End points in clinical trials in diffuse large B-cell lymphoma: time for more dialogue?

We observed lack of clarity and consistency in end point definitions of large randomized clinical trials in diffuse large B-cell lymphoma. These inconsistencies are such that trials might, in fact, address different clinical questions. They complicate interpretation of results, including comparisons across studies. Problems arise from different ways to account for events occurring after randomization including absence of improvement in disease status, treatment discontinuation or the initiation of new therapy. We call for more dialogue between stakeholders to define with clarity the questions of interest and corresponding end points. We illustrate that assessing different end point rules across a range of plausible patient journeys can be a powerful tool to facilitate such a discussion and contribute to better understanding of patient-relevant end points.

What is this article about? This article talks about the lack of clarity and consistency in the definitions of outcomes used in clinical trials that investigate new treatments for diffuse large B-cell lymphoma. This is mainly due to how these different outcome definitions handle events such as absence of improvement in disease status, treatment discontinuation or initiation of new treatment. The authors discuss how these inconsistencies make it hard to interpret the results of individual clinical trials and to compare results across clinical trials.Why is it important? Defining the above events and consequently defining outcomes affects what we can learn from the trials and can lead to different results. Some approaches may not reflect good and bad outcomes for patients appropriately. This makes it challenging for patients, physicians, health authorities and payors to understand the true benefit of treatments under investigation and which one is better.What are the key take-aways? This article serves as a call-to-action for more dialogue among all stakeholders involved in drug development and the decision-making process related to drug evaluations. There is an urgent need for clinical trials to be designed with more clarity and consistency on what is being measured so that relevant questions for patients and prescribing physicians are addressed. Understanding patient journeys will be key to successfully understand what truly matters to patients and how to measure the benefit of new treatments. Such discussions will contribute toward more clarity and consistency in the evaluation of new treatments.

Durable response after tisagenlecleucel in adults with relapsed/refractory follicular lymphoma: ELARA trial update.

ABSTRACT: Tisagenlecleucel is approved for adults with relapsed/refractory (r/r) follicular lymphoma (FL) in the third- or later-line setting. The primary analysis (median follow-up, 17 months) of the phase 2 ELARA trial reported high response rates and excellent safety profile in patients with extensively pretreated r/r FL. Here, we report longer-term efficacy, safety, pharmacokinetic, and exploratory biomarker analyses after median follow-up of 29 months (interquartile range, 22.2-37.7). As of 29 March 2022, 97 patients with r/r FL (grades 1-3A) received tisagenlecleucel infusion (0.6 × 108-6 × 108 chimeric antigen receptor-positive viable T cells). Bridging chemotherapy was allowed. Baseline clinical factors, tumor microenvironment, blood soluble factors, and circulating blood cells were correlated with clinical response. Cellular kinetics were assessed by quantitative polymerase chain reaction. Median progression-free survival (PFS), duration of response (DOR), and overall survival (OS) were not reached. Estimated 24-month PFS, DOR, and OS rates in all patients were 57.4% (95% confidence interval [CI], 46.2-67), 66.4% (95% CI, 54.3-76), and 87.7% (95% CI, 78.3-93.2), respectively. Complete response rate and overall response rate were 68.1% (95% CI, 57.7-77.3) and 86.2% (95% CI, 77.5-92.4), respectively. No new safety signals or treatment-related deaths were reported. Low levels of tumor-infiltrating LAG3+CD3+ exhausted T cells and higher baseline levels of naïve CD8+ T cells were associated with improved outcomes. Tisagenlecleucel continued to demonstrate highly durable efficacy and a favorable safety profile in this extended follow-up of 29 months in patients with r/r FL enrolled in ELARA. This trial was registered at www.clinicaltrials.gov as #NCT03568461.

Effectiveness of tisagenlecleucel versus real-world standard of care in relapsed/refractory follicular lymphoma.

