OncLive.
CAR T-cells Rapidly Evolving as Cancer Therapies
Silas Inman @silasinman
Published Online: Sunday, March 20, 2016
Dr Jae Park
Jae H. Park, MD
Chimeric antigen receptor (CAR)-modified T-cell therapies have demonstrated durable complete responses (CRs), the majority of which are minimal residual disease (MRD)-negative, for patients with relapsed/refractory B-cell acute lymphoblastic leukemia (ALL). However, several questions still remain regarding their optimal use and applicability outside of ALL, according to Jae H. Park, MD, at the 2016 International Congress on Hematologic Malignancies.
“What we have learned from ALL is that they are very effective at getting to complete remissions, and the responses are very deep. Durable responses have been observe in a subset of patients who did not get subsequent allogeneic transplant,” said Park, Leukemia Service at Memorial Sloan Kettering Cancer Center. “There are a lot of questions, as we move forward, such as the role of the tumor microenvironment, and whether this can be applied outside of ALL.”
A CAR therapy consists of the binding domain from an antibody connected to the signaling domain of a T cell. The process for the therapy involves the insertion of a CAR gene subclone that recognizes a tumor antigen into a viral vector, which is transduced and expanded ex vivo in T cells and then administered to the patient. The resulting therapy has the specificity of an antibody with the killing capacity of a T cell, Park said.
At this point, clinical trials have primarily focused on CD19 and other markers on B-cell malignancies. CD19 was explored first, since it is not expressed in hematopoietic stem cells and is overexpressed in B-cell lymphoma, leukemia, and occasionally in multiple myeloma.
“With CD19, because it's not expressed on stems cells, we are only targeting mature cells. However, because the antigen is also expressed in normal B-cells, we do cause B-cell aplasia,” said Park. “We also have CARs planned for CD22 and CD20, which are other common B-cell antigens.”
CAR-modified T-cell therapies have undergone several changes since they were initially introduced, and continue to be improved and modified. They offer the advantage of having HLA-independent antigen recognition, which provides broad application across both solid and blood cancers. These therapies are also active in both CD4+ and CD8+ T cells, with a minimal risk of graft-versus-host disease.
“This is potentially a living drug. They can survive within the body and provide immunity against cancer,” said Park. “Because this is a genetic therapy, the door is open to more genetic modifications and better versions of the T-cells as the years go on. In the future, we may even be able to accomplish better results, and in solid tumors as well.”
Findings in Acute Lymphoblastic Leukemia
Historically, patients with ALL who are in their first relapsed have a 5-year overall survival (OS) of 7% to 8% and a 2-year OS of 11%. Additionally, in clinical trials studying conventional chemotherapy, the CR rates ranged between 18% and 45% for patients with relapsed/refractory ALL. These poor outcomes emphasize the need for novel therapies, said Park.
In phase I trials exploring CAR T-cell therapies, leukapheresis is conducted upfront to collect T cells for modification followed by chemotherapy, to keep the disease in check. After the T-cell production period, which takes 2 to 3 weeks, a bone marrow biopsy is conducted to assess the response to chemotherapy. After this step, the patient will receive a conditioning chemotherapy followed by an infusion of the T-cell therapy.
“The conditioning therapy, what we think it is doing, is lymphodepletion. It simply is creating a space for these T-cells to get in there and expand. In order for this T-cell therapy to be successful, you do need T-cell activation and expansion,” said Park.
As early phase results have been analyzed, a number of modifications were made to this study design. Initially, the conditioning chemotherapy was cyclophosphamide alone; however, fludarabine has now been added, Park noted. Additionally, the second infusion of the CAR T-cell therapy is customized, based on the number of blast cells present, to address toxicity concerns.
“The dosing adjustments here are counterintuitive, in a way, the more disease you have, you actually need less T-cells, since disease really means antigen load,” said Park. “The more antigen there is, the T-cells will engage and expand a lot quicker and faster, and as they do that, that is when the toxicity comes in.”
CAR T-cells in Action
As an example of the outcomes seen with CAR T-cell therapy, Park presented data from a 46-patient phase I study that was conducted by Memorial Sloan Kettering Cancer Center (NCT01044069). In this example, the median age of patients was 45 years and the median number of prior therapies was 3.1
In evaluable patients with CD19-positive B-cell ALL treated with the CAR T-cell therapy (n = 45), the overall CR rate was 82.2%. In those with morphologic disease (≥5% blasts; n = 24), the CR rate was 75% and for those with minimal disease (<5% blasts; n = 21) the CR rate was 90.5%. Of patients who achieved a CR, 83% were negative for MRD. The median time to a CR was 21 days.
In a subgroup analysis, the response rate was higher in patients with Philadelphia chromosome (Ph)-positive ALL (n = 14), with a CR rate of 92.9%. In the Ph-negative group (n = 31), the CR rate was 77.4%. Additionally, CR rates were superior in younger patients compared with adults. In those aged 18 to 30 (n = 11), the CR rate was 90.9%. In those aged 30 to 59 years (n = 10), the CR rate was 80%.
Across the full study population, the median OS was 9 months, with a 6-month OS rate of 65%. In those who achieved a CR, the median OS was 10.6 months, with a 6-month OS rate of 71%. The median OS was 10.6 months in those who did not receive a subsequent stem cell transplant and was not yet reached in those who did receive a transplant. The 6-month OS rates were similar between the two groups, at 80% and 79%, respectively.
“Standard of care says they should go on to transplant. If the patient hasn't had a transplant, we do still recommend a transplant,” said Park. “These numbers are very small, so I am not suggesting that a patient shouldn't get transplant, it still seems to be uncertain in this situation.”
This experience is not unique, in regard to efficacy, Park noted. A number of clinical trials have been conducted looking at various CAR T-cell therapies for patients with relapse/refractory ALL. Across the studies looking at these agents in adult patients, the CR rate has ranged from 83% to 89%. Additionally, in studies with OS findings, the results appear consistent between trials.
In the pediatric setting, a number of promising results have also been demonstrated. In one example exploring CTL019,2 the 6-month event-free survival (EFS) was 63%, the 6-month OS was 78%, and the CR rate was 90%. In a second study exploring KTE-C19,3 the 6-month OS and EFS rates were approximately 65% and 80%, respectively. The CR rate was 70%.
“The response rates are quite excellent across all of these studies. The follow-up is relatively short for these studies; they are all fairly new. That is something to keep in mind for these results,” Park said.
Over a dozen clinical trials are currently enrolling patients with B-cell ALL looking at CD19-targeted CAR T-cell therapies, including 4 phase II investigations. The University of Pennsylvania (NCT02030847), researchers in Sweden (NCT02132624), Juno Therapeutics (NCT02535364), and Seattle Children’s Hospital (NCT02028455) are conducting these trials.
“Encouragingly there are some phase II trials going,” said Park. “All of these trials employ a similar design but there are some differences in the trials and therapies, such as the binding domain, the mode of transduction, cell source, patient population, and method of lymphodepletion.”
