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# Comments on Draft PD Cancer Treatment Guidance
- URL: https://www.fdaweb.com/comments-on-draft-pd-cancer-treatment-guidance/
- Published: 2021-10-26T12:00:00.000Z
- Updated: 2026-09-14T17:20:19.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5150440

Genentech says it commends FDA for leveraging scientific and regulatory experience to develop guidance for sponsors on how PK-based criteria can be used to support registration of alternative dosing regimens beyond those studied in dedicated clinical trials. Responding to an agency draft guidance, *Pharmacokinetic-Based Criteria for Supporting Alternative Dosing Regimens of Programmed Cell Death Receptor-1 (PD-1) or Programmed Cell Death Ligand 1 (PD-L1) Blocking Antibodies for Treatment of Patients with Cancer*, Genentech [says](ttps://downloads.regulations.gov/FDA-2021-D-0691-0008/attachment%5F1.pdf) it believes that the implementation of PK-based and other MIDD (model-informed drug development) approaches are critical to efficiently develop patient-centric treatment options that minimize risk and burden to patients while preserving the necessary data for doctors and patients to make informed decisions that fit the needs of individual patients.

The letter urges FDA to expand the guidance to other antibody-based therapies. “While we recognize that PD-1/L1 blocking antibodies are relatively well understood,” the company says, “we note that there are many antibody-based therapies with wide therapeutic windows for which the proposed PK-based criteria is highly relevant….”

In its comment, AbbVie [says](https://downloads.regulations.gov/FDA-2021-D-0691-0006/attachment%5F1.pdf?ref=fdaweb.com) the guidance can apply to other class agents with similar antagonist activity and mechanism of action.

Janssen [provides](https://downloads.regulations.gov/FDA-2021-D-0691-0005/attachment%5F1.pdf?ref=fdaweb.com) general comments on combination regimens, alternative routes of administration, and reference dosing regimen, and specific line-by-line comments.

The GlaxoSmithKline response [suggests](https://downloads.regulations.gov/FDA-2021-D-0691-0003/attachment%5F1.pdf?ref=fdaweb.com) adding clarifying text on two issues and gives line-by-line comments.

Finally, Pfizer [submits](https://downloads.regulations.gov/FDA-2021-D-0691-0004/attachment%5F1.pdf?ref=fdaweb.com) specific line-by-line comments.