Home / FDA News / FDA Grants Priority Review to Daiichi Sankyo’s CSF1R Inhibitor for Treatment of Patients with Tenosynovial Giant Cell Tumor

FDA Grants Priority Review to Daiichi Sankyo’s CSF1R Inhibitor for Treatment of Patients with Tenosynovial Giant Cell Tumor

TOKYO and MUNICH and BASKING RIDGE, N.J., Feb. 5, 2019 /PRNewswire/ — Daiichi Sankyo Company, Limited (hereafter, Daiichi Sankyo) announced that the U.S. Food and Drug Administration (FDA) has accepted a New Drug Application (NDA) and granted Priority Review for pexidartinib for the treatment of adult patients with symptomatic tenosynovial giant cell tumor (TGCT), which is associated with severe morbidity or functional limitations, and which is not amenable to improvement with surgery. TGCT, also referred to as pigmented villonodular synovitis (PVNS) or giant cell tumor of the tendon sheath (GCT-TS), is a non-malignant tumor of the joint or tendon sheath, which can be locally aggressive and debilitating in some patients. There are no currently approved systemic therapies for TGCT.

A Priority Review designation is granted by the FDA to drugs that, if approved, would be significant improvements in the safety or effectiveness of the treatment, diagnosis, or prevention of serious conditions when compared to standard applications. Under Priority Review, the FDA aims to take action on an application within six months, as compared to ten months under standard review. The FDA has designated August 3, 2019 as the PDUFA Action date for this application.  

On January 31, 2019, the American Society of Clinical Oncology (ASCO) recognized “Progress in Treating Rare Cancers” as the “Advance of the Year,” and selected pexidartinib as one of five significant advancements in rare disease treatment, calling it the first promising investigational therapy for TGCT.

The NDA is based on results of the pivotal phase 3 ENLIVEN study of oral pexidartinib, the first placebo-controlled study of a systemic investigational therapy in patients with TGCT. Results of the phase 3 ENLIVEN study were presented during an oral presentation at the 2018 American Society of Clinical Oncology (ASCO) Annual Meeting.

“We are pleased to announce that the FDA has accepted our application for pexidartinib with Priority Review designation, potentially bringing a treatment option to patients for whom there is no approved therapy,” said Dale Shuster, Ph.D., Executive Director, Global Oncology R&D, Daiichi Sankyo. “Current treatment options for TGCT are largely limited to surgery, but for some patients the disease is debilitating and not amenable to improvement with surgery. We are committed to working with the FDA to potentially bring pexidartinib to carefully-selected patients as soon as possible.”

“We are excited about the first-in-class potential of pexidartinib, another targeted therapy discovered by Plexxikon,” said Gideon Bollag, Ph.D., Chief Executive Officer of Plexxikon Inc., Daiichi Sankyo’s small molecule structure-guided R&D center in Berkeley, CA and a member of the Daiichi Sankyo Group. “Our drug discovery process uses structural data and a specialized scaffold-like screening library to identify and optimize novel drug candidates.”

ENLIVEN is a pivotal, double-blind, randomized, global multi-center phase 3 study that evaluated pexidartinib in patients with symptomatic advanced TGCT for whom surgical removal of the tumor would be associated with potentially worsening functional limitation or severe morbidity. The first part of the study, the double-blind phase, enrolled 120 patients who were randomized (1:1) to receive either pexidartinib or placebo at 1000 mg/d for 2 weeks followed by 800 mg/d for 22 weeks in order to evaluate the efficacy and safety of pexidartinib versus placebo. The primary endpoint of the study was the percentage of patients achieving a complete or partial response after 24 weeks of treatment (Week 25), as assessed with centrally-read MRI scans using RECIST 1.1 criteria. Key secondary endpoints included range of motion, response by tumor volume score, PROMIS physical function, stiffness and measures of pain reduction.

The ENLIVEN study met its primary endpoint of overall response rate. In the ENLIVEN study, hepatic toxicities were more frequent with pexidartinib versus placebo (AST or ALT ≥3X ULN: 33 percent, total bilirubin ≥2X ULN: 5 percent, N=61). Eight patients discontinued pexidartinib due to hepatic adverse events (AEs); four were serious nonfatal AEs with increased bilirubin, one lasting ~7 months. In non-TGCT development studies using pexidartinib, two severe liver toxicity cases (one required liver transplant, one was associated with death) were observed.

