Associations of High-Dose Melphalan Pharmacokinetics and Outcomes in the Setting of a Randomized Cryotherapy Trial

Optimizing high dose melphalan

Melphalan, has been a major component of myeloma therapy since the 1950s. In the context of hematopoietic cell transplantation (HCT), high dose melphalan (HDM) is the most common conditioning regimen used due to its potent anti-myeloma effects and manageable toxicities. Common toxicities associated with HDM include myelosuppression, gastrointestinal issues, and mucositis. Established approaches to reduce these toxicities encompass dose modification, nausea prophylaxis with 5HT3 receptor antagonists, cryotherapy, amifostine use, and growth factors. Optimization of melphalan exposure through personalized dosing and its combination with other agents like busulfan, or bendamustine show promise. Propylene glycol-free melphalan (Evomela) represents a novel formulation aiming to enhance drug stability and reduce adverse effects. This review explores strategies to enhance the efficacy and mitigate the toxicity of HDM in multiple myeloma. Future directions involve exploring these strategies in clinical trials to improve the safety and efficacy of HDM, thereby enhancing outcomes for multiple myeloma patients undergoing autologous HCT.

Cryotherapy for oral mucositis in cancer: review of systematic reviews and meta-analysis

BACKGROUND

One of the most common side effects of cancer treatment is oral mucositis. Although studies have shown that oral cryotherapy has a favourable effect on oral mucositis, the reliability of the results is questionable.

OBJECTIVE

The goal of this umbrella review was to provide insight into the effects of oral cryotherapy against oral mucositis in patients with cancer, as well as to assess the certainty of this evidence.

METHOD

Studies were searched for through PubMed, Scopus and Web of Science, with no restrictions until August 2021. The risk ratio (RR) and 95% CI for each meta-analysis were recalculated using a random-effects model, and the certainty of the evidence was judged using Grading of Recommendations Assessment, Development and Evaluation.

RESULTS

Ten meta-analyses including 25 original RCTs that fit our inclusion criteria were included. The use of oral cryotherapy markedly reduced the occurrence of overall (RR 0.72, 95% CI 0.64 to 0.83, n=20 trials), moderate to severe (RR 0.60, 95% CI 0.45 to 0.80, n=16 trials) and severe oral mucositis (RR 0.48, 95% CI 0.34 to 0.67, n=16 trials), as well as average severity score of oral mucositis (standardised mean difference=-0.94, 95% CI -1.28 to -0.59, n=4 trials) in comparison to a control group; however, the certainty of evidence for all outcomes was rated very low.

CONCLUSION

In patients with cancer, oral cryotherapy appears to greatly lower the severity and occurrence of oral mucositis, but, with very low certainty of evidence.

Cryopreventive temperatures prior to chemotherapy

The superiority of oral cryotherapy (OC) for prevention of chemotherapy-induced oral mucositis (OM) has been demonstrated in several trials. In clinical settings, cooling is usually initiated prior to the chemotherapy infusion. It then continues during the infusion, and for a period after the infusion has been completed. While the cooling period post-infusion depends on the half-life of the chemotherapeutic drug, there is no consensus on when cooling should be initiated prior to the infusion. The lowest achieved temperature in the oral mucosa is believed to provide the best condition for OM prevention. Given this, it was of interest to investigate when along the course of intraoral cooling this temperature is achieved. In total, 20 healthy volunteers participated in this randomized crossover trial. Each subject attended three separate cooling sessions of 30 min each, with ice chips (IC) and the intraoral cooling device (ICD) set to 8 and 15 °C, respectively. At baseline and following 5, 10, 15, 20 and 30 min of cooling, intraoral temperatures were registered using a thermographic camera. The greatest drop in intraoral temperature was seen after 5 min of cooling with IC, ICD^8°C and ICD^15°C, respectively. A statistically significant difference, corresponding to 1.4 °C, was seen between IC and the ICD^15°C (p < 0.05). The intraoral temperature further declined throughout the 30 min of cooling, showing an additional temperature reduction of 3.1, 2.2, and 1.7 °C for IC, ICD^8°C and ICD^15°C, respectively.

