eFFECTOR Initiates Dosing in Phase 2 Trial of Tomivosertib (eFT508) in Advanced Castrate-Resistant Prostate Cancer (CRPC)

Solana Beach, California, UNITED STATES

SAN DIEGO, Dec. 11, 2018 (GLOBE NEWSWIRE) -- eFFECTOR Therapeutics, Inc., (eFFECTOR), a leader in the development of selective translation regulators (STRs) for the treatment of cancer, announced today that it has dosed the first patient in a Phase 2 trial of tomivosertib (eFT508) in men with advanced castrate-resistant prostate cancer (CRPC) who experienced progression on a secondary hormonal agent. Tomivosertib is a highly selective inhibitor of MNK 1 and MNK 2 (MNK 1/2), kinases which promote tumor growth and immune evasion. 

“Tomivosertib is highly active in preclinical models of prostate cancer, including castrate-resistant xenografts and explant models derived directly from patients’ tumor samples,” said Steve Worland, Ph.D., president and chief executive officer of eFFECTOR. “Tomivosertib may therefore provide a new way to address treatment-resistant prostate cancers, including those which are driven by variant forms of the androgen receptor.”

In completed clinical studies to date in solid tumors and lymphomas, tomivosertib was shown to be safe and well tolerated at the recommended Phase 2 dose that demonstrates clinical activity, including partial responses and prolonged stable disease in patients with advanced cancers that have failed to respond to, or relapsed after, multiple prior treatments.

About Advanced Castration-resistant Prostate Cancer (CRPC)
Treatment for early prostate cancer with androgen deprivation therapy frequently leads to a drug resistant disease state termed castration-resistant prostate cancer (CRPC), in which tumors continue to grow despite treatments that reduce levels of male hormones. CRPC is associated with low survival rates, poor quality of life and limited treatment options. Advanced CRPC reflects further tumor progression after additional treatment with secondary hormonal agents. Advanced CRPC is frequently driven by variant forms of the androgen receptor (AR) that can continue to signal and drive tumor growth despite therapy. By inhibiting the MNK pathway, tomivosertib may be able to block signaling and tumor growth in men with advanced CRPC.

About the Phase 2 Study of Tomivosertib in Advanced CRPC

In the Phase 2 study [NCT03690141], tomivosertib will be administered orally, twice a day, as monotherapy to men with CRPC. The primary endpoint of this study is anti-tumor response assessed by decline in PSA levels or objective response by iRECIST (and adaptation of RECIST used for agents with an immunomodulatory mechanism). Secondary endpoints include progression-free survival, overall survival and safety and tolerability of tomivosertib in this patient population.  eFFECTOR plans to enroll approximately 30 men in the study at ten clinical sites located in United States. The company expects to report interim data from this study in the first half of 2019.

About Tomivosertib (eFT508)

Tomivosertib is eFFECTOR’s wholly-owned, highly selective translation regulator that inhibits MNK1 and MNK2 (MNK1/2) acting at the level of mRNA translation. The oral small molecule drug candidate promotes anti-tumor immune activity by selective down regulation of several immune checkpoint receptors and specific immunosuppressive cytokines. Tomivosertib also has direct action in certain tumor cells, including prostate cancer.

Tomivosertib in being evaluated in multiple ongoing Phase 2 clinical studies in cancers that may respond to MNK inhibition. Patients are actively being recruited into a study of tomivosertib in castration resistant prostate cancer [NCT03690141]. Tomivosertib is also being evaluated as an add-on when patients are experiencing insufficient response to an FDA-approved checkpoint inhibitor [NCT03616834] and in combination with the PD-L1 checkpoint inhibitor avelumab in relapsed or refractory micro satellite stable colorectal cancer (MSS CRC) [NCT03258398]. As part of a clinical collaboration with Merck and Co., tomivosertib will also be tested in combination with pembrolizumab in triple negative breast cancer.

Please visit www.clinicaltrials.gov for further information on ongoing clinical studies of tomivosertib.

About eFFECTOR Therapeutics

eFFECTOR Therapeutics is a clinical-stage biopharmaceutical company at the forefront of an emerging class of therapeutics known as selective translation regulators or STRs. By acting on key biological mechanisms responsible for tumor growth and immune suppression, STRs represent a promising small molecule approach for fighting cancer. eFFECTOR’s most advanced program, tomivosertib (eFT508), is currently in multiple Phase 2 clinical trials for the treatment of several types of cancer, both as an immune modulator and as an agent that acts directly on tumor cells. Through its expertise with STRs, eFFECTOR has entered into clinical collaborations with a strategic alliance between Pfizer and Merck KGaA to study tomivosertib in combination with avelumab and separately with Merck & Co to evaluate tomivosertib in combination with KEYTRUDA. Additionally, the company has an emerging pipeline of promising STR programs targeting well-known oncogenes and intractable targets. eFFECTOR maintains global rights to all of its development programs. For more information visit www.effector.com.


Amy Conrad
Juniper Point

Heidi Chokeir, Ph.D.
Canale Communications