the patients’ treatment period. One CLL patient experienced multiple enlarged tender diseased lymph nodes one week after first dosing that subsequently regressed, reminiscent of a tumor flare reaction that has been reported as a potential sign of anti-tumor activity in CLL patients treated with another immuno-oncology drug. The patient was assessed as stable disease at the pre-planned 12 week on-study assessment along with a significant reduction in clonal B-cell count. Dosing in the study is continuing, with subsequent cohorts planned to enroll patients in separate cohorts for intravenous and subcutaneous dosing. Additional clinical data from the study are expected in the fourth quarter of 2022 and the first half of 2023.
In 2022, we dosed the first patient in a Phase 1/2a clinical trial evaluating LAVA-1207 in patients with metastatic castration-resistant prostate cancer (mCRPC). The open-label, multi-center, Phase 1/2a clinical trial will evaluate safety, tolerability, pharmacokinetics, pharmacodynamics, immunogenicity and preliminary anti-tumor activity of LAVA-1207. The Phase 1 dose-escalation phase will determine a recommended Phase 2a dose of LAVA-1207. Once a recommended Phase 2 dose has been established, the trial will expand into the Phase 2a portion to confirm safety and evaluate the preliminary anti-tumor activity of LAVA-1207 in patients with mCRPC.
We received regulatory approval for our Clinical Trial Application (CTA) and clearance from the FDA for a Phase 1/2a clinical trial for LAVA-1207. Enrollment for the Phase 1/2a clinical trial for LAVA-1207 is ongoing and being conducted in Europe and the United States. We currently expect to have initial data from the Phase 1 dose escalation phase of the trial in the fourth quarter of 2022 and additional data in the first half of 2023.
In September 2022, we entered into an exclusive worldwide license agreement with Seagen Inc. (Seagen) to develop, manufacture and commercialize LAVA-1223, an advanced preclinical asset that utilizes LAVA’s proprietary Gammabody technology to target epidermal growth factor receptor (EGFR)-expressing solid tumors. Under the terms of the agreement, we received a $50 million nonrefundable upfront payment in October 2022 and could receive approximately $650 million in potential development, regulatory and commercial milestones, and royalties ranging from the single digits to the mid-teens on future sales. The agreement also provides Seagen with the opportunity to exclusively negotiate rights to apply LAVA's proprietary Gammabody platform on up to two additional tumor targets.
We are also developing LAVA-1266, a CD123 Gammabody for the treatment of hematologic malignancies, for which we intend to file a CTA and/or IND in 2024.
We were incorporated in February 2016 in the Netherlands. In 2019, we established our wholly owned U.S. subsidiary, which began business in January 2020. We have not generated any revenue from the sale of products. Since inception, we have incurred recurring losses. As of September 30, 2022, we had an accumulated deficit of $93.5 million.
Effective November 1, 2022, the Board of Directors appointed Fred Powell as Chief Financial Officer.
Factors affecting our Financial Condition and Results of Operations
Impact of COVID-19 Pandemic
In March 2020, the COVID-19 virus caused a worldwide pandemic. Although the pandemic has impacted the timing of onboarding investigational sites and enrolling patients in our ongoing Phase 1/2a clinical trial for LAVA-051 and LAVA-1207, to date we have not experienced any material business disruption or impact to our condensed consolidated interim financial statements as a result of the pandemic.
As our financial condition and results of operations are most affected by our capital resources, continued research and development expenses and general and administrative expenses, the following may have an impact in the future:
| ● | availability of supplies and equipment for our laboratories; |