Melphalan induced germ cell toxicity and dose-dependent effects of ß-aminoisobutyric acid in experimental rat model: Role of oxidative stress, inflammation and apoptosis.

The success of chemotherapy regimens has led to an increase in cancer survival rate over the last decades. Melphalan has been widely used for the treatment of several types of cancers despite its gonadotoxic effects. Due to its ability to cause mutations in the spermatogonial stem cells and spermatids, melphalan can exert a negative impact on male reproductive health in young cancer survivors. ß-aminoisobutyric acid (BAIBA), a myokine released by skeletal muscles, has been reported to have beneficial effects in diabetic nephropathy, cardiomyopathy and hepatic toxicity. However, the exact role of BAIBA in chemotherapy-induced germ cell toxicity is still unexplored. The present study aims to determine the dose-dependent (25, 50, and 100 mg/kg) effects of BAIBA on melphalan-induced (1.5 mg/kg) germ cell toxicity in sprague-dawley (SD) rats. The evaluation parameters included quantification of oxidative stress biomarkers, sperm count, sperm motility and head morphology, sperm and testicular DNA damage, sperm mitochondrial membrane potential, ultrastructural changes in sperms, histological and protein expression studies in testes. Melphalan treatment significantly altered all the above-mentioned parameters and the high dose (100 mg/kg) of BAIBA restored melphalan-induced toxicity in a significant manner by exerting antioxidant, anti-inflammatory and antiapoptotic effects. However, the medium dose (50 mg/kg) of BAIBA decreased the toxicity of melphalan and the low dose (25 mg/kg) of BAIBA failed to counteract the melphalan-induced male germ cell toxicity as well as the peripheral blood micronucleus induction. The antioxidant, anti-inflammatory and antiapoptotic role of BAIBA in melphalan-induced gonadal damage is a novel finding in an experimental rat model.

Juvenile exposure and adult risk assessment with single versus repeated exposure of melphalan in the germ cells of male SD rat: Deciphering the molecular mechanisms.

Melphalan significantly contributes to the increase in childhood cancer survival rate. It acts as a gonadotoxic agent and leads to testes damage, dysbalance in gonadal hormones, and impairment in the germ cell proliferation. Therefore, it might be a potent threat to male fertility in individuals who have undergone melphalan treatment during childhood cancer. However, the molecular mechanisms of melphalan-induced gonadal damage are not yet fully explored and they need to be investigated to determine the benefit-risk profile. In the present study, juvenile male SD rats were subjected to single and intermittent cycles of melphalan exposure in a dose-dependent (0.375, 0.75 and 1.5 mg/kg) manner. Methods of end-points evaluations were quantification of micronuclei formation in peripheral blood, sperm count, sperm motility and head morphology, sperm and testicular DNA damage, histological studies in testes, oxidative/nitrosative stress parameters. A single cycle of exposure at high dose (1.5 mg/kg) produced significant effect on micronuclei formation only after the first week of exposure, whereas failed to produce significant effect at the end of the sixth week. Intermittent cycles of exposure at the dose of 1.5 mg/kg produced significant alterations in all the parameters (micronuclei in peripheral blood, testes and epididymides weight and length, MDA, GSH and nitrite levels, sperm count and motility, sperm head morphology, testicular and sperm DNA damage, protein expression in testes and histological parameters). So, time of exposure as well as the amount of exposure (total dosage administered) is critical in determining the magnitude of the damage in germ cell risk assessment.

Evaluation of intravitreal topotecan dose levels, toxicity and efficacy for retinoblastoma vitreous seeds: a preclinical and clinical study.

