Phase I trial of anti-PSMA designer T cells in advanced prostate cancer

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Background: We created chimeric immunoglobulin-T cell receptors (IgTCR) specific for prostate specific membrane antigen (PSMA). When expressed in patient T cells, these “designer T cells” (dTc) specifically kill prostate cancer cells in vitro and in vivo in animal models, with 5/9 (55%) of xenografted mice experiencing complete remissions (Ma et al. Prostate 2004:61:12–25). A phase I clinical trial was approved by the FDA.

Methods: Patient T cells are retrovirally transduced and expanded ex vivo to span dose levels of 10^9 to 10^11 T cells. Patients undergo prior non-myeloablative (NMA) conditioning to create “hematologic space” into which designer T cells are infused for stable engraftment and prolonged in vivo efficacy. Patients are co-administered continuous infusion IL2. Outcomes include Phase Ia goals of safety and Phase Ib goals of establishing an optimal biologic dose in terms of designer T cell engraftment.

Results: Five patients have been treated, three at 10^9 and two at 10^10 cell dose levels. Excellent T cell modifications of 30%-60% were obtained. After NMA conditioning, T cells were infused. Stable engraftments of 1%-20% post-recovery at one month after T cell infusion, thus affirming one of the study end-points. Patients experienced neutropenic fever after conditioning, but no designer T cell-related toxicities. Two patients had partial responses with PSA reductions of 50 and 70% in the two months following treatment with projected benefits of 4 months gain of time to return to starting PSA levels. Results will be updated at the conference.

Conclusions: A new approach to adoptive immune therapy in metastatic prostate cancer has been devised with encouraging early results. Patients are being actively recruited. This clinical trial received partial funding from the US Army/DOD. Preclinical work was supported by the Prostate Cancer Foundation.

No significant financial relationships to disclose.

Phase I trial of advanced generation anti-CEA designer T cells in gastrointestinal and breast cancers

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Background: We created “designer T cells” by retroviral gene therapy to express chimeric immunoglobulin-T cell receptors (IgTCR) with specificity for carcinoembryonic antigen (CEA). Our previous Phase I trial with 1st generation (1st gen) designer T cells was well tolerated with proof-of-principle “biologic responses”, but of limited duration. Lab correlates showed modified T cells repeatedly kill tumor targets over 4–7 days but then undergo activation-induced cell death (AICD). We created 2nd gen designer T cells that incorporate CD28 co-stimulation into the IgTCR (IgCD28TCR), suppressing AICD and promoting T cell proliferation on tumor contact with superior tumor responses in vivo (Emtage et al. Clin Cancer Res 2008;14:8112). A Phase I clinical trial was approved under FDA BB-IND 10791. Methods: Patient T cells are modified ex vivo, expanded and then administered in a Phase Ia dose escalation, spanning doses of 10^9 to 10^11 cells. Patients are monitored for safety, pharmacokinetics and response. Results: To date, three subjects enrolled with doses prepared and two were treated. T cells were transduced with equal modification of CD4 helper and CD8 cytotoxic T cells and good ex vivo expansions of 30-fold or more. Cells were infused over 15–30 minutes. Blood clearance was rapid. Dosing was without toxicity but also without responses at this lowest T cell dose level. Results will be updated to include new patients at conference time. Conclusions: The safety of 2nd generation designer T cells is supported in two patients at the lowest T cell dose level. Higher planned doses are 10- to 100-fold more T cells, to be observed for toxicity and where responses may begin to be observed. Funding is from the Office of Orphan Products Development of the FDA.

No significant financial relationships to disclose.

Phase I trial of anti-PSMA designer T-cell autografting in prostate cancer

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Background: We created chimeric immunoglobulin-T cell receptors (IgTCR) specific for prostate specific membrane antigen (PSMA). When expressed in patient T cells, these “designer T cells” specifically kill prostate cancer cells in vitro and in vivo in animal models, with 5/9 (55%) of xenografted mice experiencing complete remissions (Ma et al. Prostate 2004:61:12–25). A Phase I clinical trial was approved by the FDA in metastatic prostate cancers. Methods: Patient T cells are retrovirally transduced and expanded ex vivo to span dose levels of 10^9 to 10^11 T cells. Adapting methods of Dudley, Rosenberg and colleagues, patients undergo prior non-myeloablative (NMA) conditioning to create a “hematologic space” into which the infused designer T cells will stably engraft for prolonged in vivo efficacy. Patients are co-administered continuous infusion IL2. Outcomes will include Phase Ia goals of safety and toxicity and Phase Ib goals of establishing an optimal biologic dose in terms of designer T cell engraftment and tumor response. Results: For the first two patients, excellent T cell modifications of 50–60% were obtained. After NMA conditioning, T cells were infused and stable engraftments of 1–5% were observed post recovery, even at this lowest 10^9 T cell dose level, thus affirming one of the study end-points. The patients had PSA reductions of 50 and 70% in the two months following treatment. Patients experienced neutropenia and lymphopenia after conditioning, but no designer T cell-related toxicities. Results with additional patients will be described in terms of safety, engraftment efficiency and tumor responses. Conclusions: A new approach to adoptive immune therapy in metastatic prostate cancer has been devised. This clinical trial is funded by the US Army/DOD.

