Autologous Cellular Immunotherapy Research Articles

Survival outcomes for African-American (AA) vs matched Caucasian (CAU) patients (pts) with metastatic castration-resistant prostate cancer (mCRPC) treated with sipuleucel-T (sip-T).

192 Background: Prostate cancer risk and mortality is higher in AA vs CAU men. In an analysis of three phase 3 mCRPC trials, AA pts appear to derive greater survival benefit with sip-T, an autologous cellular immunotherapy for asymptomatic/minimally symptomatic mCRPC. AA pts on sip-T had a 30.7-month (mo) median overall survival (OS) benefit vs control (AUA 2012 P953), in contrast to a 4.1-mo OS benefit with sip-T vs control for all pts in IMPACT (NEJM 2010;363:411). As the prior analysis did not adjust for baseline differences between races, we matched AA to CAU pts on sip-T to better assess racial differences in sip-T benefit and cumulative antigen presenting cell (APC) activation, which correlates with OS (CII 2013;62:137). Methods: Data were from phase 3 mCRPC trials that randomized pts 2:1 to sip-T or control (D9901 [NCT00005947]; D9902A [NCT01133704]; IMPACT [NCT00065442]). Thirty-three AA sip-T pts were matched with 66 CAU sip-T pts based on predicted Halabi survival. Data were evaluated by the Kaplan-Meier method (event rates) and ANOVA (APC activation). Results: Median follow-up was 23.2 mos. AA pts on sip-T had a 20.6-mo longer median OS (45.3 mos; 95% CI 23.4–NE) vs CAU pts (24.7 mos; 95% CI 18.1–29.4) (HR = 0.49; 95% CI 0.26–0.91; p = 0.02). Median event-free survival (time to death or anticancer intervention [ACI]) was 10.7 mos for AA pts (95% CI 8.5–21.5) vs 8.7 mos for CAU pts (95% CI 6.6–11.5) (HR = 0.74; 95% CI 0.47–1.18; p = 0.20). Median time to next ACI was 23.5 mos in AA pts (95% CI 9.4–NE) vs 16.3 mos in CAU pts (95% CI 9.7–25.6) (HR = 0.78; 95% CI 0.42–1.43; p = 0.42). In AA pts, median APC activation was higher with sip-T infusion 1 vs CAU pts (7.0 vs 5.5, p = 0.004). Median cumulative APC activation over the three infusions was 27.7 (22.6–42.4, AA) vs 25.7 (21.5–33.9, CAU) (p = 0.083). Conclusions: Prior studies found sip-T provides OS benefit to both AA and CAU mCRPC pts. Herein, for men treated with sip-T, AA had longer survival, suggesting sip-T may provide greater OS benefit in AA. The basis for this may be biologic (greater APC activation). Further studies with larger sample sizes are needed to confirm if AA pts derive greater OS benefit from sip-T. Clinical trial information: NCT00005947; NCT01133704; NCT00065442.

Long-term follow-up from STAMP, a phase II trial, evaluating sipuleucel-T and concurrent (CON) vs sequential (SEQ) abiraterone acetate + prednisone in metastatic castration-resistant prostate cancer patients (pts).