Aim: To contextualize the effectiveness of tisagenlecleucel versus real-world standard of care (SoC) in relapsed/refractory follicular lymphoma. Materials & methods: A retrospective indirect matched comparison study using data from the phase II ELARA trial and the US Flatiron Health Research Database. Results: Complete response rate was 69.1 versus 17.7% and the overall response rate was 85.6 versus 58.1% in tisagenlecleucel versus SoC, post weighting by odds. For overall survival, an estimated reduction in the risk of death was observed in favor of tisagenlecleucel over SoC. The hazard ratio for progression-free survival was 0.45 (95% CI: 0.26, 0.88), and for time-to-next treatment was 0.34 (95% CI: 0.15, 0.78) with tisagenlecleucel versus SoC. Conclusion: A consistent trend toward improved efficacy end points was observed in favor of tisagenlecleucel versus SoC.

Assessment of Healthcare Resource Utilization and Hospitalization Costs in Patients With Relapsed or Refractory Follicular Lymphoma Undergoing CAR-T Cell Therapy With Tisagenlecleucel: Results From the ELARA Study.

Follicular lymphoma (FL) is generally considered an indolent disease, although patients with relapsing FL experience progressively shorter durations of response to second or later lines of therapy. The ongoing ELARA trial in adult patients with relapsed/refractory (r/r) FL treated with tisagenlecleucel demonstrated an overall response rate of 86.2% and a complete response rate of 69.1%, with no treatment-related deaths. Tisagenlecleucel was administered in the outpatient setting in 18% of patients in ELARA; however, there is limited knowledge concerning the impact of inpatient versus outpatient tisagenlecleucel administration on healthcare resource utilization (HCRU) among patients with r/r FL. Here, we present the first HCRU analysis among patients with r/r FL who received tisagenlecleucel in the Phase II, single-arm, multicenter ELARA trial. HCRU was characterized using hospitalization data from day 1 to month 2 after tisagenlecleucel infusion. Information on length of stay, facility use, and discharge was assessed in patients who received tisagenlecleucel in the outpatient or inpatient setting. All costs were inflated to 2020 US dollars. As of August 3, 2021 (20-month median follow-up), 17/97 (18%) r/r FL patients were infused in an outpatient setting. Patients infused in the outpatient setting generally had favorable Eastern Cooperative Oncology Group performance status and Follicular Lymphoma International Prognostic Index scores, and less bulky disease at baseline. However, the outpatients had higher proportions of patients with grade 3A FL, primary refractory disease, and >5 lines of prior therapy compared with inpatients. Forty-one percent of patients treated in the outpatient setting did not require hospitalization within 30 days after infusion, and outpatients who did require hospitalization had a shorter average length of stay compared with inpatients (5 versus 13 days). No outpatients required intensive care unit (ICU) admission, whereas 9% of inpatients were admitted to the ICU. The mean postinfusion hospitalization costs were $7477 and $40,054 in the outpatient and inpatient settings, respectively. Efficacy between both groups was similar. Tisagenlecleucel can be safely administered to some patients in the outpatient setting, which may reduce HCRU for patients with r/r FL.

Randomized Phase III Trial Evaluating Spartalizumab Plus Dabrafenib and Trametinib for BRAF V600-Mutant Unresectable or Metastatic Melanoma.

PURPOSE: Preclinical data suggest the combination of an anti-programmed death receptor 1 antibody plus dabrafenib and trametinib to have superior antitumor activity compared with dabrafenib plus trametinib alone. These observations are supported by translational evidence suggesting that immune checkpoint inhibitors plus targeted therapy may improve treatment outcomes in patients with BRAF V600-mutant metastatic melanoma. COMBI-i is a phase III trial evaluating spartalizumab, an anti-programmed death receptor 1 antibody, in combination with dabrafenib and trametinib (sparta-DabTram), versus placebo plus dabrafenib and trametinib (placebo-DabTram) in patients with BRAF V600-mutant unresectable or metastatic melanoma. METHODS: Patients received spartalizumab 400 mg intravenously every 4 weeks plus dabrafenib 150 mg orally twice daily and trametinib 2 mg orally once daily or placebo-DabTram. Participants were age ≥ 18 years with unresectable or metastatic BRAF V600-mutant melanoma. The primary end point was investigator-assessed progression-free survival. Overall survival was a key secondary end point (ClinicalTrials.gov identifier: NCT02967692). RESULTS: At data cutoff (July 1, 2020), the median progression-free survival was 16.2 months (95% CI, 12.7 to 23.9 months) in the sparta-DabTram arm versus 12.0 months (95% CI, 10.2 to 15.4 months) in the placebo-DabTram arm (hazard ratio, 0.82 [95% CI, 0.66 to 1.03]; P = .042 [one-sided; nonsignificant]). The objective response rates were 69% (183 of 267 patients) versus 64% (170 of 265 patients), respectively. Grade ≥ 3 treatment-related adverse events occurred in 55% (146 of 267) of patients in the sparta-DabTram arm and 33% (88 of 264) in the placebo-DabTram arm. CONCLUSION: The study did not meet its primary end point; broad first-line use of sparta-DabTram is not supported by these results. Further biomarker-driven investigation may identify patient subpopulations who could benefit from checkpoint inhibitor plus targeted therapy combinations.

