Preemptive Approach to Plerixafor Use Is Optimal in Patients With Relapsed/Refractory Germ Cell Tumors Undergoing Peripheral Blood Hematopoietic Stem Cell Collection: Effect on Collection Days, Yields, and Cost.

Evidence describing the use of plerixafor in the off-label population of relapsed/refractory germ cell tumors (GCT) is limited. We aim to describe the effect of rescue versus preemptive plerixafor use on apheresis collection days, collection yields, and cost. We retrospectively collected data on 77 consecutive patients (at least 15 years of age) with GCT who underwent peripheral blood stem cell (PBSC) collection for autologous stem cell transplant between January 1, 2020 and May 1, 2022. Depending on insurance approval, plerixafor was given either as "rescue" (after a first apheresis collection of < 5 × 106 CD34+ cells/kg) or as "preemptive" on Day 4 of granulocyte-colony stimulating factor (G-CSF) prior to the first apheresis collection, if the Day 4 peripheral blood CD34+ count was < 40 cells/µL. A total of 66% of patients who received preemptive plerixafor completed collection in 1 day, similar to good mobilizers who only needed G-CSF (71%, p = 0.366). In contrast, all poor mobilizers in the rescue group required at least 2 days of collection and had lower CD34+ cell yields than the preemptive group (7.15 vs. 9.81 × 106/kg, p = 0.0055). A cost analysis revealed that preemptive plerixafor may save approximately $7000 per patient compared with a rescue approach. Preemptive plerixafor in GCT patients undergoing PBSC collection allows relatively poor mobilizers to collect in fewer days and with lower overall cost. Fewer apheresis procedures result in less risk to the patient, increased patient satisfaction, and the ability to schedule more patients within the constraints of staffing.

Impact of plerixafor (mozobil) on hospital efficiency: A single center experience.

Plerixafor (Mozobil) in combination with granulocyte colony-stimulating factor (G-CSF) has shown to increase mobilization of peripheral blood stem cells (PBSC) as compared to G-CSF alone in patients undergoing autologous stem cell transplantation (ASCT). However, up to 25% of patients treated with G-CSF alone still fail mobilization. Adding plerixafor to poor mobilizers allows to rescue these patients from mobilization failure and to reduce the number of apheresis sessions. The goal of this retrospective study was to capture the impact of plerixafor on treatment outcome and on apheresis department efficiency. The latter was measured in terms of time-slots lost, that is, the number of apheresis sessions scheduled but not carried out due to poor mobilization, and the number of elective apheresis sessions performed for patients undergoing extracorporeal photopheresis (ECP). Hospital records of patients treated before and after introduction of plerixafor were collected and analyzed. With plerixafor, the mobilization failure rate dropped from 12% to 4% and the mean number of time-slots lost per patient dropped from 1.39 to 0.89. Additional drug costs due to plerixafor were partially balanced by a reduction in apheresis sessions, resulting in an additional cost of 759€ per ASCT candidate. More importantly, with the use of plerixafor, the availability of time-slots turned from erratic to predictable such that freed capacity could be dedicated to other apheresis procedures. As a result, the number of ECP sessions increased from 0 in 2005 to 685 sessions in 2014.

UK consensus statement on the use of plerixafor to facilitate autologous peripheral blood stem cell collection to support high-dose chemoradiotherapy for patients with malignancy.

