There is a Bill now before the House in the US Congress that has...

There is a Bill now before the House in the US Congress that has bi-partisan support and, if passed, will increase MSB's opportunities for early approval for CHF and other treatments.

Here is the preamble to the Bill which broadly reflects the sentiments of the large number of lawmakers who think the FDA has not done enough to make available promising new treatments for serious disease. See esp (1) where there are no disease modifying treatments and speed to access is critical (5) allowing reliance on scientifically substantiated surrogates other than those previously validated by the FDA and (7) obligatory reimbursement.

This Bill has no bearing on GvHD approval, but if it is passed then other approvals could follow quite quickly.

A BILLTo amend the Federal Food, Drug, and Cosmetic Act to establish a time-limited provisional approval pathway....
SECTION 1. SHORT TITLE.This Act may be cited as the “Promising Pathway Act”.
SEC. 2. FINDINGS.Congress finds as follows:
(1) The drugs and biological products intended to be reviewed under the pathway established under this Act are for the treatment and prevention of serious diseases or conditions, especially those for which there are no available on-label meaningful or disease-modifying treatments, where speed to access is critical.
2) The approval pathway established under this Act is intended to allow drug and biological product applications to be more rapidly reviewed by the U.S. Food and Drug Administration (FDA), with the FDA reviewing various portions of new drug and biological product applications as they become available.
(3) The approval pathway established under this Act establishes a clear approval pathway that can be utilized by sponsors to receive rolling review of applications for drugs and biological products intended to treat serious diseases, including drugs and biological products intended to treat COVID–19 that reduce the risk of death, severe disease, and progression of symptoms in those exposed to the virus.
(4) The approval pathway established under this Act will enable sponsors to receive early, time-limited, and provisional approval for drugs and biological products that have demonstrated substantial evidence of safety and relevant early evidence that establishes that the drug provides a positive therapeutic outcome.
(5) The approval pathway established under this Act will allow for the use of real-world evidence and scientifically substantiated surrogates, other than those previously validated by the FDA, to predict the clinical benefits and ultimately support provisional approval.
(6) Drugs and biological products granted provisional approval under the pathway established under this Act are limited to a 2-year approval period, renewable every 2 years, for up to 6 years. Full approval can awarded at any time, for any drug or biological product provisionally approved under this pathway that establishes a 15 percent improvement in an important endpoint compared to standard therapies.
(7) The approval pathway established under this Act prohibits denial of coverage for any drug or biological product provisionally approved under this approval pathway on account of it being experimental.
...
Something to keep an eye on for MSB's other treatments especially CHF.