BACKGROUND: Current melphalan-based intravitreal regimens for retinoblastoma (RB) vitreous seeds cause retinal toxicity. We assessed the efficacy and toxicity of topotecan monotherapy compared with melphalan in our rabbit model and patient cohort. METHODS: Rabbit experiments: empiric pharmacokinetics were determined following topotecan injection. For topotecan (15 µg or 30 µg), melphalan (12.5 µg) or saline, toxicity was evaluated by serial electroretinography (ERG) and histopathology, and efficacy against vitreous seed xenografts was measured by tumour cell reduction and apoptosis induction. PATIENTS: retrospective cohort study of 235 patients receiving 990 intravitreal injections of topotecan or melphalan. RESULTS: Intravitreal topotecan 30 µg (equals 60 µg in humans) achieved the IC90 across the rabbit vitreous. Three weekly topotecan injections (either 15 µg or 30 µg) caused no retinal toxicity in rabbits, whereas melphalan 12.5 µg (equals 25 µg in humans) reduced ERG amplitudes 42%-79%. Intravitreal topotecan 15 µg was equally effective to melphalan to treat WERI-Rb1 cell xenografts in rabbits (96% reduction for topotecan vs saline (p=0.004), 88% reduction for melphalan vs saline (p=0.004), topotecan vs melphalan, p=0.15). In our clinical study, patients received 881 monotherapy injections (48 topotecan, 833 melphalan). Patients receiving 20 µg or 30 µg topotecan demonstrated no significant ERG reductions; melphalan caused ERG reductions of 7.6 µV for every injection of 25 µg (p=0.03) or 30 µg (p<0.001). Most patients treated with intravitreal topotecan also received intravitreal melphalan at some point during their treatment course. Among those eyes treated exclusively with topotecan monotherapy, all eyes were salvaged. CONCLUSIONS: Taken together, these experiments suggest that intravitreal topotecan monotherapy for the treatment of RB vitreous seeds is non-toxic and effective.

Toxicity assessment of concurrent gabapentin/pregabalin administration with high-dose melphalan in autologous hematopoietic cell transplant recipients.

A theoretical pharmacokinetic interaction mediated through L-amino acid transporter 1 and 2 exists between gabapentin (GP) and pregabalin (PG) with melphalan. Peripheral neuropathy is a common toxicity of various multiple myeloma regimens commonly utilized prior to autologous hematopoietic cell transplant (auto-HCT) with high-dose melphalan (HD-Mel). Therefore, it is likely concurrent administration of either GP or PG will occur in patients receiving HD-Mel conditioning for auto-HCT, which could potentially increase cellular uptake and worsen the mucosal injury. A retrospective chart review of adult patients from January 2012 to July 2016 who received HD-Mel (140-200 mg/m2) at West Virginia University Medicine was performed to assess toxicity and outcomes in these patients. A total of 80 patients were included in the study, with 30 patients receiving GP or PG and 50 control patients. There were no significant differences in grade 2 or higher mucositis, admissions for nausea/vomiting/diarrhea, intravenous opioid requirements, oral topical therapies, antidiarrheal medication use, rescue anti-emetics, days of nausea or vomiting, pain scores, neutrophil or platelet engraftment, treatment-related mortality, progression-free survival, or overall survival. Our data suggest that it is safe to continue GP/PG therapy throughout HD-Mel therapy, with no negative transplant outcomes. Prospective studies or evaluations of larger databases are necessary to better characterize the clinical effect of concomitant therapy.

Intravitreal melphalan hydrochloride vs propylene glycol-free melphalan for retinoblastoma vitreous seeds: Efficacy, toxicity and stability in rabbits models and patients.

The use of intravitreal chemotherapy has revolutionized the treatment of advanced intraocular retinoblastoma, as intravitreal melphalan has enabled difficult-to-treat vitreous tumor seeds to be controlled, leading to many more eyes being saved. However, melphalan hydrochloride (MH) degrades rapidly in solution, increasing logistical complexity with respect to time between medication preparation and administration for intravitreal administration under anesthesia for retinoblastoma. A new propylene glycol-free melphalan (PGFM) formulation has greater stability and could therefore improve access and adoption of intravitreal chemotherapy, allowing more children to retain their eye(s). We compared the efficacy and toxicity of both formulations, using our rabbit xenograft model and clinical patient experience. Three weekly 12.5 µg intravitreal injections of MH or PGFM (right eye), and saline (left eye), were administered to immunosuppressed rabbits harboring human WERI-Rb1 vitreous seed xenografts. Residual live cells were quantified directly, and viability determined by TUNEL staining. Vitreous seeds were reduced 91% by PGFM (p = 0.009), and 88% by MH (p = 0.004; PGFM vs. MH: p = 0.68). All residual cells were TUNEL-positive (non-viable). In separate experiments to assess toxicity, three weekly 12.5 µg injections of MH, PGFM, or saline were administered to non-tumor-bearing rabbits. Serial electroretinography, optical coherence tomography (OCT) and OCT-angiography were performed. PGFM and MH both caused equivalent reductions in electroretinography amplitudes, and loss of retinal microvasculature on OCT-angiography. The pattern of retinal degeneration observed on histopathology suggested that segmental retinal toxicity associated with all melphalan formulations was due to a vitreous concentration gradient-effect. Efficacy and toxicity were assessed for PGFM given immediately (within 1 h of reconstitution) vs. 4 h after reconstitution. Immediate- and delayed-administration of PGFM showed equivalent efficacy and toxicity. In addition, we evaluated efficacy and toxicity in patients (205 eyes) with retinoblastoma vitreous seeds, who were treated with a total of 833 intravitreal injections of either MH or PGFM as standard of care. Of these, we analyzed 118 MH and 131 PGFM monotherapy injections in whom serial ERG measurements were available to model retinal toxicity. Both MH and PGFM caused reductions in electroretinography amplitudes, but with no statistical difference between formulations. Comparing those patient eyes treated exclusively with PGFM versus those treated exclusively with MH, efficacy for tumor control and globe salvage was equivalent (PGFM vs. MH: 96.2% vs. 93.8%, p = 0.56), but PGFM-treated eyes received fewer injections than MH-treated eyes (average 3.2 ± 1.9 vs. 6.4 ± 2.1 injections, p < 0.0001). Taken together, these rabbit experiments and our clinical experience in retinoblastoma patients demonstrate that MH and PGFM have equivalent efficacy and toxicity. PGFM was more stable, with no decreased efficacy or increased toxicity even 4 h after reconstitution. We therefore now use PGFM over traditional MH for our patients for intravitreal treatment of retinoblastoma.