Plerixafor is a CXC chemokine receptor (CXCR4) antagonist that mobilizes stem cells in the peripheral blood. It is indicated (in combination with granulocyte-colony stimulating factor [G-CSF]) to enhance the harvest of adequate quantities of cluster differentiation (CD) 34+ cells for autologous transplantation in patients with lymphoma or multiple myeloma whose cells mobilize poorly. Strategies for use include delayed re-mobilization after a failed mobilization attempt with G-CSF, and rescue or pre-emptive mobilization in patients in whom mobilization with G-CSF is likely to fail. Pre-emptive use has the advantage that it avoids the need to re-schedule the transplant procedure, with its attendant inconvenience, quality-of-life issues for the patient and cost of additional admissions to the transplant unit. UK experience from 2 major centers suggests that pre-emptive plerixafor is associated with an incremental drug cost of less than £2000 when averaged over all patients undergoing peripheral blood stem cell (PBSC) transplant. A CD34+ cell count of <15 µl-1 at the time of recovery after chemomobilization or after four days of G-CSF treatment, or an apheresis yield of <1 × 106 CD34+ cells/kg on the first day of apheresis, could be used to predict the need for pre-emptive plerixafor.

Evaluating the use of plerixafor in stem cell mobilisation - an economic analysis of the PHANTASTIC trial.

Plerixafor is an effective haematopoietic stem cell mobilising agent in candidates for autologous transplantation, including patients with myeloma and lymphoma. Here we compare 98 plerixafor recipients in the PHANTASTIC trial with 151 historic controls mobilised by conventional chemotherapy (each with granulocyte colony-stimulating factor, G-CSF). Seventy (71.4%) plerixafor-mobilised patients achieved the composite primary endpoint of ≥4 × 10(6) CD34+ cells kg(-1) in ≤2 aphereses and no clinically significant neutropenia, compared to 48 (31.8%) historic controls (P < 0.001), and this significant advantage was maintained in scenario analyses testing components of this composite endpoint. A patient-level cost analysis was undertaken for 249 patients, which included the cost of remobilising patients where initial mobilisation had failed. Combined mean treatment cost for plerixafor mobilised patients was £12,679 compared with £11,694 for historical controls. However, plerixafor produces an average saving of £3,828 per lymphoma patient but average cost increase by £5,245 per myeloma patient. The present data demonstrate cost-effectiveness for plerixafor as a first line mobilisation agent, certainly for lymphoma patients, where substantial resource savings and achievement of the primary endpoint are likely. J. Clin. Apheresis 31:434-442, 2016. © 2015 Wiley Periodicals, Inc.

Hematopoietic progenitor cell mobilization with "just-in-time" plerixafor approach is a cost-effective alternative to routine plerixafor use.

BACKGROUND AIMS: Hematopoietic cell mobilization with granulocyte-colony stimulating factor (G-CSF) and plerixafor results in superior CD34+ cell yield compared with G-CSF alone in patients with myeloma and lymphoma. However, plerixafor-based approaches may be associated with high costs. Several institutions use a "just-in-time" plerixafor approach, in which plerixafor is only administered to patients likely to fail mobilization with G-CSF alone. Whether such an approach is cost-effective is unknown. METHODS: We evaluated 136 patients with myeloma or lymphoma who underwent mobilization with 2 approaches of plerixafor utilization. Between January 2010 and October 2012, 76 patients uniformly received mobilization with G-CSF and plerixafor. Between November 2012 and June 2014, 60 patients were mobilized with plerixafor administered only to those patients likely to fail mobilization with G-CSF alone. RESULTS: The routine plerixafor group had a higher median peak peripheral blood CD34+ cell count (62 versus 29 cells/µL, P < 0.001) and a higher median day 1 CD34+ yield (2.9 × 10(6) CD34+ cells/kg versus 2.1 × 10(6) CD34+ cells/kg, P = 0.001). The median total CD34+ collection was higher with routine plerixafor use (5.8 × 10(6) CD34+ cells/kg versus 4.5 × 10(6) CD34+ cells/kg, P = 0.007). In the "just-in-time" group, 40% (n = 24) completed adequate collection without plerixafor. There was no difference in mobilization failure rates. The mean plerixafor doses used was lower with "just-in-time" approach (1.3 versus 2.1, P = 0.0002). The mean estimated cost in the routine plerixafor group was higher (USD 27,513 versus USD 23,597, P = 0.01). DISCUSSION: Our analysis demonstrates that mobilization with a just-in-time plerixafor approach is a safe, effective, and cost-efficient strategy for HPC collection.

