Feasibility of reduced intensity hematopoietic stem cell transplantation from an HLA-matched unrelated donor

Association of the areas over and under the lymphocyte curve with cytomegalovirus reactivation after allogeneic hematopoietic stem cell transplantation

BACKGROUND

We retrospectively compared the impact of the areas over and under the lymphocyte curve (L_AOC vs L_AUC) on cytomegalovirus (CMV) reactivation after allogeneic hematopoietic stem cell transplantation (HSCT).

METHODS

Among 394 consecutive patients who underwent their first allogeneic HSCT at our center between 2007 and 2018, 301 patients met the inclusion criteria. L_AOC was calculated as the area over the lymphocyte curve during lymphopenia (absolute lymphocyte count [ALC] <700/μL). We calculated L_AOC and L_AUC from day 0 to day 15 (L_AOC15, L_AUC15) and from day 0 to day 30 (L_AOC30, L_AUC30).

RESULTS

CMV antigenemia was defined as more than 3 cells/2 slides by the C10/11 method and detected in 204 cases (CMV reactivation) at a median of 39 days after HSCT. Although there were significant differences in L_AOC15, L_AOC30, L_AUC15, and L_AUC30 between patients with and without CMV reactivation, there was no difference in accuracy for predicting CMV reactivation between L_AOC and L_AUC. In a multivariate analysis, L_AOC15 and L_AUC15 were each identified as independent predictive factors for CMV reactivation, along with advanced age and CMV serostatus. However, ALC at day 14 or day 21 was as accurate as area-based indexes such as L_AOC15 and L_AUC15. L_AOC15 and L_AUC15 were significantly associated with longer duration of anti-CMV antiviral therapy while ALC was not.

CONCLUSIONS

L_AOC15 and L_AUC15 had similar impacts on CMV reactivation. Although these area-based indexes were not superior to ALC for predicting CMV reactivation, they might predict patients who need longer duration of antiviral therapy more accurately.

Impact of the patient's body weight on the efficacy and adverse events of valganciclovir for cytomegalovirus reactivation after hematopoietic stem cell transplantation

While the dose of ganciclovir (GCV) is decided base on patients' body weight (BW), that of valganciclovir (VGCV) is fixed as 900 or 1800 mg/d regardless of the patient's BW in preemptive therapy for cytomegalovirus (CMV) reactivation in hematopoietic stem cell transplantation. We analyzed the impact of the patient's BW on the effectiveness and adverse events (AEs) of VGCV. From March 2004 to February 2017, 27 patients received VGCV as a first-line treatment for CMV reactivation. As a historical control group, we extracted 17 patients who started to receive GCV at a similar timing. We used the following definitions of outcomes: speed of reduction of CMV antigenemia (CMV-AG) as a measure of effectiveness, ratios of baseline and minimum value for white blood cell (WBC) and platelet counts, and ratio of baseline and maximum values for serum creatinine (sCr) as measures of AEs. As a result, there was no significant correlation between average daily dose of VGCV with or without adjusting for the patient's BW and speed of reduction of CMV-AG. On the other hand, the decreases in WBC and platelets and the increase in sCr were significantly correlated with the cumulative dose of VGCV. However, the absolute values of the correlation coefficients did not increase when we analyzed the correlations between the BW-adjusted cumulative dose of VGCV and factors associated with adverse events. There were no significant differences in efficacies or AE parameters between the GCV and VGCV groups. In conclusion, the patient's BW did not significantly affect the effectiveness or adverse events of VGCV.

Feasibility of salvage cord blood transplantation using a fludarabine, melphalan, and low-dose anti-thymocyte globulin conditioning regimen

