OUR PIPELINE

A Different Kind of Cytokine Therapy

We are building a pipeline of novel immunotherapies that we believe will deliver on the promise of cytokine therapeutics for patients with cancer and autoimmune / inflammatory diseases.

Key:

Oncology
Autoimmune/Inflammation

Program

Indication(s)

Discovery
Pre-clinical

IND Enabling

Phase 1

Phase 2

Phase 3

Worldwide
Rights

Engineered Partial Agonists and Surrogate Cytokine Agonists (SCAs)

STK-012: α/β-Biased IL-2 Partial Agonist

NSCLC, RCC, and other select solid tumors

Phase 1

STK-026: IL-12 Partial Agonist

Solid tumors

IND Enabling

IL-10 Program

Inflammatory diseases

Discovery
Pre-clinical

IL-22 Program

Inflammatory and metabolic diseases

Discovery
Pre-clinical

Undisclosed

Autoimmune diseases

Discovery
Pre-clinical

Undisclosed

Undisclosed

Discovery
Pre-clinical

Cytokine-Inducible Cell Therapies Using orthoIL-2 Technology

SYNCAR-001 + STK-009

(CD19 orthoCAR-T + orthoIL-2)

CD19+ malignancies

Phase 1

± lymphodepletion

SYNCAR-001 + STK-009

(CD19 orthoCAR-T + orthoIL-2)

Systemic lupus erythematosus (SLE) and lupus nephritis (LN)

Phase 1

no lymphodepletion

SYNCAR-002 + STK-009

(GPC3 orthoCAR-T + orthoIL-2)

Hepatocellular carcinoma

IND Enabling

Other cell therapies

Undisclosed

Discovery
Pre-clinical

Synthekine Inc. (“Synthekine”) is committed to developing safe and effective medicines designed to improve the treatment of cancer, autoimmune and inflammatory diseases.

In general, all new drug product candidates must be reviewed and approved by the U.S. Food and Drug Administration (“FDA”) before they can become commercially available in the United States for treating appropriate patients. Drugs that have not been approved by FDA may or may not be effective as a treatment and may cause unexpected serious side effects.

As a general policy, Synthekine’s investigational drugs are currently accessible only to subjects participating in a Synthekine-sponsored clinical trial, that is, only to subjects who meet the clinical trial criteria and are enrolled in an ongoing clinical trial. A clinical trial is a controlled research study designed to evaluate whether an investigational drug is safe and effective for its intended use(s). Data generated from clinical trials are then evaluated by FDA to determine whether the investigational drug can be approved for commercialization. We encourage patients who are interested to first discuss with their treating physician about whether participation in a clinical trial is appropriate for them. Whenever possible, Synthekine encourages patients who are eligible for participation in a clinical trial to participate in that trial, which offers the best opportunity for patients to access Synthekine’s investigational drugs before regulatory approval. Additional information about Synthekine’s ongoing clinical trials can be found at https://clinicaltrials.gov and at https://www.synthekine.com/our-pipeline/#pipeline.

However, Synthekine recognizes that some individuals who are not enrolled in a Synthekine-sponsored clinical trial may have a serious or immediately life-threatening disease or condition for which Synthekine is developing an investigational drug and for which the individual may have no satisfactory therapeutic alternatives. In these rare cases, Synthekine may consider providing access to one (or more) of its investigational drugs outside of a Synthekine-sponsored clinical trial to a limited number of physicians who are treating such individuals through a process called “expanded access,” also known as “compassionate use.” Physicians located in the United States may find additional information regarding expanded access to investigational products by visiting FDA’s website at Expanded Access: Information for Physicians. If a treating physician believes expanded access may be an available and appropriate option for their patient, the physician may submit an inquiry for more information on behalf of the patient by contacting Synthekine at clinicaltrials@synthekine.com. Synthekine expects to acknowledge receipt of inquiries within five business days.

Currently, none of Synthekine’s investigational products are available for expanded access.

Pursuant to the 21st Century Cures Act, Synthekine may revise this expanded access policy at any time and the posting of this expanded access policy by Synthekine shall not serve as a guarantee of access to any specific investigational drug for any individual.

STK-012

Our most advanced product candidate, STK-012, is a modified IL-2 cytokine. IL-2 is a master modulator of the immune system, stimulating cell proliferation, survival and differentiation in a diverse set of immune cells. A recombinant IL-2 therapy, aldesleukin (marketed as Proleukin), is approved for and has compelling efficacy in certain cancers, however it is not widely used because it can only be administered for a short course of therapy due to risk for severe toxicities such as capillary leak syndrome, or CLS.

The IL-2 receptor is expressed on the surface of most lymphocytes, in particular T cells, NK cells and B cells, and contains three possible protein chains: (i) IL-2Rα, or CD25; (ii) IL-2Rß, or CD122; and (iii) IL-2Rγ, or CD132. The trimeric, high-affinity IL-2 receptor employs all three of these chains while the dimeric, intermediate-affinity IL-2 receptor employs only the IL-2Rβ and IL-2Rγ chains. Tumor antigen-activated T cells express the trimeric, high-affinity IL-2 receptor at significantly higher concentrations than any other lymphocyte.

