CytomX Therapeutics is shifting its focus to preclinical and early clinical studies, emphasizing alliances and slashing its workforce by about 40% to extend cash flow to 2025.
On Wednesday, CytomX Therapeutics announced it is refocusing its efforts and resources on its early clinical pipeline. In what it called a “strategic realignment,” the company plans to cull approximately 40% of its staff in an effort to extend its cash runway into 2025.
In particular, CytomX stated it is emphasizing “future business development and new alliance formation” as part of its corporate strategy. The company is already partnered with pharma giants AbbVie, Bristol Myers Squibb, Astellas and Amgen, and the press release stated it will continue to prioritize these partnerships moving forward.
Sean McCarthy, D.Phil., CEO and chairman at CytomX Therapeutics, expressed his condolences about the decision to cull staff and thanked employees for their work thus far.
“In the context of the challenging current investment climate for biotechnology, we are making a series of changes to ensure CytomX remains well positioned for the future...This difficult decision to restructure CytomX regrettably leads to the departure of many valued team members who have been dedicated to our vision and mission and whose contributions have been critical to the Company’s success to date.”
This comes one week after the company discontinued enrollment in two out of three arms of its Phase II study of praluzatamab ravtansine in patients with triple-negative breast cancer (TNBC) after those studies failed to meet the protocol-defined futility boundary.
Arm B, which evaluated either 6 mg/kg or 7 mg/kg of the drug in patients with inoperable, locally advanced or metastatic TNBC and Arm C, which looked into using 6 mg/kg of the drug with 1200 mg of pacmilimab, will be halted.
Only Arm A, which evaluated praluzatamab ravtansine 7 mg/kg as monotherapy, will be considered, with future activity focused on lowering the dose to 6 mg/kg due to some observed toxicities. This trial demonstrated a clinical benefit rate of 40%, and the patients showed a median progression-free survival of 2.6 months.
Praluzatamab ravtansine is a DM4-conjugated, conditionally activated antibody-drug conjugate (ADC) that targets CD166, whose expression is linked with various cancers.
“We’re disappointed to have not seen more activity in triple-negative breast cancer but our work in Arms B and C has given important insight into the safety profile of praluzatamab ravtansine at 6 mg/kg,” Amy Peterson, M.D., president and chief operating officer of CytomX, said in the company’s web presentation.
As per the May 13 data cutoff in Arm A, 47 patients unselected for CD166 expression with advanced HR+/HER2-non-amplified breast cancer were evaluable for the primary endpoint of confirmed objective response rate by central radiology review, logging an ORR of 15%.
However, the Arm B cohort logged an ORR of less than 10%, which was the main reason for the halt that affected both arms B and C. In addition, 33% of the participants had to discontinue treatment, with 15% experiencing grade 3+ ocular toxicities and 10% experiencing neuropathic toxicities. Arms A and Arm B recorded similar toxicity issues, but only Arm A showed some promise in terms of ORR.
“While we are encouraged by the emerging safety profile of 6 mg/kg, we do not plan to further advance this program alone given current financial market conditions and will be seeking a partnership. This strategy will allow us to focus our resources on other areas of our clinical and preclinical pipeline,” McCarthy said.
“When we selected the DM4 payload for this program, we did so with the expectation that payload-related toxicity would be observed. The antibody masking component of praluzatamab ravtansine is designed to minimize toxicities. If we take a step back and look at the totality of our achievements with [the drug], we can say that our masking technology has allowed us to target CD166. However, the optimization related to payload toxicities has proven harder than expected and more work is required. We believe this is best achieved with a partner,” he added.