About TGCT (PVNS/GCT-TS)

Tenosynovial giant cell tumor (TGCT), also referred to as pigmented villonodular synovitis (PVNS) or giant cell tumor of the tendon sheath (GCT-TS), is a rare, usually non-malignant tumor that can be locally aggressive. TGCT affects the synovium-lined joints, bursae, and tendon sheaths, resulting in swelling, pain, stiffness and reduced mobility in the affected joint or limb.1,2 Patients are commonly diagnosed in their 20s to 50s, and depending on the type of TGCT, women can be up to twice as likely to develop a tumor as men.3,4

While the exact incidence of TGCT is not known, it is estimated that the incidence of TGCT is 11 to 50 cases per million, based on studies from three countries.5-7  TGCT is subcategorized into two types: localized, which is more common and accounts for 90 percent of cases, and diffuse, which accounts for 10 percent of cases.6,7 Recurrence rates for localized TGCT are estimated to be up to 15 percent following complete resection.2,8,9,10 Diffuse TGCT recurrence rates are estimated to be about 20 percent to 50 percent following complete resection.4,8,11

Primary treatment of TGCT includes surgery to remove the tumor. However, in patients with a recurrent, difficult to treat, or diffuse form where the tumor can wrap around bone, tendons, ligaments and other parts of the joint, it is more difficult to remove or might not be amenable to improvement with surgery. Additional surgeries for more severe cases can lead to significant joint damage, debilitating functional impairments, and reduced quality of life and amputation may be considered.3,12,13

About Pexidartinib 

Pexidartinib is an investigational, novel, oral small molecule that potently inhibits CSF1R (colony stimulating factor-1 receptor), which is a primary growth driver of abnormal cells in the synovium that cause TGCT. Pexidartinib also inhibits c-kit and FLT3-ITD. Pexidartinib was discovered by Plexxikon Inc., the small molecule structure-guided R&D center of Daiichi Sankyo.

In addition to Priority Review designation, pexidartinib has been granted Breakthrough Therapy designation for the treatment of patients with pigmented villonodular synovitis (PVNS) or giant cell tumor of tendon sheath (GCT-TS), where surgical resection may result in potentially worsening functional limitation or severe morbidity, and Orphan Drug designation for PVNS/GCT-TS by the U.S. Food and Drug Administration (FDA). Pexidartinib also has received Orphan Drug designation from the European Commission for the treatment of TGCT.

Pexidartinib is an investigational compound that has not been approved for any indication in any country. Safety and efficacy have not been established.

About Daiichi Sankyo Cancer Enterprise

The mission of Daiichi Sankyo Cancer Enterprise is to leverage our world-class, innovative science and push beyond traditional thinking to create meaningful treatments for patients with cancer. We are dedicated to transforming science into value for patients, and this sense of obligation informs everything we do. Anchored by three pillars including our investigational Antibody Drug Conjugate Franchise, Acute Myeloid Leukemia Franchise and Breakthrough Science, we aim to deliver seven distinct new molecular entities over eight years during 2018 to 2025. Our powerful research engines include two laboratories for biologic/immuno-oncology and small molecules in Japan, and Plexxikon Inc., our small molecule structure-guided R&D center in Berkeley, CA. Compounds in pivotal stage development include:

[fam-] trastuzumab deruxtecan, an antibody drug conjugate (ADC) for HER2 expressing breast, gastric and other cancers; quizartinib, an oral selective FLT3 inhibitor, for newly-diagnosed and relapsed/refractory FLT3-ITD acute myeloid leukemia (AML); and pexidartinib, an oral CSF1R inhibitor, for tenosynovial giant cell tumor (TGCT). For more information, please visit: www.DSCancerEnterprise.com.

About Daiichi Sankyo

Daiichi Sankyo Group is dedicated to the creation and supply of innovative pharmaceutical products to address diversified, unmet medical needs of patients in both mature and emerging markets. With over 100 years of scientific expertise and a presence in more than 20 countries, Daiichi Sankyo and its 15,000 employees around the world draw upon a rich legacy of innovation and a robust pipeline of promising new medicines to help people. In addition to a strong portfolio of medicines for hypertension and thrombotic disorders, under the Group’s 2025 Vision to become a “Global Pharma Innovator with Competitive Advantage in Oncology,” Daiichi Sankyo research and development is primarily focused on bringing forth novel therapies in oncology, including immuno-oncology, with additional focus on new horizon areas, such as pain management, neurodegenerative diseases, heart and kidney diseases, and other rare diseases. For more information, please visit: www.daiichisankyo.com. Daiichi Sankyo, Inc., headquartered in Basking Ridge, New Jersey, is a member of the Daiichi Sankyo Group. For more information on Daiichi Sankyo, Inc., please visit: www.dsi.com.