190 Background: The optimal sequence and combination of life-extending anticancer therapies in mCRPC pts remains unknown. Sipuleucel-T (sip-T), an autologous cellular immunotherapy approved for the therapy of asymptomatic or minimally symptomatic metastatic castration-resistant prostate cancer (mCRPC) pts, was evaluated in combination with abiraterone acetate and prednisone (abi) in the phase II STAMP trial (NCT01487863), with pts randomly assigned to receive CON sip-T + abi or SEQ sip-T followed by abi. The combination was well-tolerated and did not alter the immune response parameters that correlate with overall survival (OS) (Small Clin Can Res 2015). Here, we present long-term follow-up of clinical outcomes, including OS. Methods: mCRPC pts were randomized 1:1 to CON or SEQ therapy with sip-T and abi. Abi began 1 day after (CON) or at wk 10 (SEQ) after the first sip-T infusion and continued for 26 wk of therapy, after which continued abi therapy was permitted. Long-term clinical outcomes included OS, disease-specific death (DSS), progressive disease (PD), time to first anticancer intervention (tACI), and safety. Results: 69 pts were enrolled (35 CON; 34 SEQ). Median OS was 34.0 mo (95% CI, 24.4-not estimable [NE]; 30.0 mo CON; 34.2 mo SEQ; p = 0.921), and median time to DSS was not reached (CON vs SEQ; p = 0.733). Median time to PD was 17.3 mo (95% CI, 9.7–NE; 17.7 mo CON vs 13.9 mo SEQ; p = 0.914; consistent with higher rates of abi discontinuation due to PD in SEQ [26.5% vs 14.3% in CON]). tACI was similar between arms at 15.4 mo (95% CI, 11.0–19.9). No new safety signals were observed with the combination, and no discernable difference in clinical outcomes was observed with CON or SEQ treatments. Conclusions: Long-term follow-up data confirm that sip-T + CON or SEQ abi is well-tolerated, with no new safety signals. No clear differences were observed in clinical outcomes between arms, although the study was not powered to detect these differences. Future and more appropriately powered studies on the effect of sip-T + continuous abi for responding pts may provide further insights on the benefit of combination therapy. Clinical trial information: NCT01487863.

Relationship between smoking, prognostic factors, and outcomes in patient (pts) with metastatic castration-resistant prostate cancer (mCRPC) receiving sipuleucel-T (sip-T): Preliminary analysis of the PROCEED registry.

216 Background: Smoking is associated with poor treatment outcomes after definitive therapy for PC (Steinberger 2015 BJU Int; Joshu 2011 JNCI). However, there is a paucity of data on the effects of active smoking on pts with mCRPC. The PROCEED registry provides an opportunity to evaluate differences in disease characteristics and outcomes by smoking status in men receiving sip-T, an FDA-approved, autologous cellular immunotherapy for asymptomatic or minimally symptomatic mCRPC. Methods: Enrolled pts with mCRPC who never smoked (NS) or were current smokers (CS) were evaluated.Pt characteristics, time to first anticancer intervention (tACI; measured from last sip-T infusion to first ACI; agents: abiraterone, enzalutamide, docetaxel, cabazitaxel, radium-223), PC-specific survival, and OS were assessed. Results: Of 1956 enrolled pts with known smoking status, 904 were NS, 179 were CS; 873 were former smokers and not included in this analysis. Compared with NS, CS were younger, had lower BMI (p < 0.001), higher hemoglobin (Hgb; p < 0.001), lower lactate dehydrogenase (LDH; p = 0.05), and shorter time between PC diagnosis and first sip-T infusion (p = 0.01). Fewer CS pts had Gleason score < 8 (p = 0.2) and prior radical prostatectomy (p = 0.07). CS and NS did not differ in pattern or extent of metastatic disease spread. CS was associated with shorter OS, PC-specific survival, and tACI (Table). Conclusions: CS were younger at enrollment and had shorter OS, PC-specific survival, and tACI. Higher Hgb in CS likely reflects reduced plasma volume and/or increased red cell production. A multivariate analysis of prognostic factors for survival outcomes including smoking status in mCRPC is planned. However, active smoking represents a possible modifiable risk factor in the mCRPC setting. Clinical trial information: NCT01306890. [Table: see text]

Boosting long-term immune responses to sipuleucel-T (sip-T) by retreatment of patients (pts) with metastatic castration-resistant prostate cancer (mCRPC).

