On September 14, 2024 Bicycle Therapeutics plc (NASDAQ: BCYC), a pharmaceutical company pioneering a new and differentiated class of therapeutics based on its proprietary bicyclic peptide (Bicycle) technology, reported updated Phase 1/2 clinical results for Bicycle Toxin Conjugate (BTC) zelenectide pevedotin (formerly BT8009) in metastatic urothelial cancer (mUC); BTC molecule BT5528 in advanced solid tumors, such as mUC and ovarian; and Bicycle Tumor-Targeted Immune Cell Agonist (Bicycle TICA) BT7480 in advanced solid tumors (Press release, Bicycle Therapeutics, SEP 14, 2024, View Source [SID1234646566]). The company also shared an analysis of peripheral neuropathy, a key adverse event of interest associated with monomethyl auristatin E (MMAE)-based drug conjugates, in patients treated with BTC molecules. These data will be presented during a poster session at the European Society for Medical Oncology (ESMO) (Free ESMO Whitepaper) Congress 2024 in Barcelona today.
Schedule your 30 min Free 1stOncology Demo!
Discover why more than 1,500 members use 1stOncology™ to excel in:
Early/Late Stage Pipeline Development - Target Scouting - Clinical Biomarkers - Indication Selection & Expansion - BD&L Contacts - Conference Reports - Combinatorial Drug Settings - Companion Diagnostics - Drug Repositioning - First-in-class Analysis - Competitive Analysis - Deals & Licensing
Schedule Your 30 min Free Demo!
"We are pleased that the data presented at ESMO (Free ESMO Whitepaper) continue to support the promising response and differentiated safety profiles of our Bicycle molecules. Importantly, our lead investigational therapy zelenectide pevedotin continues to demonstrate an overall response rate that is in line with other drug conjugates used to treat metastatic urothelial cancer, but with a marked improvement in tolerability. Overall, we believe the data continue to demonstrate the potential of our Bicycle technology platform to create differentiated medicines designed to help patients not only to live longer but also to live well," said Kevin Lee, Ph.D., CEO of Bicycle Therapeutics. "These clinical data are just the first set of updates that we have guided to delivering this year. In the coming months, we look forward to sharing initial imaging data from our growing radiopharmaceutical pipeline and additional data for zelenectide pevedotin in bladder, breast and lung cancer."
ESMO 2024 Data Highlights
Zelenectide pevedotin is a BTC molecule targeting Nectin-4, a well-validated tumor antigen, designed to overcome the significant toxicity associated with other drug conjugate approaches. Updated results from the ongoing Phase 1/2 Duravelo-1 trial evaluating 5 mg/m2 weekly of zelenectide pevedotin monotherapy in 45 mUC patients who had not previously been treated with enfortumab vedotin showed:
Among 38 efficacy-evaluable patients, a 45% overall response rate (ORR), including 1 confirmed complete response and 16 partial responses (13 confirmed). Stable disease was maintained in 9 patients, and 12 patients experienced progressive disease.
A median duration of response of 11.1 months among the 14 patients with confirmed responses.
An emerging differentiated safety profile, particularly around adverse events of interest such as peripheral neuropathy, skin reactions and eye disorders. Notably, there were no Grade ≥3 treatment-related adverse events (TRAEs) of peripheral neuropathy (any kind), skin reactions or eye disorders, and patients with pre-existing peripheral neuropathy were unlikely to develop worsening peripheral neuropathy during treatment with zelenectide pevedotin.
The global Phase 2/3 Duravelo-2 registrational trial of zelenectide pevedotin in patients with mUC is currently enrolling. Additional data updates for zelenectide pevedotin in combination with pembrolizumab in first line mUC and monotherapy in late line triple-negative breast cancer and non-small cell lung cancer (NSCLC) are planned for later this year.
