The mean age was 8.2 (+/-3.1) years. Nine patients were randomized in the laser group and 12 in the placebo-control group. Once OM was diagnosed, the patients had daily OM grading assessments before laser or sham application and thereafter until complete healing of the lesions. On day 7 after OM diagnosis, 1/9 of patients remained with lesions in laser group and 9/12 of patients in the placebo-control group (P=0.029). In the laser group, the mean of OM duration was 5.8+/-2 days and in the placebo group was 8.9+/-2.4 days (P=0.004).

CONCLUSIONS

Our study has shown evidence that laser therapy in addition to oral care can decrease the duration of chemotherapy-induced OM. Our results confirm the promising results observed in adult cancer patients and should encourage pediatric oncologists to use laser therapy as first-line option in children with chemotherapy-induced OM.

Gut protection by palifermin during autologous haematopoietic SCT

Conditioning therapy in connection with haematopoietic SCT (HSCT) induces a disruption of the intestinal barrier function facilitating the permeation of bacteria and endotoxin through the bowel wall with subsequent increased risk of septicaemia and a worsening of GVHD in the allogeneic setting. Palifermin (recombinant human keratinocyte growth factor) reduces the severity of oral mucositis with HSCT. The present trial investigates its effect on intestinal barrier function. Seventeen lymphoma patients undergoing autologous HSCT received palifermin. Intestinal permeability was assessed before the conditioning therapy and on days +4 and +14. Clinical oral and gastrointestinal toxicity was prospectively assessed in parallel. A comparison was made with matched historical study patients (n=21). Patients treated with palifermin had a significantly better preserved intestinal barrier function (P=0.01 on day +4) and were in less need of total parenteral nutrition (P=0.005) as compared with controls. No significant reduction of clinical gastrointestinal or oral toxicity was observed. The intestinal barrier function, normally disrupted by the conditioning therapy, is preserved by palifermin. Whether intestinal barrier preservation protects from invasive infections, and in the allogeneic setting diminishes GVHD severity, remains to be investigated in randomized controlled trials.

American Society of Clinical Oncology 2008 clinical practice guideline update: use of chemotherapy and radiation therapy protectants

PURPOSE

To update a clinical practice guideline on the use of chemotherapy and radiation therapy protectants for patients with cancer.

METHODS

An update committee reviewed literature published since the last guideline update in 2002.

RESULTS

Thirty-nine reports met the inclusion criteria: palifermin and dexrazoxane, three reports (two studies) each; amifostine, 33 reports (31 studies); and mesna, no published randomized trials identified since 2002.

RECOMMENDATIONS

Dexrazoxane is not recommended for routine use in breast cancer (BC) in adjuvant setting, or metastatic setting with initial doxorubicin-based chemotherapy. Consider use with metastatic BC and other malignancies, for patients who have received more than 300 mg/m(2) doxorubicin who may benefit from continued doxorubicin-containing therapy. Cardiac monitoring should continue in patients receiving doxorubicin. Amifostine may be considered for prevention of cisplatin-associated nephrotoxicity, reduction of grade 3 to 4 neutropenia (alternative strategies are reasonable), and to decrease acute and late xerostomia with fractionated radiation therapy alone for head and neck cancer. It is not recommended for protection against thrombocytopenia, prevention of platinum-associated neurotoxicity or ototoxicity or paclitaxel-associated neuropathy, prevention of radiation therapy-associated mucositis in head and neck cancer, or prevention of esophagitis during concurrent chemoradiotherapy for non-small-cell lung cancer. Palifermin is recommended to decrease severe mucositis in autologous stem-cell transplantation (SCT) for hematologic malignancies with total-body irradiation (TBI) conditioning regimens, and considered for patients undergoing myeloablative allogeneic SCT with TBI-based conditioning regimens. Data are insufficient to recommend use in the non-SCT setting.

