Drug safety in thalassemia: lessons from the present and directions for the future.

Introduction: Beta-thalassemia is an autosomal recessive hereditary anemia characterized by reduced or absent ß-globin chain synthesis, affecting about 60,000 people peryear. Management for ß-thalassemia major includes regular blood transfusions followed by iron chelating therapy and drug targeting ineffective erythropoiesis.Areas covered: The safety of licensed drugs for the management of ß-thalassemia is reviewed, using evidence from clinical trials and observational research. Such drugs include the iron chelators and the erythrocyte maturation agent luspatercept. The safety of emerging treatment, such as hydroxyurea and thalidomide is also reviewed.Expert opinion: Beta-thalassemia is arare disease, and is not surprising that there are limited studies investigating the safety of drugs used in this disease. Indeed, although observational studies are the main source of drug safety information in areal-world setting, only eleven studies were identified for iron-chelators and none of these estimated the risk of agiven safety outcome. Future work should aim to better leverage existing sources of real-world datato investigate drug safety in thalassemia.

Naja sputatrix Venom Preconditioning Attenuates Neuroinflammation in a Rat Model of Surgical Brain Injury via PLA2/5-LOX/LTB4 Cascade Activation.

Inflammatory preconditioning is a mechanism in which exposure to small doses of inflammatory stimuli prepares the body against future massive insult by activating endogenous protective responses. Phospholipase A2/5-lipoxygenase/leukotriene-B4 (PLA2/5-LOX/LTB4) axis is an important inflammatory signaling pathway. Naja sputatrix (Malayan spitting cobra) venom contains 15% secretory PLA2 of its dry weight. We investigated if Naja sputatrix venom preconditioning (VPC) reduces surgical brain injury (SBI)-induced neuroinflammation via activating PLA2/5-LOX/LTB4 cascade using a partial frontal lobe resection SBI rat model. Naja sputatrix venom sublethal dose was injected subcutaneously for 3 consecutive days prior to SBI. We observed that VPC reduced brain edema and improved neurological function 24 h and 72 h after SBI. The expression of pro-inflammatory mediators in peri-resection brain tissue was reduced with VPC. Administration of Manoalide, a PLA2 inhibitor or Zileuton, a 5-LOX inhibitor with VPC reversed the protective effects of VPC against neuroinflammation. The current VPC regime induced local skin inflammatory reaction limited to subcutaneous injection site and elicited no other toxic effects. Our findings suggest that VPC reduces neuroinflammation and improves outcomes after SBI by activating PLA2/5-LOX/LTB4 cascade. VPC may be beneficial to reduce post-operative neuroinflammatory complications after brain surgeries.

Critical Reviews: How we treat sickle cell patients with leg ulcers.

The past five decades have seen an improvement in the mortality and morbidity of sickle cell disease (SCD) because of prophylaxis against infectious complications, improved and expanded red cell transfusions, implementation of hydroxyurea therapy, and advances in supportive care. Now that the majority of patients in the western hemisphere reaches adulthood, end organ diseases are frequent, which include vasculopathic complications such as chronic leg ulcers. The management of patients with leg ulcers requires the hematologist to lead a team of health care professionals, and investigates the presence of associated, but potentially still occult signs of vasculopathy, such as pulmonary hypertension, renal disease, priapism and retinopathy. These complications may be asynchronous, and long term careful screening is indicated, in order to ensure early diagnosis and intervention. It is crucial to address both the immediate consequences of pain, infection and disability, and long term effects on quality of life, employment and stigma associated with chronic ulceration. Recent insights into their pathophysiology may have practical implications. We propose a holistic approach to the management of patients' physical and emotional problems and mechanisms of ulcers formation and delayed healing. An overview of topical and systemic therapies for chronic ulcers is given, with the understanding that wound care therapy is best left to the wound specialists, medical and surgical, with whom the hematologist must keep an open line of communication. In the absence of evidence-based guidelines, our opinion is based on both a critical review of the literature and our personal clinical and research experience.

Age most significant predictor of requiring enteral feeding in head-and-neck cancer patients.

