A randomized study of melphalan 200 mg/m(2) vs 280 mg/m(2) as a preparative regimen for patients with multiple myeloma undergoing auto-SCT

In the era of Bortezomib-based Induction, intensification of Melphalan-based conditioning with Bortezomib does not improve Survival Outcomes in newly diagnosed Multiple Myeloma: a study from the Chronic Malignancies Working Party of the EBMT

Bortezomib (Vel)- Melphalan 200 mg/m2 (Mel200) (Vel-Mel) has been utilised to intensify conditioning in autologous hematopoietic stem cell transplantation (AHCT) for multiple myeloma (MM). This EBMT registry-based study compared Vel-Mel with Mel200 during upfront AHCT. Between 2010 and 2017, MM patients who received Vel-Mel (n = 292) conditioning were compared with 4,096 Mel200 patients in the same 58 centres. Pre-AHCT, compared to Mel200 patients, Vel-Mel patients had similar International Staging System (ISS) scores and cytogenetic risk profiles; a similar proportion had received bortezomib-based induction (85% and 87.3%, respectively) though they were younger with a better performance status. Vel-Mel patients were more likely to achieve CR post-induction (40.6% vs 20.3%, p < 0.001) and by day 100 of AHCT (CR/VGPR: 70.2 % vs. 57.2%, p < 0.001). There was no difference in 3-year PFS (49% vs 46%, p = 0.06) or early post-AHCT mortality. In multivariable analysis, Vel-Mel associated with inferior PFS (HR: 1.69 (1.27-2.25, p < 0.001) and OS (HR:1.46 (1.14-1.86,p = 0.002), similar to negative effects on PFS of advanced ISS (HR:1.56 (1.33-1.83, p < 0.001), high-risk cytogenetics (HR:1.43(1.18-1.74, p < 0.001) and poor post-induction response(<=PR)(HR: 1.43(1.25-1.62, p < 0.001) Overall, despite superior pre- and post-AHCT responses, there was no improvement in PFS or OS following Vel-Mel. This data supports the findings of the smaller prospective IFM study.

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.

A phase 1/2 of carfilzomib and melphalan conditioning for autologous stem cell transplantation for multiple myeloma (CARAMEL)

In this phase 1/2 study, carfilzomib was added to high-dose melphalan conditioning prior to autologous stem cell transplantation (ASCT) in patients with multiple myeloma that had been treated with ≤2 prior lines of therapy. Carfilzomib was escalated at doses of 27, 36, 45, and 56 mg/m2 on days -6, -5, -2, and -1 before ASCT in the phase 1 component of the study. In addition, all the patients received melphalan 100 mg/m2 on days -4 and -3. The primary endpoint of the phase 1 component was to identify the maximum tolerated dose, and the primary endpoint of the phase 2 component was the rates of complete response (≥CR) at 1 year after ASCT. The phase 1 dose escalation cohort included 14 patients, and 35 patients were included in the phase 2 cohort. The maximum tested dose was 56 mg/m2 (MTD). The median time from diagnosis to study enrollment was 5.8 (range 3.4-88.4) months, and 16% of patients had obtained a ≥CR prior to ASCT. The best response within 1 year after ASCT was a ≥ CR rate in 22% for the entire cohort, and 22% for patients treated at the MTD. The ≥VGPR rates improved from 41% before ASCT to 77% by 1 year after ASCT. One patient had a grade 3 renal adverse event, and renal function returned to baseline with supportive care. The rate of grade 3-4 cardiovascular toxicity was 16%. The addition of carfilzomib to melphalan conditioning was safe and resulted in deep responses after ASCT.

Survival outcomes following autologous stem cell transplant with melphalan 140mg/m2 versus 200mg/m2 preparative regimens in patients with multiple myeloma

The standard preparative regimen for autologous stem cell transplant (ASCT) in multiple myeloma (MM) is 200 mg/m2 of intravenous melphalan; however, a dose of 140 mg/m2 is often used when concerns exist related to patient age, performance status, organ function, and other factors. It is unclear whether a lower dose of melphalan impacts post-transplant survival outcomes. We performed a retrospective review of 930 patients with MM who underwent ASCT with 200 mg/m2 versus 140 mg/m2 melphalan. On univariable analysis, no difference in progression-free survival (PFS) was observed, however, an overall survival (OS) benefit was observed in patients receiving 200 mg/m2 melphalan (p = 0.04). Multivariable analyses showed patients receiving 140 mg/m2 faired no worse than those receiving 200 mg/m2. While a subset of younger patients with normal renal function may achieve superior OS with a standard dose of 200 mg/m2 melphalan, these findings suggest an opportunity to individualize the ASCT preparative regimen to optimize outcomes.

