Gilead Advances Oncology Portfolio With New Data From Phase 3 ASCENT Trial of Trodelvy® in Metastatic Triple Negative Breast Cancer

Trodelvy is a Trop-2-directed antibody and topoisomerase inhibitor conjugate that is indicated in the U.S. for the treatment of adult patients with mTNBC who have received at least two prior therapies for metastatic disease. Trodelvy received accelerated approval for this patient population in April 2020, based on objective response rate and duration of response results observed in a single-arm, multicenter Phase 2 study. Continued approval for this indication may be contingent upon verification and description of clinical benefit in confirmatory trials. The Trodelvy U.S. Prescribing Information has a BOXED WARNING for severe neutropenia and severe diarrhea; see below for Important Safety Information.

Based on the overall efficacy and safety results with Trodelvy in the Phase 3 ASCENT trial, Gilead has submitted a supplemental Biologics License Application (sBLA) to the U.S. Food and Drug Administration (FDA) for full approval as a treatment for adult patients with mTNBC who have received at least two prior therapies.

“These new data and analyses from the ASCENT trial continue to demonstrate the benefits of Trodelvy in a difficult-to-treat patient population and reinforce the role of Trodelvy as an important treatment option for mTNBC patients,” said Loretta M. Itri, Chief Medical Officer of Immunomedics, a wholly owned subsidiary of Gilead.

“We look forward to working with the FDA in their review of the sBLA submission for Trodelvy in mTNBC, and partnering with the agency, clinical trial investigators and participants as we build on the work of Immunomedics and continue to study Trodelvy in other cancers with unmet medical need,” said Daejin Abidoye, Senior Vice President, Head of Oncology, Gilead Sciences.

Data and analyses from the Phase 3 ASCENT trial being presented at SABCS 2020 include:

• An exploratory analysis demonstrating overall survival, objective response rate and progression-free survival with Trodelvy versus chemotherapy in brain metastases-negative mTNBC patients irrespective of Trop-2 expression levels. Trop-2 receptors are expressed on the surface of many epithelial tumor cells and linked to poor prognosis, including decreased survival. (Abstract #GS3-06)

• An exploratory analysis demonstrating tumor response, progression-free survival and overall survival with Trodelvy versus chemotherapy in a subset of mTNBC patients with stable brain metastases of limited sample size (Trodelvy, N=32; TPC, N=29). (Abstract #PD13-07)

• Additional safety data on Trodelvy in mTNBC patients with reduced uridine diphosphate-glucuronosyl transferase 1A1 (UGT1A1) activity. Patients who are homozygous for the UGT1A1*28 allele are at increased risk for neutropenia following initiation of treatment with Trodelvy. (Abstract #PS11-09)

About Triple-Negative Breast Cancer (TNBC)

TNBC is an aggressive type of breast cancer, accounting for up to 20% of all breast cancers. The disease is diagnosed more frequently in younger and premenopausal women and is highly prevalent in African American and Hispanic women. TNBC cells do not have estrogen and progesterone receptors and have limited human epidermal growth factor receptor 2 (HER2). Medicines targeting these receptors therefore are not typically effective in treating TNBC. There is currently no approved standard of care for people with previously treated metastatic TNBC.

About the ASCENT Trial

The Phase 3, international, multi-center, randomized confirmatory trial enrolled more than 500 patients with relapsed/refractory, metastatic triple-negative breast cancer who had received at least two prior therapies for metastatic disease. Patients were randomized to receive either Trodelvy or a chemotherapy chosen by the patients’ treating physicians. The primary endpoint of the study was progression-free survival. Secondary endpoints include overall survival, objective response rate, duration of response, time to onset of response, and other measures of safety and tolerability. More information about ASCENT is available at http://clinicaltrials.gov/show/NCT02574455.

About Trodelvy

Trodelvy is a Trop-2-directed antibody and topoisomerase inhibitor conjugate indicated in the U.S. for the treatment of adult patients with metastatic triple-negative breast cancer (mTNBC) who have received at least two prior therapies for metastatic disease. Trodelvy binds to the cell-surface protein Trop-2 and delivers the anti-cancer drug SN-38 to kill cancer cells.

