First-in-human phase I study of SY-5609, an oral, potent, and selective noncovalent CDK7 inhibitor, in adult patients with select advanced solid tumors

TPS3662

Background: SY-5609 is an oral, noncovalent, highly selective and potent inhibitor of cyclin-dependent kinase 7 (CDK7), a key regulator of 2 biological processes that play critical roles in driving tumor development: transcription and cell cycle control. Evaluation of SY-5609 as a single agent in PDX models from a range of solid tumors, including breast, ovarian, lung and colorectal tumors, revealed robust antitumor activity including complete regressions, and activity in models known to be resistant to standard of care therapy. Models with genetic alterations in RB pathway genes demonstrated deep ( > 90% TGI) and sustained SY-5609-induced tumor regressions following treatment discontinuation, in contrast to models without genetic alteration in RB pathway genes, suggesting that tumor cells with aberrant cell-cycle control may be particularly sensitive to SY-5609 treatment. The study is designed to evaluate the safety, tolerability, and maximum tolerated dose (MTD) of SY-5609, to characterize the pharmacokinetic (PK), pharmacodynamic (PD), and preliminary antitumor activity of SY-5609, and to explore candidate biomarkers predictive of response to SY-5609. Methods: This is a multi-center, open-label Phase 1 trial expected to enroll approximately 60 adult patients with select advanced solid tumors for which standard treatment is no longer effective. The dose escalation phase of the trial is open to adult patients with ovarian, breast, colorectal, or lung cancer, and patients with any solid tumor histology with molecular evidence of deregulated RB cell cycle control. SY-5609 is being administered orally once daily, for each 4-week cycle. Initially, patients will be enrolled into single-patient accelerated titration cohorts; subsequent cohorts will transition to a 3 + 3 design. Following completion of DLT evaluation at a given dose level, additional patients may be enrolled at that dose to further characterize safety, PK, PD, and early clinical activity. Data from this trial will support dose selection for planned evaluations of antitumor activity of SY-5609 as a single agent and in combination. Clinical trial information: NCT04247126 .

Brentuximab Vedotin with Chemotherapy for Stage III or IV Hodgkin's Lymphoma

BACKGROUND

Brentuximab vedotin is an anti-CD30 antibody-drug conjugate that has been approved for relapsed and refractory Hodgkin's lymphoma.

METHODS

We conducted an open-label, multicenter, randomized phase 3 trial involving patients with previously untreated stage III or IV classic Hodgkin's lymphoma, in which 664 were assigned to receive brentuximab vedotin, doxorubicin, vinblastine, and dacarbazine (A+AVD) and 670 were assigned to receive doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD). The primary end point was modified progression-free survival (the time to progression, death, or noncomplete response and use of subsequent anticancer therapy) as adjudicated by an independent review committee. The key secondary end point was overall survival.

RESULTS

At a median follow-up of 24.6 months, 2-year modified progression-free survival rates in the A+AVD and ABVD groups were 82.1% (95% confidence interval [CI], 78.8 to 85.0) and 77.2% (95% CI, 73.7 to 80.4), respectively, a difference of 4.9 percentage points (hazard ratio for an event of progression, death, or modified progression, 0.77; 95% CI, 0.60 to 0.98; P=0.04). There were 28 deaths with A+AVD and 39 with ABVD (hazard ratio for interim overall survival, 0.73 [95% CI, 0.45 to 1.18]; P=0.20) [corrected]. All secondary efficacy end points trended in favor of A+AVD. Neutropenia occurred in 58% of the patients receiving A+AVD and in 45% of those receiving ABVD; in the A+AVD group, the rate of febrile neutropenia was lower among the 83 patients who received primary prophylaxis with granulocyte colony-stimulating factor than among those who did not (11% vs. 21%). Peripheral neuropathy occurred in 67% of patients in the A+AVD group and in 43% of patients in the ABVD group; 67% of patients in the A+AVD group who had peripheral neuropathy had resolution or improvement at the last follow-up visit. Pulmonary toxicity of grade 3 or higher was reported in less than 1% of patients receiving A+AVD and in 3% of those receiving ABVD. Among the deaths that occurred during treatment, 7 of 9 in the A+AVD group were associated with neutropenia and 11 of 13 in the ABVD group were associated with pulmonary-related toxicity.

CONCLUSIONS

A+AVD had superior efficacy to ABVD in the treatment of patients with advanced-stage Hodgkin's lymphoma, with a 4.9 percentage-point lower combined risk of progression, death, or noncomplete response and use of subsequent anticancer therapy at 2 years. (Funded by Millennium Pharmaceuticals and Seattle Genetics; ECHELON-1 ClinicalTrials.gov number, NCT01712490 ; EudraCT number, 2011-005450-60 .).