CAR T-cell Associated Adverse Events
The major adverse events (AEs) associated with CAR T-cell therapies are cytokine release syndrome (CRS) and neurologic changes. These occur across all of the CAR T-cell therapies, since they each have similar mechanisms of action.
“This is an infusion of T-cells, and if you have this type of event, there is really no turning the drug off or holding the drug. Once they are in, they are in,” said Park. “This is the reason we need to modify the studies to mitigate the side effects.”
A correlation exists between CRS and disease burden, which is the rationale that led to dose reductions in those with a higher disease burden. This event can be monitored using C-reactive protein levels, once detected interleuken-6 therapy can effectively treat CRS. “The IL-6 receptor inhibitor tocilizumab is highly effective at reversing the symptoms of cytokine release syndrome,” said Park.
The incidence of these toxicities has varied between clinical trials, with severe CRS occurring in as many as 92% of patients enrolled in one early study. Additionally, this event led to deaths in early studies. However, with proper management techniques now in place, severe CRS has become less common.
In addition to CRS, grade 3/4 neurotoxicity has been seen in approximately 28% of patients in some studies. At this time, the mechanism behind this event is not yet fully understood. Neurotoxicity generally consists of an altered mental state, aphasia, and seizures or seizure-like activity. “These do get better over time, and are not really prolonged in duration,” said Park.
Ongoing Studies Outside of ALL
There are a number of studies exploring CAR-modified T-cells for patients with acute myeloid leukemia (AML). These studies are all phase I, and are being conducted across several sites, including the USA, China, and Australia. These therapies have a variety of CAR targets, including CD33, CD123, CD28, and NKG2D.
At this time, a single target that appears most effective has not yet been identified for patients with AML. Additionally, the off-target toxicity of these therapies remains unclear, specifically whether they could lead to prolonged or permanent myelosuppression. At this point, there is little data supporting the impact of these agents in high volume disease and the durability of response.
A number of preclinical trials are currently in progress to assess strategies to overcome the current limitations of CAR T-cell therapies for AML or solid tumors. These include the exploration of potential "on" and "off" switches to control T-cell activation. Moreover, split receptor/dual antigen-targeting T-cells are in development along with so-called "armored" CARs.
“The armored CAR T-cells involves building in additional cytokines with T-cells to be even more potent, and to take advantage of the innate immune system,” Park said.
With the number of studies currently ongoing, and the level of competition, the field continues to evolve rapidly. Outside of acute leukemia, CAR T-cell therapies are also being explored in non-Hodgkin lymphoma, multiple myeloma, and across a variety of cancers.
- See more at: http://global.onclive.com/conference-coverage/hematology-2016/car-t-cells-rapidly-evolving-as-cancer-therapies#sthash.Jv7BofbG.dpuf
lunes, 28 de marzo de 2016
Driving CAR T-cells forward
Nature Reviews Clinical Oncology | Review
Driving CAR T-cells forward
Hollie J. Jackson, Sarwish Rafiq & Renier J. Brentjens
Nature Reviews Clinical Oncology
(2016)
doi:10.1038/nrclinonc.2016.36
Published online
22 March 2016
Abstract
The engineered expression of chimeric antigen receptors (CARs) on the surface of T cells enables the redirection of T-cell specificity. Early clinical trials using CAR T cells for the treatment of patients with cancer showed modest results, but the impressive outcomes of several trials of CD19-targeted CAR T cells in the treatment of patients with B-cell malignancies have generated an increased enthusiasm for this approach. Important lessons have been derived from clinical trials of CD19-specific CAR T cells, and ongoing clinical trials are testing CAR designs directed at novel targets involved in haematological and solid malignancies. In this Review, we discuss these trials and present strategies that can increase the antitumour efficacy and safety of CAR T-cell therapy. Given the fast-moving nature of this field, we only discuss studies with direct translational application currently or soon-to-be tested in the clinical setting.
Introduction
Chimeric antigen receptors (CARs) consist of an extracellular antigen-recognition domain, which is usually an antibody single-chain variable fragment (scFv), but can also be a peptide or another protein, linked to an intracellular signalling domain — usually the CD3ζ (CD3 zeta) chain of the T-cell receptor. The extracellular portion of the CAR permits the recognition of a specific antigen by a T cell and, subsequently, the signalling domains stimulate T-cell proliferation, cytolysis and cytokine secretion to eliminate the target cell. The patients' own T cells (or those from an allogeneic donor) are isolated, activated and genetically modified to generate CAR T cells, which are then infused into the same patient. This approach carries a very low risk of graft-versus-host disease and enables lipid, protein and carbohydrate antigens to be targeted by T cells in an MHC-unrestricted fashion. Additionally, one CAR design can be used to treat all cancers expressing the same antigen. The need to generate T cells for each patient was once considered to be a financial and technical obstruction to this therapeutic approach, but the success of CAR-T-cell therapy for the treatment of B-cell acute lymphoblastic leukaemia (B-ALL) has demonstrated that CAR T cells can be produced efficiently and for a reasonable cost.
CD19-targeted CAR T cells have been investigated clinically for the treatment of B-cell malignancies. CD19-targeted CAR-T-cell therapy has repeatedly demonstrated to produce marked antitumour responses in patients with B-ALL1, 2, 3. Following this success, much attention has been devoted to the development of CAR T cells for the successful treatment of other haematological malignancies and solid tumours. In this Review, we discuss successful CD19-targeted CAR-T-cell therapies, CAR-T-cell designs targeting other molecules for the treatment of haematological malignancies, and novel targets proposed for the treatment of solid tumours. This discussion will be limited to approaches with registered clinical trials. In our opinion, the findings from these trials will be instrumental to increase our understanding and optimize the efficacy of this promising cancer treatment.
Driving CAR T-cells forward
Hollie J. Jackson, Sarwish Rafiq & Renier J. Brentjens
Nature Reviews Clinical Oncology
(2016)
doi:10.1038/nrclinonc.2016.36
Published online
22 March 2016
Abstract
The engineered expression of chimeric antigen receptors (CARs) on the surface of T cells enables the redirection of T-cell specificity. Early clinical trials using CAR T cells for the treatment of patients with cancer showed modest results, but the impressive outcomes of several trials of CD19-targeted CAR T cells in the treatment of patients with B-cell malignancies have generated an increased enthusiasm for this approach. Important lessons have been derived from clinical trials of CD19-specific CAR T cells, and ongoing clinical trials are testing CAR designs directed at novel targets involved in haematological and solid malignancies. In this Review, we discuss these trials and present strategies that can increase the antitumour efficacy and safety of CAR T-cell therapy. Given the fast-moving nature of this field, we only discuss studies with direct translational application currently or soon-to-be tested in the clinical setting.