BACKGROUND: A significant number of patients treated for head and neck squamous cell cancer (HNSCC) undergo enteral tube feeding. Data suggest that avoiding enteral feeding can prevent long-term tube dependence and disuse of the swallowing mechanism which has been linked to complications such as prolonged dysphagia and esophageal constriction. We examined detailed dosimetric and clinical parameters to better identify those at risk of requiring enteral feeding. METHODS: One hundred patients with advanced stage HNSCC were retrospectively analyzed after intensity-modulated radiation therapy (IMRT) to a median dose of 70 Gy (range: 60-75 Gy) with concurrent chemotherapy in nearly all cases (97%). Patients with significant weight loss (>10%) in the setting of severely reduced oral intake were referred for placement of a percutaneous endoscopic gastrostomy (PEG) tube. Detailed DVH parameters were collected for several structures. Univariate and multivariate analyses using logistic regression were used to determine clinical and dosimetric factors associated with needing enteral feeding. Dichotomous outcomes were tested using Fisher's exact test and continuous variables between groups using the Wilcoxon rank-sum test. RESULTS: Thirty-three percent of patients required placement of an enteral feeding tube. The median time to tube placement was 25 days from start of treatment, after a median dose of 38 Gy. On univariate analysis, age (p=0.0008), the DFH (Docetaxel/5-FU/Hydroxyurea) chemotherapy regimen (p= .042) and b.i.d treatment (P=0.040) (used in limited cases on protocol) predicted need for enteral feeding. On multivariate analysis, age remained the single statistically significant factor (p=0.003) regardless of other clinical features (e.g. BMI) and all radiation planning parameters. For patients 60 or older compared to younger adults, the odds ratio for needing enteral feeding was 4.188 (p=0.0019). CONCLUSIONS: Older age was found to be the most significant risk factor for needing enteral feeding in patients with locally advanced HNSCC treated with multimodal treatment. Pending further validation, this would support maximizing early nutritional guidance, targeted supplementation, and symptomatic support for older adults (>60) undergoing chemoradiation. Such interventions and others (e.g. swallowing therapy) could possibly delay or minimize the use of enteral feeding, thereby helping avoid tube dependence and tube-associated long-term physiologic consequences.

Efficacy and safety of deferasirox compared with deferoxamine in sickle cell disease: two-year results including pharmacokinetics and concomitant hydroxyurea.

We report a prospective, randomized, Phase II study of deferasirox and deferoxamine (DFO) in sickle cell disease patients with transfusional iron overload, with all patients continuing on deferasirox after 24 weeks, for up to 2 years. The primary objective was to evaluate deferasirox safety compared with DFO; long-term efficacy and safety of deferasirox was also assessed. We also report, for the first time, the safety and pharmacokinetics of deferasirox in patients concomitantly receiving hydroxyurea. Deferasirox (n = 135) and DFO (n = 68) had comparable safety profiles over 24 weeks. Adverse events (AEs) secondary to drug administration were reported in 26.7% of patients in the deferasirox cohort and 28.6% in the DFO cohort. Gastrointestinal disorders were more common with deferasirox, including diarrhea (10.4% versus 3.6%) and nausea (5.2% versus 3.6%). The most common AE in the DFO group was injection-site pain irritation, which occurred in 7% of patients. Acute renal failure occurred in one patient on deferasirox who was continued on medication despite progressive impairment of renal function parameters. Serum ferritin levels were reduced in both treatment groups. Patients continuing on deferasirox for up to 2 years demonstrated an absolute median serum ferritin decrease of -614 ng/mL (n = 96). Increasing deferasirox dose was associated with improved response and a continued manageable safety profile. Concomitant hydroxyurea administration (n = 28) did not appear to influence the efficacy, safety (including liver and kidney function), and pharmacokinetic parameters of deferasirox.

Outcomes of induction chemotherapy followed by concurrent chemoradiation for nasopharyngeal carcinoma.

