Gilead's PrEP Engine Hits $4B Run Rate as M&A Charges Mask Underlying Strength

Gilead's second-quarter 2026 results were a study in contrasts: the base business delivered its strongest Q2 growth in three years, led by an HIV franchise now running at a $4B annual PrEP business run rate, while the bottom line absorbed an $11.1B acquired IPR&D hit from the closure of Arcellx, Tubulis, and Ouro Medicines. The stock, up 5% over the last 90 days and sitting just 6% below its February peak, suggests investors are looking through the accounting noise to the operational momentum.

A Milestone Quarter for HIV Prevention

Daniel O'Day opened the call framing the quarter as one of "commercial excellence," noting base business sales were up 10% year-over-year. The engine was HIV, where sales rose 12% YoY. The standout was PrEP: “Our PrEP business doubled year-over-year in the second quarter and for the first time, exceeded $1 billion in quarterly sales.” — Johanna Mercier, Chief Commercial Officer · 2026-08-04 Johanna Mercier added that the U.S. PrEP market grew 14%, with Gilead outpacing it by over 100%.

Yeztugo, the twice-yearly injectable, has quickly become the leading long-acting option for new PrEP starts, with a persistency rate above 70%—well above available alternatives. Guidance for full-year HIV growth was raised to 9-10% from 8%, and the company reaffirmed its ~$1B Yeztugo sales target. This is a dramatic step up from the prior quarter's call, where the emphasis was still on launch execution: “We are really excited about what we are seeing with the strong performance in the first quarter, and that is really across all of the launch metrics that you were referring to.” — Johanna Mercier, Chief Commercial Officer · 2026-05-07 The trajectory from launch to market leader in under four quarters is a company-unique signal, not sector boilerplate.

Oncology and Pipeline Momentum

Beyond HIV, Trodelvy grew 26% YoY to $457M, approaching a $2B run rate, and the back-to-back first-line approvals in metastatic TNBC expand its addressable population. The newly closed Tubulis acquisition brought GS 8824, with encouraging Phase I ovarian cancer data—61% confirmed ORR and a median PFS of 11 months in platinum-resistant disease. Dietmar Berger highlighted the platform potential: "We feel that combining our breakthrough capsid inhibitor with really today's standard of care backbone... could be a preferred option." Anito-cel, with full ownership now via Arcellx, is set for a December PDUFA, with launch preparation already underway.

The three acquisitions—Arcellx, Tubulis, and Ouro Medicines—were the biggest pipeline additions in the company's history, but they came at a price. CFO Andrew Dickinson explained the accounting:

Excluding the $11.1 billion in acquired IP R&D expenses associated with the 3 acquisitions, our second quarter operating margin was approximately 49%.

The Financial Rubik's Cube

The IPR&D charge drove non-GAAP EPS to -$6.75, though illustrative EPS excluding the deals came in at $2.27, up ~13% YoY. Full-year guidance now has base business sales growing 6-7% and total product sales of $30.1-$30.4B, though Veklury was cut to ~$300M due to lower COVID hospitalizations. The balance sheet has shifted to net debt of about $15.8B as of Q1—a direct consequence of the M&A spree—but interest coverage remains a healthy 10.8x. Investors should watch whether the company can sustain this growth while integrating three platforms without additional large deals. Management explicitly said they won't pursue further sizable M&A this year.

The strength of the underlying operations is visible in the fundamentals, even before the deals distorted Q2. Q1 operating margin stood at 37.2% on a GAAP basis, and the call suggests Q2 would have been ~49% excluding IPR&D—firmly top-quartile among peers. The key question for the back half is whether the BIC/LEN approval (expected August 27) and anito-cel launch can keep the momentum, especially as the HIV treatment market saw some slowing due to ACA changes.

In summary, Gilead has crossed a pivotal inflection point: the PrEP franchise is now a durable growth engine, the oncology pipeline is diversified across ADCs, cell therapy, and bispecifics, and the financial drag from acquisitions is largely non-recurring. The next catalysts—BIC/LEN, anito-cel, and the weekly oral HIV program—will determine whether the stock's current premium is justified.