Kiadis to Restructure Months After Acquiring CytoSen Therapeutics

Seven months after acquiring CytoSen Therapeutics for its NK-cell platform, Netherlands-based Kiadis Pharma announced this morning that will now be its sole developmental focus. The company will discontinue development of its lead T-cell asset, ATIR101, halt its ongoing Phase III trial and lay off half its staff.

Now that the CytoSen NK-cell platform is under its umbrella, Kiadis said the off-the-shelf platform has the potential to make NK-cell therapy products rapidly and economically available for a broad patient population across a potentially wide range of indications. NK-cells are one of the body's first lines of immunological defense with an innate ability to rapidly and selectively destroy abnormal cells, such as cancer or virally-infected cells.

CytoSen's lead NK-cell therapy candidate, CSDT002-NK, now known as K-NKoo2, is expected to enter clinical development in 2020. A Phase I/II study is expected to begin early next year as an adjunctive treatment to the current standard-of-care haploidentical hematopoietic stem cell transplantation (HSCT) with post-transplant cyclophosphamide (PTCy). The phase I/II study was designed based on promising clinical proof-of-concept data in 25 patients that demonstrated a reduction of long-term relapse rates from 45% in a matched contemporaneous control of patients treated with PTCy, to 8% of patients treated with PTCy and K-NK002.

Also entering the clinic next year will be K-NK003, a potential treatment for patients with relapse and refractory acute myeloid leukemia. A Phase I/IIa study will be initiated in 2020 and is based on clinical proof-of-concept data that showed a 69% complete response rate, the company said. Kiadis has multiple preclinical programs evaluating its K-NK-cell therapies for the treatment of solid tumors.

Arthur Lahr, chief executive officer of Kiadis Pharma, said the company believes its NK-cell therapy platform has “broad potential as stand-alone or adjunctive treatments for patients with both liquid and solid tumors.” He said the off-the-shelf platform is based on NK-cells from unique universal donors, which have then been expanded and activated with the company’s PM21 particle technology. That has allowed for the rapid availability of the NK-cell products for patients in need, he said.

“The proof-of-concept trials for our NK pipeline programs, in which 38 patients have been treated, is very promising and was the basis for our acquisition of CytoSen Therapeutics, Inc. earlier this year. To confirm findings from these trials, we will start two Phase 1/2 clinical trials in 2020. We believe that investing in our NK platform and rapidly advancing development of our off-the-shelf and haplo donor-derived NK-cell therapies in solid and liquid tumors will bring value to patients and our investors,” Lahr said in a statement.

When the company reviewed its portfolio, Lahr said the company focused on its lead T-cell product and after significant analysis, determined that the current design of the Phase III trial would demonstrate superiority over the PTCy protocol.

“In the best interest of patients, we have therefore taken the decision to discontinue the ATIR101 study with immediate effect and are proceeding with close down activities,” Lahr added.

As a result of the new focus, Kiadis will lay off about half of its staff, a reduction in external clinical trial costs associated with the phase 3 study and a reduced company cash burn. The company ended the third quarter of 2019 with approximately €47 million in cash.