Melphalan induces cardiotoxicity through oxidative stress in cardiomyocytes derived from human induced pluripotent stem cells.

BACKGROUND: Treatment-induced cardiotoxicity is a leading noncancer-related cause of acute and late onset morbidity and mortality in cancer patients on antineoplastic drugs such as melphalan-increasing clinical case reports have documented that it could induce cardiotoxicity including severe arrhythmias and heart failure. As the mechanism by which melphalan impairs cardiac cells remains poorly understood, here, we aimed to use cardiomyocytes derived from human induced pluripotent stem cells (hiPSC-CMs) to investigate the cellular and molecular mechanisms of melphalan-induced cardiotoxicity. METHODS: hiPSC-CMs were generated and treated with clinically relevant doses of melphalan. To characterize melphalan-induced cardiotoxicity, cell viability and apoptosis were quantified at various treatment durations. Ca2+ transient and contractility analyses were used to examine the alterations of hiPSC-CM function. Proteomic analysis, reactive oxygen species detection, and RNA-Sequencing were conducted to investigate underlying mechanisms. RESULTS: Melphalan treatment of hiPSC-CMs induced oxidative stress, caused Ca2+ handling defects and dysfunctional contractility, altered global transcriptomic and proteomic profiles, and resulted in apoptosis and cell death. The antioxidant N-acetyl-L-cysteine attenuated these genomic, cellular, and functional alterations. In addition, several other signaling pathways including the p53 and transforming growth factor-ß signaling pathways were also implicated in melphalan-induced cardiotoxicity according to the proteomic and transcriptomic analyses. CONCLUSIONS: Melphalan induces cardiotoxicity through the oxidative stress pathway. This study provides a unique resource of the global transcriptomic and proteomic datasets for melphalan-induced cardiotoxicity and can potentially open up new clinical mechanism-based targets to prevent and treat melphalan-induced cardiotoxicity.

Pig-a gene mutation assay study design: critical assessment of 3- versus 28-day repeat-dose treatment schedules.

The in vivo Pig-a assay is being used in safety studies to evaluate the potential of chemicals to induce somatic cell gene mutations. Ongoing work is aimed at developing an Organisation for Economic Cooperation and Development (OECD) test guideline to support routine use for regulatory purposes (OECD project number 4.93). Among the details that will need to be articulated in an eventual guideline are recommended treatment and harvest schedules. With this in mind, experiments reported herein were performed with Wistar Han rats exposed to aristolochic acid I (AA), 1,3-propane sultone, chlorambucil, thiotepa or melphalan using each of two commonly used treatment schedules: 3 or 28 consecutive days. In the case of the 3-day studies, blood was collected for Pig-a analysis on days 15 or 16 and 29 or 30. For the 28-day studies blood was collected on day 29 or 30. The effect of treatment on mutant reticulocytes and mutant erythrocytes was evaluated with parametric pair-wise tests. While each of the five mutagens increased mutant phenotype cell frequencies irrespective of study design, statistical significance was consistently achieved at lower dose levels when the 28-day format was used (e.g. 2.75 vs 20 mg/kg/bw for AA). To more thoroughly investigate the dose-response relationships, benchmark dose (BMD) analyses were performed with PROAST software. These results corroborate the pair-wise testing results in that lower BMD values were obtained with the 28-day design. Finally, mutagenic potency, as measured by BMD analyses, most consistently correlated with the mutagens' tumorigenic dose 50 values when the lengthier treatment schedule was used. Collectively, these results suggest that both 3- and 28-day treatment schedules have merit in hazard identification-type studies. That being said, for the purpose of regulatory safety assessments, there are clear advantages to study designs that utilise protracted exposures.

