Oligoclonal T Cells Transiently Expand and Express Tim-3 and PD-1 Following Anti-CD19 CAR T Cell Therapy: A Case Report.

Clinical trials of chimeric antigen receptor (CAR) T cells in hematologic malignancy associate remissions with two profiles of CAR T cell proliferation kinetics, which differ based upon costimulatory domain. Additional T cell intrinsic factors that influence or predict clinical response remain unclear. To address this gap, we report the case of a 68-year-old woman with refractory/relapsed diffuse large B cell lymphoma (DLBCL), treated with tisagenlecleucel (anti-CD19), with a CD137 costimulatory domain (4-1BB) on an investigational new drug application (#16944). For two months post-infusion, the patient experienced dramatic regression of subcutaneous nodules of DLBCL. Unfortunately, her CAR T exhibited kinetics unassociated with remission, and she died of DLBCL-related sequelae. Serial phenotypic analysis of peripheral blood alongside sequencing of the ß-peptide variable region of the T cell receptor (TCRß) revealed distinct waves of oligoclonal T cell expansion with dynamic expression of immune checkpoint molecules. One week prior to CAR T cell contraction, T cell immunoglobulin mucin domain 3 (Tim-3) and programmed cell death protein 1 (PD-1) exhibited peak expressions on both the CD8 T cell (Tim-3 ≈ 50%; PD-1 ≈ 17%) and CAR T cell subsets (Tim-3 ≈ 78%; PD-1 ≈ 40%). These correlative observations draw attention to Tim-3 and PD-1 signaling pathways in context of CAR T cell exhaustion.

The addition of sirolimus to the graft-versus-host disease prophylaxis regimen in reduced intensity allogeneic stem cell transplantation for lymphoma: a multicentre randomized trial.

Inhibition of the mechanistic target of rapamycin (mTOR) pathway has clinical activity in lymphoma. The mTOR inhibitor sirolimus has been used in the prevention and treatment of graft-versus-host disease (GVHD) after allogeneic haematopoietic stem cell transplantation (HSCT). A retrospective study suggested that patients with lymphoma undergoing reduced intensity conditioning (RIC) HSCT who received sirolimus as part of their GVHD prophylaxis regimen had a lower rate of relapse. We therefore performed a multicentre randomized trial comparing tacrolimus, sirolimus and methotrexate to standard regimens in adult patients undergoing RIC HSCT for lymphoma in order to assess the possible benefit of sirolimus on HSCT outcome. 139 patients were randomized. There was no difference overall in 2-year overall survival, progression-free survival, relapse, non-relapse mortality or chronic GVHD. However, the sirolimus-containing arm had a significantly lower incidence of grade II-IV acute GVHD (9% vs. 25%, P = 0·015), which was more marked for unrelated donor grafts. In conclusion, the addition of sirolimus for GVHD prophylaxis in RIC HSCT is associated with no increased overall toxicity and a lower risk of acute GVHD, although it does not improve survival; this regimen is an acceptable option for GVHD prevention in RIC HSCT. This trial is registered at clinicaltrials.gov (NCT00928018).

Plerixafor in combination with granulocyte-colony-stimulating factor after chemotherapy increases mobilization efficiency in patients with lymphoma or myeloma: results of a Phase II clinical trial.

BACKGROUND: We tested whether adding plerixafor to G-CSF mobilization after chemotherapy would increase the proportion of patients collecting the target number of CD34+ cells/kg in 1 day of apheresis to >75%. STUDY DESIGN AND METHODS: Autologous stem cell transplant-anticipated multiple myeloma or lymphoma patients were eligible. Patients were mobilized with cyclophosphamide (n=17); DCEP (n=1); R-ICE (n=20); CHOP (n=2); or R-HCVAD (n=5) and given 5 mg/kg/day GCSF starting on Day 2 and increasing to 10 mg/kg/day on Day 6. Plerixafor 240 mg/kg was injected subcutaneously on the day the neutrophil count was more than 1.5 × 10(9) cells/L with apheresis the folllowing day. G-CSF, plerixafor, and apheresis continued daily until 5 × 10(6) (lymphoma) or 10 × 10(6) (myeloma) CD34+ cells/kg were collected. RESULTS: Seventeen myeloma and 28 lymphoma patients enrolled, and 76% collected the target number of CD34+ cells in 1 day. Twelve subjects with median CD34+ counts of 142 × 10(6) cells/L began apheresis without plerixafor and collected 20 × 10(6) CD34+ cells/kg in 1 day. The remaining 33 subjects, with median 11.7 × 10(6) CD34+ cells/L and 5.4 × 10(9) WBC/L, received plerixafor. Plerixafor-treated subjects collected 7.8 × 10(6) CD34+ cells/kg; 22 (67%) collected in 1 day, while 11 (33%) required more than 1 day. Plerixafor was well tolerated, with no serious adverse events. CONCLUSIONS: Plerixafor administration after chemotherapy for autologous stem cell mobilization is feasible, well tolerated, and increases the proportion of subjects collected in a single day compared to mobilization with G-CSF after chemotherapy.