A nationwide survey of the use of plerixafor in patients with lymphoid malignancies who mobilize poorly demonstrates the predominant use of the "on-demand" scheme of administration at French autologous hematopoietic stem cell transplant programs.

BACKGROUND: High-dose chemotherapy supported with autologous stem cell transplantation is a standard therapeutic option for a subset of patients with lymphoid malignancies. Cell procurement is nowadays done almost exclusively through cytapheresis, after mobilization of hematopoietic stem and progenitor cells (HSPCs) from the marrow to peripheral blood (PB). The egress of HSPCs out of hematopoietic niches occurs in various physiologic or nonhomeostatic situations; pharmacologic approaches include the administration of acutely myelosuppressive agents or hematopoietic growth factors such as recombinant human granulocyte-colony-stimulating factor (rHuG-CSF). The introduction of plerixafor, a first-of-its-class molecule that reversibly inhibits the interaction between the chemokine CXCL-12 (also known as SDF-1) and its receptor CXCR-4, has offered new opportunities for the so-called "poor mobilizers" who achieve insufficient mobilization and/or collection with conventional approaches. STUDY DESIGN AND METHODS: Because of the lack of consensus on a definition for poor mobilizers and the relatively high cost of plerixafor, French competent authorities have mandated a postmarketing survey on its use in routine practice. RESULTS AND CONCLUSION: We report here the results of this nationwide survey that confirms the clinical efficacy of plerixafor, even in the subset of patients who barely increased PB CD34+ cell count in response to rHuG-CSF-containing mobilization regimen. Furthermore, analysis of this registry showed that despite heterogeneity in medical practices, the early-"on-demand" or "preemptive"-introduction of plerixafor was widely used and did not result in an excess of prescriptions, beyond its expected use at the time when marketing authorization was granted.

Plerixafor on-demand combined with chemotherapy and granulocyte colony-stimulating factor: significant improvement in peripheral blood stem cells mobilization and harvest with no increase in costs.

To date, no prospective study on Plerixafor 'on-demand' in combination with chemotherapy and granulocyte colony-stimulating factor (G-CSF) has been reported. We present an interim analysis of the first prospective study in which Plerixafor was administered on-demand in patients affected by multiple myeloma and lymphoma who received high dose cyclophosphamide or DHAP (dexamethasone, cytarabine, cisplatin) plus G-CSF to mobilize peripheral blood stem cells (PBSC). One hundred and two patients were evaluable for response. A cohort of 240 patients receiving the same mobilizing chemotherapy was retrospectively studied. Failure to mobilize CD34(+) cells in peripheral blood was reduced by 'on-demand' strategy compared to conventional mobilization; from 13·0 to 3·0% (P = 0·004). Failure to harvest CD34(+) cells 2 × 10(6) /kg decreased from 20·9 to 4·0% (P = 0·0001). The on-demand Plerixafor strategy also resulted in a lower rate of mobilization failure (P = 0·03) and harvest failure (P = 0·0008) when compared to a 'bias-adjusted set of controls'. Evaluation of economic costs of the two strategies showed that the overall cost of the two treatments were comparable when salvage mobilizations were taken into account. When in combination with cyclophosphamide or DHAP plus G-CSF, the 'on-demand' use of Plerixafor showed, in comparison to conventionally treated patients, a significant improvement in mobilization of PBSC with no increase in overall cost.

GCSF with or without chemotherapy compared to Plerixafor with GCSF as salvage mobilization regimen in patients with multiple myeloma and lymphoma: collection effectiveness and cost effectiveness analysis.

