A phase 1b/2 study evaluating efficacy and safety of MP0250, a designed ankyrin repeat protein (DARPin) simultaneously targeting vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF), in combination with bortezomib and dexamethasone, in patients with relapsed or refractory multiple myeloma.

MP0250 is a designed ankyrin repeat protein that specifically inhibits both vascular endothelial growth factor A (VEGF-A) and hepatocyte growth factor (HGF), aiming at potentiating cancer therapy by disrupting the tumour microenvironment. Encouraging results from a phase 1 trial of MP0250 in patients with solid tumours prompted further investigation in multiple myeloma (MM) as both MP0250 targets are reported to be drivers of MM pathogenesis. In this open-label, single-arm phase 1b/2 study (NCT03136653) in patients with proteasome inhibitor- and/or immunomodulatory drug-relapsed or refractory MM, MP0250 was administered every 3 weeks with standard bortezomib/dexamethasone regimen. Thirty-three patients received at least one dose of MP0250. The most frequent treatment-related adverse events were arterial hypertension (58.1%), thrombocytopenia (32.3%), proteinuria (29.0%) and peripheral oedema (19.4%). Of the 28 patients evaluable for response (median age: 60 [range 44-75]), nine achieved at least partial response, corresponding to an overall response rate of 32.1% (95% confidence interval [CI]: 17.9%, 50.7%), with a median duration of response of 8 months (95% CI 5-NR). An additional three patients achieved minimal response and nine stable diseases as the best overall response. Overall median progression-free survival was 4.2 months (95% CI 1.9-7.1). These findings are in line with the results of recent trials testing new agents on comparable patient cohorts and provide initial evidence of clinical benefit for patients with refractory/relapsed MM treated with MP0250 in combination with bortezomib/dexamethasone. Further clinical evaluation in the emerging MM treatment landscape would be required to confirm the clinical potential of MP0250.

Haemodynamic Forces: Emerging Markers of Ventricular Remodelling in Multiple Myeloma Cardiovascular Baseline Risk Assessment.

Multiple myeloma (MM) affects a population with a high prevalence of cardiovascular (CV) disease. These patients benefit from an accurate CV risk evaluation in order to choose the safest drug regimen. Haemodynamic forces (HDFs) analysis allows for the earlier detection of myocardial damage compared with standard markers; the role played by MM in HDFs alteration, with or without the influence of hypertension, is yet to be studied. Therefore, we aimed to identify differences in HDFs analysis in patients with MM, hypertension or both versus normotensive non-oncologic subjects. A total of 173 patients (MM hypertensive patients, MMHT; MM normotensive patients, MMNT; non-oncologic hypertensive patients, CoHT; and non-oncologic normotensive patients, CoNT) underwent transthoracic echocardiography for HDFs analysis and pulse wave velocity (PWV) assessment. Hypertensive patients (MMHT, CoHT) showed decreased ejection fraction (EF), global longitudinal strain (GLS) and HDFs values compared with CoNT, whereas ventricular mass (LVMi) and PWV increased. MMNT displayed a significant reduction in systolic HDFs (p < 0.006) and systolic ejection HDFs (p < 0.008) compared with CoNT, without significant change in EF, GLS, LVMi or PWV. In conclusion, MM leads to ventricular remodelling regardless of hypertension; HDFs application for MM patients could help detect early myocardial damage, especially in patients receiving cardiotoxic drugs.

A real-life study of daratumumab combinations in newly diagnosed patients with light chain (AL) amyloidosis.

Daratumumab-based regimens are the new standard of care for newly diagnosed patients with AL amyloidosis based on the results of the ANDROMEDA study. However, real-world data on daratumumab efficacy in upfront therapy in unselected patients are scanty. In the framework of a prospective observational study, we investigated the efficacy and safety of daratumumab in 88 newly diagnosed patients, including subjects with IIIb cardiac stage (26%) or myeloma defining events (29%). Daratumumab was administered with bortezomib in 50 (56%) patients, lenalidomide in 31 (35%), and monotherapy in 7 (8%). The rate of serious adverse events was low (16%). The overall hematologic response rate was 75% with 52 (59%) patients attaining at least a very good partial response (VGPR) at six months. Amongst patients evaluable for organ response, the rate of cardiac and renal responses at 6 months was 31% and 21%, respectively. Comparing stage IIIb patients with the remaining ones, the rate of profound hematologic response was not significantly different (≥VGPR 57% vs. 59%, p 0.955) likewise the rate of cardiac (33% vs. 30%, p 0.340) and renal (40% vs. 16%, p 0.908) responses. Daratumumab-based regimens demonstrated to be safe and effective in treatment-naïve AL amyloidosis even in advanced stage disease.