Palifermin-induced flexural hyperpigmentation: a clinical and histological study of five cases

Palifermin is a human keratinocyte growth factor that is efficacious in reducing duration and severity of oral mucositis during autologous haematopoietic stem-cell transplantation for haematological cancer as well as chemotherapy for colorectal cancers. We report the clinical and histological characteristics of a series of five patients who developed flexural hyperpigmentation after treatment with palifermin. All patients showed ill-defined symmetrical hyperpigmented papillomatous plaques with slight erythema in the skin folds, especially affecting axillary and inguinal areas. The most striking histological finding was the thickened granular layer in all patients. We demonstrate that filaggrin, an essential component in the terminal differentiation of the epidermis, was upregulated in these cases. Palifermin-induced flexural hyperpigmentation is a newly defined clinical and histological entity. The possible aetiology is discussed.

Keratinocyte growth factor prevents radiation damage to salivary glands by expansion of the stem/progenitor pool

Irradiation of salivary glands during radiotherapy treatment of patients with head and neck cancer evokes persistent hyposalivation. This results from depletion of stem cells, which renders the gland incapable of replenishing saliva to produce acinar cells. The aim of this study was to investigate whether it is possible to expand the salivary gland stem/progenitor cell population, thereby preventing acinar cell depletion and subsequent gland dysfunction after irradiation. To induce cell proliferation, keratinocyte growth factor (DeltaN23-KGF, palifermin) was administered to C57BL/6 mice for 4 days before and/or after local irradiation of salivary glands. Salivary gland vitality was quantified by in vivo saliva flow rates, morphological measurements, and a newly developed in vitro salisphere progenitor/stem cell assay. Irradiation of salivary glands led to a pronounced reduction in the stem cells of the tissues, resulting in severe hyposalivation and a reduced number of acinar cells. DeltaN23-KGF treatment for 4 days before irradiation indeed induced salivary gland stem/progenitor cell proliferation, increasing the stem and progenitor cell pool. This did not change the relative radiation sensitivity of the stem/progenitor cells, but, as a consequence, an absolute higher number of stem/progenitor cells and acinar cells survived after radiation. Postirradiation treatment with DeltaN23-KGF also improved gland function, and this effect was much more pronounced in DeltaN23-KGF pretreated animals. Post-treatment with DeltaN23-KGF seemed to act through accelerated expansion of the pool of progenitor/stem cells that survived the irradiation treatment. Overall, our data indicate that DeltaN23-KGF is a promising drug to enhance the number of salivary gland progenitor/stem cells and consequently prevent radiation-induced hyposalivation. Disclosure of potential conflicts of interest is found at the end of this article.

Pharmacokinetics of Palifermin Administered as the Standard Dose and as a Collapsed Dose in Patients with Hematologic Malignancies

STUDY OBJECTIVE

To assess the pharmacokinetic profile of palifermin after intravenous dosing with either a collapsed dose of 180 microg/kg/day for 1 day or a standard dose of 60 microg/kg/day for 3 days, before and after myeloablative chemoradiotherapy and peripheral blood progenitor cell (PBPC) transplantation.

DESIGN

Prospective, open-label pharmacokinetic study.

SETTING

University-affiliated hematology and oncology center.

PATIENTS

Twenty-five adult patients with hematologic malignancies receiving myeloablative therapy; 13 were in the standard-dose group, and 12 were in the collapsed-dose group.

INTERVENTION

Patients received total-body irradiation (study days -8 to -5), etoposide (day -4), cyclophosphamide (day -2), and PBPC transplantation (day 0). Standard-dose palifermin was administered on days -11, -10, -9, 0, 1, and 2; collapsed-dose palifermin was administered on days -11 and 0.

MEASUREMENTS AND MAIN RESULTS

Baseline demographic and clinical characteristics were recorded. Blood samples were obtained for pharmacokinetic assessment, presence of palifermin antibodies, and routine chemistry and hematology panels. Adverse events were documented daily. For both dosing groups, palifermin concentrations declined rapidly (>or= 98%) in the first 30 minutes and increased slightly between 1 and 4 hours after dosing, with a terminal decay phase. For standard-dose palifermin, mean values for area under the serum concentration-time curve (AUC) were within 15% between doses 1 and 3 and within 1% between doses 1 and 4. For collapsed-dose palifermin, mean AUC values and other pharmacokinetic parameters were within 2% between doses 1 and 2. Mean AUC on days -11 and 0 were approximately 4-fold higher for collapseddose palifermin than for standard-dose palifermin. Both dosing regimens were well tolerated.

