Gemcitabine and vinorelbine combination is effective in both as a salvage and mobilization regimen in relapsed or refractory Hodgkin lymphoma prior to ASCT

Outcome and toxicity of ifosfamide, carboplatin, and etoposide versus gemcitabine and vinorelbine regimen for pediatric patients with relapsed or refractory Hodgkin's lymphoma

Background

Pediatric classical Hodgkin lymphoma (CHL) is a curable disease; however, the optimal salvage regimen is unclear for relapsed/refractory (R/R) disease. This study aimed to compare response rates, toxicity, event-free survival (EFS), and overall survival (OS) of ifosfamide, carboplatin, and etoposide (ICE) with gemcitabine and vinorelbine (GV) regimen after first-line doxorubicin, bleomycin, vinblastine, dacarbazine (ABVD) in pediatric patients with R/R CHL.

Methods

This is a retrospective cohort study of 132 pediatric patients with R/R CHL treated from July 2012 to December 2020 with ICE (n = 82) or GV (n = 50).

Results

The median age at relapse was 13.9 years, and 68.2% were men. Rates of complete response, partial response, and progressive disease before consolidation were 50.6%, 3.7%, and 45.7% for ICE and 28.5%, 0%, and 71.5% for GV (P = 0.011). By multivariate analysis, regimen (P = 0.002), time to relapse (P = 0.0001), and B-symptoms (P = 0.002) were independent factors to lower response rates. Hematological toxicity, electrolyte disturbance, hemorrhagic cystitis, infectious complications, and hospital admission for fever neutropenia were statistically significant higher for the ICE regimen. Treatment-related mortalities were 2.4% for ICE and 2% for GV (P = 0.86). The 3-year EFS was 39.3% ± 11.4% for ICE and 24.9% ± 12.5% for GV (P = 0.0001), while 3-year OS was 69.3% ± 10.6% and 74% ± 12.9% (P = 0.3), respectively. By multivariate analysis, regimen (P = 0.0001), time to relapse (P = 0.011), B-symptoms (P = 0.001), and leukocytosis (P = 0.007) were significant for EFS, while anemia (P = 0.008), and progressive disease on early response evaluation (P = 0.022) were significant for OS.

Conclusions

The ICE regimen had a better overall response rate and EFS, but higher toxicity, than GV; however, OS and mortality were similar.

Ecofriendly LC-MS/MS and TLC-densitometric methods for simultaneous quantitative assay and monitoring of BEGEV regimen, in vivo pharmacokinetic study application

To date no analytical method has been developed for the determination of the BEGEV regimen and no study has investigated the kinetic interaction between the drugs, to give us priorities for further clinical study, so two rapid, accurate, sensitive and ecofriendly chromatographic methods were developed for the simultaneous determination of bendamustine (BEN), gemcitabine (GEM) and vinorelbine (VIB) using sildenafil (SIL) as an internal standard (IS) for the purpose of an in vivo pharmacokinetics study in rats. Firstly, the LC-MS/MS method was performed using a mixture of methanol and a 0.1% aqueous solution of formic acid as the mobile phase on a ZORBAX Eclipse Plus C₁₈ (4.6 mm × 150 mm, 5 μm) column as the stationary phase. BEN, GEM and VIB were ionized by positive ions and detected in the multi-reaction monitoring (MRM) mode using precursor → products of m/z 358.20 → 228.25 for BEN, m/z 264.05 → 112.15 for GEM, m/z 779.55 → 122.20 for VIB and m/z 475.00 → 58.35 for SIL. Secondly, TLC-densitometry was applied on TLC silica gel plates using methanol : ethyl acetate (8 : 2, v/v) as the developing system when the separated peaks were scanned at 280 nm. FDA guidelines were followed for validation of the proposed methods, which presented acceptable ranges; then they were applied for an in vivo study in rats with a quantitative determination of each drug after single or combined administration for an investigation of any suspected drug-drug interaction, and all pharmacokinetic parameters were calculated for therapeutic drug monitoring of those drugs. Green analytical chemistry principles were considered during all the procedural steps to ensure the greenness and the safety of the methods, which were evaluated using four assessment tools, eco-scale assessment, the national environmental method index (NEMI), the green analytical procedure index (GAPI) and the analytical greenness metric approach (AGREE), and the results were satisfactory.