Second-Line Tisagenlecleucel or Standard Care in Aggressive B-Cell Lymphoma.

BACKGROUND: Patient outcomes are poor for aggressive B-cell non-Hodgkin's lymphomas not responding to or progressing within 12 months after first-line therapy. Tisagenlecleucel is an anti-CD19 chimeric antigen receptor T-cell therapy approved for diffuse large B-cell lymphoma after at least two treatment lines. METHODS: We conducted an international phase 3 trial involving patients with aggressive lymphoma that was refractory to or progressing within 12 months after first-line therapy. Patients were randomly assigned to receive tisagenlecleucel with optional bridging therapy (tisagenlecleucel group) or salvage chemotherapy and autologous hematopoietic stem-cell transplantation (HSCT) (standard-care group). The primary end point was event-free survival, defined as the time from randomization to stable or progressive disease at or after the week 12 assessment or death. Crossover to receive tisagenlecleucel was allowed if a defined event occurred at or after the week 12 assessment. Other end points included response and safety. RESULTS: A total of 322 patients underwent randomization. At baseline, the percentage of patients with high-grade lymphomas was higher in the tisagenlecleucel group than in the standard-care group (24.1% vs. 16.9%), as was the percentage with an International Prognostic Index score (range, 0 to 5, with higher scores indicating a worse prognosis) of 2 or higher (65.4% vs. 57.5%). A total of 95.7% of the patients in the tisagenlecleucel group received tisagenlecleucel; 32.5% of the patients in the standard-care group received autologous HSCT. The median time from leukapheresis to tisagenlecleucel infusion was 52 days. A total of 25.9% of the patients in the tisagenlecleucel group had lymphoma progression at week 6, as compared with 13.8% of those in the standard-care group. The median event-free survival in both groups was 3.0 months (hazard ratio for event or death in the tisagenlecleucel group, 1.07; 95% confidence interval, 0.82 to 1.40; P = 0.61). A response occurred in 46.3% of the patients in the tisagenlecleucel group and in 42.5% in the standard-care group. Ten patients in the tisagenlecleucel group and 13 in the standard-care group died from adverse events. CONCLUSIONS: Tisagenlecleucel was not superior to standard salvage therapy in this trial. Additional studies are needed to assess which patients may obtain the most benefit from each approach. (Funded by Novartis; BELINDA ClinicalTrials.gov number, NCT03570892.).

Tisagenlecleucel in adult relapsed or refractory follicular lymphoma: the phase 2 ELARA trial.