Introduction
Chimeric antigen receptors (CARs) consist of an extracellular antigen-recognition domain, which is usually an antibody single-chain variable fragment (scFv), but can also be a peptide or another protein, linked to an intracellular signalling domain — usually the CD3ζ (CD3 zeta) chain of the T-cell receptor. The extracellular portion of the CAR permits the recognition of a specific antigen by a T cell and, subsequently, the signalling domains stimulate T-cell proliferation, cytolysis and cytokine secretion to eliminate the target cell. The patients' own T cells (or those from an allogeneic donor) are isolated, activated and genetically modified to generate CAR T cells, which are then infused into the same patient. This approach carries a very low risk of graft-versus-host disease and enables lipid, protein and carbohydrate antigens to be targeted by T cells in an MHC-unrestricted fashion. Additionally, one CAR design can be used to treat all cancers expressing the same antigen. The need to generate T cells for each patient was once considered to be a financial and technical obstruction to this therapeutic approach, but the success of CAR-T-cell therapy for the treatment of B-cell acute lymphoblastic leukaemia (B-ALL) has demonstrated that CAR T cells can be produced efficiently and for a reasonable cost.
CD19-targeted CAR T cells have been investigated clinically for the treatment of B-cell malignancies. CD19-targeted CAR-T-cell therapy has repeatedly demonstrated to produce marked antitumour responses in patients with B-ALL1, 2, 3. Following this success, much attention has been devoted to the development of CAR T cells for the successful treatment of other haematological malignancies and solid tumours. In this Review, we discuss successful CD19-targeted CAR-T-cell therapies, CAR-T-cell designs targeting other molecules for the treatment of haematological malignancies, and novel targets proposed for the treatment of solid tumours. This discussion will be limited to approaches with registered clinical trials. In our opinion, the findings from these trials will be instrumental to increase our understanding and optimize the efficacy of this promising cancer treatment.
Can advanced-stage ovarian cancer be cured?
Nature Reviews Clinical Oncology | Perspectives | Opinion
Can advanced-stage ovarian cancer be cured?
Steven Narod Nature Reviews Clinical Oncology 13,255–261(2016)doi:10.1038/nrclinonc.2015.224
Abstract
Approximately 20% of women with advanced-stage ovarian cancer survive beyond 12 years after treatment and are effectively cured. Initial therapy for ovarian cancer comprises surgery and chemotherapy, and is given with the goal of eradicating as many cancer cells as possible.
Indeed, the three phases of therapy are as follows: debulking surgery to remove as much of the cancer as possible, preferably to a state of no visible residual disease; chemotherapy to eradicate any microscopic disease that remains present after surgery; and second-line or maintenance therapy, which is given to delay disease progression among patients with tumour recurrence.
If no cancer cells remain after initial therapy is completed, a cure is expected. By contrast, if residual cancer cells are present after initial treatment, then disease recurrence is likely.
Thus, the probability of cure is contingent on the combination of surgery and chemotherapy effectively eliminating all cancer cells. In this Perspectives article, I present the case that the probability of achieving a cancer-free state is maximized through a combination of maximal debulking surgery and intraperitoneal chemotherapy.
I discuss the evidence indicating that by taking this approach, cures could be achieved in up to 50% of women with advanced-stage ovarian cancer.
Can advanced-stage ovarian cancer be cured?
Steven Narod Nature Reviews Clinical Oncology 13,255–261(2016)doi:10.1038/nrclinonc.2015.224
Abstract
Approximately 20% of women with advanced-stage ovarian cancer survive beyond 12 years after treatment and are effectively cured. Initial therapy for ovarian cancer comprises surgery and chemotherapy, and is given with the goal of eradicating as many cancer cells as possible.
Indeed, the three phases of therapy are as follows: debulking surgery to remove as much of the cancer as possible, preferably to a state of no visible residual disease; chemotherapy to eradicate any microscopic disease that remains present after surgery; and second-line or maintenance therapy, which is given to delay disease progression among patients with tumour recurrence.
If no cancer cells remain after initial therapy is completed, a cure is expected. By contrast, if residual cancer cells are present after initial treatment, then disease recurrence is likely.
Thus, the probability of cure is contingent on the combination of surgery and chemotherapy effectively eliminating all cancer cells. In this Perspectives article, I present the case that the probability of achieving a cancer-free state is maximized through a combination of maximal debulking surgery and intraperitoneal chemotherapy.
I discuss the evidence indicating that by taking this approach, cures could be achieved in up to 50% of women with advanced-stage ovarian cancer.
Gleason score at initial diagnosis and the efficacy of abiraterone acetate
Does Gleason score at initial diagnosis predict efficacy of abiraterone acetate therapy in patients with metastatic castration-resistant prostate cancer? An analysis of abiraterone acetate phase III trials
K. Fizazi1,*, T. W. Flaig2, M. Stöckle3, H. I. Scher4, J. S. de Bono5, D. E. Rathkopf4, C. J. Ryan6, T. Kheoh7, J. Li8, M. B. Todd9, T. W. Griffin10, A. Molina11 and C. H. Ohlmann3
↵*Correspondence to: Prof. Karim Fizazi, Department of Cancer Medicine, Institut Gustave Roussy, 114 Rue Edouard Vaillant, 94800 Villejuif, France. Tel: +33-1-42-11-43-17; E-mail: karim.fizazi@igr.fr
Abstract
Background The usefulness of Gleason score (<8 or ≥8) at initial diagnosis as a predictive marker of response to abiraterone acetate (AA) plus prednisone in patients with metastatic castration-resistant prostate cancer (mCRPC) was explored retrospectively.
Patients and Methods
Initial diagnosis Gleason score was obtained in 1048 of 1195 (COU-AA-301, post-docetaxel) and 996 of 1088 (COU-AA-302, chemotherapy-naïve) patients treated with AA 1 g plus prednisone 5 mg twice daily by mouth or placebo plus prednisone. Efficacy end points included radiographic progression-free survival (rPFS) and overall survival (OS). Distributions and medians were estimated by Kaplan–Meier method and hazard ratio (HR) and 95% confidence interval (CI) by Cox model.
Results
Baseline characteristics were similar across studies and treatment groups. Regardless of Gleason score, AA treatment significantly improved rPFS in post-docetaxel [Gleason score <8: median, 6.4 versus 5.5 months (HR = 0.70; 95% CI 0.56–0.86), P = 0.0009 and Gleason score ≥8: median, 5.6 versus 2.9 months (HR = 0.58; 95% CI 0.48–0.72), P < 0.0001] and chemotherapy-naïve patients [Gleason score <8: median, 16.5 versus 8.2 months (HR = 0.50; 95% CI 0.40–0.62), P < 0.0001 and Gleason score ≥8: median, 13.8 versus 8.2 months (HR = 0.61; 95% CI 0.49–0.76), P < 0.0001]. Clinical benefit of AA treatment was also observed for OS, prostate-specific antigen (PSA) response, objective response and time to PSA progression across studies and Gleason score subgroups. Conclusion
OS and rPFS trends demonstrate AA treatment benefit in patients with pre- or post-chemotherapy mCRPC regardless of Gleason score at initial diagnosis. The initial diagnostic Gleason score in patients with mCRPC should not be considered in the decision to treat with AA, as tumour metastases may no longer reflect the histology at the time of diagnosis.