Revisiting the Role of Alkylating Agents in Multiple Myeloma: Up-to-Date Evidence and Future Perspectives

From the 1960s to the early 2000s, alkylating agents (e.g., melphalan, cyclophosphamide, and bendamustine) remained a key component of standard therapy for newly-diagnosed or relapsed/refractory multiple myeloma (MM). Later on, their associated toxicities (including second primary malignancies) and the unprecedented efficacy of novel therapies have led clinicians to increasingly consider alkylator-free approaches. Meanwhile, new alkylating agents (e.g., melflufen) and new applications of old alkylators (e.g., lymphodepletion before chimeric antigen receptor T-cell [CAR-T] therapy) have emerged in recent years. Given the expanding use of antigen-directed modalities (e.g., monoclonal antibodies, bispecific antibodies, and CAR-T therapy), this review explores the current and future role of alkylating agents in different treatment settings (e.g., induction, consolidation, stem cell mobilization, pre-transplant conditioning, salvage, bridging, and lymphodepleting chemotherapy) to ellucidate the role of alkylator-based regimens in modern-day MM management.

Methylene blue for intractable pain from oral mucositis related to cancer treatment: a randomized phase 2 clinical trial

BACKGROUND

Oral mucositis (OM) in patients receiving cancer therapy is thus far not well managed with standard approaches. We aimed to assess the safety and effectiveness of methylene blue (MB) oral rinse for OM pain in patients receiving cancer therapy.

METHODS

In this randomized, single-blind phase 2 clinical trial, patients were randomized to one of four arms: MB 0.025%+conventional therapy (CTx) (n = 15), MB 0.05%+CTx (n = 14), MB 0.1%+CTx (n = 15), or CTx alone (n = 16). Intervention groups received MB oral rinse every 6 h for 2 days with outcomes measured at days 1-2; safety was evaluated up to 30 days. The primary outcome measured change in the pain numeric rating scale (0-10) from baseline to day 2. Secondary outcome measured change in oral function burden scores from baseline to day 2, World Health Organization OM grades, morphine equivalent daily doses, and adverse events. The trial was registered with ClinicalTrials.gov ID: NCT03469284.

RESULTS

Sixty patients (mean age 43, range 22-62 years) completed the study. Compared with those who received CTx alone, those who received MB had a significant reduction of pain scores at day 2 of treatment (mean ± SD); 0.025%: 5.2 ± 2.9, 0.05%: 4.5 ± 2.9, 0.1%: 5.15 ± 2.6) and reduction of oral function burden scores (0.025%: 2.5 ± 1.55, 0.05%: 2.8 ± 1.7, 0.1%: 2.9 ± 1.60). No serious adverse events were noted, but eight patients reported burning sensation of the oral cavity with the first dose, and this caused one patient to discontinue therapy.

CONCLUSIONS

MB oral rinse showed significant pain reduction and improved oral functioning with minimal adverse effects.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT03469284.

Genome Instability in Multiple Myeloma: Facts and Factors

Multiple myeloma (MM) is a malignant neoplasm of terminally differentiated immunoglobulin-producing B lymphocytes called plasma cells. MM is the second most common hematologic malignancy, and it poses a heavy economic and social burden because it remains incurable and confers a profound disability to patients. Despite current progress in MM treatment, the disease invariably recurs, even after the transplantation of autologous hematopoietic stem cells (ASCT). Biological processes leading to a pathological myeloma clone and the mechanisms of further evolution of the disease are far from complete understanding. Genetically, MM is a complex disease that demonstrates a high level of heterogeneity. Myeloma genomes carry numerous genetic changes, including structural genome variations and chromosomal gains and losses, and these changes occur in combinations with point mutations affecting various cellular pathways, including genome maintenance. MM genome instability in its extreme is manifested in mutation kataegis and complex genomic rearrangements: chromothripsis, templated insertions, and chromoplexy. Chemotherapeutic agents used to treat MM add another level of complexity because many of them exacerbate genome instability. Genome abnormalities are driver events and deciphering their mechanisms will help understand the causes of MM and play a pivotal role in developing new therapies.

Gastrointestinal toxicity of high-dose melphalan in autologous hematopoietic stem cell transplantation: identification of risk factors and a benchmark for experimental therapies

Gastrointestinal side effects are the dose-limiting toxicity of high-dose melphalan (HDM) in autologous hematopoietic stem-cell transplantation, but there are limited contemporary data on the incidence and severity of gastrointestinal toxicity associated with this regimen. We retrospectively studied 100 consecutive patients who received HDM alone or in combination with other conditioning agents. Patients had a median age of 56 (range 20-73); underlying diseases were myeloma (42%), lymphoma (42%), or amyloidosis (16%) and melphalan dosages were 200 (40%), 140 (59%), or 100 mg/m² (1%). Ninety-seven percent of patients experienced diarrhea with a range of 1-18 bowel movements per day, 88% developed nausea, and 60% experienced vomiting. Abdominal CT scans rarely altered patient management, but stool studies were useful in identifying a treatable infectious source. Grade ≥ 2 diarrhea was associated with longer duration of diarrhea, longer length of stay, worse hypoalbuminemia, higher use of antibiotics, abdominal imaging, electrolyte repletions, and anti-diarrheal agents. Risk factors for severe diarrhea were female sex, melphalan dose, age > 50, creatinine clearance < 60 ml/min, and having a plasma cell neoplasm as opposed to lymphoma. Female sex was also associated with more severe nausea and vomiting. In summary, diarrhea remains an important toxicity of HDM and novel therapies for chemotherapy-induced diarrhea for patients undergoing stem-cell transplantation are needed. Grade 2 or higher diarrhea is associated with significant clinical consequences and should be used as the primary endpoint in prospective clinical trials.

