Allogeneic stem cell transplantation in patients with mantle cell lymphoma: results from the MANTLE-FIRST study on behalf of Fondazione Italiana Linfomi

The role of allogeneic stem cell transplantation (allo-SCT) in mantle cell lymphoma (MCL) is uncertain, even more in the era of bruton's tyrosine kinase inhibitors (BTKi) and chimeric antigen receptor T-cells. We retrospectively analyzed 55 patients who underwent allo-SCT for MCL relapsed or refractory (r/r) after rituximab and high-dose cytarabine within the MANTLE-FIRST project. With a median follow-up of 3.7 years, non-relapse mortality (NRM), progression-free survival, and overall survival were 23%, 53%, and 56%, respectively. NRM was significantly higher in the case of acute graft-versus-host disease, > 2 prior lines of therapy, age > 60 years. The outcome was similar for patients with early (≤24 months) and late progression of disease. The use of BTKi as a bridge to allo-SCT did not increase the toxicity and allowed a good control of disease. Our real-life experience confirms that allo-SCT still represents an option in MCL patients, especially if young and early-relapsed.

Efficacy of idelalisib and rituximab in relapsed/refractory chronic lymphocytic leukemia treated outside of clinical trials. A report of the Gimema Working Group

Because the efficacy of new drugs reported in trials may not translate into similar results when used in the real‐life, we analyzed the efficacy of idelalisib and rituximab (IR) in 149 patients with relapsed/refractory chronic lymphocytic leukemia treated at 34 GIMEMA centers. Median progression‐free survival (PFS) and overall survival were 22.9 and 44.5 months, respectively; performance status (PS) ≥2 and ≥3 previous lines of therapy were associated with shorter PFS and overall survival (OS). 48% of patients were on treatment at 12 months; the experience of the centers (≥5 treated patients) and PS 0–1 were associated with a significantly longer treatment duration (p = 0.015 and p = 0.002, respectively). TP53 disruption had no prognostic significance. The overall response rate to subsequent treatment was 49.2%, with median OS of 15.5 months and not reached in patients who discontinued, respectively, for progression and for toxicity (p < 0.01). Treatment breaks ≥14 days were recorded in 96% of patients and adverse events mirrored those reported in trials. In conclusion, this real‐life analysis showed that IR treatment duration was longer at experienced centers, that the ECOG PS and ≥3 lines of previous therapy are strong prognostic factor and that the overall outcome with this regimen was superimposable to that reported in a randomized trial.

ROBUST: A Phase III Study of Lenalidomide Plus R-CHOP Versus Placebo Plus R-CHOP in Previously Untreated Patients With ABC-Type Diffuse Large B-Cell Lymphoma

Patients with the activated B-cell-like (ABC) subtype of diffuse large B-cell lymphoma (DLBCL) historically showed inferior survival with standard rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). Phase II studies demonstrated that adding the immunomodulatory agent lenalidomide to R-CHOP improved outcomes in ABC-type DLBCL. The goal of the global, phase III ROBUST study was to compare lenalidomide plus R-CHOP (R2-CHOP) with placebo/R-CHOP in previously untreated, ABC-type DLBCL.

Applying Data Warehousing to a Phase III Clinical Trial From the Fondazione Italiana Linfomi Ensures Superior Data Quality and Improved Assessment of Clinical Outcomes

PURPOSE

Data collection in clinical trials is becoming complex, with a huge number of variables that need to be recorded, verified, and analyzed to effectively measure clinical outcomes. In this study, we used data warehouse (DW) concepts to achieve this goal. A DW was developed to accommodate data from a large clinical trial, including all the characteristics collected. We present the results related to baseline variables with the following objectives: developing a data quality (DQ) control strategy and improving outcome analysis according to the clinical trial primary end points.

METHODS

Data were retrieved from the electronic case reporting forms (eCRFs) of the phase III, multicenter MCL0208 trial (ClinicalTrials.gov identifier: NCT02354313) of the Fondazione Italiana Linfomi for younger patients with untreated mantle cell lymphoma (MCL). The DW was created with a relational database management system. Recommended DQ dimensions were observed to monitor the activity of each site to handle DQ management during patient follow-up. The DQ management was applied to clinically relevant parameters that predicted progression-free survival to assess its impact.