Evaluating the Impacts of CYP3A4*1B and CYP3A5*3 Variations on Pharmacokinetic Behavior and Clinical Outcomes in Multiple Myeloma Patients With Autologous Stem Cell Transplant

BACKGROUND/AIM

There exists considerably large interpatient variability in pharmacokinetic exposure of high dose melphalan in multiple myeloma patients with hematopoietic stem-cell transplantation. In this study, we aimed to evaluate the potential impacts of CYP3A4*1B (rs2940574) and CYP3A5*3 (rs776746) variations on pharmacokinetic properties of melphalan and clinical outcomes in multiple myeloma (MM) patients.

PATIENTS AND METHODS

Genotypes of CYP3A4*1B (rs2940574) and CYP3A5*3 (rs776746) were determined by validated gene-specific real-time PCR (RT-PCR) assays using DNA samples from 108 MM patients; plasma concentrations of melphalan at different time points were quantified using liquid chromatography-tandem mass spectrometry (LC-MS/MS).

RESULTS

CYP3A4*1B/*1B and CYP3A5*3/*3 carriers appeared to have a short median progression-free survival time and a higher maximum melphalan plasma concentration than non-carriers [792 vs. over 950 days, p=0.08; 9.91 (2.67, 34.03) vs. 8.66 (4.46, 17.61) mg/l, p=0.039].

CONCLUSION

CYP3A4*1B/*1B and CYP3A5*3/*3 variations might influence melphalan therapy in MM patients through yet-to-be-identified mechanisms.

The effect of cryotherapy on oral mucositis management in patients undergoing stem cell transplantation: A systematic review of randomized controlled trials

AIM

This study aimed to investigate the effect of cryotherapy on oral mucositis management in patients undergoing stem cell transplantation.

BACKGROUND

Oral mucositis is among the most common symptoms of stem cell transplantation. Cryotherapy may be an important treatment option in the oral mucositis process.

DESIGN

A systematic review.

DATA SOURCES

A literature review of studies published in the English language was conducted on Web of Science, Springer Link, Science Direct, Cochrane Library, PubMed, Scopus, ProQuest, Ovid, EBSCOhost/CINAHL Complete and MEDLINE databases until April 2022. The studies reviewed covered the years between 2006 and 2020. The data were summarized narratively.

REVIEW METHODS

This systematic review was organized in accordance with the Cochrane 2022 guidelines and reported using Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

RESULTS

Nine studies were included in the systematic review. No significant publication bias was found in the main results. The results showed that the cryotherapy intervention had a positive effect on oral mucositis in patients undergoing stem cell transplantation.

CONCLUSIONS

In this systematic review of nine randomized controlled trials, the majority of the studies show that cryotherapy intervention can be an effective method for reducing oral mucositis in patients undergoing stem cell transplantation.

The Nitrogen Mustards

The nitrogen mustards are powerful cytotoxic and lymphoablative agents and have been used for more than 60 years. They are employed in the treatment of cancers, sarcomas, and hematologic malignancies. Cyclophosphamide, the most versatile of the nitrogen mustards, also has a place in stem cell transplantation and the therapy of autoimmune diseases. Adverse effects caused by the nitrogen mustards on the central nervous system, kidney, heart, bladder, and gonads remain important issues. Advances in analytical techniques have facilitated the investigation of the pharmacokinetics of the nitrogen mustards, especially the oxazaphosphorines, which are prodrugs requiring metabolic activation. Enzymes involved in the metabolism of cyclophosphamide and ifosfamide are very polymorphic, but a greater understanding of the pharmacogenomic influences on their activity has not yet translated into a personalized medicine approach. In addition to damaging DNA, the nitrogen mustards can act through other mechanisms, such as antiangiogenesis and immunomodulation. The immunomodulatory properties of cyclophosphamide are an area of current exploration. In particular, cyclophosphamide decreases the number and activity of regulatory T cells, and the interaction between cyclophosphamide and the intestinal microbiome is now recognized as an important factor. New derivatives of the nitrogen mustards continue to be assessed. Oxazaphosphorine analogs have been synthesized in attempts to both improve efficacy and reduce toxicity, with varying degrees of success. Combinations of the nitrogen mustards with monoclonal antibodies and small-molecule targeted agents are being evaluated. SIGNIFICANCE STATEMENT: The nitrogen mustards are important, well-established therapeutic agents that are used to treat a variety of diseases. Their role is continuing to evolve.

