Here are some of the biggest medical advances in 2023

New treatments include the first CRISPR gene-editing therapy, an Alzheimer’s drug and RSV vaccines

A photo illustration of a package of Narcan

In March, the U.S. Food and Drug Administration said the nasal spray Narcan, which can reverse the effects of an opioid overdose, could be sold over the counter.

Justin Sullivan/Getty Images News

Weight-loss drugs stole much of the spotlight in 2023, but these medical advances treating other conditions are also worthy of attention (SN: 12/13/23).

Green light for CRISPR gene editing

On December 8, the U.S. Food and Drug Administration approved the world’s first CRISPR/Cas9 gene-editing therapy (SN: 12/8/23). The treatment, called Casgevy, targets sickle cell disease by helping patients produce healthy hemoglobin. In people with the disease, hemoglobin is abnormal, causing red blood cells to become hard and crescent shaped, which can block blood flow. By March 2024, the FDA will decide whether the same therapy can be used to treat beta-thalassemia, a disorder that reduces hemoglobin production.

Slowing down Alzheimer’s

The Alzheimer’s drug lecanemab (brand name Leqembi) won full FDA approval in July. Like the drug aducanumab approved in 2021, lecanemab removes the amyloid plaques that build up in the brains of people with Alzheimer’s. The drug doesn’t stop the disease, but in a clinical trial, lecanemab slowed cognitive decline by about 30 percent over 18 months compared with a placebo (SN: 8/12/23, p. 9).

A gene therapy for muscular dystrophy

In June, the FDA approved the first gene therapy for children with Duchenne muscular dystrophy. Due to a faulty gene, people with this muscle-wasting disease don’t make the protein dystrophin, which helps keep muscle cells intact. The therapy helps the body produce a version of the missing protein (SN: 6/22/23).

Guarding against RSV

Several ways to protect against respiratory syncytial virus arrived this year. In May, the FDA approved the first RSV vaccine, called Arexvy, in the United States, for adults age 60 and older (SN: 6/17/23, p. 8), and then in August, a vaccine for pregnant people, called Abrysvo (SN: 8/25/23). A monoclonal antibody — a lab-made antibody that mimics immune system proteins — won approval in July to protect children 2 and younger from the virus, which sends as many as 80,000 young children to U.S. hospitals each year (SN: 4/27/23). But in October, limited supplies of the therapy led the U.S. Centers for Disease Control and Prevention to recommend reserving it for babies at highest risk for complications from RSV.

A pill for postpartum depression

Until August, the only medication in the United States specifically targeting postpartum depression required a 60-hour intravenous infusion in a hospital (SN: 3/22/19). With FDA approval of zuranolone (brand name Zurzuvae), those afflicted with postpartum depression can take an oral medication at home and experience improvement in as little as three days.

Birth control, no prescription required

In July, the FDA ruled that the oral contraceptive norgestrel, first approved in 1973, be available without a prescription. It’s the first OTC daily birth control pill in the United States. Some public health experts argue that reducing barriers to contraception is especially important to reproductive autonomy now that state bans have limited access to abortion (SN: 5/19/23).

A shot against chikungunya

The chikungunya virus can cause fever and severe joint pain, and be fatal to newborns. In November, the FDA approved the first vaccine against the virus, which is transmitted by mosquitoes. The virus is most prevalent in tropical regions, but the FDA warns that it’s spreading to new parts of the globe.

Narcan over the counter

The nasal spray Narcan, aka naloxone, can reverse the effects of an opioid overdose within minutes. In March, the FDA ruled this life-saving drug can be sold over the counter. Officials hope that easier access to Narcan can help fight the opioid epidemic, which claimed the lives of nearly 645,000 people from 1999 to 2021 due to overdoses.

Erin Wayman is the managing editor for print and longform content at Science News. She has a master’s degree in biological anthropology from the University of California, Davis and a master’s degree in science writing from Johns Hopkins University.