References:

  1. de Saint Aubain, et al. WHO. 2013;100-103.
  2. Rao AS, et al. J Bone Joint Surg AM. 1984;66(1):76-94.
  3. Verspoor FGM, et al. Future Oncol. 2013;10:1515-1531.
  4. Ravi V, et al. Curr Opin Oncol. 2011;23:361-366.
  5. Myers BW, et al. Medicine (Baltimore). 1980;59(3):223-238.
  6. Mastboom MJL., et al. Acta Orthopaedica. 2017;88(6):688-694.
  7. Ehrenstein V, et al. J Rheumatol. 2017;44(10):1476-1483.
  8. Gouin F, Noailles T. Orthop Traumatol Surg Res. 2017;103(1S):S91-S97.
  9. Palmerini E, Staals EL, Maki RG, et al. Eur J Cancer. 2015;51(2):210-217.
  10. Dines JS, et al. Arthroscopy. 2007;23(9):930-937.
  11. Xie G-P, et al. PLOS One. 2015;10(3):e0121451.
  12. Verspoor FGM, et al. Rheumatol. 2014;53(11):2063-2070.
  13. Brahmi M, et al. Curr Treat Options Oncol. 2016;17(2):10.

In the U.S., ZERBAXA is currently indicated for the treatment of adult patients with cUTI, including pyelonephritis, caused by certain susceptible Gram-negative microorganisms, and is also indicated, in combination with metronidazole, for the treatment of adult patients with cIAI caused by certain susceptible Gram-negative and Gram-positive microorganisms.

Corresponding applications for both medicines have been filed with the European Medicines Agency (EMA) and are currently under review.

“There is a major unmet need for new treatment options to address the growing danger of serious and potentially life-threatening infections caused by Gram-negative bacteria,” said Dr. Nicholas Kartsonis, senior vice president, head of clinical research for infectious diseases and vaccines, Merck Research Laboratories. “In a space where there are currently very few treatment options, these filings underscore Merck’s ongoing commitment to delivering new antibacterial agents to healthcare practitioners and patients.”

The IMI/REL (MK-7655A) NDA is based on the results of the pivotal Phase 3 RESTORE-IMI 1 trial, which were presented at the 28th European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) meeting in Madrid, Spain, in April 2018. The ZERBAXA sNDA is based on the pivotal Phase 3 ASPECT-NP trial in adults with ventilated hospital-acquired bacterial pneumonia or ventilator-associated bacterial pneumonia. Merck plans to present results from the ASPECT-NP study at a future scientific conference.

About imipenem, cilastatin and relebactam

Relebactam is an investigational, intravenous, class A and C beta-lactamase inhibitor currently being evaluated in combination with imipenem/cilastatin for the treatment of certain Gram-negative bacterial infections. The FDA has designated the combination of relebactam with imipenem/cilastatin for intravenous use as a Qualified Infectious Disease Product (QIDP) with Fast Track status for the treatment of complicated urinary tract infections (cUTI), complicated intra-abdominal infections (cIAI) and hospital-acquired bacterial pneumonia/ventilator-associated bacterial pneumonia (HABP/VABP).

About ZERBAXA (ceftolozane and tazobactam)

ZERBAXA is an antibacterial combination product for intravenous infusion consisting of the cephalosporin antibacterial drug ceftolozane sulfate and the beta-lactamase inhibitor tazobactam sodium.

ZERBAXA 1.5g (ceftolozane 1g and tazobactam 0.5g) is approved in the United States and is indicated in adult patients for the treatment of complicated urinary tract infections (cUTI), including pyelonephritis, caused by the following Gram-negative microorganisms: Escherichia coliKlebsiella pneumoniaeProteus mirabilis, and Pseudomonas aeruginosa. ZERBAXA used in combination with metronidazole is indicated in adult patients for the treatment of complicated intra-abdominal infections (cIAI) caused by the following Gram-negative and Gram-positive microorganisms: Enterobacter cloacaeEscherichia coliKlebsiella oxytocaKlebsiella pneumoniaeProteus mirabilisPseudomonas aeruginosaBacteroides fragilisStreptococcus anginosusStreptococcus constellatus, and Streptococcus salivarius.

To reduce the development of drug-resistant bacteria and maintain the effectiveness of ZERBAXA and other antibacterial drugs, ZERBAXA should be used only to treat infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

Important Safety Information about ZERBAXA (ceftolozane and tazobactam)

Patients with renal impairment: Decreased efficacy of ZERBAXA has been observed in patients with baseline creatinine clearance (CrCl) of 30 to ≤50 mL/min. In a clinical trial, patients with cIAIs with CrCl >50 mL/min had a clinical cure rate of 85.2% when treated with ZERBAXA (ceftolozane and tazobactam) plus metronidazole vs. 87.9% when treated with meropenem. In the same trial, patients with CrCl 30 to ≤50 mL/min had a clinical cure rate of 47.8% when treated with ZERBAXA plus metronidazole vs. 69.2% when treated with meropenem. A similar trend was also seen in the cUTI trial. Monitor CrCl at least daily in patients with changing renal function and adjust the dose of ZERBAXA accordingly.

