Lisa M. Kopp

Membrane-bound IL-21 promotes sustained Ex Vivo proliferation of human natural killer cells

NK cells have therapeutic potential for a wide variety of human malignancies. However, because NK cells expand poorly in vitro, have limited life spans in vivo, and represent a small fraction of peripheral white blood cells, obtaining sufficient cell numbers is the major obstacle for NK-cell immunotherapy. Genetically-engineered artificial antigen-presenting cells (aAPCs) expressing membrane-bound IL-15 (mbIL15) have been used to propagate clinical-grade NK cells for human trials of adoptive immunotherapy, but ex vivo proliferation has been limited by telomere shortening. We developed K562-based aAPCs with membrane-bound IL-21 (mbIL21) and assessed their ability to support human NK-cell proliferation. In contrast to mbIL15, mbIL21-expressing aAPCs promoted log-phase NK cell expansion without evidence of senescence for up to 6 weeks of culture. By day 21, parallel expansion of NK cells from 22 donors demonstrated a mean 47,967-fold expansion (median 31,747) when co-cultured with aAPCs expressing mbIL21 compared to 825-fold expansion (median 325) with mbIL15. Despite the significant increase in proliferation, mbIL21-expanded NK cells also showed a significant increase in telomere length compared to freshly obtained NK cells, suggesting a possible mechanism for their sustained proliferation. NK cells expanded with mbIL21 were similar in phenotype and cytotoxicity to those expanded with mbIL15, with retained donor KIR repertoires and high expression of NCRs, CD16, and NKG2D, but had superior cytokine secretion. The mbIL21-expanded NK cells showed increased transcription of the activating receptor CD160, but otherwise had remarkably similar mRNA expression profiles of the 96 genes assessed. mbIL21-expanded NK cells had significant cytotoxicity against all tumor cell lines tested, retained responsiveness to inhibitory KIR ligands, and demonstrated enhanced killing via antibody-dependent cell cytotoxicity. Thus, aAPCs expressing mbIL21 promote improved proliferation of human NK cells with longer telomeres and less senescence, supporting their clinical use in propagating NK cells for adoptive immunotherapy.

Novel bone cancer drugs: investigational agents and control paradigms for primary bone sarcomas (Ewing's sarcoma and osteosarcoma).

Background: New investigational agents and chemotherapy regimens including cyclophosphamide + topotecan, temozolomide + irinotecan, and anti-IGF-1R antibodies in Ewings sarcoma (ES) and liposomal muramyltripeptide phosphatidylethanolamine (L-MTP-PE), aerosol therapy, and bone-specific agents in osteosarcoma (OS) may improve survival and/or quality of life on ‘continuation’ therapy. Objective: Review of investigational approaches and control paradigms for recurrent or metastatic primary bone tumors. Methods: Analyze temozolomide + irinotecan data and review in the context of other newer approaches including antiangiogenesis, anti-IGF-1R antibodies and bisphosphonates for ES. Review some current state-of-the-art approaches for OS including L-MTP-PE, anti-IGF-1R inhibition, aerosol therapies and bone specific agents. Results/conclusion: L-MTP-PE with chemotherapy in OS has been shown to improve survival; compassionate access is available for recurrence and/or metastases. Aerosol therapy (granulocyte–macrophage colony stimulating factor, cisplatin, gemcitabine) for lung metastases is a promising approach to reduce systemic toxicity. The bone-specific agents including denosumab (anti-receptor activator of NF-κB ligand antibody) and bisphosphonates may have benefit against giant cell tumor, ES and OS. Anti-IGF-1R antibody SCH717454 has preclinical activity in OS but best effectiveness will most likely be in combination with chemotherapy earlier in therapy. Both temozolomide + irinotecan and cyclophosphamide + topotecan combinations are very active in ES and are likely to be tested with anti-IGF-1R antibodies against ES.

Late effects in adult survivors of pediatric cancer: A guide for the primary care physician

Because of significant medical advances in the past 50 years, the number of adult survivors of childhood/adolescent cancer has increased dramatically. Unfortunately, more than 60% of these survivors will have at least 1 long-term side effect from treatment. This growing population requires dedicated care by their primary physicians because they have specific risk factors depending on their initial cancer diagnosis and the treatment modalities they received. Internists and family physicians play an integral role in providing appropriate screening, treatment, and counseling to prevent morbidity and mortality in these patients.