Clinical trials number COU-AA-301 (NCT00638690); COU-AA-302 (NCT00887198).
K. Fizazi1,*, T. W. Flaig2, M. Stöckle3, H. I. Scher4, J. S. de Bono5, D. E. Rathkopf4, C. J. Ryan6, T. Kheoh7, J. Li8, M. B. Todd9, T. W. Griffin10, A. Molina11 and C. H. Ohlmann3
↵*Correspondence to: Prof. Karim Fizazi, Department of Cancer Medicine, Institut Gustave Roussy, 114 Rue Edouard Vaillant, 94800 Villejuif, France. Tel: +33-1-42-11-43-17; E-mail: karim.fizazi@igr.fr
Abstract
Background The usefulness of Gleason score (<8 or ≥8) at initial diagnosis as a predictive marker of response to abiraterone acetate (AA) plus prednisone in patients with metastatic castration-resistant prostate cancer (mCRPC) was explored retrospectively.
Patients and Methods
Initial diagnosis Gleason score was obtained in 1048 of 1195 (COU-AA-301, post-docetaxel) and 996 of 1088 (COU-AA-302, chemotherapy-naïve) patients treated with AA 1 g plus prednisone 5 mg twice daily by mouth or placebo plus prednisone. Efficacy end points included radiographic progression-free survival (rPFS) and overall survival (OS). Distributions and medians were estimated by Kaplan–Meier method and hazard ratio (HR) and 95% confidence interval (CI) by Cox model.
Results
Baseline characteristics were similar across studies and treatment groups. Regardless of Gleason score, AA treatment significantly improved rPFS in post-docetaxel [Gleason score <8: median, 6.4 versus 5.5 months (HR = 0.70; 95% CI 0.56–0.86), P = 0.0009 and Gleason score ≥8: median, 5.6 versus 2.9 months (HR = 0.58; 95% CI 0.48–0.72), P < 0.0001] and chemotherapy-naïve patients [Gleason score <8: median, 16.5 versus 8.2 months (HR = 0.50; 95% CI 0.40–0.62), P < 0.0001 and Gleason score ≥8: median, 13.8 versus 8.2 months (HR = 0.61; 95% CI 0.49–0.76), P < 0.0001]. Clinical benefit of AA treatment was also observed for OS, prostate-specific antigen (PSA) response, objective response and time to PSA progression across studies and Gleason score subgroups. Conclusion
OS and rPFS trends demonstrate AA treatment benefit in patients with pre- or post-chemotherapy mCRPC regardless of Gleason score at initial diagnosis. The initial diagnostic Gleason score in patients with mCRPC should not be considered in the decision to treat with AA, as tumour metastases may no longer reflect the histology at the time of diagnosis.
Clinical trials number COU-AA-301 (NCT00638690); COU-AA-302 (NCT00887198).
domingo, 27 de marzo de 2016
Addition of docetaxel, zoledronic acid, or both to first-line long-term hormone therapy in prostate cance
Volume 387, No. 10024, p1163–1177, 19 March 2016
Articles
Addition of docetaxel, zoledronic acid, or both to first-line long-term hormone therapy in prostate cancer (STAMPEDE): survival results from an adaptive, multiarm, multistage, platform randomised controlled trial
Prof Nicholas D James, PhD, Matthew R Sydes, MSccorrespondenceemail, Prof Noel W Clarke, ChM, Prof Malcolm D Mason, MD, Prof David P Dearnaley, MD, Melissa R Spears, MSc, Alastair W S Ritchie, MD, Christopher C Parker, MD, J Martin Russell, FRCR, Gerhardt Attard, MD PhD, Prof Johann de Bono, PhD, William Cross, PhD, Prof Rob J Jones, PhD, Prof George Thalmann, MD, Claire Amos, PhD, David Matheson, PhD, Robin Millman, Mymoona Alzouebi, FRCR, Sharon Beesley, FRCR, Alison J Birtle, MD, Susannah Brock, FRCR, Richard Cathomas, MD, Prabir Chakraborti, FRCR, Simon Chowdhury, MD, Audrey Cook, FRCR, Tony Elliott, PhD, Joanna Gale, DM, Stephanie Gibbs, FRCR, John D Graham, FRCP, John Hetherington, FRCS[Eng], Robert Hughes, FRCR, Robert Laing, FRCR, Fiona McKinna, FRCR, Duncan B McLaren, FRCR, FRCP[Ed], Prof Joe M O'Sullivan, MD, Omi Parikh, FRCR, Clive Peedell, FRCR, Andrew Protheroe, PhD, Angus J Robinson, FRCR, Narayanan Srihari, MD, Rajaguru Srinivasan, FRCR, John Staffurth, MD, Santhanam Sundar, FRCR, Shaun Tolan, MD, David Tsang, MCRP, Prof John Wagstaff, MD, Prof Mahesh K B Parmar, DPhil for the STAMPEDE investigators†
†Members listed at end of paper
Show all authors
Published Online: 21 December 2015
Summary
Background
Long-term hormone therapy has been the standard of care for advanced prostate cancer since the 1940s. STAMPEDE is a randomised controlled trial using a multiarm, multistage platform design. It recruits men with high-risk, locally advanced, metastatic or recurrent prostate cancer who are starting first-line long-term hormone therapy. We report primary survival results for three research comparisons testing the addition of zoledronic acid, docetaxel, or their combination to standard of care versus standard of care alone.
Methods
Standard of care was hormone therapy for at least 2 years; radiotherapy was encouraged for men with N0M0 disease to November, 2011, then mandated; radiotherapy was optional for men with node-positive non-metastatic (N+M0) disease. Stratified randomisation (via minimisation) allocated men 2:1:1:1 to standard of care only (SOC-only; control), standard of care plus zoledronic acid (SOC + ZA), standard of care plus docetaxel (SOC + Doc), or standard of care with both zoledronic acid and docetaxel (SOC + ZA + Doc). Zoledronic acid (4 mg) was given for six 3-weekly cycles, then 4-weekly until 2 years, and docetaxel (75 mg/m2) for six 3-weekly cycles with prednisolone 10 mg daily. There was no blinding to treatment allocation. The primary outcome measure was overall survival. Pairwise comparisons of research versus control had 90% power at 2·5% one-sided α for hazard ratio (HR) 0·75, requiring roughly 400 control arm deaths. Statistical analyses were undertaken with standard log-rank-type methods for time-to-event data, with hazard ratios (HRs) and 95% CIs derived from adjusted Cox models. This trial is registered at ClinicalTrials.gov (NCT00268476) and ControlledTrials.com (ISRCTN78818544).