196 Background: Sip-T, an autologous cellular immunotherapy for asymptomatic/minimally symptomatic mCRPC, induces immune responses to target antigens prostatic acid phosphatase (PAP) and PA2024, a recombinant protein of PAP and granulocyte macrophage colony-stimulating factor. Immune responses with sip-T correlate with overall survival. PROTECT (phase 3 NCT00779402) assessed sip-T in biochemically recurrent androgen-dependent PC. PROTECT pts developing mCRPC were eligible for P10-1 (phase 2 NCT01338012). Methods: PROTECT pts (sip-T arm) were retreated with sip-T in mCRPC. Antigen presenting cell (APC) activation (CD54 molecule ratio after and before culture with PA2024), cellular (PA2024/PAP ELISPOT; T cell proliferation) and humoral responses were assessed and compared with treatment-naïve mCRPC pts (IMPACT NCT00065442; STAMP NCT01487863; STRIDE NCT01981122). Results: Caucasian men (n=8), median follow-up 9.2 y and age 74 y, had an ECOG PS of 0 (75%) or 1. Median APC activation with sip-T infusion 1 was ~3-fold higher in P10-1 (20; n=7) vs treatment-naïve mCRPC pts (7; n=447). In P10-1, high magnitude cellular and humoral responses were seen at baseline (BL) (Table). Immune memory was heterogeneous, strong BL humoral and/or robust cellular memory was observed. Sip-T boosted PA2024/PAP cellular and humoral responses (Table). Immune responses were maintained up to wk 52, and were higher over time vs 1st time treated mCRPC pts. Conclusions: Sip-T in an earlier disease setting generated sustained antigen-specific immune memory lasting up to 10 y. Consistent with vaccine-induced immune responses, sip-T retreatment rapidly boosted both cellular and humoral antigen-specific responses in mCRPC pts. Clinical trial information: NCT01338012. [Table: see text]

Genetic Engineering of Pluripotent Cells for the Continuous Derivation of Off-the-Shelf Effector Lymphocytes with Enhanced Therapeutic Persistence By Overcoming the Host Histocompatibility Barrier

Encouraging clinical outcomes in autologous cellular immunotherapy have garnered hope and excitement. However, considerable challenges and limitations of patient-derived cancer immunotherapies remain and need to be addressed in order to consistently deliver reliable and efficacious therapies with broadened applicability. Human induced pluripotent stem cells (hiPSCs) are a unique, renewable source for the continuous generation of cellular therapeutics for the treatment of hematological and non-hematological malignancies, and represent a highly promising approach for overcoming many of the limitations of autologous therapy. To advance the promise of hiPSC technology as an "off-the-shelf" source of cellular therapeutics, several considerations need to be addressed. Enabling cell transfer across histocompatibility barriers to permit persistence and therapeutic efficacy in an allogeneic setting is a key requirement. In addition to improving persistence, the ability to overcome histocompatibility barriers may facilitate multi-dosing regimens which may be a requirement in more advanced and complicated disease settings.Genetic incompatibilities between donor and recipient among the classical human leukocyte antigen (HLA) molecules is the leading cause of alloresponse by the host immune system and is currently mitigated by immunosuppressive strategies. Unfortunately, this treatment strategy is not only a stressful event for the patient but also damages the endogenous immune system, compromising the patient’s ability to continue to fight the disease and opportunistic infections. Genetic editing of the HLA genes to generate histocompatible universal cell products is a viable opportunity that is currently being investigated. In addition to selective editing of unique genes to avoid a T cell mediated alloresponse, additional considerations such as natural killer (NK) cell-mediated rejection will need to be addressed. We have previously demonstrated that our proprietary reprogramming platform supports efficient and rapid derivation of clonal hiPSC lines with properties indicative of the naïve state of pluripotency. In addition to maintaining a homogeneous renewable population of hiPSCs, our platform is amenable to precise multi-gene and multi-loci targeted engineering at the single cell level, in both nuclease -dependent and -independent strategies. Furthermore, we have shown through small molecule-guided differentiation protocols, these highly-stable pluripotent cell lines can be banked and repeatedly tapped to consistently produce homogenous populations of immune cells with enhanced effector properties.Here we demonstrate a multi-faceted and comprehensive approach for the generation of immune tolerant hiPSCs and hiPSC-derived immune effector cells. We successfully combined deletion of classical HLA molecules with enforced expression of robust immunosuppressive proteins, including non-classical HLA molecules, to generate clonal hiPSC lines with the ability to escape immune rejection for "off-the-shelf" (OTS-hiPSCs) cellular immunotherapy. Utilizing in vitro real-time quantitative live cell analysis we determined that OTS-hiPSCs elicit a significantly decreased cytotoxic response from both activated peripheral blood (PB)-NK cells and primed PB-T cells compared to wildtype controls. Furthermore we demonstrate that OTS-hiPSCs exhibit improved persistence in xenograft studies in vivo. Bilateral teratomas were formed in a non-conditioned, fully immune-competent recipient mice using luciferized wildtype and OTS-hiPSCs. Daily bioluminescence imaging over a period of 7 days revealed a significant increase (>50 fold difference) in persistence of OTS-hiPSCs compared to wildtype hiPSCs during the 60-144 hour post injection window. Lastly we demonstrate that OTS-hiPSCs can successfully differentiate into functional effector lymphocytes using our potent chemically-defined monolayer hematopoietic differentiation platform. Our current studies focus on the functional characterization of OTS-hiPSC-derived effector lymphocytes in humanized mouse models and generating increased potency of OTS-hiPSC-derived effector lymphocytes through precise genetic engineering of antigen targeting and costimulatory proteins to create and optimized source of "off-the-shelf" cell-based immunotherapies. DisclosuresBauer:Fate Therapeutics: Employment. Clarke:Fate Therapeutics: Employment. Sasaki:Fate Therapeutics: Employment. Groff:Fate Therapeutics: Employment. Lee:Fate Therapeutics: Employment. Lan:Fate Therapeutics: Employment. Abujarour:Fate Therapeutics: Employment. Bonello:Fate Therapeutics: Employment. Burrascano:Fate Therapeutics: Employment. Robinson:Fate Therapeutics: Employment. Bjordahl:Fate Therapeutics, Inc: Employment. Gaidarova:Fate Therapeutics: Employment. Abbot:Fate Therapeutics: Employment. Wolchko:Fate Therapeutics: Employment. Shoemaker:Fate Therapeutics: Employment, Equity Ownership. Valamehr:Fate Therapeutics, Inc: Employment.

