New substances: risk assessment, New Substances Notification 21561

Name of company: Future Fields

First day of assessment period: July 5, 2023

Last day of assessment period: January 11, 2024 (due to extension of the assessment period)

Identity: A genetically modified Drosophila melanogaster strain with a single insert of a tconstruct containing a gene expressing human FGF2 and a marker gene balanced over a chromosome balancer

Organism type: Insect

Use: Production of human fibroblast growth factor 2 (human FGF2) for use as a supplement for growing cells in vitro for research and development purposes

Anticipated quantity: Approximately 1 100 to 1 400 kg of the notified organism is expected to be manufactured in the first 12 months with an estimated annual maximum of 3 156 kg.

Assessment level of concern:

• Human health hazard: Low
• Human exposure: Low
• Environmental hazard: Low for environmental effects
• Environmental exposure: Low

Assessment conclusion under section 64 of the Canadian Environmental Protection Act, 1999: Not suspected to be toxic.

Recommended action: No further action recommended.

Waiver: Requested under paragraph 106(8)(a) of the Canadian Environmental Protection Act, 1999 for information element 5(a) of Schedule 5 of the New Substances Notification Regulations (Organisms) [the data from a test conducted to determine its pathogenicity, toxicity or invasiveness]

Synopsis

Drosophila melanogaster strain 2 is a genetically modified fruit fly that was notified for use in the production of human fibroblast growth factor 2 (human FGF2).

A waiver to submit data from a test to determine the pathogenicity, toxicity, or invasiveness of the notified strain under Section 5(a) of the New Substances Notification Regulations (Organisms) [NSNR(O)] was accepted by the program under section 106(8)(a) of the Canadian Environmental Protection Act, 1999 (CEPA).

Based on information from literature searches and the evaluation of information submitted by the notifier, the risk assessment concluded that the hazard potential and the exposure potential to human health from the manufacture of the notified organism is low.

Based on information from literature searches and the evaluation of information submitted by the notifier, the risk assessment concluded that the hazard potential and the exposure potential to the environment from the manufacture of the notified organism is low.

This assessment is subject to a scientific expert peer review by the Government of Canada.

Drosophila melanogaster strain 2: background information

As a species, Drosophila melanogaster has an extensive history of safe use in research and development. It is not known to have adverse effects on other species present in the natural environment nor is it known to be a vector for disease. D. melanogaster strain 2 is a line of genetically modified (GM) fruit fly to be used to produce human FGF2. The notified line is derived from a common and commercially available laboratory strain of D. melanogaster and will be manufactured under controlled conditions in a single contained facility in Edmonton, Alberta. The produced recombinant protein will be used as a growth medium supplement in cell culture for research and development only.

Hazard assessment

The environmental hazard potential of D. melanogaster strain 2 is assessed to be low because:

1. D. melanogaster strain 2 is derived from a commonly used laboratory strain which is severely inbred with reduced reproductive and survival fitness and is not expected to propagate in the environment in the event of accidental release
2. As a species, D. melanogaster has an extensive history of safe use in research and development
3. D. melanogaster is not known to have adverse effects on other species present in the natural environment nor is it known to be a vector for disease
4. The genetic material inserted, and the expressed protein human FGF2, are not known to have pathogenic or toxic effects on other species present in the natural environment
5. A waiver for pathogenicity, toxicity, or invasiveness testing was granted under section 106(8)(a) of CEPA for D. melanogaster strain 2 as, after extensive review of the literature and information submitted by the notifier, it was concluded that data on toxicity were not required to determine whether the living organism is toxic or capable of becoming toxic

The human hazard potential of D. melanogaster strain 2 is assessed to be low because:

1. D. melanogaster strain 2 is a GM fruit fly derived from a commonly used laboratory strain which is not known to be associated with any hazards to humans
2. The methods used to produce the notified living organism do not raise any human health concerns. None of the source (donor) organisms from which the inserted genetic material was derived are known to produce toxins, nor is the genetic material or human FGF2 protein associated with any toxicity or pathogenicity in humans
3. While wild D. melanogaster have been reported to harbour opportunistic human pathogens, there are no reported cases of zoonotic infections attributed to the species
4. The expressed human FGF2 protein is not expected to be toxic or allergenic as it is not structurally similar to any known allergens or toxins

Hazards related to organisms used in the workplace should be classified accordingly under the Workplace Hazardous Materials Information System (WHMIS)^{Footnote 1} .