INTRODUCTION: Plerixafor is a novel mobilizing agent of peripheral blood stem cells (PBSCs) in lymphoma and multiple myeloma (MM) patients whose cells mobilize poorly. Due to the substantial cost associated with its use, we aimed to compare the effectiveness and cost effectiveness of Plerixafor + GCSF (PG) versus GCSF ± Chemotherapy (GC) as salvage mobilization regimens. METHODS: The charts of consecutive lymphoma and MM patients who had undergone at least one previous attempt of PBSCs mobilization that failed or resulted in an insufficient cell dose for transplant between 2007 and 2010 were retrospectively reviewed. Patients identified received salvage mobilization with GC (prior to 2009) or PG after Plerixafor's FDA approval. Data collected included demographics, medical histories, apheresis yields and transplant outcome. The cost effectiveness analysis was from the perspective of the Jordanian Ministry of Health. The incremental cost effectiveness ratio (ICER) was calculated by dividing the difference in cost by the difference in effectiveness for the two regimens. RESULTS: Five patients received GC and twelve received PG. A minimum CD34+ cell dose of 2 × 10(6) cells/kg was collected from 8 patients (67%) in the PG group compared to 3 (60%) in the GC group (p=0.79). The average costs were US$8570 and US$25,700 for the GC group and the PG group, respectively. The ICER was US$244,714 per successful stem cell collection. CONCLUSION: Salvage Plerixafor use showed a non-significant improvement in PBSCs collection with a significant increase in cost. Prospective comparative effectiveness studies are warranted to inform the optimal salvage mobilization regimen. To our knowledge, this is the first study from the Middle East to describe the effectiveness and cost effectiveness of Plerixafor.

Cost-effectiveness analysis of a risk-adapted algorithm of plerixafor use for autologous peripheral blood stem cell mobilization.

Historically, up to 30% of patients were unable to collect adequate numbers of peripheral blood stem cells (PBSCs) for autologous stem cell transplantation (ASCT). Plerixafor in combination with granulocyte colony-stimulating factor (G-CSF) has shown superior results in mobilizing peripheral blood (PB) CD34+ cells in comparison to G-CSF alone, but its high cost limits general use. We developed and evaluated risk-adapted algorithms for optimal utilization of plerixafor. In plerixafor-1, PBSC mobilization was commenced with G-CSF alone, and if PB CD34 on day 4 or day 5 was <10/µL, plerixafor was administered in the evening, and apheresis commenced the next day. In addition, if on any day, the daily yield was <0.5 × 10(6) CD34/kg, plerixafor was added. Subsequently, the algorithm was revised (plerixafor-2) with lower thresholds. If day-4 PB CD34 <10/µL for single or <20/µL for multiple transplantations, or day-1 yield was <1.5 × 10(6) CD34/kg, or any subsequent daily yield was <0.5 × 10(6) CD34/kg, plerixafor was added. Three time periods were analyzed for results and associated costs: January to December 2008 (baseline cohort; 319 mobilization attempts in 278 patients); February to November 2009 (plerixafor-1; 221 mobilization attempts in 216 patients); and December 2009 to June 2010 (plerixafor-2; 100 mobilization attempts in 98 patients). Plerixafor-2 shows a significant improvement in PB CD34 collection, increased number of patients reaching minimum and optimal goals, fewer days of apheresis, and fewer days of mobilization/collection, albeit at increased costs. In conclusion, although the earlier identification of ineffective PBSC mobilization and initiation of plerixafor (plerixafor-2) increases the per-patient costs of PBSC mobilization, failure rates, days of apheresis, and total days of mobilization/collection are lower.

A retrospective study of autologous stem cell mobilization to guide an immediate salvage protocol using plerixafor for patients who mobilize stem cells poorly.

The addition of plerixafor to G-CSF decreases the risk of failed stem cell collection, but at considerable extra cost. Using a logistic regression model based on 354 autologous mobilizations, we have identified a local minimum peripheral blood CD34 count at which the probability of a successful collection is 50%. This seems an appropriate CD34 count at which to add immediate salvage plerixafor.

Cost-effectiveness of hematopoietic stem cell mobilization strategies including plerixafor in multiple myeloma and lymphoma patients.