Low retinal toxicity of intravitreal carboplatin associated with good retinal tumour control in transgenic murine retinoblastoma.

BACKGROUND: Retinoblastoma is a rare intraocular malignancy in children. Current treatments have many adverse effects. New therapeutic approaches like intravitreal injections of chemotherapies are currently being developed but their toxicities need to be evaluated on animal models. This study compares the efficacy and toxicity of intravitreal melphalan, topotecan and carboplatin, alone or in combination (sequential administration), in the LHBetaTag retinoblastoma mice. METHODS: Mice were divided into nine groups: control, carboplatin 1.5 and 4 µg, melphalan 0.1 and 1 µg, topotecan 0.1 and 1 µg, carboplatin 4 µg/topotecan 0.1 µg and melphalan 1 µg/topotecan 0.1 µg. The follow-up was performed using fundus imaging and optical coherence tomography combined with histopathological analysis. Absence of tumour and presence of calcified tumours were the criteria for therapeutic response assessment. Ocular complications were assessed after four weekly injections. Retinal toxicity was defined by the decrease of retinal thickness and of the number of retinal layers. RESULTS: Topotecan was inactive on retinal tumours. Melphalan (1 µg) led to a complete tumour control in 91.7% of eyes. Carboplatin strongly decreased the tumour burden (85.7-93.8% of eyes without retinal tumour). The intravitreal injection itself led to ocular complications (25% of media opacities and 45.7% of retinal detachment). Only melphalan at 1 µg showed a strong retinal toxicity. The two combinations showed a good efficacy in reducing the number of eyes with retinal tumours with a reduced retinal toxicity. CONCLUSIONS: This preclinical study suggests that intravitreal injection of carboplatin has a low toxicity and could be evaluated in clinical practice to treat patients suffering from retinoblastoma.

Effect of Primary and Secondary Beads of Carbon Enterosorbent on Haematological Parameters and Oxidative Stress Development Caused by Melphalan in Rats.

Background and Objectives: Side effects of anti-cancer drugs are usually accompanied by oxidative stress, including myelotoxicity. We evaluated the potential of oral highly activated micro-/macroporous carbon adsorbents (bulk density of 0.16 g/cm3, surface area calculation by Brunauer-Emmett-Teller model (SBET) > 2200 m2/g, derived from proprietary phenolic resin beads) to alleviate oxidative stress and myelotoxicity in rats. Materials and Methods: A single injection of cytostatic melphalan (L-PAM) at a dose of 4 mg/kg was used for modelling. Two forms of activated carbon were used: AC1-primary beads with the particle size range of 125-250 µm, and AC2-micronized AC1 with a mean particle size of ~1 µm. We measured haematological parameters white blood cells, red blood cells, platelet count, and haemoglobin level. Oxidative stress intensity was evaluated using the following markers: total levels of reactive oxygen species (ROS) in blood plasma; catalase activity (CAT) and pro-oxidant/antioxidant ratio in blood haemolysate samples; level of reduced glutathione (GSH) in liver tissues; oxidative modification of proteins, OPM (APHD, aldehyde-dinitrophenylhydrazone derivatives and KPHD, ketone dinitrophenylhydrazone derivatives) and malonic dialdehyde (MDA) in blood plasma and liver samples. Results: AC2 administration promoted significant myeloprotective effect: 1.5-fold increase in leukocytes, 2-fold in neutrophils, 1.5-fold in lymphocytes, and 1.23-fold in platelet count compared to the experimental Melphalan Group. At the same time, AC1 administration resulted in a slight increase in haematological parameters. Both ACs positively corrected important, but diverse, components of oxidative stress. They significantly reduced oxidative modification of blood and liver proteins (especially the AC1 form), normalized the level of reduced glutathione, pro-oxidant/antioxidant ratio and other markers. For some markers, such as ROS production in blood plasma, the use of enterosorbents resulted in non-significant a shift towards normal parameters. Conclusions: Oral activated carbon adsorbents reduce oxidative stress intensity and myelotoxicity; they can be promising means to combat the adverse effects of chemotherapy in clinical practice.

