Paediatric Strategy Forum for medicinal product development of chimeric antigen receptor T-cells in children and adolescents with cancer: ACCELERATE in collaboration with the European Medicines Agency with participation of the Food and Drug Administration.

The seventh multi-stakeholder Paediatric Strategy Forum focused on chimeric antigen receptor (CAR) T-cells for children and adolescents with cancer. The development of CAR T-cells for patients with haematological malignancies, especially B-cell precursor acute lymphoblastic leukaemia (BCP-ALL), has been spectacular. However, currently, there are scientific, clinical and logistical challenges for use of CAR T-cells in BCP-ALL and other paediatric malignancies, particularly in acute myeloid leukaemia (AML), lymphomas and solid tumours. The aims of the Forum were to summarise the current landscape of CAR T-cell therapy development in paediatrics, too identify current challenges and future directions, with consideration of other immune effector modalities and ascertain the best strategies to accelerate their development and availability to children. Although the effect is of limited duration in about half of the patients, anti-CD19 CAR T-cells produce high response rates in relapsed/refractory BCP-ALL and this has highlighted previously unknown mechanisms of relapse. CAR T-cell treatment as first- or second-line therapy could also potentially benefit patients whose disease has high-risk features associated with relapse and failure of conventional therapies. Identifying patients with very early and early relapse in whom CAR T-cell therapy may replace haematopoietic stem cell transplantation and be definitive therapy versus those in whom it provides a more effective bridge to haematopoietic stem cell transplantation is a very high priority. Development of approaches to improve persistence, either by improving T cell fitness or using more humanised/fully humanised products and co-targeting of multiple antigens to prevent antigen escape, could potentially further optimise therapy. Many differences exist between paediatric B-cell non-Hodgkin lymphomas (B-NHL) and BCP-ALL. In view of the very small patient numbers with relapsed lymphoma, careful prioritisation is needed to evaluate CAR T-cells in children with Burkitt lymphoma, primary mediastinal B cell lymphoma and other NHL subtypes. Combination trials of alternative targets to CD19 (CD20 or CD22) should also be explored as a priority to improve efficacy in this population. Development of CD30 CAR T-cell immunotherapy strategies in patients with relapsed/refractory Hodgkin lymphoma will likely be most efficiently accomplished by joint paediatric and adult trials. CAR T-cell approaches are early in development for AML and T-ALL, given the unique challenges of successful immunotherapy actualisation in these diseases. At this time, CD33 and CD123 appear to be the most universal targets in AML and CD7 in T-ALL. The results of ongoing or planned first-in-human studies are required to facilitate further understanding. There are promising early results in solid tumours, particularly with GD2 targeting cell therapies in neuroblastoma and central nervous system gliomas that represent significant unmet clinical needs. Further understanding of biology is critical to success. The comparative benefits of autologous versus allogeneic CAR T-cells, T-cells engineered with T cell receptors T-cells engineered with T cell receptor fusion constructs, CAR Natural Killer (NK)-cell products, bispecific T-cell engager antibodies and antibody-drug conjugates require evaluation in paediatric malignancies. Early and proactive academia and multi-company engagement are mandatory to advance cellular immunotherapies in paediatric oncology. Regulatory advice should be sought very early in the design and preparation of clinical trials of innovative medicines, for which regulatory approval may ultimately be sought. Aligning strategic, scientific, regulatory, health technology and funding requirements from the inception of a clinical trial is especially important as these are very expensive therapies. The model for drug development for cell therapy in paediatric oncology could also involve a 'later stage handoff' to industry after early development in academic hands. Finally, and very importantly, strategies must evolve to ensure appropriate ease of access for children who need and could potentially benefit from these therapies.

Outcomes for Asian patients with multiple myeloma receiving once- or twice-weekly carfilzomib-based therapy: a subgroup analysis of the randomized phase 3 ENDEAVOR and A.R.R.O.W. Trials.

Carfilzomib is an irreversible proteasome inhibitor used for the treatment of relapsed and/or refractory multiple myeloma (RRMM). We evaluated the efficacy and safety of carfilzomib in subgroups of Asian patients in the randomized phase 3 ENDEAVOR and A.R.R.O.W. trials. In ENDEAVOR, patients received carfilzomib twice-weekly (56 mg/m2) plus dexamethasone (Kd; n = 56) or bortezomib plus dexamethasone (Vd; n = 57). In A.R.R.O.W., patients received carfilzomib once-weekly (70 mg/m2, n = 30) or twice-weekly (27 mg/m2, n = 15) plus dexamethasone. Median progression-free survival (PFS) among Asian patients in ENDEAVOR was longer with Kd than with Vd (14.9 versus 8.8 months; HR 0.599); the overall response rate (ORR) was 80.4% versus 70.2%. Median overall survival (Kd versus Vd) was 47.6 versus 38.8 months (HR 0.856). Median PFS among Asian patients in A.R.R.O.W. was longer for once-weekly versus twice-weekly Kd (16.0 versus 8.4 months; HR 0.628); ORR was 76.7% versus 53.3%. Rates of grade ≥ 3 adverse events were 89.1% (Kd) and 89.5% (Vd) in ENDEAVOR, and 76.6% (once-weekly Kd) versus 73.3% (twice-weekly Kd) in A.R.R.O.W. Overall, carfilzomib had a favorable benefit-risk profile across both dosing regimens [once-weekly (Kd 70 mg/m2) and twice-weekly (Kd 56 mg/m2)] in Asian patients with RRMM, which was consistent with the results of both parent studies.Trial registration ClinicalTrials.gov: NCT01568866, NCT02412878.

Lower exposure and faster clearance of bevacizumab in gastric cancer and the impact of patient variables: analysis of individual data from AVAGAST phase III trial.

Altered pharmacokinetics of antibody drugs has been reported in advanced gastric cancer (AGC). We aim to evaluate bevacizumab pharmacokinetics in AGC from the Phase III trial (AVAGAST), and explore the influence of patient variables. Bevacizumab concentrations (Cp) were measured in plasma samples taken following disease progression from 162 patients (7.5 mg/kg every 3 weeks). Predicted Cp [median and 90% prediction interval] was simulated using the population pharmacokinetic model established for other cancers (PPK model) and compared to observed Cp. Bevacizumab clearance was estimated using NONMEM and compared between subgroups. Patient characteristics of AGC are similar to other cancers except for lower body weight despite higher percentage of males. Eighty-five percent of observed Cp was below the median predicted Cp and 38% below the lower boundary of the 90% prediction interval. Median bevacizumab clearance in AGC was 4.5 versus 3 mL/day/kg in other cancers. Bevacizumab clearance was significantly faster (p < 0.05) in patients without gastrectomy (n = 42) or lower albumin. Clearance appeared to be faster in patients with lower total protein, higher ECOG scores, more metastatic sites, and poorer response. No significant difference in bevacizumab concentrations and clearance was observed between Asian and Non-Asian patients. AGC patients exhibited significantly lower bevacizumab exposure due to an approximate 50% increase in clearance versus other cancers. Bevacizumab is cleared faster in patients without prior gastrectomy. No significant difference in bevacizumab pharmacokinetics was observed between Asian and Non-Asian patients. The underlying mechanism for faster bevacizumab clearance in AGC is unknown and warrants further research.