A 6-Month, Multicenter, Single-Arm Pilot Study to Evaluate the Efficacy and Safety of Generic Tacrolimus (TacroBell) After Primary Renal Transplantation

Evaluation of Clinical and Safety Outcomes Following Uncontrolled Tacrolimus Conversion in Adult Transplant Recipients

PURPOSE

To compare clinical and safety outcomes of transplant recipients converted between different tacrolimus formulations to those patients who remained on a single formulation in an outpatient environment.

METHODOLOGY

This was a single-center, retrospective cohort study at a large tertiary care medical center with an associated institutional outpatient pharmacy system. Adult transplant recipients with institutional pharmacy refill from August 1, 2009, to May 31, 2016, were assessed. Patients were allocated into four separate groups: Group (A) innovator tacrolimus (no conversion), Group (B) generic tacrolimus (no conversion), Group (C) single conversion (from innovator to single generic or from generic to innovator tacrolimus), and Group (D) multiple conversions. Index date was either the date of first tacrolimus product conversion (Groups C and D) or a pre-specified post-transplant time (Groups A and B).

RESULTS

Overall, 100 patients were included in the analysis, 63% were male, 62% were Caucasian, and 59% were renal transplant recipients. When compared between groups, linear trends in dose-normalized tacrolimus levels were similar in the pre-index date period (p=0.52) and in the post-index date period (p=0.08). When groups were compared individually, linear trends in dose-normalized tacrolimus levels were significantly different pre- versus post-index date for Group B (p=0.008). There were no differences in the linear trends of dose-normalized tacrolimus levels across the other groups (p>0.05 for all). After the index date, 43% of patients across all groups required tacrolimus dose modification with no differences by group (p=0.32). Allograft function and hospitalizations were similar across all groups.

CONCLUSIONS

Conversion between tacrolimus generic formulations has been suggested to be unsafe. This study demonstrates that switching tacrolimus products in post-transplant recipients does not alter dose-normalized tacrolimus trough concentrations, renal or hepatic function, pathology, or hospitalizations.

Comparison of the long-term efficacy and safety of generic Tacrobell with original tacrolimus (Prograf) in kidney transplant recipients

This study aimed to evaluate the long-term efficacy and safety of a generic tacrolimus (Tacrobell [TCB]) compared to the original tacrolimus (Prograf [PGF]) in kidney transplant recipients. In this retrospective observational study, we analyzed the data from 444 patients who took TCB as a first-line immunosuppressive drug and 245 patients who took PGF. The 5-year graft survival rate was 92% for patients in the PGF group and 97% for patients in the TCB group, respectively. Cox proportional hazards for a one-sided, noninferiority model showed noninferiority (upper confidence interval [CI] limit of the hazard ratio [HR]<1.2) for TCB compared to PGF (HR: 0.58; 95% CI: 0–1.14). The 5-year patient survival rate was 96% for patients in the PGF group and 97% for patients in the TCB group. Cox proportional hazards for a one-sided, noninferiority model showed noninferiority (upper confidence interval limit of the HR<2.0) for TCB compared to PGF (HR: 0.83; 95% CI: 0–1.95). The 5-year acute rejection-free graft survival rate was not significantly different between the groups (TCB 67%, PGF 68.8%; P=0.6286). The incidence of adverse events including adverse cardiovascular or cerebrovascular events, malignancies, new-onset diabetes after transplantation, and infection events did not differ significantly between the two groups. We conclude that TCB is a comparable alternative to the original tacrolimus as a first-line immunosuppressive drug. Producers of generics should support further study of their products after approval to assure physicians of their efficacy and safety.

Tacrolimus for children with refractory nephrotic syndrome: a one-year prospective, multicenter, and open-label study of Tacrobell®, a generic formula

BACKGROUND

Cyclosporine A and tacrolimus (TAC) are often used as a second-line treatment for children with refractory nephrotic syndrome (NS). This study was undertaken to investigate the efficacy and safety of Tacrobell®, a locally produced generic form of TAC.