PURPOSE: Current standard therapy for nasopharyngeal carcinoma (NPC) is concurrent chemoradiation based on randomized data. However, limited randomized data exist to support the addition of induction chemotherapy (ICT). METHODS: 58 Patients with NPC were treated from 1990 to 2010. All patients received platinum-based ICT. All 58 patients were treated with chemoradiation, 57 in a week-on/week-off (WOWO) fashion. Concurrent chemotherapy included hydroxyurea/5-fluorouracil for all patients. Median radiation dose was 70 Gy. No patient received adjuvant chemotherapy. RESULTS: AJCC 2009 stage was II=13, III=21, IVa=13, and IVb=11. Median follow-up for surviving patients was 66 months. Response to ICT was complete response (CR) 17% and partial response (PR) 64%. The CR rate after chemoradiation was 96%. Five-year actuarial freedom from local failure (FFLF), freedom from distant failure (FFDF), cause-specific survival (CSS), and overall survival (OS) was 98%, 90%, 90%, and 76%, respectively. Analysis of pediatric patients (n=9) demonstrated 5-year actuarial FFLF, FFDF, CSS, and OS of 100%, 88%, 80%, and 80%, respectively. CONCLUSIONS: ICT followed by concurrent chemoradiation demonstrates excellent FFLF, FFDF, CSS, and OS with tolerable toxicity. Induction chemotherapy followed by concurrent chemoradiation for patients with NPC should be explored further in a randomized setting.

Hydroxyurea: a key player in cancer chemotherapy.

Hydroxyurea (HU) is a simple organic compound currently used as a cancer chemotherapeutic agent. It acts specifically on the S-phase of the cell cycle by inhibiting the enzyme ribonucleoside diphosphate reductase, thereby hindering the reductive conversion of ribonucleotides to deoxyribonucleotides and thus limiting de novo DNA synthesis. HU is employed in hemotological settings as a first-line treatment of myeloproliferative disorders, such as polycythemia vera, essential thrombocythemia and primary myelofibrosis, apart from having a vital role in combination therapy for management of malignant melanoma, head and neck cancers and brain tumors. It offers an advantage that the patient may take this drug on an ambulatory basis with minimum clinical toxicity, while some of its limitations include gastrointestinal disturbance and bone marrow depression. This review will summarize and present the overall effects of HU and its combination therapy as an anticancer agent.

Adjuvant chemoradiotherapy for locoregionally advanced and high-risk salivary gland malignancies.

BACKGROUND: To report the outcomes of patients with locoregionally advanced and high- risk salivary gland malignancies treated with surgery followed by adjuvant chemoradiotherapy. METHODS: From 09/1991 - 06/2007, 24 high-risk salivary gland cancer patients were treated with surgery, followed by adjuvant chemoradiotherapy for high-risk pathologic features including, perineural involvement, nodal involvement, positive margins, or T3/T4 tumors. Chemoradiotherapy was delivered for 4-6 alternating week cycles: the most common regimen, TFHX, consisted of 5 days paclitaxel (100 mg/m² on d1), infusional 5-fluorouracil (600 mg/m²/d × 5d), hydroxyurea (500 mg PO BID), and 1.5 Gy twice daily irradiation followed by a 9-day break without treatment. RESULTS: Median follow-up was 42 months. The parotid gland was more frequently involved (n = 17) than minor (n = 4) or submandibular (n = 3) glands. The median radiation dose was 65 Gy (range 55-68 Gy). Acute treatment related toxicity included 46% grade 3 mucositis and 33% grade 3 hematologic toxicity. Six patients required feeding tubes during treatment. One patient progressed locally, 8 patients progressed distantly, and none progressed regionally. Five-year locoregional progression free survival was 96%. The 3 and 5 year overall survival was 79% and 59%, respectively. Long-term complications included persistent xerostomia (n = 5), esophageal stricture requiring dilatation (n = 1), and tempromandibular joint syndrome (n = 1). CONCLUSIONS: Surgical resection followed by adjuvant chemoradiotherapy results in promising locoregional control for high-risk salivary malignancy patients.

Antiviral hyperactivation-limiting therapeutics as a novel class for the treatment of HIV/AIDS: focus on VS411.

