A compound of formula (I) wherein R.sup.L is a linker for connection to a cell binding agent.

##STR00001##

The present invention is directed to novel heteroaryl sulfone-based conjugation handles of the formula: (wherein R.sup.1, R.sup.2, Het, D, E, X, Y, Z, m, n, p, q, r, s and t are as defined herein), methods for their preparation, their use in synthesizing antibody drig conjugates, and the resulting antibody drig conjugates made with components having heteroaryl sulfone-based conjugation handles.

##STR00001##

The present invention provides Ligand-Drug Conjugates, Drug-Linkers, Linkers, and Ligand-Linker Conjugates comprising a self-stabilizing linker assembly component.

The invention provides a new oligopeptide linker intermediate and a preparation method thereof. The preparation method of the oligopeptide intermediate is easily carried out under mild reaction conditions, and since almost no side reactions occur in the reaction, the method produces a high-purity product with fewer impurities and easy to be purified, achieving unexpected technical effects.

Pharmaceutical compositions of the invention include substituted riluzole prodrugs useful for the treatment of cancers including melanoma, breast cancer, brain cancer, and prostate cancer through the release of riluzole. Prodrugs of riluzole have enhanced stability to hepatic metabolism and are delivered into systemic circulation by oral administration, and then cleaved to release riluzole in the plasma via either an enzymatic or general biophysical release process.

Pharmaceutical compositions of the invention include substituted riluzole prodrugs useful for the treatment of cancers including melanoma, breast cancer, brain cancer, and prostate cancer through the release of riluzole. Prodrugs of riluzole have enhanced stability to hepatic metabolism and are delivered into systemic circulation by oral administration, and then cleaved to release riluzole in the plasma via either an enzymatic or general biophysical release process.

The present invention provides pyridazine derivatives of formula (I), which are therapeutically useful as SMARCA2/4 degraders. These compounds are useful in the treatment and/or prevention of diseases or disorders dependent upon SMARCA2/4 in a mammal. The present invention also provides preparation of the compounds and pharmaceutical compositions of at least one of the pyridazine derivatives of formula (I) or a pharmaceutically acceptable salt, or a stereoisomer thereof.

##STR00001##

In one aspect, an active agent-conjugate, methods of preparing the active agent-conjugate, and uses thereof is provided.

Provided are a linker represented by Formula I or I′, an antibody-drug conjugate containing the same, and use of thereof, a pharmaceutical composition comprising the antibody-drug conjugate, and use of the antibody-drug conjugate for treating and/or preventing a disease.

##STR00001##

The present invention concerns the separation, identification and characterization of active peptide fragments from peptones.