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.

Stem-cell transplantation in multiple myeloma: how far have we come?

High-dose therapy (HDT) and autologous stem-cell transplantation (ASCT) has historically been an essential part of multiple myeloma (MM) management since early studies demonstrated its efficacy in relapsed disease, and subsequent phase III trials demonstrated better responses and improved survival with this modality compared with standard chemotherapy. With further advances in the MM treatment landscape, including the development of potent novel agents, there has been an increasing debate around various aspects of ASCT, including the optimal timing, role of single versus tandem ASCT, and the practice of consolidation and maintenance therapy post-ASCT. Routine incorporation of the novel agents at each of the treatment phases, induction, consolidation when used, and maintenance has led to better responses as reflected by increasing rates of minimal residual disease (MRD) negativity, longer progression-free survival (PFS) with improvement in overall survival (OS) and in some of the trials. The phase III trials over the last decade have provided significant clarity on the current approach, and have raised important questions regarding the applicability of this modality in all patients. This review aims to summarize the latest literature in the field and discusses how these findings impact the practice of ASCT today.

Current status of autologous stem cell transplantation for multiple myeloma

More than 30 years after its introduction, autologous stem cell transplantation (ASCT) remains the standard of care for young patients with newly diagnosed multiple myeloma. Not only did the arrival of novel agents such as immunomodulatory drugs (IMiDs), proteasome inhibitors (PI) and monoclonal antibodies not replace ASCT, instead they solidified its central role as standard of care. Novel agent use is now inarguably essential in induction, maintenance, and possibly consolidation. In light of these new advancements, new challenges arise in deciding on optimal practice. Who is most suited to undergo ASCT? Is there an age threshold that should not be surpassed? Should transplantation be embarked on early or is it reasonable to delay it? What are the optimal induction, consolidation, and maintenance therapies? What is the role of tandem transplantation in the era of novel agents and where do patient-specific cytogenetics come into the equation when deciding on treatment? These are some of the questions addressed in this review which we will attempt to answer with the latest currently available data.

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.

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.

Efficacy and safety of autologous hematopoietic cell transplantation in elderly patients with multiple myeloma: a retrospective national multi-site cohort study

We aimed to test the efficacy and toxicity of autologous hematopoietic cell transplant (HCT) in Multiple Myeloma (MM) patients aged ≥65 years compared to patients aged 60-64. Two hundred twenty consecutive patients (age ≥65, n = 87) with MM aged 60 and above, who underwent HCT as part of an upfront MM treatment, at four Israeli centers between 2000 and 2014 were included. A melphalan dose of 200 mg/m² was more frequent in the 60-64 age group vs. the ≥65 age group (77 vs. 57%, p = 0.002). There were no differences between groups in median day of neutrophil engraftment, incidence of infections, grades 3-4 mucositis, cardiovascular events, or non-relapse mortality at 100 days post HCT (4.7, vs. 5%, p = 0.9). A similar rate of improvement in response level was observed (36, vs. 35%, p = 0.87). At 3 years post HCT progression-free survival (PFS) was higher in the 60-64 age group (42 vs. 29%, p = 0.04); however, it was no longer so after adjustment for disease status prior to HCT (p = 0.49). In a Multivariate analysis, melphalan doses and age did not predict PFS. There was no difference in overall survival (OS) between age groups (p = 0.2). We conclude that toxicity profile, response, PFS, and OS of HCT in aged ≥65 patients with myeloma is similar to patients aged 60-64.

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.

A phase 1 study of bendamustine and melphalan conditioning for autologous stem cell transplantation in multiple myeloma

Bendamustine has efficacy in multiple myeloma with a toxicity profile limited to myelosuppression. We hypothesized that adding bendamustine to autologous stem cell transplant conditioning in myeloma would enhance response without significant additional toxicity. We conducted a phase 1 trial adding escalating doses of bendamustine to the current standard conditioning of melphalan 200 mg/m(2). Twenty-five subjects were enrolled into 6 cohorts. A maximum tolerated dose was not encountered and the highest dose level cohort of bendamustine 225 mg/m(2) + melphalan 200 mg/m(2) was expanded to further evaluate safety. Overall, there was no transplant related mortality and only one grade 4 dose-limiting toxicity was observed. Median number of days to neutrophil and platelet engraftment were 11 (range, 9 to 14) and 13 (range, 10 to 21), respectively. Disease responses at day +100 posttransplantation were progression in 5 (21%), partial response in 1 (4%), very good partial response in 7 (33%), complete response in 1 (4%), and stringent complete response in 9 (38%). Six patients (24%) with pre-existing high-risk disease died from progressive myeloma during study follow-up, all at or beyond 100 days after autologous stem cell transplant. Bendamustine up to a dose of 225 mg/m(2) added to autologous stem cell transplantation conditioning with high-dose melphalan in patients with multiple myeloma did not exacerbate expected toxicities.