Gene therapy and blood stem cells cure sickle cell disease patients

Sickle-shaped blood cells. The cells become lodged in blood vessels, causing strokes or excruciating pain as blood stops flowing. Photo courtesy of Omikron/Science Source

Blood is the lifeline of the body. The continuous, unimpeded circulation of blood maintains oxygen flow throughout the body and enables us to carry out our everyday activities. Unfortunately, there are individuals whose own bodies are in a constant battle that prevents this from occurring seamlessly. They have something known as sickle cell disease (SCD), an inherited condition caused by a mutation in a single gene. Rather than producing normal, circular red blood cells, their bodies produce sickle shaped cells (hence the name) that can become lodged in blood vessels, preventing blood flow. The lack of blood flow can cause agonizing pain, known as crises, as well as strokes. Chronic crises can cause organ damage, which can eventually lead to organ failure. Additionally, since the misshapen cells don’t survive long in the body, people with SCD have a greater risk of being severely anemic and are more prone to infections. Monthly blood transfusions are often needed to help temporarily alleviate symptoms. Due to the debilitating nature of SCD, important aspects of everyday life such as employment and health insurance can be extremely challenging to find and maintain.

An estimated 100,000 people in the United States are living with SCD. Around the world, about 300,000 infants are born with the condition each year, a statistic that will increase to 400,000 by 2050 according to one study. Many people with SCD do not live past the age of 50. It is most prevalent in individuals with sub-Saharan African descent followed by people of Hispanic descent. Experts have stated that advances in treatment have been limited in part because SCD is concentrated in poorer minority communities.

Despite these grim statistics and prognosis, there is hope.

The New York Times and Boston Herald recently released featured articles that tell the personal stories of patients enrolled in a clinical trial conducted by bluebird bio. The trial uses gene therapy in combination with hematopoietic (blood) stem cells (HSCs) to give rise to normal red blood cells in SCD patients.

Here are the stories of these patients. To read the full New York Times article, click here. For the Boston Herald article, click here.

Brothers, Emmanuel “Manny” 21 and Aiden Johnson 7 at their home in Brockton, Massachusetts. Both brothers were born with sickle cell disease. Photo courtesy of Matt Stone for MediaNews Group/Boston Herald

Emmanuel “Manny” Johnson was the very first patient in the SCD trial. He was motivated to participate in the trial not just for himself but for his younger brother Aiden Johnson, who was also born with SCD. Manny has a tattoo with Aiden’s name written inside a red sickle cell awareness ribbon.

In the article Manny is quoted as saying “It’s not only that we share the same blood disease, it’s like I have to do better for him.”

Since receiving the treatment, Manny’s SCD symptoms have disappeared.

Brandon Williams received the stem cell gene therapy to replace sickle cells with healthy red blood cells. The tattoo on his right forearm is in honor of his sister, Britney, who died of sickle cell disease. Photo courtesy of Alyssa Schukar for The New York Times

For Brandon Williams of Chicago, the story of SCD is a very personal one. At just 21 years old, Brandon had suffered four strokes by the time he turned 18. His older sister, Britney Williams, died of sickle cell disease at the age of 22. Brandon was devastated and felt that his own life could end at any moment. He was then told about the SCD trial and decided to enroll. Following the treatment, his symptoms have vanished along with the pain and fear inflicted by the disease.

Carmen Duncan participated in the stem cell gene therapy trial and no longer has sickle-cell symptoms. She wants to join the military, something that wasn’t an option until now. Photo courtesy of Sean Rayford for The New York Times

The NY Times piece also profiles Carmen Duncan, a 20 year old from Charleston, South Carolina. She had her spleen removed when she was just two years old as a result of complications form SCD. Duncan spent a large portion of her childhood in hospitals, coping with the pain in her arms and legs from blocked blood vessels. She enrolled in the SCD trial as well and she no longer has any signs of SCD. Duncan had aspirations to join the military but was unable to because of her condition. Now that she is symptom free, she plans to enlist.

This SCD clinical trial has multiple trial sites across the US, one which is the UCSF Alpha Stem Cell Clinic , a CIRM funded clinic specializing in the delivery of stem cell clinical trials to patients. CIRM awarded a $7,999,999 grant to help establish this site.

