ICOS and OX40 tandem co-stimulation enhances CAR T-cell cytotoxicity and promotes T-cell persistence phenotype

Chimeric Antigen Receptor (CAR) T-cell therapies have emerged as an effective and potentially curative immunotherapy for patients with relapsed or refractory malignancies. Treatment with CD19 CAR T-cells has shown unprecedented results in hematological malignancies, including heavily refractory leukemia, lymphoma, and myeloma cases. Despite these encouraging results, CAR T-cell therapy faces limitations, including the lack of long-term responses in nearly 50-70% of the treated patients and low efficacy in solid tumors. Among other reasons, these restrictions are related to the lack of targetable tumor-associated antigens, limitations on the CAR design and interactions with the tumor microenvironment (TME), as well as short-term CAR T-cell persistence. Because of these reasons, we developed and tested a chimeric antigen receptor (CAR) construct with an anti-ROR1 single-chain variable-fragment cassette connected to CD3ζ by second and third-generation intracellular signaling domains including 4-1BB, CD28/4-1BB, ICOS/4-1BB or ICOS/OX40. We observed that after several successive tumor-cell in vitro challenges, ROR1.ICOS.OX40ζ continued to proliferate, produce pro-inflammatory cytokines, and induce cytotoxicity against ROR1+ cell lines in vitro with enhanced potency. Additionally, in vivo ROR1.ICOS.OX40ζ T-cells showed anti-lymphoma activity, a long-lasting central memory phenotype, improved overall survival, and evidence of long-term CAR T-cell persistence. We conclude that anti-ROR1 CAR T-cells that are activated by ICOS.OX40 tandem co-stimulation show in vitro and in vivo enhanced targeted cytotoxicity associated with a phenotype that promotes T-cell persistence.

Response to COVID-19 vaccination post CAR T therapy in patients with non-Hodgkin lymphoma and multiple myeloma

COVID-19 adversely affects individuals with cancer. Several studies have found that seroconversion rates among patients with hematologic malignancies are suboptimal when compared to patients without cancer. Patients with non-Hodgkin lymphoma (NHL) and multiple myeloma (MM) are immunocompromised due to impaired humoral and cellular immunity in addition to prescribed immunosuppressive therapy. Chimeric antigen receptor T-cell (CAR T) therapy is now widely used for NHL and MM, but little is known about seroconversion rates after COVID-19 vaccination among these populations. We evaluated SARS-CoV-2 spike-binding IgG antibody levels following COVID-19 vaccination among NHL and MM CAR T therapy recipients. Out of 104 CAR T infusions, 19 patients developed known COVID-19 infection post-CAR T. We tested 17 patients that received CAR T for antibody spike titers post COVID-19 vaccination, only 29 % (n = 5) were able to mount a clinically relevant antibody response (>250 IU/mL).

Predictors and Management of Relapse to Axicabtagene Ciloleucel in Patients with Aggressive B-cell Lymphoma

OBJECTIVE/BACKGROUND

Despite the success of chimeric antigen receptor (CAR) T-cell therapy in patients with aggressive non-Hodgkin lymphoma (aNHL), some patients still fail treatment, and their prognosis is dismal.

METHODS

We performed a retrospective study of aNHL patients treated with axicabtagene ciloleucel (axi-cel) at two Mayo Clinic centers between 2018 and 2020. We evaluated predictive factors, toxicities, and responses to salvage regimens after CAR T-cell therapy.

RESULTS

Thirty-four patients received axi-cel with a median length of hospitalization of 14 days. Cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome of any grade occurred in 91% and 41% of patients, respectively. Furthermore, 71% of patients responded to therapy, with 53% achieving a complete response (CR). The CRS grade and absolute lymphocyte count at leukapheresis (ALC_Leuk) correlated with CR and overall survival (OS), respectively. After a median follow-up of 6.8 months (interquartile range [IQR] 4.6-14.9), 15 patients (44%) showed progressive disease (PD). Most patients (60%) progressed during the first 3 months and had persistent CD19 tumor expression. Elevated C-reactive protein at baseline increased the risk of PD, whereas elevated ferritin increased PD and mortality risk. Twelve patients received salvage therapy, but only three responded. Median OS of relapsed/refractory patients to axi-cel was 3 months (IQR 1.3-5.1).

CONCLUSION

The grade of CRS and ALC_Leuk correlated with better outcomes to axi-cel therapy. In addition, elevated inflammatory markers at baseline were associated with PD and shorter survival. Relapses after treatment frequently occur within months after axi-cel infusion; they confer a poor prognosis and create an urgent need for novel and effective treatment options in this patient population.

Supportive Care for Patients with Lymphoma Undergoing CAR-T-cell Therapy: the Advanced Practice Provider's Perspective

PURPOSE OF REVIEW

The purpose of our paper is to describe the all-encompassing supportive care for patients with relapsed or refractory lymphoma undergoing cellular therapy, with a focus on the advanced practice provider's (APPs) perspective.

RECENT FINDINGS

Chimeric antigen receptor-T (CAR-T) cell therapy has become more available for treating relapsed or refractory B-cell hematologic malignancies, requiring proficient and adequate treatment of side effects, complications, and infections that may occur during therapy. APPs often meet these patients during the initial referral and help to support them through the CAR-T cell therapy process. As APPs acquire a complete understanding and comprehensive knowledge of how to treat, support, and guide patients with B-cell malignancies through CAR-T cell therapy, they play a pivotal role in these patients throughout their treatment. Standardization of supportive care is paramount.

Extracorporeal photopheresis for the treatment of chronic graft versus host disease

OBJECTIVES

Chronic graft versus host disease (chronic GVHD) still remains the leading cause of late morbidity and mortality for allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients. In this retrospective study, 53 consecutive allo-HSCT patients with chronic GVHD refractory to corticosteroids were treated with extracorporeal photopheresis (ECP).

METHODS

This study was performed as a retrospective single-center study. Medical records of a total of 59 patients treated with ECP for chronic GVHD were reviewed.

RESULTS

Best organ responses to ECP were observed in skin, mouth mucosa, eyes and liver. Overall response rate (ORR) to ECP was 81.2% (CR 17% and PR 64.2%). Overall survival (OS) was 84.9% and 36.7%, at 1 and 3 years, respectively. Female sex appears to have an advantage on ORR. Patients achieving ORR were able to maintain their responses with a prolonged continuation of treatments for +6 and +12 months indicating the benefits of longer ECP treatment.

DISCUSSION

We found that patients with chronic GVHD who were treated with ECP for 12 months or longer had a higher response rate. Our findings in line with the data reported previously suggest that patients responding to ECP should continue longer therapy schedules to achieve a better and sustained response. In our cohort, long-term ECP therapy was safe and well-tolerated with no significant adverse effects. Best responses were observed in the patients with skin, eye, liver and oral involvement. The ECP procedure offers the advantage relative to the problems with typical immunosuppressive agents. The female sex appeared to have an advantage based on the cumulative probability of the OR after ECP for chronic GVHD.

