Prognostic Significance of Initial Serum Albumin and 24 Hour Daily Protein Excretion before Treatment in Multiple Myeloma

Clinical Pharmacokinetics and Pharmacodynamics of Daratumumab

Daratumumab is a fully human, monoclonal immunoglobulin G1 and a first-in-class CD38-targeting drug approved by the US Food and Drug Administration for the treatment of patients with relapsed/refractory and newly diagnosed multiple myeloma or newly diagnosed light-chain amyloidosis. CD38 is heavily expressed on malignant myeloma cells, and daratumumab exerts anti-myeloma activity via immune-mediated mechanisms, direct induction of apoptosis, and immunomodulation. Daratumumab is used as monotherapy or in combination with standard-of-care myeloma therapies, including proteasome inhibitors, immunomodulatory agents, DNA-alkylating agents, and corticosteroids. Following an intravenous infusion, daratumumab exhibits nonlinear pharmacokinetics (PK), as clearance decreases with higher doses and over time because of target-mediated effects. Dosing schedules vary depending on indications and co-administered drugs, but generally daratumumab is administered weekly for 6-9 weeks followed by a less frequent dosing regimen, once every 2-4 weeks. Daratumumab exposure is strongly correlated with efficacy, and the exposure-efficacy relationship follows a maximal effect model, whereas exposure is not correlated with safety endpoints. The approved dose of 16 mg/kg of daratumumab results in the saturation of 99% of the target at the end of weekly dosing in most patients, and high target saturation is maintained over time during the less frequent dosing schedule. Infusion-related reactions are frequently observed in patients given daratumumab, particularly with the first infusion, thus prompting long durations of infusion (~ 7 h) and splitting of the first dose across 2 days. This led to the development of a subcutaneous delivery formulation for daratumumab (Dara-SC). Dara-SC provides a similar efficacy and safety profile to intravenous daratumumab (Dara-IV) but has a much lower rate of infusion-related reactions and a shorter infusion time. Exposure-response relationships for efficacy and safety endpoints were similar between Dara-SC and Dara-IV, and co-administered drugs with either Dara-IV or Dara-SC do not significantly affect daratumumab PK. Except for baseline myeloma type and albumin level, none of the other investigated disease and patient characteristics (renal/hepatic function, age, sex, race, weight, Eastern Cooperative Oncology Group performance status) was identified to have clinically relevant effects on exposure to daratumumab monotherapy or combination therapy regimens. Dara-IV exposure was significantly lower in patients with immunoglobulin G myeloma compared with patients with non-immunoglobulin G myeloma (p < 0.0001) and in patients with a lower albumin level, whereas the overall response rate was similar regardless of the myeloma type and albumin level. Daratumumab dose adjustment is not currently recommended based on disease and patient characteristics.

Plateau is a prognostic factor of lenalidomide therapy for previously treated multiple myeloma

The plateau phase emerging during the treatment of multiple myeloma (MM) is known to last steadily for a certain period, even without treatment. Therefore, the treatment started at plateau phase is expected to be associated with a better outcome. In this study, this hypothesis was evaluated retrospectively for previously treated MM patients in Kansai Myeloma Forum database who received lenalidomide (LEN) with or without dexamethasone for the first time. Disease stability index (DSI) was defined as (maximum - minimum values of M protein during the 90 days before the start of LEN) divided by M-protein values at the start of LEN. The patients were classified into three groups: stable (S), DSI ≤ 0.25; increasing (I), DSI > 0.25 with increasing M protein; decreasing (D), DSI > 0.25 with decreasing M protein. In univariate analysis of 352 patients, DSI group "I", non-IgG type, serum albumin<3.5 g/dL, and age≥70 were statistically significant prognostic factors for both progression-free survival and overall survival. In multivariate analysis, the former 3 risk factors were statistically significant for poor overall survival. Thus, DSI is an independent prognostic factor for the treatment with LEN for previously treated MM.

Preoperative Hyponatremia And Hypocalcemia Predict Poor Prognosis In Elderly Gastric Cancer Patients

Background

Hyponatremia and hypocalcemia are common in patients with cancer, but their prognostic impact in patients who underwent gastric cancer (GC) surgery has not been investigated. Therefore, this study aimed to determine the postoperative prognostic impact of hyponatremia and hypocalcemia in patients undergoing curative gastrectomy by age group.

Materials and methods

GC patients preoperatively diagnosed with hyponatremia or hypocalcemia who underwent elective radical gastrectomy were retrospectively evaluated. The patients were divided into the elderly group (≥60 years) and the young group (<60 years), and then further based on their sodium and calcium levels. The effect of preoperative hyponatremia or hypocalcemia on postoperative complications (PCs) by age was determined using univariate and multivariate analyses. Overall survival (OS) was compared between the two groups using log rank test and Cox proportional hazards regression.

Results

Of the 842 patients evaluated, 36 (4.3%) were categorized into the younger hyponatremia group; 64 (7.6%), the elderly hyponatremia group; 48 (5.7%), the young hypocalcemia group; and 128 (15.2%), the elderly hypocalcemia group. Hyponatremia (P=0.001) and hypocalcemia (P=0.038) were independent risk factors for PCs in the elderly group. Further, hypocalcemia (hazard ratio (HR), 0.676; P=0.037) was independently associated with shorter OS.

