Pharmacokinetics-directed Intravenous Busulfan Combined With High-dose Melphalan and Bortezomib as a Conditioning Regimen for Patients With Multiple Myeloma

Busulfan, melphalan and carfilzomib high-dose chemotherapy and autologous haematopoietic stem cell transplantation in multiple myeloma

The standard of care for fit, newly diagnosed multiple myeloma patients includes induction therapy followed by consolidative high-dose chemotherapy with melphalan and autologous stem cell transplant (AHSCT). Intensified preparative regimens, such as busulfan and melphalan (BuMel), have shown promise to lengthen progression-free survival (PFS). We previously reported that the addition of bortezomib to BuMel improved PFS compared to melphalan alone in CIBMTR-matched controls. We now integrate the second-generation protease inhibitor, carfilzomib, before and after BuMel (BuMelCar) in a phase I/II trial with carfilzomib. Patients with NDMM, relapsed/refractory MM (RRMM) and those failing prior AHSCT were eligible. Primary end-points were safety and tolerability. Secondary end-points included minimal residual disease negativity rates, PFS and OS. The study enrolled 19 patients. 73% were high risk either due to R-ISS III status, adverse genetics or relapsed after prior AHSCT. The maximum tolerated dose (MTD) of carfilzomib was determined to be 36 mg/m2. Noted grade 3 toxicities were febrile neutropenia (79%), mucositis (21%) and diarrhoea (16%). The 2-year PFS for the whole cohort and MTD was 89% and 100% respectively. 80% of all patients and 82% of patients in the MTD cohort achieved MRD negativity. Further studies regarding this regimen are planned.

Autologous stem cell transplantation in multiple myeloma patients with renal impairment

Renal impairment (RI) used to exclude multiple myeloma (MM) patients from autologous stem cell transplantation (ASCT) for safety concerns. Here, we retrospectively reviewed 34 consecutively transplanted patients with creatinine clearance < 60 ml/min at ASCT in recent 5 years at our institution. Busulfan/cyclophosphamide and high-dose melphalan were both employed as conditioning regimens. We found 62% grade 1-2 oral mucositis, 12% grade 3 oral mucositis, 48% grade 3 infection, 8% grade ≥ 4 infection, 50% grade 1 transient creatinine increase, 15% cardiac adverse events, and 12% engraftment syndrome. One case of secondary platelet graft failure and 1 case of transplantation-related mortality were observed. Interleukin-6 concentration was elevated among patients with increased body temperature and/or N-terminal pro-brain natriuretic peptide during engraftment, and close monitoring of these markers may help to predict susceptibility to cardiac events and engraftment syndrome. Adverse events occurred frequently, but the majority were manageable in this cohort. ASCT would further deepen the anti-myeloma efficacy and slightly ameliorated renal function. With a median follow-up of 26.2 months post transplantation (range: 1.6-74.8 months), the median progression-free survival (PFS) and overall survival (OS) post-transplantation of patients undergoing first-line transplantation were not reached; the median PFS post-transplantation of patients undergoing rescue transplantation was 19.2 months and the median OS was not reached.

Autologous stem cell transplant for multiple myeloma: Impact of melphalan dose on the transplant outcome

We evaluated impact of melphalan dose on transplant outcomes for multiple myeloma. Between 1995 and 2019 459 consecutive patients received a transplant; 69(15%) received melphalan ≤150 mg/m2 (Mel 150 cohort) and 390 (85%) melphalan 200 mg/m2 (MEL 200 cohort). The primary outcome was overall survival (OS) from the date of transplant. Progression-free survival (PFS), engraftment, transplant response, and cumulative relapse at 2 years were secondary outcome measures. Patients in Mel 150 cohort had adverse clinical and laboratory parameters at base line. Transplant response was better for Mel 200 cohort (p < 0.024). Median OS at a median follow-up of 88 months was similar in the two cohorts; 100 Vs 102 months (Mel 200), p = 0.817. Median PFS (60.0 Vs 53 months, p = 0.746), relapse at two years (32.4% Vs 30.9%, p = 0.745) and grade 3-4 mucositis (p = 0.823) were similar. Initial treatment prepares patients better for subsequent similar transplant outcomes despite differences in baseline characteristics.