Belantamab mafodotin in triple-refractory multiple myeloma patients: A retro-prospective observational study in Italy.

Belantamab mafodotin is the first-in-class antibody-drug conjugates targeting B-cell maturation antigen to have demonstrated effectiveness in triple-class refractory multiple myeloma (TCR-MM) patients. We performed a retrospective study including 78 TCR patients, with at least four prior lines of therapy (LOTs), who received belantamab mafodotin within named patient program and expanded access program in Italy between 2020 and 2022. Median age was 65 years (range 42-86 years), ECOG performance status was ≥1 in 45% of patients. Overall, a clinical benefit was obtained in 36 out of 74 evaluable patients (49%), with 43%, 28%, and 13.5% achieving at least partial response, very good partial response, and complete response, respectively. After a median follow-up of 12 months (range 6-21 months), median duration of response, progression-free survival (PFS), and overall survival (OS) were 14, 5.5, and 12 months, respectively. Age >70 years, good performance status and response were associated with longer PFS and OS. Keratopathy occurred in 58% of patients (G3 2.5%), corneal symptoms in 32% (G3 1.2%) and a reduction in visual acuity in 14%. Grade 3 thrombocytopenia occurred in 9% of patients. Only 3% of patients discontinued belantamab mafodotin because of side effects. This real-life study demonstrated significant and durable responses of belantamab in TCR-MM patients with four prior LOTs, otherwise ineligible for novel immunotherapies.

Risk of Infection in Patients With Multiple Myeloma Treated With T-Cell Redirecting Approaches: A Call Out for Clinicians.

T-cell redirecting therapies such as chimeric antigen receptor T-cells and bispecific antibodies, are emerging as a novel class of immunotherapeutic agents for treatment of relapsed refractory multiple myeloma (MM). Their use is associated with an increased risk of infectious adverse events, fostered by cytopenias, hypogammaglobulinemia and T-cell exhaustion. Multiple ongoing clinical trials and real-world studies are investigating safety of T-cell therapy, highlighting the need for strategies to prevent and monitor the risk of infection. Recommended measures for risk mitigation include intravenous immunoglobulin supplementation, adequate prophylaxis therapy, vaccination and careful assessment for early diagnosis and treatment of infection. Here, we summarize available data on the risk of infections with approved and under development T-cell redirecting therapies for the treatment of MM.

Anti-BCMA CAR-T cell-based therapies and bispecific antibodies in the immunotherapy era: are we ready for this?

INTRODUCTION: Therapeutic strategies against multiple myeloma (MM) have evolved dramatically in recent decades, with unprecedent results in the treatment landscape, culminating in the recent incorporation of novel agents in the anti-myeloma armamentarium. AREAS COVERED: BCMA represents one of the most promising targets in MM and currently available immune approaches, either approved or under active investigation, are clearly showing their greater potential over standard regimens. In this context, immunotherapies based on chimeric antigen receptor (CAR)-engineered T-cells and bispecific antibodies (BsAbs) have taken center stage, being the ones that are yielding the most promising results in clinical trials. This review focuses on the current landscape of BsAbs and CAR-T, summarizing the latest advances and possible future developments. EXPERT OPINION: CAR-T and BsAbs anti-BCMA strategies represent breakthrough therapies against MM. However, their inclusion in clinical practice is almost feared, due to the associated limitations, some of which have been addressed here. Meanwhile, all the efforts should be focused on individualizing and choosing the most suitable candidates for each treatment and to understand how to combine, or sequence, these therapies to improve efficacy and minimize toxicity, especially for those patients with limited available treatment options.

Efficacy and safety of isatuximab plus bortezomib, lenalidomide, and dexamethasone in patients with newly diagnosed multiple myeloma ineligible/with no immediate intent for autologous stem cell transplantation.

