Can CoRegen's Treg Platform Dismantle Solid Tumors' Immune Shield?

By Ray Dogum, Chief Editor, Drug Discovery Online

Key Takeaways

• CoRegen is pursuing an unconventional cell therapy strategy for solid tumors. Rather than engineering immune cells to directly attack cancer, its lead candidate, CRG-150, is designed to alter the tumor microenvironment by targeting regulatory T cells (Tregs), which tumors can exploit to evade immune surveillance.
• The company’s approach centers on SRC-3, a master regulatory gene linked to multiple immune-suppressive pathways. According to CoRegen, knocking out SRC-3 in Tregs can influence downstream checkpoint-related pathways, including PD-1, PD-L1, CTLA-4, LAG3, and CCR4.
• The platform is now facing its defining test. Following FDA clearance to advance CRG-150 into Phase 1/2a studies, CoRegen must demonstrate that the encouraging biology observed in preclinical models can produce meaningful outcomes in patients.

The immuno-oncology industry has spent the past decade engineering CAR-T cells, launching checkpoint inhibitors, and investing billions in stronger immune attacks against cancer. Although that strategy transformed outcomes in some blood cancers, solid tumors remain one of oncology’s toughest challenges.

CAR-T Therapy Still Hit-or-Miss

Many cell therapies still struggle in solid tumors because a highly suppressive tumor microenvironment can prevent immune cells from functioning. Following a $93M financing round last year, CoRegen is testing whether removing those biological barriers can make immunotherapy more effective.

That question sits at the center of CoRegen's strategy and is one of the reasons Sonal Kothari-Gupta, MD, PhD, joined the company as chief medical officer in 2025.

"If you work in solid tumors, you know that the tumor microenvironment is maybe the biggest enemy, for many effector cells, and that's why CAR T-cells occasionally work, but not all the time, and so it's always a hit-or-miss," Gupta said. "And based on everything that I've seen, it's really the tumor microenvironment.”

“CoRegen’s platform, basically directly targets the tumor microenvironment. So, one of the culprits is the regulatory T cell. So being able to target that by knocking out this gene called SRC-3, and changing the basic biology of the tumor, that was very exciting."

Gupta's career has tracked the evolution of advanced therapeutics. A physician trained in India, she earned a PhD in cancer biology and immunology from the University of Bradford before conducting postdoctoral research at Massachusetts General Hospital. Over the past decade, she has held leadership positions spanning cell therapy, gene therapy, gene editing, translational medicine, and immuno-oncology, most recently serving as senior vice president and head of clinical development at AffyImmune Therapeutics.

Targeting the Tumor’s Immune Shield

One of the biggest shifts occurring across oncology today is increased attention on the tumor microenvironment. Advances in single-cell sequencing, spatial biology, and molecular profiling have revealed that tumors are not simply masses of cancer cells. They are complex ecosystems containing immune cells, blood vessels, stromal networks, and signaling pathways that collectively influence disease progression and treatment response.

Among the most important players in that ecosystem are regulatory T cells, or Tregs.

Under normal circumstances, Tregs perform an essential function. They help prevent autoimmune disease by keeping the immune system from attacking healthy tissues. They are responsible for immunological tolerance. But tumors can exploit that same protective mechanism.

"Regulatory T cells have evolved to prevent autoimmunity," Gupta explained. "But what tumors have done is co-opt that pathway. They use regulatory T cells to form a shield, to basically hide from the immune system."

The idea of targeting suppressive immune cells has attracted growing interest across the industry, particularly as researchers seek new ways to improve outcomes in solid tumors where conventional immunotherapies have shown limitations.

A Bet On SRC-3

CoRegen's approach originates from decades of research conducted at Baylor College of Medicine, where investigators studied SRC-3, a gene involved in regulating multiple immune and cancer-related pathways.

While many immunotherapies target individual checkpoints such as PD-1, PD-L1, and CTLA-4, the company's hypothesis is that intervening further upstream could influence multiple pathways simultaneously.

"SRC-3 is the puppet master," Gupta said. "When you knock out SRC-3, you basically have a downstream effect on all the other individual immune checkpoint pathways."

According to the company, SRC-3 knockout affects several checkpoint-associated pathways, including PD-1, PD-L1, CTLA-4, LAG3, and CCR4. The strategy forms the basis of CRG-150, an investigational autologous cell therapy designed to disrupt the tumor-protective function of regulatory T cells.

Importantly, Gupta does not describe the therapy as a traditional cancer-killing cell product.

"Our cells do not directly kill the cancer," she said. "They enable the killing of cancer."

If that concept proves correct, the therapy could potentially complement rather than compete with other forms of immunotherapy.

The Industry Wants Proof, Not Promises

CoRegen enters the clinic at a time when biotech investors have become considerably more demanding.

In July 2025, CoRegen closed a $93.39 million private financing to support chemistry, manufacturing, and controls development, advance its SRC-3 knockout Treg program into clinical trials, and expand its leadership team.

Five years ago, platform technologies often attracted enthusiasm based on compelling biology alone. Today, investors and strategic partners are increasingly focused on mechanism of action, intellectual property, manufacturing readiness, regulatory strategy, and clinical evidence.

That shift is particularly relevant in immuno-oncology, where many programs have generated impressive mouse data only to fall short in human trials.

According to the company, preclinical studies demonstrated tumor eradication across multiple solid-tumor models, including pancreatic cancer.

Still, Gupta acknowledges the challenge ahead.

"Human beings are a lot more complex than mice," she said.

The Clinical Test Begins

As CRG-150 advances into Phase 1/2a development, the company plans to evaluate the safety and tolerability of the drug in relapsed/refractory HR+HER2- breast cancer, Triple Negative Breast Cancer (TNBC) and prostate cancer. They plan to closely examine not only safety and efficacy, but also the biological mechanisms underlying treatment response. The study is estimated to begin in November 2026.

Researchers intend to monitor cytokine changes, immune-cell populations, cellular persistence, pharmacodynamic markers, and tumor biopsies before and after treatment. The goal is to determine whether the microenvironmental changes observed in preclinical studies can be replicated in patients.

"We want to understand how the tumor microenvironment changes," Gupta said.

She hopes greater attention to immune regulation will broaden the field's focus beyond effector cells.

CRG-150 will test whether disarming tumor defenses, rather than building stronger cancer killers, can improve solid-tumor treatment.