INTRODUCTION: Immune activation plays a central pathogenetic role in both HIV-1 replication and depletion of CD4(+) T cells leading to disease progression and the onset of the AIDS. While current antiretroviral therapies suppress viral replication to undetectable levels, they do not normalize the excessive level of T-cell activation and proliferation. A new class of anti-HIV-1 drugs known as antiviral hyperactivation-limiting therapeutics (AV-HALTs) combines direct antiviral activity with an antiproliferative action to limit the hyperactivation of the immune system now recognized as the key driver of the progressive loss of CD4(+) T cells that occurs over the natural course of the HIV-1 infection. AREAS COVERED: Areas covered include preclinical, Phase I and Phase IIa studies of VS411, the first drug product in a novel class of anti-HIV drugs, AV-HALT agents. EXPERT OPINION: The two drug combination VS411 safely achieved the goals established for the AV-HALT class based on the results of a Phase IIA proof-of-concept study. Additional work is underway to identify and develop new agents that combine the dual attributes of AV-HALTs, direct reduction of both HIV-1 viral load and markers of excessive immune activation, in a single molecule.

Chemoradiotherapy for locoregionally advanced squamous cell carcinoma of the base of tongue.

BACKGROUND: Our aim was to report the outcomes of base of tongue cancers treated with chemoradiotherapy. METHODS: Between 1990 and 2004, 127 patients with stage III or IV base of tongue cancer were treated with chemoradiotherapy on protocol. Indications included nodal involvement, T3/T4 tumors, positive margins, those patients refusing surgery, or were medically inoperable. The most common regimen was paclitaxel (100 mg/m2 on day 1), infusional 5-fluorouracil (600 mg/m2/day × 5 days), hydroxyurea (500 mg prescribed orally [PO] 2 × daily [BID]), and 1.5 Gy twice daily irradiation followed by a 9-day break without treatment. RESULTS: Median follow-up was 51 months. The median dose to gross tumor was 72.5 Gy (range, 40-75.5 Gy). Five-year locoregional progression-free survival, overall survival, and disease-free survival was 87.0%, 58.2%, and 46.0%, respectively. CONCLUSION: Concurrent chemoradiotherapy results in promising locoregional control for base of tongue cancer. As distant relapse was common, further investigation of systemic therapy with novel agents may be warranted.

Increase in brain tumor permeability in glioma-bearing rats with nitric oxide donors.

PURPOSE: The blood-brain tumor barrier (BTB) significantly limits the delivery of chemotherapeutics to brain tumors. Nitric oxide (NO) is involved in the regulation of cerebral vascular permeability. We investigated the effects of NO donors, L-arginine and hydroxyurea, on BTB permeability in 9L gliosarcoma-bearing Fischer rats. EXPERIMENTAL DESIGN: The rats implanted with 9L gliosarcoma were dosed orally with hydroxyurea and L-arginine. BTB permeability, defined by the unidirectional transport constant, Ki, for [14C]sucrose was measured. The expression of neural and endothelial NO synthase (NOS) in tumors and normal brain tissue was examined. Further, the levels of NO, L-citrulline, and cGMP in the tumor and normal brain tissue were measured. RESULTS: Oral administration of l-arginine or hydroxyurea significantly increased BTB permeability when compared with the nontreated control. The selective effects were abolished by iberiotoxin, an antagonist of calcium-dependent potassium (KCa) channel that is a cGMP pathway effector. The expression of endothelial NOS, but not neural NOS, was higher in tumor vessels than in those of normal brain. Moreover, the levels of NO, L-citrulline, a byproduct of NO formation from L-arginine, and cGMP were enhanced in the tumor tissue by oral administration of L-arginine and/or hydroxyurea. CONCLUSIONS: Oral administration of L-arginine or hydroxyurea selectively increased tumor permeability, which is likely mediated by alteration in cGMP levels. The findings suggest that use of oral NO donors may be a strategy to enhance the delivery of chemotherapeutics to malignant brain tumors.

Final report of RTOG 9610, a multi-institutional trial of reirradiation and chemotherapy for unresectable recurrent squamous cell carcinoma of the head and neck.