Phase 2 trial results of DN24-02, a HER2-targeted autologous cellular immunotherapy in HER2+ urothelial cancer patients (pts).

4513Background: DN24-02 is an autologous cellular immunotherapy consisting of antigen-presenting cells (APC) cultured with BA7072, a recombinant HER2-derived antigen (HER500) linked to granulocyte ...

Analysis of the PROCEED registry by baseline prostate-specific antigen (PSA) quartiles: Preliminary analysis of real-world sipuleucel-T (sip-T) use.

193 Background: Sip-T is an FDA-approved, autologous cellular immunotherapy for asymptomatic or minimally symptomatic metastatic castration-resistant prostate cancer (mCRPC). Post-hoc analysis of the phase 3 IMPACT study revealed that compared with the highest baseline PSA quartile, patients (pts) in the lowest quartile treated with sip-T had a larger overall survival (OS) benefit, suggesting sip-T is most beneficial if administered earlier in the treatment of mCRPC (Schellhammer et al., Urology. 2013.). This analysis evaluated pt characteristics by PSA quartiles in PROCEED (NCT01306890). Methods: Pts enrolled in PROCEED with baseline PSA and ≥ 1 sip-T infusion were included in this analysis. PSA values were divided into quartiles, and trends in baseline pt characteristics were evaluated as well as time to first anticancer intervention (tACI) with approved mCRPC therapies (docetaxel [D], cabazitaxel, abiraterone [abi], or enzalutamide [enz]) following sip-T treatment. Radium-223 was approved too late in the conduct of PROCEED to be included in the tACI analysis. Results: PSA quartiles from 1880 eligible PROCEED pts were lower than those of IMPACT (Table). Pts in the highest PROCEED quartile were older, more likely to have ECOG performance status ≥ 1, > 10 bone metastases, visceral metastases, and higher ALP and LDH, and lower hemoglobin compared with the lowest PROCEED quartile. More African American men and greater prior systemic therapy use were observed in the highest PSA quartile. Following sip-T, the median tACI (11.0, 8.2, 7.6, and 6.6 mos) was inversely proportional to PSA quartile. Conclusions: Lower baseline PSA values in PROCEED relative to IMPACT suggest that in a real-world setting, clinicians are using sip-T earlier in the treatment of mCRPC. Pts in the lowest PSA quartile had the best prognostic features and longest tACI. Additional patient follow-up is ongoing to evaluate OS and survival by quartile from PROCEED. Clinical trial information: NCT01306890. [Table: see text]

Time to next line therapy after initiation of sipuleucel-T in metastatic castration-resistant prostate cancer patients.