Rabbit Model of Intra-Arterial Chemotherapy Toxicity Demonstrates Retinopathy and Vasculopathy Related to Drug and Dose, Not Procedure or Approach.

Purpose: To use our intra-arterial chemotherapy (IAC) rabbit model to assess the impact of IAC procedure, drug, dose, and choice of technique on ocular structure and function, to study the nature and etiology of IAC toxicity, and to compare to observations in patients. Methods: Rabbits received IAC melphalan (0.4-0.8 mg/kg), carboplatin (25-50 mg), or saline, either by direct ophthalmic artery cannulation, or with a technique emulating nonocclusion. Ocular structure/function were assessed with examination, electroretinography (ERG), fundus photography, fluorescein angiography, optical coherence tomography (OCT), and OCT angiography, prior to and 5 to 6 weeks after IAC. Blood counts were obtained weekly. We reviewed our last 50 IAC treatments in patients for evidence of ocular or systemic complications. Results: No toxicity was seen in the saline control group. With standard (0.4 mg/kg) melphalan, no vascular/microvascular abnormalities were seen with either technique. However, severe microvascular pruning and arteriolar occlusions were seen occasionally at 0.8 mg/kg doses. ERG reductions were dose-dependent. Histology showed melphalan dose-dependent degeneration in all retinal layers, restricted geographically to areas of greatest vascular density. Carboplatin caused massive edema of ocular/periocular structures. IAC patients experienced occasional periocular swelling/rash, and only rarely experienced retinopathy or vascular events/hemorrhage in eyes treated multiple times with triple (melphalan/carboplatin/topotecan) therapy. Transient neutropenia occurred after 46% of IAC procedures, generally after triple therapy. Conclusions: IAC toxicity appears to be related to the specific drug being used and is dose-dependent, rather than related to the IAC procedure itself or the specific technique selected. These rabbit findings are corroborated by our clinical findings in patients.

Phase 2 Study of an Intravenous Busulfan and Melphalan Conditioning Regimen for Autologous Stem Cell Transplantation in Patients with Multiple Myeloma (KMM150).

This prospective study evaluated the efficacy and toxicity of intravenous busulfan and melphalan as a conditioning regimen for autologous stem cell transplantation (ASCT) in patients with multiple myeloma (MM). A total of 99 patients with MM, enrolled between January 2013 and March 2016, received intravenous busulfan (9.6 mg/kg) and melphalan (140 mg/m2) before ASCT. The median time to transplant was 6.2 months, and 90 (90.9%) patients underwent ASCT within 12 months of the diagnosis. The overall response rate after ASCT was 94.0%, including 43.5% with a stringent complete response/complete response, 27.3% with very good partial response, and 23.2% with partial response. The most common severe nonhematologic toxicity (grade 3 to 4) was infection (26.3%) and stomatitis (15.2%). Three (3.2%) patients developed veno-occlusive disease. No treatment-related mortality was observed. After a median follow-up of 26.1 months, the median progression-free survival was 27.2 months (range, 13.0 to 41.4 months) and median overall survival was not reached. In conclusion, a conditioning regimen of intravenous busulfan and melphalan was effective and tolerable. ClinicalTrials.gov. number: NCT01923935.

Pharmacokinetics, Tissue Localization, Toxicity, and Treatment Efficacy in the First Small Animal (Rabbit) Model of Intra-Arterial Chemotherapy for Retinoblastoma.

Purpose: Current intra-arterial chemotherapy (IAC) drug regimens for retinoblastoma have ocular and vascular toxicities. No small-animal model of IAC exists to test drug efficacy and toxicity in vivo for IAC drug discovery. The purpose of this study was to develop a small-animal model of IAC and to analyze the ocular tissue penetration, distribution, pharmacokinetics, and treatment efficacy. Methods: Following selective ophthalmic artery (OA) catheterization, melphalan (0.4 to 1.2 mg/kg) was injected. For pharmacokinetic studies, rabbits were euthanized at 0.5, 1, 2, 4, or 6 hours following intra-OA infusion. Drug levels were determined in vitreous, retina, and blood by liquid chromatography tandem mass spectrometry. To assess toxicity, angiograms, photography, fluorescein angiography, and histopathology were performed. For in situ tissue drug distribution, matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS) was performed. The tumor model was created by combined subretinal/intravitreal injection of human WERI-Rb1 retinoblastoma cells; the tumor was treated in vivo with intra-arterial melphalan or saline; and induction of tumor death was measured by cleaved caspase-3 activity. Results: OA was selectively catheterized for 79 of 79 (100%) eyes in 47 of 47 (100%) rabbits, and melphalan was delivered successfully in 31 of 31 (100%) eyes, without evidence of vascular occlusion or retinal damage. For treated eyes, maximum concentration (Cmax) in the retina was 4.95 µM and area under the curve (AUC0→∞) was 5.26 µM·h. Treated eye vitreous Cmax was 2.24 µM and AUC0→∞ was 4.19 µM·h. Vitreous Cmax for the treated eye was >100-fold higher than for the untreated eye (P = 0.01), and AUC0→∞ was ∼50-fold higher (P = 0.01). Histology-directed MALDI-IMS revealed highest drug localization within the retina. Peripheral blood Cmax was 1.04 µM and AUC0→∞ was 2.07 µM·h. Combined subretinal/intravitreal injection of human retinoblastoma cells led to intra-retinal tumors and subretinal/vitreous seeds, which could be effectively killed in vivo with intra-arterial melphalan. Conclusions: This first small-animal model of IAC has excellent vitreous and retinal tissue drug penetration, achieving levels sufficient to kill human retinoblastoma cells, facilitating future IAC drug discovery.

