Quality and Safety Requirements for Sustainable Phage Therapy Products
可持续噬菌体疗法产品的质量和安全要求
Abstract 摘要
The worldwide antibiotic crisis has led to a renewed interest in phage therapy. Since time immemorial phages control bacterial populations on Earth. Potent lytic phages against bacterial pathogens can be isolated from the environment or selected from a collection in a matter of days. In addition, phages have the capacity to rapidly overcome bacterial resistances, which will inevitably emerge. To maximally exploit these advantage phages have over conventional drugs such as antibiotics, it is important that sustainable phage products are not submitted to the conventional long medicinal product development and licensing pathway. There is a need for an adapted framework, including realistic production and quality and safety requirements, that allowsa timely supplying of phage therapy products for ‘personalized therapy’ or for public health or medical emergencies. This paper enumerates all phage therapy product related quality and safety risks known to the authors, as well as the tests that can be performed to minimize these risks, only to the extent needed to protect the patients and to allow and advance responsible phage therapy and research.
全球范围内的抗生素危机重新激发了人们对噬菌体疗法的兴趣。自古以来，噬菌体就控制着地球上的细菌种群。针对细菌病原体的强效溶菌噬菌体可在数天内从环境中分离出来，或从收集的细菌中筛选出来。此外，噬菌体有能力迅速克服细菌的抗药性，而这种抗药性是不可避免地会出现的。为了最大限度地利用噬菌体相对于抗生素等传统药物的这些优势，重要的是，可持续的噬菌体产品不能采用传统的漫长的医药产品开发和许可途径。有必要建立一个适应性框架，包括现实的生产、质量和安全要求，以便及时提供噬菌体治疗产品，用于 “个性化治疗 “或公共卫生或医疗紧急情况。本文列举了作者已知的所有与噬菌体疗法产品相关的质量和安全风险，以及为最大限度地降低这些风险而可以进行的测试，这些测试仅在保护患者、允许并推进负责任的噬菌体疗法和研究的必要范围内进行。
Antimicrobial resistance in bacteria is an increasingly serious threat in every part of the world [1]. Without action, the world could be heading towards a post-antibiotic era in which common infections become fatal and currently routine surgeries become impossible. New initiatives to tackle the problem of antibiotic resistance are urgently needed.
细菌的抗菌药耐药性在世界各地都是一个日益严重的威胁[1]。如果不采取行动，世界可能会走向一个后抗生素时代，在这个时代，普通感染会致命，目前的常规手术也无法进行。解决抗生素耐药性问题迫切需要新的举措。
One promising solution is the therapeutic use of bacteriophages – the viruses of bacteria, also known as phages – to treat bacterial infections. When discovered in the early twentieth century, phages were immediately applied in medicine (phage therapy) with variable success. After World War II, Western industry and policymakers preferred antibiotics, which at the time had obvious advantages in terms of breadth of coverage and ease of production and patentability, and phage therapy was pushed into the background. Today, phage therapy is again put forward as a potential way to address the current antibiotic crisis [2, 3].
一个很有前景的解决方案是利用噬菌体（细菌的病毒，又称噬菌体）治疗细菌感染。噬菌体在二十世纪初被发现后，立即被应用于医学（噬菌体疗法），并取得了不同程度的成功。第二次世界大战后，西方工业界和决策者更青睐抗生素，因为抗生素在当时具有覆盖面广、易于生产和申请专利等明显优势，而噬菌体疗法则被推到了幕后。如今，噬菌体疗法再次被认为是解决当前抗生素危机的一种潜在方法[2, 3]。
Since time immemorial, phages have controlled bacterial populations on our planet, locked in an evolutionary arms race with their hosts (consisting of the repeated emergence of new phage infectivity and bacterial defense mutations). The capacity of bacteriophages to rapidly overcome bacterial resistance makes them suitable for flexible therapeutic applications. To maximally exploit this key advantage of phages over conventional ‘static’ drugs such as traditional small molecule-type antibiotics, it is important that sustainable phage products are not submitted to the conventional long medicinal product development and licensing pathway [4]. A key goal for the modern phage therapy community must be the development and validation of an expedited product development and licensing pathway in consultation with policymakers and competent authorities.
