Safety and Pharmacokinetics of Bendamustine Rapid-Infusion Formulation

A phase I/II study of 10-min dosing of bendamustine hydrochloride (rapid infusion formulation) in patients with previously untreated indolent B-cell non-Hodgkin lymphoma, mantle cell lymphoma, or relapsed/refractory diffuse large B-cell lymphoma in Japan

Purpose

This phase I/II clinical study was conducted to examine the safety, tolerability, pharmacokinetics, and efficacy of 10-min dosing of bendamustine in patients with previously untreated indolent B-cell non-Hodgkin lymphoma (iNHL) or mantle cell lymphoma (MCL) (Group 1) and patients with relapsed/refractory diffuse large B-cell lymphoma (rrDLBCL) (Group 2).

Methods

Rituximab 375 mg/m² was administered intravenously every 28 days to Group 1 patients on day 1 and every 21 days to Group 2 patients on day 1. Bendamustine 90 mg/m²/day was administered to the former on days 1 and 2; bendamustine 120 mg/m²/day was administered to the latter on days 2 and 3. Each regimen was delivered up to six cycles for both groups. The primary endpoints were safety and tolerability in Groups 1 and 2, respectively.

Results

Among 37 enrolled patients, safety was assessed in 36. In Group 1 (n = 30), 27 patients (90%) had follicular lymphoma. Adverse events (AEs) were observed in all 30 patients in Group 1. Dose-limiting toxicities were observed in two of six patients in Group 2. Common AEs included lymphocyte count decreased (86.7%, 100%). In Group 1, overall response and complete response rates were 93.1% (95% confidence interval [CI] 77.2–99.2%) and 75.9% (95% CI 56.5–89.7%), respectively. The C_max and AUC of bendamustine tended to be higher in Group 2 than in Group 1.

Conclusions

This study showed that bendamustine is safe, well-tolerated and effective for patients with previously untreated iNHL, MCL or rrDLBCL. Pharmacokinetic data were equivalent to those obtained outside of Japan.

Registration numbers

Registration NCT03900377; registered April 3, 2019.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00280-022-04442-2.

Obinutuzumab in Combination with Chemotherapy Enhances Direct Cell Death in CD20-Positive Obinutuzumab-resistant Non-Hodgkin Lymphoma Cells

Follicular lymphoma commonly recurs and is difficult to cure. Obinutuzumab is a humanized glycoengineered type II anti-CD20 antibody with a mode of action that includes induction of antibody-dependent cellular cytotoxicity, antibody-dependent cellular phagocytosis, and direct cell death. There is no evidence on the effectiveness of retreatment with obinutuzumab in patients with prior obinutuzumab treatment. Using obinutuzumab-induced direct-cell-death-resistant cells, we investigated the efficacy of obinutuzumab retreatment in combination with chemotherapeutic agents used in follicular lymphoma treatment. Human non-Hodgkin lymphoma SU-DHL-4 cells were sustainably exposed to obinutuzumab in vitro, and 17 resistant clones expressing CD20 and showing 100-fold higher IC₅₀ of obinutuzumab than parental cells were established. The growth inhibition effect of obinutuzumab in combination with bendamustine, 4-hydroperoxy-cyclophosphamide, doxorubicin, vincristine, or prednisolone was estimated using an interaction index based on the Bliss independence model. For each clone, there were various combinations of obinutuzumab and chemotherapeutic agents that showed supra-additive effects. Obinutuzumab combined with doxorubicin enhanced caspase-dependent apoptosis and growth inhibition effect. Obinutuzumab combined with prednisolone enhanced DNA fragmentation and G₀-G₁ arrest. These combinations also had an antitumor effect in mouse xenograft models. Our results indicate that retreatment with obinutuzumab, when it is combined with chemotherapeutic agents, is effective in the CD20-positive obinutuzumab-induced direct-cell-death-resistant cells.

Budgetary Impact of Bendamustine Ready-to-Dilute Products in Chronic Lymphocytic Leukemia and Non-Hodgkin Lymphoma to a United States Infusion Facility

Background

Bendamustine hydrochloride (BND HCl) is indicated for first-line treatment of chronic lymphocytic leukemia (CLL) and rituximab-refractory indolent non-Hodgkin lymphoma (iNHL). There are two ready-to-dilute (RTD) formulations of BND HCl on the US market: a large-volume, long-duration infusion (BND-L) and a small-volume, short-duration infusion (BND-S). It is estimated that the shorter duration infusion could result in cost savings to infusion facilities.

Objective

Estimate the one-year budget impact between BND-S and BND-L for use in the treatment of CLL and iNHL when all current BND-L utilization is replaced with BND-S, from the US infusion facility perspective.

Methods

An illustrative budget impact model estimated the change in costs associated with a projected increase from 50% to 100% market share for BND-S. The model included CLL and iNHL patient populations. Budgetary costs reflected facility expenditures on drug acquisition and administration based on recommended dosing for BND-S and BND-L. The base-case model assumptions and inputs were derived from scientific literature and publicly available resources. The total budget impact was calculated annually, along with the differences in per patient cost; one-way sensitivity analyses were conducted.

Results

Per-patient savings with BND-S use after the utilization shift were estimated at $2812.24 for CLL and $4769.01 for iNHL. Across both indications, the total annual incremental savings after the utilization shift were estimated at $452,209 for 250 CLL and iNHL patients in a 10,000-patient infusion facility, resulting in cost savings of $150.74 per BND HCI patient per month and $1808.84 per BND HCI patient per year. The model was sensitive to changes in proportion of patients receiving BND HCI infusions for CLL and iNHL, patient body surface area, and BND-S wholesale acquisition cost.

Conclusion

This analysis estimated over $450,000 in annual savings for a 10,000-patient chemotherapy infusion facility following a utilization shift from 50% use of each RTD product to 100% use of BND-S in CLL and iNHL patients, driven by lower acquisition costs for BND-S and lower administration labor costs associated with rapid infusion.