Chemotherapy and dysphagia: the good, the bad, the ugly

PURPOSE OF REVIEW

Dysphagia is a debilitating, depressing and potentially life-threatening complication in cancer patients that is likely underreported. The purpose of this review is to critically synthesize the current knowledge regarding the impact of chemotherapeutic regimens on swallowing function.

RECENT FINDINGS

Those patients with cancers involving the aerodigestive tract, head and neck cancer and oesophageal cancer are at highest risk of developing dysphagia. The most common dysphagia causing toxicity of chemotherapeutic agents is mucositis/stomatitis. The use of cisplatin is correlated with increased incidence of mucositis. Similarly, the addition of melphalan is also associated with worsening mucositis and dysphagia. In some cases of oesophageal cancer, thyroid cancer, metastatic lung or breast cancer the use of chemotherapy can improve swallow function as obstructive lesions are reduced.

SUMMARY

There is limited literature regarding the role of chemotherapy in the development or treatment of dysphagia. Most dysphagia that occurs during cancer treatment is attributable to radiation or the synergistic effect of radiation and chemotherapy. Patients with disordered swallowing prior to treatment have the greatest risk of developing posttreatment dysphagia. Studies are needed to determine whether acute inflammation associated with oropharyngeal mucositis predisposes for late dysphagia.

Busulfan, melphalan, and bortezomib compared to melphalan as a high dose regimen for autologous hematopoietic stem cell transplantation in multiple myeloma: long term follow up of a novel high dose regimen

Melphalan at a dose of 200 mg/m² (MEL200) remains the standard high dose therapy before autologous stem cell transplantation (ASCT) for multiple myeloma (MM). Intensifying the high dose regimen has shown promising results. We report here 7-year follow up of our novel high dose regimen of busulfan and melphalan followed by bortezomib (BuMelVel). Forty-three MM patients received BuMelVel high dose therapy with pharmacokinetic adjusted busulfan. Outcomes were compared to a matched control cohort from the CIBMTR database (n = 162) receiving MEL200. The primary endpoint was progression free survival. Five year PFS was 47% v 30% (95% CI; 32-62) in favor or the BuMelVel group (95% CI; 23-37) (p = 0.05). In multivariate analysis for PFS, BuMelVel (HR 0.65; 95% CI 0.44-0.97)(p = 0.036) was predictive. Similar to recent reports of double alkylator therapy, although depth of response was similar between the BuMelVel group and MEL200, the BUMELVEL group experienced an improved PFS.

Tolerance, Kinetics, and Depth of Response for Subcutaneous Versus Intravenous Administration of Bortezomib Combination in Chinese Patients With Newly Diagnosed Multiple Myeloma

BACKGROUND

Peripheral neuropathy (PN) is an important toxicity that limits the use of bortezomib (Btz). Attempts to reduce PN have included its subcutaneous (SC) administration.

PATIENTS AND METHODS

We retrospectively analyzed 307 patients with newly diagnosed multiple myeloma from a single Chinese center, receiving Btz-based regimens administered either via SC injection (SC group, n = 167) or intravenous (IV) infusion (IV group, n = 140). The efficacy and safety of Btz administration via SC and IV were then compared.

RESULTS

Most baseline characteristics were similar between these 2 groups. A lower frequency of adverse events, especially grade ≥ 3 PN (P = .002), was observed in the SC group compared with the IV group. The estimated median Btz dosage when PN developed was higher (20.8 mg/m2 vs. 15.6 mg/m2), and fewer patients reduced or discontinued Btz owing to adverse events in the SC group compared with the IV group. The overall response rate (≥ partial response [PR]) was comparable (94.8% vs. 96.2%). However, patients in the IV group required fewer cycles to achieve PR, whereas a larger proportion of patients in the IV group achieved ≥ very good PR. After a median follow-up of 23 months (range, 1-84 months), no significant difference in median progression-free survival (not arrived vs. 33.0 ± 2.735 months) and overall survival (not arrived vs. 56.0 months) was noted.

CONCLUSION

SC Btz is associated with better tolerance; however, IV administration achieves a faster and deeper response in Chinese patients with newly-diagnosed multiple myeloma.