FDA Approves Talon Therapeutics, Inc.'s Marqibo to Treat Rare Type of Leukemia

SOUTH SAN FRANCISCO, Calif., Aug. 9, 2012 (GLOBE NEWSWIRE) -- Talon Therapeutics today announced Marqibo® (vinCRIStine sulfate LIPOSOME injection) received accelerated approval from the U.S. Food and Drug Administration (FDA) for the treatment of adult patients with Philadelphia chromosome negative (Ph-) acute lymphoblastic leukemia (ALL) in second or greater relapse or whose disease has progressed following two or more anti-leukemia therapies. This indication is based on overall response rate. Clinical benefit such as improvement in overall survival has not been verified. Marqibo is administered at a dose of 2.25 mg/m2 intravenously over 1 hour once every 7 days. Marqibo has different dosage recommendations than non-liposomal vincristine sulfate.

"We are delighted that Marqibo will be available to a patient population with an underserved hematologic malignancy," stated Steven R. Deitcher MD, President, Chief Executive Officer and Board Member of Talon Therapeutics. "This represents a transformational event for Talon and fulfillment of our most important corporate goal, to date."

About Marqibo®

Marqibo is a novel, sphingomyelin/cholesterol liposome-encapsulated, formulation of vincristine sulfate. Vincristine, a microtubule inhibitor, is FDA-approved for ALL and Non-Hodgkin's Lymphoma (NHL) and is widely used in combination regimens for treatment for a variety of adult and pediatric hematologic and solid tumor malignancies. The Optisome™ nanoparticle encapsulation technology, utilized by Talon, has been shown to provide prolonged circulation of vincristine in the blood.

Marqibo has received orphan drug designation for the treatment of ALL from the FDA and from the European Medicines Agency (EMA). Talon intends to submit a Marketing Authorization Application to the EMA in 2013.

Please see important safety information below and the full prescribing information for Marqibo at www.marqibo.com.

Indication and usage

Marqibo is a liposomal vinca alkaloid indicated for the treatment of adult patients with Philadelphia chromosome-negative (Ph-) acute lymphoblastic leukemia (ALL) in second or greater relapse or whose disease has progresses following two or more anti-leukemia therapies. This indication is based on overall response rate. Clinical benefit such as improvement in overall survival has not been verified.

Important safety information

CONTRAINDICATIONS

Marqibo is contraindicated in patients with demyelinating conditions including Charcot-Marie-Tooth syndrome

Marqibo is contraindicated in patients with hypersensitivity to vincristine sulfate or any of the other components of Marqibo (vinCRIStine sulfate LIPOSOME injection

Marqibo is contraindicated for intrathecal administration

WARNING

See full prescribing information for complete boxed warning.

For Intravenous Use Only – Fatal if Given by Other Routes

Death has occurred with intrathecal use

Marqibo (vinCRIStine sulfate LIPOSOME injection) has different dosage recommendations than vinCRIStine sulfate injection. Verify drug name and dose prior to preparation and administration to avoid overdosage.

Warnings and Precautions

For Intravenous Use Only

For Intravenous use only. Fatal if given by other routes.

Extravasation Tissue Injury

Only administer through a secure and free-flowing venous access line. If extravasation is suspected, discontinue infusion immediately and consider local treatment measures.

Neurologic Toxicity

Sensory and motor neuropathies are common and are cumulative. Monitor patients for symptoms of neuropathy, such as hypoesthesia, hyperesthesia, paresthesia, hyporeflexia, areflexia, neuralgia, jaw pain, decreased vibratory sense, cranial neuropathy, ileus, burning sensation, arthralgia, myalgia, muscle spasm, or weakness, both before and during treatment. Orthostatic hypotension may occur. The risk of neurologic toxicity is greater if Marqibo is administered to patients with preexisting neuromuscular disorders or when other drugs with risk of neurologic toxicity are being given. In the studies of relapsed and/or refractory adult ALL patients, Grade = 3 neuropathy events occurred in 32.5% of patients. Worsening neuropathy requires dose delay, reduction, or discontinuation of Marqibo.

Myelosuppression

Monitor complete blood counts prior to each dose of Marqibo. If Grade 3 or 4 neutropenia, thrombocytopenia, or anemia develops, consider Marqibo dose modification or reduction as well as supportive care measures.