Conclusion

Preoperative hyponatremia and hypocalcemia predict poor outcomes in the elderly, but not in young GC patients. Further, hyponatremia and hypocalcemia in elderly GC patients should be corrected in the earliest time possible to obtain better clinical outcomes.

Differential expression of serum proteins in multiple myeloma

The exact cause instigating multiple myeloma (MM) has not been fully elucidated, and the disease has a median survival of 6 months without any treatment. To identify potential biomarkers of MM, serum proteins reflecting alteration in their proteomes were analyzed in 6 patients with MM compared with 6 healthy controls using two-dimensional electrophoresis (2-DE) and matrix-assisted laser desorption/ionization time-of flight mass spectrometry. The most notable differentially expressed proteins were validated by immunoblotting and changes in mRNA expression were evaluated by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). A total of 11 differentially expressed protein spots were found. The expression levels of 7 proteins [Immunoglobulin heavy constant µ; proto-oncogene diffuse B-cell lymphoma (DBL2); 26S protease regulatory subunit 4 (P26s4); serum albumin; haptoglobin; and two unknown proteins with isoelectronic point (pI) of 6.41 and molecular weight of 35.4 kDa, and pI of 8.05 and molecular weight of 27.4 kDa, respectively] were downregulated in MM compared with healthy controls. Expression of gel actin-related protein 2/3 complex subunit 1A (ARPC1A); immunoglobulin heavy constant γ 1; fibrinogen α chain (FGA) fragment D; and zinc finger protein 70 were increased in serum of MM patients. Protein expressions of ARPC1A, FGA, P26s4 and DBL2 were measured by immunoblotting in an independent cohort of 12 MM patients and 10 healthy controls. RT-qPCR analysis demonstrated that ARPC1A expression only mimicked protein expression, whereas FGA, PSMC1 (encoding P26s4) and MCF2 (encoding DBL2) did not exhibit significant changes in mRNA expression between control and MM samples. These proteins represent putative serological biomarkers for patients with MM.

Unsuppressed serum albumin levels may jeopardize the clinical relevance of the international staging system to patients with light chain myeloma

The international staging system (ISS) is the most commonly used risk-stratification system for patients with multiple myeloma (MM) and is determined by serum albumin and β2-microglobulin levels. In the two determinants, β2-microglobulin levels are frequently observed to be elevated in patients with myeloma, particularly in those with renal impairment. In comparison with patients with intact immunoglobulin myeloma, patients with LC myeloma do not necessarily show decreased levels of serum albumin. The clinical impact of ISS in patients with LCMM, in particular the distinction between ISS I and II, may be complicated due to non-decreased levels of serum albumin in both stages. Accordingly, we have attempted to assess clinical relevance of the ISS in patients with LC myeloma. The clinical data of 1899 patients with MM diagnosed between January 2001 and December 2012 were collected from 38 affiliated hospitals of the Japanese Society of Myeloma. Significant difference was not found between stage I (n = 72) and stage II (n = 92) in LC myeloma patients (n = 307). The mean serum albumin concentration of patients with LC myeloma was within the reference range but higher than that of patients with IgG + IgA myeloma (n = 1501), which complicates the distinction between ISS stage I and II myeloma. Patients with LC myeloma had low frequencies of t(4; 14) and high frequency of elevated lactate dehydrogenase, and despite a relevant amount of missing data in our registry (R-ISS stage I; n = 11, stage II; n = 32, and stage III: n = 18), the information included in the R-ISS scoring system seems to be more accurate than ISS to obtain a reliable risk stratification approach in non-ISS stage III LC myeloma patients.

Impact of hemodialysis on the prognosis of multiple myeloma: A nationwide population-based study and single-institute analysis

Myeloma-associated kidney disease (MRKD) occurs in ≤40% patients with multiple myeloma (MM). The impact of hemodialysis (HD) on patients with MM was investigated. Between 2000 and 2010, a total of 1,610 patients in Taiwan were enrolled from the National Health Institute Research Database. MM was an independent risk factor for HD following adjustment via multivariate logistic regression analysis (adjusted hazard ratio, 7.347; 95% confidence interval, 6.156-8.768; log-rank test, P<0.001). In addition, a notable decrease in survival rate was determined in patients with MM who underwent HD in the first year since diagnosis of MM. A total of 198 (61.49%) patients received HD in the first year. Patients with MM with a lower frequency of HD in the first year had a relatively good prognosis. The present study confirmed that MM was a risk factor for HD. Significant early mortality in the first year was determined in patients with MM who underwent HD; however, renal recovery following therapeutic management was a prognostic factor. In addition to anti-myeloma therapy, early initiation of HD was beneficial following risk stratification of MRKD; however, an increased probability of recovery of renal function and discontinuation of dialysis, was demonstrated in patients with MM following HD, compared with patients with MM without HD.