METHODS

This study was a one-year prospective, open-label, single-arm, multicenter trial. Fourty-four children with steroid-dependent NS (SDNS) and 33 children with steroid-resistant NS (SRNS) were enrolled. The primary endpoints were defined as the remission rates, whereas the secondary endpoints were recognized as the duration of remission and adverse effects of TAC.

RESULTS

After one-year treatment, 34 (77.3%) of the 44 patients with SDNS were in complete remission, and 6 (13.6%) were in partial remission. Nineteen (43.2%) patients did not relapse during the study; for those who did relapse, the mean duration of remission was 4.6±2.9 months. The number of relapse episodes during the study period (0.90 per patient-year) was significantly lower than that in the preceding year (2.8 per patient-year). After treatment for 3 and 6 months, 12 (36.4%) of the 33 patients with SRNS were in remission, and after treatment for 12 months, the number of patients had increased to 13 (39.4%). The mean time to achieve remission was 4.0±3.2 months. After remission (duration, 3.7±2.7 months), 12 (54.5%) of 22 patients relapsed. The fasting blood glucose and blood pressure levels during the therapy were similar to those at the time of study entry.

CONCLUSIONS

Treatment with Tacrobell® was effective and safe for children with refractory NS. The efficacy of this generic form of TAC was better than that of the original TAC formula.

Safety and efficacy of the switch to generic mycophenolate mofetil and tacrolimus in heart transplant patients

BACKGROUND

Generic immunosuppressants may offer economic advantages, but their use is still controversial. At our center, 55 heart transplant patients were switched from CellCept(®) to Myfenax Teva(®) (MT) (n = 51, 18% female, 8.1 ± 6.6 yr post-transplantation) and/or Prograf(®) to Tacrolimus Sandoz(®) (TS) (n = 17, 41% female, 6.6 ± 5.8 yr post-transplantation).

METHODS

We conducted an acute monitoring and a retrospective follow-up with regard to safety and efficacy. Acute cellular rejections (ACRs) on endomyocardial biopsies (EMBs) four wk after the MT switch were specifically compared to a matched retrospective control group.

RESULTS

Tacrolimus C0 levels (TS switch) as well as hemoglobin, leukocytes, and thrombocytes (MT switch) did not change (p = NS) during the three wk after each respective switch (8.7 ± 2.9 vs. 8.4 ± 1.9 μg/L, 129.1 ± 12.6 vs. 130.1 ± 12.8 g/L, 6.3 vs. 6.2 × 10(9) /L, and 217.4 ± 56.6 vs. 219.3 ± 61.8 × 10(9) /L, respectively). 0% of the EMBs in the MT switch vs. 3% of the EMBs in the control group showed ACR>grade 1R (p = NS). After six months, survival was 96% (MT switch) and 100% (TS switch), and the frequency of severe ACR was low. Safety parameters measured at the next annual follow-up were also stable following each switch.

CONCLUSION

Switching to MT and/or TS several years after heart transplantation appeared safe in the short-term perspective, showing no detectable changes in tacrolimus C0 levels, safety or efficacy, during an average follow-up of six months.

Case report: Inability to achieve a therapeutic dose of tacrolimus in a pediatric allogeneic stem cell transplant patient after generic substitution

Background

Tacrolimus is an immunosuppressive drug that is used to lower the activity of the patient’s immune system to prevent organ rejection. Unfortunately, there is limited data regarding the therapeutic equivalency of generic tacrolimus formulations especially in children. We report the case of a pediatric patient having an inability to achieve a therapeutic trough level for tacrolimus after conversion from brand name to the generic formulation.

Case presentation

A 17-month-old male patient diagnosed with T-cell acute lymphoblastic leukemia underwent allogeneic stem cell transplantation. The patient initially received intravenous (IV) tacrolimus for graft-versus-host disease (GVHD) prophylaxis and achieved therapeutic levels. The patient was then switched to an oral brand formulation of tacrolimus, and was able to maintain trough levels within the therapeutic range. After being discharged, the patient received the generic formulation of tacrolimus from an outside pharmacy and the care team was unable to reach therapeutic levels despite multiple dose escalations. Returning to brand name tacrolimus resulted in prompt achievement of therapeutic levels.