Population Pharmacokinetics of Melphalan in a Large Cohort of Autologous and Allogeneic Hematopoietic Cell Transplantation Recipients: Towards Individualized Dosing Regimens

BACKGROUND AND OBJECTIVES

High-dose melphalan is an integral part of conditioning chemotherapy prior to both autologous and allogeneic hematopoietic cell transplantation. While underexposure may lead to relapse, overexposure may lead to toxicities include mucositis, diarrhea, bone marrow suppression, and rarely sinusoidal obstruction syndrome. In this study, we describe the population pharmacokinetics of high-dose melphalan as a first step towards individualized dosing.

METHODS

Melphalan samples were collected in patients receiving an allogeneic or autologous hematopoietic cell transplantation between August 2016 and August 2020 at the Memorial Sloan Kettering Cancer Center. A population-pharmacokinetic model was developed using NONMEM.

RESULTS

Based on a total of 3418 samples from 452 patients receiving a median cumulative dose of 140 mg/m2, a two-compartment population-pharmacokinetic model was developed. Fat-free mass was a covariate for clearance, central volume of distribution, and inter-compartmental clearance, while glomerular filtration rate predicted clearance. Simulation studies showed that based on fixed body surface area-based dosing, renal impairment has a higher impact in increasing melphalan exposure compared with obesity.

CONCLUSIONS

The proposed model adequately describes the population pharmacokinetics of melphalan in adult patients receiving a hematopoietic cell transplantation. This model can be used to define the therapeutic window of melphalan, and subsequently to develop individualized dosing regimens aiming for that therapeutic window in all patients.

Efficacy of Oral Cryotherapy in the Prevention of Oral Mucositis Associated with Cancer Chemotherapy: Systematic Review with Meta-Analysis and Trial Sequential Analysis

BACKGROUND

This review aimed to evaluate the efficacy of oral cryotherapy in the prevention of chemotherapy-induced oral mucositis using meta-analysis and trial sequential analysis, as well as to assess the quality of the results by the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach.

METHODS

A comprehensive search of three databases including Medline, Embase and Central was performed to identify randomized controlled trials that used oral cryotherapy for the prevention of chemotherapy-induced oral mucositis. The primary outcome was the incidence of oral mucositis for trials employing oral cryotherapy as the intervention for the prevention of oral mucositis. The meta-analysis was performed using the random-effects model and random errors of the meta-analyses were detected by trial sequential analysis.

RESULTS

A total of 14 RCTs with 1577 participants were included in the present meta-analysis. Patients treated with oral cryotherapy were associated with a significantly lower risk of developing oral mucositis of any grade (risk ratio (RR), 0.67 (95% CI: 0.56-0.81, p < 0.05)). Findings from the subgroup analyses showed that oral cryotherapy significantly reduced the risk of oral mucositis in patients undergoing bone marrow transplantation (RR 0.69, CI: 0.54-0.89, p < 0.05) as well as chemotherapy (RR 0.66, CI: 0.58-0.75, p < 0.05). Findings from the trial sequential analysis suggested that the evidence on oral cryotherapy as a preventive intervention for oral mucositis in patients with solid malignancies receiving conventional chemotherapy was conclusive.

CONCLUSION

Oral cryotherapy is effective in preventing oral mucositis in patients undergoing chemotherapy for the management of solid malignancies. The use of oral cryotherapy in preventing oral mucositis in bone marrow transplantation settings showed promising efficacy, but the evidence is not conclusive and requires more high-quality randomized controlled trials.

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.

Influence of single nucleotide polymorphism of LAT1 on therapeutic response to gabapentinoids in Pakistani patients with neuropathic pain

Gabapentinoids are substrate of L-type amino acid transporter 1 (LAT1) for distribution across the blood-brain barrier. The present study aimed to evaluate the effect of LAT1 rs4240803 genetic polymorphism on the clinical efficacy and tolerability of gabapentinoids in Pakistani patients with neuropathic pain. Three-hundred and ninety-two patients were recruited, genotyped for SNP rs4240803, and followed up for eight weeks to evaluate the clinical response to gabapentinoids in terms of pain relief, inadequate response, and the emergence of adverse events. LAT1 rs4240803 GG, GA, and AA genotype frequency were 33.42%, 47.96% and 18.62%, respectively. Out of 392 patients, 323 responded to the treatment and 17.6% discontinued either due to insufficient response or intolerable adverse events (AEs). GA genotype was more frequent in non-responder group (P ˂ 0.001). Maximum pain responders (≥50%) in combination with the lowest incidence of AEs were observed in the GG group, whereas partial responders belonged to GA genotype and with the highest frequency of somnolence (83.6%) and dizziness (69.9%). Overall, 72.5% patients with GA genotype experienced AEs (P ˂ 0.001). In conclusion, clinical outcomes of gabapentinoids are influenced by LAT1 rs4240803 polymorphism and population pharmacogenetics should be considered to evaluate the maximum potential of gabapentinoids in the management of neuropathic pain.