Peripheral blood stem cells (PBSCs) are preferred source of hematopoietic stem cells for autologous transplantation. Mobilization of PBSCs using chemotherapy and/or granulocyte colony-stimulating factor (G-CSF) however fails in around 20%. Combining G-CSF with plerixafor increases the mobilizations success. We compared cost-effectiveness of following schemes: the use of plerixafor "on demand" (POD) during the first mobilization in all patients with inadequate response, the remobilization with plerixafor following failure of the first standard mobilization (SSP), and the standard (re)mobilization scheme without plerixafor (SSNP). Decision tree models populated with data from a first-of-a-kind patient registry in six Czech centers (n = 93) were built to compare clinical benefits and direct costs from the payer's perspective. The success rates and costs for POD, SSP and SSNP mobilizations were; 94.9%, $7,197; 94.7%, $8,049; 84.7%, $5,991, respectively. The direct cost per successfully treated patient was $7,586, $8,501, and $7,077, respectively. The cost of re-mobilization of a poor mobilizer was $5,808 with G-CSF only and $16,755 if plerixafor was added. The total cost of plerixafor "on-demand" in the sub-cohort of poor mobilizers was $17,120. Generally, plerixafor improves the mobilization success by 10% and allows an additional patient to be successfully mobilized for incremental $11,803. Plerixafor is better and cheaper if used "on demand" than within a subsequent remobilization.

Peripheral blood stem cell mobilization in multiple myeloma patients treat in the novel therapy-era with plerixafor and G-CSF has superior efficacy but significantly higher costs compared to mobilization with low-dose cyclophosphamide and G-CSF.

Studies comparing the efficacy and cost of peripheral blood stem and progenitor cells mobilization with low-dose cyclophosphamide (LD-CY) and granulocyte-colony stimulating factor (G-CSF) against plerixafor and G-CSF, in multiple myeloma (MM) patients treated in the novel therapy-era are not available. Herein, we report mobilization outcomes of 107 patients who underwent transplantation within 1-year of starting induction chemotherapy with novel agents. Patients undergoing mobilization with LD-CY (1.5 gm/m(2)) and G-CSF (n = 74) were compared against patients receiving plerixafor and G-CSF (n = 33). Compared to plerixafor, LD-CY was associated with a significantly lower median peak peripheral blood CD34+ cell count (68/µL vs. 36/µL, P = 0.048), and lower CD34+ cell yield on day 1 of collection (6.9 × 10(6)/kg vs. 2.4 × 10(6)/kg, P = 0.001). Six patients (8.1%) in the LD-CY group experienced mobilization failure, compared to none in the plerixafor group. The total CD34+ cell yield was significantly higher in the plerixafor group (median 11.6 × 10(6)/kg vs. 7 × 10(6)/kg; P-value = 0.001). Mobilization with LD-CY was associated with increased (albeit statistically non-significant) episodes of febrile neutropenia (5.4% vs. 0%; P = 0.24), higher use of intravenous antibiotics (6.7% vs. 3%; P = 0.45), and need for hospitalizations (9.4% vs. 3%; P = 0.24). The average total cost of mobilization in the plerixafor group was significantly higher compared to the LD-CY group ($28,980 vs. $19,626.5 P-value < 0.0001). In conclusion, in MM plerixafor-based mobilization has superior efficacy, but significantly higher mobilization costs compared to LD-CY mobilization. Our data caution against the use of LD-CY in MM patients for mobilization, especially after induction with lenalidomide-containing regimens.

Pegfilgrastim- versus filgrastim-based autologous hematopoietic stem cell mobilization in the setting of preemptive use of plerixafor: efficacy and cost analysis.