RESULTS

The DW encompassed 16 tables, which included 226 variables for 300 patients and 199,500 items of data. The tool allowed cross-comparison analysis and detected some incongruities in eCRFs, prompting queries to clinical centers. This had an impact on clinical end points, as the DQ control strategy was able to improve the prognostic stratification according to single parameters, such as tumor infiltration by flow cytometry, and even using established prognosticators, such as the MCL International Prognostic Index.

CONCLUSION

The DW is a powerful tool to organize results from large phase III clinical trials and to effectively improve DQ through the application of effective engineered tools.

The classic prognostic factors in advanced Hodgkin's lymphoma patients are losing their meaning at the time of Pet-guided treatments

The International Prognostic Score (IPS) is the most commonly used risk stratification tool for patients with advanced Hodgkin lymphoma (HL). It incorporates seven clinical parameters independently associated with a poorer outcome: male sex, age, stage IV, hemoglobin level, white blood cell and lymphocyte counts, and albumin level. Since the development of the IPS, there have been significant advances in therapy and supportive care. Recent studies suggest that the IPS is less discriminating due to improved outcomes with ABVD therapy. The aim of the present study was to asses if classic prognostic factors maintain their prognostic meaning at the time of response-adapted treatment based on interim PET scans. We evaluated the prognostic significance of IPS in the 520 advanced stage HL patients enrolled in the PET-guided, HD0801 trial in which PET2-positive patients underwent a more intense treatment with an early stem-cell transplantation after 2 cycles of ABVD. We observed that in these patients, the IPS completely loses its prognostic value together with all the single parameters that contribute to the IPS. Furthermore, neutrophils, monocytes, lymphocytes, and the ratio among them also no longer had any predictive value. We believe that the substantial improvement in survival outcomes in PET2-positive patients treated with early autologous transplantation could explain the complete disappearance of the residual prognostic significance of the IPS.

Obinutuzumab and miniCHOP for unfit patients with diffuse large B-cell lymphoma. A phase II study by Fondazione Italiana Linfomi

OBJECTIVE

To evaluate activity and safety of obinutuzumab-miniCHOP (Ga101-miniCHOP) combination in older patients with Diffuse Large B-Cell Lymphoma (DLBCL) unfit to receive full dose immunochemotherapy.

MATERIALS AND METHODS

We conducted a Simon's two-stage phase II multicenter trial to investigate response rate (primary endpoint) and safety of six courses of Ga101-miniCHOP in older patients with DLBCL (≥65 years), prospectively defined as unfit according to a simplified Comprehensive Geriatric Assessment (sCGA).

RESULTS

Overall, 34 patients were enrolled (median age 82 years; range 68-89), with 27 out of the 33 eligible patients completing all six planned courses. Complete Remission (CR) rate was reported in fourteen patients (42%). After a median follow-up of sixteen months, the two-year Progression Free and Overall Survival (PFS and OS) were 49% (95% Confidence Interval (CI), 28 to 67) and 68% (95% CI, 49 to 81), respectively. The most frequent grade 3-4 adverse event was neutropenia in thirteen patients (26%).

CONCLUSIONS

Based on the observed CR rate, study accrual was interrupted due to the very low probability of demonstrating the initial study hypothesis that Ga101-miniCHOP could improve results of historical data obtained with R-miniCHOP in this group of patients. Nonetheless, results achieved with the 33 treated patients confirm activity and good tolerability of the Ga101-miniCHOP regimen for older unfit adult patients with DLBCL.

Cyclophosphamide, Methotrexate, 5-Fluorouracil, Alternating with Adriamycin and Mitomycin C in Metastatic Breast Cancer: A Pilot Study

To explore the clinical applicability of the Goldie and Coldman hypothesis, we treated 28 patients with metastatic breast cancer with alternating non-cross-resistant chemotherapy. The patients received cyclophosphamide, 600 mg/m2, 5-fluorouracil, 600 mg/m2, methotrexate, 40 mg/m3, alternated every three weeks with adriamycin, 60 mg/m2, and mitomycin C, 10 mg/m2. Only one patient had previously received palliative chemotherapy. Six patients had received adjuvant CMF, and 17 patients had been pretreated with endocrine therapy (13 for advanced disease, 4 as adjuvant). Fourteen patients had bone involvement, and 10 had visceral metastases. A mean of 12 cycles was given to 24 evaluable patients. The objective response rate was 67%: 11 patients (46%) achieved complete and 5 (21%) partial remission. Response rate in soft tissues was 83.3%, in bone 50%, in liver 100%, and in lung 80%. The median duration of response was 14 months, with 7 patients still in remission. No life-threatening toxicity was observed. Our preliminary results support the validity of this approach and the efficacy of this combination chemotherapy. A large-scale randomized study is warranted.