Tumor Lysis Syndrome

Tumor lysis syndrome (TLS) may occur in patients with ALL receiving Marqibo. Anticipate, monitor for, and manage.

Constipation and Bowel Obstruction

Ileus, bowel obstruction, and colonic pseudo-obstruction have occurred. Marqibo can cause constipation. Institute a prophylactic bowel regimen to mitigate potential constipation, bowel obstruction, and/or paralytic ileus, considering adequate dietary fiber intake, hydration, and routine use of stool softeners, such as docusate. Additional treatments, such as senna, bisacodyl, milk of magnesia, magnesium citrate, and lactulose may be considered.

Fatigue

Marqibo can cause severe fatigue. Marqibo dose delay, reduction, or discontinuation may be necessary.

Hepatic Toxicity

Fatal liver toxicity and elevated levels of aspartate aminotransferase have occurred. Elevated levels of aspartate aminotransferase of Grade =3 occurred in 6-11% of patients in clinical trials. Monitor hepatic function tests. Reduce or interrupt Marqibo for hepatic toxicity.

Embryofetal Toxicity

Marqibo can cause fetal harm when administered to a pregnant woman. Vincristine sulfate liposome injection was teratogenic or caused embryo-fetal death in animals. Women of childbearing potential should avoid becoming pregnant while being treated with Marqibo. There are no adequate and well-controlled studies of Marqibo in pregnant women and there were no reports of pregnancy in any of the clinical studies in the Marqibo clinical development program. If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to a fetus [see Use in Specific Populations].

Adverse Reactions

The most common adverse reactions (>30%) were constipation (57%), nausea (52%), pyrexia (43%), fatigue (41%), peripheral neuropathy (39%), febrile neutropenia (38%), diarrhea (37%), anemia (34%), decreased appetite (33%), and insomnia (32%).

The most commonly reported SAEs included febrile neutropenia (20.5%), pyrexia (13.3%), hypotension (7.2%), respiratory distress (6.0%), and cardiac arrest (6.0%).

Twenty-eight percent of patients experienced adverse reactions leading to treatment discontinuation. The most common adverse reactions that caused treatment discontinuation were peripheral neuropathy (10%), leukemia-related (7%), and tumor lysis syndrome (2%).

Deaths occurred in 23% of patients in study 1. The non-leukemia related causes of deaths were brain infarct (1), intracerebral hemorrhage (2), liver failure (1), multi-system organ failure (2), pneumonia and septic shock (3), respiratory failure (4), pulmonary hemorrhage (1), and sudden cardiac death (1).

Drug Interactions

No formal drug interaction studies have been conducted with Marqibo. Marqibo is expected to interact with drugs known to interact with non-liposomal vincristine sulfate.

Simultaneous oral or intravenous administration of phenytoin and antineoplastic chemotherapy combinations that included non-liposomal vincristine sulfate has been reported to reduce blood levels of phenytoin and to increase seizure activity.

CYP3A Interactions

Vincristine sulfate, the active agent in Marqibo, is a substrate for cytochrome P450 3A isozymes (CYP3A); therefore, the concomitant use of strong CYP3A inhibitors should be avoided (e.g., ketoconazole, itraconazole, voriconazole, posaconazole, clarithromycin, atazanavir, indinavir, nefazodone, nelfinavir, ritonavir, saquinavir, telithromycin). Similarly, the concomitant use of strong CYP3A inducers should be avoided (e.g., dexamethasone, phenytoin, carbamazepine, rifampin, rifabutin, rifapentine, phenobarbital, St. John's Wort).

P-glycoprotein Interactions

Vincristine sulfate, the active agent in Marqibo, is also a substrate for P-glycoprotein (P-gp). The effect of concomitant use of potent P-gp inhibitors or inducers has not been investigated; it is likely that these agents will alter the pharmacokinetics or pharmacodynamics of Marqibo. Therefore the concomitant use of potent P-gp inhibitors or inducers should be avoided.

Use in Specific Populations

Pregnancy

Pregnancy Category D [see Warnings and Precautions]

Based on its mechanism of action and findings from animal studies, Marqibo can cause fetal harm when administered to pregnant women.

