Het is speculatief, maar met name om de stappen die ze zetten met endoxifen:
Endoxifen is a tamoxifen metabolite that is responsible for much of the oral drug’s selective estrogen receptor modulation (SERM) action. Atossa believes that topical endoxifen can exert SERM effects to breast tissue and reduce elevated mammographic breast density (MBD), with fewer significant adverse events. It also believes that topical endoxifen can safely reduce gynecomastia (male breast enlargement).
Atossa is also developing an oral endoxifen formulation with the aim to reduce breast cancer risk. About 20% of the 300,000 US women currently taking tamoxifen (largely to prevent recurrence of breast cancer) do not achieve sufficient concentrations of endoxifen and may have increased risk of cancer recurrence. Atossa believes that oral endoxifen can reduce recurrence risk in these patients, having completed a Phase I oral endoxifen trial in 2017, and we believe it plans to start a Phase II study in tamoxifen-refractory women in 2019. The oral formulation is also being evaluated in a pilot Australia-based study (which began in July 2018) designed to assess the drug in the ‘window of opportunity’ (WOO) between estrogen receptor-positive (ER+) breast cancer diagnosis and surgery (in patients requiring mastectomy or lumpectomy). The primary endpoint is to determine if the administration of oral endoxifen reduces the tumor activity as measured by Ki-67, which is a marker of cellular proliferation. The study plans to recruit eight patients and if at least two of these show a Ki-67 response (suggestive of tumor activity reduction), it will be increased to 25 subjects.
FDA approves continued endoxifen use for single US patient
Atossa announced in March 2019 that it received a "Safe to Proceed" letter under the FDA’s expanded access program (EAP), which allowed the use of oral endoxifen as a post-mastectomy treatment in a single pre-menopausal, ER+ breast cancer patient who had previously already completed a three-week course of endoxifen prior to surgery under an FDA EAP. Tumor activity from the initial biopsy was compared to activity at surgery, and results showed the cancer cell biological activity was reduced by two measures: the Ki-67 activity decreased by 50 percent, and ER content decreased by over 20 percent. There were no reported safety or tolerability issues. These results suggest that the endoxifen course may have benefited the patient prior to surgery and management reported that the FDA agreed that continued endoxifen therapy may be appropriate for this patient. Under the FDA EAP, the use of endoxifen is restricted solely to this patient for the time being. We expect that the company is continuing to evaluate study options for oral endoxifen in the US beyond its planned cancer recurrence prevention study in patients refractory to tamoxifen.