Gemcitabine, Cisplatin, and Dexamethasone as a Salvage and Mobilization Chemotherapy Before Autologous Stem Cell Transplantation is Effective and Safe Outpatient Regimen in Relapsed and Refractory Hodgkin Lymphoma Patients

BACKGROUND

Second line salvage chemotherapy followed by autologous stem cell transplantation (ASCT) is the current standard treatment for eligible patients with relapsed and refractory (R/R) Hodgkin lymphoma (HL). Several salvage regimens have been used before ASCT. However the optimal salvage regimen is still unclear. We report outcome of patients with R/R HL treated with gemcitabine, cisplatin, and dexamethasone (GDP) regimen before ASCT in this retrospective study aiming at evaluating efficacy, stem cell mobilization activity and safety of GDP in a real-life setting.

PATIENTS AND METHODS

Forty-five patients with R/R HL who were treated with GDP as salvage and mobilization regimen before ASCT were analyzed retrospectively. Peripheral blood stem cells (PBSC) were collected after GDP. All patients underwent ASCT after 2 cycles of GDP.

RESULTS

Thirty-six (80%) patients achieved overall response including 24 (53.3%) complete response (CR). PBSC collections were adequate in all patients with a median number of 11.01 × 10⁶/kg CD34+ cells. The most common grade 3/4 hematological adverse events were thrombocytopenia (31.1%) and neutropenia (22.2%). There were no febrile neutropenic episodes. Grade 3 or 4 renal, hepatic, or cardiac toxicity was not observed. The 4 year progression-free survival and overall survival for patients receiving GDP followed by ASCT were 72% and 92%, respectively.

CONCLUSION

Our results suggest that GDP is a viable therapeutic option before ASCT with high response rate, favorable toxicity profile and excellent mobilization potential. Applicability of GDP on an outpatient setting also provides advantage over other effective salvage regimens.

High efficacy of BGD (bendamustine, gemcitabine, and dexamethasone) in relapsed/refractory Hodgkin Lymphoma

The optimal salvage therapy in relapsed/refractory Hodgkin lymphoma (R/R HL) has not been defined so far. The goal of this multicenter retrospective study was to evaluate efficacy and safety of BGD (bendamustine, gemcitabine, dexamethasone) as a second or subsequent line of therapy in classical R/R HL. We have evaluated 92 consecutive R/R HL patients treated with BGD. Median age was 34.5 (19-82) years. Fifty-eight patients (63%) had received 2 or more lines of chemotherapy, 32 patients (34.8%) radiotherapy, and 21 patients (22.8%) an autologous hematopoietic stem cell transplantation (autoHCT). Forty-four patients (47.8%) were resistant to first line of chemotherapy. BGD therapy consisted of bendamustine 90 mg/m² on days 1 and 2, gemcitabine 800 mg/m² on days 1 and 4, dexamethasone 40 mg on days 1-4. Median number of BGD cycles was 4 (2-7). The following adverse events ≥ 3 grade were noted: neutropenia (22.8%), thrombocytopenia (20.7%), anemia (15.2%), infections (10.9%), AST/ALT increase (2.2%), and skin rush (1.1%). After BGD therapy, 51 (55.4%) patients achieved complete remission, 23 (25%)-partial response, 7 (7.6%)-stable disease, and 11 (12%) patients experienced progression disease. AutoHCT was conducted in 42 (45.7%) patients after BGD therapy, and allogeneic HCT (alloHCT) in 16 (17.4%) patients. Median progression-free survival was 21 months. BGD is a highly effective, well-tolerated salvage regimen for patients with R/R HL, providing an excellent bridge to auto- or alloHCT.

Ifosfamide, gemcitabine, and vinorelbine is an effective salvage regimen with excellent stem cell mobilization in relapsed or refractory pediatric Hodgkin lymphoma

We describe 12 pediatric patients (8-16 years) with primary refractory (N = 6) or first relapse (N = 6) Hodgkin lymphoma (HL) treated with ifosfamide, gemcitabine, and vinorelbine (IGEV). The overall response rate to IGEV was 100%, with seven (58%) complete responses (CR) and five (42%) partial responses. Successful CD34⁺ stem cell mobilization was achieved in all patients. Following subsequent autologous stem cell transplantation, 10 patients (83%) achieved CR. At a median follow-up of 71 months, 11 patients had no evidence of disease. Five-year second event-free survival and overall survival were 83% ± 11.0% and 90.0% ± 9.5%, respectively. IGEV is an effective salvage regimen for children with relapsed/refractory HL.