No significant financial relationships to disclose.

Percutaneous ultrasound-guided cryoablation of renal tumors using the CIVCO assist positioning system

Cryoablation is emerging as an accepted treatment for small renal tumors. Percutaneous placement of cryoprobes using ultrasound guidance is an attractive option for patients with tumors easily seen with transabdominal ultrasonography; however, the placement of probes using hand-held devices is technically challenging. To improve the accuracy and ease of cryoprobe placement during percutaneous renal cryoablation, we describe the novel application of the CIVCO Assist positioning arm system during these complex procedures.

Robotic-assisted laparoscopic retroperitoneal lymph node dissection

Minimally invasive laparoscopic techniques have been applied to the staging and treatment of testicular cancer during the performance of retroperitoneal lymph node dissection. The da Vinci Surgical System potentially improves the safety and accuracy of this approach. We present what we believe to be the first published description of robotic-assisted retroperitoneal lymph node dissection, which was performed in an 18-year-old man with a mixed germ cell tumor. This case demonstrates the technical feasibility, safety, and accuracy of robotic-assisted retroperitoneal lymph node dissection and expands the role of minimally invasive techniques in urologic oncology.

Henoch-Schönlein purpura presenting with orchitis: a case report and review of the literature

Henoch-Schönlein purpura (HSP) is the most common cause of nonthrombocytopenic purpura in children. The clinical picture is classically a cutaneous purpuric eruption of the legs and buttocks and infrequently the upper torso and extremities. Arthritis, gastrointestinal tract symptoms, and nephritis are other common findings typically associated with the cutaneous findings. We present an unusual case of HSP with scrotal swelling and orchitis.

Priapism associated with routine use of quetiapine: case report and review of the literature

We report a case of priapism occurring in a patient taking a standard daily dose of the atypical antipsychotic quetiapine (Seroquel). To our knowledge, this represents the second published report associating quetiapine with priapism, and the first to associate priapism with routine dosing of the drug. Previously published studies have suggested that alpha-adrenergic blockade may be the mechanism of action for this side effect. We report successful management in this case with cavernosal aspiration followed by intracavernosal injection of phenylephrine.

Testicular torsion in a 68-year-old man

Testicular torsion is a rare, yet often underrecognized, cause of scrotal pain in adult men. Few reports have commented on testicular torsion in the geriatric population. We report a case of a 68-year-old man initially diagnosed with epididymo-orchitis, who, on surgical exploration, was found to have intravaginal testicular torsion. The diagnosis in this patient population is often delayed, leading to poor salvage rates. The use of color Doppler ultrasonography should be strongly considered if the history and physical examination is suggestive of testicular torsion, regardless of patient age.

Computerized Tomography With 3-Dimensional Reconstruction for the Evaluation of Renal Size and Arterial Anatomy in the Living Kidney Donor

PURPOSE

Computerized tomography (CT) with 3-dimensional (3-D) reconstruction has gained acceptance as an imaging study to evaluate living renal donors. We report our experience with this technique in 199 consecutive patients to validate its predictions of arterial anatomy and kidney volumes.

MATERIALS AND METHODS

Between January 1997 and March 2002, 199 living donor nephrectomies were performed at our institution using an open technique. During the operation arterial anatomy was recorded as well as kidney weight in 98 patients and displacement volume in 27. Each donor had been evaluated preoperatively by CT angiography with 3-D reconstruction. Arterial anatomy described by a staff radiologist was compared with intraoperative findings. CT estimated volumes were reported. Linear correlation graphs were generated to assess the reliability of CT volume predictions.

RESULTS

The accuracy of CT angiography for predicting arterial anatomy was 90.5%. However, as the number of renal arteries increased, predictive accuracy decreased. The ability of CT to predict multiple arteries remained high with a positive predictive value of 95.2%. Calculated CT volume and kidney weight significantly correlated (0.654). However, the coefficient of variation index (how much average CT volume differed from measured intraoperative volume) was 17.8%.

CONCLUSIONS

CT angiography with 3-D reconstruction accurately predicts arterial vasculature in more than 90% of patients and it can be used to compare renal volumes. However, accuracy decreases with multiple renal arteries and volume comparisons may be inaccurate when the difference in kidney volumes is within 17.8%.

The mitotoxin, basic fibroblast growth factor-saporin, effectively targets human prostatic carcinoma in an animal model

PURPOSE

The antitumor activity of the mitotoxin basic fibroblast growth factor-saporin (bFGF-SAP) against human prostatic carcinoma DU 145 was examined in athymic nude mice. Therapeutic efficacy was evaluated on the basis of dose, route of administration and treatment schedule.

