Welcome to this week's BioIntel Weekly Brief. Major M&A transactions defined the capital landscape as Merck committed $6.7 billion for Terns Pharmaceuticals' leukemia program and Gilead deployed $1.7 billion to acquire Ouro Medicines' immune-reset platform. Regulatory activity was equally concentrated—the FDA approved two gene therapies for rare diseases while issuing a safety warning on Parkinson's medications and rebuking ImmunityBio for misleading cancer drug claims. AI-driven biologics also attracted record capital, with Earendil Labs securing $787 million backed by Sanofi and Pfizer. This week's coverage offers a know before you go perspective on where capital conviction, regulatory action, and scientific innovation are converging to shape the probability of success across biotech portfolios.

BioIntel – Mar 25, 2026

Summary:
Merck announced an agreement to acquire Terns Pharmaceuticals for approximately $6.7 billion, targeting a promising leukemia treatment candidate focused on hematologic malignancies. The transaction represents the week's largest deal and underscores how major pharmaceutical companies continue to use strategic acquisitions to secure novel therapeutic assets in oncology. The acquisition enables Merck to strengthen its hematology portfolio while leveraging Terns' clinical-stage pipeline. The deal follows a broader pattern of large pharma deploying significant capital to fill pipeline gaps through targeted external innovation rather than relying solely on internal R&D.

Why it matters:
A $6.7 billion oncology acquisition signals where large pharma sees differentiated pipeline value. Tracking M&A at this scale provides a know-before-you-go signal for executives evaluating competitive positioning and capital allocation where the probability of success is increasing.

BioIntel – Mar 27, 2026

Summary: T
he FDA approved Rocket Pharma's Kresladi, a gene therapy for a rare immune disorder, based on positive outcomes in a small patient population of nine individuals. The approval represents a continued expansion of the gene therapy landscape for rare diseases and reflects the FDA's openness to evaluating therapies with limited but compelling clinical evidence in conditions with no approved alternatives. BioIntel reporting indicates the decision aligns with evolving regulatory frameworks that balance rigorous evaluation with urgent patient access needs in underserved disease areas.

Why it matters:
Gene therapy approvals in rare diseases validate accelerated regulatory pathways and signal where development strategies can align with FDA flexibility. This milestone supports strategic clarity for companies navigating orphan drug programs and increases confidence in the probability of success.

BioIntel – Mar 23, 2026

Summary:
Earendil Labs secured $787 million in funding to expand its AI-driven biologics design platform, with backing from Sanofi and Pfizer. The company has generated more than 40 programs using machine learning, predictive modeling, and biophysical datasets. Its anti-inflammatory assets have attracted a significant partnership with Sanofi. The capital will accelerate ongoing programs, enable diversification into new therapeutic targets, and support continued refinement of AI algorithms. The investment scale and pharma-partner endorsement position Earendil as a leading AI-enabled biologics platform.

Why it matters:
AI-enabled biologics design platforms augment scientific workflows and improve early-stage decision quality. Investment of this magnitude—backed by major pharma partners—signals where the probability of success is increasing across AI-driven drug development pipelines.

BioIntel – Mar 26, 2026

Summary:
Denali Therapeutics received FDA approval for Avlayah, the first therapy approved to directly address the neurological complications of Hunter syndrome, a rare genetic disorder also known as mucopolysaccharidosis type II. Existing treatments have historically focused on peripheral symptoms, leaving neurologic manifestations largely unaddressed. Avlayah represents a meaningful advance for patients with this debilitating condition and demonstrates the potential for targeted therapies to reach previously untreatable disease compartments. The approval further expands the rare disease gene therapy landscape.

Why it matters:
The first FDA-approved therapy targeting neurologic complications of Hunter syndrome validates investment in rare disease innovation where unmet need is acute. This approval reinforces how regulatory pathways for rare diseases continue to support development efficiency and increase the probability of success.

BioIntel – Mar 25, 2026

Summary:
The 16 largest pharmaceutical companies collectively invested $159 billion in R&D during 2025, a 3.6% decline from $165 billion the prior year. BioIntel reporting indicates this contraction reflects cautious capital allocation and deliberate pipeline optimization rather than a retreat from innovation. Companies are increasingly prioritizing programs with higher clinical and commercial probability of success while reducing investment in lower-confidence assets. The trend aligns with broader industry dynamics including patent expirations, pricing pressures, and a strategic shift toward external acquisitions to supplement internal discovery efforts.

Why it matters:
Declining R&D spending alongside rising M&A activity reveals how pharma is recalibrating its innovation model. Understanding this shift improves decision quality for stakeholders evaluating where capital is flowing and where the probability of success is being concentrated.