Findings
2962 men were randomly assigned to four groups between Oct 5, 2005, and March 31, 2013. Median age was 65 years (IQR 60–71). 1817 (61%) men had M+ disease, 448 (15%) had N+/X M0, and 697 (24%) had N0M0. 165 (6%) men were previously treated with local therapy, and median prostate-specific antigen was 65 ng/mL (IQR 23–184). Median follow-up was 43 months (IQR 30–60). There were 415 deaths in the control group (347 [84%] prostate cancer). Median overall survival was 71 months (IQR 32 to not reached) for SOC-only, not reached (32 to not reached) for SOC + ZA (HR 0·94, 95% CI 0·79–1·11; p=0·450), 81 months (41 to not reached) for SOC + Doc (0·78, 0·66–0·93; p=0·006), and 76 months (39 to not reached) for SOC + ZA + Doc (0·82, 0·69–0·97; p=0·022). There was no evidence of heterogeneity in treatment effect (for any of the treatments) across prespecified subsets. Grade 3–5 adverse events were reported for 399 (32%) patients receiving SOC, 197 (32%) receiving SOC + ZA, 288 (52%) receiving SOC + Doc, and 269 (52%) receiving SOC + ZA + Doc.
Interpretation
Zoledronic acid showed no evidence of survival improvement and should not be part of standard of care for this population. Docetaxel chemotherapy, given at the time of long-term hormone therapy initiation, showed evidence of improved survival accompanied by an increase in adverse events. Docetaxel treatment should become part of standard of care for adequately fit men commencing long-term hormone therapy.
Articles
Addition of docetaxel, zoledronic acid, or both to first-line long-term hormone therapy in prostate cancer (STAMPEDE): survival results from an adaptive, multiarm, multistage, platform randomised controlled trial
Prof Nicholas D James, PhD, Matthew R Sydes, MSccorrespondenceemail, Prof Noel W Clarke, ChM, Prof Malcolm D Mason, MD, Prof David P Dearnaley, MD, Melissa R Spears, MSc, Alastair W S Ritchie, MD, Christopher C Parker, MD, J Martin Russell, FRCR, Gerhardt Attard, MD PhD, Prof Johann de Bono, PhD, William Cross, PhD, Prof Rob J Jones, PhD, Prof George Thalmann, MD, Claire Amos, PhD, David Matheson, PhD, Robin Millman, Mymoona Alzouebi, FRCR, Sharon Beesley, FRCR, Alison J Birtle, MD, Susannah Brock, FRCR, Richard Cathomas, MD, Prabir Chakraborti, FRCR, Simon Chowdhury, MD, Audrey Cook, FRCR, Tony Elliott, PhD, Joanna Gale, DM, Stephanie Gibbs, FRCR, John D Graham, FRCP, John Hetherington, FRCS[Eng], Robert Hughes, FRCR, Robert Laing, FRCR, Fiona McKinna, FRCR, Duncan B McLaren, FRCR, FRCP[Ed], Prof Joe M O'Sullivan, MD, Omi Parikh, FRCR, Clive Peedell, FRCR, Andrew Protheroe, PhD, Angus J Robinson, FRCR, Narayanan Srihari, MD, Rajaguru Srinivasan, FRCR, John Staffurth, MD, Santhanam Sundar, FRCR, Shaun Tolan, MD, David Tsang, MCRP, Prof John Wagstaff, MD, Prof Mahesh K B Parmar, DPhil for the STAMPEDE investigators†
†Members listed at end of paper
Show all authors
Published Online: 21 December 2015
Summary
Background
Long-term hormone therapy has been the standard of care for advanced prostate cancer since the 1940s. STAMPEDE is a randomised controlled trial using a multiarm, multistage platform design. It recruits men with high-risk, locally advanced, metastatic or recurrent prostate cancer who are starting first-line long-term hormone therapy. We report primary survival results for three research comparisons testing the addition of zoledronic acid, docetaxel, or their combination to standard of care versus standard of care alone.
Methods
Standard of care was hormone therapy for at least 2 years; radiotherapy was encouraged for men with N0M0 disease to November, 2011, then mandated; radiotherapy was optional for men with node-positive non-metastatic (N+M0) disease. Stratified randomisation (via minimisation) allocated men 2:1:1:1 to standard of care only (SOC-only; control), standard of care plus zoledronic acid (SOC + ZA), standard of care plus docetaxel (SOC + Doc), or standard of care with both zoledronic acid and docetaxel (SOC + ZA + Doc). Zoledronic acid (4 mg) was given for six 3-weekly cycles, then 4-weekly until 2 years, and docetaxel (75 mg/m2) for six 3-weekly cycles with prednisolone 10 mg daily. There was no blinding to treatment allocation. The primary outcome measure was overall survival. Pairwise comparisons of research versus control had 90% power at 2·5% one-sided α for hazard ratio (HR) 0·75, requiring roughly 400 control arm deaths. Statistical analyses were undertaken with standard log-rank-type methods for time-to-event data, with hazard ratios (HRs) and 95% CIs derived from adjusted Cox models. This trial is registered at ClinicalTrials.gov (NCT00268476) and ControlledTrials.com (ISRCTN78818544).
Findings
2962 men were randomly assigned to four groups between Oct 5, 2005, and March 31, 2013. Median age was 65 years (IQR 60–71). 1817 (61%) men had M+ disease, 448 (15%) had N+/X M0, and 697 (24%) had N0M0. 165 (6%) men were previously treated with local therapy, and median prostate-specific antigen was 65 ng/mL (IQR 23–184). Median follow-up was 43 months (IQR 30–60). There were 415 deaths in the control group (347 [84%] prostate cancer). Median overall survival was 71 months (IQR 32 to not reached) for SOC-only, not reached (32 to not reached) for SOC + ZA (HR 0·94, 95% CI 0·79–1·11; p=0·450), 81 months (41 to not reached) for SOC + Doc (0·78, 0·66–0·93; p=0·006), and 76 months (39 to not reached) for SOC + ZA + Doc (0·82, 0·69–0·97; p=0·022). There was no evidence of heterogeneity in treatment effect (for any of the treatments) across prespecified subsets. Grade 3–5 adverse events were reported for 399 (32%) patients receiving SOC, 197 (32%) receiving SOC + ZA, 288 (52%) receiving SOC + Doc, and 269 (52%) receiving SOC + ZA + Doc.
