No abstract

Toxicity associated with a second autologous peripheral blood stem cell transplant (APBSCT) in patients who relapse following initial APBSCT for multiple myeloma (MM) has not been well described. We conducted a retrospective, case-series of 25 consecutive patients who received a second APBSCT for relapsed or progressive disease following prior APBSCT to describe associated toxicity. Grade 3 or 4 toxicities were observed in 92% of patients after each APBSCT. More patients developed an elevated serum creatinine (4%vs. 36%; p = 0.011) following the second APBSCT. Median time to neutrophil engraftment was 10 days following both transplants (p = 0.428). Platelet engraftment was delayed by 2 days after the second APBSCT (median 12 vs.14 days; p < 0.025). There were two deaths before day 100. In conclusion, patients who undergo a second APBSCT for relapsed MM experience more nephrotoxicity. Delayed platelet engraftment and an 8% treatment-related mortality were observed following the second APBSCT.

No abstract

Acute GVHD (aGVHD) is a major cause of morbidity and mortality in hematopoietic allograft recipients. The best therapy for patients failing to respond, or not tolerating, systemic glucocorticoids remains undefined. We evaluated the efficacy of sirolimus in 34 patients, median age of 49 (23-67) years, with steroid-refractory (n=31) or steroid-intolerant (n=3) aGVHD. aGVHD was diagnosed at a median of 34 (7-1042) days post allografting, and confirmed by biopsy in all cases. Initial aGVHD treatment consisted of prednisone up to 2 mg/kg. Sirolimus was initiated at a median of 9 (1-255) days after glucocorticoid initiation. A sirolimus loading dose was administered to 19 (56%) of 34 patients, median 6 (3-8) mg, followed by maintenance of 1-2 mg/day to target therapeutic trough levels between 4 and 12 ng/ml. Overall response rate was 76%. Fifteen (44%) of 34 patients achieved CR, defined as complete resolution of aGVHD sustained for at least 1 month, after sirolimus initiation without additional immunosuppressive agents. CR was achieved in 11 (42%) of 31 steroid-refractory and 2 (67%) of 3 steroid-intolerant patients. Median OS after initiation of sirolimus was 5.6 months, and 1-year OS was 44% (95% CI: 27-60%). Sirolimus is effective in controlling steroid-refractory aGVHD.

Graft-versus-host disease (GvHD) remains a major cause of transplant-related mortality. Interleukin-2 (IL-2) plus sirolimus (SIR) synergistically reduces acute GvHD in rodents and promotes regulatory T cells. This phase II trial tested the hypothesis that IL-2 would facilitate STAT5 phosphorylation in donor T cells, expand regulatory T cells, and ameliorate GvHD. Between 16th April 2014 and 19th December 2015, 20 patients received IL-2 (200,000 IU/m2 thrice weekly, days 0 to +90) with SIR (5–14 ng/mL) and tacrolimus (TAC) (3–7 ng/mL) after HLA-matched related or unrelated allogeneic hematopoietic cell transplantation (HCT). The study was designed to capture an increase in regulatory T cells from 16.0% to more than 23.2% at day +30. IL-2/SIR/TAC significantly increased regulatory T cells at day +30 compared to our published data with SIR/TAC (23.8% vs. 16.0%, P=0.0016; 0.052 k/uL vs. 0.037 k/uL, P=0.0163), achieving the primary study end point. However, adding IL-2 to SIR/TAC led to a fall in regulatory T cells by day +90 and did not reduce acute or chronic GvHD. Patients who discontinued IL-2 before day +100 showed a suggested trend toward less grade II-IV acute GvHD (16.7% vs. 50%, P=0.1475). We surmise that the reported accumulation of IL-2 receptors in circulation over time may neutralize IL-2, lead to progressive loss of regulatory T cells, and offset its clinical efficacy. The amount of phospho-STAT3+ CD4+ T cells correlated with donor T-cell activation and acute GvHD incidence despite early T-cell STAT5 phosphorylation by IL-2. Optimizing IL-2 dosing and overcoming cytokine sequestration by soluble IL-2 receptor may sustain lasting regulatory T cells after transplantation. However, an approach to target STAT3 is needed to enhance GvHD prevention. (clinicaltrials.gov identifier: 01927120).

No abstract

Our previous phase I/II trial of pegylated liposomal doxorubicin (PLD), low-dose dexamethasone, and lenalidomide in patients with relapsed and refractory myeloma showed an overall response rate of 75%, with 29% achieving ≥VGPR. Here, we investigated this combination (PLD 30 or 40 mg/m2 intravenously, day 1; dexamethasone 40 mg orally, days 1-4; lenalidomide 25 mg orally, days 1-21; administered every 28 days) in a phase II study in patients with newly diagnosed symptomatic multiple myeloma to determine its efficacy and tolerability (ClinicalTrials.gov NCT00617591). At best response, patients could proceed with high-dose melphalan or with maintenance lenalidomide and dexamethasone. In 57 patients, we found that the overall response rate and rate of very good partial response and better on intent-to-treat, our primary endpoints, were 77.2% and 42.1%, respectively, with responses per the International Myeloma Working Group. Median progression-free survival was 28 months (95% CI 18.1-34.8), with 1- and 2-year overall survival rates of 98.1 and 79.6%. During induction, grade 3/4 toxicities were neutropenia (49.1%), anemia (15.8%), thrombocytopenia (7%), fatigue (14%), febrile neutropenia (8.8%), and venous thromboembolic events (8.8%). During maintenance, grade 3/4 toxicities were mainly hematologic. We found this combination to be active in patients with newly diagnosed myeloma, with results comparable to other lenalidomide-based induction strategies without proteasome inhibition. In addition, maintenance therapy with lenalidomide was well tolerated.

One limitation of reduced-intensity preparative regimens is potential for graft failure. We have developed a regimen that targets CD4+ lymphodepletion to ensure early and durable engraftment. The primary endpoint was achievement of ≥50% CD3+ donor chimerism by day +28. Forty-two patients (median age, 53 years; range, 29 to 73 years) received pentostatin 4 mg/m2 i.v. on days −28, −21, and −14 when the CD4+ cell count was >100 cells/µL and on days −4 and −3 regardless of CD4+ level. Rituximab 375 mg/m2 was administered to patients with CD20+ malignancies on days −21, −14, −7, +1, and +8. Busulfan 200 mg/m2 i.v. was administered on days −4 and −2 at a dose to target a cumulative AUC dose of 16,000 (−10%) µmol·min/L. Graft-versus-host disease (GVHD) prophylaxis consisted of tacrolimus plus methotrexate in 86% of patients. Donors were matched-related (47%), matched unrelated (43%), or mismatched unrelated (10%). Chronic lymphocytic leukemia (45%) and follicular non-Hodgkin lymphoma (14%) were the most common diagnoses. Disease status at initiation of the preparative regimen was complete remission in 22%, partial response in 55%, and stable/progression in 24%. The median percent CD4+ cell count decrease from baseline (day −28) was 52% to day −21, 66% to day −14, 62% to day −7, and 91% to day 0. At day +28, all 42 patients (100%) had ≥50% CD3+ donor chimerism. No patient experienced graft failure. Overall response rate was 82% (complete remisson, 67%). The day +100 cumulative incidence of grade II–IV acute GVHD was 59% (grade III-IV acute GVHD, 19%), and the 2 year cumulative incidence of chronic GVHD was 69% (moderate/severe, 58%). Non-relapse mortality was 2% at day +100 and 17% at 2 years. Two-year PFS was 55%, and OS was 68%. This regimen ensures durable engraftment, is effective against persistent disease, and results in relatively low mortality from causes other than relapse.