Conclusions

A likely etiology for the inability to achieve therapeutic trough levels in this patient is the change in formulation from brand formulation to generic version. Other factors including drug-drug interaction, preparation of the medication by a different pharmacy, drug-food interaction and genetic factors were also considered. Physicians and pharmacists must be aware of the inability to achieve targeted therapeutic concentrations of tacrolimus resulting from the conversion of brand name to the generic formulation until these generic formulations are tested in clinical trials in a pediatric population.

Mizoribine versus mycophenolate mofetil in combination therapy with tacrolimus for de novo kidney transplantation: evaluation of efficacy and safety

The present study compared the efficacy and safety of mizoribine (MZR) with mycophenolate mofetil (MMF) in kidney transplantation. This multicenter, randomized clinical trial. Employed doses of study drug tailored to the immunosuppressive need. The primary efficacy outcome was the incidence of biopsy-proven acute rejection episodes (BPAR). The safety of the study drug was assessed using the incidences of adverse events, drug discontinuations, and abnormal laboratory results. The 7 (6.4%) BPARs above grade II were observed in the MZR group noninferior to the 2 (1.8%) in the MMF group (95% confidence interval, -0.007-0.097 > noninferiority limit [-0.2]). BPAR was significantly decreased in the MZR group after the dose change (17/41 [41.4%] vs 8/69 [11.6%]; P < .0001) and the incidence of BPAR was similar between the MZR and MMF groups after the dose change (P = .592). The uric acid level was significantly elevated in the MZR group (P = .002). In conclusion, the efficacy and safety of MZR were similar and statistically noninferior to MMF in combination therapy with tacrolimus.

A single-centre comparison of the clinical outcomes at 6 months of renal transplant recipients administered Adoport® or Prograf® preparations of tacrolimus

BACKGROUND

The use of generic formulations of immunosuppressive drugs in place of brand name drugs offers considerable cost savings. Brand name tacrolimus (Prograf^®) came off patent in April 2008. However, published evidence supporting therapeutic equivalence of generic formulations of tacrolimus in solid organ transplantation is lacking. The South West Transplant Centre switched from administering Prograf^® to a generic formulation (Adoport^®) for de novo transplant recipients in November 2010. This study sought to compare the clinical outcomes of renal transplant recipients administered Prograf^® with those receiving Adoport^®.

METHODS

Data regarding patient characteristics and clinical outcomes were collected retrospectively for all patients undergoing renal transplantation at the South West Transplant Centre between 8 November 2009 and 8 November 2011 to whom tacrolimus was prescribed.

RESULTS

A total of 48 patients received Prograf^® and 51 received Adoport^®. At 6 months, no statistically significant differences were identified in the rates of patient survival, graft survival, acute allograft rejection, delayed graft function, calcineurin inhibitor toxicity or cytomegalovirus infection occurring within the two groups.

CONCLUSIONS

This is the first study to compare the clinical outcomes of patients receiving Adoport^® with those receiving brand name tacrolimus. We report comparable clinical outcomes at 6 months in patients receiving either Prograf^® or Adoport^® from the time of renal transplantation. These early outcome data therefore support the use of Adoport^® in place of Prograf^® as a potential cost-saving measure.

Generic immunosuppression in solid organ transplantation: a Canadian perspective

The introduction of generic immunosuppressant medications may present an opportunity for cost savings in solid organ transplantation if equivalent clinical outcomes to the branded counterparts can be achieved. An interprofessional working group of the Canadian Society of Transplantation was established to develop recommendations on the use of generic immunosuppression in solid organ transplant recipients (SOTR) based on a review of the available data. Under current Health Canada licensing requirements, a demonstration of bioequivalence with the branded formulation in healthy volunteers allows for bridging of clinical data. Cyclosporine, tacrolimus, and sirolimus are designated as "critical dose drugs" and are held to stricter criteria. However, whether this provides sufficient guarantee of therapeutic equivalence in SOTR remains controversial, and failure to maintain an appropriate balance of immunosuppression may have serious consequences, including rejection, graft loss, and death. Published evidence supporting therapeutic equivalence of generic formulations in SOTR is lacking. Moreover, in the setting of multiple generic formulations the potential for uncontrolled product switching is a major concern, since generic preparations are not required to demonstrate bioequivalence with each other. Although close monitoring is recommended with any change in formulation, drug product switches are likely to occur without prescriber knowledge and may pose a significant patient safety risk. The advent of generic immunosuppression will require new practices including more frequent therapeutic drug and clinical monitoring, and increased patient education. The additional workload placed on transplant centers without additional funding will create challenges and could ultimately jeopardize patient outcomes. Until more robust clinical data are available and adequate regulatory safeguards are instituted, caution in the use of generic immunosuppressive drugs in solid organ transplantation is warranted.

