CTRIP:Notch-Mediated Expansion of Cord Blood Progenitors for Cord Blood Transplan

描述（由申请人提供）：为了克服脐带血（CB）移植后发生的中性粒细胞恢复的显著延迟，我们成功开发了一种新的临床可行的方法，该方法利用工程化Notch配体离体产生增加数量的CD 34+细胞。目前正在进行一项在接受清髓性脐带血移植（CBT）的患者中利用Notch介导的扩增CB祖细胞的I期临床试验。该试验的结果不仅证明了该方法的安全性，而且更重要的是首次证明了在输注离体扩增的造血祖细胞后可以实现快速骨髓移植。在接受扩增细胞的患者中观察到达到绝对中性粒细胞计数500/<ml的中位时间显著减少至仅16天，相比之下，在接受相同治疗但使用两个未操作的CB单位的20名患者的并行队列中，中位时间为26天（p=0.002）。因此，尽管迄今为止接受治疗的患者数量较少（n=10），但已明确证明了对骨髓恢复时间的显著影响，以及该方法的安全性和临床可行性。 这种方法的进一步发展现在取决于临床疗效的确定，这将需要一个随机的多机构试验。在启动此类试验之前，需要解决几个关键问题，包括生产和安全运送细胞到外部中心的能力，建立适当的临床试验和细胞疗法生产协作组以进行未来的II期随机多机构试验，以及确定临床使用的离体扩增产品的HLA匹配需求。我们的目标是，在两年资助期结束时，我们将做好准备，并完全准备好开始关键的II期研究。 具体而言，我们现在提出以下目标：1）确定将扩增的细胞运送到外部中心进行输注的方法，包括在我们建立的小鼠模型中对所提出方法的体内再增殖能力进行临床前评价。在此之后，我们将与明尼苏达大学的John瓦格纳博士进行一项10名患者的初步研究，作为我们目前I期试验的扩展，以评估过夜运输细胞的安全性和可行性。2)在当地进行的并行初步研究中，确定是否可以输注不含T细胞的扩增细胞产品而无需HLA配型。在这项研究中，接受常规CBT的患者将接受先前从新鲜CB单元扩增的CB祖细胞，然后冷冻保存以供将来作为“现成”产品使用。如果成功，这将大大增加患者对该产品的使用。3)建立一个临床试验小组和细胞治疗生产合作，在两年内通过BMT-CTN和PACT进行随机、多机构试验。 公共卫生相关性：经历脐带血移植的患者通常是少数民族或混合种族背景，由于这些患者经历的白色血细胞（特别是中性粒细胞）恢复的显著延迟，这些患者在移植后感染和早期死亡的风险增加。然而，使用一种新的培养方法，我们首次证明了从单个单位的脐带血中产生更多细胞的能力，这些细胞在临床环境中输注时能够快速恢复中性粒细胞。进一步开发这种产品以确认我们最初的有希望的结果需要额外的临床试验，如果成功，可能会改变脐带血移植的方式。

DESCRIPTION (provided by applicant): With the goal of overcoming the significant delay in neutrophil recovery that occurs following transplantation with umbilical cord blood (CB), we have successfully developed a novel and clinically feasible methodology utilizing an engineered Notch ligand for the ex vivo generation of increased numbers of CD34+ cells. A Phase I clinical trial utilizing Notch-mediated expanded CB progenitors in patients undergoing a myeloablative cord blood transplant (CBT) is currently underway. Results from this trial have not only demonstrated the safety of this approach, but more importantly have for the first time demonstrated that rapid myeloid engraftment can be achieved following infusion of ex vivo expanded hematopoietic progenitors. A significant reduction in median time to an absolute neutrophil count of 500/<ml to just 16 days has been observed in patients receiving expanded cells as compared to a median time of 26 days (p=0.002) in a concurrent cohort of 20 patients undergoing identical treatment but with two non-manipulated CB units. Thus, although the number of patients treated to date is small (n=10), a significant effect on time to myeloid recovery has been clearly demonstrated, as has the safety and clinical feasibility of this approach. Further advancement of this methodology now depends on determination of clinical efficacy, which will require a randomized multi-institutional trial. Prior to initiation of such a trial, several critical issues will need to be addressed, including the ability to manufacture and safely ship cells to outside centers, establishment of an appropriate clinical trials and cell therapy manufacturing collaborative group(s) to conduct a future Phase II randomized multi-institutional trial, and determination of need for HLA-matching of the ex vivo expanded product for clinical use. It is our goal that at the end of the two year funding period, we will be prepared and completely ready to begin critical phase II studies. Specifically, we now propose the following aims: 1) Determine methods for shipping expanded cells to outside centers for infusion, including preclinical evaluation of in vivo repopulating ability in our established murine model of the proposed methods. Following this, we will conduct a 10 patient pilot study as an extension of our current Phase I trial with Dr. John Wagner at the University of Minnesota to evaluate the safety and feasibility of overnight shipment of cells. 2) In a concurrent pilot study to be conducted locally, determine whether infusion of the expanded cell product, which is devoid of T cells, can be infused without need for HLA- matching. In this study, patients undergoing conventional CBT will receive CB progenitors previously expanded from a fresh CB unit and then cryopreserved for future use as an "off-the-shelf" product. If successful, this would dramatically increase patient access to this product. 3) Establish a clinical trials group and cell therapy manufacturing collaborations required to conduct a randomized, multi-institutional trial in two years time via the BMT-CTN and PACT if possible. PUBLIC HEALTH RELEVANCE: Patients undergoing a cord blood transplant, who are often of minority or mixed ethnicity background, are at increased risk of infection and early death following the transplant due to the significant delay in white blood cells recovery (in particular, neutrophils) that these patients experience. However, using a novel culture methodology, we have demonstrated for the first time the ability to generate increased numbers of cells from a single unit of cord blood that are capable of rapid neutrophil recovery when infused in the clinical setting. Further development of this product to confirm our initial promising results requires additional clinical trials that, if successful, could change the way cord blood transplantation is performed.