For patients with newly diagnosed, high-risk diffuse large B-cell lymphoma (DLBCL), adding avadomide to standard therapy may reduce the likelihood of treatment failure, based on phase 1 results.
The regimen was well tolerated and had a complete response rate of 79%, reported lead author Neha Mehta-Shah, MD, of Washington University, St. Louis, who presented findings as part of the American Society of Clinical Oncology virtual scientific program.
Newly diagnosed DLBCL “remains a clinical challenge,” Dr. Mehta-Shah said, noting a treatment failure rate of 30%-50% for standard rituximab with cyclophosphamide, doxorubicin, vincristine, and prednisone every 21 days (R-CHOP-21), and worse outcomes among patients with high-risk disease.
In an effort to boost efficacy, the investigators turned to avadomide, a cereblon E3 ligase modulator, which previously demonstrated a complete response rate of 11% when used as monotherapy for patients with relapsed or refractory DLBCL.
The present phase 1 data included 35 adults with newly diagnosed DLBCL who had measurable lesions of at least 2.0 cm and International Prognostic Indices (IPI) between 3-5. Specifically, 51% of patients had an IPI of 3, while 49% had an IPI of 4-5.
All patients received standard R-CHOP with pegfilgrastim (to stimulate white blood cell growth), plus escalating doses of oral avadomide from 1-3 mg. Treatment was delivered, when tolerated, for up to six 21-day cycles. Depending on dose level, avadomide was given during either 2 or 3 out of 3 weeks. During treatment weeks, avadomide was given on 5 of 7 days.
The primary objectives were safety, tolerability, and complete response rate. Secondary objectives included biomarkers and additional efficacy measures, while exploratory analyses were also conducted to assess pharmacokinetics and pharmacodynamics.
Out of 34 patients evaluable for efficacy, the complete response rate was 79% and the objective response rate was 88%. After a median follow-up of 10 months, the 1-year progression-free survival rate was 80%.
“The combination showed promising efficacy,” Dr. Mehta-Shah said.
The regimen was also well tolerated and demonstrated an “acceptable safety profile consistent with either therapy alone,” Dr. Mehta-Shah added.
Most patients (91%) completed all six cycles of therapy. Median relative total dose intensities were 99% and 95% for avadomide and R-CHOP-21, respectively. Approximately two out of three patients (66%) required dose interruptions of avadomide, and 9% required dose reductions because of adverse events.
Dose-limiting toxicities occurred in six patients, including sepsis, febrile neutropenia caused by skin infections, febrile neutropenia with hypotension, febrile neutropenia, pneumonia, and neutropenia with bacterial hepatic infection. Based on these findings, the recommended phase 2 dose of avadomide was determined to be 3 mg given during 2 out of 3 weeks.
About 74% of patients had grade 3-4 treatment-emergent adverse events, the most common of which were neutropenia (54%), anemia (20%), leukopenia (20%), lymphopenia (14%), hypophosphatemia (14%), and febrile neutropenia (11%).
During the second cycle of therapy, one patient died because of concurrent pneumonia. After completion of therapy, two patients developed cardiac failure, and data gathered after each cycle showed that five patients had developed elevated levels of troponin or brain natriuretic peptide.
Flow cytometry showed that avadomide had proimmunomodulatory effects, including expansion of memory T-cell populations and enhanced proliferation of T cells and NK cells. The magnitude of this latter increase was greater than that observed in previous studies involving R-CHOP and durvalumab, Dr. Mehta-Shah noted.
“We look forward to following up on this data regarding the progression-free survival over a longer period of time,” Dr. Mehta-Shah said. “The results of this trial indicate that further evaluation of cereblon-modulating compounds combined with immunochemotherapy for patients with previously untreated diffuse large B-cell lymphoma is worthy of further exploration.”
Invited discussant Edward Yeh, MD, of the University of Missouri–Columbia, called cereblon modulators such as avadomide and thalidomide a “very exciting class of anticancer therapy.”
In a virtual presentation, Dr. Yeh noted that cereblon modulators have several advantages, including “good absorption, distribution, metabolism, [and] elimination,” plus relatively low susceptibility to mutation-directed drug resistance.
Despite some drawbacks, including difficulty to design and synthesize, Dr. Yeh suggested that this drug class may play a bigger role over time.
“We’re expecting more cancer therapy to come to fruition through the utilization of this posttranslational, protein-modification pathway,” he concluded.
The study was funded by Celgene. The investigators disclosed additional relationships with Kyowa Hakko Kirin, AstraZeneca, Roche, and others.
SOURCE: Mehta-Shah N et al. ASCO 2020, .