Sweet 16 and counting for stem cell clinical trial

Dr. Judy Shizuru: Photo courtesy Jasper Therapeutics

Over the years the California Institute for Regenerative Medicine (CIRM) has invested a lot in helping children born with severe combined immunodeficiency (SCID), a fatal immune disorder. And we have seen great results with some researchers reporting a 95 percent success rate in curing these children.

Now there’s more encouraging news from a CIRM-funded clinical trial with Jasper Therapeutics. They have announced that they have tested their approach in 16 patients, with encouraging results and no serious adverse events.

Let’s back up a little. Children born with SCID have no functioning immune system, so even a simple infection can prove life threatening. Left untreated, children with SCID often die in the first few years of life. Several of the approaches CIRM has funded use the child’s own blood stem cells to help fix the problem. But at Jasper Therapeutics they are using another approach. They use a bone marrow or hematopoietic stem cell transplant (HCT).   This replaces the child’s own blood supply with one that is free of the SCID mutation, which helps restore their immune system.

However, there’s a problem. Most bone marrow transplants use chemotherapy or radiation to destroy the patient’s own unhealthy blood stem cells and make room for the new, healthy ones. It can be effective, but it is also toxic and complex and can only be performed by specialized teams in major medical centers, making access particularly difficult for poor and underserved communities.

To get around that problem Jasper Therapeutics is using an antibody called JSP191 – developed with CIRM funding – that directs the patient’s own immune cells to kill diseased blood stem cells, creating room to transplant new, healthy cells. To date the therapy has already been tested in 16 SCID patients.

In addition to treating 16 patients treated without any apparent problems,  Jasper has also been granted Fast Track Designation by the US Food and Drug Administration. This can help speed up the review of treatments that target serious unmet conditions. They’ve also been granted both Orphan and Rare Pediatric Disease designations. Orphan drug designation qualifies sponsors for incentives such as tax credits for clinical trials. Rare Pediatric Disease designation means that if the FDA does eventually approve JSP191, then Jasper can apply to receive a priority review of an application to use the product for a different disease, such as someone who is getting a bone marrow transplant for sickle cell disease or severe auto immune diseases.

In a news release, Ronald Martell, President and CEO of Jasper Therapeutics said:

“The FDA’s Fast Track designation granted for JSP191 in Severe Combined Immunodeficiency (SCID) reinforces the large unmet medical need for patients with this serious disease. Along with its previous designations of Orphan and Rare Pediatric Disease for JSP191, the FDA’s Fast Track recognizes JSP191’s potential role in improving clinical outcomes for SCID patients, many of whom are too fragile to tolerate the toxic chemotherapy doses typically used in a transplant.”

Fast Track Designation for a therapy making transplants safer for children with a fatal immune disorder

Bone marrow transplant

For children born with severe combined immunodeficiency (SCID) life can be very challenging. SCID means they have no functioning immune system, so even a simple infection can prove life threatening. Left untreated, children with SCID often die in the first few years of life.

There are stem cell/gene therapies funded by the California Institute for Regenerative Medicine (CIRM), such as ones at UCLA and UCSF/St. Judes, but an alternative method of treating, and even curing the condition, is a bone marrow or hematopoietic stem cell transplant (HCT). This replaces the child’s blood supply with one that is free of the SCID mutation, which helps restore their immune system.

However, current HCT methods involve the use of chemotherapy or radiation to destroy the patient’s own unhealthy blood stem cells and make room for the new, healthy ones. This approach is toxic and complex and can only be performed by specialized teams in major medical centers, making access particularly difficult for poor and underserved communities.

To change that, Dr. Judy Shizuru at Stanford University, with CIRM funding, developed an antibody that can direct the patient’s own immune cells to kill diseased blood stem cells, creating the room needed to transplant new, healthy cells. The goal was to make stem cell transplants safer and more effective for the treatment of many life-threatening blood disorders.

That approach, JSP191, is now being championed by Jasper Therapeutics and they just got some very good news from the Food and Drug Administration (FDA). The FDA has granted JSP191 Fast Track Designation, which can speed up the review of therapies designed to treat serious conditions and fill unmet medical needs.

In a news release, Ronald Martell, President and CEO of Jasper Therapeutics, said this is good news for the company and patients: “This new Fast Track designation recognizes the potential role of JSP191 in improving clinical outcomes for these patients and will allow us to more closely work with the FDA in the upcoming months to determine a path toward a Biologics License Application (BLA) submission.”

Getting a BLA means Jasper will be able to market the antibody in the US and make it available to all those who need it.

This is the third boost from the FDA for Jasper. Previously the agency granted JSP191 both Orphan and Rare Pediatric Disease designations. Orphan drug designation qualifies sponsors for incentives such as tax credits for clinical trials. Rare Pediatric Disease designation means that if the FDA does eventually approve JSP191, then Jasper can apply to receive a priority review of an application to use the product for a different disease, such as someone who is getting a bone marrow transplant for sickle cell disease or severe auto immune diseases.

