Drug Safety-related Labeling Changes (SrLC)

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Drug Safety-related Labeling Changes (SrLC) Database

ANDA	Abbreviated New Drug Application
BLA	Biologics License Application
CDER	Center for Drug Evaluation and Research
MG	Medication Guide
NDA	New Drug Application
PCI	Patient Counseling Information
PI	Patient Information
PLR	Physician Labeling Rule
PLLR	Pregnancy and Lactation Labeling Rule
Italics	For the most part, italics indicate an FDA comment such as: Additions and/or revisions underlined These italics usually appear at the beginning of the section. In some cases, italics may be an inherent part of the label, and will most often appear in the body of the section.
Underlines	Any text that is underlined indicates text that has been added or revised. There are exceptions where underlining occurs in a section subtitle or heading. This is the case when there is just one word underlined in the body of the text.

Sections

BW	Box Warning
WP	Warnings and Precautions all in one section (PLR-format) Warnings as one section (pre-PLR format) Precautions as one section (pre-PLR format)
AR	Adverse Reactions (in pre-PLR format, this may be a subheading under precautions).
DI	Drug Interactions (in pre-PLR format, this may be a subheading under precautions).
USP	Use in Specific Populations (Inclusive on one or more of the following: Pregnancy; Lactation (PLLR- format); Nursing Mothers (pre-PLLR format); Females and Males of Reproductive Potential (PLLR format only); Pediatric Use, Geriatric Use, Renal Impairment, Hepatic Impairment, Sex, Race (these last six may be a subheading of precautions if label in pre-PLLR format.
PCI/PI/MG	Patient Counseling Information (PLR format only) - summarizes the information that a health care provider should convey to a patient (or caregiver when applicable) when a counseling discussion is taking place (e.g., a physician prescribing a drug during an office visit, a nurse providing discharge instructions at a hospital, or a pharmacist conveying information at a pharmacy). Patient Information - FDA approved patient labeling. Medication Guide - paper handouts that come with many prescription medicines. The guides address issues that are specific to particular drugs and drug classes, and they contain FDA-approved information that can help patients avoid serious adverse events.

Only NDAs and CDER regulated BLAs are included in this database. ANDAs are not included.

Applications that remain active, even if the product has been discontinued, undergo safety-related labeling changes.

TYRUKO (BLA-761322)

(NATALIZUMAB-SZTN)

Safety-related Labeling Changes Approved by FDA Center for Drug Evaluation and Research (CDER)

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10/30/2025 (SUPPL-2)

Approved Drug Label (PDF)

5 Warnings and Precautions

5.8 Hematological Abnormalities

Subsection title revised

Cases of thrombocytopenia, including immune thrombocytopenic purpura (ITP), have been reported with the use of natalizumab products in the postmarketing setting. Symptoms of thrombocytopenia may include easy bruising, abnormal bleeding, and petechiae. Delay in the diagnosis and treatment of thrombocytopenia may lead to serious and life- threatening sequelae. If thrombocytopenia is suspected, TYRUKO should be discontinued.

Cases of neonatal thrombocytopenia and anemia have been reported in newborns with in utero exposure to natalizumab products [see Use in Specific Populations (8.1)]. A CBC should be obtained in neonates with in utero exposure to TYRUKO.

6 Adverse Reactions

Additions and/or revisions underlined:

…

Hematological Abnormalities [see Warnings and Precautions (5.8)]

6.2 Immunogenicity

Additions and/or revisions underlined:

The observed incidence of anti-drug antibodies is highly dependent on the sensitivity and specificity of the assay. Differences in assay methods preclude meaningful comparisons of the incidence of anti-drug antibodies in the studies described below with the incidence of anti-drug antibodies in other studies, including those of natalizumab or of other natalizumab products.

…

17 PCI/PI/MG (Patient Counseling Information/Patient Information/Medication Guide)

PATIENT COUNSELING INFORMATION

Additions and/or revisions underlined:

…

Hematological Abnormalities

Inform patients that TYRUKO may cause a low platelet count, which can cause severe bleeding that may be life- threatening. Instruct patients to report any symptoms that may indicate thrombocytopenia, such as easy bruising, prolonged bleeding from cuts, petechiae, abnormally heavy menstrual periods, or bleeding from the nose or gums that is new. Advise patients that TYRUKO may cause low platelet or red blood cell counts in neonates exposed to TYRUKO during pregnancy [see Warnings and Precautions (5.8)].

…

MEDICATION GUIDE

Additions and/or revisions underlined:

…

What should I tell my doctor before receiving each dose of TYRUKO?

Before you receive TYRUKO, tell your doctor if you:

…

are pregnant or plan to become pregnant. TYRUKO may cause low platelets (thrombocytopenia) and low red blood cells (anemia), in your newborn baby if you take TYRUKO while you are pregnant. It is not known if TYRUKO can cause birth defects.
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