MATERIALS AND METHODS

Chemical conjugate or recombinant bFGF-SAP (0.02 to 50 micrograms/kg.) was administered by intravenous tail injection, intraperitoneal injection, or local or distal subcutaneous injection beginning 5 days (or 60 to 121 days for large tumor studies) after subcutaneous implantation of DU 145 cells. Tumor growth was monitored as long as 140 days by external caliper measurements.

RESULTS

Recombinant bFGF-SAP, though less cytotoxic than its chemical conjugate form, effectively targeted DU 145 tumors growing as xenografts in nude mice in a dose-dependent manner. Antitumor response to treatment by intravenous, intraperitoneal, or distal subcutaneous injection suggested similar bioavailability of the mitotoxin administered by each route; local subcutaneous injection to the tumor site resulted in statistically better antitumor response. Schedules that included at least 1 bFGF-SAP treatment beyond day 23 increased long-term antitumor efficacy independent of total dose. Moreover, recombinant bFGF-SAP induced dramatic reduction of large, established tumors.

CONCLUSIONS

These studies suggest a therapeutic potential for bFGF receptor-directed toxins in targeting prostate cancer; further, these data suggest that treatment of established tumors (> 3 weeks) results in qualitatively and quantitatively improved tumor responses.

Saporin toxins directed to basic fibroblast growth factor receptors effectively target human ovarian teratocarcinoma in an animal model

BACKGROUND

The antitumor activity of the chemical conjugate and recombinant forms of the mitotoxin basic fibroblast growth factor (bFGF) saporin (SAP) and the bFGF receptor-directed immunotoxin 11A8-SAP against human ovarian teratocarcinoma PA-1 was examined in athymic nude mice. Alternative administration schedules to prolong therapeutic efficacy were explored.

METHODS

Intravenous dosing (0.01-125 micrograms/kg) of chemical conjugate and recombinant bFGF-SAP or 11A8-SAP beginning 5 days after subcutaneous implantation of PA-1 cells was administered by i) weekly injection for 4 weeks, ii) continuous infusion for one week, or iii) daily injection five times a week for 4 weeks.

RESULTS

Weekly injections (31.25 micrograms/kg) of chemical conjugate bFGF-SAP or 11A8-SAP, the latter of which is 25% the molarity of the former, resulted in mean tumor volumes that were, respectively, 35% or 52% of controls (day 30) and 52% or 76% of controls (day 60). Chemical conjugate or recombinant bFGF-SAP administered weekly resulted in mean tumor volumes that were, respectively, 51% or 77% (0.5 microgram/kg) and 42% or 31% (50 micrograms/kg) of controls (day 30). A mean tumor volume of 35% of controls (day 30) and of 49% of controls (day 60) were observed in animals treated by constant infusion of chemical conjugate bFGF-SAP (125 micrograms/kg, total dose). Alternatively, tumors of animals receiving daily injections (125 micrograms/kg, total dose) exhibited a mean volume of 21% of controls (day 30) and prolonged growth inhibition as demonstrated by a mean tumor volume of 22% of controls (day 60).

CONCLUSIONS

These studies suggest a therapeutic potential for bFGF-receptor-directed saporin toxins in the treatment of ovarian teratocarcinoma and the importance of frequency of administration in achieving optimal tumor responses.

Autocrine down-regulation of basic fibroblast growth factor receptors causes mitotoxin resistance in a human melanoma cell line

The ability of melanoma to develop resistance to mitotoxins, growth-factor-directed anti-neoplastic agents that offer potential for the treatment of this highly refractory disease, may limit therapeutic efficacy. To address this problem, we developed a subcloned human melanoma cell line that is resistant to the mitotoxin composed of basic fibroblast growth factor conjugated to the ribosome-inactivating protein saporin. Resistance was caused by autocrine FGF ligands, which down-regulate bFGF receptors and reduce bFGF-saporin binding. Inhibiting the autocrine loop with suramin or with neutralizing antibodies to FGF up-regulated receptors and decreased resistance in vitro. Furthermore, suramin restored sensitivity in resistant tumor xenografts. These results suggest the potential of therapeutic modalities combining agents that neutralize growth factors with receptor-directed mitotoxins for targeting malignant melanoma either to prevent emergence of resistance or to circumvent resistance once it occurs.

Antitumor activity of basic fibroblast growth factor-saporin mitotoxin in vitro and in vivo

Many cancer cell lines express basic fibroblast growth factor (FGF) receptors, making them potential targets for the delivery of FGF-based cytotoxic compounds. To this end, we have investigated the antitumor activity of a novel mitotoxin, Fibroblast Growth Factor-saporin (FGF-SAP), a conjugate of FGF and the ribosome-inactivating protein, saporin. In vitro, FGF-SAP is cytotoxic for human melanoma, teratocarcinoma, and neuroblastoma cells expressing FGF-receptors. Mice treated with FGF-SAP i.v., on a variety of schedules, showed dramatic tumor growth inhibition with minimal toxicity. Thus, FGF-SAP appears to be a well-tolerated and potent antitumor agent. The potential of FGF-targeted cytotoxicity is discussed.