Exposure assessment

The environmental exposure potential of D. melanogaster strain 2 is assessed to be low because:

1. D. melanogaster strain 2 is intended for use as a living insect bioreactor in a contained facility and is not intended for release into the environment. There are no other foreseeable potential uses for the notified strain outside of the intended use, as the genetic modification leads to the expression of a single protein for use in a specific commercial product
2. The containment and operating procedures that the notifier has put in place at the facility are sufficient to ensure containment of the notified organism. The organism has been genetically modified using a balancer chromosome to impart curly wings to reduce the ability to fly, as a biological containment measure. However, approximately 1/3 of the progeny lack the curly wing characteristic and will develop into transgenic straight-winged adults with the ability to fly. The notifier also has measures in place to identify and dispose of the approximate 30% of adult flies with straight wings, which were deemed to be satisfactory. In the very unlikely event that there is an inadvertent release of straight-wing adult flies, environmental conditions for dispersal and mating with wild species of fruit flies are only available for a short window as the flies cannot withstand cold
3. The genetic mutations of the parent strain and modifications to the notified organism result in reduced locomotion and reproductive fitness. In the unlikely event of escape to the environment, the notified organism and its genes are unlikely to propagate in external D. melanogaster populations. Regular checks of the physical characteristics and genetic make-up are done to ensure stocks remain uncontaminated from external or internal sources
4. Protein is harvested only from the larval life stage (which are flightless and have limited mobility), and adult flies representing 1-2% of the total population are used only for strain maintenance and propagation. The notified organism will be euthanized and the expressed human FGF2 protein extracted for use in cell culture media

The human exposure potential of D. melanogaster strain 2 is assessed to be low because:

1. The main source of human exposure to the notified organism is expected to be occupational exposure from the manufacture of D. melanogaster strain 2 in a contained facility located in Edmonton, Alberta
2. D. melanogaster strain 2 is not intended for release into the environment from the facility. Containment measures in place are expected to prevent releases, and larvae will be harvested and euthanized to extract the human FGF2 protein. The general population is therefore not expected to be exposed to live strain 2 flies
3. In the event of an accidental release, dispersal is expected to be limited given that most (~ 70%) adult flies will have curly wings, which reduces the organism’s ability to fly, reproduce, and survive in the wild. The notifier adequately described measures in place to identify and dispose of adult flies with straight wings (~ 30%). It is noted that wild type fruit flies live in close association with humans and benefit from their surroundings and activities, thus the general population are routinely exposed to the species without reported cases of adverse effects. However, in the very unlikely event of an inadvertent release of straight-wing adult flies, environmental conditions may be favourable, although very limited, for both survival and human exposure

Risk characterization

Owing to the low potential hazard and the low potential exposure, the environmental risks associated with the use of D. melanogaster strain 2 for production of human FGF2 is low.

Owing to the low potential hazard and the low potential exposure, the human health risks associated with the use of D. melanogaster strain 2 for production of human FGF2 is low.

Risk assessment conclusion

There is no evidence to suggest a potential risk of adverse environmental effects or propagation in external, wild D. melanogaster populations at the exposure levels predicted in the environment from the use of D. melanogaster strain 2 for production of human FGF2. The risk to the environment associated with D. melanogaster strain 2 is not suspected to meet criteria in paragraphs 64 (a) and (b) of CEPA.

There is no evidence to suggest a potential risk of adverse human health effects at the exposure levels predicted in the environment from the use of D. melanogaster strain 2 for production of human FGF2. The risk to human health associated with D. melanogaster strain 2 is not suspected to meet criteria in paragraph 64 (c) of CEPA. No further action is recommended.