On April 8, 2022 C4 Therapeutics, Inc. (C4T) (Nasdaq: CCCC), a clinical-stage biopharmaceutical company dedicated to advancing targeted protein degradation science to develop a new generation of small-molecule medicines and transform how disease is treated, reported that data from Cohort A of its ongoing Phase 1/2 clinical trial of CFT7455, a novel degrader targeting IKZF1/3 for the treatment of multiple myeloma (MM) and non-Hodgkin’s lymphomas (NHL) (Press release, C4 Therapeutics, APR 8, 2022, View Source [SID1234611676]). The data will be presented at the American Association for Cancer Research (AACR) (Free AACR Whitepaper) Annual Meeting on Tuesday, April 12, 2022, at 9 AM CT by Sagar Lonial, M.D., FACP.

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"The early clinical data from the ongoing Phase 1/2 trial demonstrates that CFT7455’s differentiated pre-clinical profile, including enhanced PK and increased activity, has translated to the clinical setting," said Dr. Sagar Lonial, professor and chair, department of hematology and medical oncology, Winship Cancer Institute, Emory University. "Single agent CFT7455 has demonstrated preliminary evidence of clinical activity in a population of highly refractory and heavily pre-treated multiple myeloma patients. We continue to enroll patients in the ongoing clinical trial with the goal of providing a new treatment option for myeloma and lymphoma patients."

"We are encouraged by the early clinical observations and the potential of CFT7455 to be a next-generation therapy to treat multiple myeloma and non-Hodgkin’s lymphomas," said Adam Crystal, M.D., Ph.D., chief medical officer of C4 Therapeutics. "We believe this initial data highlights the ability of our TORPEDO platform to develop highly potent and selective degraders that have the potential to demonstrate deep and durable degradation of intended targets in the clinical setting. We will leverage the unique properties of CFT7455 to optimize its schedule and increase the therapeutic index as we progress to a recommended Phase 2 dose."

CFT7455 Phase 1/2 Clinical Trial
C4T designed CFT7455 to be highly potent and selective against its intended targets, IKZF1/3. The Phase 1/2 trial is designed to primarily investigate safety, tolerability, and anti-tumor activity. Secondary and exploratory objectives are to characterize the PK and pharmacodynamic profile of CFT7455. The Phase 1 portion of the study explores CFT7455 as a single agent in patients with relapsed or refractory (RR) MM and NHL, as well as in combination with dexamethasone in patients with RRMM. Following identification of a recommended dose(s) and schedule(s), the Phase 2 portion of the trial is expected to expand to the following four investigational arms: (1) in RRMM, single agent CFT7455; (2) in RRMM, CFT7455 combined with dexamethasone; (3) in peripheral T-cell lymphoma, single agent CFT7455; and (4) in mantle cell lymphoma, single agent CFT7455.

Cohort A, the first cohort in the clinical trial, explored CFT7455 as a single agent and enrolled five patients with MM. All patients in Cohort A were highly refractory and heavily pre-treated, having received a median of five prior lines of therapy (range of 4-14), including both lenalidomide and pomalidomide. The starting dose in the trial was 50 μg and all patients in Cohort A received single agent CFT7455 for 21 days of the 28-day treatment cycle. The data cut-off date was January 14, 2022. At the time of this data cut-off, two patients remained on therapy; however, these patients have since discontinued treatment.

Summary of Data from Cohort A:

Safety

Four patients received single agent CFT7455 at the starting dose of 50 μg per day. Two of these patients were dose reduced to 25 μg per day due to neutropenia, a known on-target toxicity associated with IKZF1/3 degraders.
The fifth patient enrolled at a starting dose of 25 μg per day based on the recommendation of the safety review committee.
Two dose-limiting toxicities (DLTs) were observed at the 50 μg per day starting dose, both consistent with on-target activity:
Grade 4 neutropenia lasting more than 5 days
A delay (more than 7 days) in initiating treatment in Cycle 2, in the setting of persistent Grade 3 neutropenia
No patient experiencing neutropenia had a concurrent infection or fever.
There were no serious adverse events reported and no adverse events resulted in death or treatment discontinuation.
Pharmacokinetics and Pharmacodynamics

CFT7455 was rapidly absorbed, with a plasma half-life of approximately two days. Accumulation of drug was observed up to four-fold by day 15 and achieved exposures at 50 μg that were equivalent to predicted highly active exposures based on pre-clinical studies.
CFT7455 demonstrated deep and durable degradation of IKZF1/3, as quantified by mass spectrometry, throughout Cycle 1.
Efficacy

Responsiveness was measured based on International Myeloma Working Group (IMWG) criteria.
Three patients had best observed reductions in the difference of serum free light chain (dFLC) ranging from 41 percent to 78 percent. One patient had an increase of 56 percent in dFLC.
The patient who achieved a 78 percent reduction in dFLC did not achieve a partial response under IMWG criteria due to the presence of measurable plasmacytomas, which were assessed as stable.
Three patients had a best response of stable disease. Two patients had a best response of progressive disease.
Next Steps for CFT7455
C4T has completed modeling of the Cohort A data and believes alternative dosing regimens are expected to increase the therapeutic index by allowing time for adequate neutrophil maturation during the days off drug, with limited impact on efficacy. Patients are enrolling in Cohort B1, exploring CFT7455 as a monotherapy for RRMM, and Cohort C, exploring CFT7455 as a monotherapy for NHL. Cohorts B1 and C have a starting dose of 25 μg per day at an alternative dosing schedule. Each cohort will proceed with dose finding in parallel, with the goal of achieving a recommended Phase 2 dose in each of MM and NHL.

Investor Webcast Information
C4T will host an investor webcast today, Friday, April 8, 2022, at 2 PM ET, with Sagar Lonial, M.D., FACP to discuss the CFT7455 clinical data being presented at AACR (Free AACR Whitepaper). To access the call, please dial 866-374-5140 or 404-400-0571 and provide the conference ID: 66856580. The webcast can be also accessed under "Events & Presentations" in the Investors section of the company’s website at www.c4therapeutics.com. A replay of the webcast will be available on C4T’s website for 30 days following the event.