Alemtuzumab in Lung Transplantation: An Open-Label, Randomized, Prospective Single Center Study

Study design

The study was an open-label, controlled, randomized study, conducted at the General Hospital Vienna, Medical University of Vienna (EudraCT number: 2007-001815-51). Patients were randomized 1:1 into two treatment arms: group A received alemtuzumab (Campath-1H; Berlex, Montville, NJ) 30 mg one single dose combined with tacrolimus (target trough level 10–12 ng/mL first 3 months, 8–10 ng/mL months 4–24), MMF (1.5 g/day) and corticosteroids in a reduced dosage regime. Group B received IMTIX-Sangstat ATG-induction on days 0–4 with a dosage of 5 mg/kg body weight combined with tacrolimus (target trough level 15–18 ng/mL first 3 months, 12–15 ng/mL months 4–24), MMF (3 g/day) and corticosteroids at standard levels. Actual trough levels are listed in Table 1. Randomization took place immediately after TX using the Randomizer for Clinical Trials 1.8.1 (Copyright © 2002–2013 Institute for Medical Informatics, Statistics and Documentation, Medical University of Graz).

Study drug was not blinded due to the use of different maintenance drug regimens. The study was funded by Astellas Pharma Austria and approved by the institutional ethic review board. A written informed consent was provided by each participant before enrollment.

We initiated a controlled, prospective randomized study in which patients were randomly assigned to receive either alemtuzumab, tacrolimus, MMF and corticosteroids in a reduced dosage regime or ATG-induction together with standard-dosed tacrolimus, MMF and corticosteroids.

Availability of alemtuzumab

Since August 2012 Genzyme has surrendered the license of alemtuzumab. This means that alemtuzumab is no longer available as a licensed product in Europe. This action was not being taken for any reasons related to product safety, efficacy or supply, but as the company's plan for bringing alemtuzumab forward as a treatment for a new indication. The company will continue to supply alemtuzumab commercially through a patient access program for oncological and transplant indications.

Study objectives and hypothesis

The objective of the study was to compare the safety and efficacy of the two regimens in patients undergoing lung or combined heart-lung TX with regard of drug-related complications and over or under IS-associated complications.

We hypothesized that alemtuzumab with low triple IS would be associated with reduced ACR episodes and, due to the reduction of kidney toxicity, improved GFRs at 6, 12 and 24 months.

Sample size determination was based on an evaluation of the ability to detect the superiority of alemtuzumab induction in combination with dose reduced triple IS. Primary end point was GFR after 6 and 12 months.

Secondary end points were patient and graft survival, recurrent and ongoing rejection episodes, infectious complications and freedom from bronchiolitis obliterans syndrome (BOS).

The study was designed to continue to 2 years to assess safety and efficacy.

Infectious prophylaxis

All patients routinely received antibiotic prophylaxis with piperacillin/tazobactam for 2 weeks postoperatively. Cystic fibrosis patients and patients with recurrent infections received antibiotics according to resistance testing. Further evaluations including rejection and infection monitoring by transbronchial biopsy and lavage were routinely performed according to the center standards.

All patients received cytomegalovirus (CMV) prophylaxis with at least 2 weeks of intravenous (IV) ganciclovir followed by an oral therapy until the end of the third postoperative month. High-risk patients (donor CMV positive/recipient CMV negative) were treated for 12 months, if tolerated, in combination with CMV hyperimmunoglobulin (1 mL/kg IV day 1, 7, 14 and 21 postop) (Cytotect-Biotest; Biotest Austria GmbH, Wien, Austria) 12, 13. Furthermore, every patient received Pneumocystis carinii prophylaxis indefinitely as well as aerosolized amphotericin B for antifungal prophylaxis for at least 3 months after TX.

Follow-up

Surveillance bronchoscopies with transbronchial biopsy were performed 2 weeks, 1, 2, 3, 6, 9 and 12 months after TX. In addition, bronchoscopies with biopsy were performed as clinically indicated for suspected rejection, infection or other pulmonary problems. All diagnoses of acute rejection were confirmed with biopsy specimens using standard histological criteria and grading. The first episode of acute rejection was treated with a 3-day course of high-dose methylprednisolone (500–1000 mg/day), and, if the maintenance prednisone dose had been tapered, it was gradually decreased back to the previous dose over 2–4 weeks.

CMV infection was defined as an increase in viral load detected using quantitative CMV polymerase chain reaction >1000 copies/mL. CMV disease was defined as CMV DNAemia in combination with symptoms and signs of organ involvement together with evidence of localized CMV infection on a biopsy or other appropriate specimen. CMV syndrome was defined as CMV DNAemia in combination with fever. Patients with positive bronchoalveolar lavage were counted as CMV pneumonitis if they had a compatible clinical and radiological picture. Bacterial colonization was defined as the presence of bacteria without clinical signs or symptoms and no or a preemptive treatment given. Bacterial infection was defined as the presence of bacteria with clinical signs and symptoms, and treatment.