Treatment with anti-spike monoclonal antibodies in allogeneic HCT and CAR T-cell recipients with mild to moderate COVID-19: The Mayo Clinic experience

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Background: Prognosis of COVID-19 is poor in the setting of immunosuppression. Casirivimab/imdevimab (REGEN-COV), bamlanivimab, and sotrovimab are investigational monoclonal antibodies (MoAbs) authorized for treatment of mild/moderate COVID-19 for patients (pts) 12 years or older and who are at high-risk for progression to severe COVID-19. These neutralizing antibodies, against SARS-CoV-2 spike proteins, have been shown to decrease risk of progression to severe disease. Recipients of allogeneic stem cell transplants (allo-SCT) or chimeric antigen T cell therapy (CAR T cell) represent a high risk population. However, treatment outcomes with these MoAbs in these pts are not well described. Methods: This retrospective study included 33 consecutive adult pts who developed mild/moderate COVID-19 and received anti-spike SARS-CoV-2 MoAbs between December 2020 and November 2021. Allo-SCT (N=27) or CAR T cell (N=6) recipients were included, and outcomes were analyzed separately. Pts received REGEN-COV (N=19), bamlanivimab (N=11), or sotrovimab (N=1), missing (N=2). Results: In the allo-SCT cohort (N=27), median age at time of COVID-19 was 55 (23-76) years. Median time from allo-SCT to COVID-19 was 31 (22-64) months. Two pts received CAR T-cell therapy prior to allo-SCT. Diagnoses included leukemia or myeloid diseases (82%), lymphoma (11%), or myeloma (7%). Transplant characteristics are summarized (Table). Thirteen pts were vaccinated against SARS-CoV-2 prior to breakthrough COVID-19. Events considered included hospitalization due to COVID-19, disease progression, or death from any cause. The 6-month event-free and overall survivals were 81% and 91%, respectively. In the CAR T cell recipients cohort (N=6), 4 pts received axicabtagene ciloleucel for diffuse large B-cell or follicular lymphoma and 2 received brexucabtagene autoleucel for mantle cell lymphoma. The median follow-up was 8 (1-11) months. Two pts received autologous SCT prior to COVID-19. Median time from CAR T cell therapy to COVID-19 was 10 (3-24) months. Three pts were vaccinated prior to COVID-19. Only 1 pt was hospitalized due to severe COVID-19 requiring mechanical ventilation leading to death. Conclusions: These results show a potential benefit of MoAbs in high-risk pts, namely allo-SCT or CAR T cell recipients. Future studies should evaluate the role of prophylactic use MoAbs in these populations. A comparative analysis with a matched control cohort (who did not receive MoAbs) will be provided at the meeting. [Table: see text]

Modulation of RNA splicing associated with Wnt signaling pathway using FD-895 and pladienolide B

Alterations in RNA splicing are associated with different malignancies, including leukemia, lymphoma, and solid tumors. The RNA splicing modulators such as FD-895 and pladienolide B have been investigated in different malignancies to target/modulate spliceosome for therapeutic purpose. Different cell lines were screened using an RNA splicing modulator to test in vitro cytotoxicity and the ability to modulate RNA splicing capability via induction of intron retention (using RT-PCR and qPCR). The Cignal Finder Reporter Array evaluated [pathways affected by the splice modulators in HeLa cells. Further, the candidates associated with the pathways were validated at protein level using western blot assay, and gene-gene interaction studies were carried out using GeneMANIA. We show that FD-895 and pladienolide B induces higher apoptosis levels than conventional chemotherapy in different solid tumors. In addition, both agents modulate Wnt signaling pathways and mRNA splicing. Specifically, FD-895 and pladienolide B significantly downregulates Wnt signaling pathway-associated transcripts (GSK3β and LRP5) and both transcript and proteins including LEF1, CCND1, LRP6, and pLRP6 at the transcript, total protein, and protein phosphorylation's levels. These results indicate FD-895 and pladienolide B inhibit Wnt signaling by decreasing LRP6 phosphorylation and modulating mRNA splicing through induction of intron retention in solid tumors.

Incidence of thrombosis in relapsed/refractory B-cell lymphoma treated with axicabtagene ciloleucel: Mayo Clinic experience

Chimeric antigen receptor (CAR) T-cell therapy is effective in relapsed/refractory large B-cell lymphoma and results in a unique toxicity profile, namely cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome. The hyper-inflammatory state associated with these toxicities has been suggested to increase the risk of thrombosis. We conducted a retrospective analysis of patients treated with axicabtagene ciloleucel (axi-cel) to assess the rate of thrombosis with axi-cel therapy from the time of CAR T-cell infusion until the end of hospitalization, when performed in the inpatient setting, or up to day +30 when performed in the outpatient setting. Ninety-two (95%) of 97 patients were hospitalized during axi-cel therapy and 85 (88%) developed CRS. Fifty-five patients (57%) received concurrent anticoagulation (53 as prophylaxis). Patients with prior VTE did not have progression or evidence of new VTE. Only 2 (2.1%) patients developed VTE. These results demonstrate a low-risk for thrombosis in axi-cel recipients.

Preliminary results of a phase I trial of FT516, an off-the-shelf natural killer (NK) cell therapy derived from a clonal master induced pluripotent stem cell (iPSC) line expressing high-affinity, non-cleavable CD16 (hnCD16), in patients (pts) with relapsed/refractory (R/R) B-cell lymphoma (BCL)

7541

Background: FT516 is an investigational, NK cell cancer immunotherapy derived from a clonal master iPSC line. FT516 is engineered with a novel hnCD16 Fc receptor, demonstrated preclinically to maximize antibody-dependent cellular cytotoxicity (Zhu et al. Blood 2020). FT516 can be mass produced and made available off-the-shelf for broad pt access and multi-dose administration. Methods: This is a Phase I trial of FT516 combined with rituximab (R) in pts with R/R BCL. Treatment consists of 2 cycles, each with 3 days lympho-conditioning (fludarabine 30 mg/m2 and cyclophosphamide 500 mg/m2) and 1 dose of R followed by 3 weekly infusions of FT516 (planned doses 30-900 million/dose) with IL-2 (6 MIU after each FT516 dose). The primary objective is to identify the incidence of dose-limiting toxicity (DLT)/dose cohort and the recommended Phase II dose using a standard 3+3 design. Additional objectives include safety, tolerability, preliminary activity, pharmacokinetics, and immunogenicity. Results: Six pts (5 DLBCL, 1 FL, median age 65.5 y) have completed (5) or discontinued (1) study treatment after the DLT period (data cutoff 9 Dec 2020): 2 received 30 million cells/dose, 3 received 90 million cells/dose, and 1 received 300 million cells/dose. All pts received > 1 prior R-containing regimen, and median number of prior therapies was 3 (range 2-6), including CAR-T in 3 pts. FT516 was primarily administered in the outpatient setting. No FT516-related Grade ≥3 adverse events (AEs) or serious AEs, and no events of cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), or graft-versus-host disease (GvHD) of any grade were reported. DLT (Grade 4 neutrophil count decreased, not recovered to baseline by D29) was reported in the first pt at 30 million cells/dose and R dosing of 375 mg/m2 weekly x 4/cycle, resulting in modification of R dosing to once/cycle; no DLTs were observed with modified R dosing. Most common all grade AEs in ≥3 pts: fatigue (4 pts) and decreased appetite, nausea, neutrophil count decreased, and headache (3 pts each). Grade ≥3 AEs in ≥2 pts: neutrophil count decreased (3 pts) and febrile neutropenia and platelet count decreased (2 pts each); none considered related to FT516. Host anti-product B- or T-cell immunogenicity was not observed. Three of 4 pts treated at ≥90 million cells/dose achieved objective response (2 complete responses [CRs] and 1 partial response). Conclusions: Administration of up to 6 doses of FT516 cells, including up to 300 million cells/dose, appears to be safe and tolerable, without CRS, ICANS, or GvHD. Activity was observed, including CRs, in heavily pretreated pts. Dose escalation is ongoing. Updated clinical and translational data will be presented. Clinical trial information: NCT04023071.