BACKGROUND: Plerixafor enhances the ability of filgrastim (FIL) to mobilize CD34+ cells but adds cost to the mobilization. We hypothesized that replacing weight-based FIL with flat-dose pegfilgrastim (PEG) in a validated cost-based mobilization algorithm for patient-adapted use of plerixafor would add convenience without increased cost. STUDY DESIGN AND METHODS: A single-center retrospective analysis compared two consecutive cohorts undergoing FIL or PEG mobilization before autologous hematopoietic stem cell transplantation for multiple myeloma or lymphoma. FIL dose was 10 µg/kg/day continuing until completion of collection and a 12-mg flat dose of PEG. Peripheral blood CD34+ cells (PB-CD34+) enumeration was performed on the fourth day after initiation of growth factor. Subjects surpassing a certain target-specific threshold of PB-CD34+ started apheresis immediately while subjects with lower PB-CD34+ received plerixafor with apheresis starting on the fifth day. RESULTS: Overall 68 of 74 in the FIL group and 52 of 57 patients in the PEG group met the mobilization target. Only one patient in each cohort required remobilization. Median PB-CD34+ on Day 4 was significantly higher in patients in the PEG group (18.1×10(6) vs. 28.7×10(6)cells/L, p=0.01). Consequently, patients in the PEG group were less likely to require administration of plerixafor (67.5% vs. 45.6%, p=0.01). Cohorts had near identical mean number of apheresis sessions and comparable CD34+ yield. The estimated cost associated with growth factor was higher in patients in the PEG group, but it was counterbalanced by lower cost associated with use of plerixafor. CONCLUSION: Single administration of 12 mg of PEG is associated with better CD34+ mobilization than FIL allowing for effective, convenient mobilization with less frequent use of plerixafor.

Retrospective comparison of filgrastim plus plerixafor to other regimens for remobilization after primary mobilization failure: clinical and economic outcomes.

We performed a retrospective analysis to evaluate clinical and economic outcomes in patients receiving remobilization therapy after primary mobilization failure. Our primary endpoint was to compare filgrastim plus plerixafor to other regimens in their ability to collect a target cell dose of at least 2 million CD34+ cells/kg (cumulative). Of 96 consecutive patients who failed their primary mobilization therapy and in whom a second mobilization was attempted, remobilization consisted of filgrastim plus plerixafor (n = 38), filgrastim with or without sargramostim (n = 43), or chemotherapy plus filgrastim (n = 15), 84% of filgrastim/plerixafor patients were able to collect at least 2 million CD34+ cells/kg from both mobilizations, compared to 60% of patients mobilized with chemotherapy/filgrastim and 79% of the filgrastim ± sargramostim patients (P = 0.17). However, when combined with cells collected from the first mobilization, 53% of filgrastim/plerixafor patients reached the target of 2 million CD34+ cells in one apheresis, compared to 20% of those receiving chemotherapy/filgrastim and 28% of those receiving filgrastim ± sargramostim (P = 0.02). Resource utilization, mobilization drug costs, clinical care costs, and total costs were significantly different. We conclude that while filgrastim/plerixafor is the most efficient remobilization strategy, those clinical benefits may not translate into lower cost, especially when multiple days of plerixafor administration are required.

Plerixafor in non-Hodgkin's lymphoma patients: a German analysis of time, effort and costs.

Mobilization and collection of peripheral blood stem cells is part of the standard treatment procedure for non-Hodgkin's lymphoma patients eligible for high-dose chemotherapy with autologous stem cell transplantation. Mobilization is usually achieved with chemotherapy and/or cytokines, but plerixafor might be added in case of poor mobilization. Due to the high cost several institutions have developed their own management pathway to optimize use of plerixafor. Such models are however rarely generalizable; in a multi-center, European, non-interventional study, evaluating the impact of plerixafor in poor mobilizers, country specific differences in patient treatment and cost structure were obvious. For German centers, there was a non-significant reduction in the number of apheresis sessions carried out and in apheresis costs. In contrast to other European countries the majority of German Plerixafor patients were very poor mobilizing patients with initial CD34+ cell count ≤ 10/µl (40/51). In this group the number of apheresis sessions decreased from 2.1 to 1.6 sessions per patient (p = 0.01) and costs decreased from €6246 to €4758 (p = 0.01). Our results show that preemptive plerixafor use has a strong effect in poor mobilizers with an initial CD34+ cell count ≤ 10 cells/µl.