341 Background: Sipuleucel-T is an autologous cellular immunotherapy approved for patients with symptomatic or minimally asymptomatic metastatic castration-resistant prostate cancer based on prolongation of overall survival. We sought to retrospectively analyze the type and time to next-line therapy after the initiation of Sipuleucel-T (Sip-T) in the era of multiple new other therapeutic compounds that became available since approval of Sip-T to better understand the context of utilization of this immunotherapy in the current era. Methods: We performed a retrospective analysis of 53 patients with metastatic prostate cancer (PC) who have been treated with Sip-T at The City of Hope Medical Center between September 2010 and April 2013 and subsequently received another therapy. Variables included age at Sip-T treatment, Karnofsky Performance Score (KPS), Gleason score at diagnosis, extent of metastatic disease (limited or extensive), and white blood cell (WBC) count pre and post (Sip-T). PSA was measured at six time points (3 pre and 3 post Sip-T) and these were analyzed using a mixed linear regression model. A Cox Proportional Hazard model was used to examine predictors of time in days to next therapy as a function of the above variables including mixed model slopes of PSA. Results: Kaplan – Meier estimated median time to next treatment among the 53 patients was 122 days (95% CI, 86-177 days) and was significantly predicted by slope of PSA from the mixed model (HR = 25.883, p < .0001), WBC post therapy (HR = 1.352, p = 0.0017), and age at Sip-T (HR = 1.044 p = 0.0492). KPS, Gleason score, pre Sip-T WBC, and the extent of metastatic disease were not predictive. Most patients had abiraterone acetate for next treatment (n = 32, 58.2%). Other treatments included docetaxel (n = 5, 9.1%), orteronel with prednisone or prednisone alone (n = 12, 21.8%), and others (n = 6, 10.9%). Conclusions: In our experience median time to subsequent therapies was shorter than reported in pivotal Phase III study. Shorter time to post-Sip-T therapy was associated with older age, higher levels of WBC post-Sip-T therapy and more rapid rate of increase in the PSA level.

Changing characteristics of patients treated with sipuleucel-T (sip-T) over time: Real-world experience from the PROCEED registry.

320 Background: Sip-T is an autologous cellular immunotherapy approved by the FDA for the treatment of asymptomatic or minimally symptomatic metastatic castration-resistant prostate cancer. PROCEED (NCT01306890) is a phase 4 registry evaluating men receiving sip-T therapy in the US. Patient characteristics and treatment trends were assessed from 2011 to 2013, when several agents with an overall survival benefit became commercially available. Methods: For patients enrolled from 2011 to 2013, baseline patient and disease characteristics at the first sip-T infusion, trends in prior therapy, and pre–sip-T baseline prostate-specific antigen (PSA) levels were examined year over year. Results: From 2011 to 2013, 1902 patients were enrolled and received ≥ 1 sip-T infusion: 2011, n = 145; 2012, n = 967; 2013, n = 790. During this time period, enrollment of African American men nearly doubled from 6.9% to 13.4%, and central venous catheter use to facilitate sip-T infusion decreased (from 53.8% to 44.1%). Median baseline lactate dehydrogenase (LDH) levels and the number of lymph node metastases also decreased as well as median baseline PSA values (17.8 ng/mL to 11.9 ng/mL [P = 0.002]). Prior use of first-generation anti-androgens (from 73.1% to 60.5%), ketoconazole (17.2% vs. 6.3%), and estrogen (4.8% vs. 1.6%) decreased along with prior docetaxel use (19.3% vs. 7.5%). In contrast, prior investigational use of abiraterone acetate (from 3.4% to 8.9%) and enzalutamide (1.4% vs. 3.2%) increased over time. Conclusions: Over the duration of PROCEED, the decrease in baseline PSA, lower LDH, fewer nodal metastases, and decline in prior docetaxel use suggest that sip-T is being used earlier in the course of metastatic castration-resistant disease. Moreover, second-line hormonal therapy use with agents that do not improve overall survival appears to be substituted by therapies that do. This decrease in second-line hormonal therapies during PROCEED could suggest a real-world preference for earlier sip-T use. Clinical trial information: NCT01306890.