BACKGROUND: Our objectives were to determine the incidence of acute and late toxicities and to estimate the 2-year overall survival for patients treated with reirradiation and chemotherapy for unresectable squamous cell carcinoma of the head and neck (SCCHN). METHODS: Patients with recurrent squamous cell carcinoma or a second primary arising in a previously irradiated field were eligible. Four weekly cycles of 5-fluorouracil 300 mg/m2 IV bolus and hydroxyurea 1.5 g by mouth were used with 60 Gy at 1.5 Gy twice-daily fractions. Toxicity was scored according to Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer (RTOG/EORTC) criteria. RESULTS: Seventy-nine of the 86 patients enrolled were analyzable. The worst acute toxicity was grade 4 in 17.7% and grade 5 in 7.6%. Grade 3 and 4 late toxicities were found in 19.4% and 3.0%, respectively. The estimated cumulative incidence of grade 3 to 4 late effects occurring at >1 year was 9.4% (95% confidence interval [CI]: 0, 19.7) at 2 and 5 years. The 2- and 5-year cumulative incidence for grade 4 toxicity was 3.1% (95% CI: 0, 9.3). The estimated 2- and 5-year survival rates were 15.2% (95% CI: 7.3, 23.1) and 3.8% (95% CI: 0.8, 8.0), respectively. Patients who entered the study at >1 year from initial radiotherapy (RT) had better survival than did those who were <1 year from prior RT (median survival, 9.8 months vs 5.8 months; p = .036). No correlation was detected between dose received and overall survival. Three patients were alive at 5 years. CONCLUSION: This is the first prospective multi-institutional trial testing reirradiation plus chemotherapy for recurrent or second SCCHN. The approach is feasible with acceptable acute and late effects. The results serve as a benchmark for ongoing RTOG trials.

Calcium channel antagonists augment hydroxyurea- and ru486-induced inhibition of meningioma growth in vivo and in vitro.

OBJECTIVE: Although the chemotherapy drug hydroxyurea (HU) and the antiprogesterone mifepristone (RU486) have been used to treat meningiomas for which surgical and radiation therapies have failed, results have been disappointing. The addition of calcium channel antagonists (CCAs) to chemotherapeutic drugs enhances tumor growth inhibition in other tumor types, and the authors demonstrated that CCAs can block meningioma growth in vitro and in vivo. The purpose of this study was to test the effects of the addition of a CCA to HU or RU486 on meningioma growth. METHODS: Primary and malignant (IOMM-Lee) meningioma cell lines were treated with HU, RU486, or either of these plus diltiazem or verapamil. Assays for cell growth, apoptosis, and fluorescent-activated cell sorting were performed on in vitro cultures. Similar cell lines were implanted into nude mice and were treated with HU or RU486, in combination with a CCA. Tumors were analyzed by light microscopy, MIB-1, and factor VIII immunohistochemical staining studies. RESULTS: The addition of diltiazem or verapamil to HU or RU486 augmented meningioma growth inhibition by 20 to 60% in vitro. In vivo, tumors treated with combination drugs were smaller; and immunohistochemical analysis of the IOMM-Lee tumors showed a 10% decrease in the MIB-1 ratio (from 0.41 to 0.30) and an approximate 75% decrease in microvascular density. CONCLUSION: The addition of diltiazem or verapamil to HU or RU486 augments meningioma growth inhibition in vitro by inducing apoptosis and G1 cell-cycle arrest. The combination of HU and diltiazem inhibited the growth of meningiomas in vivo by decreasing proliferation and microvascular density. These results suggest a possible role for these drugs as an additional adjuvant therapy for recurrent or unresectable meningiomas.

High survival and organ function rates after primary chemoradiotherapy for intermediate-stage squamous cell carcinoma of the head and neck treated in a multicenter phase II trial.

