CIRM-funded trial for blood cancer releases promising new data


A CIRM-funded trial conducted by Oncternal Therapeutics in collaboration with UC San Diego released an interim clinical data update for patients with mantle cell lymphoma (MCL), a type of blood cancer.

The treatment being developed involves an antibody called cirmtuzumab (named after yours truly) being used with a cancer fighting drug called ibrutinib. The antibody recognizes and attaches to a protein on the surface of cancer stem cells. This attachment disables the protein, which slows the growth of the blood cancer and makes it more vulnerable to anti-cancer drugs.

Here are the highlights from the new interim clinical data:

  • Patients had received a median of two prior therapies before participating in this study including chemotherapy; autologous stem cell transplant (SCT); autologous SCT and CAR-T therapy; autologous SCT and allogeneic SCT; and ibrutinib with rituximab, a different type of antibody therapy.
  • 6 of the 12 patients in the trial experienced a Complete Response (CR), which is defined as the disappearance of all signs of cancer in response to treatment.
  • All six CRs are ongoing, including one patient who has remained in CR for more than 21 months past treatment.
  • Four of the six patients achieved CRs within four months on the combination of cirmtuzumab and ibrutinib.
  • Of the remaining 6 patients, 4 experienced a Partial Response (PR), which is defined as a decrease in the extent of the cancer in the body.
  • The remaining two patients experienced Stable Disease (SD), which is defined as neither an increase or decrease in the extent of the cancer.

The full interim clinical data update can be viewed in the press release here.

Four CIRM Funded Trials Release Results at 2019 ASH Meeting

With more than 17,000 members from nearly 100 countries, the American Society of Hematology (ASH) is an organization composed of clinicians and scientists around the world working to conquer various blood diseases. Currently, they are having their 61st Annual ASH Meeting to highlight some of the exciting work going on in the field. Four of our CIRM funded trials have released promising results at this conference and we wanted to take the opportunity to highlight them below.

Sangamo Therapeutics

Sangamo Therapeutics is conducting a CIRM-funded clinical trial for beta-thalassemia, a severe form of anemia caused by mutations in the hemoglobin gene. The therapy Sangamo is testing takes a patient’s own blood stem cells and, using a gene-editing technology called zinc finger nuclease (ZFN), provides a functional copy of the hemoglobin gene. These modified cells are then given back to the patient. The company announced preliminary results from their first three patients treated. in the clinical trials at the ASH 2019 Conference as well.

Some of the highlights are the following:

  • The first three patients experienced prompt hematopoietic reconstitution, meaning that their supply of blood stem cells was restored.
  • The first three patients experienced no clonal hematopoiesis, meaning that the blood stem cells did not create cells with mutations in the DNA
  • Additional study results are expected in late 2020 once enrollment is complete and all six patients have longer follow-up

You can read more detailed results regarding the first three patients in the press release.

Forty Seven, Inc.

In another CIRM funded trial, Forty Seven, Inc. is testing a treatment for myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). The treatment involves an antibody called magrolimab in combination with the chemotherapy drug azacitidine. Cancer cells express a signal that send a “don’t eat me” message to white blood cells that are part of the immune system designed to “eat” and destroy unhealthy cells. Magrolimab works by blocking the signal, enabling the body’s own immune system to detect these evasive cancer cells. The goal is to use both magrolimab and azacitidine to make the cancer stem cells vulnerable to being attacked and destroyed by the immune system.

Of the 46 patients evaluated, 24 patients had untreated higher-risk MDS and 22 patients had untreated AML. None of the patients were eligible for treatment with chemotherapy.

In higher-risk MDS, the overall response rate (ORR), which is the proportion of patients in a trial whose tumor is destroyed or significantly reduced by a treatment, was 92%.

Within this group of patients with an ORR, the following was observed:

  • 12 patients (50%) achieved a complete response (CR), meaning that they experienced a disappearance of all signs of cancer in response to treatment.
  • Two patients (8%) achieved hematologic (blood) improvement. 
  • Additionally, two patients (8%) achieved stable disease, meaning the cancer is neither increasing nor decreasing in extent or severity.