自古以来，噬菌体就控制着地球上的细菌种群，与其宿主进行着进化军备竞赛（包括反复出现新的噬菌体感染性和细菌防御突变）。噬菌体能够迅速克服细菌的抗药性，因此适合灵活的治疗应用。与传统的 “静态 “药物（如传统的小分子抗生素）相比，要最大限度地利用噬菌体的这一关键优势，重要的是可持续的噬菌体产品不需要经过传统的漫长的医药产品开发和许可途径[ 4]。现代噬菌体疗法界的一个关键目标必须是与政策制定者和主管当局协商，开发和验证一种快速的产品开发和许可途径。
Georgian and Polish phage therapy centers maintain extensive therapeutic phage collections, which are regularly enriched with new phages, thus widening the total host range of the collection and adapting the collection to changing bacterial populations (with regard to host range and antibiotic resistance as well as phage resistance). Moreover, the effectiveness of phages can be readily improved by in vitro selection of (natural) phage mutants that exhibit an increased infectivity range. For example, it is possible to obtain potent lytic phages against problematic enteroaggregative Escherichia coli strains by isolation of new phages from the environment or by selection and adaptation of phages from an existing collection, and this often in a matter of days [5]. As such, phages could probably have been used to help control the O104:H4 (hybrid EAggEC STEC/VTEC pathotype) E. coli outbreak that caused the death of more than 50 patients in Germany in 2011. Unfortunately, authorized use of phages would not have been possible in this otherwise feasible context because under the existing medicinal product legislation such an anti-O104:H4 phage preparation would have taken years to develop, produce and register. Since phages are species and often even strain-specific, it is very likely that current O104:H4‑specific phage preparations will not be effective against future epidemic enteroaggregative E. coli strains. ‘Broad‑spectrum’ phage cocktails active against bacteria that are likely to cause problems in the future could be developed in advance and used as a first line treatment for acute healthcare problems (e.g., foodborne disease outbreaks and bacterial bioweapon threats). However, we need to keep in mind that some of these cocktails will not always work due to the greater biodiversity outside of the laboratory and the existing resistance to specific phages. The cocktails that initially work will need to be regularly updated (e.g., supplemented with new phages in response to the evolution of phage resistance and the involvement of new circulating bacterial strains). There are indications that bacterial resistance to phages, even to cocktails containing multiple potent phages, will inevitably occur [6].
格鲁吉亚和波兰的噬菌体治疗中心拥有大量治疗用噬菌体藏品，这些藏品会定期添加新的噬菌体，从而扩大藏品的总宿主范围，并使藏品适应不断变化的细菌种群（在宿主范围、抗生素耐药性以及噬菌体耐药性方面）。此外，噬菌体的有效性可以通过体外选择（天然）噬菌体突变体来提高，这些突变体表现出更大的感染范围。例如，通过从环境中分离出新的噬菌体，或从现有的噬菌体中进行选择和改造，就有可能获得针对有问题的肠道聚集性大肠杆菌菌株的强效溶解性噬菌体，而这往往只需要几天的时间[ 5]。因此，噬菌体很可能已被用于帮助控制 2011 年在德国造成 50 多名患者死亡的 O104:H4（混合 EAggEC STEC/VTEC 病理型）大肠杆菌疫情。遗憾的是，在这种原本可行的情况下，噬菌体的授权使用是不可能的，因为根据现有的医药产品法规，这种抗 O104:H4 噬菌体制剂的开发、生产和注册需要数年时间。由于噬菌体具有物种特异性，甚至往往具有菌株特异性，因此目前的 O104:H4 特异性噬菌体制剂很可能无法有效对抗未来流行的肠道聚集性大肠杆菌菌株。可以提前开发对未来可能造成问题的细菌具有活性的 “广谱 “噬菌体鸡尾酒，并将其作为治疗急性医疗保健问题（如食源性疾病爆发和细菌性生物武器威胁）的一线疗法。不过，我们需要记住，由于实验室外的生物多样性更多，以及对特定噬菌体的现有抗药性，这些鸡尾酒中的一些并不总是有效。最初有效的鸡尾酒需要定期更新（例如，根据噬菌体抗药性的演变和新的循环细菌菌株的参与，补充新的噬菌体）。有迹象表明，细菌对噬菌体的抗药性，甚至对含有多种强效噬菌体的鸡尾酒的抗药性，将不可避免地出现[ 6]。
Notwithstanding the Intellectual Property (IP) and regulatory hurdles, as well as the empirical evidence suggesting that stable and widely distributed phage preparations (prêt-à-porter) will need to be constantly updated, a few companies have picked up the gauntlet and are slowly moving along the elaborate and expensive conventional medicinal product licensing pathway. The development and marketing of phage medicinal products in the EU – including Good Manufacturing Practice (GMP) production, preclinical and Phase I, II and III clinical trials and centralized marketing authorization – is in fact technically possible (and indeed advisable for some products), providing some minor modifications and logical exemptions are made.
尽管存在知识产权（IP）和监管方面的障碍，而且经验证据表明，稳定和广泛分布的噬菌体制剂（prêt-à-porter）需要不断更新，但仍有一些公司挑起了大梁，正沿着复杂而昂贵的传统医药产品许可途径缓慢前进。事实上，在欧盟开发和销售噬菌体药物产品–包括药品生产质量管理规范 (GMP) 生产、临床前和 I、II、III 期临床试验以及集中销售授权–在技术上是可行的（对某些产品来说也是可取的），但前提是必须进行一些小的修改和合理的豁免。