Tisagenlecleucel is an autologous anti-CD19 chimeric antigen receptor-T cell therapy with clinically meaningful outcomes demonstrated in patients with relapsed/refractory (r/r) B-cell lymphoma. In a previous pilot study of tisagenlecleucel in r/r follicular lymphoma (FL), 71% of patients achieved a complete response (CR). Here we report the primary, prespecified interim analysis of the ELARA phase 2 multinational trial of tisagenlecleucel in adults with r/r FL after two or more treatment lines or who relapsed after autologous stem cell transplant (no. NCT03568461). The primary endpoint was CR rate (CRR). Secondary endpoints included overall response rate (ORR), duration of response, progression-free survival, overall survival, pharmacokinetics and safety. As of 29 March 2021, 97/98 enrolled patients received tisagenlecleucel (median follow-up, 16.59 months; interquartile range, 13.8-20.21). The primary endpoint was met. In the efficacy set (n = 94), CRR was 69.1% (95% confidence interval, 58.8-78.3) and ORR 86.2% (95% confidence interval, 77.5-92.4). Within 8 weeks of infusion, rates of cytokine release syndrome were 48.5% (grade ≥3, 0%), neurological events 37.1% (grade ≥3, 3%) and immune effector cell-associated neurotoxicity syndrome (ICANS) 4.1% (grade ≥3, 1%) in the safety set (n = 97), with no treatment-related deaths. Tisagenlecleucel is safe and effective in extensively pretreated r/r FL, including in high-risk patients.

Combined PD-1, BRAF and MEK inhibition in advanced BRAF-mutant melanoma: safety run-in and biomarker cohorts of COMBI-i.

Immune and targeted therapies achieve long-term survival in metastatic melanoma; however, new treatment strategies are needed to improve patients' outcomes1,2. We report on the efficacy, safety and biomarker analysis from the single-arm safety run-in (part 1; n = 9) and biomarker (part 2; n = 27) cohorts of the randomized, placebo-controlled, phase 3 COMBI-i trial (NCT02967692) of the anti-PD-1 antibody spartalizumab, in combination with the BRAF inhibitor dabrafenib and MEK inhibitor trametinib. Patients (n = 36) had previously untreated BRAF V600-mutant unresectable or metastatic melanoma. In part 1, the recommended phase 3 regimen was identified based on the incidence of dose-limiting toxicities (DLTs; primary endpoint): 400 mg of spartalizumab every 4 weeks plus 150 mg of dabrafenib twice daily plus 2 mg of trametinib once daily. Part 2 characterized changes in PD-L1 levels and CD8+ cells following treatment (primary endpoint), and analyzed additional biomarkers. Assessments of efficacy and safety were key secondary endpoints (median follow-up, 24.3 months). Spartalizumab plus dabrafenib and trametinib led to an objective response rate (ORR) of 78%, including 44% complete responses (CRs). Grade ≥3 treatment-related adverse events (TRAEs) were experienced by 72% of patients. All patients had temporary dose modifications, and 17% permanently discontinued all three study drugs due to TRAEs. Early progression-free survival (PFS) events were associated with low tumor mutational burden/T cell-inflamed gene expression signature (GES) or high immunosuppressive tumor microenvironment (TME) GES levels at baseline; an immunosuppressive TME may also preclude CR. Overall, the efficacy, safety and on-treatment biomarker modulations associated with spartalizumab plus dabrafenib and trametinib are promising, and biomarkers that may predict long-term benefit were identified.

The investigational agent MLN2238 induces apoptosis and is cytotoxic to CLL cells in vitro, as a single agent and in combination with other drugs.

Chronic lymphocytic leukaemia (CLL) is the most common haematological malignancy in the U.S. The course of the disease has been shown to be negatively impacted by increased levels of BCL2. Strategies to downregulate BCL2 and shift the balance towards cellular demise are actively being explored. Therefore, we examined whether the investigational agent MLN2238 could inhibit the proteasomal machinery and induce CLL cell death while also downregulating BCL2. MLN2238-induced cell death was studied in peripheral blood mononuclear cells from 28 CLL patients. MLN2238 produced a dose-dependent reduction in BCL2 and CLL cell viability with maximum cell death observed at a 50 nmol/l concentration by 48 h. Annexin-V staining, PARP1 and caspase-3 cleavage along with an increase in mitochondrial membrane permeability were noted after cells were treated with MLN2238; however, apoptosis was only partially blocked by the pan-caspase inhibitor z-VAD.fmk. Furthermore, we observed enhanced anti-CLL effects in tumour cells treated with either a combination of MLN2238 and the BH3 mimetic AT-101 or MLN2238 and fludarabine. Together, our data suggest the potential for proteasome inhibitor based therapy in CLL and the rationale design of drug combination strategies based on CLL biology.

