Reduced-intensity allogeneic hematopoietic stem cell transplantation in metastatic colorectal cancer as a novel adoptive cell therapy approach. The European group for blood and marrow transplantation experience.

Reduced-intensity conditioning (RIC) regimens for allogeneic hematopoietic stem cell transplantation (HCT) allowed the existence of an allogeneic cell-mediated antitumor effect in metastatic colorectal cancer (mCRC) to be explored. We report on 39 patients with progressing mCRC treated with different RIC regimens in a multicenter clinical trial of the European Bone Marrow Transplantation Group. Disease status at transplant was progressive disease (PD) in 31 patients (80%), stable disease (SD) in 6 (15%), and partial response (PR) in 2 (5%). All patients engrafted (median donor T cell chimerism of 90% at day +60). Transplant-related morbidities were limited. Grades II-IV acute graft-versus-host disease (aGVHD) occurred in 14 patients (35%) and chronic GVHD (cGVHD) in 9 patients (23%). Transplant-related mortality occurred in 4 patients (10%). The best tumor responses were: 1 complete response (CR) (2%), 7 PR (18 %), and 10 SD (26%), giving an overall disease control in 18 of 39 patients (46%). Allogeneic HCT after RIC is feasible; the collected results compared favorably in terms of tumor response with those observed using conventional approaches beyond second-line therapies. The study of an allogeneic cell based therapy in less advanced patients is warranted.

Inflammatory cytokines predominate in cases of tumor regression after hematopoietic stem cell transplantation for solid cancer.

Allogeneic hematopoietic stem cell transplantation (SCT) has recently been presented as promising immunotherapy against renal cell, colon, ovarian, breast, and primary liver cancer. Because clinical results demonstrate a variable effect on metastases, we studied whether there is an association between the clinical response and free cytokines in serum. Two patients with metastatic colorectal and 4 with renal cell cancer underwent allogeneic SCT. Conditioning included fludarabine (30 mg/m2) for 3 or 5 days, using sibling or matched unrelated donors, respectively, followed by 2 Gy total body irradiation (n=5) or cyclophosphamide (60 mg/kg) for 2 days (n=1). Antithymoglobuline (4 mg/kg) was given to patients with matched unrelated donors (n=3). Immunosuppression was cyclosporin A, combined with mycophenolate mofetil (n=5) or methotrexate (n=1). The tumor load was examined by computer tomography of the thorax and abdomen before and 3, 6, 9, and 12 months after SCT. Free cytokines in serum were analyzed using enzyme-linked immunosorbent assay. In each patient, the ratio between inflammatory (I) and anti-I cytokines was calculated. No statistical significance was found between the cytokine ratio in correlation to the tumor load according to international response evaluation criteria in solid tumors criteria. In contrast, tumor regression was found to correlate with dominating I cytokine levels in 5/7 occasions, compared with 1/12 of cases with anti-I cytokines using our local method focusing on metastases in lungs, lymph nodes, and liver (P=.01). Thus, an increased level of I cytokines possibly mirrors tumor killing induced by type 1 T-cell response. Furthermore, anti-I cytokines might inhibit cytotoxic cells from exerting the antitumor effect of allogeneic SCT.

Liver transplantation followed by adjuvant nonmyeloablative hemopoietic stem cell transplantation for advanced primary liver cancer in humans.

BACKGROUND: Tumor recurrence after orthotopic liver transplantation (OLT) in patients with advanced primary liver cancer is common. To achieve an adjuvant graft-versus-tumor effect, the authors investigated whether transplantation of allogeneic peripheral blood stem cells (PSCT) after OLT can induce sustained complete donor chimerism. METHODS: Five patients with advanced primary liver cancer were included in the trial. None of the patients had signs of extrahepatic tumor before OLT. However, overall, the extent of surgery, as judged by morphologic examination of the explanted liver, was considered inadequate. A nonmyeloablative preparative regimen of fludarabine combined with total-body irradiation or cyclophosphamide preceded the allogeneic PSCT, which was then performed 16 to 135 days after OLT with human leukocyte antigen-matched donors. Mixed chimerism was monitored weekly by polymerase chain reaction of variable number tandem repeats after PSCT. RESULTS: In two patients, no engraftment of donor cells was seen, whereas one rejected the cells 2 months after PSCT. In two of the patients, a stable mixed donor chimerism was established. A mild transient graft-versus-host reaction was also noted in two patients. Three of the patients died of progressive disease 7 to 9 months after OLT. The other two are presently alive without recurrence at a follow-up of 26 and 10 months, respectively. CONCLUSIONS: These data suggest that PSCT after OLT is feasible, with low transplant-related morbidity. The rate of nonengraftment or rejection of the transplanted stem cells in this group of patients was three of five. An augmented pretreatment to prevent donor T-cell rejection seems to be necessary in this setting.

Home care during the pancytopenic phase after allogeneic hematopoietic stem cell transplantation is advantageous compared with hospital care.