Patients with newly diagnosed multiple myeloma (NDMM) ineligible for autologous stem cell transplantation (ASCT) have lower survival rates and may benefit from frontline regimens that include novel agents. This Phase 1b study (NCT02513186) evaluated preliminary efficacy, safety, and pharmacokinetics (PK) of isatuximab, an anti-CD38 monoclonal antibody, combined with bortezomib-lenalidomide-dexamethasone (Isa-VRd) in patients with NDMM ineligible for/with no intent for immediate ASCT. Overall, 73 patients received four 6-week induction cycles of Isa-VRd, then maintenance with Isa-Rd in 4-week cycles. In the efficacy population (n = 71), the overall response rate was 98.6%, with 56.3% achieving a complete response or better (sCR/CR), and 36/71 (50.7%) patients reaching minimal residual disease negativity (10-5 sensitivity). Grade ≥3 treatment-emergent adverse events (TEAEs) occurred in 79.5% (58/73) of patients but TEAEs leading to permanent study treatment discontinuation were reported in 14 (19.2%) patients. Isatuximab PK parameters were within the previously reported range, suggesting that VRd does not alter the PK of isatuximab. These data support additional studies of isatuximab in NDMM, such as the Phase 3 IMROZ study (Isa-VRd vs VRd).

New Strategies for the Treatment of Older Myeloma Patients.

Multiple myeloma (MM) mostly affects older patients, who represent a highly heterogeneous population. In the last few years, the introduction of novel agents led to a significant improvement in the outcome of MM patients. Nonetheless, this positive trend is less likely to occur in all older patients due to comorbidities/disabilities and major susceptibility to toxic events. Furthermore, older patients with major comorbidities are usually excluded or underrepresented in most registrational clinical trials. In this context, physicians have called for greater caution in the management of the disease. Several scores allow for the identification of frail and unfit patients and establish the possibility of tailoring therapy, reducing toxicity. This review explores the available tools for the assessment of frailty and what has been done to improve the discriminative power of the available scores. Thereafter, it describes the main therapeutic strategies for the management of transplant-ineligible (NTE) newly diagnosed (ND) MM patients and relapsed/refractory (RR) MM patients, in order to better guide physicians in choosing treatment options and to suggest possible strategies for more frail patients.

Ixazomib Versus Placebo as Postinduction Maintenance Therapy in Newly Diagnosed Multiple Myeloma Patients: An Analysis by Age and Frailty Status of the TOURMALINE-MM4 Study.

BACKGROUND: The TOURMALINE-MM4 trial demonstrated a significant and clinically meaningful progression-free survival (PFS) benefit with ixazomib versus placebo as postinduction maintenance in nontransplant, newly-diagnosed multiple myeloma patients, with a manageable and well-tolerated toxicity profile. MATERIALS AND METHODS: In this subgroup analysis, efficacy and safety were assessed by age (< 65, 65-74, and ≥ 75 years) and frailty status (fit, intermediate-fit, and frail). RESULTS: In this analysis, PFS benefit with ixazomib versus placebo was seen across age subgroups, including patients aged < 65 years (hazard ratio [HR], 0.576; 95% confidence interval [CI], 0.299-1.108; P = .095), 65-74 years (HR, 0.615; 95% CI, 0.467-0.810; P < .001), and ≥ 75 years (HR, 0.740; 95% CI, 0.537-1.019; P = .064). PFS benefit was also seen across frailty subgroups, including fit (HR, 0.530; 95% CI, 0.387-0.727; P < .001), intermediate-fit (HR, 0.746; 95% CI, 0.526-1.058; P = .098), and frail (HR, 0.733; 95% CI, 0.481-1.117; P = .147) patients. With ixazomib versus placebo, rates of grade ≥ 3 treatment-emergent adverse events (TEAEs; 28-44% vs. 10-36%), serious TEAEs (15-29% vs. 3-29%), and discontinuation due to TEAEs (7-19% vs. 5-11%) were higher or similar across age and frailty subgroups, and generally somewhat higher in older age groups and intermediate-fit/frail patients in both arms. Treatment with ixazomib versus placebo did not adversely affect patient-reported quality-of-life scores across age and frailty status subgroups. CONCLUSION: Ixazomib is a feasible and effective maintenance option for prolonging PFS across this heterogeneous patient population.

Patients with Very High Risk of Cardiovascular Adverse Events during Carfilzomib Therapy: Prevention and Management of Events in a Single Center Experience.