Generic immunosuppression: deciphering the message our patients are receiving

BACKGROUND

The introduction of generic immunosuppressants elicited controversy within the transplant community and it is unknown whether patient attitudes mirror the ambiguity of provider perceptions. With the current health care economic crisis, it is necessary to consider generic immunosuppression as an option. A greater understanding of patient perceptions would enhance vital communication between providers and patients to facilitate education and appropriate monitoring.

OBJECTIVE

To evaluate transplant recipients' perceptions of generic versus brand immunosuppressants based on experience with these agents and the willingness of patients to convert treatment from brand to generic formulations based on socioeconomic variables and baseline demographics.

METHODS

Key informant interviews were conducted to inform the development of the survey instrument. The survey was distributed to solid organ transplant recipients at a large, academic medical center from October to December 2010.

RESULTS

Nine patients participated in key informant interviews. Financial considerations and provider recommendations were the most commonly identified factors to influence perceptions of generic immunosuppressants. A total of 255 patients completed the survey; treatment in 81 (32%) participants had been converted to a generic immunosuppressant. Those currently receiving a generic immunosuppressant expressed higher beliefs of generic and brand equivalency (75% vs 54%, p = 0.006) and an increased willingness to convert treatment to a generic given equivalent cost (51% vs 32%, p = 0.024). African American participants were found to have a decreased belief of generic and brand equivalency compared to other ethnicities (60% vs 75%, p = 0.013). Participants with an annual income of less than $30,000 had higher beliefs of generic and brand equivalency (60% vs 40%, p = 0.0001). Education level and age did not impact beliefs of generic efficacy or willingness to convert therapy.

CONCLUSIONS

Patient ethnicity, income, and experience with generic immunosuppressants appear to contribute to perceptions of generic immunosuppressants. The prevalence of generic immunosuppressant use supports the importance of communication of this issue between providers and patients.

Comparison of adverse drug reaction profiles of two tacrolimus formulations in rats

Tacrobell(®) (TB) is a generic tacrolimus which showed the comparable efficacy to original product, Prograf(®) (PG) in renal transplantation, but toxicity between two drugs is unclear. The aim of this study was to compare the toxicity between these two formulations. TB and PG (0.5, 1 and 2 mg/kg/day) was administered to rats for 4 weeks. The rat survival rate, kidney, liver and pancreas injury was investigated. The survival rate was similar between TB- and PG-treated rats. TB and PG induced renal dysfunction in a dose-dependent manner. Compared to PG treatment in equal dose, TB treatment reduced urinary creatinine clearance in a less degree and renal interstitial fibrosis was comparable between two regimens. The r-glutamyl transpeptidase was aggravated by tacrolimus treatment, and this was not different between TB and PG treatment. In the intraperitoneal glucose tolerance test, a significant diabetogenic effect was observed in all tacrolimus treated-rats. The glucose tolerance of TB-treated rats was similar to those of PG-treated rats in each dose. The decrement in pancreatic β-cell mass by tacrolimus showed the dose-dependent response and it was comparable between TB and PG treatment. In conclusion, TB is similar to PG in terms of nephrotoxicity, hepatoxicity and diabetogenic effect.

Topics in transplantation medicine for general nephrologists

Before transplantation, the general nephrologist is the primary resource for potential kidney transplantation recipients. After transplantation, the general nephrologist is increasingly managing transplant medications and complications. We provide evidence-based management strategies for common clinical issues. Linking our approach with the data allows the clinician to explore each subject in greater depth to tailor care to individual patients.