FDA Draft Guidance Spells Out Dose Escalation And Expansion Expectations For Early-Phase Solid Tumor Trials

By Elizabeth Urbanek, Executive Editor

The FDA has issued draft guidance describing how it expects sponsors to design first-in-human and other early-phase protocols for investigational oncology drugs and biologics in solid tumors. The recommendations cover eligibility, dose escalation, expansion cohorts, and dose optimization, which together shape how much investigational product a study needs and in what form.

The draft, Early-Phase IND Protocol Recommendations for Solid Tumors, is dated November 2026 and supports the U.S. Department of Health and Human Services' (HHS) Operation TrialBlazer. Comments are due Jan. 11, 2027, under docket FDA-2026-D-13432. The guidance does not cover hematologic malignancies.

On dose escalation, the FDA says maximum dose increments generally should not exceed 100% for small molecules and antibody-drug conjugates (ADCs), or a half-log for most other biologics. Smaller steps, such as 50% or modified Fibonacci increments, may be warranted after defined toxicity signals. Single-patient accelerated titration cohorts should move to at least three patients after any Grade 2 or higher adverse event, and intra-patient escalation should stop at the highest dose level already cleared.

For expansion cohorts, the statistical analysis plan should justify a maximum sample size and include stopping rules. Sponsors without enough safety data at submission may limit the protocol to dose escalation and add expansion cohorts later by amendment. When activity emerges in a specific tumor type, the FDA prefers a new IND over expanding that cohort beyond 40 patients under the early-phase IND.

The draft also says the recommended Phase 2 dose should rest on multiple dose levels rather than the maximum tolerated dose alone. For autologous cell and gene therapy products, patients should not begin lymphodepletion until it is known that the product is available.

What This Means For Clinical Supply

Early-phase supply plans are often built around one strength and a fixed number of cohorts. This draft puts several design expectations in writing that could change those assumptions before the first batch is made.

Dose granularity is the clearest example. If a protocol must be able to drop to 50% increments after a toxicity signal, the investigational medicinal product (IMP) has to support those intermediate doses through additional strengths, different vial fills, or validated pharmacy preparation. Each route adds chemistry, manufacturing, and controls (CMC) work, stability data, or site burden. A program that made a single strength for speed may find its inventory cannot deliver the escalation scheme the protocol now calls for.

Cohort structure affects demand as well. Expansion cohorts added by amendment, randomized dose optimization cohorts, and tumor-specific work moved to a new IND could each turn one forecast into a series of step changes. Teams would need to weigh manufacturing ahead for cohorts that may never open against the lead time of making material later.

The interactive response technology (IRT) system is part of the picture. Dose-level logic, the cap on intra-patient escalation, and the switch from single-patient to three-patient cohorts all have to be configured and tested. A new IND for a tumor-specific study may also mean a new protocol build.

For autologous cell and gene therapies, holding lymphodepletion until product availability is known makes manufacturing release status a direct input to the clinical schedule. That requires close coordination among the manufacturing site, the logistics provider, and investigator sites.

For supply teams supporting first-in-human oncology studies, the operational question is whether their initial drug product presentations can deliver every dose level the protocol may eventually require.

The Supply Question

Can early-phase oncology programs build in enough dose flexibility without overinvesting in strengths they may never use?

Related Clinical Supply Leader Editorials:

• The Hidden Work Between Protocol And Execution: Translating Requirements Into Supply Strategy
• Three Months Too Late: How Late Decisions Create Clinical Supply Challenges
• What Happens When The Clinical Forecast Changes?

About The Editor:

Elizabeth Urbanek is the Executive Editor for Clinical Supply Leader, where she works with clinical trial supply and logistics professionals across pharma and biotech to bring real-world perspectives, operational challenges, trends, scientific insights and regulatory strategy to the field.

Before joining life sciences media, Elizabeth spent more than 15 years in broadcast, digital and live-event storytelling, helping highly technical teams communicate complex ideas with clarity and impact. She brings that same approach to clinical supply, creating editorial space for experts to share what is happening across clinical trial operations.

Elizabeth is passionate about connecting people and ideas, identifying emerging themes and showcasing work that can move the clinical supply field forward.