Visualization and Quantification of Topoisomerase-DNA Covalent Complexes Using the Trapped in Agarose Immunostaining (TARDIS) Assay.

The TARDIS assay was originally developed as a means of detecting and quantifying melphalan and cisplatin DNA adducts at the single cell level, but it has since been adapted to quantify topoisomerase DNA complexes that result from the actions of topoisomerase poisons and this is currently the main use of the assay. The method employs sensitive immunofluorescent detection to quantify topoisomerase molecules covalently coupled to DNA in what are often referred to as cleavage complexes. Free topoisomerase molecules, and other cellular constituents are first removed using salt-detergent extraction of agarose-embedded, unfixed cells. Using these stringent extraction conditions, genomic DNA remains in place in the agarose as "nuclear ghosts," and any covalent attached molecules can be detected and quantified by immunofluorescence with a low background.

Efficacy and Toxicity of Intravitreous Chemotherapy for Retinoblastoma: Four-Year Experience.

PURPOSE: To investigate the efficacy and toxicity of intravitreous melphalan for treatment of retinoblastoma, as a single agent or with concomitant topotecan. PARTICIPANTS: A total of 130 eyes of 120 patients with retinoblastoma receiving 630 intravitreous (melphalan, topotecan) or topotecan periocular injections. A total of 83 (64%) of these eyes were treated with concomitant ophthalmic artery chemosurgery (OAC). DESIGN: Retrospective cohort study. METHODS: Indirect ophthalmoscopy and clinical imaging were used to evaluate clinical response. Ocular survival and disease-free survival were estimated using Kaplan-Meier methods in 130 eyes. Ocular toxicity was evaluated by clinical findings and electroretinography (ERG) on 244 evaluable injections in 63 patients using 30-Hz flicker responses. Analysis was performed using linear mixed effects models with a random intercept and slope for each patient and a fixed effect for number of injections, in addition to any other fixed effect of interest. MAIN OUTCOME MEASURES: Ocular survival, disease-free survival, ERG: peak-to-peak ERG amplitudes in response to 30-Hz photopic flicker stimulation. RESULTS: There were no disease- or treatment-related deaths, and no patient developed externalization of tumor or metastatic disease. Two-year Kaplan-Meier estimates of ocular survival and disease-free survival were 94.2% (95% confidence interval, 89.2-99.4) and 86.2% (95% confidence interval, 78.7-94.5), respectively. There was a significant association between the number of injections and diminished ERG responses, such that on average each intravitreous melphalan injection was associated with a 5.3-µV decrease in ERG amplitude (P < 0.001). Concomitant intra-arterial chemotherapy (P = 0.01) and greater inherent ocular pigment also were significantly associated with a reduction in ERG (P = 0.045). Patient age and weight, new injection site location, addition of topotecan, concomitant focal treatment, and time interval between injections were not significantly associated with toxicity. CONCLUSIONS: Intravitreous melphalan is an effective treatment for vitreous seeding in retinoblastoma, resulting in high rates of ocular survival and disease-free survival. However, in this study, each injection of melphalan was associated, on average, with a decrement in ERG response. The findings suggest increased toxicity (1) when OAC is given within 1 week of the intravitreous injection and (2) in more deeply pigmented eyes.

Evaluation of the RBC Pig-a and PIGRET assays using single doses of hydroxyurea and melphalan in rats.