Interpretation
Zoledronic acid showed no evidence of survival improvement and should not be part of standard of care for this population. Docetaxel chemotherapy, given at the time of long-term hormone therapy initiation, showed evidence of improved survival accompanied by an increase in adverse events. Docetaxel treatment should become part of standard of care for adequately fit men commencing long-term hormone therapy.
martes, 22 de marzo de 2016
A locked nucleic acid antisense oligonucleotide to exon 4 of the androgen receptor mRNA in patients with castration-resistant prostate cancer
British Journal of Cancer (2013) 109, 2579–2586. doi:10.1038/bjc.2013.619 www.bjcancer.com
Published online 29 October 2013
First-in-human Phase I study of EZN-4176, a locked nucleic acid antisense oligonucleotide to exon 4 of the androgen receptor mRNA in patients with castration-resistant prostate cancer
D Bianchini1,2, A Omlin1,2, C Pezaro1,2, D Lorente1,2, R Ferraldeschi1,2, D Mukherji1,2, M Crespo1,2, I Figueiredo1,2, S Miranda1,2, R Riisnaes1,2, A Zivi1,2, A Buchbinder1,2, D E Rathkopf1,2, G Attard1,2, H I Scher1,2, J de Bono1,2,3,4 and D C Danila1,2,3,4
1Prostate Cancer Targeted Therapy Group and Drug Development Unit, Royal Marsden NHS Foundation Trust and The Institute of Cancer Research, Downs Road, Sutton, Surrey, UK
2Memorial Sloan-Kettering Cancer Center (MSKCC) and Weill Cornell Medical College, Center for Prostate and Urologic Cancers, New York, NY, USA
3ENZON Pharmaceuticals Inc.; Bridgewater, NJ, USA
Correspondence: Professor J de Bono, E-mail: johann.de-bono@icr.ac.uk
Abstract
Background:
Prostate cancer remains dependent of androgen receptor (AR) signalling, even after emergence of castration resistance. EZN-4176 is a third-generation antisense oligonucleotide that binds to the hinge region (exon 4) of AR mRNA resulting in full-length AR mRNA degradation and decreased AR protein expression. This Phase I study aimed to evaluate EZN-4176 in men with castration-resistant prostate cancer (CRPC).
Methods:
Patients with progressing CRPC were eligible; prior abiraterone and enzalutamide treatment were allowed. EZN-4176 was administered as a weekly (QW) 1-h intravenous infusion. The starting dose was 0.5 mg kg−1 with a 4-week dose-limiting toxicity (DLT) period and a 3+3 modified Fibonacci dose escalation design. After determination of the DLT for weekly administration, an every 2 weeks schedule was initiated.
Results:
A total of 22 patients were treated with EZN-4176. At 10 mg kg−1 QW, two DLTs were observed due to grade 3–4 ALT or AST elevation. No confirmed biochemical or soft tissue responses were observed. Of eight patients with greater than or equal to5 circulating tumour cells at baseline, a conversion to <5 was observed in three (38%) patients. The most common EZN-4176-related toxicities (all grades) were fatigue (59%), reversible abnormalities in liver function tests ALT (41%) and AST (41%) and infusion-related reactions including chills (36%) and pyrexia (14%).
Conclusion:
Activity of EZN-4176 at the doses and schedules explored was minimal. The highest dose of 10 mg kg−1 QW was associated with significant but reversible transaminase elevation.
Keywords:
castration-resistant prostate cancer; EZN-4176; antisense oligonucleotide; phase I clinical trial
Published online 29 October 2013
First-in-human Phase I study of EZN-4176, a locked nucleic acid antisense oligonucleotide to exon 4 of the androgen receptor mRNA in patients with castration-resistant prostate cancer
D Bianchini1,2, A Omlin1,2, C Pezaro1,2, D Lorente1,2, R Ferraldeschi1,2, D Mukherji1,2, M Crespo1,2, I Figueiredo1,2, S Miranda1,2, R Riisnaes1,2, A Zivi1,2, A Buchbinder1,2, D E Rathkopf1,2, G Attard1,2, H I Scher1,2, J de Bono1,2,3,4 and D C Danila1,2,3,4
1Prostate Cancer Targeted Therapy Group and Drug Development Unit, Royal Marsden NHS Foundation Trust and The Institute of Cancer Research, Downs Road, Sutton, Surrey, UK
2Memorial Sloan-Kettering Cancer Center (MSKCC) and Weill Cornell Medical College, Center for Prostate and Urologic Cancers, New York, NY, USA
3ENZON Pharmaceuticals Inc.; Bridgewater, NJ, USA
Correspondence: Professor J de Bono, E-mail: johann.de-bono@icr.ac.uk
Abstract
Background:
Prostate cancer remains dependent of androgen receptor (AR) signalling, even after emergence of castration resistance. EZN-4176 is a third-generation antisense oligonucleotide that binds to the hinge region (exon 4) of AR mRNA resulting in full-length AR mRNA degradation and decreased AR protein expression. This Phase I study aimed to evaluate EZN-4176 in men with castration-resistant prostate cancer (CRPC).
Methods:
Patients with progressing CRPC were eligible; prior abiraterone and enzalutamide treatment were allowed. EZN-4176 was administered as a weekly (QW) 1-h intravenous infusion. The starting dose was 0.5 mg kg−1 with a 4-week dose-limiting toxicity (DLT) period and a 3+3 modified Fibonacci dose escalation design. After determination of the DLT for weekly administration, an every 2 weeks schedule was initiated.
Results:
A total of 22 patients were treated with EZN-4176. At 10 mg kg−1 QW, two DLTs were observed due to grade 3–4 ALT or AST elevation. No confirmed biochemical or soft tissue responses were observed. Of eight patients with greater than or equal to5 circulating tumour cells at baseline, a conversion to <5 was observed in three (38%) patients. The most common EZN-4176-related toxicities (all grades) were fatigue (59%), reversible abnormalities in liver function tests ALT (41%) and AST (41%) and infusion-related reactions including chills (36%) and pyrexia (14%).
Conclusion:
Activity of EZN-4176 at the doses and schedules explored was minimal. The highest dose of 10 mg kg−1 QW was associated with significant but reversible transaminase elevation.