Development of a method for clinical pharmacokinetic testing to allow for targeted Melphalan dosing in multiple myeloma patients undergoing autologous transplant

AIMS

High dose melphalan (HDM) and autologous stem cell transplant (ASCT) is standard of care for multiple myeloma (MM), but there is significant variability in melphalan exposure (area under the plasma drug concentration-time curve, AUC) when using body surface area-based dosing. Our aim was to establish a method of pharmacokinetic (PK) testing for real-time melphalan dose adjustments.

METHODS

We performed a prospective PK study of melphalan 140 or 200 mg/m2 in MM patients undergoing ASCT. Twenty MM patients were administered HDM on days -2 and - 1, with PK sampling at 8-10 time points. PK testing was performed on day -2 in all patients, and on day -1 in 5 patients.

RESULTS

Less than 20% interpatient variation in the day -2 and - 1 AUC was observed. The day -2 range in AUC (4.95-11.28 mg h/L) confirmed significant interpatient variability. The hypothetical total dose ranged from 133-302 mg/m2 to achieve the total median AUC. A 4-time point AUC (0, 30, 150 and 240 min) highly correlated with the AUC from the 8-time point schedule. A higher AUC correlated with increased risk of febrile neutropenia (P = .05).

CONCLUSION

Here we outline the methods to establish novel melphalan dosing using PK testing in MM patients undergoing ASCT to target a desired melphalan AUC.

Factors predicting toxicity and response following isolated limb infusion for melanoma: An international multi-centre study

INTRODUCTION

Isolated limb infusion (ILI) is a minimally-invasive procedure for delivering high-dose regional chemotherapy to treat melanoma in-transit metastases confined to a limb. The aim of this international multi-centre study was to identify predictive factors for toxicity and response.

METHODS

Data of 687 patients who underwent a first ILI for melanoma in-transit metastases confined to the limb between 1992 and 2018 were collected at five Australian and four US tertiary referral centres.

RESULTS

After ILI, predictive factors for increased limb toxicity (Wieberdink grade III/IV limb toxicity, n = 192, 27.9%) were: female gender, younger age, procedures performed before 2005, lower limb procedures, higher melphalan dose, longer drug circulation and ischemia times, and increased tissue hypoxia. No patient experienced grade V toxicity (necessitating amputation). A complete response (n = 199, 28.9%) was associated with a lower stage of disease, lower burden of disease (BOD) and thinner Breslow thickness of the primary melanoma. Additionally, an overall response (combined complete and partial response, n = 441, 64.1%) was associated with female gender, Australian centres, procedures performed before 2005, lower limb procedures and lower actinomycin-D doses. On multivariate analysis, higher melphalan dose remained a predictive factor for toxicity, while lower stage of disease and lower BOD remained predictive factors for overall response.

CONCLUSION

ILI is safe and effective to treat melanoma in-transit metastases. Predictive factors for toxicity and response identified in this study will allow improved patient selection and optimization of intra-operative parameters to increase response rates, while keeping toxicity low.

Predictors of increased melphalan exposure correlate with overall survival, nonrelapse mortality, and toxicities in patients undergoing reduced-intensity allogeneic stem cell transplantation with fludarabine and melphalan

The reduced-intensity conditioning regimen, fludarabine and melphalan 140 mg/m² (FM140), is widely adopted in practice. Pharmacokinetic studies report 10-fold interpatient variability in melphalan exposure. We identified low hemoglobin (Hb) and/or creatinine clearance (CrCl), determinants of melphalan pharmacokinetic, as strong predictors of outcomes after high-dose melphalan and autologous transplant. We hypothesized that these variables could predict for outcomes after FM140. Overall survival was shorter in patients with a lower Hb (113 vs. 2536 days; p = 0.004), due to an increased rate of nonrelapse mortality (NRM) (p = 0.0005). Overall survival was also worse in patients with lower CrCl (75 vs. 317 days; p = 0.003), with a significantly worse nonrelapse mortality (p = 0.0023). In a multivariate analysis, a higher Hb and CrCl predicted for better overall survival (p = 0.017). In patients with a lower Hb, the median duration of hospitalization (p = 0.02) and the mean duration of diarrhea (p = 0.008) were longer. In patients with a lower CrCl, the median duration of hospitalization (p = 0.06) and the mean duration of diarrhea (p = 0.0009) longer, and the rate of infection was higher (p = 0.02). We show for the first time that Hb and CrCl represent important determinants of outcomes after FM140, suggesting that pharmacokinetic-directed dosing may be beneficial in achieving optimal outcomes.

