Medical progress this week
Top 5 advances: 12th to 18th May
Every week I make a list of (what I find to be) the five most potentially impactful medical advances.
Here’s this week’s:
The first ever bespoke CRISPR therapy
Tirzepatide beats semaglutide for weight loss
A medication to treat the migraine prodrome
An emerging way to lower lipids
Early stages of a vaccine for HIV
1. The first ever bespoke CRISPR therapy
This might be the fastest a medicine’s ever been produced: from scratch to the patient in 6 months.
It’s for an ultra-rare genetic condition (carbamoyl-phosphate synthetase 1 deficiency) which causes accumulation of toxic ammonia and usually causes death in childhood.
It’s a bespoke CRISPR therapy, tailored for one patient’s mutation - it was tested in a lab first, then mice, non-human primates, and dosed into a patient via lipid nanoparticles.
How this looks in the long-term isn’t yet known, but the patient is currently 8 months of age and thriving. This approach could - in theory - be applied to hundreds of other rare genetic illnesses.
Source: Musunuru et al., NEJM 2025
2. Tirzepatide beats semaglutide for weight loss
Tirzepatide (Zepbound) is a GLP1 receptor agonist like semaglutide (Wegovy), but tirzepatide is a dual agonist: it also activates the GIP receptor, which means less hunger, more insulin sensitivity, and more fat loss.
People taking tirzepatide usually lose more weight than those taking semaglutide, but they’ve never been tested head-to-head, both at the maximally-tolerated dose, in patients without type 2 diabetes.
This phase 3 trial shows that tirzepatide is more effective for weight loss.
Side-effects were similar between the two - some (vomiting, acid reflux) were less frequent with tirzepatide while others (injection-site reactions) were more common.
Source: Aronne et al., NEJM 2025
Eli Lilly
3. A medication to treat the migraine prodrome
Migraine progresses through stages - prodrome (light/sound sensitivity, fatigue), aura, headache, and postdrome. It’s thought that migraine starts when pain-sensing fibres in the trigeminal nerve get activated, releasing the neuropeptide, CGRP, which amplifies the signal and makes the headache worse.
CGRP blockers can prevent migraine (when taken continuously, in the absence of symptoms) and can also treat the headache after it starts, but this phase 3 trial shows that an oral CGRP blocker - ubrogepant - can also reduce prodrome symptoms if taken on-demand.
This will only be useful to those who are able predict when their migraine is coming, but this is the first medication ever proven to do this.
Source: Goadsby et al., Nature Medicine 2025
AbbVie
4. A new way to lower lipids
About 2% of the population have loss-of-function genetic mutations that means they have lower triglycerides, lower remnant cholesterol, lower type 2 diabetes risk and a lower cardiovascular risk - without apparent negative health effects.
The mutation is in ANGPTL4, which is produced by adipocytes (fat cells) - this protein inhibits an enzyme called lipoprotein lipase, so if ANGPTL4 isn’t active, lipoprotein lipase is more active, and there’s more breakdown of triglycerides.
Building on this idea, this is a phase 1b/2a trial, which finds that an ANPTL4-inhibiting antibody can reduce triglycerides and (because of this) remnant cholesterol.
These are early data, and there’s no evidence yet that this reduces cardiovascular risk - but it joins other emerging lipid-lowering therapies built on genetic evidence.
Source: Cummings et al., The Lancet 2025
Marea Therapeutics
5. Early stages of a vaccine for HIV
The HIV field has been recently revolutionised by long-acting anti-retrovirals (like Lenacapavir), which are extremely effective to prevent HIV (approval decision expected in June...). But if we had a vaccine, too, we could really make progress toward controlling HIV around the world.
These are early (phase 1) data for an HIV vaccine.
Tested in healthy humans, and coupled with an adjuvant (that stimulates the immune response) the vaccine elicits antibodies that target HIV’s binding to T cells. How effective this is to prevent HIV in humans isn’t yet known.
This joins a second early HIV vaccine also reporting results this week - showing the momentum in this area.
Source: Caniels et al., Science 2025