FDA Grants Fast Track Designation to RC88 in Platinum-Resistant Recurrent Ovarian Cancer

The FDA has granted a fast track designation (FTD) to RC88, a mesothelin-targeting antibody-drug conjugate (ADC) for the treatment of patients with platinum-resistant recurrent epithelial ovarian, fallopian tube, and primary peritoneal cancer, according to an announcement from RemeGen.¹

“The FDA’s FTD accelerates the development and review process of RC88, which affirms our commitment to pioneering treatments that address the urgent needs of those facing challenging disease. Moving forward, RemeGen will continue to accelerate the development of its ADC products, with the aim of bringing more and better solutions to patients globally,” Jianmin Fang, PhD, chief executive officer of RemeGen, stated in the news release.¹

Patients with aggressive, late-stage ovarian cancer have high expression of mesothelin and limited treatment options. RC88 is a selective inhibitor of mesothelin that consists of a recombinant humanized anti-mesothelin antibody linked to the microtubule inhibitor monomethyl auristatin E. The agent has high affinity for mesothelin, specifically binding to tissues that overexpress mesothelin, resulting in tumor cell death.¹

Differential expression of mesothelin in malignant tissue and normal tissue makes the protein an ideal drug target.²

In December 2023, the company received investigational new drug approval for the evaluation of RC88 in phase 2 clinical trials.²

The agent will be evaluated in an open-label, randomized, dose-optimization phase 2 study (NCT06173037) across multiple countries to determine its optimal dosage, effectiveness, and safety in patients with platinum-resistant ovarian cancer.¹

To be eligible for enrollment patients must be at least 18 years of age and have histological confirmation of platinum-resistant disease, exposure to at least 1 but no more than 3 prior lines of systemic therapy, including at least 1 type of platinum-based therapy, documented radiographic progression on or after their most recent line of anticancer therapy, an ECOG performance status of 0 or 1, life expectancy of at least 12 weeks, an archival tumor tissue sample or fresh biopsy for mesothelin testing, and adequate hematologic, liver, cardiac, and kidney function.

Notably, patients must have completed prior systemic therapy within 5 half-lives or 4 weeks before the first dose of study therapy and focal radiation at least 2 weeks before the first dose of investigational therapy.

Approximately 88 eligible patients will be enrolled, and all patients will receive 2.0 mg/kg of RC88 monotherapy on day 1 of every 3-week cycle until disease progression, unacceptable toxicity, withdrawal of consent, death, or study termination by the sponsor.

All patients will undergo tumor assessments, including radiological assessments by CT/MRI scans at screening and subsequently every 6 weeks (± 1 week) from cycle 1, day 1 for the first 48 weeks, then every 12 weeks (± 1 week) until disease progression, death, the start of new anticancer therapy, or patient withdrawal.³

All patients who discontinue RC88 will be followed for survival every 3 months (± 2 weeks) until death, lost to follow-up, withdrawal of consent for survival follow-up, or end of study.

The primary outcome measure will be overall response rate (ORR) by independent review committee. Secondary end points will include ORR by investigator, IRC- and investigator-assessed duration of response, progression-free survival, and overall survival; and pharmacokinetics, and quality of life. 

References

1. RemeGen’s RC88 obtained FDA fast track designation, heralds new hope for ovarian cancer patients. News release. RemeGen. January 12, 2024. Accessed January 12, 2024. https://www.prnewswire.com/news-releases/remegens-rc88-obtained-fda-fast-track-designation-heralds-new-hope-for-ovarian-cancer-patients-302033529.html
2. RemeGen’s pioneering RC88 receives IND approval from US FDA for platinum-resistant recurrent ovarian cancer treatment. News release. RemeGen. December 28, 2023. Accessed January 12, 2024. https://www.prnewswire.com/apac/news-releases/remegens-pioneering-rc88-receives-ind-approval-from-us-fda-for-platinum-resistant-recurrent-ovarian-cancer-treatment-302023170.html
3. RC88 in platinum-resistant recurrent epithelial ovarian cancer, fallopian tube cancer, and primary peritoneal cancer. ClinicalTrials.gov. Updated December 15, 2023. Accessed January 12, 2024. https://classic.clinicaltrials.gov/ct2/show/NCT06173037