Development of ‘enhanced’ potency immunotherapy products using nonviral approaches

In the next 5–10 years we could see cellular-based pharmaceuticals, or cell therapy, meeting the unmet medical needs of thousands of people. How this therapy will meet these needs depends on the ability of researchers and manufacturers to successfully and cost effectively manufacture and deliver engineered cell-based therapeutic products that are safe and exhibit enhanced potency with resulting durable, meaningful clinical efficacy. The ability to engineer such enhanced potency using nonviral, cGMP-compliant, automated and closed system manufacturing processes will represent a significant advantage. To outline how such a process might work, we have summarized the application of a scalable, cGMP-compliant, electroporation platform for engineering dendritic cells (DCs), NK cells and T cells for development of cellular immunotherapies targeting hematological malignancies and solid tumors. Autologous cellular immunotherapy refers to a class of therapies that are designed to stimulate a specific immune respons...

Cellular immunotherapy of chronic inflammation and autoimmunity using autologous antigen-specific T regulatory (Treg) cells

Among the most innovative immunotherapies, autologous cellular immunotherapy aims at treating patients with their own immune cells that, before reinjection, have been educated ex vivo to fight disease. Antigen-specific regulatory T cells (Ag-Treg) are recognized as a promising tool for therapeutic intervention in patients with chronic inflammation and autoimmunity. Ovasave ® is an autologous ovalbumin-specific Treg (Ova-Treg) product that is in development for the treatment of severe Crohn's disease patients refractory to available treatments. Ovasave ® has shown a good tolerability and dose-related efficacy in a first-in-man open-labeled phase I/IIa study in refractory Crohn's disease patients. In this study, a 75% response rate and a 38% remission rate on the CDAI (Crohn's Disease Activity Index) were observed at the best dose. In addition, clinical response was correlated with a decrease in vitro proliferation of patient's white blood cells in response to ovalbumin, indicating that decreased proliferation to Ag-Treg specific antigen could be used as a biomarker of clinical response. A randomized controlled phase IIb clinical study with Ovasave will start mid-2014 to confirm the efficacy and tolerability of Ovasave ® in refractory's Crohn's disease patients. Ag-Treg manufacturing has been developed to be highly cost-effective and logistically simple: multiple years of treatment doses are manufactured by one processing from one blood sample. Ovasave ® is the lead product from TxCell's ASTrIA platform Ag-Treg products. From this platform, Col-Treg, an autologous collagen-II specific based product is in the final preclinical stage of development for the treatment of patients with autoimmune uveitis, an orphan chronic inflammatory condition of the eye, with a phase I/IIa clinical study planned for 2015. With Ovasave ® and Col-Treg as novel, personalized cellular immunotherapies for chronic autoimmune inflammatory diseases, Ag-Tregs represent a new therapeutic opportunity for patients who today have few or no treatment options.

Optimizing the efficiency and quality of sipuleucel-T delivery in an academic institution.

Sipuleucel-T, an autologous cellular immunotherapy, is approved for the treatment of certain patients with metastatic castration-resistant prostate cancer (mCRPC). Sipuleucel-T is the first personalized treatment for prostate cancer to be manufactured using the immune system of each individual patient. Patient preparation and compliance are critical because patients undergo serial leukapheresis and reinfusion procedures within a relatively short time period, which may result in transient reactions. The study aims to identify patients best suited for sipuleucel-T treatment, provide an overview of treatment, and encourage infusion sites to consider a primary contact model for the efficient coordination of care. Treatment experiences were evaluated from 124 patients with mCRPC who received sipuleucel-T from January 2010 to August 2013 according to current best practices. Feedback was collected from reflective interdisciplinary discussion within the sipuleucel-T delivery team (nurses, advanced practice providers, urologists, and medical oncologists). Early patient identification and education on treatment rationale, delivery, and expectations help ensure a successful sipuleucel-T treatment experience. A multidisciplinary coordinated-care process can facilitate proficient sipuleucel-T delivery, and the selection of a primary contact for care coordination offers benefits, such as clear and efficient education.

Targeted treatment of metastatic castration-resistant prostate cancer with sipuleucel-T immunotherapy.