BT5528 is a BTC molecule targeting EphA2, a tumor antigen that is widely expressed in many cancers and has historically been difficult to target using other drug conjugate approaches. Updated results from the ongoing Phase 1/2 trial evaluating 6.5 mg/m2 every two weeks and 5 mg/m2 weekly of BT5528 monotherapy in patients with advanced solid tumors showed:
Among 113 efficacy-evaluable patients, a 12% ORR in patients with advanced solid tumors.
The highest anti-tumor activity in mUC, with a 34% ORR in all efficacy-evaluable patients enrolled in the dose escalation and expansion cohorts. Among patients receiving 6.5 mg/m2 every two weeks, a 31% ORR was observed in the dose escalation and expansion cohort and a 45% ORR was observed in the expansion cohort only. A lower but acceptable ORR of 27% was observed in patients receiving 5 mg/m2 weekly.
No objective responses in patients with ovarian cancer who received 5 mg/m2 weekly. However, 5 patients maintained stable disease.
A suggested correlation between EphA2 expression and response. Among 14 patients with mUC who had available immunohistochemistry and response data, a 43% ORR was observed in EphA2-positive patients compared to a 20% ORR in EphA2-negative patients.
A clearly differentiated emerging safety profile, with none of the hemorrhage events or hematological toxicities that have been associated with other EphA2-targeting drug conjugates.
The company has begun assessing BT5528 at 6.5 mg/m2 every two weeks in combination with nivolumab. Results from this cohort are expected in 2025.
Low rates of treatment-related peripheral neuropathy (TRPN) following monotherapy treatment with BTC molecules zelenectide pevedotin or BT5528. In 149 patients treated with zelenectide pevedotin and 74 patients treated with BT5528 from ongoing Phase 1/2 studies, results showed:
TRPN in 28% of patients treated with zelenectide pevedotin and 19% of patients treated with BT5528, nearly all of which were low grade (1-2). One Grade 3 event (neuralgia) was reported in a patient treated with zelenectide pevedotin following prior therapy with enfortumab vedotin. No Grade 3-4 events were observed for BT5528.
Among zelenectide pevedotin-treated patients with peripheral neuropathy at baseline, 80% did not develop TRPN during treatment.
TRPN resulted in few dose modifications across the overall patient populations for zelenectide pevedotin and BT5528, and no drug withdrawals were necessary for either BTC molecule.
TRPN had completely resolved in 14% (zelenectide pevedotin) and 21% (BT5528) of patients, and 26% and 21%, respectively, had some resolution or improvement at time of reporting, though post-treatment follow-up was limited. Median time to resolution or improvement of TRPN was 2.2 weeks for zelenectide pevedotin and 1.7 weeks for BT5528.
The data support the hypothesis that the antibody-drug construct may be a primary driver of peripheral neuropathy rather than MMAE toxicity as was previously believed.
BT7480 is a Nectin-4 targeted CD137 agonist designed to overcome immune agonist toxicities and activate the immune system in Nectin-4 expressing tumors. Initial data from the Phase 1/2 dose escalation trial evaluating BT7480 in patients with advanced solid tumors showed:
Among 39 patients assigned to receive one of 10 different doses (0.002-3.5 mg/kg weekly) of BT7480, an emerging differentiated safety and tolerability profile with a low number of severe adverse events. Low rates of Grade ≥3 TRAEs (5%) and of treatment-related severe adverse events (TRSAEs) (8%) were reported, with no such events among those receiving the highest dose of 3.5 mg/kg.
Best overall response of stable disease in 13 patients, 5 of whom had NSCLC. Stable disease was prolonged (>8 months) in 3 patients, 2 with NSCLC and 1 with anal cancer. There were 2 unconfirmed partial responses, both in patients with cervical cancer.
Preliminary biomarker analyses that support BT7480 dual targeting of CD137 and Nectin-4 as demonstrated by enhanced immune cell activation, aligned with the proposed mechanism of action of BT7480.
As the maximum tolerated dose for BT7480 has not yet been reached, the company is continuing dose exploration in combination studies, starting with nivolumab.
The posters are available in the Publications section of the Bicycle Therapeutics website.