Immune effector cell therapies in oncology: A systematic analysis and forecast from ClinicalTrials.gov

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Background: IEC are arguably the most promising therapy in oncology, and FDA approvals for CAR T cells are a testament to their real potential. This has led to a great growth of clinical trials (CT), making the evaluation of their associated data increasingly challenging. To facilitate this process, we performed a systematic review of ClinicalTrials.gov focused on IEC therapies in oncology. We performed an analysis of the CT data and forecast trends for 2025. Methods: CT registries were retrieved from ClinicalTrials.gov with a systematic search query. We included CT registered between 1993-2020, which used IEC-based therapies in oncology. Statistical analysis using descriptive and inferential methods allowed us to identify trends and establish forecasts. Results: We identified 938 registrations of IEC-CTs in oncology, and 51% of those were active. The most common IEC type was CAR T (51%), followed by NK (15%), TCR T (8%), TIL (8%), and CIK (3%). 69% of IEC-CTs were aimed at a specific target vs. 31% that lack that specificity. The number of annual CAR T-CTs continue to increase, and we forecast 320 registrations during 2025. Since 2018, the number of CTs using unmodified T cells and TIL has increased (largely due to metastatic melanoma studies). NK cells CTs represent 8% of all registrations, and by 2025 we anticipate that >150 NK-based CTs will be registered per year, a number similar to CAR T-CTs registered during 2020. IEC-CTs based on allogeneic sources represent 18% of all registrations and are expected to grow 2.5 fold in the next 5 years. In solid tumors, the most common IEC-CTs are based on Non-CAR studies, while in hem-malignancies 76% of CTs are CAR T. Only one solid tumor, CAR T-CT, has reached phase 2/3, while 7 CIK-CTs were used to target various organ tumors. Conclusions: IEC-CTs continue to grow exponentially and represent an active field of clinical research in oncology. Allogeneic and NK-CTs increase rapidly and are among the most promising IEC-CTs. A rising proportion of CTs in solid tumors are using CIK and TIL rather than CAR T-cells, which are more popular for treating hem-malignancies. This is a direct reflection of the challenges associated with CAR T infiltration and persistence in solid tumors. Our analyses indicate that annual IEC-CTs registrations will double by 2025. We anticipate the increase in cellular therapy options will demand an organized response, including adequate logistical planning and policy implementation in response to the landscape changes in clinical oncology during the upcoming years.[Table: see text]

Smartphone based on-chip fluorescence imaging and capillary flow velocity measurement for detecting ROR1+ cancer cells from buffy coat blood samples on dual-layer paper microfluidic chip

Diagnosis of hematological cancer requires complete white blood cell count, followed by flow cytometry with multiple markers, and cytology. It requires substantial time and specialized training. A dual-layer paper microfluidic chip was developed as a quicker, low-cost, and field-deployable alternative to detect ROR1+ (receptor tyrosine-like orphan receptor one) cancer cells from the undiluted and untreated buffy coat blood samples. The first capture layer consisted of a GF/D glass fiber substrate, preloaded with cancer specific anti-ROR1 conjugated fluorescent particles to its center for cancer cell capture and direct smartphone fluorescence imaging. The second flow layer was comprised of a grade 1 cellulose chromatography paper with wax-printed four channels for wicking and capillary flow-based detection. The flow velocity was used as measure of antigen concentration in the buffy coat sample. In this manner, intact cells and their antigens were separated and independently analyzed by both imaging and flow velocity analyses. A custom-made smartphone-based fluorescence microscope and automated image processing and particle counter software were developed to enumerate particles on paper, with the limit of detection of 1 cell/μL. Flow velocity analysis showed even greater sensitivity, with the limit of detection of 0.1 cells/μL in the first 6 s of assay. Comparison with capillary flow model revealed great alignment with experimental data and greater correlation to viscosity than interfacial tension. Our proposed device is able to capture and on-chip image ROR1+ cancer cells within a complex sample matrix (buffy coat) while simultaneously quantifying cell concentration in a point-of-care manner.

Phase I Trial: Cirmtuzumab Inhibits ROR1 Signaling and Stemness Signatures in Patients with Chronic Lymphocytic Leukemia

Cirmtuzumab is a humanized monoclonal antibody (mAb) that targets ROR1, an oncoembryonic orphan receptor for Wnt5a found on cancer stem cells (CSCs). Aberrant expression of ROR1 is seen in many malignancies and has been linked to Rho-GTPase activation and cancer stem cell self-renewal. For patients with chronic lymphocytic leukemia (CLL), self-renewing, neoplastic B cells express ROR1 in 95% of cases. High-level leukemia cell expression of ROR1 is associated with an unfavorable prognosis. We conducted a phase 1 study involving 26 patients with progressive, relapsed, or refractory CLL. Patients received four biweekly infusions, with doses ranging from 0.015 to 20 mg/kg. Cirmtuzumab had a long plasma half-life and did not have dose-limiting toxicity. Inhibition of ROR1 signaling was observed, including decreased activation of RhoA and HS1. Transcriptome analyses showed that therapy inhibited CLL stemness gene expression signatures in vivo. Cirmtuzumab is safe and effective at inhibiting tumor cell ROR1 signaling in patients with CLL.

Axicabtagene Ciloleucel CAR T-Cell Therapy in Refractory Large B-Cell Lymphoma

BACKGROUND

In a phase 1 trial, axicabtagene ciloleucel (axi-cel), an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy, showed efficacy in patients with refractory large B-cell lymphoma after the failure of conventional therapy.