ContextProstate cancer remains highly prevalent and has a poor clinical outcome once metastatic. Sipuleucel-T is an autologous cellular immunotherapy approved for the treatment of metastatic castration-resistant prostate cancer (mCRPC). Sipuleucel-T treatment extends survival but is independent of traditional short-term markers of treatment response observed with chemotherapy and contemporary hormonal treatments. Therefore, it is essential that clinicians understand the mechanism of action of sipuleucel-T and how this can translate in the clinic. ObjectiveThis article aims to summarize the current knowledge of sipuleucel-T therapy and its effects in mCRPC.Evidence acquisitionRelevant publications describing sipuleucel-T clinical data and information relating to immunotherapies were identified.Evidence synthesisTreatment with sipuleucel-T extends survival, with side effects being usually mild or moderate and manageable within the outpatient setting. The long-term immune responses generated by sipuleucel-T correlate with a survival benefit. Sipuleucel-T shows a greater magnitude of clinical benefit when used in patients earlier in the mCRPC setting.ConclusionsSipuleucel-T stimulates long-lived immune responses that translate into long-term clinical benefit. The treatment course (three infusions at weeks 0, 2, and 4) is associated with manageable side effects. Short-term markers of future benefit would be clinically useful, and information on effective treatment combinations or sequences is awaited.Patient summarySipuleucel-T treatment directs the patient’s own immune system to target and remove prostate cancer cells and increases life expectancy. Patients whose cancer is less advanced generally have a more ‘active’ immune system and may benefit the most from this treatment.

Adjuvant cellular immunotherapy in patients with resected primary non-small cell lung cancer

Postoperative non-small cell lung cancer (NSCLC) patients require adjuvant therapy to improve their prognosis. In this study, we investigated the efficacy of a sequential combination of autologous cellular immunotherapy (CIT) and chemotherapy for postoperative NSCLC. This retrospective study included 120 postoperative NSCLC patients: 60 cases received only chemotherapy; 33 cases received chemotherapy and sequential CIT with cytokine-induced killer (CIK) cells; and 27 cases received chemotherapy and sequential CIT with alternate CIK and natural killer (NK) cells. Survival analysis showed significantly higher overall survival rates in the CIT group compared with the control group. Overall survival was higher in patients who received CIT with alternate CIK and NK cells than those who received treatment with only CIK cells. Multivariate analysis showed that adjuvant CIT was an independent prognostic factor for overall survival of patients with NSCLC. In subgroup analyses, adjuvant CIT significantly improved the overall survival of patients with less than 60 y old and positive lymph node. In conclusions, these data indicate that adjuvant CIT, especially with alternate application of CIK and NK cells, is an effective therapeutic approach to prolong survival of patients with NSCLC, particularly for patients ≤60 y old with positive lymph nodes.

Randomized phase-2 study of sipuleucel-T with or without radium-223 in men with asymptomatic/minimally symptomatic bone-metastatic castrate-resistant prostate cancer (CRPC).

TPS5076 Background: Sipuleucel-T is an autologous cellular immunotherapy indicated for men with asymptomatic/minimally symptomatic metastatic CRPC. Recent analysis of immune responses in men treate...

Administration of sipuleucel-T (sip-T) infusions (infs) outside of the clinical trial setting: Data from the PROCEED registry.

e16027 Background: Sip-T is an autologous cellular immunotherapy approved for patients (pts) with metastatic castration-resistant prostate cancer, and no or minimal symptoms. Pts undergo leukaphere...

Changes in circulating and intratumoral T cell clonotypes in sipuleucel-T-treated prostate cancer patients.

e16008 Background: Sipuleucel-T (sip-T) is an autologous cellular immunotherapy approved by the FDA and EMA for treatment of certain patients with asymptomatic or minimally symptomatic metastatic c...

Characteristics of African Americans (AAs) treated with sipuleucel-T (sip-T): Comparison of clinical trial and real-world experience.