Applicability of Local Hyperthermia as Adjuvant to Systemic Chemotherapy

With the aim of verifying the in vivo applicability of local hyperthermia combined with chemotherapy, 13 patients with superficial metastases from different histologic types of carcinoma, mostly from head and neck cancer, were entered in a pilot study. The chemotherapeutic regimen was cisplatinum, 20 mg/m2/dx5 days, bleomycin, 10 mg/m2 on days 8 and 12, methotrexate, 100 mg/m2 on day 15, followed after 24 by folinic acid. Hyperthermia, using a microwave apparatus, and chemotherapy were delivered simultaneously. Objective remissions were achieved in 54% of patients, within the hyperthermia field (1 CR and 6 PR). No serious toxicity was noted. Methotrexate distribution after local hyperthermia was evaluated in 8 patients. Response duration was not gratifying, except for patients successively treated with radiation. In conclusion, the combination of chemotherapy plus local hyperthermia deserves subsequent evaluation as part of adjunctive programs.

Effectiveness of Fludarabine, Idarubicin and Cyclophosphamide (FLUIC) Combination Regimen for Young Patients with Untreated Non-Follicular Low-Grade Non-Hodgkin's Lymphoma

In the last years, fludarabine (FLU) alone or in combination with other drugs has been reported to be effective in the treatment of previously untreated low-grade non-Hodgkin's lymphomas (LG-NHL). We report on the therapeutic efficacy and toxicity of a combination of FLU, idarubicin and cyclophosphamide (FLUIC regimen) in untreated non-follicular LG-NHL. We administered a three-drug combination of FLU (25 mg/m2 i.v. on days 1 to 3), idarubicin (14 mg/m2 i.v. on day 1) and cyclophosphamide (200 mg/m2 i.v. on days 1 to 3) to treat 41 young, previously untreated patients with non-follicular LG-NHL. Chemotherapy was repeated every 4 weeks for a total of 6 cycles. Among 41 patients, 24 (59%) were diagnosed with small lymphocytic, 10 (24%) with immnocytoma, and 7 (17%) with marginal zone subtypes. Nineteen (46%) patients achieved complete response (CR) and 21 (51%) partial response, while the remaining 1 (3%) showed no benefit from the treatment. With respect to histology, we observed CR rates of 38% for the small lymphocytic subtype, 40% for the immunocytoma subtype, and 86% for the marginal zone subtype. Estimated 42-month overall survival and relapse-free survival rates were 64% and 100%, respectively. Hematologic grade 3-4 toxicity was seen in 9 (22%) patients; no opportunistic infection or death was associated with administration of the FLUIC regimen. These preliminary data suggest that FLUIC is a very active, well-tolerated regimen for young, untreated patients with advanced non-follicular LG-NHL.

Role of anemia in survival of patients with elderly aggressive non-Hodgkin's lymphoma after chemotherapy

Baseline anemia is a relevant prognostic factor in the overall population of non-Hodgkin's lymphoma (NHL) patients, and studies focusing on elderly NHL are awaited. We conducted a pooled analysis of a cohort of comparable patients enrolled (1993 - 2001) in three multicenter clinical trials on use of a MACOP-B-like regimen (VNCOP-B) for front-line treatment of elderly aggressive NHL. Models of Cox's proportional hazards regression analysis of prognostic value of pre-/post-treatment hemoglobin values in terms of 5-year overall survival included age, sex, initial tumor staging and response to treatment. Of the 168 patients screened, 16 were excluded due to missing data or lack of 5-year follow-up. In addition to achievement of complete/partial remission (adjusted relative risk [RR], 0.215; p = 0.0001) and advanced stage (II-IV vs. I - II; adjusted RR, 1.55; p = 0.0023), post-treatment hemoglobin values were an independent predictor of survival (adjusted RR per 1-g/dL increment, 0.76; p = 0.0041). In the present analysis, pretreatment hemoglobin values were associated with only marginal risk reduction (adjusted RR per 1-g/dL increment, 0.985; p = 0.049). Post-treatment hemoglobin values appear to provide a strong independent predictor of 5-year survival in elderly aggressive NHL, supporting the potential role of anemia correction in this group of patients.