CONCLUSIONS

Our results were consistent with approximately dose-linear pharmacokinetics for the two dosing regimens, with no observed accumulation. A randomized, controlled study is warranted to assess the safety and efficacy of collapsed-dose palifermin, which may provide a more convenient administration schedule.

KGF promotes integrin alpha5 expression through CCAAT/enhancer-binding protein-beta

Keratinocyte growth factor (KGF) and alpha(5)beta(1)-integrin are not expressed in normal skin but they are both highly upregulated in the migrating epidermis during wound healing. Here we report that KGF increased alpha(5) mRNA and protein levels in epidermoid carcinoma cells and stratified bioengineered epidermis. Interestingly, KGF increased integrin alpha(5) in the basal as well as suprabasal cell epidermal layers. Promoter studies indicated that KGF-induced integrin alpha(5) promoter activation was dependent on the C/EBP transcription factor binding site. Accordingly, KGF induced sustained phosphorylation of C/EBP-beta that was dependent on activation of ERK1/2. In addition, a dominant negative form of C/EBP-beta inhibited alpha(5) promoter activity and blocking C/EBP-beta with siRNA diminished integrin alpha(5) expression. Taken together, our data indicate that KGF increased integrin alpha(5) expression by phosphorylating C/EBP-beta. Interestingly, KGF-induced upregulation of integrin alpha(5) was more pronounced in three-dimensional tissue analogues than in conventional two-dimensional culture suggesting that stratified epidermis may be useful in understanding the effects of growth factors in the local tissue microenvironment.

Effect of post-exposure administration of keratinocyte growth factor (Palifermin) on radiation effects in oral mucosa in mice

Oral mucositis is a severe component of the acute radiation syndrome. The present study was initiated to determine the potential of recombinant human keratinocyte growth factor (rHuKGF, Palifermin) to ameliorate oral mucositis in a mouse model after a single radiation exposure. A 3 x 3 mm(2 )area in the center of the lower tongue surface of C3H/Neu mice was irradiated with graded single doses of 25 kV X-rays. Acute mucosal ulceration was used as the quantal end-point for dose-response analyses. Palifermin was applied at a dose of 15 mg/kg on days 0, 1, 2, 3, 4 or 5. For comparison, three injections of 5 or 15 mg/kg on days 1-3 were administered. The ED(50) (dose at which ulceration is expected in 50% of the animals) for irradiation alone was 11.6 +/- 1.2 Gy. Mean latent time was 9.4 +/- 0.2 days; mean ulcer duration was 2.8 +/- 0.2 days. Single injections of rHuKGF did not result in a significant increase in isoeffective radiation doses at any of the administration days. However, the latent time to ulceration was significantly shortened by 1-2 days in all protocols. Repeated administration of rHuKGF (15 mg/kg) resulted a significant increase in ED50 to 16.8 +/- 4.0 Gy (P = 0.0047); the mean latent time was 4.4 +/- 0.9 days. Three injections of 5 mg/kg of Palifermin on days 1-3 yielded an ED50 of 19.4 +/- 1.7 Gy. In this protocol, mean latent time was 6.6 +/- 0.6 days. In conclusion, Palifermin has a potential to reduce the mucositis burden in patients after a single radiation exposure. Repeated injections are required. For three injections, a negative dose-effect of rHuKGF was observed. The optimum dose, number and timing of the administration require further investigation.

Palifermin Reduces Patient-Reported Mouth and Throat Soreness and Improves Patient Functioning in the Hematopoietic Stem-Cell Transplantation Setting

Purpose

To describe patient-reported outcomes of mouth and throat soreness (MTS) and related sequelae on daily activities from a phase III study of palifermin in the autologous hematopoietic stem-cell transplantation (HSCT) setting and to compare patient self-evaluations with clinicians' assessments of oral mucositis using objective scales.

Patients and Methods

Patients (n = 212) received palifermin (60 μg/kg/d) or placebo for 3 days before total-body irradiation (12 Gy), etoposide 60 mg/kg, and cyclophosphamide 100 mg/kg, and 3 days after HSCT. Patients completed a daily questionnaire (Oral Mucositis Daily Questionnaire [OMDQ]) evaluating MTS severity and its effects on daily functional activities. Patients' self-assessment data were compared with clinicians' assessments of oral mucositis using the objective scales.