METHODS

In this multicenter, phase 2 trial, we enrolled 111 patients with diffuse large B-cell lymphoma, primary mediastinal B-cell lymphoma, or transformed follicular lymphoma who had refractory disease despite undergoing recommended prior therapy. Patients received a target dose of 2×106 anti-CD19 CAR T cells per kilogram of body weight after receiving a conditioning regimen of low-dose cyclophosphamide and fludarabine. The primary end point was the rate of objective response (calculated as the combined rates of complete response and partial response). Secondary end points included overall survival, safety, and biomarker assessments.

RESULTS

Among the 111 patients who were enrolled, axi-cel was successfully manufactured for 110 (99%) and administered to 101 (91%). The objective response rate was 82%, and the complete response rate was 54%.With a median follow-up of 15.4 months, 42% of the patients continued to have a response, with 40% continuing to have a complete response. The overall rate of survival at 18 months was 52%. The most common adverse events of grade 3 or higher during treatment were neutropenia (in 78% of the patients), anemia (in 43%), and thrombocytopenia (in 38%). Grade 3 or higher cytokine release syndrome and neurologic events occurred in 13% and 28% of the patients, respectively. Three of the patients died during treatment. Higher CAR T-cell levels in blood were associated with response.

CONCLUSIONS

In this multicenter study, patients with refractory large B-cell lymphoma who received CAR T-cell therapy with axi-cel had high levels of durable response, with a safety profile that included myelosuppression, the cytokine release syndrome, and neurologic events. (Funded by Kite Pharma and the Leukemia and Lymphoma Society Therapy Acceleration Program; ZUMA-1 ClinicalTrials.gov number, NCT02348216 .).

A Challenging Pie to Splice: Drugging the Spliceosome

Since its discovery in 1977, the study of alternative RNA splicing has revealed a plethora of mechanisms that had never before been documented in nature. Understanding these transitions and their outcome at the level of the cell and organism has become one of the great frontiers of modern chemical biology. Until 2007, this field remained in the hands of RNA biologists. However, the recent identification of natural product and synthetic modulators of RNA splicing has opened new access to this field, allowing for the first time a chemical-based interrogation of RNA splicing processes. Simultaneously, we have begun to understand the vital importance of splicing in disease, which offers a new platform for molecular discovery and therapy. As with many natural systems, gaining clear mechanistic detail at the molecular level is key towards understanding the operation of any biological machine. This minireview presents recent lessons learned in this emerging field of RNA splicing chemistry and chemical biology.

L-carnitine for pegylated-l-asparaginase induced hepatotoxicity

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Background: Pegylated-L-asparaginase (PEG-Asp) treatment causes severe hepatoxicity in about 25% of adults. Two case reports suggest that L-carnitine may rapidly reverse PEG-Asp-induced hepatotoxicity. Methods: We retrospectively analyzed data from 11 consecutive patients from 3 centers receiving L-carnitine for PEG-Asp-related hepatotoxicity from 4/2014 to 4/2016. Eligible adults received L-carnitine for hepatotoxicity probably or definitely related to PEG-Asp. Total bilirubin (Tbili), ALT, or AST stabilization was defined as a variation within 10% from baseline maintained for 3 days. Improvement was defined as a decrease of ≥10% the prior day maintained for 3 days. Liver imaging included CT scans or ultrasounds. Results: The majority of patients were male, 91% (Table 1). Imaging on 7 patients showed hepatic steatosis in 2 (29%) prior to PEG-Asp and 5 (71%) after PEG-Asp. Median peak Tbili, ALT, and AST were 15.4 mg/dL (2.3-27.58), 194 IU/L (120-1491), and 119 IU/L (52-1064), respectively. Median days from hyperbilirubinemia to L-carnitine initiation was 4 (1-13). Median L-carnitine dose was 2,000 mg/day (1,880-4,450). Median days until Tbili, AST, and ALT improvement were 6.5 (4-14), 4 (2-19), and 3.5 (1-8), respectively. Median days until Tbili normalization was 34 (4-52). Improvement in Tbili, ALT, and AST within 8 days of L-carnitine was seen in 5, 19, and 11 patients, respectively. No adverse events were attributable to L-carnitine. Conclusions: L-carnitine for PEG-Asp-induced hepatotoxicity was safe and associated with stabilization and improvement in transaminitis and, to a lesser extent, hyperbilirubinemia. See table. [Table: see text]

Updated results from ZUMA-3, a phase 1/2 study of KTE-C19 chimeric antigen receptor (CAR) T cell therapy, in adults with high-burden relapsed/refractory acute lymphoblastic leukemia (R/R ALL)

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Background: Promising results have been observed with KTE-C19, an anti-CD19 CAR T cell therapy, in refractory aggressive NHL in the ZUMA-1 trial (Blood 2016;128:LBA-6). We present here updated results from the ZUMA-3 phase 1 trial of KTE-C19 in adult patients (pts) with R/R ALL. Methods: Adult (≥18 y) pts with R/R ALL (Ph+ eligible), ≥25% bone marrow (BM) blasts, adequate organ function and ECOG status 0-1 received 1 or 2×106 CAR T cells/kg after conditioning with cyclophosphamide + fludarabine. Phase 1 primary endpoint is incidence of dose-limiting toxicity (DLT). Secondary endpoints include efficacy outcomes and biomarker associations. Results: As of Nov 1, 2016, 11 pts were enrolled; 10 received KTE-C19. One pt had a serious adverse event (SAE) prior to dosing and was not treated. KTE-C19 was successfully manufactured in all pts across a broad range of baseline absolute lymphocyte counts in 6 days in a centralized facility, with an approximate 2-week turnaround time. Pts were 60% men with 1-4 prior lines of therapy and high disease burden (median, 70% BM blasts). No pt (0/3) experienced a DLT at the 2×106 dose. Phase 1 was expanded to 6 pts at the same dose; 1 grade (Gr) 5 AE (multiorgan failure due to cytokine release syndrome [CRS]) was observed. Subsequent pts (4) received 1×106 CAR T cells/kg. Overall, the most common Gr≥3 AEs were cytopenias (80%), febrile neutropenia (50%), pyrexia (40%), and transaminitis (40%). Gr≥3 CRS and neurologic events (NEs) were reported in 20% and 40% of pts, respectively. Cerebral edema was not observed. All CRS (except Gr5) and 5 of 6 NEs (1 Gr3 ongoing at cut-off) resolved. Of the 8 efficacy evaluable pts, 6 achieved an MRD-negative (MRD–) complete response (CR, or CR + partial or incomplete hematopoietic recovery). Updated results will include additional pt follow-up and biomarker data. Conclusions: No DLTs were observed with KTE-C19 in adult pts with high BM disease burden; one pt had G5 CRS after the DLT cohort. Manufacturing was successful in all pts; most pts achieved an MRD– CR. Based on these results, ZUMA-3 continues to enroll pts with additional measures implemented to further enhance safety. Clinical trial information: NCT02614066.

