Clinical trial with Meclozine for achondroplasia

Professor Hiroshi Kitoh and his research team from the Graduate School of Medicine

at Nagoya University, Japan, will advance with clinical studies on meclozine, an over-the-counter drug for motion sickness and vertigo, which they observed to promote bone growth in mice model with achondroplasia, (1) back to 2013, after using a comprehensive screening of FDA-approved drugs. Kitoh and his team identified that meclozine inhibited FGFR3 signaling in chondrocytes (achondroplasia is caused by gain-of-function mutations in the fibroblast growth factor receptor 3 (FGFR3) gene). Additionally, the team observed that meclozine promoted longitudinal bone growth in transgenic mice with achondroplasia. (2)

Figure 1. Meclozine significantly increased longitudinal bone length in mice with achondroplasia phenotype. Credits: Nagoya University, Orthopedics Laboratories (2)


Meclozine as a repurposing drug for achondroplasia: Clinical trial and timelines


After several years after the first publication on meclozine as a possible repurposing drug for achondroplasia: "Meclozine Facilitates Proliferation and Differentiation of Chondrocytes by Attenuating Abnormally Activated FGFR3 Signaling in Achondroplasia", a clinical trial on meclozine for achondroplasia is anticipated to start on the 30th July 2018, with 6 children with achondroplasias, from 5 to 11 years old. The study will be conducted in Nagoya University Hospital, Japan. (4)


Figure 2. Hiroshi Kitoh, Pediatric Orthopedic surgeon and Associate Professor at Nagoya University. Credits: Nagoya University (3)


The objective of Phase 1 clinical trial with Meclozine

Kitoh and his team will now investigate the optimal dose of meclozine for the treatment of short stature in achondroplasia for further clinical feasibilities. (2) This Phase 1 will allow evaluating safety as well as 24-hour pharmacokinetics and accumulation at 1 week in children bodies after a single dose of meclizine of 25mg/day. All information available can be read in full on the official site UMIN-CTR Clinical Trial. (4) The next step will be to run a second study, with other 6 children, that will receive the double of the dose of meclozine. This study is predicted to occur in late 2018.

The advantage of repurposing drugs for Rare diseases

Drug repurposing has real promise for rare genetic conditions. There are over 7000 different rare diseases and, with rapid advances in the knowledge of the human genome, the number is constantly expanding. Repurposing helps to speed the identification of viable opportunities for a condition, it can also act to lower the need for early-stage clinical trials which test drug absorption and tolerability in humans. Removing such steps in the clinical pathway helps to reduce the time drugs take to reach the clinic and spend on clinical development. This has the potential to lower development costs, which one would hope could lower the price of the drug on the market. (6)


Figure 3. Major steps and estimated time involved in the conventional drug development process. The estimated time of drug development can be significantly reduced by repurposing old drugs. Credits: Gupta et al, 2013 (5)


Nevertheless, there are still several studies needed to be conducted, and at this stage, evaluating safety of the administration of meclozine in children is now key.



  3. Orthopedics Department, Nagoya University
  4. UMIN-CTR clinical trial
  5. Gupta S et al., Cancer drug discovery by repurposing: teaching new tricks to old dogs" Volume 34, Issue 9, p508–517, September 2013
  6. News Medical, Life Sciences, "Teaching old drugs new tricks - drugs repurposing for rare diseases"