Neem leaf extract induces cell death by apoptosis and autophagy in B-chronic lymphocytic leukemia cells.

Chronic lymphocytic leukemia (CLL) is the most common adult leukemia and is currently incurable. To expand the therapeutic armamentarium, we investigated neem leaf extract (NLE) after a patient with CLL demonstrated disease regression upon taking oral NLE. NLE-mediated apoptosis was examined in peripheral blood mononuclear cells (PBMCs) from 41 patients with CLL. NLE induced a dose-dependent reduction in CLL cell viability with significant apoptosis observed at 0.06% (w/v) by 24 h. Annexin-V staining and poly(ADP-ribose) polymerase 1 (PARP-1) and caspase 3 cleavage were observed after NLE treatment. However, a pan-caspase inhibitor only partially blocked NLE-mediated cell death. NLE also caused loss of mitochondrial outer membrane permeability and nuclear translocation of apoptosis-inducing factor. Furthermore, NLE treatment resulted in LC3-I cleavage. Biochemical analyses revealed that NLE also inhibits Bcl-2 and p53 proteins. In summary, NLE exhibits anti-leukemic properties in patient primary CLL cells and demonstrates clinical efficacy, warranting further investigation as a potential therapy for CLL.

Retrospective analysis of prognosticators in patients with relapsed Hodgkin's Lymphoma treated with autologous transplant: results of a single center.

Hodgkin's Lymphoma (HL) is highly chemoresponsive, and majority of patients respond to therapy except for a small number which require high-dose therapy and stem cell rescue for salvage. We report the results of a single-center experience in 41 patients with relapsed HL treated with high-dose therapy at the time of relapse from the year 1989-2010. The 7-year OS for the group is 39.2 %; the median progression-free survival is 30.6 months. Univariate analysis identified refractory disease at transplant and extranodal involvement as important prognosticators. The 100-day mortality was 5 %. The most common cause for delayed mortality was disease progression. The incidence of secondary malignancy in the group was 2 %. Our results reinforce the significance of long-term follow up as late relapses are observed. Additionally, identifying biological prognosticators and implying them for treatment may improve the outcomes in poor-risk patients.

Development and characterization of a novel human Waldenström macroglobulinemia cell line: RPCI-WM1, Roswell Park Cancer Institute - Waldenström Macroglobulinemia 1.

Understanding the biology of Waldenström macroglobulinemia is hindered by a lack of preclinical models. We report a novel cell line, RPCI-WM1, from a patient treated for WM. The cell line secretes human immunoglobulin M (h-IgM) with κ-light chain restriction identical to the primary tumor. The cell line has a modal chromosomal number of 46 and harbors chromosomal changes such as deletion of 6q21, monoallelic deletion of 9p21 (CDKN2A), 13q14 (RB1) and 18q21 (BCL-2), with a consistent amplification of 14q32 (immunoglobulin heavy chain; IgH) identical to its founding tumor sample. The clonal relationship is confirmed by identical CDR3 length and single nucleotide polymorphisms as well as a matching IgH sequence of the cell line and founding tumor. Both also harbor a heterozygous, non-synonymous mutation at amino acid 265 in the MYD88 gene (L265P). The cell line expresses most of the cell surface markers present on the parent cells. Overall, RPCI-WM1 represents a valuable model to study Waldenström macroglobulinemia.

Acyclovir prophylaxis against varicella zoster virus reactivation in multiple myeloma patients treated with bortezomib-based therapies: a retrospective analysis of 100 patients.