Keywords:
castration-resistant prostate cancer; EZN-4176; antisense oligonucleotide; phase I clinical trial
lunes, 21 de marzo de 2016
Genomic complexity of urothelial bladder cancer revealed in urinary cfDNA
Article
European Journal of Human Genetics advance online publication 13 January 2016; doi: 10.1038/ejhg.2015.281
Genomic complexity of urothelial bladder cancer revealed in urinary cfDNA
EJHGOpen
Fiona S Togneri1, Douglas G Ward2, Joseph M Foster3, Adam J Devall2, Paula Wojtowicz1, Sofia Alyas1, Fabiana Ramos Vasques1, Assa Oumie3, Nicholas D James4, K K Cheng5, Maurice P Zeegers6, Nayneeta Deshmukh2, Brendan O'Sullivan7, Philippe Taniere7, Karen G Spink3, Dominic J McMullan1, Mike Griffiths1 and Richard T Bryan2
1West Midland Regional Genetics Laboratory, Birmingham Women’s NHS Foundation Trust, Birmingham, UK
2Institute of Cancer & Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
3Affymetrix UK Ltd, High Wycombe, UK
4Cancer Research Unit, University of Warwick, Coventry, UK
5School of Health and Population Sciences, University of Birmingham, Birmingham, UK
6Department of Complex Genetics, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, The Netherlands
7Department of Histopathology, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
Abstract
Urothelial bladder cancers (UBCs) have heterogeneous clinical characteristics that are mirrored in their diverse genomic profiles. Genomic profiling of UBCs has the potential to benefit routine clinical practice by providing prognostic utility above and beyond conventional clinicopathological factors, and allowing for prediction and surveillance of treatment responses. Urinary DNAs representative of the tumour genome provide a promising resource as a liquid biopsy for non-invasive genomic profiling of UBCs. We compared the genomic profiles of urinary cellular DNA and cell-free DNA (cfDNA) from the urine with matched diagnostic formalin-fixed paraffin-embedded tumour DNAs for 23 well-characterised UBC patients. Our data show urinary DNAs to be highly representative of patient tumours, allowing for detection of recurrent clinically actionable genomic aberrations. Furthermore, a greater aberrant load (indicative of tumour genome) was observed in cfDNA over cellular DNA (P<0.001), resulting in a higher analytical sensitivity for detection of clinically actionable genomic aberrations (P<0.04) when using cfDNA. Thus, cfDNA extracted from the urine of UBC patients has a higher tumour genome burden and allows greater detection of key genomic biomarkers (90%) than cellular DNA from urine (61%) and provides a promising resource for robust whole-genome tumour profiling of UBC with potential to influence clinical decisions without invasive patient interventions. Introduction
Urothelial bladder cancer (UBC) is the seventh most common cancer in Western societies with a rising global incidence.
1 Disease management poses numerous challenges because of the following:
(i) the propensity for non-muscle-invasive bladder cancer (NMIBC) to recur, necessitating long-term surveillance;
(ii) a variable risk of NMIBC progression, associated with poor 5-year survival;2, 3
(iii) a lack of proven biomarker prognosticators to identify those subsets of patients who will suffer tumour recurrence, progression and death; and (iv) the radical therapies required to treat muscle-invasive disease (MIBC).4 UBCs are thus highly heterogeneous in their clinical characteristics and this is mirrored in their genomics, characteristics of which traverse conventional grade and stage groupings.5
Typically, genomic aberrations in tumours have been characterised using formalin-fixed paraffin-embedded (FFPE) or fresh-frozen tumour tissue, with such analyses elucidating promising biomarkers and suggesting genomic signatures with potential to influence future therapeutic interventions.6, 7, 8 Identifying such genomic complexity in a non-invasive manner could be highly advantageous for facilitating the diagnosis, treatment and surveillance of patients with NMIBC or MIBC.9, 10
Genetic changes in UBCs have previously been investigated non-invasively using genetic material present in the urine. Both genetic material from exfoliated cells (which pellet upon centrifugation) and cell-free DNA (cfDNA; which remains in the supernatant following centrifugation) have been studied. Most studies to date have focused on exfoliated cells, with data giving a specific read out, for example, the presence or absence of UBC.11 Urine tests looking at genomic copy number (CN) include the FISH-based UroVysion test (Abbott, Des Plaines, IL, USA; FDA-approved UBC diagnosis),12 which uses individual exfoliated tumour cells isolated from urine, and the CGH-based BCA-1 test, which uses DNA extracted from these exfoliated cells. BCA-1 has been used to examine more detailed CN data in bladder cancer patients than that provided by UroVysion, and shows some promise.13, 14 Unfortunately, obtaining sufficient cellular material for analysis is not always possible, hindering the clinical applicability of such tests. A small number of studies have therefore also investigated urinary cfDNA for UBC analysis with mixed results, and it has previously been suggested that due to its origin, cfDNA may be enriched for tumour-specific biomarkers with reduced contamination from germline DNA of non-cancerous cells.15
cfDNA in blood plasma, arising through cancer cell death (necrotic or apoptotic cells) and actively released DNA,16, 17 has been well studied as a liquid biopsy for various solid tumours. cfDNA in urine of bladder cancer patients has also been studied in this setting.15 This nucleic acid resource has been proposed to be predominantly necrotic in origin and quantitative changes in necrotic-specific cfDNA levels have been studied to discriminate between cancer and non-cancer patients.18
In this study, we report the utilisation of Affymetrix’s OncoScan FFPE Assay Kit (Affymetrix, Santa Clara, CA, USA) for detailed genomic profiling of UBC using matched FFPE tumour-derived DNA, cellular DNA from urine cell pellets and cfDNA from urine supernatant. We demonstrate that the complex genomics and important clinically actionable aberrations that are evident in FFPE tumour material (currently the predominant diagnostic biospecimen for solid tumours) are echoed in urinary DNAs, and that the tumour genome is enriched in cfDNA compared with cellular DNA. These data illustrate that urinary cfDNA may represent a reliable resource for non-invasive genomic profiling of bladder cancer.
European Journal of Human Genetics advance online publication 13 January 2016; doi: 10.1038/ejhg.2015.281
Genomic complexity of urothelial bladder cancer revealed in urinary cfDNA
EJHGOpen
Fiona S Togneri1, Douglas G Ward2, Joseph M Foster3, Adam J Devall2, Paula Wojtowicz1, Sofia Alyas1, Fabiana Ramos Vasques1, Assa Oumie3, Nicholas D James4, K K Cheng5, Maurice P Zeegers6, Nayneeta Deshmukh2, Brendan O'Sullivan7, Philippe Taniere7, Karen G Spink3, Dominic J McMullan1, Mike Griffiths1 and Richard T Bryan2
1West Midland Regional Genetics Laboratory, Birmingham Women’s NHS Foundation Trust, Birmingham, UK
2Institute of Cancer & Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
3Affymetrix UK Ltd, High Wycombe, UK
4Cancer Research Unit, University of Warwick, Coventry, UK
5School of Health and Population Sciences, University of Birmingham, Birmingham, UK
6Department of Complex Genetics, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, The Netherlands
7Department of Histopathology, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
Abstract
Urothelial bladder cancers (UBCs) have heterogeneous clinical characteristics that are mirrored in their diverse genomic profiles. Genomic profiling of UBCs has the potential to benefit routine clinical practice by providing prognostic utility above and beyond conventional clinicopathological factors, and allowing for prediction and surveillance of treatment responses. Urinary DNAs representative of the tumour genome provide a promising resource as a liquid biopsy for non-invasive genomic profiling of UBCs. We compared the genomic profiles of urinary cellular DNA and cell-free DNA (cfDNA) from the urine with matched diagnostic formalin-fixed paraffin-embedded tumour DNAs for 23 well-characterised UBC patients. Our data show urinary DNAs to be highly representative of patient tumours, allowing for detection of recurrent clinically actionable genomic aberrations. Furthermore, a greater aberrant load (indicative of tumour genome) was observed in cfDNA over cellular DNA (P<0.001), resulting in a higher analytical sensitivity for detection of clinically actionable genomic aberrations (P<0.04) when using cfDNA. Thus, cfDNA extracted from the urine of UBC patients has a higher tumour genome burden and allows greater detection of key genomic biomarkers (90%) than cellular DNA from urine (61%) and provides a promising resource for robust whole-genome tumour profiling of UBC with potential to influence clinical decisions without invasive patient interventions. Introduction
Urothelial bladder cancer (UBC) is the seventh most common cancer in Western societies with a rising global incidence.
