Aileron Therapeutics announced that a review of initial data from its Phase 1b chemoprotection trial of ALRN-6924 in patients with p53-mutated breast cancer showed that patients in the trial experienced severe neutropenia (Grade 4) and alopecia. The primary endpoint of the Phase 1b open-label trial, which was evaluating ALRN-6924 in patients with breast cancer receiving neoadjuvant or adjuvant treatment with docetaxel, doxorubicin, and cyclophosphamide, or “TAC” chemotherapy, was duration and incidence of severe neutropenia in cycle 1. Incidence of chemotherapy-induced alopecia (hair loss) was a secondary endpoint. Based on these findings, Aileron has decided to terminate the Phase 1b breast cancer trial and further development of ALRN-6924.

Aileron also announced that it is exploring a range of strategic alternatives to maximize shareholder value. The company has engaged Ladenburg Thalmann & Co., Inc. to act as a strategic advisor for this process. Strategic alternatives that are being evaluated may include, but are not limited to, an acquisition, a merger, a business combination, a sale of assets or other transactions.

There is no set timetable for this process and there can be no assurance that this process will result in Aileron pursuing a transaction or that any transaction, if pursued, will be completed on attractive terms. Aileron does not intend to comment further on this process unless or until its Board of Directors has approved a definitive course of action or it is determined that other disclosure is appropriate. Aileron has determined to reduce its remaining workforce from 9 to 3 full-time employees in the coming weeks. The company plans to retain the remaining employees to assist in executing the strategic alternatives review process.

ALRN-6924 is an MDM2/MDMX inhibitor that leverages Aileron's proprietary peptide drug technology. Aileron originally initiated development of ALRN-6924 as an anti-cancer agent to restore p53-dependent tumor suppression in p53 wild-type tumors, evaluating ALRN-6924 as an anti-cancer agent in 196 patients in multiple clinical trials, including a single-agent Phase 1 trial in solid tumor and lymphoma patients; a single-agent Phase 2a trial for the treatment of peripheral T-cell lymphoma; a single-agent and Ara-C-combination Phase 1/1b trial for the treatment of acute myeloid leukemia and myelodysplastic syndrome (MDS); and a Phase 2a combination trial of ALRN-6924 and palbociclib in patients with tumors harboring MDM2 amplifications. In these trials, ALRN-6924 was generally well-tolerated, with evidence of single-agent anti-tumor activity including complete and partial responses.

Aileron has also conducted three clinical trials of ALRN-6924 as a chemoprotective agent in p53-mutated small cell lung cancer, non-small cell lung cancer, and breast cancer.