A comparison of florfenicol and tulathromycine for the treatment of undifferentiated fever in feedlot calves.

The purpose of this study was to compare the relative cost-effectiveness of florfenicol with that of tulathromycin for treatment of undifferentiated fever (UF) in feedlot calves at ultra-high risk of developing UF that receive metaphylactic tulathromycin on arrival at the feedlot. Calves that received therapeutic florfenicol had lower overall mortality (P=.045) and bovine respiratory disease mortality (P=.050) compared with calves that received therapeutic tulathromycin, but no significant differences were detected in feedlot performance, carcass characteristics, or other animal health variables. There was a net advantage of Can$41.19/treated animal in the florfenicol group versus the tulathromycin group. This study demonstrates that it is more cost-effective to use florfenicol than tulathromycin for the initial treatment of UF in feedlot calves at ultra-high risk of developing UF that receive on-arrival metaphylactic tulathromycin.

Comparison of florfenicol and tulathromycin for the treatment of undifferentiated fever in Alberta feedlot calves.

The purpose of this study was to compare the efficacy and cost-effectiveness of florfenicol versus tulathromycin for initial treatment of undifferentiated fever in fall-placed steer calves that received metaphylactic tilmicosin on arrival at the feedlot. No significant differences (P > .10) were observed in undifferentiated fever relapses or the crude case fatality rate. Calves treated with florfenicol had a lower case fatality rate (P = .04) for bovine respiratory disease and Histophilus disease than did calves treated with tulathromycin. The net economic advantage of florfenicol over tulathromycin (Can$17.70/treated animal) was based on differences in costs for the trial drug and calf replacement owing to bovine respiratory disease and Histophilus disease case fatality.

Comparative efficacy of tilmicosin versus tulathromycin as a metaphylactic antimicrobial in feedlot calves at moderate risk for respiratory disease.

The purpose of this study was to compare the efficacy and cost-effectiveness of tilmicosin (MIC) versus tulathromycin (DRAX) as a metaphylactic antimicrobial in feedlot calves at moderate risk for bovine respiratory disease (BRD). Calves that received DRAX had significantly (P < or = .05) lower initial BRD treatment rates compared with calves that received MIC. However, there were no significant differences in the BRD relapse rate, railer rate, total mortality rate, BRD mortality rate, average daily gain, and dry matter conversion between the two groups. The economic advantage of the MIC group was Can$8.29/animal. Based on these results, while DRAX was more efficacious in reducing initial treatments for BRD in feedlot calves at moderate risk for disease, MIC was more cost-effective. The lower initial BRD treatment costs in the DRAX group did not offset the higher metaphylactic cost of DRAX.

Evaluation of the efficacy of tulathromycin as a metaphylactic antimicrobial in feedlot calves.

The purpose of this study was to determine the efficacy and cost-effectiveness of tulathromycin (DRAX) versus tilmicosin (MIC) or oxytetracycline (TET) as a metaphylactic antimicrobial in feedlot calves. Calves that received DRAX had significantly (P<.05) lower initial undifferentiated fever (UF) treatment and relapse rates; lower overall chronicity, overall mortality, and cause-specific mortality rates; higher average daily gains; and improved quality grades. However, calves that received DRAX also had poorer (P<.05) yield grades compared with calves that received MIC or TET and worse feed conversion compared with calves that received MIC. Net advantages in the DRAX group were 3.79CanDollars/animal and 16.96CanDollars/animal compared with the MIC and TET groups, respectively. Based on these results, DRAX is a more efficacious and cost-effective metaphylactic antimicrobial than MIC or TET in feedlot calves at ultra-high risk of developing UF. In addition, this study presents a comparison between two methods ("deads out" and "deads in") of calculating feedlot performance variables.