Gemcitabine and bendamustine is a safe and effective salvage regimen for patients with recurrent/refractory Hodgkin lymphoma: Results of a phase 1/2 study

BACKGROUND

Both gemcitabine and bendamustine have been evaluated in patients with recurrent/refractory Hodgkin lymphoma but to the authors' knowledge not as a doublet. The authors completed a phase 1/2 trial to identify the optimal dose and frequency of administration and to assess the efficacy of this combination in patients with recurrent/refractory Hodgkin lymphoma.

METHODS

Patients were treated up to a maximum dose of gemcitabine (1000 mg/m² on day 1) and bendamustine (120 mg/m² on days 1 and 2), which was determined to be the recommended phase 2 dose, administered every 21 days for up to 6 cycles. Patients could discontinue study therapy after 2 cycles to proceed with autologous or allogeneic stem cell transplantation.

RESULTS

No dose-limiting toxicities were identified, but 4 patients experienced grade 3 to 5 pulmonary adverse events (toxicity was graded according to Common Terminology Criteria for Adverse Events [version 4]). A total of 26 patients were enrolled having completed a median of 4 prior lines of therapy (range, 1-7 lines), including 13 patients at the recommended phase 2 dose, in whom the overall response rate was 69% and the complete response rate was 46%. The median progression-free survival for the phase 2 patients was 11 months (95% CI, 3 months to not reached), and the median overall survival for this group had not been reached at the time of last follow-up (95% CI, 4 months to not reached).

CONCLUSIONS

This doublet was found to be tolerable and effective, but patients must be monitored closely for pulmonary toxicity. The authors currently are evaluating this doublet in combination with nivolumab.

Advances in the pathophysiology and treatment of relapsed/refractory Hodgkin's lymphoma with an emphasis on targeted therapies and transplantation strategies

Hodgkin’s lymphoma (HL) is highly curable with first-line therapy. However, a minority of patients present with refractory disease or experience relapse after completion of frontline treatment. These patients are treated with salvage chemotherapy followed by autologous stem cell transplantation (ASCT), which remains the standard of care with curative potential for refractory or relapsed HL. Nevertheless, a significant percentage of such patients will progress after ASCT, and allogeneic hematopoietic stem cell transplantation remains the only curative approach in that setting. Recent advances in the pathophysiology of refractory or relapsed HL have provided the rationale for the development of novel targeted therapies with potent anti-HL activity and favorable toxicity profile, in contrast to cytotoxic chemotherapy. Brentuximab vedotin and programmed cell death-1-based immunotherapy have proven efficacy in the management of refractory or relapsed HL, whereas several other agents have shown promise in early clinical trials. Several of these agents are being incorporated with transplantation strategies in order to improve the outcomes of refractory or relapsed HL. In this review we summarize the current knowledge regarding the mechanisms responsible for the development of refractory/relapsed HL and the outcomes with current treatment strategies, with an emphasis on targeted therapies and hematopoietic stem cell transplantation.

Clinical effects of vinorelbine administration in the management of various malignant tumor types in dogs: 58 cases (1997-2012)

OBJECTIVE

To evaluate the effectiveness of vinorelbine in the management of various malignant tumor types in dogs.

DESIGN

Retrospective case series.

ANIMALS

58 dogs with malignant tumors, including pulmonary carcinoma (n = 31), histiocytic sarcoma (9), mast cell tumor (5), lymphoma (4), melanoma (2), and 7 other tumor types (1 each).

PROCEDURES

Medical records of dogs treated with vinorelbine from December 1997 to December 2012 were reviewed for data regarding signalment, clinical signs, physical examination findings, clinicopathologic test results, diagnostic imaging results, vinorelbine doses and dose frequency, surgery and radiotherapy details when applicable, other chemotherapeutics administered, and outcomes. Descriptive, comparative, and survival statistics were computed for all dogs and for dogs by histologic subgroup of tumors.

RESULTS

Vinorelbine was administered palliatively to 44 (76%) dogs. One (2%) dog had a complete response for 162 days, 5 (11%) dogs had a partial response for a median duration of 91 days, 19 (43%) dogs had stable disease for a median duration of 68 days, and 19 (43%) dogs developed progressive disease after a median duration of 21 days. Clinical benefit was more difficult to assess in the remaining 14 (24%) dogs that received vinorelbine as an adjuvant treatment. Overall median time to tumor progression was 103 days (range, 5 to 1,533 days).

