Japan is moving to commercialize two groundbreaking stem cell therapies — one for Parkinson’s disease and another for severe heart failure — in what experts are calling a historic milestone in regenerative medicine.

Earlier this month, a Japanese government panel approved the world’s first commercialization of treatments derived from induced pluripotent stem cells (iPS cells) for these conditions.

These adult cells have been reprogrammed into an early developmental state, allowing them to transform into nearly any type of cell in the body. The discovery earned Kyoto University scientist Shinya Yamanaka the Nobel Prize in Physiology or Medicine in 2012.

Parkinson’s Therapy

The Parkinson’s treatment, called Amchepry, was developed by Kyoto University and Sumitomo Pharma. The therapy uses dopamine-producing neurons created from donated iPS cells. These cells are transplanted into the brain to help restore dopamine levels, which are depleted in people with Parkinson’s disease.

In an early trial, seven patients received the transplants. Four showed improvement in their symptoms. Phase I/II trials designed to assess safety reported no serious side effects.

Heart Failure Therapy

The second treatment, ReHeart, was developed by Cuorips, a Tokyo-based regenerative medicine company spun out of Osaka University research.

The therapy uses heart muscle (myocardial) cells derived from donated iPS cells. Scientists engineered the cells into small, coin-shaped patches that are surgically placed on the surface of the heart. The goal is to improve heart function in patients with severe heart failure caused by ischemic cardiomyopathy.

Researchers say the patches may help stimulate new blood vessel growth and repair damaged heart tissue. The therapy has been tested in eight patients so far. Early findings suggest it appears safe and may help some recipients increase their physical activity levels.

Concerns About Limited Data

According to Nature, critics argue that the clinical data supporting both therapies remain limited. The trials have involved small numbers of participants and lacked control groups — considered the gold standard for determining a treatment’s true effectiveness and risk.

Despite these concerns, Japan’s health ministry has recommended that both therapies receive “conditional and time-limited approval.” Under this designation, the treatments can be marketed to a limited number of patients for up to seven years.

During that period, developers will continue gathering safety and efficacy data while working with insurers and healthcare providers to determine pricing.

If successful, the therapies could pave the way for a new era in stem cell–based treatments — though researchers say careful monitoring and larger trials will be critical in the years ahead.