PARP Inhibition Synergizes with Melphalan but Does not Reverse Resistance Completely

High-dose melphalan (MEL) and autologous stem cell transplantation (ASCT) is the standard of care in the treatment of multiple myeloma (MM). Resistance to MEL has been linked to increased DNA repair. Here we sought to identify whether inhibition of poly(ADP-ribose) polymerase (PARP) synergizes with MEL and can overcome resistance. We tested the synergistic cytotoxicity of 3 inhibitors of PARP (PARPi)-veliparib (VEL), olaparib (OLA), and niraparib (NIRA)-combined with MEL in RPMI8226 and U266 MM cell lines, as well as in their MEL resistance counterparts, RPMI8226-LR5 (LR5) and U266-LR6 (LR6). The addition of VEL, OLA, and NIRA to MEL reduced the half maximal inhibitory concentration (IC₅₀) in RPMI8226 cells from 27.8 µM to 23.1 µM, 22.5 µM, and 18.0 µM, respectively. Similarly, the IC₅₀ of MEL in U266 cells was decreased from 6.2 µM to 3.2 µM, 3.3 µM, and 3.0 µM, respectively. In LR5 and LR6 cells, PARPi did not reverse MEL resistance. We confirmed this in a NOD/SCID/gamma null xenograft mouse model with either MEL-sensitive (RPMI8226) or MEL-resistant (LR5) MM. Treatment with a MEL-VEL combination prolonged survival compared with MEL alone in RPMI8226 mice (107 days versus 67.5 days; P = .0009), but not in LR5 mice (41 versus 39 days; P = .09). We next tested whether 2 double-stranded DNA repair mechanisms, homologous recombination (HR) and nonhomologous end-joining (NHEJ), cause MEL resistance in LR5 and LR6 cells. In an HR assay, LR6 cells had a 4.5-fold greater HR capability than parent U226 cells (P = .05); however, LR5 cells had an equivalent HR ability as parent RPMI8226 cells. We hypothesized that NHEJ may be a mediator of MEL resistance in LR5 cells. Given that DNA-PK is integral to NHEJ and may be a therapeutic target, we treated LR5 cells with the DNA-PK inhibitor NU7026 in combination with MEL. Although NU7026 alone at 2.5 µM had no cytotoxicity, in combination it completely reversed resistance to MEL (MEL IC₅₀, 46.4 µM versus 14.4 µM). We examined the clinical implications of our findings in a dataset of 414 patients treated with tandem ASCT. High PARP1 expressers had lower survival compared with patients with low expression (median 42.7 months versus median not reached; P = .003). We hypothesized that combined expression of the HR gene BRCA1, the NHEJ gene PRKDC (DNA-PK), and PARP1 may predict survival and found that overexpression of 0 (n = 101), 1 or 2 (n = 287), or all 3 (n = 26) genes had a negative impact on median survival (undefined versus 57.8 months versus 14.8 months; P < .0001). Here we demonstrate that PARPi synergized with MEL, but that resistance (which may be due to HR and NHEJ pathways) is not completely reversed by PARPi. In addition, we observed that a 3-gene analysis may be tested to identify patients resistant or sensitive to high-dose MEL.

Systematic review of oral cryotherapy for the management of oral mucositis in cancer patients and clinical practice guidelines

PURPOSE

To update the 2013 Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology (MASCC/ISOO) clinical practice guidelines on oral cryotherapy for the management of oral mucositis (OM) caused by cancer therapies.

METHODS

A systematic review was conducted by the Mucositis Study Group of MASCC/ISOO. The evidence for each intervention for specific cancer treatment modalities was assigned a level of evidence (LoE). The findings were added to the database used to develop the 2013 MASCC/ISOO clinical practice guidelines. Based on the LoE, the guidelines were set as: recommendation, suggestion, or no guideline possible.