CONCLUSIONS AND CLINICAL RELEVANCE

Vinorelbine appeared to be effective in the treatment of several tumor types in dogs. Follow-up prospective studies of the clinical benefit of the drug in specific clinical scenarios will be necessary to support this conclusion.

Role of cytotoxic therapy with hematopoietic cell transplantation in the treatment of Hodgkin lymphoma: guidelines from the American Society for Blood and Marrow Transplantation

The role of hematopoietic cell transplantation (HCT) in the therapy of Hodgkin lymphoma (HL) in pediatric and adult patients is reviewed and critically evaluated in this systematic evidence-based review. Specific criteria were used for searching the published literature and for grading the quality and strength of the evidence and the strength of the treatment recommendations. Treatment recommendations based on the evidence are included and were reached unanimously by a panel of HL experts. Both autologous and allogeneic HCT offer a survival benefit in selected patients with advanced or relapsed HL and are currently part of standard clinical care. Relapse remains a significant cause of failure after both transplant approaches, and strategies to decrease the risk of relapse remain an important area of investigation.

Stem cell transplantation in Hodgkin lymphoma

Patients with Hodgkin lymphoma (HL) who relapse following effective front-line therapy are offered salvage second-line chemotherapy regimens followed by high-dose therapy and autologous stem cell transplantation (HDT/ASCT). Randomized studies comparing HDT/ASCT with conventional chemotherapy in patients with relapsed refractory HL have shown significant improvement in progression-free survival and freedom from treatment failure but were not powered to show improvements in overall survival. For patients who relapse after salvage HDT/ASCT, novel therapies exist as a bridge to allogeneic SCT. In this article, we review indications and results of autologous and allogeneic SCT in HL.

Gemcitabine and Vinorelbine (GemVin) Regimen

The complexity of cancer chemotherapy requires pharmacists be familiar with the complicated regimens and highly toxic agents used. This column reviews various issues related to preparation, dispensing, and administration of antineoplastic therapy, and the agents, both commercially available and investigational, used to treat malignant diseases. Questions or suggestions for topics should be addressed to Dominic A. Solimando, Jr, President, Oncology Pharmacy Services, Inc., 4201 Wilson Blvd #110-545, Arlington, VA 22203, e-mail: OncRxSvc@comcast.net; or J. Aubrey Waddell, Professor, University of Tennessee College of Pharmacy; Oncology Pharmacist, Pharmacy Department, Blount Memorial Hospital, 907 E. Lamar Alexander Parkway, Maryville, TN 37804, e-mail: waddfour@charter.net.

GEM-P chemotherapy is active in the treatment of relapsed Hodgkin lymphoma

Hodgkin lymphoma (HL) is a relatively chemosensitive malignancy. However, for those who relapse, high-dose chemotherapy with autologous stem cell transplant is the treatment of choice which relies on adequate disease control with salvage chemotherapy. Regimens commonly used often require inpatient administration and can be difficult to deliver due to toxicity. Gemcitabine and cisplatin have activity in HL, non-overlapping toxicity with first-line chemotherapeutics, and may be delivered in an outpatient setting. In this retrospective single-centre analysis, patients with relapsed or refractory HL treated with gemcitabine 1,000 mg/m(2) day (D)1, D8 and D15; methylprednisolone 1,000 mg D1-5; and cisplatin 100 mg/m(2) D15, every 28 days (GEM-P) were included. Demographic, survival, response and toxicity data were recorded. Forty-one eligible patients were identified: median age 27. One hundred and twenty-two cycles of GEM-P were administered in total (median 3 cycles; range 1-6). Twenty of 41 (48 %) patients received GEM-P as second-line treatment and 11/41 (27 %) as third-line therapy. Overall response rate (ORR) to GEM-P in the entire cohort was 80 % (complete response (CR) 37 %, partial response 44 %) with 14/15 CR confirmed as a metabolic CR on PET and ORR of 85 % in the 20 second-line patients. The most common grade 3/4 toxicities were haematological: neutropenia 54 % and thrombocytopenia 51 %. Median follow-up from the start of GEM-P was 4.5 years. Following GEM-P, 5-year progression-free survival was 46 % (95 % confidence interval (CI), 30-62 %) and 5-year overall survival was 59 % (95 % CI, 43-74 %). Fourteen of 41 patients proceeded directly to autologous transplant. GEM-P is a salvage chemotherapy with relatively high response rates, leading to successful transplantation in appropriate patients, in the treatment of relapsed or refractory HL.

