Item 7.01 Regulation FD Disclosure.
On June 4, 2023, Day One Biopharmaceuticals, Inc., or the Company, updated its corporate presentation with information presented at the American Society of Clinical Oncology 2023 Annual Meeting, or the ASCO Presentation. The ASCO Presentation included new and updated clinical data from the Company’s ongoing pivotal Phase 2 FIREFLY-1 trial, or the FIREFLY-1 trial, of tovorafenib (DAY101) for pediatric patients with relapsed or progressive low-grade glioma.
Additionally, on June 4, 2023, the Company issued a press release announcing the new and updated clinical data from the FIREFLY-1 trial.
A copy of the revised corporate presentation is attached as Exhibit 99.1 to this Current Report on Form 8-K. A copy of the press release is attached as Exhibit 99.2 to this Current Report on Form 8-K.
The information furnished in this Item 7.01, including Exhibits 99.1 and 99.2, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or the Exchange Act, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any other filing under the Exchange Act or the Securities Act of 1933, as amended, except as expressly set forth by specific reference in such a filing.
Item 8.01 Other Events.
On June 4, 2023, the Company announced new and updated clinical data from the FIREFLY-1 trial. Program updates and updated data are summarized as follows:
FIREFLY-1 Program Update
In May 2023, the Company initiated a rolling review of a New Drug Application to the U.S. Food and Drug Administration, or the FDA. The rolling review allows the Company to submit portions of the regulatory application and have them reviewed by the FDA on an ongoing basis. The Company anticipates the rolling NDA review of tovorafenib will be complete in October 2023 following submission of an amended clinical study report, or CSR, that will include safety and efficacy data from a planned June 2023 data cutoff.
Updated FIREFLY-1 Data
FIREFLY-1, an open-label, pivotal Phase 2 trial, treated 77 patients and evaluated tovorafenib as a once-weekly monotherapy in patients aged 6 months to 25 years with relapsed or progressive pLGG (Arm 1). The primary endpoint of the FIREFLY-1 trial is overall response rate, or ORR, by Response Assessment for Neuro-Oncology High-Grade Glioma, or RANO-HGG, criteria as assessed by blinded independent central review. Secondary endpoints include ORR by Response Assessment in Pediatric Neuro-Oncology Low-Grade Glioma, or RAPNO-LGG, progression-free survival, duration of response, or DOR, time to response, clinical benefit rate and safety. The study also includes an exploratory analysis of ORR by Response Assessment Neuro-Oncology Low-Grade Glioma, or RANO-LGG.
Patient demographics in registrational Arm 1 (n=77):
| | • | | 83% (n=64) of patients had a BRAF fusion, for which there are no approved systemic therapies, while the remaining 17% (n=13) had a BRAF V600E mutation |
| | • | | Participants were heavily pretreated, with a median of two prior lines of systemic therapy (range: 1-9) and 49% (n=38) of patients having 3 or more prior lines of therapy |
| | • | | 60% (n=46) of patients had already received at least one prior MAPK inhibitor prior to study participation |
RANO-HGG (n=69) data:
| | • | | 67% ORR by RANO-HGG, the primary endpoint of the trial |
| | • | | 93% clinical benefit rate (complete response, or CR, + partial response, or PR, + stable disease, or SD) |
| | • | | 61% (n=42) PR, including 3 unconfirmed partial response, or uPR |
| | • | | At the time of data cutoff, the median DOR based on RANO-HGG criteria was not yet reached (95% CI: 9.0 months, not estimable) |
Among a total of 77 treated patients:
| | • | | The median duration of tovorafenib treatment was 10.8 months, with 74% (n=57) of patients on treatment at the time of data cutoff |
Safety data, based on the 136 patients treated in both Arm 1 and Arm 2 of FIREFLY-1, indicated monotherapy tovorafenib to be generally well-tolerated. The vast majority of adverse events were Grade 1 or Grade 2, with most common side effects reported related to tovorafenib being change in hair color (71%), fatigue (50%), vomiting (43%), maculopapular rash (41%) and headache (39%). The most commonly reported lab abnormalities were CPK elevation, anemia, hypophosphatemia and AST elevation. Nearly all of the lab abnormalities had no clinical manifestations and did not require clinical intervention or change in study treatment.
Additional Secondary and Exploratory Endpoint Analyses
The Company also shared the evaluation of responses by RAPNO-LGG and RANO-LGG. Those results include:
| | • | | 51% (n=35) ORR by RAPNO-LGG |
| | • | | 25% (n=17) PR, including 4 uPR |
| | • | | 26% (n=18) minor response, or MR, including 4 uMR |
| | • | | 36% (n=25) patients with SD |
| | • | | The median time to response was 5.5 months for confirmed responses |
| | • | | At the time of data cutoff, the median Independent Review Committee, or IRC, assessed DOR based on confirmed RAPNO-LGG responses is 12 months (95% CI: 11.2, not estimable) |
RANO-LGG (n=76) data:
| | • | | 49% (n=37) ORR by RANO-LGG |
| | • | | 26% (n= 20) PR, including 8 uPR |
| | • | | 22% (n= 17) MR, including 2 uMR |
| | • | | 34% (n=26) patients with SD |
| | • | | The median time to response was 4.2 months for confirmed responses |
| | • | | At the time of data cutoff, the median IRC-assessed DOR based on confirmed RANO-LGG responses is 14.4 months (95% CI: 8.4, not estimable) |
Item 9.01 Financial Statements and Exhibits
(d) Exhibits
Forward-Looking Statements
This Current Report on Form 8-K contains forward-looking statements within the meaning of the U.S. Private Securities Litigation Reform Act of 1995 and other federal securities laws. Any statements contained herein that do not describe historical facts, including, but not limited to, statements we make regarding our ability to obtain regulatory approval for, and commercialize, tovorafenib, our future results of operations and financial position, business strategy, market size, potential growth opportunities, nonclinical and clinical development activities, efficacy and safety profile of our product candidates, potential therapeutic benefits and economic value of our product candidates, our ability to maintain and recognize the benefits of certain designations received by product candidates, the timing and results of nonclinical studies and clinical trials, commercial collaboration with third parties, and our ability to recognize milestone and royalty payments from commercialization agreements, the expected impact of global business or macroeconomic conditions, including as a result of inflation, rising interest rates, instability in the global banking system, and geopolitical conflict, on our operations, and the receipt and timing of potential regulatory designations, approvals and commercialization of product candidates. Such risks and uncertainties include, among others, the risks identified in the Company’s filings with the SEC, including its Quarterly Report on Form 10-Q for the quarter ended March 31, 2023, filed with the SEC on May 1, 2023, and other reports as filed with the SEC. The Company cautions you not to place undue reliance on any forward-looking
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