Results

Palifermin reduced the incidence and duration of severe oral mucositis, as assessed by both clinicians and patients. Comparisons between patient and clinician assessments demonstrated that the average daily scores between mucositis grade and subjective (MTS) instruments were similar, although patients reported MTS onset, peak, and resolution earlier (1 to 3 days) than clinicians' assessments. Patients receiving palifermin reported statistically significant improvements (P < .001) in daily functioning activities (swallowing, drinking, eating, talking, sleeping) and required significantly less narcotic opioids (P < .001); improvement in the patient's overall physical and functional well-being was also reported. This was confirmed by the results of the Functional Assessment of Cancer Treatment questionnaire.

Conclusion

These results support the clinical benefit of palifermin in the HSCT setting, providing evidence that a patient's self-assessment instrument (OMDQ) may serve as an alternative tool to assess oral mucositis severity in clinical trials.

Palifermin Reduces the Incidence of Oral Mucositis in Patients With Metastatic Colorectal Cancer Treated With Fluorouracil-Based Chemotherapy

Purpose

To characterize the efficacy and safety of palifermin in reducing the incidence of oral mucositis (OM) and diarrhea when administered to patients with metastatic colorectal cancer (CRC) receiving fluorouracil/leucovorin (FU/LV) chemotherapy.

Patients and Methods

Patients (N = 64) were randomly assigned to receive either placebo or palifermin (40 μg/kg for 3 consecutive days) before each of two consecutive cycles of chemotherapy with FU/LV. The incidence of OM and diarrhea, safety, disease progression, and survival were evaluated.

Results

Thirty-six patients received placebo and 28 patients received palifermin. The incidence of WHO grade 2 or higher OM was lower in patients who received palifermin compared with placebo (29% v 61% in cycle 1; 11% v 47% in cycle 2). FU dose reductions in the second chemotherapy cycle were more frequent in the placebo group (31%) than in the palifermin group (14%). Investigators reported lower mucositis scores and patients reported less severe symptoms with palifermin. There were no statistically significant differences in the incidence or severity of diarrhea or in overall survival between the groups. Overall, palifermin was safe and well tolerated.

Conclusion

Palifermin administered at the indicated dosing regimen (40 μg/kg for 3 consecutive days) before chemotherapy was well tolerated and resulted in a statistically significant and clinically meaningful reduction in the incidence of WHO grade 2 or higher OM in patients with metastatic CRC.

Palifermin (recombinant keratinocyte growth factor-1): a pleiotropic growth factor with multiple biological activities in preventing chemotherapy- and radiotherapy-induced mucositis

Oral and intestinal mucositis are among the most significant dose-limiting toxic effects of intensive cancer treatment and are associated with adverse clinical and economic outcomes. Palifermin (Kepivancetrade mark), an N-truncated recombinant human keratinocyte growth factor-1, is the first agent to be approved for prevention of oral mucositis. Keratinocyte growth factor, a potent epithelial mitogen, appears to play a major role in the healing process. Palifermin has multiple biological activities that appear to protect the mucosal epithelium and promote its early regeneration after irradiation- and chemotherapy-induced injury. These include inhibition of epithelial cell apoptosis and DNA damage, up-regulation of detoxifying enzymes and down-regulation of pro-inflammatory cytokines, as well as enhanced migration, proliferation and differentiation of epithelial cells. Palifermin reduces the incidence, severity and duration of oral mucositis in patients with haematological malignancies undergoing myelotoxic conditioning therapy and haematopoietic stem-cell transplantation. Clinical sequelae, including febrile neutropenia and resource use (opioid analgesia and parenteral feeding), are concomitantly reduced. Other potential applications being explored include use in the solid tumour setting, reduction of intestinal mucositis and reduction of GVHD in allogenic transplantation. Thus, the development of palifermin and other potential new agents for preventing chemotherapy- and radiotherapy-induced mucositis represents an important breakthrough in oncological supportive care.

A protective role for keratinocyte growth factor in a murine model of chemotherapy and radiotherapy-induced mucositis

PURPOSE

To evaluate the activity of palifermin (rHuKGF) in a murine model of mucosal damage induced by a radiotherapy/chemotherapy (RT/CT) regimen mimicking treatment protocols used in head-and-neck cancer patients.