Primary graft failure (PGF) is a lethal complication that occurs early after allogeneic stem cell transplantation (allo-SCT). Cord blood transplantation (CBT) is a potential re-transplantation option. Total body irradiation (TBI) is often incorporated into the pre-salvage CBT conditioning regimen following PGF; however, patients experiencing PGF are not always amenable to TBI, and non-TBI regimens for salvage CBT should be established. Here, we report five patients with hematologic malignancies who received salvage CBT for PGF following a non-TBI regimen using fludarabine (Flu), melphalan (Mel), and low-dose anti-thymocyte globulin (ATG). The median intervals between the failed allo-SCT and salvage CBT, as well as between the diagnosis of PGF and salvage CBT, were 37 days and 8 days, respectively. The median neutrophil recovery period was 21 days (range 18-21 days). Four of five patients achieved neutrophil engraftment following salvage CBT; all four exhibited sustained engraftment with complete donor chimerism. Three of the five patients were alive after a median follow-up time of 907 days (range 315-909 days) post-salvage CBT; two patients died of causes unrelated to recurrence. These data suggest that CBT following the non-TBI regimen described here is feasible in patients with PGF.

A prospective dose-finding trial using a modified continual reassessment method for optimization of fludarabine plus melphalan conditioning for marrow transplantation from unrelated donors in patients with hematopoietic malignancies

BACKGROUND

Because of the less graft-facilitating effect by bone marrow (BM), we need to assess a dosage of conditioning more accurately particularly in combination with reduced-intensity conditioning. Thus we examined that modified continual reassessment method (mCRM) is applicable for deciding appropriate conditioning of allogeneic BM transplantation.

PATIENTS AND METHODS

The conditioning regimen consisted of i.v. fludarabine (125 mg/m2) plus an examination dose of i.v. melphalan. The primary endpoint was a donor-type T-cell chimerism at day 28 with successful engraftment defined as >90% donor cells. Five patients per dose level were planned to be accrued and chimerism data were used to determine the next dose.

RESULTS

Seventeen patients were enrolled at doses between 130 and 160 mg/m2. The dose was changed from 160 to 130 mg/m(2) (second level) after five full-donor chimerisms. With one patient of 0% chimera in the second level, the dose was increased to 135 mg/m2 (third level). Following five full-donor chimerisms in the third level, the study was complete as projected.

CONCLUSIONS

mCRM was shown to be a relevant method for dose-finding of conditioning regimen. The melphalan dose of 135 mg/m2 was determined as the recommended phase II dose to induce initial full-donor chimerism.

Tacrolimus as prophylaxis for acute graft-versus-host disease in reduced intensity cord blood transplantation for adult patients with advanced hematologic diseases

BACKGROUND

Myeloablative cord blood transplantation (CBT) for adult patients offers a 90% chance of engraftment with a 50% rate of transplant-related mortality, mostly attributable to infection. We have demonstrated the feasibility of reduced-intensity CBT (RI-CBT) for adult patients, in which cyclosporine was used for acute graft-versus-host disease (GVHD) prophylaxis. Transplantation-related mortality (TRM) was 27% within 100 days. Therefore our objective was to evaluate the feasibility of RI-CBT with tacrolimus as GVHD prophylaxis for adult patients with hematologic malignancies.

METHODS

Thirty-four patients with a median age of 56.5 years (range; 22-68) with hematologic diseases underwent RI-CBT at Toranomon Hospital between November 2003 and September 2004. Preparative regimen comprised fludarabine 25 mg/m2 on days -7 to -3, melphalan 80 mg/m2 on day -2, and 4 Gy total body irradiation on day -1. GVHD prophylaxis was continuous intravenous infusion of tacrolimus 0.03 mg/kg, starting on day -1.

RESULTS

Thirty-one patients achieved neutrophil engraftment at a median of day 20. Median infused total cell dose was 2.4 x 10E7/kg (range; 1.6-4.8). Thirty-two patients achieved complete donor chimerism at day 60. Grade II-IV acute GVHD occurred in 45% of patients, with a median onset of day 26. Primary disease recurred in five patients, and TRM within 100 days was 12%. Estimated 1-year overall survival was 70%.

CONCLUSION

This study demonstrated the possible improvement in transplant-related mortality by tacrolimus as GVHD prophylaxis in adult RI-CBT recipients.