Targeting the CXCR4 pathway using a novel anti-CXCR4 IgG1 antibody (PF-06747143) in chronic lymphocytic leukemia

BACKGROUND

The CXCR4-CXCL12 axis plays an important role in the chronic lymphocytic leukemia (CLL)-microenvironment interaction. Overexpression of CXCR4 has been reported in different hematological malignancies including CLL. Binding of the pro-survival chemokine CXCL12 with its cognate receptor CXCR4 induces cell migration. CXCL12/CXCR4 signaling axis promotes cell survival and proliferation and may contribute to the tropism of leukemia cells towards lymphoid tissues and bone marrow. Therefore, we hypothesized that targeting CXCR4 with an IgG1 antibody, PF-06747143, may constitute an effective therapeutic approach for CLL.

METHODS

Patient-derived primary CLL-B cells were assessed for cytotoxicity in an in vitro model of CLL microenvironment. PF-06747143 was analyzed for cell death induction and for its potential to interfere with the chemokine CXCL12-induced mechanisms, including migration and F-actin polymerization. PF-06747143 in vivo efficacy was determined in a CLL murine xenograft tumor model.

RESULTS

PF-06747143, a novel-humanized IgG1 CXCR4 antagonist antibody, induced cell death of patient-derived primary CLL-B cells, in presence or absence of stromal cells. Moreover, cell death induction by the antibody was independent of CLL high-risk prognostic markers. The cell death mechanism was dependent on CXCR4 expression, required antibody bivalency, involved reactive oxygen species production, and did not require caspase activation, all characteristics reminiscent of programmed cell death (PCD). PF-06747143 also induced potent B-CLL cytotoxicity via Fc-driven antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity activity (CDC). PF-06747143 had significant combinatorial effect with standard of care (SOC) agents in B-CLL treatment, including rituximab, fludarabine (F-ara-A), ibrutinib, and bendamustine. In a CLL xenograft model, PF-06747143 decreased tumor burden and improved survival as a monotherapy, and in combination with bendamustine.

CONCLUSIONS

We show evidence that PF-06747143 has biological activity in CLL primary cells, supporting a rationale for evaluation of PF-06747143 for the treatment of CLL patients.

Targeting the CXCR4 pathway using a novel anti-CXCR4 IgG1 antibody (PF-06747143) in chronic lymphocytic leukemia

BACKGROUND

The CXCR4-CXCL12 axis plays an important role in the chronic lymphocytic leukemia (CLL)-microenvironment interaction. Overexpression of CXCR4 has been reported in different hematological malignancies including CLL. Binding of the pro-survival chemokine CXCL12 with its cognate receptor CXCR4 induces cell migration. CXCL12/CXCR4 signaling axis promotes cell survival and proliferation and may contribute to the tropism of leukemia cells towards lymphoid tissues and bone marrow. Therefore, we hypothesized that targeting CXCR4 with an IgG1 antibody, PF-06747143, may constitute an effective therapeutic approach for CLL.

METHODS

Patient-derived primary CLL-B cells were assessed for cytotoxicity in an in vitro model of CLL microenvironment. PF-06747143 was analyzed for cell death induction and for its potential to interfere with the chemokine CXCL12-induced mechanisms, including migration and F-actin polymerization. PF-06747143 in vivo efficacy was determined in a CLL murine xenograft tumor model.

RESULTS

PF-06747143, a novel-humanized IgG1 CXCR4 antagonist antibody, induced cell death of patient-derived primary CLL-B cells, in presence or absence of stromal cells. Moreover, cell death induction by the antibody was independent of CLL high-risk prognostic markers. The cell death mechanism was dependent on CXCR4 expression, required antibody bivalency, involved reactive oxygen species production, and did not require caspase activation, all characteristics reminiscent of programmed cell death (PCD). PF-06747143 also induced potent B-CLL cytotoxicity via Fc-driven antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity activity (CDC). PF-06747143 had significant combinatorial effect with standard of care (SOC) agents in B-CLL treatment, including rituximab, fludarabine (F-ara-A), ibrutinib, and bendamustine. In a CLL xenograft model, PF-06747143 decreased tumor burden and improved survival as a monotherapy, and in combination with bendamustine.

CONCLUSIONS

We show evidence that PF-06747143 has biological activity in CLL primary cells, supporting a rationale for evaluation of PF-06747143 for the treatment of CLL patients.

hBfl-1/hNOXA Interaction Studies Provide New Insights on the Role of Bfl-1 in Cancer Cell Resistance and for the Design of Novel Anticancer Agents

Upregulation of antiapoptotic Bcl-2 proteins in certain tumors confers cancer cell resistance to chemotherapy or radiations. Members of the antiapoptotic Bcl-2 proteins, including Bcl-2, Mcl-1, Bcl-xL, Bcl-w, and Bfl-1, inhibit apoptosis by selectively binding to conserved α-helical regions, named BH3 domains, of pro-apoptotic proteins such as Bim, tBid, Bad, or NOXA. Five antiapoptotic proteins have been identified that interact with various selectivity with BH3 containing pro-apoptotic counterparts. Cancer cells present various and variable levels of these proteins, making the design of effective apoptosis based therapeutics challenging. Recently, BH3 profiling was introduced as a method to classify cancer cells based on their ability to resist apoptosis following exposure to selected BH3 peptides. However, these studies were based on binding affinities measured with model BH3 peptides and Bcl-2-proteins taken from mouse sequences. While the majority of these interactions are conserved between mice and humans, we found surprisingly that human NOXA binds to human Bfl-1 potently and covalently via conserved Cys residues, with over 2 orders of magnitude increased affinity over hMcl-1. Our data suggest that some assumptions of the original BH3 profiling need to be revisited and that perhaps further targeting efforts should be redirected toward Bfl-1, for which no suitable specific inhibitors or pharmacological tools have been reported. In this regard, we also describe the initial design and characterizations of novel covalent BH3-based agents that potently target Bfl-1. These molecules could provide a novel platform on which to design effective Bfl-1 targeting therapeutics.

Selectivity in Small Molecule Splicing Modulation

The dysregulation of RNA splicing is a molecular hallmark of disease, including different and often complex cancers. While gaining recognition as a target for therapeutic discovery, understanding the complex mechanisms guiding RNA splicing remains a challenge for chemical biology. The discovery of small molecule splicing modulators has recently enabled an evaluation of the mechanisms of aberrant splicing. We now report on three unique features within the selectivity of splicing modulators. First, we provide evidence that structural modifications within a splicing modulator can alter the splicing of introns in specific genes differently. These studies indicate that structure activity relationships not only have an effect on splicing activity but also include specificity for specific introns within different genes. Second, we find that these splicing modulators also target the mRNAs encoding components of the spliceosome itself. Remarkably, this effect includes the genes for the SF3B complex, a target of pladienolide B and related splicing modulators. Finally, we report on the first observation of a temporal phenomenon associated with small molecule splicing modulation. Combined, these three observations provide an important new perspective for the exploration of splicing modulation in terms of both future medicinal chemistry programs as well as understanding the key facets underlying its timing.

