Closely held Nimbus Therapeutics is designing and developing precisely tailored small molecule medicines for challenging targets by leveraging a unique strategy that combines computational chemistry technologies with machine learning-based predictive modeling.
“We’re not just a company with great tools—Nimbus is a science-first biotech company that has proven we can turn those capabilities into real medicines that may change lives,” Abbas Kazimi, CEO of Nimbus, says in an interview with BioTuesdays.
“What we’ve built is exciting. We’ve combined disciplined execution, smart capital use, and fundamentally great science. We’ve advanced multiple internally designed programs into the clinic—delivering strong returns for our investors,” he adds.
Mr. Kazimi explains that Nimbus operates at the intersection of computational chemistry and deep biology. Its discovery engine is anchored in a compute-first approach, using high-performance, physics-based simulations to guide design decisions rather than relying on intuition. This includes advanced protein structure analysis, molecular simulations, machine learning-informed predictions, and deep data analytics—all within a target-centric framework.
“By layering AI and machine learning into our ‘design-make-test-analyze’ process, we’ve supercharged our discovery engine—allowing us to identify drug candidates in a way that is truly meaningful,” he says.
These atomic-level insights empower Nimbus to create precision molecules that deepen understanding of target biology and define optimal pharmacological profiles. The result is a streamlined path to clinical candidates with refined molecular attributes, built to test hypotheses with clarity and speed.
Through a rigorous selection process that integrates biology, chemistry, pharmacology, and translational medicine, Nimbus identifies difficult-to-drug targets with structural tractability, clear unmet need, and blockbuster potential – then advances optimally designed small molecule therapies into the clinic.
“Our focus is on impact. Every one of our candidates is based on thoughtful target selection, and each one has the potential to affect broad patient populations,” Mr. Kazimi asserts.
He clarifies that speed alone isn’t the objective. “While AI accelerates R&D, for us it’s about precision therapy—identifying the right molecule that will truly matter for patients.”
Focused on precision medicine spanning immunology, oncology, and metabolism, the company leverages its discovery engine to drive fundamental target selection. “We don’t chase every opportunity. We pursue areas where we can move fast, manage risk, and deliver clinical impact,” Mr. Kazimi says.
“Every one of our programs is rooted in thoughtful target choice, executed with high-performance computational tools, and built on world-class chemistry. That’s our roadmap for the future,” he adds.
Currently, all four Nimbus-discovered programs that have entered the clinic remain active in clinical trials:
- A selective, allosteric ACC inhibitor—acquired by Gilead—currently in Phase 2b studies for metabolic dysfunction-associated steatohepatitis (MASH)
- A selective, allosteric TYK2 inhibitor—acquired by Takeda—currently in multiple Phase 2/3 studies for various indications
- A selective, non-checkpoint HPK1 inhibitor in a Phase 1/2 study for advanced solid tumors
- A selective, potent, non-covalent inhibitor of Werner syndrome helicase (WRN) currently in a Phase 1/2 study for microsatellite instability high (MSI-H) solid tumors
Mr. Kazimi highlights that Nimbus is pioneering a potential best-in-class WRN helicase inhibitor in oncology. The company is developing an oral compound called NDI-219216 for patients who have MSI-H tumors—common in colorectal, gastric, and endometrial cancers.
“These MSI-H tumors have defects in DNA mismatch repair, which creates massive replication stress. WRN helps these tumors survive by stabilizing the DNA during replication—but if you block WRN, the tumor will collapse under its own instability. And, because normal cells don’t rely on WRN, it allows us to deliver potent anti-tumor activity with minimal toxicity.”
At the 36th EORTC-NCI-AACR Symposium in October 2024, Nimbus presented the first preclinical data of its novel WRN inhibitor, showing that daily oral dosing of NDI-219216 resulted in significant tumor regression and complete responses at low oral doses in MSI-H tumor models refractory to immunotherapy and chemotherapy. “These results were powerful and promising and really gave us the conviction to take this mechanism to the clinic,” Mr. Kazimi says.
The company announced the launch of its Phase 1/2 clinical trial of NDI-219216 in April 2025 to evaluate safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary anti-tumor activity.
“We believe how you drug WRN really matters. While there are no approved drugs for WRN, some companies are pursuing covalent compounds, but they come with some trade-offs around safety and resistance,” Mr. Kazimi notes. “They may also be vulnerable to resistant mutations. Our non-covalent inhibitor binds to a distinct WRN site, maintains activity even if there are mutations, and offers durability and resistance advantages.”
“Nimbus is poised to lead this space with a differentiated, durable, and scalable approach,” he adds.
In immunology, Nimbus is unlocking the salt-inducible kinase (SIK) pathway—a novel approach to modulating immune balance. “We asked ourselves—can we drug a SIK pathway by going after an isoform-specific molecule? The answer was yes, and that’s what we’re pursuing,” Mr. Kazimi says.
For example, in diseases where aberrant cell programming drives pathology, SIK2 inhibitors have the potential to halt damage and promote recovery. SIK2 simultaneously reduces pro-inflammatory cytokines (like TNF-α, IL-6, IL-12, IL-23) and boosts IL-10, a powerful anti-inflammatory signal that restores immune homeostasis.
“This isn’t just putting the brakes on inflammation—it’s hitting reset on the whole immune system. And with our compound, we’re seeing both cytokine suppression and IL-10 elevation—that’s not just great biology, it’s best-in-class potential,” he points out.
One of Nimbus’ key differentiators is its capital-efficient model that delivers an LLC business structure, which enables asset-by-asset value creation and strategic exits. “With our model, we’ve raised more than $633 million privately and returned more than $4.1 billion to investors and employees,” Mr. Kazimi says. “We’ve executed more than $7 billion in M&A and closed licensing deals exceeding $1.5 billion.”
Looking ahead, Mr. Kazimi emphasizes that Nimbus is just getting started. “Drug discovery is a team sport. We have built a really strong foundation of trust and leadership with a veteran group of scientists, executives, and investors. Together we have an unwavering focus on science, clinical momentum, and a growing pipeline.”
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