In untreated AML, the ORR was 64% and the following was observed within this group patients with an ORR:

  • Nine patients (41%) achieved a CR
  • Three patients (14%) achieved a CR with an incomplete blood count recovery (CRi)
  • One patient (5%) achieved a morphologic leukemia-free state (MLFS), which is defined as the disappearance of all cells with morphologic characteristics of leukemia, accompanied by bone marrow recovery, in response to treatment.
  • Seven patients (32%) achieved stable disease (SD)

The median time to response among MDS and AML patients treated with the combination was 1.9 months.

More details regarding these results are available via the news release.

Oncternal Therapeutics

Onceternal Therapeutics, which is conducting a CIRM-funded trial for a treatment for lymphoma and leukemia, presented results at the 2019 ASH Meeting. The treatment involves an antibody called cirmtuzumab (named after yours truly) being used with a cancer fighting drug called ibrutinib. The antibody recognizes and attaches to a protein on the surface of cancer stem cells. This attachment disables the protein, which slows the growth of the leukemia and makes it more vulnerable to anti-cancer drugs.

Some of the results presented are summarized as follows:

  • Twenty-nine of the 34 patients achieved a response, for an overall best objective response rate of 85%.
  • One patient achieved a complete response (CR) and remained in remission six months after completion of the trial and discontinuation of all anti-CLL therapy. In addition, three patients met radiographic and hematologic response criteria for Clinical CR.
  • Five patients had stable disease.
  • The total clinical benefit rate was 100%.
  • None of the patients died or saw their disease progress.
  • Patients achieved responses rapidly, with 68% of patients achieving a clinical response by three months on the combination therapy.
  • The rise in leukemic cell counts that is typically seen in the first six months with ibrutinib by itself was blunted with the addition of cirmtuzumab, and leukemic cell counts returned toward baseline and normal levels rapidly.

You can read more about these results in the official press release.

Rocket Pharmaceuticals

Last, but not least, Rocket Pharmaceuticals presented results at the 2019 ASH Conference related to a CIRM-funded trial for Leukocyte Adhesion Deficiency-I (LAD-I), a rare pediatric disease caused by a mutation in a specific gene that affects the body’s ability to combat infections. As a result, there is low expression of neutrophil (CD18). The company is testing a treatment that uses a patient’s own blood stem cells and inserts a functional version of the gene.  These modified stem cells are then reintroduced back into the patient. The goal is to establish functional immune cells, enabling the body to combat infections.  

Here are some of the highlights from the presentation:

  • Initial results from the first pediatric patient treated demonstrate early evidence of safety and potential effectiveness. 
  • The patient exhibited early signs of engraftment
  •  The patient also displayed visible improvement of multiple disease-related skin lesions after receiving therapy
  •  No safety issues related to administration have been identified

More detailed results on this trial are available via the news release.

CIRM-funded clinical trial shows encouraging results for patients with chronic lymphocytic leukemia & mantle cell lymphoma

Illustration courtesy of Oncternal Therapeutics

I often joke that my job here at CIRM is to be the official translator for the stem cell agency. I have to translate complex science into everyday English that people without a science background – that includes me – can understand.

Think I’m joking? Try making sense of this.

See what I mean. If you are a scientist this is not only perfectly clear, it’s also quite exciting. But for the rest of us……..

Actually, it is really quite exciting news. It’s about a CIRM-funded clinical trial being run by Oncternal Therapeutics to treat people with chronic lymphocytic leukemia (CLL), a kind of cancer where our body makes too many white blood cells. The study is using a combination therapy of Cirmtuzumab (a monoclonal antibody named after us because we helped fund its development) and ibrutinib, a conventional therapy used to treat cancers like CLL.

Cirmtuzumab recognizes and then attaches itself to a protein on the surface of cancer stem cells that the cancer needs to survive and spread. This attachment disables the protein (called ROR1) which slows the growth of the leukemia and makes it more vulnerable to anti-cancer drugs like ibrutinib.

In this Phase 1/2 clinical trial 12 patients were given the combination therapy for 24 weeks or more, making them eligible to determine how effective, or ineffective, the therapy is:

  • 11 of the 12 patients had either a partial response – meaning a reduction in the amount of detectable cancer – or a complete response to the treatment – meaning no detectable cancer.
  • None of the patients saw their cancer spread or grow
  • Three of the patients completed a year of treatment and they all showed signs of a complete response including no enlarged lymph nodes and white blood cell counts in the normal range.  

