Sangamo Therapeutics 8K Other Events

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): February 6, 2025

SANGAMO THERAPEUTICS, INC.

(Exact name of registrant as specified in its charter)

Delaware

000-30171

68-0359556

(State or other jurisdiction of
incorporation)

(Commission
File Number)

(IRS Employer
ID Number)

501 Canal Blvd., Richmond, California 94804

(Address of principal executive offices) (Zip Code)

(510) 970-6000

(Registrant’s telephone number, including area code)

Not Applicable

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:


☐			Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)


☐			Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)


☐			Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))


☐			Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class

Trading Symbol(s)

Name of each exchange on which registered

Common Stock, $0.01 par value per share

SGMO

Nasdaq Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 8.01 Other Events.

On February 6, 2025, Sangamo Therapeutics, Inc. (“Sangamo” or the “Company”) announced updated preliminary clinical data from its Phase 1/2 STAAR study evaluating isaralgagene civaparvovec, or ST-920, a wholly owned gene therapy product candidate for the treatment of Fabry disease, in advance of a presentation at the 21st Annual WORLDSymposium on February 6, 2025. A summary of the data is below. This announcement included data on the 33 patients treated with isaralgagene civaparvovec as of the data cutoff date of September 12, 2024.

Enrollment and dosing are complete in the Phase 1/2 STAAR study. In October 2024, Sangamo announced that the FDA had provided a clear regulatory pathway to Accelerated Approval for isaralgagene civaparvovec using data from ongoing Phase 1/2 STAAR study, avoiding the requirement for an additional registrational study and accelerating estimated time to potential approval by approximately three years. The FDA agreed in a Type B interaction that data from the ongoing Phase 1/2 STAAR study can serve as the primary basis for approval under the Accelerated Approval Program, using eGFR slope at 52 weeks across all patients as an intermediate clinical endpoint. The 52-week eGFR slope data from all enrolled patients in the Phase 1/2 STAAR study is expected to be available in the first half of 2025. A potential Biologics License Application (BLA) submission is anticipated in the second half of 2025. Sangamo continues to advance business development discussions for a potential ST-920 collaboration agreement.

Summary of Updated Preliminary Clinical Data from Phase 1/2 STAAR Study of Isaralgagene Civaparvovec Announced on February 6, 2025 in Advance of Presentation at 21st Annual WORLDSymposium on February 6, 2025

•The STAAR study is an ongoing Phase 1/2 multicenter, open-label, dose-ranging clinical study designed to assess a single infusion of isaralgagene civaparvovec in Fabry disease patients ≥ 18 years of age. Patients are infused intravenously with a single dose and followed for 52 weeks. A separate long-term follow-up study is underway to monitor the patients treated in this study for up to five years following treatment. Patients who are on stable enzyme replacement therapy (“ERT”) may withdraw ERT after treatment in a controlled and monitored fashion at the discretion of the patient and the investigator.

•The dose escalation phase included males with classic Fabry disease. The subsequent study expansion phase, which commenced in the second half of 2022, treated females, as well as patients with more severe Fabry-associated cardiac or renal disease. The study’s primary endpoint is the incidence of treatment-emergent adverse events (“AEs”). Additional safety evaluations include routine hematology, chemistry, and liver tests; vital sign monitoring; electrocardiogram; echocardiogram; serial alpha-fetoprotein testing and magnetic resonance imaging (“MRI”) of the liver to monitor for potential formation of any liver mass. Secondary endpoints include change from baseline at specific time points in alpha‑galactosidase A (“α‑Gal A”) activity, globotriaosylceramide (“Gb3”) and lyso‑Gb3 levels in plasma; frequency of ERT infusion; and changes in renal function and cardiac function (left ventricular mass) measured by cardiac MRI and rAAV2/6 vector clearance. Key exploratory endpoints include quality of life, Fabry symptoms and neuropathic pain scores; gastrointestinal symptoms, and immune response to AAV6 capsid and α‑Gal A.

•As of the September 12, 2024 data cutoff date, 33 patients ranging in age from 18 to 67 years were treated with isaralgagene civaparvovec, nine in the dose escalation phase and 24 in the expansion phase of the study. Baseline characteristics of these 33 dosed patients are shown in Table 1 below. In the dose escalation phase, two patients were dosed in Cohort 1 at the dose of 0.26x1013 vg/kg, two patients were dosed in Cohort 2 at the dose of 0.53x1013 vg/kg, three patients were dosed in Cohort 3 at the dose of 1.58x1013 vg/kg, and two patients were dosed in Cohort 4 at the dose of 2.63x1013 vg/kg. In the expansion phase, 24 patients were dosed at the dose of 2.63x1013 vg/kg. As of the September 12, 2024 data cutoff date, the first dosed patient had been followed for at least 47.3 months post dosing, and the most recently dosed patient had been followed for 20 weeks post dosing, as shown in Figure 2 below.