Current status of reduced-intensity allogeneic stem cell transplantation using alternative donors

The optimal donor for a patient undergoing reduced-intensity stem cell transplantation remains a human leukocyte antigen (HLA)-matched relative. Alternative donors such as matched unrelated donors (MUDs), mismatched related donors (haploidentical), or unrelated umbilical cord blood (UCB) units have emerged as options as well. The most experience thus far has been with MUD donors, mostly attributed to the development of allele-specific DNA-based HLA-typing methods. The biggest drawback remains the significant delay needed to locate a donor. Haploidentical donors exist for almost all patients, and offer the convenience of a living related donor. However, significant rates of graft-versus-host disease (GVHD) and other toxicities continue to complicate such HLA mismatching. UCB is the most recent option for source of stem cells. Frozen cord blood units can be acquired almost immediately and are able to safely traverse 1 or 2-HLA antigen mismatch barriers. The experience with UCB has been limited by the low cell dose, although recent innovations are attempting to overcome this. In this review, we summarize the current experience and knowledge with alternative donors as stem cell sources for reduced-intensity transplantation.

Cytomegalovirus infections following umbilical cord blood transplantation using reduced intensity conditioning regimens for adult patients

Cytomegalovirus (CMV) infection is a major complication after allogeneic hematopoietic stem cell transplantation (Allo-HSCT); however, we have little information on the clinical features of CMV reactivation after cord blood transplantation using reduced-intensity regimens (RI-CBT) for adults. We reviewed medical records of 140 patients who underwent RI-CBT at Toranomon Hospital between January 2002 and March 2005. All the patients were monitored for CMV-antigenemia weekly, and, if turned positive, received preemptive foscarnet or ganciclovir. Seventy-seven patients developed positive antigenemia at a median onset of day 35 (range, 4-92) after transplant. Median of the maximal number of CMV pp65-positive cells per 50,000 cells was 22 (range, 1-1806). CMV disease developed in 22 patients on a median of day 35 (range, 15-106); 21 had enterocolitis and 1 had adrenalitis. CMV antigenemia had not been detected in 2 patients, when CMV disease was diagnosed. CMV disease was successfully treated using ganciclovir or foscarnet in 14 patients. The other 8 patients died without improvement of CMV disease. In multivariate analysis, grade II-IV acute graft-versus-host disease was a risk factor of CMV disease (relative risk 3.48, 95% confidential interval 1.47-8.23). CMV reactivation and disease develop early after RI-CBT. CMV enterocolitis may be a common complication after RI-CBT.

Antifungal prophylaxis following reduced-intensity stem cell transplantation

Reduced-intensity stem cell transplantation (RIST) has been developed to be a novel curative option for advanced hematologic diseases. Its minimal toxicity allows for transplantation in patients with advanced age or with organ dysfunction. Young patients without comorbidity can undergo RIST as outpatients. However, fungal infection remains an important complication in RIST. Given the poor prognosis of fungal infection, prophylaxis is critical in its management. The prophylactic strategy is recently changing with the development of RIST. Hospital equipment is important for fungal prophylaxis; however, the median day for the development of fungal infection is day 100, when most RIST patients are followed as outpatients. The focus of fungal management after RIST needs to shift from in-hospital equipment to oral antifungals. Various antifungals have recently been developed and introduced for clinical use. A major change in antifungal management will probably occur within several years.

Stable Engraftment after a Conditioning Regimen with Fludarabine and Melphalan for Bone Marrow Transplantation from an Unrelated Donor

Graft failure and nonrelapse mortality (NRM) are major obstacles after the first unrelated-donor bone marrow transplantation (UD-BMT) with reduced-intensity conditioning. We evaluated UD-BMT with fludarabine (5 x 25 mg/m2) and melphalan (2 x 90 mg/m2) treatment combined with short-term methotrexate and tacrolimus (n = 20) or cyclosporine (n = 2) therapy for 22 patients with hematologic malignancies who were ineligible for conventional conditioning. Only 9 patients were in remission at transplantation. Seventeen patients underwent HLA-matched or DRB1 allele-mismatched transplantation, and 5 patients underwent HLA-A allele-mismatched or serologically HLA-DR-mismatched transplantation. Regimen-related toxicities were tolerable, although transient oral mucositis, hepatobiliary enzyme elevation, and diarrhea were observed frequently. All evaluable patients achieved sustained neutrophil engraftment, and all patients tested showed complete donor chimerism on day 28. With a median follow-up of 16 months, NRM and overall survival rates at 1 year were 19% and 81%, respectively, among the patients who underwent HLA-matched or DRB1 allele-mismatched transplantation. Acute graft-versus-host disease (GVHD) of grades II to IV occurred in 26% of the patients. The cumulative incidence of chronic GVHD was 44%. Despite the small number of patients and the short follow-up period, this reduced-intensity regimen enabled satisfactory engraftment and achievement of rapid complete donor chimerism with tolerable toxicities in the patients, including those who underwent HLA-mismatched UD-BMT.