The combination therapy is also being used to treat people with Mantle Cell Lymphoma (MCL), a rare but fast-growing form of blood cancer. The results from this group, while preliminary, are also encouraging. One patient, who had experienced a relapse following a bone marrow transplant, experienced a complete response after three months of cirmtuzumab and ibrutinib.  

The data on the clinical trial was presented at a poster session (that’s the poster at the top of this blog) at the annual meeting of the American Society of Clinical Oncology.

In a news release Dr. James Breitmeyer, the President & CEO of Oncternal, said the results are very encouraging:  

“These data presented today, taken together with an earlier Phase 1 study of cirmtuzumab as a monotherapy in relapsed/refractory CLL, give us increased confidence in the potential for cirmtuzumab as a treatment for patients with ROR1-expressing lymphoid malignancies, particularly in combination with ibrutinib as a potential treatment for patients with CLL and MCL. We believe that the data also help to validate the importance of ROR1 as a therapeutic target,”

Confusing cancer to kill it

Kipps

Thomas Kipps, MD, PhD: Photo courtesy UC San Diego

Confusion is not a state of mind that we usually seek out. Being bewildered is bad enough when it happens naturally, so why would anyone actively pursue it? But now some researchers are doing just that, using confusion to not just block a deadly blood cancer, but to kill it.

Today the CIRM Board approved an investment of $18.29 million to Dr. Thomas Kipps and his team at UC San Diego to use a one-two combination approach that we hope will kill Chronic Lymphocytic Leukemia (CLL).

This approach combines two therapies, cirmtuzumab (a monoclonal antibody developed with CIRM funding, hence the name) and Ibrutinib, a drug that has already been approved by the US Food and Drug Administration (FDA) for patients with CLL.

As Dr. Maria Millan, our interim President and CEO, said in a news release, the need for a new treatment is great.

“Every year around 20,000 Americans are diagnosed with CLL. For those who have run out of treatment options, the only alternative is a bone marrow transplant. Since CLL afflicts individuals in their 70’s who often have additional medical problems, bone marrow transplantation carries a higher risk of life threatening complications. The combination approach of  cirmtuzumab and Ibrutinib seeks to offer a less invasive and more effective alternative for these patients.”

Ibrutinib blocks signaling pathways that leukemia cells need to survive. Disrupting these pathways confuses the leukemia cell, leading to its death. But even with this approach there are cancer stem cells that are able to evade Ibrutinib. These lie dormant during the therapy but come to life later, creating more leukemia cells and causing the cancer to spread and the patient to relapse. That’s where cirmtuzumab comes in. It works by blocking a protein on the surface of the cancer stem cells that the cancer needs to spread.

It’s hoped this one-two punch combination will kill all the cancer cells, increasing the number of patients who go into complete remission and improve their long-term cancer control.

In an interview with OncLive, a website focused on cancer professionals, Tom Kipps said Ibrutinib has another advantage for patients:

“The patients are responding well to treatment. It doesn’t seem like you have to worry about stopping therapy, because you’re not accumulating a lot of toxicity as you would with chemotherapy. If you administered chemotherapy on and on for months and months and years and years, chances are the patient wouldn’t tolerate that very well.”

The CIRM Board also approved $5 million for Angiocrine Bioscience Inc. to carry out a Phase 1 clinical trial testing a new way of using cord blood to help people battling deadly blood disorders.

The standard approach for this kind of problem is a bone marrow transplant from a matched donor, usually a family member. But many patients don’t have a potential donor and so they often have to rely on a cord blood transplant as an alternative, to help rebuild and repair their blood and immune systems. However, too often a single cord blood donation does not have enough cells to treat an adult patient.

Angiocrine has developed a product that could help get around that problem. AB-110 is made up of cord blood-derived hematopoietic stem cells (these give rise to all the other types of blood cell) and genetically engineered endothelial cells – the kind of cell that lines the insides of blood vessels.

This combination enables the researchers to take cord blood cells and greatly expand them in number. Expanding the number of cells could also expand the number of patients who could get these potentially life-saving cord blood transplants.

These two new projects now bring the number of clinical trials funded by CIRM to 35. You can read about the other 33 here.