CHOP-rituximab with pegylated liposomal doxorubicin for the treatment of elderly patients with diffuse large B-cell lymphoma

Thirty untreated patients, median age 69 years (range 60 - 75 years), with diffuse large B-cell lymphoma (B-DLCL) were treated with a pegylated liposomal doxorubicin (PL-doxorubicin) modified CHOP-rituximab regimen. PL-doxorubicin 30 mg/m2, was given in combination with standard dosage of prednisone, vincristine, cyclophosphamide, rituximab (according to CHOP-R regimen) every 21 days for six courses. Cardiac toxicity was evaluated by mean of echocardiography for left ventricular ejection fraction (LVEF) evaluations and serum troponin-I levels. Overall response and complete response rates were 76% and 59%. Projected two year event free survival and overall survival are 65.5% and 68.5%. No treatment-related mortality was documented. WHO grade III-IV neutropenia and thrombocytopenia were 86% and 3%. Extra-hematological III-IV toxicity was represented, respectively, by a single case of infection, mucositis, and bleeding. LVEF evaluations and the troponin levels did not show significant changes over the course of the treatment. One patient with a previous history of atrial fibrillation experienced a single episode of arrhythmia. None of the patients developed palmar-plantar erythrodysesthesia. This regimen appears an active regimen for the treatment of elderly patients with B-DLCL. The replacement of conventional doxorubicin with PL-doxorubicin seems to be associated with a negligible incidence of extra-hematological toxicity, in particular cardiac and infectious complications.

Fludarabine Plus Mitoxantrone With and Without Rituximab Versus CHOP With and Without Rituximab As Front-Line Treatment for Patients With Follicular Lymphoma

Purpose

Promising new therapeutic options for follicular lymphoma (FL) include fludarabine plus mitoxantrone (FM) and the mouse/human anti-CD20 antibody, rituximab. We performed a randomized comparative trial of FM with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) front-line chemotherapy with and without sequential rituximab.

Patients and Methods

All previously untreated CD20+ FL patients presenting in 15 Italian cooperative institutions from October 1999 were randomly allocated to FM or CHOP. Following clinical or molecular restaging, patients in complete remission (CR) with bcl-2/IgH negativity (CR−) received no further treatment; those in CR with bcl-2/IgH positivity (CR+) received rituximab, as did those in partial remission (PR) with bcl-2/IgH negativity (PR−) or positivity (PR+); nonresponders (NR subgroup) were off study.

Results

After chemotherapy, the FM arm achieved higher rates of CR (68% [49 of 72 patients] v 42% [29 of 68 patients]; P = .003) and CR− (39% [28 of 72 patients] v 13 of 68 patients [19%]; P = .001). Rituximab elicited CR− in 55 of 95 treated patients (58%). The final CR− rate was higher in the FM arm (71% [51 of 72 patients] v 51% [35 of 68 patients]; P = .01). However, with a median follow-up of 19 months (range, 9 to 37 months), no statistically significant difference was found among the various study arms in terms of both progression-free (PFS) and overall survival (OS).

Conclusion

These results indicate that FM is superior to CHOP for front-line treatment of FL and that rituximab is an effective sequential treatment option. However, they also confirm that this superiority is unlikely to translate into either better PFS or OS.

B-cell compartment as the selective target for the treatment of immune thrombocytopenias

BACKGROUND AND OBJECTIVES

Rituximab is a chimeric anti-CD20 monoclonal antibody active against normal and malignant B cells. Treatment with rituximab is associated with the development of a severe (even if transient) B-cell depletion from peripheral blood and lymphatic tissues. These effects could be useful in autoimmune diseases in order to interfere with the production of pathologic antibodies.

DESIGN AND METHODS

To investigate this, we treated 20 patients with rituximab 375 mg/m2 i.v. every 7 days for 4 times. These 20 patients all had active and symptomatic autoimmune thrombocytopenia that had relapsed or was refractory to standard therapies (15 had idiopathic thrombocytopenic purpura, 1 idiopathic thrombocytopenia and neutropenia, 2 thrombocytopenia and concomitant undifferentiated connective tissue disease, and 2 had thrombocytopenia and concomitant B-cell lymphoprolipherative disorders). Only treatment with steroids, if strictly necessary to maintain a safe number of platelets, was allowed during the period of rituximab administration, but only patients who reached steroid discontinuation (previously not possible) were considered responders.