•As of the September 12, 2024 data cutoff date, isaralgagene civaparvovec continued to be generally well-tolerated across all the dose cohorts, with the majority of AEs being graded as mild (Grade 1) or moderate (Grade 2) in nature. No liver function test elevations post-dosing requiring steroids occurred. A summary of the treatment-related AEs reported as of the September 12, 2024 cutoff date is shown in Table 3 below. Treatment-emergent serious AEs were reported in four patients: left arm pain; non-cardiac chest pain, sepsis, stroke and shoulder enthesopathy. No AEs led to study discontinuation. No deaths were reported.

•As of the September 12, 2024 data cutoff date, all ERT naïve or pseudo-naïve patients showed sustained elevated α-Gal A activity up to 42 months for the longest treated patient, and up to 27 months for the longest treated patient receiving the highest dose level (2.63 x 1013 vg/kg), as shown in Figure 4. Sustained elevated expression of α-Gal A activity was accompanied by the reduction and/or long-term stabilization of lyso-Gb3 levels, with the largest reductions in plasma lyso-Gb3 seen in patients with the highest levels at baseline, as shown in Figure 5.

•18 patients began the study on ERT. 17 out of 18 patients had been withdrawn from ERT as of the data cutoff. The remaining patient was withdrawn from ERT after the data cutoff. All 18 patients remain off ERT as of February 6, 2025. Timing of ERT withdrawal was at the discretion of the investigator, to occur no earlier than eight weeks post dosing with isaralgagene civaparvovec. All patients who began the study on ERT showed sustained elevated α-Gal A activity, as

outlined in Figure 6, except for one patient who exhibited levels below the limit of detection at the time of the data cutoff date. Plasma lyso-Gb3 activity levels remained stable following ERT withdrawal for up to 33 months for the longest treated ERT patient, and up to 19 months for the longest treated ERT patient receiving the highest dose level (2.63 x 1013 vg/kg), as outlined in Figure 7.

•For the 23 patients with at least 12-months of follow up or longer as of the September 12, 2024 data cutoff date, a mean annualized estimated glomerular filtration rate (“eGFR”) slope of 3.061 mL/min/1.73m2/year (95% CI: 0.863, 5.258) was observed, indicating a potential improvement in kidney function.

•For the 23 patients with at least 12-months of follow-up, significant improvements in disease severity, quality of life (“QoL”), and gastrointestinal (“GI”) symptoms were observed. As of the September 12, 2024 data cutoff date, 68% of patients improved their total Fabry Outcome Survey adaptation of the Mainz Severity Score Index (“FOS-MSSI”) score and seven patients improved their FOS-MSSI category compared to baseline, as shown in Table 8. Statistically significant improvements in the short form-36 (“SF-36”) QoL scores were reported, with a mean change in the General Health score of 10.6 (p=0.0020) at week 52. For context, a 3- to 5-point change on any SF-36 score is the minimally clinically important difference. Significant improvements in physical component, bodily pain, physical, vitality, social function, and emotional SF-36 scores were also observed. The GI symptom rating scale (“GSRS”) also demonstrated significant improvements, including the Abdominal Pain, Indigestion, Diarrhea and Constipation Scores.

•Immunogenicity remains an issue with ERT, leading to continued organ impairment. 10 patients had measurable titers of total antibodies (“Ab”) or neutralizing antibodies (“NAb”) against α-Gal A associated with ERT at baseline. As shown in Table 9, following dosing, total Ab or NAb titers decreased markedly in nine patients and became undetectable in seven, or 70% of patients. Treatment did not induce anti-α-Gal A antibodies in seronegative patients.

Table 1: Baseline characteristics: Dose escalation and dose expansion phases

Data cutoff date: September 12, 2024

eGFR, estimated glomerular filtration rate (mL/min/1.73m2); ERT, enzyme replacement therapy; N, number, M, male; F, female

Table 2: Duration of follow-up

Data cutoff date: September 12, 2024

vg/kg, vector genomes per kilogram of total body weight

Subject 14 withdrew Day 148

Table 3: Summary of treatment-emergent AEs in >3 patients of 33 treated patients

Data cutoff date: September 12, 2024

AE, adverse event

Figure 4: Plasma α-Gal A in ERT naïve/pseudo-naïve subjects receiving 2.63×1013 vg/kg (n=13)