RESULTS

A total of 114 papers were identified: 44 from PubMed and 70 from Web of Science. After abstract triage and merging with the 2013 database, 36 papers were reviewed. The LoE for prevention of OM with oral cryotherapy in patients undergoing autologous hematopoietic stem cell transplant using high-dose melphalan conditioning protocols was upgraded, and the guideline changed to recommendation. Additionally, the recommendation for prevention of OM with oral cryotherapy in patients receiving bolus 5-fluorouracil for the treatment of solid tumors was confirmed. No guidelines were possible for other clinical settings.

CONCLUSIONS

The evidence supports recommendations for the use of oral cryotherapy for the prevention of OM for either (i) patients undergoing autologous hematopoietic stem cell transplant with high-dose melphalan conditioning protocols or (ii) patients receiving bolus 5-fluorouracil chemotherapy.

Pharmacokinetics and Efficacy of Generic Melphalan Is Comparable to Innovator Formulation in Patients With Multiple Myeloma Undergoing Autologous Stem Cell Transplantation

BACKGROUND

High-dose melphalan (MEL) is the standard conditioning regimen used for autologous stem cell transplantation (ASCT) in patients with multiple myeloma (MM). Generic MEL is routinely used in various transplant centers across the world including ours due to its reduced cost and ease of availability. We compared the pharmacokinetics (PK) and the clinical efficacy of generic MEL with that of the innovator formulation in MM patients undergoing ASCT.

PATIENTS AND METHODS

Sixty-three patients diagnosed with MM receiving high-dose MEL were included in this study. MEL levels in plasma were measured using a liquid chromatography tandem mass spectrometry (HPLC/MS-MS) protocol and non-linear mixed effects modeling was used to evaluate the PK of the data.

RESULTS

The interindividual variability (IIV) in MEL area under the concentration versus time curve (AUC) and clearance (CL) were 4.39, 5.88-fold for generic, and 4.34, 6.85-fold for the innovator formulation, respectively. The median MEL AUC and CL were comparable between the 2 formulations. The population PK analysis showed age and creatinine CL as the only significant covariates explaining IIV in MEL AUC/CL. Analysis of MEL PK parameters with clinical outcome showed no significant differences in terms of onset and severity of mucositis, day to neutrophil and platelet engraftment, as well as response status on day 100 post ASCT between patients receiving generic or innovator formulations of MEL. In addition, neither MEL AUC nor CL was found to be associated with day +100 response.

CONCLUSION

Our study suggests that the PK and efficacy of the generic MEL is comparable to the innovator formulation.

Pretransplant hemoglobin and creatinine clearance correlate with treatment-free survival after autologous stem cell transplantation for multiple myeloma

Melphalan is given at a dose of 200 mg/m² (Mel200) prior to ASCT for multiple myeloma (MM). Pharmacokinetic (PK) studies show a high degree of interpatient variability. We aimed to test the impact of clinical factors previously shown to affect melphalan PK such as hemoglobin (Hgb), fat-free mass (FFM), and creatinine clearance (CrCl) on outcomes. Median Hgb (from day -2 to -1) and FFM were grouped as low or high relative to their sample medians, and CrCl was divided into ≥60 or <60 ml/min. In 133 MM patients, median TFS (defined as time from ASCT to initiation of next subsequent line of therapy or death) was longer in patients with lower Hgb (35 vs. 16 months, p = 0.02). Patients with both lower Hgb and CrCl experienced longer TFS compared to those with higher Hgb and CrCl (35 vs. 13 months, p = 0.03). In multivariate analysis, lower hemoglobin, lower CrCl, and a combined low hemoglobin and CrCl were strongly associated with improved TFS. Patients with a lower hemoglobin or creatinine clearance experienced significantly more toxicity. We show for the first time that Hgb and CrCl are important predictors of outcomes after Mel200. PK-directed melphalan dosing may be beneficial in achieving optimal outcomes.

Treatment of Multiple Myeloma: ASCO and CCO Joint Clinical Practice Guideline

PURPOSE

To provide evidence-based recommendations on the treatment of multiple myeloma to practicing physicians and others.