BOS was graded by two experienced transplant physicians following the ISHLT guidelines. There were no discrepancies in grading or time of onset between the two reviewers in all BOS cases.

Kidney function was monitored by measurement of GFR, which was calculated from the creatinine concentration in the collected urine sample, urine flow rate and the plasma concentration.

Study patients

Patient enrollment started in January 2009 and ended in April 2010. A total of 60 patients were enrolled, 30 receiving alemtuzumab and 30 ATG. Baseline characteristics of the study patients are given in Table 2.

Tolerability of induction agents

Both antibody infusions were administered immediately as possible after arrival on the intensive care unit postoperatively. Patients from the alemtuzumab group received 30 mg alemtuzumab over 2 h just one time.

Patients from the thymoglobulin group received 2 mg ATG/kg body weight on days 0, 1, 2, 3 and 4 postoperative over 4 h.

Both agents were generally well-tolerated without significant side effects.

Survival

There were no significant differences in 1- and 2-year survival (alemtuzumab 93% vs. ATG 96%, 90% vs. 96%, respectively, p = 0.1) (Figure 1).

Reasons for death were in all cases severe infections, one due to invasive aspergillosis. In one case re-TX due to bronchial stenosis was performed (Table 3).

Episodes of acute rejection

The number of ACR episodes ≥ A2 within the first year post-TX was significantly lower in group A (alemtuzumab 0 vs. ATG five events in five patients; p = 0.019) (Figure 2); no recurrent or ongoing ACR was observed. Low-grade ACR (ISHLT grade A1) was observed in four patients from the alemtuzumab group and in two patients from the ATG cohort (p = 0.5). Lymphocytic bronchiolitis (LB) within the first year post-TX was not different between the groups (cumulative B scores group A 2.9 ± 2.7 vs. group B 3.2 ± 2.3/patient/year, p = 0.74) (Table 3).

Infectious complications

There were no significant differences in bacterial (group A 2.1 ± 2.3 per patient vs. group B 2.3 ± 2.0, p = 0.95), CMV (group A 0.43 ± 0.5 per patient per vs. group B 0.4 ± 0.5, p = 0.79) or Aspergillus infections (group A 0.2 ± 0.4 vs. group B 0.13 ± 0.34, p = 0.49, respectively) within the first year between the groups (Table 3).

Kidney function

GFRs (mL/min) after 1 and 2 years also were not different (group A 62.4 ± 30.4 vs. group B 53.8 ± 23.3, p = 0.2, group A 56.7 ± 25.9 vs. group B 61.0 ± 27.2, p = 0.5, respectively) between both groups (Table 3).

Chronic organ dysfunction

Within the first 2 years post-TX four patients of group A (13%) and one patient of group B (3%) developed BOS≥1 (p = 0.19) (Figure 3 and Table 3).

Adverse events

The mean follow-up of the study cohort was 1330 ± 379 days with a range between 231 and 1835 days. Follow-up was 100% complete.

One patient of group B developed malignancy of the lung (adenocarcinoma) 884 days post-TX. Episodes of leukopenia (<4000 G/L) within the first 2 years were frequent in both groups (group A [n = 23], group B [n = 14], p = 0.01) with a significant earlier and higher incidence after use of alemtuzumab (Table 3). In all cases of leukopenia MMF was stopped until leukocyte count normalized. In cases of severe leukopenia (<1500 G/L) granulocyte colony-stimulating factor was administered.

Lymphocyte subpopulations

CD3 and CD19 counts were measured every 3 months during the study period. T lymphocytes (CD3 cells) decreased in both study groups with a significant lower count in the alemtuzumab cohort and recovered after 12–18 months in both groups. CD19 counts decreased in the alemtuzumab group within the first 12 months significantly and recovered after 18–24 months; the ATG group showed a decrease after 3–6 months and recovered after 18–24 months post-LUTX.

CD3 counts after 1, 6 and 12 months: ATG group versus alemtuzumab: 319 ± 353 versus 156 ± 428 (p = 0.13), 645 ± 396 versus 290 ± 276 (p = 0.013), 682 ± 377 versus 586 ± 612 (p = 0.5) cells/µL. CD19 counts after 1, 6 and 12 months: ATG versus alemtuzumab: 136 ± 102 versus 34 ± 113 (p = 0.01), 104 ± 80 versus 40 ± 72 (p = 0.02), 99 ± 92 versus 52 ± 45 (p = 0.05) cells/µL.