Enclosed by mesh fences and walls sits a lone rice paddy stretching out across 1,100 square meters in Tsukuba, Ibaraki Prefecture.
This isolated space on the grounds of the National Agriculture and Food Research Organization (NARO) yielded a 440-kilogram harvest on Sept. 5. This is far from the end of the project’s journey, but it reflects the tenacity of those involved in its research.
“The rice has grown hardily despite many sweltering days thanks to few insects and pests appearing,” said Yuya Wakasa, 48, a senior researcher at NARO, who is responsible for the produce’s cultivation.
After more than 20 years since research kicked off, a variety of genetically modified rice designed to alleviate cedar pollen symptoms is finally progressing toward clinical application.
The entirety of the September harvest was specifically engineered to combat hay fever associated with Japanese cedar pollen.
Hay fever is caused by allergies brought on by the immune system overreacting to pollen coming into contact with the body.
Researchers genetically manipulated the existing Kitaake rice variety, which served as the base, to produce rice with allergens found in pollen to combat this.
This builds on the idea that instead of causing further distress, regularly consuming rice with a small number of allergens that cause hay fever would reduce sensitivity to it over time and suppress allergy symptoms.
FROM FOOD TO MEDICINE
NARO began developing this new species of rice in 2000. Rice boasting the same cedar pollen-fighting effects as this year’s harvest was successfully released in 2003.
While it was initially supposed to be exclusively distributed as food, attention later shifted to creating medicine from the crop. Interest in exploring the potential of using it in tandem with the immune system to produce positive effects led to a series of experiments on mice.
Research progressed to limited human trials between 2013 and 2018, with NARO working alongside the Jikei University School of Medicine in Tokyo’s Minato Ward. During the clinical studies, participants ate the rice with the aim of determining whether it was truly effective in curbing Japanese cedar pollen allergies.
The survey suggested that consuming the crop might contribute to a reduced frequency of sneezing and a decreased need for medication. An improvement in subjective symptoms was likewise observed, with some reporting they were, “feeling better today,” for example.
GOVERNMENT ROADBLOCKS & SUPPORT
The project was soon placed on hold, however. The agricultural ministry’s reasoning was that utilizing allergens in immunotherapy for hay fever was not common at the time.
“No genetically manipulated farm products had been taken advantage of as drug ingredients before,” recalled Tadashi Furusawa, 59, head of NARO’s crop genome editing research division.
Referencing another problem, Furusawa added that the clinical study “targeted only a small group of people” and thus “failed to make clear the rice’s therapeutic potential.”
The project stalled, but a turning point finally appeared in May 2023—a new clinical study under the agriculture ministry’s jurisdiction for commercializing cedar pollen-infused rice was approved.
The decision was made during a meeting of relevant ministers about hay fever, and a joint public-private task force was set up within the ministry.
The task force’s midterm report, released in June this year, proposed extracting an active component of the cedar pollen-infused rice. The chemical is anticipated to be used in powder in further experiments to develop what would be a radical cure for hay fever.
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Most conventional drugs for cedar pollen allergies are simply intended to ease symptoms.
For now, patients seeking radical therapy to eliminate their allergies have no choice but to take specialized tablets or drops for sublingual immunotherapy where patients are directly exposed to what they are allergic to.
Subcutaneous injections where allergens are administered as shots between a patient’s muscle and fat layers is another method.
These options are made with uninhibited Japanese cedar pollen allergens and severe allergic reactions are among the treatments’ side effects.
Conversely, immunotherapy using the cedar pollen-infused rice would ideally suppress such alarming effects since a much smaller portion of the actual allergen found in the plant is involved.
“The immunotherapy agent featuring the cedar pollen rice variant may effectively relieve hay fever symptoms without causing adverse side effects,” said Tomonori Endo, 48, a doctor who heads Tokyo Kyosai Hospital’s otolaryngological department.
Endo was also previously involved in the past clinical survey for the rice at the Jikei University School of Medicine.
His expectations are high. “With potentially long-lasting effects, this medicine could represent an unprecedented, next-generation treatment,” Endo said.
At the same time, he stressed that incorporating different genes into rice might make it possible to use the food staple to help with other allergies as well.
LONG WAY TO GO
With research back under way, several major challenges remain.
The envisioned clinical study must evaluate the effectiveness and safety of the rice-derived medicine’s effectiveness on a substantial number of subjects. This would involve administering the medicine for two to three years.
Additionally, the study must confirm whether positive effects persist beyond the end of administering the medicine.
Another problem involves the stable supply of the rice to serve as the key ingredient for the planned medicine.
To address this issue, a plan is being considered to forge ahead with research to cultivate the modified rice at a dedicated indoor farm. The purpose is not only to make it possible to harvest it several times a year, but also mitigate quality variations—differences in yield and concentration of the necessary ingredient are among them.
Given the range of difficulties, Endo foresees a long road ahead before the revolutionary medicine is ready for public use.
“An additional five to 10 years will likely be required,” he said.