A Randomized Trial of Topical Fibrinogen-Depleted Human Platelet Lysate Treatment of Dry Eye Secondary to Chronic Graft-versus-Host Disease.

Purpose: The purpose of the study was to evaluate, as a pilot trial, safety and tolerability of CAM-101 10% and 30% topical ophthalmic fibrinogen-depleted human platelet lysate (FD hPL) solution in patients with dry eye disease (DED) secondary to graft-versus-host disease (GvHD) after 6 weeks of treatment. Design: A phase I/II, pilot, prospective, multicenter, randomized, double-masked clinical trial. Participants: Patients with DED secondary to GvHD. Methods: Sixty-four adult patients were stratified by "symptom severity" (Ocular Surface Disease Index [OSDI], ocular discomfort Visual Analog Scale (VAS), ocular symptom frequency, and use of artificial tears) and then randomized 1:1:1 to CAM-101 (FD hPL) at 10% or 30% concentration or an electrolyte (Plasma-Lyte A) vehicle control, 1 drop in both eyes, 4 times daily, for 42 days. After 42 days, control patients were offered 42 days of open-label treatment with 30% FD hPL. Main Outcome Measures: Primary outcome safety measures were ocular and systemic adverse events and the number of patients in each group with clinically significant change from normal to abnormal in any ocular findings. Secondary outcomes were changes from baseline to day 42 in ocular discomfort, OSDI, fluorescein corneal staining, and lissamine green conjunctival staining relative to the vehicle control. The ocular symptom frequency was assessed on a 100-point VAS. Results: FD hPL 10% and 30% were safe and well tolerated. Relative to the vehicle control, significant decreases from baseline to day 42 were seen in the FD hPL 30% group with regard to ocular discomfort (mean decrease = -18.04; P = 0.018), frequency of burning/stinging (-20.23; P = 0.022), eye discomfort (-32.97; P < 0.001), eye dryness (-21.61; P = 0.020), pain (-15.12; P = 0.044), photophobia (-24.33; P = 0.0125), and grittiness (-20.08; P = 0.0185). Decreases were also seen for itching and foreign body sensation, though not statistically significant. Improvements were seen in tear breakup time (mean increase = 1.30 seconds; P = 0.082) and the investigator's global evaluation 4-point scale (mean decrease = -0.86; P = 0.026). Corneal fluorescein staining was not improved. The OSDI had a mean decrease of -8.88 compared to the vehicle, although not statistically significant. Conclusions: Fibrinogen-depleted human platelet lysate appears to be well tolerated, with no significant toxicity at concentrations of 10% and 30%. These initial data suggest some efficacy, especially for subjective outcome measures relative to baseline assessments and treatment with the vehicle, but larger studies are needed to confirm these effects.

Improving T-cell expansion and function for adoptive T-cell therapy using ex vivo treatment with PI3Kδ inhibitors and VIP antagonists.

Adoptive therapy with ex vivo-expanded genetically modified antigen-specific T cells can induce remissions in patients with relapsed/refractory cancer. The clinical success of this therapy depends upon efficient transduction and expansion of T cells ex vivo and their homing, persistence and cytotoxicity following reinfusion. Lower rates of ex vivo expansion and clinical response using anti-CD19 chimeric antigen receptor (CAR) T cells have been seen in heavily pretreated lymphoma patients compared with B-cell acute lymphoblastic leukemia patients and motivate the development of novel strategies to enhance ex vivo T cell expansion and their persistence in vivo. We demonstrate that inhibition of phosphatidylinositol 3-kinase δ (PI3Kδ) and antagonism of vasoactive intestinal peptide (VIP) signaling partially inhibits the terminal differentiation of T cells during anti-CD3/CD28 bead-mediated expansion (mean, 54.4% CD27+CD28+ T cells vs 27.4% in control cultures; P < .05). This strategy results in a mean of 83.7% more T cells cultured from lymphoma patients in the presence of PI3Kδ and VIP antagonists, increased survival of human T cells from a lymphoma patient in a murine xenograft model, enhanced cytotoxic activity of antigen-specific human CAR T cells and murine T cells against lymphoma, and increased transduction and expansion of anti-CD5 human CAR T cells. PI3Kδ and VIP antagonist-expanded T cells from lymphoma patients show reduced terminal differentiation, enhanced polyfunctional cytokine expression, and preservation of costimulatory molecule expression. Taken together, synergistic blockade of these pathways is an attractive strategy to enhance the expansion and functional capacity of ex vivo-expanded cancer-specific T cells.