Clinical Practice Recommendations for Use of Allogeneic Hematopoietic Cell Transplantation in Chronic Lymphocytic Leukemia on Behalf of the Guidelines Committee of the American Society for Blood and Marrow Transplantation

We sought to establish clinical practice recommendations to redefine the role of allogeneic hematopoietic cell transplantation (allo-HCT) for patients with chronic lymphocytic leukemia (CLL) in an era of highly active targeted therapies. We performed a systematic review to identify prospective randomized controlled trials comparing allo-HCT against novel therapies for treatment of CLL at various disease stages. In the absence of such data, we invited physicians with expertise in allo-HCT and/or CLL to participate in developing these recommendations. We followed the Grading of Recommendations Assessment, Development and Evaluation methodology. For standard-risk CLL we recommend allo-HCT in the absence of response or if there is evidence of disease progression after B cell receptor (BCR) inhibitors. For high-risk CLL an allo-HCT is recommended after failing 2 lines of therapy and showing an objective response to BCR inhibitors or to a clinical trial. It is also recommended for patients who fail to show an objective response or progress after BCR inhibitors and receive BCL-2 inhibitors, regardless of whether an objective response is achieved. For Richter transformation, we recommend allo-HCT upon demonstration of an objective response to anthracycline-based chemotherapy. A reduced-intensity conditioning regimen is recommended whenever indicated. These recommendations highlight the rapidly changing treatment landscape of CLL. Newer therapies have disrupted prior paradigms, and allo-HCT is now relegated to later stages of relapsed or refractory CLL.

Acute Lymphoblastic Leukemia, Version 2.2015

Treatment of acute lymphoblastic leukemia (ALL) continues to advance, as evidenced by the improved risk stratification of patients and development of newer treatment options. Identification of ALL subtypes based on immunophenotyping and cytogenetic and molecular markers has resulted in the inclusion of Philadelphia-like ALL and early T-cell precursor ALL as subtypes that affect prognosis. Identification of Ikaros mutations has also emerged as a prognostic factor. In addition to improved prognostication, treatment options for patients with ALL have expanded, particularly with regard to relapsed/refractory ALL. Continued development of second-generation tyrosine kinase inhibitors and the emergence of immunotherapy, including blinatumomab and chimeric antigen receptor T-cell therapy, have improved survival. Furthermore, incorporation of minimal residual disease (MRD) monitoring has shown insight into patient outcomes and may lead to treatment modification or alternative treatment strategies in select populations. This excerpt focuses on the sections of the ALL guidelines specific to clinical presentation and diagnosis, treatment of relapsed/refractory ALL, and incorporation of MRD monitoring. To view the most recent complete version of these guidelines, visit NCCN.org.

A Carbohydrate-Derived Splice Modulator

Small-molecule splice modulators have recently been recognized for their clinical potential for diverse cancers. This, combined with their use as tools to study the importance of splice-regulated events and their association with disease, continues to fuel the discovery of new splice modulators. One of the key challenges found in the current class of materials arises from their instability, where rapid metabolic degradation can lead to off-target responses. We now describe the preparation of bench-stable splice modulators by adapting carbohydrate motifs as a central scaffold to provide rapid access to potent splice modulators.

Ulocuplumab (BMS-936564 / MDX1338): a fully human anti-CXCR4 antibody induces cell death in chronic lymphocytic leukemia mediated through a reactive oxygen species-dependent pathway

The CXCR4 receptor (Chemokine C-X-C motif receptor 4) is highly expressed in different hematological malignancies including chronic lymphocytic leukemia (CLL). The CXCR4 ligand (CXCL12) stimulates CXCR4 promoting cell survival and proliferation, and may contribute to the tropism of leukemia cells towards lymphoid tissues. Therefore, strategies targeting CXCR4 may constitute an effective therapeutic approach for CLL. To address that question, we studied the effect of Ulocuplumab (BMS-936564), a fully human IgG4 anti-CXCR4 antibody, using a stroma--CLL cells co-culture model. We found that Ulocuplumab (BMS-936564) inhibited CXCL12 mediated CXCR4 activation-migration of CLL cells at nanomolar concentrations. This effect was comparable to AMD3100 (Plerixafor--Mozobil), a small molecule CXCR4 inhibitor. However, Ulocuplumab (BMS-936564) but not AMD3100 induced apoptosis in CLL at nanomolar concentrations in the presence or absence of stromal cell support. This pro-apoptotic effect was independent of CLL high-risk prognostic markers, was associated with production of reactive oxygen species and did not require caspase activation. Overall, these findings are evidence that Ulocuplumab (BMS-936564) has biological activity in CLL, highlight the relevance of the CXCR4-CXCL12 pathway as a therapeutic target in CLL, and provide biological rationale for ongoing clinical trials in CLL and other hematological malignancies.

Intratumoral injection of Ad-ISF35 (Chimeric CD154) breaks tolerance and induces lymphoma tumor regression

Ad-ISF35, an adenovirus vector encoding a membrane-bound engineered CD154 chimeric protein (ISF35), induces complete A20 lymphoma tumor regression in mice after intratumoral direct injection (IDI). Ad-ISF35 induced durable local and systemic antitumor responses associated with a rapid tumor infiltration of macrophages and neutrophils as well as increased levels of proinflammatory cytokines in the tumor microenvironment. Ad-ISF35 IDI transduced preferentially fibroblasts and macrophages present in the tumor microenvironment, and ISF35 protein expression was observed in only 0.25% of cells present in the tumor. Moreover, Ad-ISF35 IDI induced upregulation of CD40 in tumor and immune regulatory cells, including those that did not express ISF35, suggesting the presence of a strong bystander effect. These responses resulted in the generation of IFN-γ-secreting cytotoxic lymphocytes and the production of specific cytotoxic antibodies against lymphoma cells. Overall, cellular immune therapy based on ISF35 induced phenotypic changes in the tumor cells and tumor microenvironment that were associated with a break in tumor immune tolerance and a curative antitumor effect in this lymphoma mouse model. Our data highlight the potential activity that modulation of costimulatory signaling has in cancer therapy.

Targeting the spliceosome in chronic lymphocytic leukemia with the macrolides FD-895 and pladienolide-B

RNA splicing plays a fundamental role in human biology. Its relevance in cancer is rapidly emerging as demonstrated by spliceosome mutations that determine the prognosis of patients with hematologic malignancies. We report studies using FD-895 and pladienolide-B in primary leukemia cells derived from patients with chronic lymphocytic leukemia and leukemia-lymphoma cell lines. We found that FD-895 and pladienolide-B induce an early pattern of mRNA intron retention - spliceosome modulation. This process was associated with apoptosis preferentially in cancer cells as compared to normal lymphocytes. The pro-apoptotic activity of these compounds was observed regardless of poor prognostic factors such as Del(17p), TP53 or SF3B1 mutations and was able to overcome the protective effect of culture conditions that resemble the tumor microenvironment. In addition, the activity of these compounds was observed not only in vitro but also in vivo using the A20 lymphoma murine model. Overall, these findings give evidence for the first time that spliceosome modulation is a valid target in chronic lymphocytic leukemia and provide an additional rationale for the development of spliceosome modulators for cancer therapy.