Phase I clinical trial of vinorelbine in tumor-bearing cats

BACKGROUND

Vinorelbine (VRL) has been investigated in dogs, but its use in cats has not been studied.

HYPOTHESIS/OBJECTIVES

To determine the maximal tolerated dose (MTD) and dose-limiting toxicity (DLT) of VRL in tumor-bearing cats.

ANIMALS

Cats were included in this prospective phase I trial if they had confirmed malignancy, received ≥1 VRL treatment, and had adequate follow-up. Previous treatment was acceptable, but concurrent chemotherapy or radiotherapy was not permitted.

METHODS

Using a modified phase I design, cats were enrolled in cohorts of 3 at a starting dosage of 9 mg/m(2) . Cats tolerating the first treatment well were eligible to receive additional VRL treatments at escalating dosages; escalations beyond the perceived MTD were permitted based on individual tolerance. Intended treatment interval was 7 days. Patient histories, physical examinations, and complete blood counts were performed weekly.

RESULTS

Nineteen cats were included. Sixty-one VRL treatments were administered. Median number of treatments was 2 (range, 1-9). Starting dosages were 9-12 mg/m(2) . Maximal dosage administered was 15.5 mg/m(2) . The MTD was 11.5 mg/m(2) . Acute DLTs were neutropenia, vomiting, and nephrotoxicity. Other notable toxicities were weight loss and anemia.

CONCLUSIONS AND CLINICAL IMPORTANCE

Vinorelbine is tolerated in cats at a weekly interval. Recommended starting dosage is 11.5 mg/m(2) . Neutropenia was transient, lasting <7 days; vomiting was self-limiting in most cases. Although VRL-associated nephrotoxicity has not been reported, potential attribution of this toxicity to VRL must not be discounted. Further investigation of the efficacy of VRL in feline malignancies is warranted.

Which regimen is better for stem cell mobilization of lymphoma patients?

Although chemotherapy combined with G-CSF is an effective method for hematopoietic stem cell mobilization, standard chemotherapy protocol leading to best stem cell yield is not defined. In our study, we aimed to assess the impact of chemotherapy choice on mobilization outcome in lymphoma patients. Patients were mobilized with cyclophosphamide (n:15), ASHAP (n:11) or VGEPP (n:12) protocols. Groups were similar according to collected CD34+ cell count, total nucleated cell count and median apheresis days. Five out of fifteen (33%) patients could not be mobilized in Cy group but there was only one failed mobilization attempt in both salvage groups (9% with ASHAP vs 8% with VGEPP). In conclusion, we showed that VGEPP and ASHAP are safe protocols in terms of stem cell mobilization and have similar mobilization capacity as cyclophosphamide alone.

Outcome of autologous stem-cell transplantation in relapsed or refractory Hodgkin lymphoma patients in a centre from Turkey

PURPOSE

The aim of this study is to assess the predictors of outcome in patients with relapsed or refractory Hodgkin's lymphoma (HL) receiving autologous stem-cell transplantation (ASCT) MATERIALS AND METHODS: Fifty-two consecutive patients who received ASCT at the Stem Cell Transplantation Unit of Gazi University Hospital from February 2005 through June 2011 for relapsed or refractory HL were analysed retrospectively

RESULTS

Fifty-one patients could be evaluated after transplantation, as one of the patients died in the early post-transplantation period. Complete remission was obtained in 36 (71%), partial remission in 9 (18%), stable disease in 4 (8%), and progressive disease in 2 (3%) patients. After a median follow-up of 22 (range, 0.5-75) months, 46 (88%) patients were alive. The probability of overall survival (OS), progression free survival (PFS) and transplantation related mortality at 5 years were 87, 53, and 2%, respectively. Chemosensitive relapse had a positive impact on both OS and PFS CONCLUSION: ASCT remains to be the standard treatment of relapsed or refractory HL patients. Chemosensitive relapse is the most important prognostic factor determining the outcome of the ASCT.