If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to a fetus. In an embryofetal developmental study, pregnant rats were administered vincristine sulfate liposome injection intravenously during the period of organogenesis at vincristine sulfate doses of 0.022 to 0.09 mg/kg/day. Drug-related adverse effects included fetal malformations (skeletal and visceral), decreases in fetal weights, increased numbers of early resorptions and post-implantation losses, and decreased maternal body weights Malformations were observed at doses = 0.044 mg/kg/day in animals at systemic exposures approximately 20-40% of those reported in patients at the recommended dose.

Nursing Mothers

It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants, a decision should be made whether to discontinue nursing or discontinue the drug taking into account the importance of the drug to the mother.

Pediatric Use

The safety and effectiveness of Marqibo in pediatric patients have not been established.

Geriatric Use

Safety and effectiveness in elderly individuals have not been established. In general, dose selection for an elderly patient should be cautious, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.

Renal Impairment

The influence of renal impairment on the safety, efficacy, and pharmacokinetics of Marqibo has not been evaluated.

Hepatic Impairment

Non-liposomal vincristine sulfate is excreted primarily by the liver. The influence of severe hepatic impairment on the safety and efficacy of Marqibo has not been evaluated. The pharmacokinetics of Marqibo was evaluated in patients with moderate hepatic dysfunction (Child-Pugh B) secondary to melanoma liver metastases. The dose-adjusted maximum plasma concentration (Cmax) and area under the concentration-time curve (AUC) of Marqibo in patients with moderate hepatic impairment was comparable to the Cmax and AUC of patients with ALL who had otherwise normal hepatic function.

Conference Call Information

Date: August 10, 2012

Time: 12:00pm EDT, 9:00am PDT

Dial-in (US and Canada): (877) 681-1326

Dial-in (International): (708) 290-1158

Webcast: www.talontx.com

An archived version of the webcast will also be available via the company's website following the call.

About Talon Therapeutics

Talon Therapeutics, Inc. is a biopharmaceutical company dedicated to seizing upon medical opportunities, efficiently and expertly leading product candidates through clinical development, and transferring value to patients, patient care providers, shareholders, corporate partners, and employees.

In addition to Marqibo, the Company has additional pipeline opportunities some of which, like Marqibo, have the potential to improve delivery and enhance the therapeutic benefits of well characterized, proven chemotherapies and enable high potency dosing without increased toxicity.

Additional information on Talon Therapeutics can be found at www.talontx.com.

The Talon Therapeutics, Inc. logo is available at http://www.globenewswire.com/newsroom/prs/?pkgid=3290

Forward-Looking Statement

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These statements are often, but not always, made through the use of words or phrases such as "anticipates," "expects," "plans," "believes," "intends," and similar words or phrases. These forward-looking statements include without limitation, statements regarding the potential of Marqibo to become a new treatment option or a new standard of care for the treatment of adult relapsed ALL, the timing of Talon's planned regulatory filings with the EMA, and other statements that are other than statements of historical fact. Such statements involve risks and uncertainties that could cause Talon's actual results to differ materially from the anticipated results and expectations expressed in these forward-looking statements. These statements are based on current expectations, forecasts and assumptions that are subject to risks and uncertainties, which could cause actual outcomes and results to differ materially from these statements. Among other things, there can be no assurances that Marqibo will be accepted in the marketplace, that Talon will be able to develop, either alone or with a partner, adequate marketing and distribution capabilities, that Marqibo will be eligible for reimbursement from third party payors, Talon's dependence on third party manufacturers, that any of Talon's future clinical and regulatory development efforts relating to Marqibo will be successful, including the ongoing Phase 3 confirmatory trial; that the results of the ongoing and planned clinical trials of Marqibo support Talon's claims or beliefs concerning Marqibo's safety and effectiveness will be sufficient to support label expansion; that Talon will be able to secure the additional capital necessary to fund its product development and commercialization programs, including Marqibo, to completion. Additional risks are described in the company's Annual Report on Form 10-K for the year ended December 31, 2011 and Form 10-Q for the period ending March 31, 2012. Talon assumes no obligation to update these statements, except as required by law.

CONTACT: Talon Therapeutics, Inc.

Investor & Media Contacts:

Investor Relations Team

(650) 588-6641

investor.relations@talontx.com

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