CIRM-supported therapy for blood cancers gets FDA fast track

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People often complain about how long it can take to turn a scientific discovery into an approved therapy for patients. And they’re right. It can take years, decades even. But for Immune-Onc Therapeutics the path to FDA approval may just have been shortened.

Back in April of 2021 the California Institute for Regenerative Medicine (CIRM) approved investing $6 million in Immune-Onc to conduct a clinical trial for patients with acute myeloid leukemia (AML) and chronic myelomonocytic leukemia (CMML). AML and CMML are both types of blood cancer. AML affects approximately 20,000 people in the United States each year and has a 5-year survival rate of about 25 percent. Anywhere from 15-30 percent of CMML cases eventually progress into AML.

Dr. Paul Woodard and his team are treating patients with an antibody therapy called IO-202 that targets leukemic stem cells.  The antibody works by blocking a signal named LILRB4 which is associated with decreased rates of survival in AML patients.  The goal is to attain complete cancer remissions and prolonged survival.

Well, they must be doing something right because they just received Fast Track designation from the US Food and Drug Administration (FDA) for IO-202. Getting this designation is a big deal because its goal is to speed up the development and review of drugs to treat serious conditions and fill an unmet medical need to get important new medicines to patients earlier.

Getting a Fast Track designation means the team at Immune-Onc may be:

  • Eligible for more written communications and even face-to-face meetings with the FDA to discuss the development plan of IO-202
  • Eligible for Accelerated Approval and Priority Review if relevant criteria are met, which may result in faster approval.

In a press release Dr. Woodard said this was great news.  “We are pleased that the FDA has granted IO-202 Fast Track designation in recognition of its potential to improve outcomes for people with relapsed or refractory AML. We look forward to working closely with the FDA to accelerate the clinical development of IO-202, which is currently being evaluated as a monotherapy and in combination with other agents in a Phase 1 dose escalation and expansion trial in patients with AML with monocytic differentiation and in chronic myelomonocytic leukemia (CMML).”

The FDA also granted IO-202 Orphan Drug Designation for treatment of AML in 2020. That’s defined as a therapy that’s intended for the treatment, prevention or diagnosis of a rare disease or condition, affecting less than 200,000 persons in the US.

Getting Orphan Drug Designation qualifies Immune-Onc for incentives including tax credits for clinical trials and the potential for seven years of market exclusivity if and when it is fully approved by the FDA.

Prime Time for Rocket

Rocket Pharmaceuticals, a company that specializes in developing genetic therapies for rare childhood disorders, just got a big boost from the European Medicines Agency (EMA). They were given a Priority Medicines (PRIME) designation for their therapy for Leukocyte Adhesion Deficiency-1 (LAD-1).

CIRM is funding ($6.56 million) Rocket’s clinical trial for LAD-I, an immune disorder that leaves patients vulnerable to repeated infections that often results in death within the first two years of life. The therapy involves taking some of the child’s own blood stem cells and, in the lab, correcting the mutation that causes LAD-I, then returning those cells to the patient. Hopefully those blood stem cells then create a new, healthy blood supply and repair the immune system.

The therapy, called RP-L201, is already showing promise in the clinical trial, hence the PRIME designation. The program was set up to help speed up development and evaluation of therapies that could help patients who have limited treatment options. Getting a PRIME designation means it is considered a priority by EMA and could reach patients sooner.

In the US, Rocket has won similar recognition from the Food and Drug Administration (FDA) and has been granted Regenerative Medicine Advanced Therapy (RMAT), Rare Pediatric Disease, and Fast Track designations.

In a news release Kinnari Patel, President and Chief Operating Officer of Rocket, said the designation showed that regulators understand the urgent need to develop a therapy for patients with LAD-1. “More than half of LAD-I patients suffer with a severe variant in which mortality occurs in up to 75% of young children who don’t receive a successful bone marrow transplant by the age of two. Securing all possible accelerated designations will enable us to collaborate with both the FDA and EMA to speed the development and delivery of a potential treatment for these patients.  We look forward to sharing initial Phase 2 data from our potentially registration-enabling LAD-I trial in the second quarter of 2021.”

That trial has now completed enrolling patients (nine altogether) but their treatments are not yet complete. LAD-1 patients with severe disease have low levels of a key protein called CD18, usually less than 2%. Of the first three patients treated in this trial CD18 levels are all higher than the 4-10% threshold considered necessary for these children to survive into adulthood. Another encouraging sign is that there were no serious side effects from the therapy.

Obviously there is still a long way to go before we know if this therapy really works, but the PRIME designation – along with the similar ones in the US – are recognition that this is a very promising start.