Severe pulmonary complications in Japanese patients after bortezomib treatment for refractory multiple myeloma

Bortezomib is a novel proteasome inhibitor with significant antimyeloma activity. Its frequent adverse effects are manageable, including gastrointestinal symptoms, peripheral neuropathy, and thrombocytopenia. Severe lung toxicity has not previously been reported. Between June 2004 and September 2005, 13 Japanese patients with multiple myeloma were treated with bortezomib in Toranomon Hospital, Juntendo University School of Medicine, and Jichi Medical School. Four of them developed severe pulmonary complications, and 2 died of respiratory failure without progression of underlying disease. To our knowledge, this is the first report on life-threatening pulmonary adverse effects after bortezomib therapy. Previous clinical studies on bortezomib, mostly in the United States and Europe, have shown low incidences of pulmonary adverse effects. Our study suggests that bortezomib can cause serious lung injury, and that its incidence might vary among different ethnicities. Clinicians need to be alert to the possibility.

Graft failure following reduced-intensity cord blood transplantation for adult patients

We reviewed the medical records of 123 adult reduced-intensity cord blood transplantation (RI-CBT) recipients to investigate the clinical features of graft failure after RI-CBT. Nine (7.3%) had graft failure, and were classified as graft rejection rather than primary graft failure; they showed peripheral cytopenia with complete loss of donor-type haematopoiesis, implying destruction of donor cells by immunological mechanisms rather than poor graft function. Three of them died of bacterial or fungal infection during neutropenia. Two recovered autologous haematopoiesis. The remaining four patients underwent a second RI-CBT and developed severe regimen-related toxicities. One died of pneumonia on day 8, and the other three achieved engraftment. Two of them died of transplant-related mortality, and the other survived without disease progression for 9.0 months after the second RI-CBT. In total, seven of the nine patients with graft failure died. The median survival of those with graft failure was 3.8 months (range, 0.9-15.4). Graft failure is a serious complication of RI-CBT. As host T cells cannot completely be eliminated by reduced-intensity preparative regimens, we need to be aware of the difficulty in differentiating graft rejection from other causes of graft failure following RI-CBT. Further studies are warranted to establish optimal diagnostic and treatment strategies.

Intensive graft-versus-host disease prophylaxis is required after unrelated-donor nonmyeloablative stem cell transplantation

Nonmyeloablative stem cell transplantation (NST) harnesses the graft-versus-tumor effect while minimizing regimen-related toxicity, and can result in donor chimerism and remission. Acute graft-versus-host disease (GVHD) and infections are major complications after sibling NST. Toxicity of unrelated-donor (UD) NST and the most appropriate GVHD prophylaxis in this setting remain poorly defined. We describe 25 patients who received UD-NST conditioned with fludarabine and cyclophosphamide. The first six patients received cyclosporine (Cs) and mycophenolate mofetil (MMF) (n=5) or methotrexate (MTX) (n=1) as GVHD prophylaxis (group 1) and all developed grade III-IV acute GVHD. The next 19 patients received the same conditioning regimen with the addition of alemtuzumab, and all received Cs/MTX post-transplant. Engraftment and donor chimerism were achieved in all but one evaluable patient. In all, 15 patients died: five of six deaths in group 1 were attributable to acute GVHD, while deaths in group 2 were due to infection or progressive disease (P=0.05). The combination of Cs/MMF is inadequate GVHD prophylaxis for UD-NST. The use of Cs, MTX, and alemtuzumab eliminated severe acute GVHD; its impact on response merits further study.