272 Background: AA men are underrepresented in randomized clinical trials (RCTs) for prostate cancer, despite an almost 2-fold greater incidence in AA vs Caucasian populations. Sip-T is an autologous cellular immunotherapy approved by the FDA and EMA for the treatment of certain patients (pts) with asymptomatic or minimally symptomatic metastatic castration-resistant prostate cancer. AA enrollment in three sip-T phase 3 RCTs was 5.8% (n=43). While no definitive conclusions were drawn, median overall survival (OS) suggested AAs benefit from sip-T. PROCEED, an ongoing phase 4 registry, expanded efforts to increase AA enrollment to better characterize this population and the safety, product parameters (PP), and OS of AAs treated with sip-T. Methods: PROCEED enrolled 1973 pts treated with commercial sip-T within 6 months of registration. Efforts, such as selecting racially diverse sites and highlighting AA enrollment in PROCEED communications and investigator meetings, were used to boost AA enrollment. Baseline Gleason score, Eastern Cooperative Oncology Group performance status (ECOG), prostate-specific antigen (PSA), and alkaline phosphatase (ALP) were compared between RCTs and PROCEED. Safety and survival analyses are ongoing. Results: PROCEED AA enrollment was 11.7% vs 7.1% US RCT nonwhite enrollment rate and approaches the US AA population of 13.7%. Baseline AA pt characteristics were: lower median PSA and ALP levels in PROCEED vs RCTs, higher ECOG >0 in PROCEED vs RCTs, and higher Gleason score ≥8 in PROCEED vs RCTs (Table). Conclusions: Efforts to boost AA enrollment in PROCEED to a proportion comparable to the US AA population succeeded. The lower baseline PSA of AAs in PROCEED is similar to the PSA observed in the entire PROCEED population. Safety, PP, and OS will be reported with longer follow-up. Clinical trial information: NCT01306890. [Table: see text]

Antigen-specific immune responses through 24 months in the STAND trial: A randomized phase 2 study evaluating optimal sequencing of sipuleucel-T (sip-T) and androgen deprivation therapy (ADT) in biochemically-recurrent prostate cancer (BRPC).

171 Background: Sip-T is an autologous cellular immunotherapy targeting prostatic acid phosphatase (PAP), approved for treatment of asymptomatic/minimally symptomatic metastatic castration-resistant prostate cancer. STAND evaluates sequencing of sip-T and ADT in men with BRPC at high risk of metastases. Here we report interim assessments of cellular and humoral responses through 24 mos. Methods: Men (n=68)were randomized 1:1 to sip-T followed by ADT (2 wks after 3rd infusion; Arm 1) or ADT (3-mo lead-in) followed by sip-T (Arm 2). Product parameters (total nucleated cell [TNC] count, antigen presenting cell [APC] count, APC activation) were determined with each product manufacture. Cellular and humoral immune responses were analyzed through 24 mos with a repeated measures statistical model. Results: Sample size ranged 8–28 for cellular responses and 34–64 for humoral responses. PA2024 ELISPOT count increased vs baseline at most timepoints (p<0.05) and was lower in Arm 2 vs Arm 1 (p=0.015). PA2024 antigen-specific T-cell proliferation increased from baseline at all timepoints (p≤0.001) and was lower in Arm 2 vs Arm 1 (p<0.001). PA2024 antibody titers were similar between treatment arms (p=0.976). PA2024 antibody titer was significantly higher at the 3rd sip-T infusion visit and remained elevated at 24 mos (23 times higher on average vs baseline; p<0.001). A similar antibody titer profile was reported for PAP but of lesser magnitude. The number of immune responders (post-baseline antibody titer ≥25,600) was similar at any timepoint between arms (Arm 1: 30/34, 88.1%; Arm 2: 32/34, 94.1%; p=0.673). Higher cumulative TNC and baseline hemoglobin positively correlated with maximum PA2024 antibody titer response (p<0.05). Conclusions: Sip-T induced a robust immune response sustained to 24 mos in men with BRPC. Cellular response appeared to differ according to treatment sequence; humoral response was similar between treatment arms. Given its consistent association with the humoral response, cumulative TNC count may be a potential biomarker of response to sip-T. Clinical trial information: NCT01431391.

Immune response from STRIDE, a randomized, Phase II, open-label study of sipuleucel-T (sip-T) with concurrent vs sequential enzalutamide (enz) administration in metastatic castration-resistant prostate cancer (mCRPC)

Meeting abstracts P12-2 (STRIDE; [NCT01981122][1]) is an ongoing, randomized, Phase II, open-label study evaluating concurrent vs sequential administration of the androgen receptor inhibitor, enz, with the autologous cellular immunotherapy, sip-T. The primary aim of this study is to determine if