RESULTS

Treatment was well tolerated and no acute or delayed toxic events were recorded. Rituximab proved to be active in 13/20 patients, with 9 complete and 4 partial responses. In 10/13 (77%) the response (platelet level > 50x10(9)/L) was prompt, being achieved already after the first of the four planned infusions. After a median follow-up of 180 days (range: 60-480) 4 patients had relapsed. Age < or = 60 years was correlated with a better response rate (p=0.03). No correlation was observed between response and gender, time from diagnosis to treatment (< 12 vs > 12 months), total and CD20+ lymphocyte count, level of CD20 expression on B cells before the therapy and pharmacokinetics of the drug.

INTERPRETATION AND CONCLUSIONS

Rituximab appears to be a promising immunotherapeutic agent for the treatment of autoimmune thrombocytopenias.

Early autologous stem-cell transplantation versus conventional chemotherapy as front-line therapy in high-risk, aggressive non-Hodgkin's lymphoma: an Italian multicenter randomized trial

PURPOSE

To evaluate the role of early intensification with high-dose therapy (HDT) and autologous stem-cell transplantation (ASCT) as front-line chemotherapy for patients with high-risk, histologically aggressive non-Hodgkin's lymphoma (NHL).

PATIENTS AND METHODS

We planned a multicenter, randomized trial to compare a conventional chemotherapy regimen of methotrexate with leucovorin rescue, doxorubicin, cyclophosphamide, vincristine, prednisone, and bleomycin (MACOP-B; arm A) with an abbreviated regimen of MACOP-B (8 weeks) followed by HDT and ASCT (arm B) for intermediate-high-risk/high-risk patients (according to the age-adjusted International Prognostic Index). From September 1994 to April 1998, 150 patients with aggressive lymphoma were enrolled onto the trial. Seventy-five patients were randomly assigned to arm A and 75 patients were randomly assigned to arm B. In both arms, involved-field radiation therapy (36 Gy) was delivered to the site of bulky disease.

RESULTS

The rate of complete response was 68% in arm A and 76% in arm B (P = not significant [NS]). Three toxic deaths (4%) occurred in arm B and one (1%) occurred in arm A (P = NS). In arm B, 30 patients (40%) did not undergo HDT and ASCT. According to the intention-to-treat analysis at a median follow-up of 24 months, 5-year overall survival probability in arms A and B was 65% and 64% (P =.95), 5-year progression-free survival was 49% and 61% (P =.21), and 5-year relapse-free survival was 65% and 77% (P =.22), respectively.

CONCLUSION

Abbreviated chemotherapy followed by intensification with HDT-ASCT is not superior to conventional chemotherapy in patients with high-risk, aggressive NHL. Additional randomized trials will clarify whether HDT-ASCT as front-line therapy after a complete course of conventional chemotherapy improves survival in this group of patients.

Ifosfamide, epirubicin and etoposide regimen as salvage and mobilizing therapy for relapsed/refractory lymphoma patients

BACKGROUND AND OBJECTIVES

Therapy for relapsed/refractory lymphomas should be based only on drugs not included in the front-line chemotherapy regimens. We adopted the strategy of using salvage chemotherapy to debulk disease and simultaneously mobilize stem cells, using a regimen based on ifosfamide and etoposide, (drugs not usually used for front-line treatment).

DESIGN AND METHODS

A three-drug combination of ifosfamide, epirubicin and etoposide (IEV) was used to treat 62 patients with relapsing or refractory aggressive non-Hodgkin's lymphoma (NHL; n=51) or Hodgkin's disease (HD; n=11). Forty-five of the patients were studied for the feasibility of peripheral blood stem cell (PBSC) harvest.

RESULTS

The overall and complete response (CR) rates were, respectively, 77% and 32% in the NHL subset and 81% and 45% in the HD subset. Among the 17 patients who achieved CR after IEV but did not have a subsequent transplantation, the median duration of the response was 9 months (range, 2 to 14 months). Mobilization was successful in 33 of 45 (71%) patients. Among the 45 who proceeded to autotransplantation, 27 (60%) were in CR status after the autograft; 23/45 (51%) patients are currently in continuous CR with a median follow-up of 25 months (range, 10-68 months); the relapse-free survival curve shows 83% in this state at 60 months. Twenty-three (37%) patients are currently in continuous CR with a median follow-up of 25 months. Clinical and hematologic toxic effects were mild.

INTERPRETATION AND CONCLUSIONS

Our results indicate the efficacy of the IEV regimen in inducing a good remission rate. IEV is a predictable and highly effective mobilization regimen in relapsed/refractory patients with aggressive NHL or HD.