Epigenetic modifiers enhance the synergistic cytotoxicity of combined nucleoside analog-DNA alkylating agents in lymphoma cell lines

Hematopoietic stem cell transplantation is used for treatment of lymphoma. In an attempt to design an efficacious and safe prehematopoietic stem cell transplantation conditioning regimen, we investigated the cytotoxicity of the combination of busulfan (B), melphalan (M), and gemcitabine (G) in lymphoma cell lines in the absence or presence of drugs that induce epigenetic changes. Cells were exposed to drugs individually or in combination and analyzed by the MTT proliferation assay, flow cytometry, and Western blotting. We used ~IC(10) drug concentrations (57 μM B, 1 μM M and 0.02 μM G), which individually did not have major effects on cell proliferation. Their combination resulted in 50% inhibition of proliferation. Reduction to almost half concentration (20 μM B, 0.7 μM M and 0.01 μM G) did not have significant effects, but addition of the histone deacetylase inhibitor suberoylanilide hydroxamic acid (0.6 μM) to this combination resulted in a marked (~65%) growth inhibition. The cytotoxicity of these combinations correlates with the activation of the ataxia telangiectasia mutated-CHK2 pathway, phosphorylation of KRAB-associated protein-1, epigenetic changes such as methylation and acetylation of histone 3, and activation of apoptosis. The relevance of epigenetic changes is further shown by the induction of DNA methyltransferases in tumor cells with low constitutive levels of DNMT3A and DNMT3B. The addition of 5-aza-2'-deoxycytidine to (BMG+suberoylanilide hydroxamic acid) further enhances cell killing. Overall, BMG combinations are synergistically cytotoxic to lymphoma cells. Epigenetic changes induced by suberoylanilide hydroxamic acid and 5-aza-2'-deoxycytidine further enhance the cytotoxicity. This study provides a rationale for an ongoing clinical trial in our institution using (BMG+suberoylanilide hydroxamic acid) as pre-hematopoietic stem cell transplantation conditioning for lymphoma.

Current status of autologous stem cell transplantation in relapsed and refractory Hodgkin's lymphoma

Despite the relatively high long-term disease-free survival (DFS) rate for patients with Hodgkin lymphoma (HL) with modern combination chemotherapy or combined modality regimens, ∼20% of patients die from progressive or relapsed disease. The standard treatment for relapsed and primary refractory HL is salvage chemotherapy followed by high-dose chemotherapy and autologous stem cell transplantation (ASCT), which has shown a 5-year progression-free survival rate of ∼50%-60%. Recent developments in a number of diagnostic and therapeutic modalities have begun to improve these results. Functional imaging, refinement of clinical prognostic factors, and development of novel biomarkers have improved the predictive algorithms, allowing better patient selection and timing for ASCT. In addition, these algorithms have begun to identify a group of patients who are candidates for more aggressive treatment beyond standard ASCT. Novel salvage regimens may potentially improve the rate of complete remission prior to ASCT, and the use of maintenance therapy after ASCT has become a subject of current investigation. We present a summary of developments in each of these areas.

Synergistic cytotoxicity of the DNA alkylating agent busulfan, nucleoside analogs and suberoylanilide hydroxamic acid in lymphoma cell lines

Hematopoietic stem cell transplant (HSCT) is a promising treatment for lymphomas. Its success depends on effective pre-transplant conditioning regimens. We previously reported on the efficacy of DNA alkylating agent-nucleoside analog (NA) combinations for conditioning in acute myeloid leukemia (AML). We hypothesized that a similar combinatory approach can be used for lymphomas. A combination of busulfan (Bu) with two NAs - clofarabine (Clo), fludarabine (Flu) or gemcitabine (Gem) - resulted in synergistic cytotoxicity in lymphoma cell lines. We demonstrated that the [2 NAs + Bu] combination activates a DNA damage response through the ATM-CHK2 and ATM-CHK1 pathways, leading to cell cycle checkpoint activation and apoptosis. Histone modifications and KAP1 phosphorylation are indicative of chromatin relaxation mediated by the nucleoside analogs, which sequentially increase Bu alkylation. Addition of suberoylanilide hydroxamic acid (SAHA) enhanced chromatin relaxation through increased histone acetylation and further augmented the cytotoxicity of [2 NAs + Bu]. Our results provide a preclinical basis for a clinical trial on using [2 NAs + Bu ± SAHA] combinations as conditioning therapy for patients with chemotherapy-refractory lymphoma undergoing HSCT.