METHODS AND MATERIALS

A model of mucosal damage induced by RT/CT was established by injecting female BDF1 mice with cisplatin (10 mg/kg) on Day 1; 5-fluorouracil (40 mg/kg/day) on Days 1-4, and irradiation (5 Gy/day) to the head and neck on Days 1-5. Palifermin was administered subcutaneously on Days -2 to 0 (5 mg/kg/day) and on Day 5 (5 mg/kg). Evaluations included body weight, organ weight, keratinocyte growth factor receptor expression, epithelial thickness, and cellular proliferation.

RESULTS

Initiation of the radiochemotherapeutic regimen resulted in a reduction in body weight in control animals. Palifermin administration suppressed weight loss and resulted in increased organ weight (salivary glands and small intestine), epithelial thickness (esophagus and tongue), and cellular proliferation (tongue and salivary glands).

CONCLUSIONS

Administration of palifermin before RT/CT promotes cell proliferation and increases in epithelial thickness in the oral mucosa, salivary glands, and digestive tract. Palifermin administration before and after RT/CT mitigates weight loss and a trophic effect on the intestinal mucosa and salivary glands, suggesting that palifermin use should be investigated further in the RT/CT settings, in which intestinal mucositis and salivary gland dysfunction are predominant side effects of cytotoxic therapy.

Emerging approaches for prophylaxis and management of oropharyngeal mucositis in cancer therapy

Oral mucositis is a common treatment-limiting side effect of cancer therapy that may have a significant impact on quality of life and on the cost of care. Oral mucositis is the most distressing complication of cancer therapy as reported by head and neck cancer patients, in patients receiving dose-dense myelosuppressive chemotherapy and in patients receiving haematopoietic stem cell transplant. Mucositis may increase the risk of local and systemic infection, particularly in myelosuppressed patients. Severe oral mucositis can lead to the need to interrupt or discontinue cancer therapy, and thus may impact cure of the primary disease. Current care of patients with mucositis is essentially palliative, and includes appropriate oral hygiene, nonirritating diet and oral care products, topical palliative mouth rinses, topical anaesthetics and use of systemic opioid analgesics. Emerging approaches for prevention and treatment of oral mucositis are developing based on an increasing understanding of the pathobiology of mucosal damage and repair. New interventions are expected to be administered based on the mechanisms of initiation, progression and resolution of the condition. The approval by the FDA of keratinocyte growth factor (palifermin; Amgen) in 2004 represents a new step in prevention of oral mucositis in stem cell transplant patients based on the increasing understanding of the pathogenesis of mucositis. Progress in the prevention and management of mucositis will improve quality of life, reduce cost of care and facilitate completion of more intensive cancer chemotherapy and radiotherapy protocols. Improved management of mucositis may allow implementation of cancer treatment protocols that are currently excessively mucotoxic, but have potentially higher cure rates of the malignant disease.

Phase 1/2 randomized, placebo-control trial of palifermin to prevent graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (HSCT)

Palifermin, a recombinant human keratinocyte growth factor, was tested for potential benefits on acute graft-versus-host disease (GVHD) and hematopoietic recovery in allogeneic hematopoietic stem cell transplantation (HSCT) recipients. This randomized, double-blind, placebo-controlled, dose-escalation study assessed the safety and tolerability of palifermin (n = 69) as compared with placebo (n = 31) in patients conditioned with cyclophosphamide and fractionated total-body irradiation (Cy/TBI) or busulfan and cyclophosphamide (Bu/Cy) and given methotrexate along with a calcineurin inhibitor (cyclosporine A, tacrolimus) for GVHD prophylaxis. All patients received 3 doses before conditioning and either 3 (cohort 1), 6 (cohort 2), or 9 (cohort 3) doses after HSCT. Palifermin doses were 40 mug/kg per day (cohort 1 only) or 60 mug/kg per day (all cohorts). Six patients (placebo = 2, palifermin = 4) experienced a total of 11 dose-limiting toxicities (most often skin, respiratory, or oral mucositis). The most common adverse events included edema, infection, skin pain, or rash. Times to neutrophil and platelet engraftment were similar. No significant differences in acute GVHD incidence or severity, survival, or day 100 relapse rates were observed between groups. Palifermin was associated with reduced incidence and mean severity of mucositis in patients conditioned with Cy/TBI but not Bu/Cy. We conclude that palifermin was generally safe in allogeneic HSCTs but had no significant effect on engraftment, acute GVHD, or survival in this trial.