Carfilzomib (CFZ) improves the prognosis of multiple myeloma (MM) patients but has shown cardiovascular toxicity. The risk stratification of cardiovascular adverse events (CVAEs) now seems well established, while little is known about the course and management of patients with a high-cardiovascular-risk profile or experiencing CVAEs during therapy. Therefore, we aimed to describe our experience in decision making to support health professionals in selecting the best management strategies to prevent and treat CVAEs. A total of 194 patients with indication to CFZ underwent baseline evaluation of CVAEs risk and were prospectively followed. We propose a novel approach, which includes advanced cardiac imaging testing for patients at high baseline CV risk to rule out clinical conditions that could contraindicate starting CFZ. After baseline evaluation, 19 (9.8%) patients were found at high risk of CVAEs: 13 (6.7%) patients underwent advanced cardiac testing and 3 (1.5%) could not receive CFZ due to CV contraindications. A total of 178 (91.7%) patients started CFZ: 82 (46%) experienced arterial-hypertension-related events and 37 (20.8%) major CVAEs; 19 (10.7%) patients had to discontinue or modify the CFZ dosing regimen. Along with baseline risk stratification, subsequent cardiovascular clinical events and diagnostic follow-up both provided critical data to help identify conditions that could contraindicate the anticancer therapy.

Carfilzomib-Based Regimen and Cardiotoxicity in Multiple Myeloma: Incidence of Cardiovascular Events and Organ Damage in Carfilzomib-Dexamethasone versus Carfilzomib-Lenalidomide-Dexamethasone. A Real-Life Prospective Study.

Carfilzomib-mediated cardiotoxicity in multiple myeloma (MM) is a well-established adverse effect, however limited data are available on the comparison of cardiovascular complications in patients treated with Carfilzomib-dexamethasone (target dose of K 56 mg/m2) versus Carfilzomib-lenalidomide-dexamethasone (target dose of K 27 mg/m2) beyond controlled trials. A total of 109 patients were enrolled, 47 (43%) received Kd and 62 (57%) KRd. They then underwent a baseline and follow-up evaluation including trans-thoracic echocardiography and arterial stiffness estimation. All types of cardiovascular and hypertensive events occurred more frequently in the Kd group compared with the KRd (59% vs. 40% and 55% vs. 35.5% patients, respectively, p ≤ 0.05), with higher incidence of hypertensive. The time of onset of any type of CVAE, and of major and hypertensive events was shorter in the Kd regimen (p ≤ 0.05). At follow-up, Kd patients more frequently developed signs of cardiac (decline of global longitudinal strain) and vascular organ damage (rise of pulse wave velocity), as compared with KRd. Despite the older age, longer history of MM and longer period of pre-treatment of Kd patients, these factors did not increase the probability of incidence for all types of cardiovascular events at multivariate analysis (p > 0.05). In conclusion, the Kd regimen showed greater cardiovascular toxicity and earlier onset of events with respect to KRd. Thus, a closer and thorough follow-up should be considered.

The prevalence and outcomes of frail older adults in clinical trials in multiple myeloma: A systematic review.

Multiple myeloma (MM) is an incurable blood cancer that primarily affects older adults. Several frailty tools have been developed to address the heterogeneity of aging in this population. Uptake of these measures has been variable, leading to a gap in knowledge regarding the proportion of enrolled trial participants considered frail and uncertainty in the treatment-related effects and outcomes among this high-risk population. We performed a systematic review of therapeutic interventional MM clinical trials reporting on frailty. We included 43 clinical trials (24 randomized controlled trials and 19 non-randomized trials) which met eligibility criteria. Frailty was increasingly incorporated in studies in more recent years with 41.9% of included studies being reported in the last two years. Commonly used frailty tools included the International Myeloma Working Group (IMWG) frailty index (41.8%), and the simplified frailty score (39.5%). Frailty status was categorized with 3 levels as (frail, intermediate fit, or fit) in 51.2% of the studies and dichotomized (frail, non-frail) in 18.6% of studies. Frailty prevalence greatly varied across trials ranging from 17.2% to 73.6% of the cohort. Of the included studies, 72.0% conducted subgroup analysis (planned or post-hoc) based on frailty status. Most studies demonstrated a consistent benefit of MM interventions among the frail and non-frail populations, however in general, frail patients had worse outcomes compared to the fit. Although frailty is increasingly being incorporated in MM clinical trials, due to the variation in both the definition and categorization of frailty, there remains heterogeneity in the prevalence of frailty and its potential associated impact on outcomes.