Stem cell and gene therapy research gets a good report card from industry leader

arm

Panel discussion at ARM State of the industry briefing: left to Right Robert Preti, Chair ARM; Jeff Walsh, bluebird bio; Manfred Rudiger, Kiadis Pharma; Barbara Sasu, Pfizer;  Thomas Farrell, Bellicum Pharmaceuticals. Photo courtesy ARM.

The state of the regenerative medicine field is strong and getting stronger. That was the bottom line verdict at the 2017 Cell and Gene Therapies State of the Industry briefing in San Francisco.

The briefing, an annual update on the field presented by the Alliance for Regenerative Medicine (ARM), gave a “by the numbers” look at the field and apart from one negative spot everything is moving in the right direction.

Robert Preti, Chair of ARM’s Board, said worldwide there are more than 750 regenerative companies working in the stem cell and gene therapy space. And those companies are increasingly moving the research out of the lab and into clinical trials in people.

For example, at the end of 2016 there were 802 clinical trials underway. That is a 21 percent growth over 2015. Those breakdown as follows:

Phase 1 – 271 (compared to 192 in 2015)

Phase 2 – 465 (compared to 376 in 2015)

Phase 3 – 66 (compared to 63 in 2015)

The bulk of these clinical trials, 45 percent, are focused on cancer. The second largest target, 11 percent, is on heart disease. The number of trials for neurological disorders and rare diseases are also growing in number.

Preti says the industry is at an important inflection point right now and that this growth is presenting new problems:

“The pipeline of products is robust and the technologies supporting that pipeline is even more robust. The technologies that are fueling the growth in clinical activity have accelerated so fast that we on the manufacturing side are playing catchup. We are at a point where we have to get serious about large scale commercial production.”

Preti also talked about “harmonization” of the regulatory process and the need to have a system that makes it easier for products approved for clinical trials in one country, to get approval for clinical trials in other countries.

Michael Werner, the executive director of ARM, said the organization has played a key role in helping promote the field and cited the recently passed 21st Century Cures Act as “a major win and a powerful statement of ARM’s leadership in this sector.”

But there was one area where the news wasn’t all positive, the ability of companies to raise capital. In 2015 companies raised $11 billion for research. In 2016 it was less than half of that, $5.3 billion.

With that somber note in mind it was appropriate that the panel discussion that followed the briefing was focused on the near-term and long-term challenges facing the field if it was to be commercially successful.

One of the big challenges was the issue of regulatory approval, and here the panel seemed to be more optimistic than in previous years.

Manfred Rüdiger of Kiadis Pharma said he was pleasantly surprised at how easy it was to work with different regulatory agencies in the US, Canada and Europe.

“We used them as a kind of free consultancy service, listening to their advice and making the changes they suggested so that we were able to use the same manufacturing process in Europe and Canada and the US.”

Jeff Walsh of bluebird bio, said the key to having a good working relationship with regulatory agencies like the Food and Drug Administration (FDA) is simple:

“Trust and transparency between you and the regulatory agencies is essential, it’s a critical factor in advancing your work. The agencies respond well when you have that trust. One thing we can’t be is afraid to ask. The agencies will tell you where their line is, but don’t be afraid to ask or to push the boundaries. This is new for everyone, companies and regulators, so if you are pushing it helps create the environment that allows you to work together to develop safe therapies that benefit patients.”

Another big issue was scalability in manufacturing; that it’s one thing to produce enough of a product to carry out a clinical trial but completely different if you are hoping to use that same product to treat millions of people spread out all over the US or the world.

And of course cost is always something that is front and center in people’s minds. How do you develop therapies that are not just safe and effective, but also affordable? How do companies ensure they will get reimbursed by health insurers for the treatments? No one had any simple answer to what are clearly very complex problems. But all recognized the need to start thinking about these now, long before the treatments themselves are even ready.

Walsh ended by saying:

“This is not just about what can you charge but what should you charge. We have a responsibility to engage with the agencies and ultimately the payers that make these decisions, in the same way we engage with regulatory agencies; with a sense of openness, trust and transparency. Too often companies wait too long, too late before turning to the payers and trying to decide what is appropriate to charge.”