Meyd-773 Online
Triple‑negative breast cancer (TNBC) accounts for ~15‑20 % of all breast cancers and is characterized by an aggressive clinical course, early metastasis, and a paucity of targeted therapies (1). Genomic analyses have highlighted the phosphatidylinositol‑3‑kinase (PI3K)/AKT/mTOR axis as a central driver of proliferation, survival, and chemoresistance in TNBC (2,3). While several pan‑class I PI3K inhibitors have entered clinical testing, dose‑limiting toxicities—particularly hyperglycemia, rash, and immune suppression—have limited their therapeutic window (4). Consequently, there is a critical need for next‑generation PI3K inhibitors with improved selectivity, oral bioavailability, and tumor‑specific activity.
Here we report the discovery and preclinical characterization of MEYD‑773, a novel heterocyclic small‑molecule inhibitor derived from a 1,3‑thiazolo[5,4‑d]pyrimidine scaffold. MEYD‑773 was optimized through structure‑activity relationship (SAR) studies to achieve high potency against the p110α catalytic subunit of PI3K, while sparing other class I isoforms (p110β, p110δ, p110γ) and unrelated kinases. We hypothesized that this selectivity would translate into a favorable safety profile and allow sustained inhibition of oncogenic PI3K signaling in TNBC.
Mid‑journey, the ship’s external sensor array detected an unexpected gamma‑ray burst originating from a nearby pulsar, SGX‑19. The burst’s high‑energy photons threatened to ionize the slipstream field, potentially creating a “phase‑gap” that could destabilize the tunnel.
Dr. Armitage ordered a temporary field “re‑phasing”: the PSM’s refractive index was altered to shift the ship’s slipstream trajectory by a fraction of a degree, steering clear of the ionization front. The maneuver succeeded, but it opened a new line of inquiry: could natural high‑energy astrophysical events be harnessed to augment slipstream stability rather than threaten it? MEYD-773
Amazingly, the burst’s photon flux temporarily increased the slipstream’s quantum coherence by 0.04 %. Helios logged the event as a “coherence boost” and flagged it for further study. This serendipitous interaction hinted at a future where slipstream travel might be synchronised with cosmic events, reducing power consumption and extending operational windows.
The DLQSE’s twin reactors flickered to life, the exotic matter cores humming at a frequency of 2.73 × 10⁻⁶ Hz—a resonance that matched the quantum fluctuations of the slipstream field. The ship’s PSM hull began to emit a faint violet luminescence as the field generators aligned.
Helios, the ship’s AI, announced:
“Slipstream field stabilization at 97.3 %. Core temperature within parameters. Initiating quantum tunnel sequence in 3… 2… 1…”
A rippling distortion formed ahead of the ship—a translucent sheet of shimmering spacetime. As the ship’s nose breached the sheet, the crew felt a subtle pressure shift, as if stepping onto a moving walkway made of light. The external world dissolved into a kaleidoscope of stretched starlight, and then, in an instant, the ship was elsewhere.
The transition lasted less than a millisecond from the external observer’s perspective, but for the crew, it felt like a deep breath held and released—a moment of weightlessness followed by a gentle, familiar gravity as the ship re‑engaged its artificial gravity spin. “Slipstream field stabilization at 97
Orthotopic xenograft: 5 × 10⁶ MDA‑MB‑231 cells (luciferase‑expressing) were injected into the fourth mammary fat pad of 6‑week‑old female athymic nude mice (n = 10/group). Treatment started when tumors reached ~100 mm³: vehicle (0.5 % methylcellulose), MEYD‑773 (20 mg kg⁻¹ p.o. qd), paclitaxel (10 mg kg⁻¹ i.p. weekly), or combination. Tumor volume was measured twice weekly by calipers and bioluminescence imaging.
PDX models: Three TNBC PDXs (BRCA1‑mutated, PTEN‑null, PI3K‑wild‑type) were implanted subcutaneously into NOD/SCID mice (n = 8/group). Dosing regimens mirrored the orthotopic study. Survival was defined as time to tumor volume ≥ 1500 mm³.