Evaluation of isatuximab in patients with soft-tissue plasmacytomas: An analysis from ICARIA-MM and IKEMA.

The Phase 3 ICARIA-MM (NCT02990338) and IKEMA (NCT03275285) studies demonstrated that isatuximab (Isa) plus pomalidomide (P) and dexamethasone (d; Isa-Pd) or carfilzomib (K) and d (Isa-Kd) improved progression-free survival (PFS) versus Pd or Kd in patients with relapsed and/or refractory multiple myeloma. In this post hoc analysis of patients with soft-tissue plasmacytomas, we evaluated Isa-Pd/Isa-Kd efficacy using central radiology and central laboratory assessments. Given the low incidence of soft-tissue plasmacytomas (7.8 %, ICARIA-MM; 6.3 %, IKEMA), efficacy data were pooled across the two studies. PFS (HR, 0.47; 95 % CI, 0.21-1.08), overall response rate (50.0 % vs 17.7 %), and very good partial response or better rate (26.9 % vs 11.8 %) were improved with Isa-Pd/Isa-Kd versus Pd/Kd, with consistent improvements within individual studies. Patients with soft-tissue plasmacytomas who received Isa-Pd/Isa-Kd had similar median PFS compared with those without soft-tissue plasmacytomas and received Pd/Kd. Safety is reported individually per study. Longer median treatment duration and more Grade ≥ 3 treatment-emergent adverse events occurred in the Isa versus control arms in ICARIA-MM (36.9 vs 8.4 weeks; 85.7 % vs 70.0 %) and IKEMA (41.9 vs 29.9 weeks; 100.0 % vs 57.1 %); however, Isa did not increase the percentage of patients with fatal events or drug discontinuation. Isa-Pd or Isa-Kd is a potential new treatment option and partially overcomes the poor prognosis associated with soft-tissue plasmacytomas in relapsed and/or refractory multiple myeloma.

Survival Risk Scores for Real-Life Relapsed/Refractory Multiple Myeloma Patients Receiving Elotuzumab or Carfilzomib In Combination With Lenalidomide and Dexamethasone as Salvage Therapy: Analysis of 919 Cases Outside Clinical Trials.

The present study aimed to develop two survival risk scores (RS) for overall survival (OS, SRS KRd/EloRd ) and progression-free survival (PFS, PRS KRd/EloRd ) in 919 relapsed/refractory multiple myeloma (RRMM) patients who received carfilzomib, lenalidomide, and dexamethasone (KRd)/elotuzumab, lenalidomide, and dexamethasone (EloRd). The median OS was 35.4 months, with no significant difference between the KRd arm versus the EloRd arm. In the multivariate analysis, advanced ISS (HR = 1.31; P = 0.025), interval diagnosis-therapy (HR = 1.46; P = 0.001), number of previous lines of therapies (HR = 1.96; P < 0.0001), older age (HR = 1.72; P < 0.0001), and prior lenalidomide exposure (HR = 1.30; P = 0.026) remained independently associated with death. The median PFS was 20.3 months, with no difference between the two strategies. The multivariate model identified a significant progression/death risk increase for ISS III (HR = 1.37; P = 0.002), >3 previous lines of therapies (HR = 1.67; P < 0.0001), older age (HR = 1.64; P < 0.0001), and prior lenalidomide exposure (HR = 1.35; P = 0.003). Three risk SRS KRd/EloRd categories were generated: low-risk (134 cases, 16.5%), intermediate-risk (467 cases, 57.3%), and high-risk categories (213 cases, 26.2%). The 1- and 2-year OS probability rates were 92.3% and 83.8% for the low-risk (HR = 1, reference category), 81.1% and 60.6% (HR = 2.73; P < 0.0001) for the intermediate-risk, and 65.5% and 42.5% (HR = 4.91; P < 0.0001) for the high-risk groups, respectively. Notably, unlike the low-risk group, which did not cross the median timeline, the OS median values were 36.6 and 18.6 months for the intermediate- and high-risk cases, respectively. Similarly, three PRS KRd/EloRd risk categories were engendered. Based on such grouping, 338 (41.5%) cases were allocated in the low-, 248 (30.5%) in the intermediate-, and 228 (28.0%) in the high-risk groups. The 1- and 2-year PFS probability rates were 71.4% and 54.5% for the low-risk (HR = 1, reference category), 68.9% and 43.7% (HR = 1.95; P < 0.0001) for the intermediate-risk, and 48.0% and 27.1% (HR = 3.73; P < 0.0001) for the high-risk groups, respectively. The PFS median values were 29.0, 21.0, and 11.7 months for the low-, intermediate-, and high-risk cases. This analysis showed 2.7- and 4.9-fold increased risk of death for the intermediate- and high-risk cases treated with KRd/EloRd as salvage therapy. The combined progression/death risks of the two categories were increased 1.3- and 2.2-fold compared to the low-risk group. In conclusion, SRS KRd/EloRd and PRS KRd/EloRd may represent accessible and globally applicable models in daily clinical practice and ultimately represent a prognostic tool for RRMM patients who received KRd or EloRd.