Hypersensitivity: ZERBAXA is contraindicated in patients with known serious hypersensitivity to ceftolozane/tazobactam, piperacillin/tazobactam, or other members of the beta-lactam class. Serious and occasionally fatal hypersensitivity (anaphylactic) reactions have been reported in patients receiving beta-lactam antibacterials. Before initiating therapy with ZERBAXA, make careful inquiry about previous hypersensitivity reactions to cephalosporins, penicillins, or other beta-lactams. If an anaphylactic reaction to ZERBAXA occurs, discontinue use and institute appropriate therapy.

Clostridium difficile–associated diarrhea (CDAD), ranging from mild diarrhea to fatal colitis, has been reported with nearly all systemic antibacterial agents, including ZERBAXA. Careful medical history is necessary because CDAD has been reported to occur more than two months after the administration of antibacterial agents. If CDAD is confirmed, antibacterial use not directed against C. difficile should be discontinued, if possible.

Development of drug-resistant bacteria: Prescribing ZERBAXA (ceftolozane and tazobactam) in the absence of a proven or strongly suspected bacterial infection is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria.

Adverse reactions: The most common adverse reactions occurring in ≥5% of patients were headache (5.8%) in the cUTI trial, and nausea (7.9%), diarrhea (6.2%) and pyrexia (5.6%) in the cIAI trial.

Merck’s commitment to infectious diseases

For more than 100 years, Merck has contributed to the discovery and development of novel medicines and vaccines to combat infectious diseases. In addition to a combined portfolio of vaccines and antibacterial, antiviral and antifungal medicines, Merck has multiple programs that span discovery through late-stage development. To learn more about Merck’s infectious diseases pipeline, visit www.merck.com.

About Merck

For more than a century, Merck, a leading global biopharmaceutical company known as MSD outside of the United States and Canada, has been inventing for life, bringing forward medicines and vaccines for many of the world’s most challenging diseases. Through our prescription medicines, vaccines, biologic therapies and animal health products, we work with customers and operate in more than 140 countries to deliver innovative health solutions. We also demonstrate our commitment to increasing access to health care through far-reaching policies, programs and partnerships. Today, Merck continues to be at the forefront of research to advance the prevention and treatment of diseases that threaten people and communities around the world – including cancer, cardio-metabolic diseases, emerging animal diseases, Alzheimer’s disease and infectious diseases including HIV and Ebola. For more information, visit www.merck.com and connect with us on TwitterFacebookInstagramYouTube and LinkedIn.

Forward-Looking Statement of Merck & Co., Inc., Kenilworth, N.J., USA

This news release of Merck & Co., Inc., Kenilworth, N.J., USA (the “company”) includes “forward-looking statements” within the meaning of the safe harbor provisions of the U.S. Private Securities Litigation Reform Act of 1995. These statements are based upon the current beliefs and expectations of the company’s management and are subject to significant risks and uncertainties. There can be no guarantees with respect to pipeline products that the products will receive the necessary regulatory approvals or that they will prove to be commercially successful. If underlying assumptions prove inaccurate or risks or uncertainties materialize, actual results may differ materially from those set forth in the forward-looking statements.

Risks and uncertainties include but are not limited to, general industry conditions and competition; general economic factors, including interest rate and currency exchange rate fluctuations; the impact of pharmaceutical industry regulation and health care legislation in the United States and internationally; global trends toward health care cost containment; technological advances, new products and patents attained by competitors; challenges inherent in new product development, including obtaining regulatory approval; the company’s ability to accurately predict future market conditions; manufacturing difficulties or delays; financial instability of international economies and sovereign risk; dependence on the effectiveness of the company’s patents and other protections for innovative products; and the exposure to litigation, including patent litigation, and/or regulatory actions.

The company undertakes no obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise. Additional factors that could cause results to differ materially from those described in the forward-looking statements can be found in the company’s 2017 Annual Report on Form 10-K and the company’s other filings with the Securities and Exchange Commission (SEC) available at the SEC’s Internet site (www.sec.gov).

Please see Prescribing Information for ZERBAXA (ceftolozane and tazobactam) at http://www.merck.com/product/usa/pi_circulars/z/zerbaxa/zerbaxa_pi.pdf

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