After myeloablative treatment and allogeneic stem cell transplantation (SCT), patients are kept in isolation rooms in the hospital to prevent neutropenic infections. During a 3-year period, patients were given the option of treatment at home after SCT. Daily visits by an experienced nurse and daily phone calls from a physician from the unit were included in the protocol. We compared 36 patients who wished to be treated at home with 18 patients who chose hospital care (control group 1). A matched control group of 36 patients treated in the hospital served as control group 2. All home care patients had hematologic malignancies and 19 were in first remission or first chronic phase. Of the donors, 25 were unrelated. The patients spent a median of 16 days at home (range, 0-26 days). Before discharge to the outpatient clinic after SCT, patients spent a median of 4 days (range, 0-39 days) in the hospital. In the multivariate analysis, the home care patients were discharged earlier (relative risk [RR] 0.33, P =.03), had fewer days on total parenteral nutrition (RR 0.24, P <.01), less acute graft-versus-host disease (GVHD) grades II-IV (RR 0.25, P =.01), lower transplantation-related mortality rates (RR 0.22, P =.04), and lower costs (RR 0.37, P <.05), compared with the controls treated in the hospital. The 2-year survival rates were 70% in the home care group versus 51% and 57% (not significant) in the 2 control groups, respectively (P <.03). To conclude, home care after SCT is a novel and safe approach. This study found it to be advantageous, compared with hospital care.

Clinical tolerance after allogeneic hematopoietic stem cell transplantation: a study of influencing factors.

BACKGROUND: Clinical tolerance, defined as discontinuation of immunosuppression without immunological events, is often achieved after allogeneic hematopoietic stem cell transplantation, unlike after organ transplantation. However, this phenomenon has rarely been studied. METHODS: Between September 1977 and December 1997, we evaluated 354 allogeneic hematopoietic stem cell recipients who had had more than 1 year of relapse-free survival, regarding time to discontinuation of immunosuppression. Factors such as patient age, donor age, donor sex, immunosuppressive protocols, cell dose, and graft-versus-host-disease (GVHD) were studied. RESULTS: Patients who did not develop GVHD had discontinued immunosuppression according to the protocols, within 1 year for malignant diseases and within 2 years for nonmalignant diseases. Patients given methotrexate as a single drug were off immunosuppression faster than those given cyclosporine alone (P=0.05). Children (<18 years) discontinued immunosuppression faster than adults (P=0.05). Low donor age was of greater importance than low recipient age for early discontinuation (P=0.003). Male recipients of stem cells from immunized female donors needed a longer time to discontinuation (P<0.001). Patients without acute GVHD had a shorter time to discontinuation than patients with any grade of GVHD (P=0.02). Thirteen months after hematopoietic stem cell transplantation, 54% of HLA-identical sibling marrow recipients and 36% of unrelated marrow recipients with malignant disease had discontinued immunosuppression (P=0.002). Twenty-five months after hematopoietic stem cell transplantation, the corresponding figures were 69% and 75% in the two groups, respectively. CONCLUSION: In multivariate analysis, high donor age, immunized female donor to male recipient, and grades II-IV acute GVHD were significantly associated with a longer time to clinical tolerance.

Risk factors for moderate-to-severe chronic graft-versus-host disease after allogeneic hematopoietic stem cell transplantation.

Among 810 consecutive hematopoietic stem cell transplantation (HSCT) patients, 679 survived more than 3 months and were evaluated for chronic GVHD. The aim of this study was to find predisposing factors increasing the risk of development of moderate-to-severe chronic GVHD. Many of the donors were HLA-identical siblings or related (n = 435), 185 were HLA-matched unrelated, and 59 were mismatched related or unrelated donors. Most of the patients had a hematological malignancy (n = 568), but 111 patients with a nonmalignant disease were included. Two hundred twenty-three patients (33%) developed mild, 41 (6%) moderate, and 15 (2.2%) severe chronic GVHD. The 5-year probability of development of moderate-to-severe chronic GVHD was 10%. We analyzed 30 potential risk factors for chronic GVHD. In the multivariate analysis, acute GVHD) grades II to IV (relative hazard [RH], 2.30; 95% CI, 1.29-4.10; P = .005), CML diagnosis (RH, 2.37; CI, 1.38-4.08; P = .002) and transplantation from an immunized female donor to a male recipient (RH, 2.16; CI, 1.14-4.11; P = .02) were independent risk factors for moderate-to-severe chronic GVHD. Recipient age also was significant (RH, 2.42; CI, 1.23-4.77; P = .01) if CML was not included in the analysis. In patients with no risk factors, the 5-year probability of development of moderate-to-severe chronic GVHD was 5%. In patients with 1 risk factor, the probability was 13%; 2 risk factors, 23%; and 3 risk factors, 45%. Among patients who developed chronic GVHD (n = 279), acute GVHD grades II to IV (RH, 2.18; CI, 1.23-3.86; P < .01) was the only predictive factor for moderate-to-severe chronic GVHD versus mild disease. Patients with previous acute GVHD grades II to IV may benefit from more aggressive initial treatment. This possibility would have to be examined in clinical trials.