BACKGROUND: Previous studies have indicated that, in patients with multiple myeloma (MM), bortezomib is associated with an increased incidence of herpes zoster, resulting from reactivation of latent varicella zoster virus (VZV). OBJECTIVE: Our objective was to determine whether increased risk of VZV reactivation could be abrogated by using prophylactic acyclovir. METHODS: We retrospectively evaluated 100 consecutive MM patients treated with bortezomib-based therapies at the Roswell Park Cancer Institute for development of herpes zoster. Frontline and relapsed/refractory patients were included, and patients received bortezomib alone or in combination with agents such as doxorubicin, melphalan, or dexamethasone. All patients received >4 weeks of acyclovir prophylaxis (400 mg twice daily), which was initiated prior to starting treatment with bortezomib and discontinued 4 weeks following bortezomib. RESULTS: Median patient age was 62 years, 57% were male, and most (56%) had Durie-Salmon stage IIIA MM. None of the 100 MM patients receiving acyclovir prophylaxis developed herpes zoster during treatment with bortezomib, irrespective of patients receiving a wide variety of concomitant antimyeloma therapies and regardless of response to bortezomib-based therapy. One additional patient, found to be noncompliant with acyclovir therapy, experienced VZV reactivation, having received 3 cycles of bortezomib (3 weeks each cycle) in combination with cyclophosphamide and dexamethasone. LIMITATIONS: Limitations of the study include its small size and retrospective nature. CONCLUSIONS: The increased risk of VZV reactivation observed in previous studies of bortezomib-based therapy was completely abrogated in this series of patients who received prophylaxis with acyclovir.

Downregulation of BCL2 by AT-101 enhances the antileukaemic effect of lenalidomide both by an immune dependant and independent manner.

Over-expression of anti-apoptotic BCL2 has been reported in chronic lymphocytic leukaemia (CLL), but targeting BCL2 alone did not yield appreciable clinical results. However, it was demonstrated that BCL2 inhibitors enhanced the clinical efficacy of chemo and immunotherapeutics. Lenalidomide, an immunomodulator, is clinically effective in CLL and can enhance the anti-CLL effects of CD20 targeting monoclonal antibody, rituximab. Here, we investigated the mechanism of immune-directed killing of lenalidomide in CLL and evaluated if concurrent targeting of CD20 and BCL2 can enhance this effect. In vitro treatment with lenalidomide enhanced the antibody-mediated cellular cytotoxicity (ADCC) directed by rituximab in autologous leukaemic cells. Furthermore, peripheral blood mononuclear cells obtained from patients after treatment with lenalidomide and rituximab showed increased ADCC in vitro versus control (pre-treatment sample). This effect was further enhanced with pre-treatment of tumour cells with AT-101 (a BH3 mimetic that functions as BCL2 antagonist). Our data suggest that AT-101 in combination with lenalidomide can potentially be an effective therapeutic regimen for CLL.

Bortezomib mitigates adverse prognosis conferred by Bcl-2 overexpression in patients with relapsed/refractory multiple myeloma.

Overexpression of the Bcl-2 family of genes results in increased transcription of anti-apoptotic proteins. In vitro data suggest that this may enhance acquired chemoresistance and correlate with extramedullary invasion. This has led to pursuing the Bcl-2 family of proteins as therapeutic targets in several malignant disorders, including multiple myeloma (MM). The impact of novel therapeutic agents such as bortezomib on these molecular markers is not known. We investigated the association between the expression of anti-apoptotic members of the Bcl-2 family and the efficacy of bortezomib in patients with relapsed/refractory MM. Gene expression data generated prospectively from large clinical trials were utilized. Hypothesis testing using a multisample test for equivalence was performed. The association between Bcl-2 expression levels and clinical response was negated in bortezomib-treated patients (p = 0.014), while not so in dexamethasone-treated patients (p = 0.92). Similar results were noted for variant 2 of the Mcl-1 gene (p = 0.003). Results for Bcl-xl did not meet the level of significance. Thus, the importance of the Bcl-2 family of proteins as prognostic markers in MM should be reassessed in the novel therapeutic agent era. Our data suggest that bortezomib may overcome the prognostic effect conferred by overexpression of some of the anti-apoptotic Bcl-2 family of genes in patients with relapsed/refractory MM.

Novel approaches to modulate apoptosis resistance: basic and clinical implications in the treatment of chronic lymphocytic leukemia (CLL).