PURPOSE: Patients with intermediate-stage squamous cell carcinoma of the head and neck traditionally have been treated with initial surgical resection followed by radiotherapy (RT) alone or chemoradiotherapy. A previous study in this patient population reported a 91% locoregional control rate and 65% overall survival (OS) rate at 5 years, with chemoradiotherapy used as primary treatment. This study was undertaken to assess whether shortening treatment duration with hyperfractionated RT would be feasible and improve locoregional control, organ preservation, and progression-free survival. METHODS: Eligible patients with stage II or III disease received fluorouracil, hydroxyurea, and RT given twice daily on a week-on/week-off schedule. Quality-of-life scores were measured using three validated indexes. RESULTS: All 53 patients enrolled are included in the analysis, with a median follow-up of 42 months (range, 5 to 98 months). Grade 3 or 4 in-field mucositis was observed in 77% and 9%, respectively. No patients required surgical salvage at the primary tumor site (pathological complete response rate, 100%). The 3-year progression-free and OS rates are 67% and 78%, respectively. The 3-year disease-specific mortality rate is 7%. At the time of analysis, 87% of surviving patients do not require enteral feeding support. Quality-of-life and performance assessment indicated that, although acute treatment toxicities were severe, most patients returned to pretreatment function by 12 months. CONCLUSION: Concurrent chemoradiotherapy with hyperfractionated RT is feasible in this patient population and yields high local control and cure rates. Compared with our historical control using once-daily fractionation, hyperfractionation is accompanied by increased acute in-field toxicity.

Bone marrow transplantation in adults with thalassemia: Treatment and long-term follow-up.

Current regular blood transfusion programs and chelation treatment have considerably improved survival of patients with thalassemia, which resulted in a larger proportion of adult patients. However, disease- and treatment-related complications in these patients progress over time, causing severe morbidity and shortened life expectancy. Stem cell transplantation still remains the only cure currently available for patients with thalassemia. This study updates transplant outcomes in 107 adult patients with median age of 22 years (range, 17-35 years) who received bone marrow transplantation (BMT) from human leukocyte antigen (HLA)-identical related donors between 1988 and 1996 (group A) and describes the results of BMT in 15 adult patients with median age of 21 years (range, 17-31 years) who were treated with a new treatment protocol (Protocol 26) between 1997 and 2003 (group B). The probability of survival, event-free survival, nonrejection mortality, and rejection for group A patients were 66%, 62%, 37%, and 4%, respectively, with a median follow-up of 12 years (range, 8.3-16.2 years). Group B patients treated with the new protocol had some improvement in thalassemia-free survival (67%) and lower transplant-related mortality (27%) than that of previous protocols. However, transplant-related mortality in these high-risk patients remains elevated. Current myeloablative BMT in adult patients is characterized by higher transplant-related toxicity due to an advanced phase of disease. Although this new approach to transplant adult patients with a reduced-dose intensity-conditioning regimen has improved thalassemia-free survival, transplant-related mortality in these high-risk patients remains elevated.

Phase II clinical trial of parenteral hydroxyurea in combination with fluorouracil, interferon and filgrastim in the treatment of advanced pancreatic, gastric and neuroendocrine tumors.

PURPOSE: Combined inhibition of ribonucleotide reductase (RR) and thymidylate synthase (TS), the enzymes responsible for a balanced supply of nucleotides for DNA synthesis, has been shown to induce synergistic antiproliferative effects in vitro. In the clinic, prolonged infusion of the RR inhibitor, hydroxyurea (HU), may be more effective than bolus or oral administration of drug. The purpose of the current study was to determine whether dose intensification of parenteral hydroxyurea in combination with fluorouracil could enhance the response rates of the combination against refractory upper gastrointestinal malignancies. METHODS: A clinical trial of parenteral, weekly, high-dose HU in combination with weekly, high-dose infusional fluorouracil (5FU) was initiated in patients with advanced pancreatic and gastric cancer. Patients received 5FU 1.3 g/m(2) by continuous intravenous infusion (CIVI) daily over 48 h weekly in combination with HU 4.3 g/m(2) CIVI per day over 48 h weekly. Patients also received the biologic agent interferon alfa-2a 9 MU subcutaneously (s.c.) three times per week and filgrastim 480 microg s.c. on days 3 (starting after midday), 4, 5, and 6 each week. Each cycle required treatment on days 1 and 8 every 22 days. RESULTS: Enrolled in the study were 32 patients, of whom 30 were evaluable. The median age was 56 years. Primary sites included pancreas (18), gastric (13) and islet cell (1). Despite filgrastim, the major toxicities were hematologic with 15 of 30 patients developing grade 3/4 granulocytopenia. Of the 30 patients, 4 developed grade 3/4 diarrhea. Interferon-mediated fatigue was mild. Of 12 evaluable patients with gastric cancer, 1 had a partial response, and there were no responders among patients with pancreatic cancer. CONCLUSIONS: Combined inhibition of RR and TS using this high-dose, weekly, 48-h infusional regimen is not an improvement over single-agent therapy in these tumor types.