We believe the efficacy of IL-2 is primarily driven by the proliferation and activation of tumor antigen-activated T cells, and we have engineered STK-012 to preferentially stimulate these tumor-killing T cells. In contrast, NK cells and naïve T cells do not express IL-2Rα and express only the dimeric, intermediate affinity IL-2 receptor. We and others have demonstrated that IL-2-related toxicities, in particular CLS, are mainly driven by the non-specific activation of various lymphocytes such as NK cells. Therefore, we designed STK-012 as an α/ß-biased IL-2 partial agonist with the following three characteristics:

  • Proliferate and activate antigen-activated T cells
  • Avoid toxicity driven by broad stimulation of naïve T cells and NK cells
  • Improve the CD8+ T cell to regulatory T cell ratio in the tumor microenvironment

In syngeneic mouse efficacy models, the mouse surrogate of STK-012 demonstrated superior tumor regression compared to both wild-type mouse IL-2 and a non-α-IL-2 agent. Moreover, in mouse toxicity models, the mouse surrogate of STK-012 was well tolerated, with no cases of CLS. In contrast, wild-type IL-2 and non-α-IL-2 agents induced CLS and led to significant lethality. In non-human primates, or NHPs, STK-012 demonstrated significantly improved pharmacokinetics, or PK, and toxicity profile versus both aldesleukin and a non-a IL-2 agent, representing a different approach by biasing IL-2 towards the dimeric, intermediate-affinity IL-2 receptor.

STK-012 is now being investigated in a Phase 1b study (NCT05098132).

STK-009 + SYNCAR-001

Our lead cytokine-inducible cell therapy candidate using orthoIL-2 technology is SYNCAR-001, an autologous CD19 orthoCAR-T cell combined with STK-009, our orthoIL-2 ligand. Several CAR T cell therapies targeting CD19 are FDA-approved for the treatment of advanced, refractory hematologic malignancies such as lymphoma, and can lead to long-term remissions and cures for patients. In addition, recently published data on the use of CD19 CAR-T cells in autoimmune disease has shown extraordinary efficacy and highlights both the unmet need and therapeutic potential of STK-009 + SYNCAR-001 in lupus and other B-cell mediated diseases.

Unlike other CD19 CAR-T therapies, SYNCAR-001 also expresses an engineered IL-2 receptor beta subunit, or hoRß, that is designed to only receive a signal from STK-009, our engineered orthogonal IL-2 cytokine. STK-009 was designed specifically to stimulate hoRß-expressing cells. In the absence of STK-009, SYNCAR-001 functions as a current generation CD19 CAR-T cell. However, in the presence of STK-009, a unique IL-2 signal is delivered to the SYNCAR-001 cells with high specificity while avoiding stimulation of normal lymphocytes expressing the endogenous IL-2 receptors, such as NK cells, native T cells or Tregs.

We believe SYNCAR-001 + STK-009 has the potential to address the key limitations of current CD19 CAR-T cell therapies by:

  • Increasing the activity of CAR-T cells to improve the magnitude of clinical responses
  • Increasing CAR-T expansion and persistence, thereby improving the durability of clinical responses
  • Enabling lower doses of CAR-T cells to reduce toxicity
  • Eliminating lymphodepletion to lower the risk of infection and reach more patients

In xenograft efficacy models, SYNCAR-001, followed by multiple doses of STK-009, led to significantly more complete responses, or CRs, compared to a conventional CD19 CAR-T cell therapy. STK-009 + SYNCAR-001 also demonstrated CRs in bulky lymphoma models that are typically refractory to CD19 CAR-T therapies. Syngeneic mouse models also demonstrate the ability to clear tumors or eliminate B cells in the absence of lymphodepletion. In NHP studies, STK-009 did not induce toxicity or immune activation of native lymphocytes.

STK-009 + SYNCAR-001 is now being investigated in a Phase 1 study (NCT05665062). STK-009 dose escalation is ongoing and the fixed dose of SYNCAR-001 cells is significantly lower than traditional CD19 CAR-T therapies. The initial clinical investigation is in CD19+ hematologic malignancies. Given the promise for the mechanism of SYNCAR-001 in B-cell mediated autoimmune diseases, such as systemic lupus erythematosus (SLE), we plan to expand the development into non-renal SLE and lupus nephritis (LN). Across both cancer and autoimmune indications, we will treat patients without lymphodepletion.

Additional Programs

In addition to our lead programs, we have several programs in preclinical development, including our IL-12 partial agonist for the treatment of cancer and our IL-22 partial agonist for the treatment of inflammatory and metabolic disease. We are also extending our orthogonal cytokine-inducible cell therapy platform to CARs against solid tumor targets, such as GPC3, to pair with STK-009. Finally, we have multiple surrogate cytokine agonists in preclinical exploration internally as well as in partnerships.