METHODS

ASCO and Cancer Care Ontario convened an Expert Panel of medical oncology, surgery, radiation oncology, and advocacy experts to conduct a literature search, which included systematic reviews, meta-analyses, randomized controlled trials, and some phase II studies published from 2005 through 2018. Outcomes of interest included survival, progression-free survival, response rate, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.

RESULTS

The literature search identified 124 relevant studies to inform the evidence base for this guideline.

RECOMMENDATIONS

Evidence-based recommendations were developed for patients with multiple myeloma who are transplantation eligible and those who are ineligible and for patients with relapsed or refractory disease.

Cryotherapy as prophylaxis against oral mucositis after high-dose melphalan and autologous stem cell transplantation for myeloma: a randomised, open-label, phase 3, non-inferiority trial

The conditioning therapy used in connection with haematopoietic stem cell transplantation (HSCT) can induce painful oral mucositis, which has negative impacts on patient quality of life and survival, as well as on health-care costs. While cooling of the oral mucosa (cryotherapy) is regarded as standard prophylaxis against oral mucositis, the long duration of the treatment affects compliance owing to side effects. In this prospective, randomised trial, 94 patients (62 males/32 females; median age 59 years, range 34-69) with a diagnosis of myeloma who were undergoing autologous HSCT were randomised 1:1 to receive cryotherapy for 7 h (N = 46) or 2 h (N = 48). Oral mucositis was evaluated prospectively. No significant difference was observed with respect to the proportion of patients who showed grades 3 and 4 toxicity according to the WHO scale (2.1 and 4.3% for 2 and 7 h, respectively; 95% CI -0.09 to 0.049; p = 0.98) as between the groups. Two hours of cryotherapy was as effective as 7 h in terms of protecting against severe oral mucositis in connection with autologous HSCT for myeloma. This trial is registered with ClinicalTrials.gov (NCT03704597).

Pharmacokinetic-Pharmacodynamic Model of Neutropenia in Patients With Myeloma Receiving High-Dose Melphalan for Autologous Stem Cell Transplant

High-dose melphalan (HDM) is part of the conditioning regimen in patients with multiple myeloma (MM) receiving autologous stem cell transplantation (ASCT). However, individual sensitivity to melphalan varies, and many patients experience severe toxicities. Prolonged severe neutropenia is one of the most severe toxicities and contributes to potentially life-threatening infections and failure of ASCT. Granulocyte-colony stimulating factor (G-CSF) is given to stimulate neutrophil proliferation after melphalan administration. The aim of this study was to develop a population pharmacokinetic/pharmacodynamic (PK/PD) model capable of predicting neutrophil kinetics in individual patients with MM undergoing ASCT with high-dose melphalan and G-CSF administration. The extended PK/PD model incorporated several covariates, including G-CSF regimen, stem cell dose, hematocrit, sex, creatinine clearance, p53 fold change, and race. The resulting model explained portions of interindividual variability in melphalan exposure, therapeutic effect, and feedback regulation of G-CSF on neutrophils, thus enabling simulation of various doses and prediction of neutropenia duration.

Pharmacogenetics-based population pharmacokinetic analysis of gabapentin in patients with chronic pain: Effect of OCT2 and OCTN1 gene polymorphisms

Gabapentin (GAB) is eliminated unchanged in urine, and organic cation transporters (OCT2 and OCTN1) have been shown to play a role in GAB renal excretion. This prospective clinical study aimed to evaluate the genetic polymorphisms effect on GAB pharmacokinetic (PK) variability using a population pharmacokinetic approach. Data were collected from 53 patients with chronic pain receiving multiple doses of GAB. Patients were genotyped for SLC22A2 c.808G>T and SLC22A4 c.1507C>T polymorphisms. Both polymorphisms' distribution followed the Hardy-Weinberg equilibrium. An one-compartment model with first-order absorption and linear elimination best described the data. The absorption rate constant, volume of distribution, and clearance estimated were 0.44 h^-1 , 86 L, and 17.3 × (estimated glomerular filtration ratio/89.58)^1.04  L/h, respectively. The genetic polymorphism SLC22A4 c.1507C>T did not have a significant influence on GAB absorption, distribution or elimination. Due to the low minor allelic frequency of SLC22A2 c.808G>T, further studies require higher number of participants to confirm its effect on GAB renal elimination. In conclusion, GAB clinical pharmacokinetics are strongly influenced by renal function and absorption process, but not by the OCTN1 (SLC22A4 c.1507C>T) polymorphism.