To evaluate the suitability of the rat Pig-a assay on reticulocytes (PIGRET assay) as a short-term test, red blood cell (RBC) Pig-a and PIGRET assays after single doses with hydroxyurea (HU) and melphalan (L-PAM) were conducted and the results of both assays were compared. HU was administered once orally to male SD rats at 250, 500 and 1000mg/kg, and both assays were conducted using peripheral blood withdrawn from the jugular vein at 1, 2 and 4 weeks after dosing. L-PAM was administered at 1.25, 2.5 and 5mg/kg in the same manner. L-PAM produced significant dose-dependent increases in mutant frequencies in the PIGRET assay after single oral doses, but did not produce dose-dependent increases in mutant frequencies in the RBC Pig-a assay. These results suggest that the PIGRET assay is more sensitive for the evaluation of the mutagenic potential of L-PAM than the RBC Pig-a assay. In contrast, HU, a clastogenic but not DNA-reactive compound, gave negative results in both assays. The results with these 2 chemicals indicate that the single-dose PIGRET assay in rats has the potential to properly detect DNA-reactive compounds that directly cause DNA damage in a short-term assay.

Enterosorption combined with granulocyte colony stimulating factor decreases melphalan gonadal toxicity.

UNLABELLED: Today due to improvements in cancer treatment there is an increasing number of long-term cancer survivors, many of whom suffer from infertility caused by malignancy itself and chemo- or radiotherapy. Also, anticancer therapy may cause myelosuppression. Presently granulocyte colony stimulating factor (G-CSF) is used for prevention and treatment of myelosuppression. Another treatment option used to decrease intoxication and ameliorate side effects of cancer therapy is sorption technology. The aim of our investigation was to study the efficiency of combined use of enterosorption and G-CSF to decrease gonadal toxicity of chemotherapy. MATERIALS AND METHODS: Melphalan (L-PAM) injected i.v. at a single dose of 4 mg/kg to white inbred rats was used as gonadotoxic and myelosuppressing agent. Carbon enterosorbent C2 was administered by intragastric route as a suspension in saline at a dose of 5 ml per 1 kg of rats' body weight (or 900 mg/kg of the dry mass of enterosorbent) daily for 3 days before and for 7 days after L-PAM injection. G-CSF was injected once a day for 4 days starting from the next day after L-PAM administration at a dose of 50 µg/kg. Histological preparations of testicular tissues were examined by light microscopy. RESULTS: Our findings have shown that melphalan caused marked damage of testicular tissues and seminiferous, especially spermatogenic epithelium. The most expressed protection of the histological structure of testes was observed when enterosorbent and G-CSF were used in combination. CONCLUSION: Gonadal toxicity of chemotherapy could be efficiently decreased by the combined use of enterosorption and G-CSF.

Phase II Study of Propylene Glycol-Free Melphalan Combined with Carmustine, Etoposide, and Cytarabine for Myeloablative Conditioning in Lymphoma Patients Undergoing Autologous Stem Cell Transplantation.

The lyophilized formulation of melphalan has several limitations based on its marginal solubility, limited stability after reconstitution, and the requirement to reconstitute it in propylene glycol (PG). PG-free melphalan (Evomela; Spectrum Pharmaceuticals, Irvine CA) overcomes these limitations by using the solubilizing agent Captisol (Ligand Pharmaceuticals, Inc., LaJolla CA) to improve the stability of the reconstituted melphalan and avoid the potential toxicities of PG. This phase II study investigated the safety and efficacy of high-dose PG-free melphalan when included in the carmustine, etoposide, and cytarabine (BEAM) regimen for adult patients with non-Hodgkin lymphoma (NHL) or Hodgkin lymphoma (HL). Carmustine, etoposide, and cytarabine were given at standard doses on day -6 through day -3. PG-free melphalan, 140 mg/m2, was infused over 30 minutes on day -2. The primary endpoint was toxicity. Fifty patients (33 NHL/17 HL) completed BEAM with PG-free melphalan and stem cell infusion. The most common grades 3 to 4 nonhematologic toxicities were neutropenic fever (68%), infections (36%), and electrolyte abnormalities. Forty-one patients (82%) had oral mucositis, which was mostly grades 1 to 2 (6% grade 3). Moderate or severe gastrointestinal toxicities were uncommon. There were no treatment-related deaths. Forty-nine patients (98%) had neutrophil and platelet engraftment at a median of 10 and 19 days, respectively. At response assessment at 60 to 100 days after autologous stem cell transplantation, 42 patients (82%) were in complete remission, 2 in partial remission, and 6 had progressive disease. Progression-free survival at 1 year was 70%. These results demonstrate that PG-free melphalan can be used in place of the standard, lyophilized formulation of melphalan in the BEAM regimen for lymphoma patients undergoing autologous stem cell transplantation. It has a safety profile that compares favorably with standard lyophilized melphalan, and the engraftment rate and response rates were consistent with expectations.