1 Disease management poses numerous challenges because of the following:
(i) the propensity for non-muscle-invasive bladder cancer (NMIBC) to recur, necessitating long-term surveillance;
(ii) a variable risk of NMIBC progression, associated with poor 5-year survival;2, 3
(iii) a lack of proven biomarker prognosticators to identify those subsets of patients who will suffer tumour recurrence, progression and death; and (iv) the radical therapies required to treat muscle-invasive disease (MIBC).4 UBCs are thus highly heterogeneous in their clinical characteristics and this is mirrored in their genomics, characteristics of which traverse conventional grade and stage groupings.5
Typically, genomic aberrations in tumours have been characterised using formalin-fixed paraffin-embedded (FFPE) or fresh-frozen tumour tissue, with such analyses elucidating promising biomarkers and suggesting genomic signatures with potential to influence future therapeutic interventions.6, 7, 8 Identifying such genomic complexity in a non-invasive manner could be highly advantageous for facilitating the diagnosis, treatment and surveillance of patients with NMIBC or MIBC.9, 10
Genetic changes in UBCs have previously been investigated non-invasively using genetic material present in the urine. Both genetic material from exfoliated cells (which pellet upon centrifugation) and cell-free DNA (cfDNA; which remains in the supernatant following centrifugation) have been studied. Most studies to date have focused on exfoliated cells, with data giving a specific read out, for example, the presence or absence of UBC.11 Urine tests looking at genomic copy number (CN) include the FISH-based UroVysion test (Abbott, Des Plaines, IL, USA; FDA-approved UBC diagnosis),12 which uses individual exfoliated tumour cells isolated from urine, and the CGH-based BCA-1 test, which uses DNA extracted from these exfoliated cells. BCA-1 has been used to examine more detailed CN data in bladder cancer patients than that provided by UroVysion, and shows some promise.13, 14 Unfortunately, obtaining sufficient cellular material for analysis is not always possible, hindering the clinical applicability of such tests. A small number of studies have therefore also investigated urinary cfDNA for UBC analysis with mixed results, and it has previously been suggested that due to its origin, cfDNA may be enriched for tumour-specific biomarkers with reduced contamination from germline DNA of non-cancerous cells.15
cfDNA in blood plasma, arising through cancer cell death (necrotic or apoptotic cells) and actively released DNA,16, 17 has been well studied as a liquid biopsy for various solid tumours. cfDNA in urine of bladder cancer patients has also been studied in this setting.15 This nucleic acid resource has been proposed to be predominantly necrotic in origin and quantitative changes in necrotic-specific cfDNA levels have been studied to discriminate between cancer and non-cancer patients.18
In this study, we report the utilisation of Affymetrix’s OncoScan FFPE Assay Kit (Affymetrix, Santa Clara, CA, USA) for detailed genomic profiling of UBC using matched FFPE tumour-derived DNA, cellular DNA from urine cell pellets and cfDNA from urine supernatant. We demonstrate that the complex genomics and important clinically actionable aberrations that are evident in FFPE tumour material (currently the predominant diagnostic biospecimen for solid tumours) are echoed in urinary DNAs, and that the tumour genome is enriched in cfDNA compared with cellular DNA. These data illustrate that urinary cfDNA may represent a reliable resource for non-invasive genomic profiling of bladder cancer.
sábado, 5 de marzo de 2016
Immunotherapy Two antigens are better than one
Nature Reviews Cancer | Research Highlight
Immunotherapy
Two antigens are better than one
Sarah Seton-Rogers
Nature Reviews Cancer 16,128–129(2016)doi:10.1038/nrc.2016.17
Published online
19 February 2016
T cells carrying chimeric antigen receptors (CARs) or engineered T cell receptors (TCRs) have shown remarkable efficacy against some tumour types, primarily B cell malignancies. However, the use of these engineered T cells is limited to tumours that express highly specific antigens; in most cases tumour antigens are also expressed in normal 'bystander' tissues, and T cells that target them can cause lethal side effects.
Jennie Vallis/NPG
One solution to increase the specificity of engineered T cells might be to design a new receptor that is independent of CAR and TCR pathways, but that can reliably activate a CAR for a second antigen.
Morsut, Roybal et al. first designed a modular receptor based on Notch (SynNotch receptor) that binds to a target antigen and then triggers receptor cleavage to release a transcriptional activation domain that can activate a target gene(s) of choice.
Roybal et al. then used this platform to design a system in which one tumour antigen activates SynNotch in T cells, thereby activating transcription of a CAR that recognizes a second tumour antigen, ultimately leading to T cell activation.
The authors designed a proof-of-concept experiment in Jurkat T cells using a SynNotch receptor that recognized CD19 and contained a tetracycline-transactivator (tTa) domain; the tTa domain then activated transcription of a tetracycline response element-driven CAR against mesothelin.
In culture, these Jurkat cells were only activated by tumour cells that expressed both CD19 and mesothelin, and not those expressing only one of these antigens.
They then designed a similar system in primary human CD4+ or CD8+ T cells. In these cells, they found that a SynNotch receptor containing the Gal4-VP64 transcriptional activation domain had low basal transcriptional activity, which is required to prevent the induction of CAR expression in the absence of the first antigen.
These cells expressed a SynNotch–Gal4-VP64 that bound green fluorescent protein (GFP) and a CAR against CD19. K562 leukaemia cells that expressed both GFP and CD19 activated these primary T cells effectively in vitro, but K562 cells lacking either antigen did not; only K562 cells expressing both antigens were killed by these engineered T cells. Similar results were observed with two different SynNotch–CAR systems in primary T cells that responded to tumour cell CD19 and mesothelin, or to GFP and mesothelin.
Primary human T cells with the GFP SynNotch and CD19 CAR also exhibited localized activation in tumours in vivo. Immunocompromised mice were injected with CD19+ Daudi B cell lymphoblastoid cells; cells injected in one flank were also GFP+. Following tumour development, engineered T cells were injected; the CD19 CAR was expressed only in T cells within GFP+ tumours. Furthermore, in a similar bilateral tumour model, the engineered T cells promoted clearance of established K562 xenografts expressing both antigens but not of bystander cells that lacked GFP. In addition, when bilateral models were established with K562 cells each expressing only CD19 or GFP, engineered SynNotch T cells were not activated, indicating that SynNotch activation by one cell and then CAR activation by another following T cell migration (which could lead to off-target side effects) does not occur.
“in principle it is possible to use this flexible, modular system to design more effective and safer T cell therapies”
Although much additional work is required before these types of T cell could be tested clinically, these results demonstrate that in principle it is possible to use this flexible, modular system to design more effective and safer T cell therapies for a wider range of tumour types.
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