By: Tanvi Ambekar

Opinion Editor

In the flurry of current international scientific developments, two separate companies in Japan have recently announced the approval of two new stem cell therapies thought to be effective treatments for severe heart failure and Parkinson’s Disease

Both therapies rely on the manipulation of induced pluripotent stem cells (iPS cells), a diverse subset of cells capable of differentiating into any cell in the human body. Naturally, these cells are found only in blastocysts, embryos formed five to seven days after fertilization. The outer layer develops into the placenta while the inner layer, composed almost entirely of pluripotent stem cells, becomes the baby. 

Two decades ago, harvesting pluripotent stem cells from a blastocyst would have required killing the embryo. However, in 2006, Professor Shinya Yamanaka of Kyoto University in Japan was the first to create mouse iPS cells. He shared the Nobel Prize in 2012 for his work with fellow scientist John B. Gurdon, and rightfully so; their work opened a new field of stem cell research focused on iPS cells. 

Now, Professor Yamanaka’s work has seen its first real progression towards applicable therapies. Cuorips, an Osaka-born startup, received legal approval for its heart muscle sheets on Mar. 6. 2026. The treatment, branded as ReHeart, works by replacing dysfunctional heart tissue with new cells. Unlike existing treatments, ReHeart serves as a near-permanent solution for severe heart failure, providing a more effective way to treat once fatal conditions.

The other product, dubbed Amchepry, uses iPS cell-derived brain cells that differentiate into dopamine-producing nerve cells. Late-stage Parkinson’s Disease is partially caused by neurons in the brain being unable to synthesize, transmit, and sense dopamine, an important neurotransmitter. Amchepry, developed by Sumitomo Pharma, replaces the faulty cells with functional ones to reduce Parkinson’s symptoms. Similar to ReHeart, scientists hope that Amchepry can become an effective remedy for the currently untreatable Parkinson’s Disease. 

Of course, any new treatment must be handled carefully. So far, ReHeart has only been tested on eight heart failure patients, all of whom showed symptomatic improvements. Amchepry testing on six patients showed improvement in four, including a reduction in tremors, the main effect of the neurodegeneration in Parkinson’s Disease. However, researchers remain hopeful that, with further testing and iteration, both treatments will take significant steps toward Parkinson’s and heart failure solutions.

The creation and publicization of both ReHeart and Amchepry are a testament to the importance of the constant pursuit of scientific knowledge. The passion of scientists like Shinya Yamanaka, John B. Gurdon, and others, is what drives medicine and humanity forward.

(Sources: BioInformant, Nature, Nikkei Asia, ScienceDirect, The Japan Times)