Melphalan 200 mg/m2 in patients with renal impairment is associated with increased short-term toxicity but improved response and longer treatment-free survival.

Data on the effectiveness and toxicity of high-dose melphalan in patients with renal impairment (RI) are lacking. We evaluated the impact of RI on outcomes of patients with multiple myeloma treated with melphalan 200 mg/m2 (Mel200) and autologous stem cell transplantation. Similar baseline characteristics were seen among 46 patients with creatinine clearance (CrCl) <60 mL/min (median 50 mL/min, range 20-59) and 103 patients with CrCl ⩾60 mL/min (median 83 mL/min, range 60-128). Patients with CrCl <60 mL/min had longer time to neutrophil (P=0.008) and platelet engraftment (P<0.001). Diarrhea, duration of total parenteral nutrition use and infection were significantly higher in the CrCl <60 mL/min group. With a median follow-up of 35 months (range 2-132) in the CrCl <60 mL/min group and 47 months (range 1-45) in the CrCl ⩾60 mL/min group, overall survival was comparable between the two groups. Median treatment-free survival was longer in the RI group (37 vs 17 months, P=0.0025). Multivariate analysis showed CrCl <60 mL/min (hazard ratio (HR) 3.5), and prior proteasome inhibitor therapy (HR 2.441) both predicted longer treatment-free survival. We consider Mel200 safe and effective in patients with CrCl between 30 and 60 mL/min.

Effect of severe hypoalbuminemia on toxicity of high-dose melphalan and autologous stem cell transplantation in patients with AL amyloidosis.

High-dose melphalan with stem cell transplantation (HDM/SCT) extends survival and induces hematologic and clinical responses in patients with light chain (AL) amyloidosis. Eighty percent of melphalan is bound to plasma proteins (60% albumin-bound). We hypothesized that patients with profound hypoalbuminemia have a greater free melphalan fraction and more toxicity. Patients with AL amyloidosis treated with HDM/SCT between 2011 and 2014 with severe hypoalbuminemia (SH), defined as serum albumin ⩽2 g/dL were studied retrospectively. Sixteen patients with SH were identified. Forty-one patients without severe hypoalbuminemia (WSH) treated between 2011 and 2012 served as control. The incidence of acute renal failure requiring hemodialysis was 25% among patients with SH, compared with 5% among patients WSH (P=0.05). Not all patients who needed dialysis required it long term; 6.25% for SH and 2.44% for WSH (P=0.49). The rates of grade 3 or 4 febrile neutropenia and gastrointestinal toxicities were not significantly different between the groups. Engraftment kinetics were similar for both groups. Grade 4 renal toxicity and grade 3 lightheadedness were more frequent in patients with SH undergoing HDM/SCT for AL amyloidosis. Further studies into the mechanism of increased renal toxicity in patients with SH are warranted.

Busulfan-melphalan in high-risk neuroblastoma: the 30-year experience of a single institution.

High-dose chemotherapy (HDC) was investigated in high-risk neuroblastoma (HR-NBL) to reduce the risk of relapse. We report the results of the 30-year experience of a cohort of patients with HR-NBL treated with high-dose (HD) busulfan (Bu)-containing regimens. From 1980 to 2009, 215 patients aged >1 year with stage 4 NBL were treated with HD Bu-containing regimens at Gustave Roussy. These data were prospectively recorded in the Pediatric Transplantation Database. The median age at diagnosis was 40 months (12-218 months). All patients had a stage 4 neuroblastoma. NMYC amplification was displayed in 24% of the tumors. The hematopoietic support consisted of bone marrow or PBSCs in 46% and 49% of patients, respectively. The 5-year event-free survival and overall survival rates of the whole cohort were 35.1% and 40%, respectively. Age at diagnosis, bone marrow involvement and tumor response after induction chemotherapy were significant prognostic factors. Toxicity was manageable and decreased over time, owing to both PBSC administration and better supportive care. Based on this experience, HD Bu-melphalan (Mel) has been implemented in Europe and compared with Carboplatin-Etoposide-Mel in the European SIOP Neuroblastoma (SIOPEN)/HR-NBL randomized protocol. It has now become the standard HDC in the SIOPEN HR strategy.