Chronic lymphocytic leukemia (CLL) is an archetype of malignancy resulting from defects in apoptosis. CLL is an exclusive accumulative disorder marked by low proliferative activity and gradual accumulation of clonal B-lymphocytes blocked in the early (G0, G1) phases of the cell cycle. The heterogeneous clinical course indicates diverse in vivo biology of the leukemic cell and suggests that CLL represents diverse behavior. Understanding the molecular biology of the disease has provided insight into the mechanisms that promote tumorigenesis, specifically defective apoptotic signaling pathways. In this review we attempt to provide a comprehensive discussion of CLL including the origin of malignant lymphocytes, the apoptotic defects and the mechanisms leading to disease progression. We further discuss the therapeutic options, focusing mainly on targeted therapy using novel agents. Finally, we suggest future directions for treatment that utilize the understanding of the disease biology.

Targeted treatment for chronic lymphocytic leukemia.

The treatment of chronic lymphocytic leukemia (CLL) has evolved over the last few decades. Recognition has increased of several key components of CLL biology currently manipulated for therapeutics. A milestone in the treatment of CLL was reached with the incorporation of immunotherapy with conventional chemotherapy. The fludarabine/cyclophosphamide/rituximab combination has demonstrated survival advantage for the first time in the treatment of CLL. Several other biological compounds are being explored with the hope of improving responses, impacting survival, and ultimately curing CLL. Important agents being tested are targeted on CLL surface molecules and their ligands, signal transduction protein and oncogenes. This review provides a brief summary of the recent advances made in preclinical and clinical investigation of selected promising therapeutic agents, which lead the target-directed therapeutic approach.

Biological effects and clinical significance of lenalidomide-induced tumour flare reaction in patients with chronic lymphocytic leukaemia: in vivo evidence of immune activation and antitumour response.

Lenalidomide has demonstrated impressive antileukaemic effects in patients with chronic lymphocytic leukaemia (CLL). The mechanism(s) by which it mediates these effects remain unclear. Clinically, CLL patients treated with lenalidomide demonstrate an acute inflammatory reaction, the tumour flare reaction that is suggestive of an immune activation phenomenon. Samples from CLL patients treated with lenalidomide were used to evaluate its effect on the tumour cell and components of its microenvironment (immune cellular and cytokine). Lenalidomide was unable to directly induce apoptosis in CLL cells in vitro, however it modulated costimulatory (CD80, CD83, CD86) surface molecules on CLL cells in vitro and in vivo. Concurrently, we demonstrated that NK cell proliferation was induced by lenalidomide treatment in patients and correlated with clinical response. Cytokine analysis showed increase in levels of TNF-α post-lenalidomide treatment, consistent with acute inflammatory reaction. Furthermore, the basal cytokine profile (high IL-8, MIG, IP-10 and IL-4 levels and low IL-5, MIP1a, MIP1b, IL12/p70) was predictive of clinical response to lenalidomide. Collectively, our correlative studies provide further evidence that the antileukaemic effect of lenalidomide in CLL is mediated not only through modulation of the leukaemic clone but also through elements of the tumour microenvironment.

A steroid-independent regimen of bortezomib, liposomal doxorubicin and thalidomide demonstrate high response rates in newly diagnosed multiple myeloma patients.

Novel agents have provided a new foundation for multiple myeloma therapies. When combined with other anti-myeloma agents, these compounds significantly enhance clinical efficacy. High-dose steroids are frequently used in anti-myeloma combination regimens; however, the doses employed are often poorly tolerated, especially in patients with concurrent comorbid conditions. We hypothesized that a steroid-independent combination regimen could be developed without significant compromise of efficacy. The availability of such a regimen will be important for patients whose concurrent ailments make them poor candidates for steroid containing anti-myeloma regimens. A phase II single institute, non-randomized clinical trial was conducted to investigate a novel steroid-free three-drug combination of bortezomib (V), pegylated liposomal doxorubicin (D), and thalidomide (T), the VDT regimen. Forty-three newly diagnosed multiple myeloma patients requiring treatment were enrolled on this study. The overall response rate and complete response (CR) + near complete response (nCR) rate was 78% and 35%, respectively. Median time to progression was 29·5 months. Fatigue, rash, neuropathy, constipation and infections were the most common side effects. We concluded that VDT is a tolerable and an effective regimen capable of inducing high response rates and can be employed in patients considered to be poor candidates for steroid-based treatment regimens.