Elotuzumab plus lenalidomide and dexamethasone in relapsed/refractory multiple myeloma: Extended 3-year follow-up of a multicenter, retrospective clinical experience with 319 cases outside of controlled clinical trials.

The combination of elotuzumab, lenalidomide, and dexamethasone (EloRd) enhanced the clinical benefit over Rd with a manageable toxicity profile in the ELOQUENT-2 trial, leading to its approval in relapsed/refractory multiple myeloma (RRMM). The present study is a 3-year follow-up update of a previously published Italian real-life RRMM cohort of patients treated with EloRd. This revised analysis entered 319 RRMM patients accrued in 41 Italian centers. After a median follow-up of 36 months (range 6-55), 236 patients experienced disease progression or died. Median progression-free survival (PFS) and overall survival (OS) were 18.4 and 34 months, respectively. The updated multivariate analyses showed a significant reduction of PFS and OS benefit magnitude only in cases with International Staging System stage III. Major adverse events included grade 3/4 neutropenia (18.5%), anemia (15.4%), lymphocytopenia (12.5%), and thrombocytopenia (10.7%), while infection rates and pneumonia were 33.9% and 18.9%, respectively. No new safety signals with longer follow-up have been observed. Of 319 patients, 245 (76.7%) reached at least a partial remission. A significantly lower response rate was found in patients previously exposed to lenalidomide. In conclusion, our study confirms that EloRd is a safe and effective regimen for RRMM patients, maintaining benefits across multiple unfavorable subgroups.

Safety of Rapid Daratumumab Infusion: A Retrospective, Multicenter, Real-Life Analysis on 134 Patients With Multiple Myeloma.

Background: The anti-CD38 monoclonal antibody daratumumab is the backbone of most anti-multiple myeloma (MM) regimens. To mitigate the risk of infusion-related reactions (IRRs), intravenous daratumumab administration requires 7 hours for the first infusion and 3.5-4 hours thereafter, thus making daratumumab-containing regimens burdensome for patients and health care resources. Preliminary data suggest that a rapid (90-minute) infusion of daratumumab is safe and does not increase IRRs. The rapid schedule was adopted by our centers since 2019. Methods: We conducted an observational multi-center, real-life study to assess the safety of rapid daratumumab infusion protocol from the third administration in relapsed MM patients receiving daratumumab alone or in combination with lenalidomide-dexamethasone or bortezomib-dexamethasone. The primary endpoint was the safety of the rapid infusion protocol, particularly in terms of IRRs. Results: A total of 134 MM patients were enrolled. IRRs occurred in 7 (5%) patients and were mostly mild (6/7 of grade 1-2), with only 1 patient experiencing a grade 3 IRR. Due to the IRRs, 5 (3.7%) patients discontinued the rapid infusions and resumed daratumumab at the standard infusion rate, while 1 patient permanently discontinued daratumumab. In 4/7 patients (57%), IRRs occurred while resuming rapid daratumumab infusions after a temporary interruption (2-4 months). No other adverse event was considered related to the rapid infusion protocol. Conclusions: Our findings confirmed the safety of rapid daratumumab infusions starting from the third administration. In case of prolonged daratumumab interruption, it is advisable to resume infusions at the standard rate (3.5 hours) before switching to the rapid infusion.