Intensive concurrent chemoradiotherapy for head and neck cancer with 5-Fluorouracil- and hydroxyurea-based regimens: reversing a pattern of failure.

Combined modality programs that were developed over the past two decades demonstrated that the nonsurgical therapy of locoregionally advanced head and neck cancer is feasible and produces survival outcomes that are at least comparable with surgery. The systemic therapy of head and neck cancer has gained momentum in recent years. Several randomized studies have shown that the concurrent administration of chemotherapy and radiation therapy is superior to radiation therapy alone. In consecutive clinical studies since 1986, we have developed multiagent chemoradiotherapy regimens based on initial observations with the 5-fluorouracil (5-FU), hydroxyurea, and concomitant radiotherapy combination. Three consecutive multicenter phase II trials reported that the combination of 5-FU and hydroxyurea with either cisplatin or paclitaxel along with twice daily radiation therapy administered every other week is a highly effective regimen with local control rates that approach 90% and 3-year survival rates of approximately 60% in patients with stage IV disease. The vast majority of patients in these studies achieved anatomical organ preservation. A reversal of the historical pattern of failure was evident, with distant sites becoming the predominant site of failure in each trial. The paclitaxel-containing regimen was better tolerated than the cisplatin-containing regimen and was advanced to further clinical testing. The incorporation of induction chemotherapy may improve the results of treatment by targeting systemic micrometastatic disease.

Hydroxyurea and arginine therapy: impact on nitric oxide production in sickle cell disease.

PURPOSE: Recent data suggest that hydroxyurea (HU) increases the production of nitric oxide (NO), a potent vasodilator. NO is normally metabolized from l-Arginine (Arg). However, in vitro and animal experiments suggest that HU is the NO donor itself. In contrast, a recent study indicates that nitric oxide synthase (NOS) may play a role. Since adults with sickle cell disease (SCD) are Arg-deficient, Arg availability may limit the ability of HU to maximally impact NO production if an NOS mechanism is involved. The authors have previously shown that Arg supplementation alone induces a paradoxical decrease in NO metabolite (NO(x)) production. METHODS: The authors studied the effects of HU and Arg supplementation on NO(x) production. HU alone or HU + Arg was administered to patients with SCD at steady state, and sequential levels of Arg, serum NO(x) and exhaled NO were followed over 4 hours. RESULTS: After HU + Arg, all patients demonstrated a significant increase in serum NO(x) production within 2 hours. When the same patients were treated with HU alone (5.1 +/- 2 micromol/L), a mixed response occurred. NO(x) levels increased in four patients and decreased in one patient (-23.3 micromol/L). CONCLUSIONS: While Arg alone does not increase serum NO(x) production in SCD patients at steady state, it does when given together with HU. Hence, co-administration of Arg with HU may augment the NO(x) response in SCD and improve utilization of Arg in patients at steady state.

A randomized study comparing interferon (IFN alpha) plus low-dose cytarabine and interferon plus hydroxyurea (HU) in early chronic-phase chronic myeloid leukemia (CML).

This multicenter randomized phase III study was designed to compare the efficacy and toxicity of IFN alpha-2c (3.5 MU/d) in combination with either araC (10 mg/m(2) d1-10) or hydroxyurea (HU: 25 mg/kg per day) in newly diagnosed CML patients. A total of 114 patients were randomized. Following a median observation period of 36 (range 1-73) months the major cytogenetic response rates were 25 and 27% and the 4-year survival probabilities 62.5 and 63% for the araC and HU group, respectively. While the overall toxicity profile was comparable between both groups, patients in the HU arm exhibited a slightly higher degree of WHO grades 3 and 4 non-hematological toxicities.