The lung as a target organ in patients with hematologic disorders

The lung is one of the organs most severely affected by complications during the course of hematologic disorders. In the last years an impressive amount of progress has been made in clarifying the pathogenesis of lung diseases, particularly those occurring in conditions of severe immunosuppression such as bone marrow transplantion, acquired immunodeficiency syndrome or leukemia. Peculiar anatomical characteristics render the lung parenchyma highly susceptible to infections, but the clinical outcome is due not only to the injury induced by the pathogens but also to their interactions with inflammatory cells and particularly to the effects of a wide network of secreted cytokines. Polymorphonuclear cells, macrophages, lymphocytes and structural pulmonary cells (epithelial cells, interstitial cells) generate a variety of cytokines and growth factors which, in turn, may be responsible for the majority of the clinical effects in response to infections, such as those of Pneumocystis carinii and cytomegalovirus, but also to certain drugs or to radiation. The pathogenesis of graft-versus-host disease (GVHD) is still poorly understood, but animal models seem to demonstrate the involvement of a number of cytokines and growth factors, together with toxic effects induced by conditioning regimens.

Clinical implications of serum levels of soluble CD23 and tumor necrosis factor alpha in low-grade non-Hodgkin's lymphoma

In the last few years the research for new biological features in low-grade non-Hodgkin's lymphoma has provided important results. Several biological parameters are under evaluation and, in particular, cytokines and soluble receptors levels are showing their importance as prognostic parameters. In the present study, serum levels of tumor necrosis factor alpha (TNF-alpha) and soluble CD23 (sCD23) were measured at the time of diagnosis and after induction polychemotherapy in 40 patients with newly diagnosed low-grade non-Hodgkin's lymphoma (LG-NHL). The treatments were CIOP (cyclophosphamide, idarubicin, vincristine, prednisone) regimen for 28 patients and FMP (fludarabine, mitoxantrone, prednisone) scheme for 12 patients. Pretreatment levels of TNF-alpha were highly elevated in patiets with LG-NHL compared with healthy controls (p = 0.005) and were significantly correlated with the Ann Arbor stage (p = 0.001). sCD23 was detected in 35 patients at diagnosis and were markedly increased in LG-NHL patients when compared to healthy controls (p = 0.005); patients with advanced stage presented higher values than those with early stage disease (p = 0.002). All the complete responders (20/40, 50%) showed a decrease of TNF-alpha and sCD23 levels. By contrast, the combination of high levels of TNF-alpha and sCD23 correspond to a group of non-responders. Our results suggest that TNF-alpha and sCD23 are specific prognostic parameters for LG-NHL, and that they could be used as tumor markers within a potential biological prognostic index.

All-trans retinoic acid and in vitro cytokine production by acute promyelocytic leukemia cells

Leukemic cells spontaneously secrete cytokines involved in the proliferation of the clone; in this study we evaluated the effects of all-trans retinoic acid (ATRA) on the in vitro autocrine production of cytokines by acute myeloid leukemia cells. Thirty acute nonlymphoid leukemia cases (ANLL) (10 APL and 20 ANLL of other cytotypes than APL) were studied; the in vitro secretions of IL-1 alpha, IL-3, IL-4, IL-6, IL-10, G-CSF, GM-CSF, TNF-alpha were tested with and without ATRA addition. After 5 d exposure to ATRA 10(-6) M APL-treated samples showed a significant reduction of IL-6 (p = 0.008) and GM-CSF (p = 0.03) and a significant increase of IL-1 alpha (p = 0.01) production, if compared to untreated APL samples. No difference was seen in IL-3, IL-10 and IL-4 productions; G-CSF production resulted absent in all but 3 APL cases, in which addition of ATRA determined increase in the production. Interestingly, the 3 G-CSF-producing cases did not obtain clinical remission with ATRA; GM-CSF and IL-6 were spontaneously produced by all the cases, and 7 of 10 APL patients subsequently obtained complete remission after induction. TNF-alpha was produced only in 1 case. No statistical difference was seen in all the productions obtained from other than promyelocytic acute leukemic cells, both with and without ATRA addition. However, it is noteworthy that the production of IL-6 was more than twice as high in ANLL non-APL than in APL cases. In conclusion, these data could thus suggest possible complementary mechanisms of the exhaustion of the leukemic clone upon treatment with ATRA.