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Science Policy Around the Web – February 26, 2019

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By: Jennifer Patterson-West, Ph.D.

Source: Ellsworth Airforce Base

Scientists Release Controversial Genetically Modified Mosquitoes In High-Security Lab

Malaria is a parasitic disease that affects more than 200 million people each year.  Symptoms can range from mild to severe, and include high fever, chills, and flu-like symptoms.  These symptoms are more dangerous to children under the age of 5, which account for 77% of related deaths.

The life cycle of malaria requires two hosts: humans and female Anopheles mosquitoes.  It is important to note that not all species of Anopheles mosquitoes are good vectors, in fact, only 30-40 of the approximately 430 species transmit malaria in nature. The life cycle of malaria is also dependent on additional environmental factors including ambient temperature and humidity. Together these factors account for the geographic distribution of malaria. Although malaria is found more than 100 countries, transmission is most prevalent in Sub-Saharan Africa and in parts of Oceania including Papua New Guinea. 

In the past decade, major gains have been made to control the disease in developing nations thanks to increased funding. Current preventative measures include insecticide-treated netsindoor residual spraying, and intermittent preventative treatment for individuals at increased risk including pregnant women and infants.

In early February, a high-security laboratory in Terni, Italy launched a study to evaluate a new powerful weapon against the mosquito vector.  This new weapon is a genetically modified mosquitothat can spread a genetic mutation lethal to its own species. Researchers targeted the gene “doublesex” to producing female mosquitos that are sterile and have mouths resembling male mosquitos, which are unable to bite.  

The goal is to dramatically crash or reduce the local population of the main species of malaria spreading mosquitoes, Anopheles gambiae. To increase heritability of the mutation, researchers utilized CRISPR technology to engineer a “gene drive” into the genetically modified species. Gene drive inheritance ensures that nearly all progeny inherits the mutation.

Despite the need for new methods for reducing malaria, activists and other scientists warn that the technology can have unforeseen effects on the environment.  The environmental group, Friends of the Earth, is part of international coalition protesting the use of these new genetically modified organisms. Jim Thomas of the ETC group, has noted concern that gene drive technologies can also be used to develop biological weapons.  

To reduce the risk associated with releasing the gene-drive mosquitoes, the project plans years of additional study that will methodically and cautiously evaluate the mosquitoes and their potential environmental impacts with close consultation from other scientists, government officials, and local residents in Africa.

(Rob Stein, NPR)

With one manufacturer and little money to be made, supplies of a critical cancer drug are dwindling

Bacillus Calmette-Guerin (BCG) is a potent immunotherapy for the treatment of fast-growing bladder cancer.  BCG was initially used in 1921 as a tuberculosis vaccine.  In the 1970s, BCG was shown to stimulate the immune system to attack tumor cells when administered through a catheter into the bladder of cancer patients. Since then, BCG has become a potent treatment for intermediate and high-risk non-muscle invasive (NMI) urothelial cancer (UC) of the bladder.

Bladder cancer is the nation’s sixth most prevalent cancer with approximately 80,000 new cases each year.  About 20% of these patients are diagnosed with a type of bladder cancer that can be treated with BCG.  Although BCG doesn’t work for all eligible patients, the response rate is more than 70%.

Despite the established potency of BCG, there is a critical national shortage.  Supplies of BCG have been erratic since 2011, when the United States Food and Drug Administration (FDA) promptly shut down the Sanofi manufacturing lab after a failed inspection.  After continued regulatory issues, Sanofi stopped production of BCG in 2016. Merck is now the only manufacturer of BCG for the Unite States and European markets.

Merck has acknowledged short supplies and indicated that they are currently working at capacity.  Tyrone Brewer, the vice president of global oncology marketing at Merck, has indicated that the company intends to continue producing BCG for “the foreseeable future.”

During shortages, chemotherapies, such as mitomycin, can be used as alternative therapies.  However, they have lower efficacy and a higher price tag than BCG. During the 2014 BCG shortage, the cost of mitomycin increased by 99% further exacerbating the financial burden of these alternative therapies. 

In response to erratic supply of BCG, the Southwest Oncology Group has launched a clinical trial (S1602) to compare the TICE BCG strain currently used in the United States to the Tokyo Strain.  The FDA will consider the results of this trial as critical information for approving the Tokyo strain for use in the United States. 

In the meantime, urologists have begun to divide dosages into thirds to prolong supplies.  However, a recent literature review indicated that a large scale, well-designed, prospective study is need to establish a standard dose and maintenance instillation for reducing recurrence rate since the efficacy of lower dosage is unclear from existing data.

The University of Utah Drug information Service reported that in 2015 approximately 265 generic drugs were in short supply in the United States.  Of potentially greater concern than the current shortage of BCG are generic drugs that can have immediate life and death consequences. For instance, a retrospective study of the norepinephrine shortage in 2011 indicated a 10% higher mortality rate during hospitalization when the alternative vasopressor, phenylephrine was used.

A recent perspective from Davies et al. argues that current policy efforts have not sufficiently prevented supply disruptions of important generic drugs.  A major consideration for dealing with generic drug shortages are the unintended consequences of current policies. For instance, the 2003 Medicare Modernization Act, which sought to protect consumers by limiting the cost increase for generic drugs to 6% above the Medicare average sale price (ASP). This restriction may not provide manufactures with sufficient proficient to invest in production facilities.  

Further compounded these issues is the fact that manufacturers face few negative consequences during shortages, whereas an excess in supply cuts in to profit margins. To provide additional incentive for maintaining reliable supplies of generic-drugs, Davies et al. suggested that the FDA prioritize the review of future generic-drug applications from companies that “maintain generic drug production without quality-control problems”.  In November, the FDA issued a news release about efforts to address drug shortages, which included remedying the underlying problems when a shortage arise within their current authorities.  In today’s political climate, any policy reform or expanse to FDA’s authority to mitigate future shortages and provide incentives for the production of generic medications will require cross-party support. 

(Meghana Keshavan, STAT news)

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Written by sciencepolicyforall

February 26, 2019 at 1:44 pm