Trodelvy received accelerated approval as a treatment for adult patients with mTNBC who have received at least two prior therapies, based on results of a single-arm, multicenter Phase 2 study. Continued approval for this indication may be contingent upon verification and description of clinical benefit in confirmatory trials.

In addition to multiple ongoing studies of Trodelvy in triple-negative breast cancer, Trodelvy is being developed as an investigational treatment for metastatic urothelial cancer, hormone receptor-positive/human epidermal growth factor receptor 2-negative metastatic breast cancer, and metastatic non-small cell lung cancer, either as a monotherapy or in combination with other agents.

Important Safety Information for Trodelvy

WARNING: NEUTROPENIA AND DIARRHEA

TRODELVY can cause severe or life-threatening neutropenia. Withhold TRODELVY for absolute neutrophil count (ANC) below 1500/mm³ on Day 1 of any cycle or ANC below 1000/mm³ on Day 8 of any cycle. Withhold TRODELVY for neutropenic fever.

Monitor blood cell counts periodically during treatment. Consider Granulocyte Colony-Stimulating Factor (G-CSF) for secondary prophylaxis. Initiate anti-infective treatment in patients with febrile neutropenia without delay.

• Dose modifications may be required due to neutropenia. Febrile neutropenia occurred in 6% (24/408) of patients treated with TRODELVY, including 8% (9/108) of patients with mTNBC after at least 2 prior therapies. Less than 1% (1/408) of patients had febrile neutropenia leading to permanent discontinuation. The incidence of Grade 1-4 neutropenia was 64% in patients with mTNBC (n=108). In all patients treated with TRODELVY (n=408), the incidence of Grade 1-4 neutropenia was 54%; Grade 4 neutropenia occurred in 13%. Less than 1% (2/408) of patients permanently discontinued treatment due to neutropenia.

Severe diarrhea may occur. Monitor patients with diarrhea and give fluid and electrolytes as needed. Administer atropine, if not contraindicated, for early diarrhea of any severity. At the onset of late diarrhea, evaluate for infectious causes and, if negative, promptly initiate loperamide. If severe diarrhea occurs, withhold TRODELVY until resolved to ≤ Grade 1 and reduce subsequent doses.

• Diarrhea occurred in 63% (68/108) of patients with mTNBC and 62% (254/408) of all patients treated with TRODELVY. In each population, events of Grade 3-4 occurred in 9% (10/108) of mTNBC patients and 9% (36/408) of all patients treated with TRODELVY. Four out of 408 patients (<1%) discontinued treatment because of diarrhea. Neutropenic colitis was observed in 2% (2/108) of patients in the mTNBC cohort and 1% of all patients treated with TRODELVY.

Contraindications: Severe hypersensitivity reaction to TRODELVY.

Hypersensitivity

• TRODELVY can cause severe and life-threatening hypersensitivity, including anaphylactic reactions. Hypersensitivity reactions occurred within 24 hours of dosing in 37% (151/408) and Grade 3-4 hypersensitivity occurred in 1% (6/408) of all patients treated with TRODELVY (n=408). The incidence of hypersensitivity reactions leading to permanent discontinuation of TRODELVY was 1% (3/408).
• Pre-infusion medication for patients receiving TRODELVY is recommended. Observe patients closely for infusion-related reactions during each TRODELVY infusion and for at least 30 minutes after completion of each infusion. Medication to treat such reactions, as well as emergency equipment, should be available for immediate use.

Nausea and Vomiting

• TRODELVY is emetogenic. Nausea occurred in 69% (74/108) of patients with mTNBC and 69% (281/408) of all patients treated with TRODELVY. Grade 3 nausea occurred in 6% (7/108) and 5% (22/408) of these populations, respectively. Vomiting occurred in 49% (53/108) of patients with mTNBC and 45% (183/408) of all patients treated with TRODELVY. Grade 3 vomiting occurred in 6% (7/108) and 4% (16/408) of these patients, respectively.
• Premedicate with a 2- or 3-drug combination regimen (e.g., dexamethasone with either a 5-HT3 receptor antagonist or an NK-1 receptor antagonist as well as other drugs as indicated) for prevention of chemotherapy-induced nausea and vomiting (CINV).
• Withhold TRODELVY doses for Grade 3 nausea or Grade 3-4 vomiting at the time of scheduled treatment administration and resume with additional supportive measures when resolved to Grade ≤ 1. Additional antiemetics and other supportive measures may also be employed as clinically indicated. All patients should be given take-home medications with clear instructions for prevention and treatment of nausea and vomiting.