Potent fluorinated agelastatin analogues for chronic lymphocytic leukemia: design, synthesis, and pharmacokinetic studies

Chronic lymphocytic leukemia (CLL) is the most common lymphoid neoplasia in Western societies and is currently incurable. Multiple treatment options are practiced, but the available small molecule drugs suffer from dose-limiting toxicity and undesirable side effects. The need for new, less toxic treatments is a pressing concern. Here, we demonstrate that (-)-agelastatin A (1a), a pyrrole-imidazole alkaloid obtained from a marine sponge, exhibits potent in vitro activity against primary cell lines of CLL and disclose the synthesis of several analogues that are equipotent or exceed the potency of the natural product. The novel synthetic analogue, 13-debromo-13-trifluoromethyl agelastatin A (1j), showed higher activity than the natural product when tested against the same cell lines and is the most potent agelastatin derivative reported to date. A detailed in vitro structure-activity relationship of 1a in CLL compared to that of 22 synthetic analogues is described along with preliminary in vivo pharmacokinetic and metabolism studies on the most potent compounds.

Lenalidomide and rituximab for the initial treatment of patients with chronic lymphocytic leukemia: a multicenter clinical-translational study from the chronic lymphocytic leukemia research consortium

PURPOSE

Lenalidomide is an immunomodulatory agent with therapeutic activity in chronic lymphocytic leukemia (CLL). In preclinical models, lenalidomide acted synergistically with rituximab. The CLL Research Consortium initiated a phase II study to evaluate this combination in treatment-naive patients.

PATIENTS AND METHODS

Lenalidomide was initiated at 2.5 mg/day and was escalated based on treatment tolerability to a maximum of 10 mg/day, for 21 days/cycle, for a maximum of seven cycles. Rituximab was administered at the end of cycle 1 and was continued for seven cycles. Patients received allopurinol and aspirin for prophylaxis.

RESULTS

Sixty-nine patients enrolled onto one of two age-specific strata; patients' median age was 56 and 70 years for arms A and B, respectively. Patients in the older-patient stratum more frequently had elevated serum beta-2 microglobulin levels, high-risk Rai stage, and were less likely to complete the maximum planned therapy. Adverse events were similar in the two arms. Nonhematologic toxicity was predominantly at grade 1/2, and neutropenia was the most common hematologic adverse event. The response rate for arm A was 95%, with 20% complete responses (CRs) and 20% nodular partial responses. Of arm B patients, 78% achieved a response, of which 11% were CRs. Median progression-free survival (PFS) was 19 months for the younger cohort and 20 months for the older cohort.

CONCLUSION

Intrapatient dose-escalation was safe. The majority of patients reached the maximum lenalidomide dose and experienced a response to a defined seven-cycle course of lenalidomide and rituximab therapy. Despite differences in baseline characteristics and the response rate between the two strata, the PFS did not differ.

Stabilized cyclopropane analogs of the splicing inhibitor FD-895

Targeting the spliceosome with small molecule inhibitors provides a new avenue to target cancer by intercepting alternate splicing pathways. Although our understanding of alternate mRNA splicing remains poorly understood, it provides an escape pathway for many cancers resistant to current therapeutics. These findings have encouraged recent academic and industrial efforts to develop natural product spliceosome inhibitors, including FD-895 (1a), pladienolide B (1b), and pladienolide D (1c), into next-generation anticancer drugs. The present study describes the application of semisynthesis and total synthesis to reveal key structure-activity relationships for the spliceosome inhibition by 1a. This information is applied to deliver new analogs with improved stability and potent activity at inhibiting splicing in patient derived cell lines.

Ofatumumab in combination with high-dose methylprednisolone for the treatment of patients with relapsed or refractory chronic lymphocytic leukemia

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Background: We performed a phase II, single-arm, clinical trial evaluating ofatumumab in combination with HDMP for the treatment of patients with relapsed or refractory CLL. Methods: Patients received ofatumumab at the dose of 1,000 mg weekly (half the conventional dose) for 12 weeks, without monthly maintenance doses. The HDMP dose was 1,000 mg/m2for 3 days of each of 3 monthly cycles. Prophylactic medications included acyclovir, bactrim, fluconazole, and allopurinol. Results: 21 patients were enrolled at a single center. The median age was 63 years (range 46–76). The median number of prior therapies was 3. 24% had unfavorable cytogenetics (Del 17p or Del 11q) and 76% had CLL cells that expressed unmutated IgVH genes or high levels of ZAP-70. 24% were fludarabine-refractory. Treatment was well tolerated. The majority of adverse events were grade 1 or 2, including insomnia, anxiety, fatigue, and infusion reactions. There were no grade 4 toxicities.19% of patients had grade 3 neutropenia, and 5% had grade 3 thrombocytopenia. Other grade 3 toxicities were hyperglycemia (71%), non-melanoma skin cancer and other skin lesions (19%), as well as acute coronary syndrome, atrial fibrillation, renal calculi, pneumonia, and hypocalcemia (1 patient each). Responses were assessed two months after completion of therapy. The overall response rate was 81% (17/21) with 5% CR (1/21), 10% nodular PR (2/21), 67% PR (14/21), 14% SD (3/21), and 5% PD. The median follow-up time was 12 months (range 5-23). The median progression-free survival (PFS) time was 9.1 months (95%CI: 7.5-NA) and the median treatment-free survival (TFS) was 11.5 months (95%CI: 10.0-NA). Patients with Del 17p or Del 11q had a significantly lower overall response rate (p-value <0.001, fisher’s exact test). Conclusions: The combination of HDMP and ofatumumab is an effective, tolerable, non-myelosuppressive treatment regimen. We observed a higher ORR and longer PFS than those previously reported with single agent mAb. This regimen may be useful for patients who are unable to tolerate more aggressive, myelosuppressive therapies, or have not responded to other treatments.