All-trans-retinoic acid and arsenic trioxide as initial therapy for acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) is a rare subtype of acute myeloid leukemia (AML). Treatment of pediatric APL is based on the combination of all‐trans‐retinoic acid (ATRA), an anthracycline and cytosine arabinoside. Arsenic trioxide (ATO) has been studied in adults with newly diagnosed or relapsed APL with excellent response rates both when used as a single agent or in combination with ATRA or ATRA plus chemotherapy. There is little data on combination therapy with ATRA and ATO in pediatric APL. We present a case of an adolescent male with APL who was treated using ATRA and ATO without conventional chemotherapy agents. Pediatr Blood Cancer 2008;51:133–135.

Incidence of delirium in children with cancer.

There are limited data on the incidence of delirium in children with cancer. We performed a retrospective chart review of all pediatric oncology admissions over a 1 year period to determine the incidence of delirium in this population. We identified seven patients with delirium (10% incidence). Delirium is associated with significant morbidity and mortality, and is likely under‐recognized in this population. Improved diagnosis and treatment of delirium may improve outcomes in children with cancer. Pediatr Blood Cancer 2014;61:2094–2095.

Lifestyle behavior interventions delivered using technology in childhood, adolescent, and young adult cancer survivors: A systematic review.

Childhood, adolescent, and young adult cancer survivors demonstrate increased cardio‐metabolic risk factors, which are amenable to lifestyle changes. The use of technology to impact lifestyle change expands previously limited intervention access, yet little is known about its use. We summarized lifestyle interventions for survivors delivered using technology, finding six studies, primarily targeting physical activity. Study samples were small and durations ranged from 5 to 16 weeks and outcomes modest. Participants were older, white, survivors of leukemia or brain tumors, and the majority received Web‐based interventions. Study quality was moderate. Few technology‐based interventions have been developed, suggesting an area of opportunity for survivors.

Utility of bone marrow aspiration and biopsy in initial staging of Ewing sarcoma

The current standard of care for initial staging of pediatric Ewing sarcoma (EWS) patients is to obtain a bilateral bone marrow aspiration and biopsy (BMAB). The incidence of bone marrow (BM) disease in patients deemed non‐metastatic by conventional and metabolic imaging and the concordance of BM positivity with other clinical characteristics are not well established.

Clinical trial enrollment of adolescents and young adults with sarcoma

More than half of all sarcomas occur in adolescents and young adults (AYAs) aged 15 to 39 years. After the publication of the AYA series in the April 1, 2016 issue of Cancer, several leaders in the field of sarcoma across disciplines gathered to discuss the status of sarcoma clinical research in AYAs. They determined that a focused effort to include the underrepresented and understudied AYA population in current and future sarcoma clinical trials is overdue. Trial enrichment for AYA‐aged sarcoma patients will produce more meaningful results that better represent the diseases biology, epidemiology, and treatment environment. To address the current deficit, this commentary outlines changes believed to be necessary to expediently achieve an increase in the enrollment of AYAs in sarcoma clinical trials. Cancer 2017;123:3434‐40.

Targeted immunotherapy for pediatric solid tumors

ABSTRACT Metastatic and refractory pediatric solid tumor malignancies continue to have a poor outcome despite the > 80% cure rates appreciated in many pediatric cancers. Targeted immunotherapy is impacting treatment and survival in these aggressive tumors. We review current promising immunotherapeutic approaches in the pediatric oncology solid tumor setting.

Alternative Donor Hematopoietic Cell Transplantation Conditioned With Myeloablative Busulfan, Fludarabine, and Melphalan is Well Tolerated and Effective Against High-risk Myeloid Malignancies.

Busulfan, fludarabine, and melphalan as hematopoietic cell transplant conditioning, was used in 6 patients aged 1 to 19 years with very high-risk myeloid malignancies. This dose regimen had an acceptable toxicity profile resulting in complete donor engraftment even following transplantation of small 2/6 antigen disparate umbilical cord blood grafts. It provided excellent disease control as all patients had high-risk features in terms of cytogenetics, therapy-related leukemia, and/or significant measurable disease before transplant. All patients remain in remission, without acute or chronic graft-versus-host disease with a median follow-up of 24 months. A larger study is indicated to confirm the efficacy and safety of this regimen.