Use in Patients with Reduced UGT1A1 Activity

• Individuals who are homozygous for the uridine diphosphate-glucuronosyl transferase 1A1 (UGT1A1)*28 allele are at increased risk for neutropenia and may be at increased risk for other adverse events following initiation of TRODELVY treatment. Closely monitor patients with reduced UGT1A1 activity for severe neutropenia. The appropriate dose for patients who are homozygous for UGT1A1*28 is not known and should be considered based on individual patient tolerance to treatment.
• In 84% (343/408) of patients who received TRODELVY (up to 10 mg/kg on Days 1 and 8 of a 21-day cycle) and had retrospective UGT1A1 genotype results available, the incidence of Grade 4 neutropenia was 26% (10/39) in patients homozygous for the UGT1A1*28 allele, 13% (20/155) in patients heterozygous for the UGT1A1*28 allele, and 11% (16/149) in patients homozygous for the wild-type allele.

Embryo-Fetal Toxicity

• TRODELVY contains a genotoxic component and can cause teratogenicity and/or embryo-fetal lethality when administered to a pregnant woman. Advise pregnant women and females of reproductive potential of the potential risk to a fetus.
• Advise females of reproductive potential to use effective contraception during treatment with TRODELVY and for 6 months following the last dose. Advise male patients with female partners of reproductive potential to use effective contraception during treatment with TRODELVY and for 3 months after the last dose.

Lactation

Because of the potential for serious adverse reactions in a breastfed child, advise women not to breastfeed during treatment and for 1 month after the last dose of TRODELVY.

Adverse Reactions

Most common adverse reactions (incidence >25%) in patients with mTNBC are nausea (69%), neutropenia (64%), diarrhea (63%), fatigue (57%), anemia (52%), vomiting (49%), alopecia (38%), constipation (34%), rash (31%), decreased appetite (30%), abdominal pain (26%), and respiratory infection (26%).

Please see full Prescribing Information, including BOXED WARNING.

About Gilead Sciences

Gilead Sciences, Inc. is a research-based biopharmaceutical company that discovers, develops and commercializes innovative medicines in areas of unmet medical need. The company strives to transform and simplify care for people with life-threatening illnesses around the world. Gilead has operations in more than 35 countries worldwide, with headquarters in Foster City, California. For more information on Gilead Sciences, please visit the company’s website at www.gilead.com.

Gilead Forward-Looking Statement

This press release includes forward-looking statements, within the meaning of the Private Securities Litigation Reform Act of 1995 that are subject to risks, uncertainties and other factors, including the possibility of unfavorable results from ongoing and additional clinical studies involving Trodelvy, and the possibility that Gilead may be unable to initiate and complete future studies involving Trodelvy in the anticipated timelines or at all. All statements other than statements of historical fact are statements that could be deemed forward-looking statements. These risks, uncertainties and other factors could cause actual results to differ materially from those referred to in the forward-looking statements. The reader is cautioned not to rely on these forward-looking statements. These and other risks are described in detail in Gilead’s Quarterly Report on Form 10-Q for the quarter ended September 30, 2020, as filed with the U.S. Securities and Exchange Commission. All forward-looking statements are based on information currently available to Gilead, and Gilead assumes no obligation to update any such forward-looking statements.

U.S. Prescribing Information for TRODELVY, including BOXED WARNING, is available at www.gilead.com.

TRODELVY, Gilead and the Gilead logo are trademarks of Gilead Sciences, Inc., or its related companies.

For more information about Gilead, please visit the company’s website at www.gilead.com, follow Gilead on Twitter (@Gilead Sciences) or call Gilead Public Affairs at 1-800-GILEAD-5 or 1-650-574-3000.

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