Concurrent chemoradiation (CChRT) with bi-weekly docetaxel and cisplatin and thoracic radiotherapy for stage III non-small cell lung cancer (NSCLC): A phase II study from the Galician Lung Cancer Group

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Background: CChRT is recommended as the evidence-based approach for the management of patients (p) with locally advanced stage III NSCLC and a good performance status, although a clearly superior regimen has not been identified. The aim of our study was to evaluate the effectiveness and toxicities of CChRT with bi-weekly docetaxel (D) and cisplatin (C) and thoracic radiotherapy. Methods: 50 p with histologically confirmed inoperable locally advanced NSCLC, stage IIIAN2/IIIB (no pleural T4), PS 0-1 and adequate lung function (FEV1 > 1.1, V20 < 25%) were included: one cycle of D 75 mg/m2 on day 1 and C 40 mg/m2 days 1-2 followed at 21 days by CChRT with bi-weekly D 40 mg/m2 and C 40 mg/m2 for four courses, during conformal thoracic radiotherapy (66 Gys, 180 cGy/day). The primary objective was overall survival (OS); secondary objectives were progression free survival (PFS), response rate (RR) and toxicity. Median follow-up: 14,5 months. Results: The p characteristics were: mean age 59,1 years (34-75); male/female 44/6; squamous/adeno/large cell carcinoma: 52%/34%/14%; stage IIIAN2 14 p (28%) and stage IIIB 36 p (72%). All p were evaluable for response and toxicity. RR: 4 CR, 36 PR (RR 80%; 95% CI:69-91), 4 SD (8%) and 6 PD (12%). The median PFS was 13 months (95% CI:8-18) and median OS was 19 months (95% CI:14-24). The PFS and OS at 1/2 years were 52%/30% and 79%/40% respectively. A total of 50 cycles of D-C induction chemotherapy were given; main toxicities (NCI-CTC 3.0) per p Grade (g) 1-2/3-4 (%) were as follows: neutropenia 2/16; anemia 12/0; nausea/vomiting 28/2; diarrhea 22/4; there were two episodes of febrile neutropenia. Main toxicities per p in CChRT (D-C doses: 192, 3.8 per p; mean doses RT: 64,6 Gys) were g1-2/3 (%): neutropenia 28/6; anemia 60/0; esophagitis 52/4 and pneumonitis 34/0; there were four episodes of hospitalization: febrile neutropenia, 2 p and g3 esophagitis, 2 p. Conclusions: CChRT with bi-weekly docetaxel and cisplatin and thoracic radiotherapy is a feasible treatment option for inoperable locally advanced stage III NSCLC, showing good clinical efficacy and tolerability with acceptable long-term survival.

Gene immunotherapy of chronic lymphocytic leukemia: a phase I study of intranodally injected adenovirus expressing a chimeric CD154 molecule

New therapies for chronic lymphocytic leukemia (CLL) are needed, particularly those that can eradicate residual disease and elicit anti-CLL immune responses. CD40 ligation on CLL cells, which can be achieved using adenovirus encoding chimeric CD154 (Ad-ISF35), enhances their ability to function as antigen-presenting cells and increases their sensitivity to clearance by immune-effector mechanisms. In this study, we report the results of a first-in-man phase I trial of intranodal direct injection (IDI) of Ad-ISF35 in patients with CLL to evaluate toxicity, safety, and tolerability. Fifteen patients received a single IDI of 1 × 10(10) to 33 × 10(10) Ad-ISF35 viral particles (vp), with a defined maximum tolerated dose as 1 × 10(11) vp. Although the most common adverse events were transient grade 1 to 2 pain at the injection site and flu-like symptoms following IDI, some patients receiving the highest dose had transient, asymptomatic grade 3 to 4 hypophosphatemia, neutropenia, or transaminitis. Increased expression of death receptor, immune costimulatory molecules, and Ad-ISF35 vector DNA was detected in circulating CLL cells. Notably, we also observed preliminary clinical responses, including reductions in leukemia cell counts, lymphadenopathy, and splenomegaly. Six patients did not require additional therapy for more than 6 months, and three achieved a partial remission. In conclusion, Ad-ISF35 IDI was safely delivered in patients with CLLs and induced systemic biologic and clinical responses. These results provide the rationale for phase II studies in CLLs, lymphomas, and CD40-expressing solid tumors.

Autologous hematopoietic stem cell transplantation as an intensive consolidation therapy for adult patients in remission from acute myelogenous leukemia

Autologous peripheral blood stem/progenitor cell transplantation (APBSCT) has been investigated as a potential therapeutic option to improve outcome in patients with acute myelogenous leukemia (AML). However, its optimal role in treatment for adults in remission has not been clearly established. We performed a retrospective analysis on 45 patients aged 21 to 73 years (median 51 years) with de novo AML who underwent APBSCT stratified by age, complete remission status, and cytogenetic risk. The 5-year disease-free survival (DFS) for all patients was 33.9% (95% confidence interval [CI], 20.1%-53.7%) and overall survival (OS) was 43.6% (CI, 29.2%-62.8%). For patients under the age of 60 years, the 5-year DFS for intermediate and high cytogenetic risk was 53.3% (CI, 23.5%-85.6%) and 50.0% (CI, 16.1%-100.0%); the 5-year OS for patients under the age of 60 years with low, intermediate, and high cytogenetic risk was 80.0% (CI, 40.0%-100.0%), 60.0% (CI, 31.2%-90.7%), and 75.0% (CI, 39.0%-100.0%), respectively. For patients over the age of 60 years, the 5-year DFS and OS for intermediate cytogenetic risk was 21.4% (CI, 7.9%-58.4%) and 21.4% (CI, 7.9%-58.4%). The DFS and OS of these patients are comparable to the historic survival of those who underwent allogeneic stem cell transplantation when adjusted by age. In addition, there was no treatment-related mortality (TRM). We conclude that APBSCT is a reasonable and safe intensive consolidation for patients with AML who do not have a suitable HLA-matched donor.

Peripheral blood progenitor cell mobilization with intermediate-dose cyclophosphamide, sequential granulocyte-macrophage-colony-stimulating factor and granulocyte-colony-stimulating factor, and scheduled commencement of leukapheresis in 225 patients undergoing autologous transplantation

BACKGROUND

Interpatient variability in the kinetics of peripheral blood progenitor cell (PBPC) mobilization is commonly seen with conventional chemotherapy-based mobilization regimens. This necessitates the availability of leukapheresis (LP) facilities 7 days a week.

STUDY DESIGN AND METHODS

The efficacy of an approach where LP was invariably commenced on Day 11 after intermediate-dose cyclophosphamide followed by sequential administration of granulocyte-macrophage-colony-stimulating factor (CSF) and granulocyte-CSF (Cy/GM/G) was retrospectively analyzed in 225 consecutive, unselected patients undergoing autologous hematopoietic stem cell transplantation for all diagnoses other than acute leukemia at our center. Cy/GM/G was scheduled to avoid weekend LP.

RESULTS

After Cy/GM/G, a CD34+ cell yield of at least 2.0x10(6) per kg was achieved in 90.7 percent of patients. Optimal yield (OY; >or=5x10(6) or 10x10(6) CD34+ cells/kg depending on diagnosis) was achieved in 67.6 percent of patients. Only three patients (1.3%) required LP on Saturday or Sunday. Febrile neutropenia (FN) was encountered in 5.3 percent. PBPC yield was highest on Day 1 of LP (p<0.001). In multivariate analyses, platelet (PLT) count on Day 1 of LP (PLT-D1LP) was positively associated with achievement of OY (p<0.001). PLT-D1LP and diagnosis of myeloma were associated with a shorter time to achieve a CD34+ cell yield of at least 5x10(6) per kg (p<0.001 and p=0.002, respectively).

CONCLUSION

Cy/GM/G with scheduled LP commencement on Day 11 enables optimal CD34+ cell yields in most patients undergoing autologous transplantation, despite a low risk of FN and avoidance of weekend LP.