Ash 2020 preview – Novartis touts its Tasigna follow-on

After years in relative obscurity Novartis’s BCR-ABL tyrosine kinase inhibitor asciminib could give the Swiss group’s chronic myelogenous leukaemia franchise a third pillar, late-breaking pivotal data to be presented at the Ash conference suggest.

The presentation, from the Ascembl study pitting asciminib against Pfizer’s Bosulif in third-line or later CML, will be of major interest for investors focusing on blood cancers. Other Ash oncology data include a large array of bispecific antibodies, among which two anti-CD20 assets come from Roche.

For Novartis asciminib is a valuable asset. Its Gleevec blockbuster was the first drug targeting the BCR-ABL oncoprotein to be launched for CML, and it revolutionised treatment of this disease.

Me-too assets followed from Bristol Myers Squibb (Sprycel), Pfizer (Bosulif) and Takeda (Iclusig), and Novartis’s own Tasigna is an important first-line drug too. However, Gleevec is now off patent, and Tasigna only has three years’ exclusivity left.

Now Novartis reckons to have a mechanistic ace up its sleeve. Unlike the approved BCR-ABL assets asciminib specifically hits the oncoprotein’s ABL myristoyl pocket, a first-in-class approach that the group claims could combat the build-up of resistance pathways.

The 233-patient Ascembl trial was said in August to have read out positively, and the Ash late-breaker reveals a 24-week molecular response rate, its primary endpoint, of 25.5% for asciminib versus 13.2% for Bosulif, with the difference yielding a p value of 0.029. Severe adverse events occurred less frequently with asciminib than with Bosulif.

As the study enrolled subjects who had failed two or more therapies, data discussion at Ash might focus on baseline imbalances: 52% and 28% of asciminib subjects were third and fourth line respectively, versus 40% and 38% for Bosulif; asciminib’s advantage over the Pfizer drug was most pronounced in third-line subjects.

The detail might be important in determining how big a slice of the CML market asciminib might seize. Though Bosulif has a first-line label it is usually used second line or later, and Iclusig, a third-generation drug, is an important second-line (and later) option.

If franchise protection is Novartis’s aim with asciminib then similar thinking might lie behind Roche’s development of projects that, like the ageing lymphoma/chronic lymphoblastic leukaemia blockbuster Rituxan, target CD20.

To this end the group is presenting mid-stage clinical data on two anti-CD20 bispecifics, mosunetuzumab and glofitamab, which are both now in phase III. A similarly acting asset, Regeneron’s odronextamab, is earlier in development, and features in the same Ash session.

The response rates seen so far come from early cuts of the data disclosed in the abstracts, but of more importance will be the updates given at Ash itself, which will presumably comprise results at much later cuts.

Immuno-oncology watchers will note the continued presence of assets targeting once hotly touted antigens like Tim3 and Icos, and there is the usual multitude of BCMA-targeting modalities for multiple myeloma, including for instance Abbvie’s TNB-383B.

That last asset might be significant for another reason: Abbvie picked it up from Teneobio last year. With an overall remission rate cited in the abstract of just 52% at the high dose the Ash data could raise further questions about Abbvie’s deal-making prowess.

Ash 2020 will take place in virtual format on December 5-8.

Vantage analysis previously summarised upcoming Ash presentations that resulted in early share price moves, and separately those in non-oncology indications.