Keratinocyte growth factor expression and activity in cancer: implications for use in patients with solid tumors

Keratinocyte growth factor (KGF) is a locally acting epithelial mitogen that is produced by cells of mesenchymal origin and has an important role in protecting and repairing epithelial tissues. Use of recombinant human KGF (palifermin) in patients with hematologic malignancies reduces the incidence and duration of severe oral mucositis experienced after intensive chemoradiotherapy. These results suggest that KGF may be useful in the treatment of patients with other kinds of tumors, including those of epithelial origin. However, its application in this context raises issues that were not pertinent to its use in hematologic cancer because epithelial tumor cells, unlike blood cells, often express the KGF receptor (FGFR2b). Thus, it is important to examine whether KGF could promote the growth of epithelial tumors or protect such tumor cells from the effects of chemotherapy agents. Analyses of KGF and FGFR2b expression in tumor specimens and of KGF activity on transformed cells in vitro and in vivo do not indicate a definitive role for KGF in tumorigenesis. On the contrary, restoring FGFR2b expression to certain malignant cells can induce cell differentiation or apoptosis. However, other observations suggest that, in specific situations, KGF may contribute to epithelial tumorigenesis. Thus, further studies are warranted to examine the nature and extent of KGF involvement in these settings. In addition, clinical trials in patients with solid tumors are underway to assess the potential benefits of using KGF to protect normal tissue from the adverse effects of chemoradiotherapy and its possible impact on clinical outcome.

Palifermin for oral mucositis in the high-dose chemotherapy and stem cell transplant setting: the Royal Adelaide Hospital Cancer Centre experience

GOALS OF WORK

the aim of this paper was to review the initial use of Palifermin(rHu-KGF1) in a single institution, for the prevention of oral mucositis in high-dose chemotherapy and stem cell transplantation.

METHODS

the case records of the first five patients treated with Palifermin at the Royal Adelaide Hospital Cancer Centre were reviewed, and incidence,severity and duration of the oral mucositis were recorded, as well as demographics and toxicities.

RESULTS

two of the five patients developed grade 4 mucositis, and the remaining three patients developed grade 2 mucositis. Palifemin was well tolerated with only one patient developing a rash.

CONCLUSIONS

the severity of oral mucositis was less than would be expected in these patients without anti-mucositis therapy. Palifermin was well tolerated. Obviously this single institution report is from a very small cohort of patients, but it is encouraging for the ease of use of this drug in the future.

Biomimetic delivery of keratinocyte growth factor upon cellular demand for accelerated wound healing in vitro and in vivo

Exogenous keratinocyte growth factor (KGF) significantly enhances wound healing, but its use is hampered by a short biological half-life and lack of tissue selectivity. We used a biomimetic approach to achieve cell-controlled delivery of KGF by covalently attaching a fluorescent matrix-binding peptide that contained two domains: one recognized by factor XIII and the other by plasmin. Modified KGF was incorporated into the fibrin matrix at high concentration in a factor XIII-dependent manner. Cell-mediated activation of plasminogen to plasmin degraded the fibrin matrix and cleaved the peptides, releasing active KGF to the local microenvironment and enhancing epithelial cell proliferation and migration. To demonstrate in vivo effectiveness, we used a hybrid model of wound healing that involved transplanting human bioengineered skin onto athymic mice. At 6 weeks after grafting, the transplanted tissues underwent full thickness wounding and treatment with fibrin gels containing bound KGF. In contrast to topical KGF, fibrin-bound KGF persisted in the wounds for several days and was released gradually, resulting in significantly enhanced wound closure. A fibrinolytic inhibitor prevented this healing, indicating the requirement for cell-mediated fibrin degradation to release KGF. In conclusion, this biomimetic approach of localized, cell-controlled delivery of growth factors may accelerate healing of large full-thickness wounds and chronic wounds that are notoriously difficult to heal.